车辆工程汽车离合器的外文文献翻译大学论文

CLUTCHThe engine produces the power to drive the vehicle. The drive line or drive train transfers the power of the engine to the wheels. The drive train consists of the parts from the back of the flywh eel to the wheels. These parts include the clutch, th e transmission, the drive shaft, and the final drive assembly (Figure 8-1).The clutch which includes the flywheel, clutch disc, pressure plate, springs, pressure plate cover and the linkage necessary to operate the clutch is a rotating mechanism between t he engine and the transmission (Figure 8-2). It operates through friction which comes from contact between the parts. That is the reason why the clutch is called a friction mechanism. After engagement, the clutch must continue to transmit all the engine torque to the transmission depending on the friction without slippage. The clutch is also used to disengage the engine from the drive train whenever the gears in the transmission are being shifted from one gear ratio to another.To start the engine or shift the gears, the driver has to depress the clutch pedal with the purpose of disengagement the transmission from the engine. At that time, the driven members connected to the transmission input shaft are either stationary or rotating at a speed that is slower or faster than the driving members connected to the engine crankshaft. There is no spring pressure on the clutch assembly parts. So there is no friction between the driving members and driven members. As the driver lets loose the clutch pedal, spring pre ssure increases on the clutch parts. Friction between the parts also increases. The pressure exerted by the springs on the driven members is controlled by the driver through the clutch pedal and linkage. The positive engagement of the driving and driven members is made possible by the friction between the surfaces of the members. When full spring pressure is applied, the speed of the driving and driven members should be the same. At themoment, the clutch must act as a solid coupling device and transmit al l engine power to the transmission, without slipping.However, the transmission should be engaged to the engine gradually in order to operate the car smoothly and minimize torsional shock on the drive train because an engine at idle just develops little power. Otherwise, the driving members are connected with the driven members too quickly and the engine would be stalled.The flywheel is a major part of the clutch. The flywheel mounts to the engine’s crankshaft and transmits engine torque to the clutch assembly. The flywheel, when coupled with the clutch disc and pressure plate makes and breaks the flow of power from the engine to the transmission.The flywheel provides a mounting location for the clutch assembly as well. When the clutch is applied, the flyw heel transfers engine torque to the clutch disc. Because of its weight, the flywheel helps to smooth engine operation. The flywheel also has a large ring gear at its outer edge, which engages with a pinion gear on the starter motor during engine cranking.The clutch disc fits between the flywheel and the pressure plate. The clutch disc has a splined hub that fits over splines on the transmission input shaft. A splined hub has grooves that match splines on the shaft. These splines fit in the grooves. Thus, t he two parts are held together. However, back-and-forth movement of the disc on the shaft is possible. Attached to the input shaft, At disc turns at the speed of the shaft.The clutch pressure plate is generally made of cast iron. It is round and about the same diameter as the clutch disc. One side of the pressure plate is machined smooth. This side will press th e clutch disc facing are against the flywheel. The outer side has various shapes to facilitate attachment of spring and release mechanisms. The two primary types of pressure plate assemblies are coil spri ng assembly and diaphragmspring (Figure 8-3).In a coil spring clutch the pressure plate is backed by a number of coil springs and housed with them in a pressed-steel cover bolted to the flywheel. The springs push against the cover. Neither the driven plate nor the pressure plate is connected rigidly to the flywheel and both can move either towards it or away. When the clutch pedal is depressed a thrust pad riding on a carbon or ball thrust bearing i s forced towards the flywheel. Levers pivoted so that they engage with the thrust pad at one end and the pressure plate at the other end pull the pressure plate back against its springs. This releases pressure on the driven plate disconnecting the gearbox from the engine (Figure 8-4).Diaphragm spring pressure plate assemblies are widely used in most modern cars. The diaphragm spring is a single thin sheet of metal which yields when pressure is applied to it. When pressure is removed the metal springs back to its original shape. The centre portion of the diaphragm spring is slit into numerous fingers that act as release levers. When the clutch assembly rotates with the engine these weights are flung outwards by centrifugal forces and cause the levers to pre ss against the pressure plate. During disengagement of the clutch the fingers are moved forward by the release bearing. The spring pivots over the fulcrum ring and its outer rim moves away from the flywheel. The retracting spring pulls the pressure plate a way from the clutch plate thus disengaging the clutch (Figure 8-5).When engaged the release bearing and the fingers of the diaphragm spring move towards the transmission. As the diaphragm pivots over the pivot ring its outer rim forces the pressure plate against the clutch disc so that the clutch plate is engaged to the flywheel.The advantages of a diaphragm type pres sure plate assembly are its compactness, lower weight, fewer moving parts, less effort to en gage, reduces rotational imbalance by providin g a balanced force around the pressure plate and less chances of clutch slippage.The clutch pedal is connected to the disengagement mechanism either by a cable or, more com monly, by a hydraulic system. Either way, pushing the pedal down operates the dise ngagement mechanism which puts pressure on the fingers of the clutch diaphragm via a release bearing and causes the diaphragm to release the clutch plate. With a hydraulic mechanism, the clutch pedal arm operates a piston in the clutch master cylinder. Thi s forces hydraulic fluid through a pipe to the clutch release cylinder where another piston operates the clutch disengagement mechanism. The alternative is to link the clutch pedal to the disengagement mechanism by a cable.The other parts including the cl utch fork, release bearing, bell-housing, bell housing cover, and pilot bushing are needed to couple and uncouple the transmission. The clutch fork, which connects to the linkage, actually operates the clutch. The release bearing fits between the clutch fork and the pressure plate assembly. The bell housing covers the clutch assembly. The bell housing c over fastens to the bottom of the bell housing. This removable cover allows a mechanic to inspect the clutch without removing the transmission and bell housing. A pilot bushing fits into the back of th e crankshaft and holds the transmission input shaft.Torque ConverterThe BasicsJust like manual transmission cars, cars with automatic transmissions need a way to let the en gine turn while the wheels and gears in the transmission come to a stop. Manual transmission cars use a clutch, which completely disconnects the engine from the transmission. Automatic transmis sion cars use a torque converter.A torque converter is a type of fluid coupling, which allows the engine to spin somewhat independently of the transmission. If the engine is turning slowly, such as when the car is idling at a stoplight,the amount of torque passed through the torque converter is very small, so keeping the car still requires only a li ght pressure on the brake pedal.If you were to step on the gas pedal while the car is stopped, you would have to press harder on the brake to keep the car from moving. This is because when you step on the gas, the engine speeds up and pumps more fluid into the torque converter, causing more torque to be transmitted to the wheels.Inside a Torque ConverterThere are four components inside the very strong housing of the torque converter:1. Pump;2. Turbine;3. Stator;4. Transmission fluid.The housing of the torque converter is bolted to the flywheel of the engine, so it turns at what ever speed the engine is running at. The fins that make up the pump of the torque converter are at tached to the housing, so they also turn at the same speed as the engine. The cutaway below shows how everything is connected inside the torque converter (Figure 8-6).The pump inside a torque converter is a type of centrifugal pump. As it spins, fluid is flung to the outside, much as the spin cycle of a washing machine flings water and clothes to the outside of the wash tub. As fluid is flung to the outside, a vacuum is created that draws more fluid in at the center.The fluid then enters the blades of the turbine, which is connected to the transmission. The turbine causes the transmission to spin, which basically moves the car. The blades of the turbine are curved. This means that the fluid, which enters the turbine from the outside, has to change direction before it exits the center of the turbine. It is this directional change that causes the turbine to spin.The fluid exits the turbine at the center, moving in a different direction than when it entered. The fluid exits the turbine moving opposite the direction that the pump (and engine) is turning. If the fluid were allowed to hit the pump, it would slow the engine down, wasting power. This is why a torque converter has a stator.The stator resides in the very center of the torque converter. Its job is to redirect the fluid returning from the turbine before it hits the pump again. This dramatically increases the efficiency of the torque converter.The stator has a very aggressive blade design that almost completely reverses the direction of the fluid. A one-way clutch (inside the stator) connects the stator to a fixed shaft i n the transmission. Because of this arrangement, the stator cannot spin with the fluid - i tc a n s p i n o n l y i n t h e o p p o s i t ed i re c t i o n,f o r c i ng th e f l ui d t oc h a n g ed i re c t i o n a s i t h i t s t h e s t a t o r b l a d e s.Something a little bit tricky happens when the car gets moving. There is a point, around 40 mph (64 kph), at which both the pump and the turbine are spinning at almost the same speed (the pump always spins slightly faster). At this point, the fluid returns from the turbine, entering the pump already moving in the same direction as the pump, so the stator is not needed.Even though the turbine changes the direction of the fluid and flings it out the back, the fluid still ends up moving in the direction that the turbine is spinning because the turbine is spinning faster in one direction than the fluid is being pumped in the other direction. If you were standing in the back of a pickup moving at 60 mph, and you threw a ball out the back of that pickup at 40 mph, the ball would still be going forward at 20 mph. This is similar to what happens in the tur bine: The fluid is being flung out the back in one direction, but not as fast as it was going to start with in the other direction.At these speeds, the fluid actually strikes the back sides of the stator blades, causing the stator to freewheel on its one-way clutch so it doesn’t hinder the fluid moving through it.Benefits and Weak PointsIn addition to the very important job of allowing a car come to a complete stop without stalling the engine; the torque converter a ctually gives the car more torque when you accelerate out of a Stop. Modern torque converters can multiply the torque of the engine by two to three times. This effect only happens when the engine is turning much faster than the transmission.At higher speeds, the transmission catches up to the engine, eventually moving at almost the same speed. Ideally, though, the transmission would move at exactly the same speed as the engine, because this difference in speed wastes power. This is part of the reason why cars with automatic transmissions get worse gas mileage than cars with manual transmissions.To counter this effect, some cars have a torque converter with a lockup clutch. When the two halves of the torque converter get up to speed, this clutch locks them together, eliminating the slip page and improving efficiency.离合器发动机产生动力用以驱动车辆。

Clutch technology development historyIn the 100 years of the history of the development of automobile, almost all of the components in terms of technology development have experienced great changes: reliability, production cost, convenient maintenance, energy saving and emission reduction and so on, have been and will always be the automotive industry in the pursuit of goals, these goals for Automotive engineers continue to develop solutions newer and better.Technically, it was not until 1910 that the reciprocating piston internal combustion engine was significantly more efficient than cars and electric vehicles. In 1902, a gasoline engine car first broke the record of the highest speed, and before that, the highest speed record has been created by steam cars and electric cars. Supporters of the three different drivers of the car have been racing and racing for the first ten years of twentieth Century to break the record.Liquid fuel to drive the car to "steam and electric vehicles" (steam and electric vehicle supporters habit called) has a very prominent advantage is its nearly ideal torque characteristics, they do not need a clutch, does not need the transmission, so it is easy to operate, less failure, easier to maintain. Since the reciprocating piston internal combustion engine can only output torque when it reaches a certain speed, it is necessary to have a separate joint between the engine and the transmission. Gasoline engines need to use the clutch engagement function to start the car, because only when the engine reaches a certain speed, the output torque. In addition to the engagement of the clutch, the clutch's separation function is also important because it is free to move in the vehicle. In view of the complexity of the related problems, there is no clutch engagement function in many small car design structures in the early stage.Origin of clutchThe working principle of first generation clutch from the early use of mechanical equipment factory industrial society. Through the analogy of belt transmission, a kind of flat belt is introduced into the car. By means of the tension of the belt pulley, the belt transfers the output torque of the engine to the driving gear, and when the belt is relaxed by adjusting the roller, the belt slipping is equivalent to the separation of the clutch. Because this process causes the abrasion of the belt is too fast, people will adopt a new method: install a drive pulley with the same size of the idler wheel, by pulling the lever, the drive belt from the idler wheel to drive wheel.This belt drive is a disadvantage, low efficiency, easy to wear, especially the transfer of power shortage in rainy days; on the other hand is the requirement of transmission gear to increase engine torque to constantly improve, this has prompted engineers to explore better to replace the clutch.The result is clutch invented a variety of people, including modern clutch pioneer -- Based on the principle of friction clutch. This is a disc located at the end of the crankshaft and connected to another stationary disk. When the two disks are in contact, the friction is produced, and the stationary disk begins to rotate. With the increase of the clamping force, the driving disc drives the driven disc to make thespeed of the driven disk continuously improve until the transmission is working normally, and the two disks rotate at the same speed. Before the two disks are fully engaged, they are in contact with one side and slip, and most of the kinetic energy from the engine is converted into heat. This structure can meet the following two requirements: on the one hand gently gently engage in when starting a car engine will stall, it will not cause the transmission jitter; on the other hand, the clutch can be nondestructively torque to the transmission.Clutch pedal to work through. Press the clutch pedal, pull the conical seat ring through the separation fork, release the spring, so as to separate the clutch.Early clutchIn 1889, Daimler's steel wheel car had used the basic form of this design principle: equipped with a tapered / bevel friction clutch. The freely movable conical disc is located on the transmission shaft, and the flywheel with a tapered groove on the crankshaft can be firmly engaged. The coil spring presses the conical disc into the tapered groove of the flywheel and the clutch is engaged; the foot pedal can be stepped down, and the conical disc can be pulled back by separating the sleeve and the spring, thereby separating the clutch and interrupting the power transmission. Originally used as a conical disc friction surface material, but was quickly replaced the leather. The latter is soaked in castor oil, can prevent moisture, oil / fat. The utility model has the advantages that the utility model can be automatically adjusted, and the input shaft of the transmission is not stressed. On the one hand, the wear of friction plate is too fast, the replacement is too complex, after the friction in the design of the friction plate spring pin or drive to improve. On the other hand, the flywheel and clutch cone is too large, so that the inertia torque is larger and the clutch is much slower than the required separation process.To solve the above problems, around 1910s, with another clutch brake or brake transmission, it through a second foot pedal to play a role, usually the second pedal and the clutch pedal are connected together, and are located in the rear of the pedal shaft.When changing the speed, many drivers are used to make the clutch slipping and not shift, then the flywheel heating degree is more serious than only by the tapered disc friction cone disc by friction layer of leather to heat. After a long period of long-distance driving, due to the thermal expansion of the flywheel, the cone may be more engaging with the flywheel, but when the flywheel temperature drops, it is difficult to separate the cone from the flywheel.Until the first World War period, metal friction began to spread up. Previously, people also experimented with other different materials, such as NAG company designed a camelhair cone disc thin steel sheet pressing, and fitted with a fanlike blade used for cooling, it engages in the two part, bolted to the flywheel on the leather ring line. The two part of the structure allows the free movement of the leather wire ring, thereby simplifying the clutch maintenance and reducing the number of times the clutch is stuck.Daimler motor company has developed an open friction clutch with an aluminum cone. In order to separate the soft, the oil on the friction layer.Because of the simple structure, the cone disc clutch has been the dominant position in the whole 1920s. Cylindrical friction surfaces are not accepted because of their poor operating performance. Only cylindrical clutch spring clutch with the evolution version, due to its creative design, only by Daimler in late nineteenth Century early twentieth Century with the Mercedes Benz car, and continued until the first world war.The traditional single disc dry clutchIn spring clutch, a wearable spiral spring, and the input shaft of the transmission drum end, mounted in the recess of the flywheel. One end of the spiral spring plate is connected with the flywheel, and the other end is fastened on the spring cover. The clutch pedal presses the spring plate, the leaf spring is more and more tight around the drum shape (automatic enhancement), and drives the transmission input shaft. Only a small force can compress the spring and make the clutch soft.About the development of spring clutch in the Daimler company at the same time, Professor Hele-Shaw from the UK also completed the test of multi disc clutch, which is also considered a precursor to the current traditional single disc dry clutch. One of the key advantages of the "Weston" clutch, which can be produced on a large scale, is that it has a large area of friction and can be continuously engaged in a smaller mounting space.In multi disc clutch, flywheel connected to the drum cover, and according to the outer shape of the coil inside the slot, and allow the disc to rotate with the crankshaft and flywheel, and longitudinal movement. The same number of concave disks are positioned in the center of the hub, and the hub is connected to the clutch shaft. These disks can be moved longitudinally along the clutch shaft on the hub. During the installation, the internal and external driven plates of the clutch are alternately connected to form a set of disks, such as the active and driven disks are always connected with each other.The driven disc work like this: start the bronze plate is always facing the steel wheel, and the spiral spring under the pressure plate is pressed together. In this way, all disks are continuously engaged. The gradual increase in the friction force allows the clutch to engage very softly. With the decrease of the spring pressure, the driven plate is separated, and the supporting part of the driving plate starts to bend from the plane of the driven plate. By changing the number of driven disc pairs, the clutch can be adjusted to fit the output power of each engine.Multi disc clutch for oil / gasoline, can also be dry. The dry type is special, and the friction layer is riveted by rivets. Multi disc clutch, especially the oil bath type multi disc clutch, its biggest drawback is a certain degree of hysteresis, which can only be part of the separation, resulting in difficult shift.After several years, single disc clutch has eliminated the cone disc and multi disc clutch. De Dion and Bouton are the first to realize that a single disc clutch is the future direction of the clutch. With the appearance of Ferodo asbestos friction sheet, clutch technology has made great progress. Asbestos friction sheet has been used since 1920s, until it is replaced by non asbestos friction sheet. The advantage of a single disc dry clutch is obvious: the lower drive disc mass allows it to stop fasterafter separation, thus making it easier to shift gears - a complete farewell to the transmission brake structure.The original structure single disc dry relatively complex. The clutch housing is bolted to the flywheel and the clutch cover is bolted to the clutch housing. The clutch cover with the spring to the inner side of the compression lever is transferred from the intermediate plate through the friction disc, and the torque from the flywheel is transmitted to the transmission. The friction disc is connected to the connection or transmission input shaft by the driver. The clutch is separated and joined by means of a sliding ring plate that allows the tapered disc to move forward and backward. Each side of the cone disc acts on the separating lever correspondingly, and the separating lever is operated by a spiral spring, and is pressed or separated. Due to the fact that the cone is rotating and the sliding ring is stationary, it needs to be lubricated periodically.The spiral spring clutch pressing force provided by the spring, won the people's recognition. At first, the coil spring is placed in the middle of the test, but only a few smaller spiral or spiral spring along the outer ring of the clutch housing arrangement of the structure to be mass production. The release lever compresses the coil spring by a separate bearing which can move freely on the transmission input shaft to separate the clutch. The pressing force can be due to the use of different spring and change, but there is a fatal disadvantage, namely with the increase of engine speed, a spiral spring located in the outer ring of the pressure plate, due to the centrifugal force to the spring cover direction to the outward pressure, the friction between the spring and the cover, the pressing force performance curve change.As the engine speed increases, the clutch becomes heavier and heavier. In addition, the separation bearing used to separate the lever has been in a state of pressure, so that it and the clutch cover is easy to wear, especially in the high speed of the engine gear shift, will soon wear.The birth of diaphragm clutchIn order to solve the problems of these systems, we developed a diaphragm spring clutch diaphragm spring clutch, the research laboratory was born in 1936 of general motors, and mass production in late 1930s in the United states. In Europe, after the Second World War, people began to be familiar with the diaphragm spring clutch through the American General Company military truck, and in the middle of 1950s in a number of single European models. Porsche 356, BMW Goggomobil 700 and DKW Munga is the first batch of the diaphragm spring clutch is equipped with German cars. Diaphragm spring clutch mass production began in 1965 with the Opel Rekord models.Because of the diaphragm spring clutch can be balanced and symmetrical rotation, so it is not affected by the engine speed. The diaphragm spring clutch was a success in 1960s, when the camshaft top mounted high speed engine (Glas, BMW, Alpha Romeo) was widely used to replace the camshaft engine. By the end of the 1960s, almost all car manufacturers have adopted diaphragm spring clutch.Here need to emphasize is: let LuK in diaphragm spring clutch mass production, played a crucial role. Replace all the separate lever helical spring system withdiaphragm spring, brings a lot of advantages: simple structure, constant pressing force, installation space is relatively high pressing force only needs a relatively small (very important for transverse engine) and is not affected by the impact of engine speed. Because of these characteristics, almost all of the modern use of diaphragm spring clutch, and its application in the multi-function car is also more and more - has been the use of spiral spring clutch.With the development of correspondingly, clutch disc has been optimized. Reciprocating piston internal combustion engine changes in the speed and torque generated by the vibration of the crankshaft, clutch, transmission input shaft to the transmission, resulting in noise and severe gear wear. In the modern automobile, the weight of the flywheel and the vehicle is increasing, so the clutch driven disc with the torque damper and the wave spring is developed.Long time operated clutch needs a strong thigh, because the pedal force must be transferred through the connecting rod or shaft / cable. With the application of the clutch and the hydraulic separation mechanism in 1950s in 1930s, the driving comfort has been improved.To try different clutch automatic clutch to make operation more simple: in 1918, Wolseley first proposed the concept of electromagnetic clutch. In the early 1930s, the French Cotal company produced a luxury car with a magnetic clutch, a pre selector transmission. The most famous is the centrifugal clutch to adjust the clamping force by centrifugal force and automatic clutch, such as Saxomat (Fichtel & Sax company), LuKomat (LuK), Manumatik (Borg & Beck) and Ferlec (Ferodo).离合器技术发展史在100多年的汽车发展史中，几乎所有的零部件在技术方面都经历过巨大的发展变化：可靠性、生产成本、维护便利性、节能减排性等，都已经且将一直成为汽车行业的追求目标，这些发展目标要求汽车工程师们不断地开发出更新更好的解决方案。

附录How Does the Clutch WorkThe clutch is a device to engage and disengage power from the engine, allowing the vehicle to stop and start.A pressure plate or “driving member” is bolted to the engine flywheel, and a clutch plate or “driven member” is loc ated between the flywheel and the pressure plate. The clutch plate is spline to the shaft extending from the transmission to the flywheel, commonly called a clutch shaft or input shaft. When the clutch and pressure plates are locked together by friction, the clutch shaft rotates with the engine crankshaft. Power is transferred from the engine to the transmission, where it is routed through different gear rations to obtain the best speed and power to start and keep the vehicle moving.The flywheel is located at the rear of the engine and is bolted to the crankshaft. It helps absorb power impulses, resulting in a smoothly-idling engine and provides momentum to carry the engine through its operating cycle. The rear surface of the flywheel is machined flat and the clutch components are attached to it. The driving member is commonly called the pressure plate. It is bolted to the engine flywheel and its main purpose is to exert pressure against the clutch plate, holding the plate tight against the flywheel and allowing the power to flow from the engine to the transmission. It must also be capable of interrupting the power flow by releasing the pressure on the clutch plate. This allows the clutch plate to stop rotating while the flywheel and pressure plate continues to rotate.The pressure plate consist of a heavy metal plate, coil springs or diaphragm spring, release levers (fingers), and a cover. When coil springs are used, they are evenly spaced around the metal plate and located between the plate and the metal cover. This places an even pressure against the plate, which in turn presses the clutch plate tight against the flywheel. The cover is bolted tightly to the flywheel and the metal pate is movable, due to internal linkages. The coil springs are arranged to exert direct or indirect tension on the metal plate, depending upon the manufacturer’s design. Three release levers (fingers), evenly spaced around the cover, are used on most pressure plates to release the holding pressure of the springs on the clutch plate, allowing it to disengage the power flow.When a diaphragm spring is used instead of coil springs, the internal linkage is necessarily different to provide an “over-center” action to release the clutch plate from the flywheel. Its operation can be compared to the operation of an oilcan. When depressing the slightly curved metal on the bottom of the oilcan, it goes over-center and gives out a loud “clicking” noise; when released, the noise is again heard as the metal returns to its originalposition. A click is not heard in the clutch operation, but the action of the diaphragm spring is the same as the oilcan.The clutch plate or driven member consists of a round metal plate attached to a splined hub. The outer portion of the round plate is covered with a friction material of molded or woven asbestos and is riveted or bonded to the plate. The thickness of the clutch plate and /or facings may be warped to give a softer clutch engagement. Coil springs are often installed in the hub to help provide a cushion against the twisting force of engagement. The splined hub is mated to (and turns) a splined transmission shaft when the clutch is engaged.The release (throw out) bearing is usually a ball bearing unit, mounted on a sleeve, and attached to the release or throw out lever. Its purpose is to apply pressure to the diaphragm spring or release levers in the pressure plate. When the clutch pedal is depressed, the pressure of the release bearing or lever actuates the internal linkages of the pressure plate, releasing the clutch plate and interrupting the power flow. The release bearing is not in constant contract with the pressure plate. A linkage adjustment clearance should be maintained.The clutch pedal provides mechanical means for the driver to control the engagement and disengagement of the clutch. The pedal is connected mechanically to either a cable or rods, which are directly connected to the release bearing lever.When the clutch pedal is depressed, the linkage moves the release bearing lever. The release lever is attached at the opposite end to a release bearing which straddles the transmission clutch shaft, and presses inward on the pressure plate gingers or the diaphragm spring. This inward pressure acts upon the fingers and internal linkage of the pressure plate and allows the clutch plate to move away from the flywheel, interrupting the flow of power.While the clutch pedal is depressed and the power flow interrupted, the transmission can be shifted in to any gear. The clutch pedal is slowly released to gradually move the clutch pate toward the flywheels under pressure of the pressure plate springs. The friction between the clutch plate and flywheel becomes greater as the pedal is released and the engine speed increased. Once the vehicle is moving, the need for clutch slippage is lessened, and the clutch pedal can be fully released.Coordination between the clutch pedal and accelerator is important to avoid engine stalling, shock to the driveline components and excessive clutch slippage and overheating.离合器如何工作离合器是传递和分离发动机动力的装置，实现车辆的停车和启动。

湖北文理学院毕业设计(论文)英文翻译题目有限元热分析的陶瓷离合器专业车辆工程班级Xxx姓名Xxxx学号*******xx指导教师职称Xxx 副教授2014年2月25日Fethermal analysis of a ceramic clutch1. IntroductionAbrasive dry running vehicle clutches are force closure couplings. Torque and speed transmission are ensured by the frictional force generated between two pressed surfaces. Reasons for the application of ceramic as a friction medium include good heat and wear resistance properties, which provide the opportunity to drive higher pressures, and a low density. Thus, an increasing power density is enabled with a parallel minimization of construction space.Measurements with a first prototype of a clutch disk using ceramic facings were performed at Karlsruhe University in a laboratory specialized in passenger car drive system testing. In the course of analysis the finite element (FE) model was to be constructed with the knowledge of measurement data and measurement conditions. Calculations were intended to determine the temperature distribution of the clutch disk and its environment at each moment in time corresponding to measurements. It is essential to be familiar with the temperature range in order to examine the wear characteristics of the system. Thus, important information is derived from measurement data. In critical load cases, the highest expected temperatures must be forecast in space and time in order to protect measuring instruments close to the location of heat generation.The goal of this study is to analyze and modify the clutch system to provide better operating conditions by improving the heat conduction and convection of the system or to increase the amount of the energy converted into frictional heat. Furthermore, it is desired to find better design solutions for more efficient clutch systems.Calculations were performed by the Cosmos Design Star software. During model development, great care had to be taken for proper simplification of geometry, the selection of element sizes, and the correct adjustment of time steps due to the substantial hardware requirements for transient calculations. Changes in thermal parameters such as the surface heat convection coefficient and thermal load had to be taken into consideration on an on-going basis in terms of time and location. The two sides of the analyzed test clutch system can only be managed by two independent models linked by heat partition,according to the hypothesis that the contact temperature must be identical on both sides while there is proper contact between them and its value must be adjusted by iteration. Calculations revealed that the heat partition changed by cycle and it differed along the inner and outer contact rings. As a result of the different cooling characteristics between the ceramic and steel side, a heat flow is launched from the ceramic side to the steel side. This heat flow was also determined by iteration, its value also changes by cycle and differs along the inner and outer contact rings.2. First prototype of a clutch using engineering ceramics as friction materialThe examined clutch disk was developed according to the “specific ceramic” product development process established at the Institute for Product Development (IPEK) at the University of Karlsruhe. This development process already has the possibility for connection to a real transmission shaft; further, it has a cushion spring device for the facings allowing good start behaviour. Abrasive clutches must comply with the following basic requirements:●high torque transmission according to high friction coefficients,●high comfort (no vibrations through self-induced chattering),●homogeneous temperature distribution,●low wear characteristic.A critical element of the switch is the abrasive disk.With regard to the design utmost care must be taken to select the right material. A high and constant friction coefficient,，wear resistance and thermal resistance are desired characteristics. The clutch disk has instead of the generally applied ring-shaped abrasive inlet two rows of SSIC (as sintered) ceramic pellets. These pellets are placed on 6 separate segments. The segments are fixed to the central hub by rivets. Each segment consists of 4 plates, 2 working as facing springs and 2 as carriers.3. MeasurementsMeasurements were performed at the department of power train development of the Institute for Product Development (IPEK) at the Karlsruhe University (TH) ResearchUniversity, where a category IV component test rig is used for tests of new frictional materials and examinations of new materials in real clutch disks. Real conditions are applied by the simulation of driving resistance (e.g. starting in the plane, starting at the hill). It is a component test rig leveled on the fourth position of the tribological testing environment.In order to give an idea of dimensions: the equipment length is about 4-5m. The two electric motors and the axial force are controlled independently by computer; thereby many operational states can be realized. This enables the equipment to complete a myriad of tribological measurements all while properly modeling the operation of a clutch disk in a passenger car. It is also equipped with an automatic IT measurement system. Measurable quantities include the following:●two heavy-duty electric motors (150 KW, Baumuller DS 160L-305),●device suitable for exerting axial force,●torque meter (Manner Sensortelemetrie MF100),●axial force meter,●steel disk in friction,●replaceable head to affix the device to be tested,●temperature along two different radii at 0.4mm below the abrasive surface of the steeldisk (Omega HJMTSS-IM100U-150-2000,J-typeiro-constantan thermocouples),●revolutions per minute for both sides (Polytene LSV 065).The greatest challenge out of these is temperature measurement as we would like to know the temperature of the revolving steel disk. The two thermoelements placed in the steel disk forward data to the computer through a wireless blue tooth system and are placed 0.4mm below the abrasive surface of the steel disk on the two opposite arcs of the clutch disk.3.2. Measurement processDue to component analyses and cost reduction only one side of the clutch disk is mounted with ceramic facings. Thus, the clutch disk and its fitting will be referred to as the ceramic side, and the abrasive steel disk with its environment revolving together will be referred to as the steel side. In the course of measurements, data were collected at a sampling frequency of 100 and 1000HZ. Measurements were conducted according to thetime curves.The measurement starts by increasing the revolutions per minute of the steel side (the driving side) to a specific value (1500 rpm here). Then the ceramic side (the driven side), held at zero rpm, is pushed towards the steel disk and the axial force is applied until a designated value is reached (nominally 4200N here). Upon reaching the designated axial force the ceramic side is released and the two sides start to synchronize. A few seconds after synchronization, the axial load is discontinued and after some time both the steel and the ceramic sides—revolving at the same speed—are slowed down. This is deemed to be one measurement cycle. Ten cycles are completed in the course of a single measurement. During application of the axial force the ceramic side is held at zero rpm until the desired force is reached to ensure synchronization occurs at nearly the same time of each cycle. This is unfavorable from the viewpoint of both measurements and calculations. Measurements are usually conducted by changing only 3 parameters: the speed, the axial load and the inertia. The following figures are applied in various combinations:●speed n: 700, 1100 and 1500 (rpm),●axial force F: 4200, 6400 and 8400 (N) and●inertia I: 1, 1.25 and 1.5 (kgm2).Experimental measurements are launched with approx.10-15 min intervals, during which the system cools down to about 30-40 1C. This makes calculations difficult, as the exact temperature distribution of the system is not known at the commencement of the measurement. However, it can be assumed that a period of 10-15min is sufficient for a nearly homogeneous temperature distribution to be produced. The parameters for the following simulation have been chosen for an intermediate case with a speed n =1500 rpm, an axial force F = 4200 N and an inertia I = 1 kg m2.4. Calculations of heat generationThe mechanical energy consumed during the friction of two bodies is transformed into heat. The generated heat can be calculated by the following simple formula: Q =μ·ν·F [W] .where m is the the frictional coefficient; v is the sliding velocity; F is the force perpendicularly compressing the surfaces. And the heat flux density per surface unit isq=μ·ν·p [Wm2].where p is the the pressure calculated as a ratio of the force and the contacting surface. As the ceramic tablets are placed at two different radii along the clutch disk, the heat generated must be calculated separately for each radii. Sliding can be divided into two sections. In the first section, the ceramic side is kept in a stationary position by braking, meanwhile the axial load is increased; therefore compression changes in the course of time while the speed difference between the two sides is constant. In the second section (at synchronization) the speed difference is equalized while the force value is constant, so velocity changes in time. On the basis thereof, the heat generated is.The nominal contact area is the aggregate of the contacting surfaces of the 24 and 18 ceramic tablets on the given ring. The diameter of ceramic tablets is:.Calculations were performed for the load case to be characterized by the following parameters:.Based on experimental measurements a constant friction coefficient of 0.4 was established..The velocity can be calculated with the knowledge of the radius and the speed..Surface pressure can be calculated as a ratio of the axial force and the contacting surface. This produces the same figure for each ceramic pellet, assuming an even load distribution..Thus, the maximum values of the generated heat are.In the first section of sliding, the generated heat is rising due to the increase of the load force; in the second section, it is decreasing due to the equalization of the speed difference. It is necessary to know the time of each sliding section in order to be able to specify the generated heat time curve. These can be determined from measurement data series. Synchronization time can be easily determined from the speed of the ceramic side. Speed increase is linear. Force increase is non-linear. For the sake of simplicity, force increase was substituted by a straight line in calculations so that the area below the straight line is nearly identical with the area measured below the curve. Thus, the time difference between the two terminal points of the straight line is the time of the first sliding section.The above-mentioned method was applied for each cycle and their average was specified. Based on these results, the following values were determined for sliding times:.Now the time curve of heat generation can be produced. The same curve was used in each cycle as there were no significant differences between parameters in each cycle. The generated heat-calculated this way-will appear as thermal load in the thermal model. It must be distributed appropriately between the contacting surfaces by taking intoconsideration heat partition. Heat partition requires the contact temperatures to be identical at both surfaces. Correct adjustment requires repeated iterations.有限元热分析的陶瓷离合器1 引言磨料空转车辆离合器是力封闭联轴器。

附录 AClutch between engine and transmission installed in the car to travel from the start the whole process, often need to use the clutch. Its role is to make the engine and transmission can be gradually between the joint, thus ensuring a smooth start car; temporarily cut off the link between the engine and transmission to shift at the time of shift and reduce the impact; When the car when emergency braking from Separate role in preventing the transmission and other drive system overload, play a protective role.Clutch similar to the switch, splice or break away from the power transmission and, accordingly, have any form of auto clutch, but the form is different.By the friction plate clutch, springs, pressure plate and the power output shaft composed, arranged between the engine and gearbox, the engine flywheel to the torque is passed to the stored transmission, to ensure that vehicles in different driving conditions passed to the driver Wheel driving force and the right amount of torque, is the scope of the powertrain. In the half-time of linkage, clutch and power input power output allowed speed difference, that is, the speed error to achieve through its transfer an appropriate amount of power. Clutch is divided into three work status, ie the clutch all connections, some of the half clutch linkage and the clutch is not linked.When a vehicle in normal driving, the pressure plate is jammed against the friction plate on the flywheel, pressure plate and friction plate at this time the friction between the largest between the input shaft and output shaft remained relatively static friction, both the same speed . When the vehicle is started, the driver depresses the clutch, clutch pedal movement by pulling back pressure plate, which is the separation of the pressure plate and friction disc, pressure plate and flywheel at this time no contact, but also the relative friction does not exist. Last one, that is, half of the clutch linkage status. At this point, the pressure plate and friction disc friction less than the full-linked state. Clutch pressure plate and flywheel friction plate on the sliding friction between the state. Flywheel speed is greater than the output shaft speed, transmission out of the power from the flywheel to the transmission part of the pass. Between the engine and driving wheels at this time is equivalent to a soft connection status.In general, the clutch and the shift in the vehicle when starting to play a role, this time a transmission shaft and the speed difference between the two shafts, engine power must be cut with a shaft after the synchronizer can be very good a shaft speed will be kept synchronized with the second axis, gear hanging up after, and then through the clutch shaft and the engine power will be a combination of the power continue to be transmitted. In the clutch, there is an essential buffer device, which consists of two similar to the flywheel with the disc, the disc hit a rectangular groove, the groove arrangement of the spring, in the face of fierce shock between the two disc springs between the elastic effect, buffer external stimuli. Effective protection of the engine and clutch. Various parts of the clutch, pressure plate spring strength, friction coefficient of friction plate, clutch diameter, location, and the clutch friction disc clutch performance is to determine the number of key factors, the greater the stiffness of the spring, the higher the friction coefficient of friction plates, the larger the diameter of the clutch, clutch performance, the better.附录 B离合器安装在发动机与变速器之间，汽车从启动到行驶的整个过程中，经常需要使用离合器。

附录How Clutches WorkIf you drive a manual transmission car, you may be surprised to find out that it has more than one clutch. And it turns out that folks with automatic transmission cars have clutches, too. In fact, there are clutches in many things you probably see or use every day: Many cordless drills have a clutch, chain saws have a centrifugal clutch and even some yo-yos have a clutch.CIn!cp I山g?e CgIIeL入D!g?Lg山 o\ cgL 2poM!u? cIn!cp Iocg!!ou. eee 山oLe cIn!cp !山g?e2In this article, you'll learn why you need a clutch, how the clutch in your car works and find out some interesting, and perhaps surprising, places where clutches can be found. Clutches are useful in devices that have two rotating shafts. In these devices, one of the shafts is typically driven by a motor or pulley, and the other shaft drives another device. In a drill, for instance, one shaft is driven by a motor and the other drives a drill chuck. The clutch connects the two shafts so that they can either be locked together and spin at the same speed,or be decoupled and spin at different speeds.In a car,you need a clutch because the engine spins all the time,but the car's wheels do not. In order for a car to stop without killing the engine, the wheels need to be disconnectedf rom the engine somehow. The clutch allows us to smoothly engage a spinning engine to a non-spinning transmission by controlling the slippage between them.To understand how a clutch works, it helps to know a little bit about friction, which is a measure of how hard it is to slide one object over another. Friction is caused by the peaks and valleys that are part of every surface -- even very smooth surfaces still have microscopic peaks and valleys. The larger these peaks and valleys are, the harder it is to slide the object. You can learn more about friction in How Brakes Work.A clutch works because of friction between a clutch plate and a flywheel. We'll look at how these parts work together in the next section.Fly Wheels,Clutch Plates and FrictionIn a car’s clutch, a flywheel connects to the engine, and a clutch plate connects to the transmission. You can see what this looks like in the figure below.When your foot is off the pedal, the springs push the pressure plate against the clutch disc, which in turn presses against the flywheel. This locks the engine to the transmission input shaft, causing them to spin at the same speed.Pressure plateThe amount of force the clutch can hold depends on the friction between the clutch plate and the flywheel, and how much force the spring puts on the pressure plate. The friction force in the clutch works just like the blocks described in the friction section of How Brakes Work, except that the spring presses on the clutch plate instead of weight pressing the block into the ground.W h en the clutch pedal is pressed, a cable or hydraulic piston pushes on the release fork, which presses the throw-out bearing against the middle of the diaphragm spring. As the middle of the diaphragm spring is pushed in, a series of pins near the outside of the spring causes the spring to pull the pressure plate away from the clutch disc (see below). This r eleases the clutch from the spinning engine.Common ProblemsFrom the 1950s to the 1970s, you could count on getting between 50,000 and 70,000 miles from your car's clutch. Clutches can now last for more than 80,000 miles if you use them gently and maintain them well. If not cared for, clutches can start to break down at 35,000 miles. Trucks that are consistently overloaded or that frequently tow heavy loads can also have problems with relatively new clutches.Photo courtesy Carolina MustangClutch plateThe clutch only wears while the clutch disc and the flywheel are spinning at different speeds. When they are locked together, the friction material is held tightly against the flywheel, and they spin in sync. It's only when the clutch disc is slipping against the flywheel that wearing occurs. So, if you are the type of driver who slips the clutch a lot, you'll wear out your clutch a lot faster.Sometimes the problem is not with slipping, but with sticking. If your clutch won't release properly, it will continue to turn the input shaft. This can cause grinding, or completely p revent your car from going into gear. Some common reasons a clutch may stick are: Broken or stretched clutch cable - The cable needs the right amount of tension to push and pull effectively.Leaky or defective slave and/or master clutch cylinders - Leaks keep the cylinders from building the necessary amount of pressure.Air in the hydraulic line - Air affects the hydraulics by taking up space the fluid needs to build pressure.Misadjusted linkage - When your foot hits the pedal, the linkage transmits the wrong amount of force.Mismatched clutch components - Not all aftermarket parts work with your clutch.depress fully. If you have to press hard on the pedal, there may be something wrong. Sticking or binding in the pedal linkage, cable, cross shaft, or pivot ball are common causes. S o metimes a blockage or worn seals in the hydraulic system can also cause a hard clutch. Another problem associated with clutches is a worn throw-out bearing, sometimes called a clutch release bearing. This bearing applies force to the fingers of the spinning pressure plate to release the clutch.If you hear a rumbling sound when the clutch engages,you might have a problem with the throw-out.Types of ClutchesThere are many other types of clutches in your car and in your garage.An automatic transmission contains several clutches. These clutches engage and disengage various sets of planetary gears. Each clutch is put into motion using pressurized hydraulic fluid. When the pressure drops, springs cause the clutch to release. Evenly spacedridges, called splines, line the inside and outside of the clutch to lock into the gears and the clutch housing. You can read more about these clutches in How Automatic Transmissions Work.An air conditioning, compressor in a car has an electromagnetic clutch. This allows the compressor to shut off even while the engine is running. When current flows through a magnetic coil in the clutch, the clutch engages. As soon as the current stops, such as when you turn off your air conditioning, the clutch disengages.Most cars that have an engine-driven cooling fan have a thermostatically controlled viscous clutch -- the temperature of the fluid actually drives the clutch. This clutch is positioned at the hub of the fan, in the airflow coming through the radiator. This type of clutch is a lot like the viscous coupling sometimes found in all-wheel drive cars. The fluid in the clutch gets thicker as it heats up, causing the fan to spin faster to catch up with the engine rotation. When the car is cold, the fluid in the clutch remains cold and the fan spins s lowly, allowing the engine to quickly warm up to its proper operating temperature.Many cars have limited slip differentials or viscous couplings, both of which use clutches to help increase traction. When your car turns, one wheel spins faster than the other, which makes the car hard to handle. The slip differential makes up for that with the help of its clutch. When one wheel spins faster than the others, the clutch engages to slow it down and match the other three. Driving over puddles of water or patches of ice can also spin your wheels. You can learn more about differentials and viscous couplings in How Differentials Work.Gas-powered chain saws and weed eaters have centrifugal clutches, so that the chains or strings can stop spinning without you having to turn off the engine. These clutches work automatically through the use of centrifugal force. The input is connected to the engine crankshaft. The output can drive a chain, belt or shaft. As the rotations per minute increase, w eighted arms swing out and force the clutch to engage. Centrifugal clutches are also often found in lawn mowers, go-karts, mopeds and mini-bikes. Even some yo-yos are m anufactured with centrifugal clutches.C lu tches are valuable and necessary to a number of applications. For more information on clutches and related topics, check out the links on the following page.离合器工作原理如果您驾驶手动变速箱的汽车，您可能会惊讶地发现，它有一个以上的离合器。

附 录录1Clutch of new developments in technologyAbstract: in recent years car design and manufacturing technology progress for all to see. In order to further improve product performance, prolong service life, common mechanical clutch technology is also produced a remarkable change. No matter from structural characteristics, product process performance, or control technology, mechanical clutch of technological progress in some extent reflects the development of design concepts, and possible technology trends in the future.Keywords: clutch; Technology development1, introductionIn car technology rapid development today, especially with the electronic technology in cars, the extensive application of vehicle drivetrain is had great progress, as an important part of the transmission of the clutch assembly force transmission, the burden of reducing vibration and prevent system overload very important role. To make sure that the power transmission and reliable, separate thoroughly, combined with soft, damping good, small volume, light weight, easy, long service life, making the clutch product either cash from the performance, structure, or manufacturing mode and control, in the occurrence of a lot of change. They greatly optimized clutch all aspects of performance, to some extent look, these changes are also reflected the development direction of the clutch.2, engine flywheel new structureAs one of the flywheel storage components engine, is also part of the clutch initiative. As the car transmission belong to multi-freedom torsional vibration system, whether the incentive and transmission system, or the associated force vibration type and the coupling vibration with other statements are very complex. In order to adapt to car driving conditions of vibration and noise reduction of reducing the need, making cars, ride comfort the role of torsional shock absorber is extremely important. It should be able to adjust the system inherent frequency, the system mainly low-order resonance critical speed remove common, also need to use speed range, still need to decrease amplitude damping of transmission system can reduce idle noise, ease the impact of the special case load. Previous clutch platen set on by a twist of shock absorber, decorate a space place is restricted, shock absorber work reverse Angle small, torsion stiffness big, capacity small, springs, and therefore not guarantee the intensity of vibration reduction is limited.In recent years, the emergence of a reverse damping characteristics and performance to price are ideal double quality flywheel structure. The flywheel by primary flywheel, reverse shock absorber and subprime flywheel composition, among them, the primary flywheel on one hand we should provide for the shock absorber and clutch installation space, on theother hand also with appropriate rotational inertia insure a car, and reduce passed back starting the amplitude. Generally, double quality flywheel adopts with circular arc shape along the spiral spring primary flywheel outer periphery decorate way, in limited circumstances decorate a space, the arrangement to obtain larger primary flywheel rotational inertia. The inertia and the clutch after brief increase engine speed fluctuation of related parts, shorten their service life. To avoid the above phenomenon, often need additional Settings special damping, such, can increase the difficulty and cost of product development. Because the engine of the car front front drive type of transmission installation space is limited, so this kind of structure in FF type cars to the promotion. Meanwhile, this kind of decorate spring along the circumference, due to high speed double quality flywheel centrifugal role, spring wear when, or even produces broken.Using radial layout springs can improve the double quality flywheel of the above mentioned products defect. It consists of primary flywheel, 3 ~ 4 springs box, damping dish and subprime flywheel composition. Because the suspension spring box of radial layout, the primary flywheel rely on four posts the muscles of rib takes form enough flywheel stiffness and produced similar with traditional flywheel inertia.This kind is decorated in a small space to with smaller quality to gain the maximum rotation inertia, help reduce the assembly structure, the axial dimensions for subprime flywheel and clutch decorate a space make more. Its damping device by a wear-resisting plastic gasket, a belt of steel plate and a slot disc spring washers constitute, they set in damping plate, rely on damping disc hole flanging positioning and compaction, the damping disk with primary flywheel riveted by the subprime, plastic gasket flywheel slot drive. Practice proves that the double quality than ever, this structure can be the flywheel in a limited space get quite good vibration reduction.Engine for the job, usually by the flywheel, inertia and the clutch clutch disc provides together. The ideal flywheel structure should be to offer the same, and ensure enough inertia structure stiffness premise to minimize the flywheel quality, stamping steel way to replace traditional casting can obtain the flywheel ways to produce the effect. Change the pressure by casting lron yuntechtc ring, start toothed ring and steel blunt system drivers disk of three parts. In the ring gear driving plate welding, pressure rings and drivers disk riveting, pressure ring of moment of inertia of the subject constitutes a flywheel, and provide for the clutch friction surface and heat conduction. Drivers disk improve enough flywheel stiffness, and using laser welding and clutch cover, this is connected to this structure forms of changescan be compared to traditional iron flywheel reduce quality 5% ~ 10%. USES the steel plate stamping type flywheel, and clutch cover and flywheel connections between after replacing bolt connection with welding, reducing the number and machinery manufactured parts, which reduces the production cost. The foregoing radial layout springs double quality can use this stamping yuntechtc for structure form, reducing axial dimensions []17. 3, clutch discClutch platen design of the main contradiction is facing, on one hand, hope to have as played platen diameter, in order to obtain the good preach torsional characteristic, reducing friction slices wear quantity and improve the service life, on the other hand, hope the decrease of the platen as possible, so as to shorten the rotational inertia of the variable transmission shift, ensure the synchronization time of smooth, transmission clutch platen ontology conscious drops, and therefore made wavy often difficult to coordinate the contradiction. When using triangle groove platen ontology structure, while keeping the original way wavy platen ontology has the axial elastic properties at the same time, because of its large on the plane can be formed, enough to make its and friction slices adhesive is used to connect the replacement of traditional riveting, so that in friction chip will not need the thickness of the steel back to reserve rivet, so clutch friction slices thickness, which can reduce the platen axial dimensions, and can be reduced by 10% of inertia can reduce nearly 25%. In other words, keep the premise of inertia unchanged, possible will platen diameter increases, so can the arrangement for torsional shock absorber, let a space when damper spring job increase, the rigidity of the shock absorber in diameter can be reduced greatly, increasing the space for setting also provides an ideal damping components fundamental conditions. On the other hand, because platen diameter increases, the optimization of diaphragm spring separation means it can obviously reduce leverage than the load bearing separation.Using triangle groove platen ontology and friction piece of adhesive technology, still can make clutch friction slices surface pressure distribution, and more uniform can improve the service life of friction slices.4, clutch diaphragm springUsing the diaphragm spring of a nonlinear elastic properties, can increase the ability of clutch abrasion resistance. Usually, can pass the clutch when installation, adjustment diaphragm spring axial position, to keep the spring of compaction force, but due to the manufacturing process of previous position error is quite large, so often wasted spring this portion of elastic energy, enables the abrasion resistance ability get full play. When the clutch cover and flywheel connection with the above welding way to finish, the clutch assembly may allow such position when the adjustment, thus, the corresponding clutchscratch-resistant ability can improve the 4% ~ 30%.To improve the ability to change its antiwear properties, but also can the diaphragm spring is reinforced by controlling method of separation means and the rib disc supporting ring approach to getting.[]175, clutch control systemAutomatic transmission in cars growing popularity of today, due to its lack of transmission efficiency of cars, and motorists feel lost control, makes mechanical clutch still has wide market. Along with the computer technology and the rapid development of modern control technology has to clutch may reality automatic control, automatic clutch management system (CMC) is the product of this idea. The driver speaking, clutch automatic control system is that it is the most obvious advantage of cancelled the clutch pedal, thus improve the driving comfort, whether in the city the frequent change of traffic environment, or in the ramp, its advantages are started is quite clear. Meanwhile, in order to reduce the transmission low noise and vibration, CMC is likely to clutch real-time control of sliding, all these can improve automobile driving safety. Although the automatic transmission can also play the same role in price, but the CMC, fuel efficiency, engine braking and rapid response, etc but again the obvious advantage. In addition, it has no peristalsis phenomenon, and can make control shift timing. Drivers On the other hand, for car itself, because the CMC reduced because the actual driving quite frequent false operation produces drivetrain stress, therefore, can reduce the transmission and its transmission parts design dimensions, in general driving conditions, electronic control ensures the accuracy and speed than artificially operation circumstance clutch of wear small, long service life.CMC consists of three parts: namely is used to identify the driver intention and the clutch, the transmission working state of sensors,Clutch actuators and electronic control unit, drivers shift HuanDangGan movements and intention through the release of the accelerator pedal to identify, this requires signal judge strategy and control must be very quick, to avoid the feeling of driver produce shift block, when pilots inadvertently tinkering with the transmission system when rod may not false action. In addition, the CMC through the engine speed, the transmission input shaft speed and throttle position signal to clutch slip for mind control, which can eliminate the car driving common vibration and noise. Such as a limit control to prevent slip in 1 and 2, block small throttle low-speed driving, the car slightly tilted forward, generating about 1Hz very uncomfortable zitterbewegung, through in the clutch of transient torsional direction change quickly, to eliminate the separation clutch in clutch under the condition of incomplete combinations, when pilots alternate relaxation and trample accelerator pedal, because thetransmission torque change to the sharp produced recoiling sickening crash; or depressing Through the precise relative slip between 50 ~ 100rpm control, can eliminate in high-grade, high and low speed conditions when the engine driving torque values in the passenger cabin can smell the low-frequency resonance produced, and when the transmission in 2 ~ 3 block,engine speed 12 ~ 2500rpm and high load, the transmission possible beats noise; Through the separation clutch, convenient when the elimination of the idle will clutch and neutral transmission combine, engine torque peak in the transmission of idle speed noise produced. The key is to prevent vibration noise sensitivity and accuracy, this system requirements system has high control ability, rely on modern computer and hydraulic control technology has been possible this some.[]186, closingBy adopting a new design concept, can make clutch axial dimensions is much shorter, platen diameter increases, power transmission more reliable, clutch capacity increases, separation bearing load is reduced, torsion vibration reduction improve, processing manufacturing easier, lower cost, service life can be extended 50% and than before can be expected, along with the automatic control technology mature gradually perfect, clutch control mode will also continue to rapid development.附 录录 2汽车离合器技术的新发展摘要：近年来汽车设计和制造技术的进步有目共睹。

附录A Little Brief Introduction Of ClutchNowadays the pioneers of the clutch disc, clutch disc is more pieces of it until 1925 later. The multi-gear clutch main advantage is that car started the clutch engagement is no impact on the smooth. Early in the design, layout design, according to slice pairs of a steel plate with a bronze blanks. Using the friction pair of pure metal, put them in oil, can achieve more satisfactory performance.As the power to combustion in mechanical transmission automobiles, clutch is as an independent assembly. The clutch is usually served in the engine and transmission, the active part between connected with engine flywheel, driven and transmission. Various types of cars for widespread adoption of friction clutch, in fact, is a kind of depend on their part, driven to relay the friction between the power and the separation. The major function of the clutch is cut off and the realization of the engine and transmission, to ensure smooth, stable car When the shift in the engine and transmission of separation, reduce transmission gear shift between the impact, Work in the dynamic load is larger, can limit the transmission of maximum torque, in order to prevent the transmission parts of a damaged by overload, Reducing effectively the transmission of the vibration and noise.In the early development of clutch structures, the most successful conical clutch. It was the prototype design in 1889 German Daimler company production of steel wheel on the car. It is to make the engine flywheel hole taper as clutch active. The taper clutch scheme continues to the middle of the twentieth century, when the manufacture, cone-shaped clutch friction relatively simple, easy to repair. It was used LuoMao friction material, leather belt, etc. Then have been hoof - drum clutch, its structure in the solid-bowl clingy reaches hoof. Hoof - drum clutch friction components with wood, leather belt is such, shoe - drum clutch weight is light cone clutch. Whatever tapered clutch or hoof - drum clutch, easy to cause the separation is not complete appear even Lord, follower cannot separate self-locking phenomenon.Years of practical experience and technical improvement makes people tend to preferred dry friction clutch single chip, because it has driven part of inertia, good heat, simple structure, convenient adjustment, compact size, etc, but also because completely in structure, already cantake action to smooth, so now junction disc is widely used in large, medium and small various models.Now monolithic dry type clutch in structural design is quite perfect. Using the axial elastic platen, improve the clutch of comfort. The clutch platen assembly installed in reverse, prevent the transmission system of shock of torsional resonances, reduced the transmission system of noise and load.As the car comfort requirements, clutch in original basis has been obtained by car, by continuously improved by increasing the quality of the flywheel has double shock absorber, can turn better reduce transmission noise.Due to heavy clutch, commercial, engine power tends to large-scale increasing, but the size of the space increased clutch allows the use of limited, clutch, cool, increase conditions to improve ability, preaching clutch torsion life-span, simplify the operation has become the development trend of the heavy clutch. In order to improve the ability of torsion, in heavy vehicles can be used on double dry type clutch. Theoretically, in the same radial dimensions, biplate clutch torsion ability and the service life is 2 times of single chip. But other objective factors, the actual effects of low value than others.In recent years, the wet clutch on technology improvement, some heavy cart in abroad and start using multiple wet clutch. Compared with dry type clutch, due to the use of the pump are forced cooling, friction surface temperature is lower than 93 degrees Celsius (not), therefore, long time also does not start sliding friction loss. Refer to the information at home and abroad were told that this clutch can use dry type clutch of 5-6 times, but the advantages of the wet clutch play must be in a temperature range, more than it can achieve a temperature range will play a negative effects. Now this technology is not perfect.一些离合器的简介现今所用的盘式离合器的先驱是多片盘式离合器，它是直到1925年以后才出现的。

毕业设计（论文）英文翻译、年级、专业: 2008级机械设计制造及其自动化姓名:张春友学号: 312008*********指导教师:孙书民徐红The design of diaphragm springAbstractThe clutch is the important components in automobile transmission system, the main function is to achieve is cut off and the engine to the power transmission, guaranteed that the automobile starts smoothly, ensure drive system when the shift work smoothly and limit the transmission system to withstand the maximum torque, prevent the transmission system overload. Diaphragm spring clutch is in recent years in the vehicle and light vehicle used in a clutch, the torque capacity of large and relatively stable, convenient operation, good balance, can be mass production, and the research on it has become more and more important.Keywords: diaphragm spring clutch;Diaphragm spring clutch overviewDiaphragm spring clutch is in recent years in the car and light truck used a clutch. Because of its as a pressure spring, can also play the separation lever effect, whereby the clutch in order to simplify the structure, quality reduction, and remarkably reduce the axial size of clutch. Secondly, as a result of diaphragm spring and pressure with the circumferential contact, so that uniform distribution of pressure. In addition due to the diaphragm spring with nonlinear elastic properties, it can be in the driven disc friction plate abrasion, spring can still reliably transfer the torque of the engine, without causing slip away from. Clutch, the clutch pedal manipulation of light, reduce the labor intensity of the driver. In addition, because of the diaphragm is a symmetric parts, good balance, at high speed, the pressing force reducing rarely, but the week arranged elastic clutch at high speed, due to the centrifugal force will generate transverse bending, spring severe drum, thereby reducing the pressure plate pressure, thereby causing the clutch to transmit torque capacity. As can be seen, for light diaphragm spring clutch design research for the improvement of automobile clutch performance in all aspects has very important significance.As the hold-down spring called diaphragm spring, is made of spring steel stamped, with" no bottom plate" shape of the truncated cone shaped thin wall diaphragm, and the small end surface on a plurality of radial groove, to form an elastic lever, while the remaining slots cut end truncated conical part is a spring action. Diaphragm spring are arranged on the both sides of the supporting ring, and the latter by means of a fixed on a clutch cover some ( radial grooves cut in half number of rivets to install location ). When the clutch cover bolt fixed to the flywheel, the flywheel clutch cover to the rear support ring, diaphragm spring to generate elastic deformation, the apex angle of the cone becomes large, and evenalmost flattened diaphragm spring. At the same time the larger end of the diaphragm spring pressure plate pressing force generated on the clutch is in the coupling. When the clutch is disengaged, the separation bearing forward diaphragm spring pressure before the supporting ring as a fulcrum of reverse tapered transition, so that the diaphragm spring after the shift, and by separating the hook pulling the pressure shift clutch. Diaphragm spring clutch has many advantages: first of all, as a result of the diaphragm spring with nonlinear characteristic, therefore the design of the friction plate abrasion, spring pressure is nearly constant, and can reduce the separation when the clutch pedal force, make the manipulation of light; secondly, diaphragm spring clutch mounted position on the center line of the shaft are symmetrical, so the pressing force actually from the influence of the centrifugal force, stable performance, balance or; furthermore, diaphragm spring itself and pressing spring and separation of the clutch lever effect, simple structure, less number of parts, the quality decreases obviously shortens the axial dimension; in addition, the diaphragm spring and the pressure plate is the entire circumferential contact, so that the pressure uniform distribution, good contact friction friction plate, uniform, easy to achieve good ventilation and cooling.Pull type diaphragm spring clutch has the advantagesCompared with push, pull type diaphragm spring clutch has many advantages: a middle supporting components, and do not support ring or only a supporting ring, the structure is simple, compact structure, fewer parts, quality less; pull type diaphragm spring is central and the platen press platen size in the same conditions the larger diameter diaphragm spring, improves the pressing force and the ability to transfer torque, and does not increase the pedal force, in the transmission of the same torque, can use the small size structure; in the joint or separate state, the clutch cover deformation small, large stiffness, higher separation efficiency; pull leverage ratio greater than push-down lever ratio, and the intermediate support to reduce the friction loss, high transmission efficiency, pedal operated more portable, pull type pedal force than the push type general reduction; both in the joint state or separate state, pull type diaphragm spring clutch structure with cover support keeping in contact, on a supporting ring wear can not be formed after clearance and increased pedal free travel, no impact and cry; a longer service life.Clutch diaphragm spring designThe structural characteristics of diaphragm springFrom the front can know, the design of the diaphragm spring compression spring is. The diaphragm spring clutch push and pull, in the design of the structure. Diaphragm spring in the shape of the structure is divided into two parts. In the larger end of the diaphragm spring is an integrity of the frustum, it is shaped like a bottomless dishes and general machinery with disc spring disc spring are exactly the same, so as part of. Diaphragm spring on elastic effect is the dish spring part. Disc spring elastic effect is that: along the axial direction of loading, disc spring compression becomes flat, after unloading and the restoration of the prototype of the.Can be said that the diaphragm spring disc spring is a special structural form. The difference is, the diaphragm spring is also arranged on the radial slotted section. On the diaphragm spring radially slotted portions like a ring of petals, its role is, when the clutch is disengaged as separation lever. So it is also called the separation claw. Separation claw and a disk spring component junction radial slot wide rectangular circular hole. In so doing, one can reduce the stress concentration at the root of the separation claw, on one hand and can be used for the placement of pins fixed diaphragm spring, separation claw root fillet transition R > 4.5.Diaphragm spring deformation and loading methodAs a result of diaphragm spring used to push type structure, so the dress. In the engagement and disengagement of clutch, diaphragm spring loading situation is different, corresponding to two modes of loading and deformation:(1): when engaging clutch diaphragm spring up, pressing spring, the pressure plate in -- clutch cover assembly and flywheel assembly previously, diaphragm spring approximation is in free state, diaphragm spring on the platen without compressing function. When the platen -- clutch cover assembly and flywheel mounted together, the front end of the flywheel clutch cover to the front end surface close. Therefore, the clutch cover through the supporting ring 4of the diaphragm spring loaded, almost flat diaphragm spring. At the same time on the platen also effect of load. We call the pressing force. The supporting ring 4and a diaphragm spring plate contact between the height variation called big deformation of diaphragm spring release bearing, relative to the platen height variation called the small end deformation. (2): when the separation bearing separation with P2force acting on the diaphragm spring of the small end, a supporting ring 4is inoperative, and the supporting ring 5to play a role in. When the P2force reaches a certain value, diaphragm spring is pressed over. Separation in the larger end of the diaphragm spring and the small end will further generate additional deformation and. The diaphragm spring deformation of 。

外文资料翻译THE RESEARCH AND DESIGN USING CAD SYSTEM FOR THE CLUTCH OF AUTOMOBILEClutch is used to transfer and switch of the powers which are coming from the engine. In automobile, clutch is connected with engine and derailleur. It can shut of and stably transfer the power between them. How to reasonably, efectively and speedily design clutch always is the pursuing destination of all clutch factories. The appearance of CAD which is the abbreviation of computer aided design make it possible. Automobile CAD is the forerunner of CAD all the times. CAD is fist used in automotive industry and become more and more indivisible with CAM, CAE and CAP furthermore, integration is becoming to reality. Researching how to use computer to aid us design the automobile clutch and how to develop a useful and advanced automobile clutch computer aided design system-abbreviation is ACCAD that can make a steady system framework for automobile cultch integrated design and manufacture system. are the destination of this thesis.ACCAD system should firstly be able to aid engineer design clutch, secondly to aid engineer analyze the designed clutch, finally to organize and manage the data of design. From the long-term consideration it should also be able to aid workshop manufacture clutch and help manager supervise all the lifecycle of clutch. So it should have a core which can integrate all these subsystem. Engineering database (EDB) is just for this use and Using EDB to construct CIMS become an inevitable current. In order to expand ACCAD and realize clutch CIMS in the future ACCAD system also need EDB as the core to integrate each design and management subsystem into a whole system. At the third chapter of this thesis the technology of EDB and how to design automobile clutch EDB are researched and automobile clutch EDB is set up according to the framework of entire database, project database and design database.The traditional procedures of the design of automobile clutch are: selecting storing coeficient, designing clutch structure type, friction flat, clutch sketch, assembled module and each part of clutch. In our country, all these procedure are handmade, but in the coming years with the application of computer aided drawing software such as AutoCAD of AutoDesk corp. engineering drawing can basically be done by computer. But the depicting capability of this two-dimension engineering drawing module is so deficient that it can only be used as drawings and can't be used to analyze by computer. Along with the appearance of B-P modeling and curve-based or solid-based modeling, mechanic parts are denoted by three-dimension module which can beter aid engineer design and analyze them. But this module loses parts of the whole information of them, so it results in much dificulty to integrate aided design subsystem, aided manufacture subsystem and computer analyzing subsystem. Feature-based modeling can just make up this shortcoming, and also if it combines with parameter design technology it can enhance the capability not only of depicting but also of fast amending. At the forth chapter of this thesis the technology of feature-based is researched and the parametric feature-based solid models are created upon MDT that is belonging to AutoDesk corporation.In order to aided engineers to design clutch faster computer is used to simulate engineers to use variant design technology to design clutch products that are based on original models. Variant design technology has some intelligence. Intelligent CAD is a direction of developing CAD. At the fifth chapter of this thesis the technology of variant design is researched and variant design of automobile clutch is achieved on MDT by the technology of parameter table-driven and feature restrainedBesides some degree of integrity and intelligence ACCAD system should have some degree of automation, that is to say that ACCAD can automatically design clutch according to primitive design requests, analyze, check and optimize some basic parameters of clutch. At the sixth chapter of this thesis the combining model of clutch is analyzed, some formulas of designing and calculating basic parameter are deduced, the working instances of diaphragmspring are analyzed and the characters of load-distortion and stress-strain are calculated simulatively by the formulas of A-L which are approbatory internationally nowadays. The optimizations of some basic parameters and diaphragm spring are carried out by multi-body arithmetic in which design destinations, design restrictions and the primitive value of design variables can be changed according to real demands. Instances deduction and design templates are used to design the model of each part of clutch and all these models are assembled automatically after that basic parameters and structure type are completed according to primitive design demands. The design templates are deduced in existing design instance of clutch product by inteligent instance-deducing technology. Then designers can mend and to-and-fro design them till they can meet the design demands. So computer aided function and man's initiative can be fully enlarged, automatic design and mutual design are combined indeed .It needs not only much knowledge of automobile clutch design and CAD but also much high lever of software design and computer application to really realize such a complicate and advanced ACCAD system. So I also researched the method of object-oriented and the operation system of Windows and study many sorts of program design language. The theory of software engineering is used to analyze ACCAD system in requirement, function structure, flow chart, project design and module design. The software developing tools of Visual Basic and Visual C++ are used to design and implement the ACCAD system. Yi-Dong clutch corporation have applied it to design clutch. Practice proves that the ACCAD system can aid designers to design clutch well, remarkably improve the ability of clutch product design, greatly shorten the design cycle and also it has very high stability and extensibility.INVESTIGATION TO DYNAMICS AND CONTROL OFVEHICLE AMT CLUTCHES DURING ENGAGEMENTChina Automotive Parts enterprises face more and more pressure and challenge with China joining WTO.The global Automotive and Parts MNC are gradually entering the lastly and largest potential market of the world.The local automotive industry especially parts is not so good as MNC no matter in scale, capital capacity, products technical level and marketing level.So in order the to exist,the local automotive parts enterprises must improve themselves as quickly as possible in some the fields. One of the important reasons for this risk is the slow Product Engineering with low technical content.It is caused by several reasons that are outdated engineering method，insufficient working experiences，low quality of the working people and the outdated methodology of product Engineering，and the last one is the most important reason.In comparison with hydraulic Automatic Transmission (AT) and Continuously Variable Transmission (CVT), Automatic Mechanical Transmission (AMT) has advantages of much lower cost in manufacturing and easier installation in driveline system .This means that there exists a vast potential market for development of such a mechatronical technology. As an important functional module in AMT vehicles, however, the automatic clutches developed by far still have some shortcomings, for example, of road startup failure, considerable shock, unstable shifting, friction-caused service life reduction, and time-delay response. The key concern is therefore concentrated in this dissertation on real implementation of optimal transient responses and control laws during engagement of the clutches, and detailed investigations are made both in theory and experiment.Strong nonlinearities exist in such component systems as engine, clutch membrane spring and servo actuator and consequently dificulties are encountered in design of the optimal control for improving transient responses of the automatic clutch. A system synthesis is proposed herein for the study of nonlinear dynamics and control of AMT automatic clutches. Based on principles of automotive powertrain systems, the main system under consideration can be decomposed into two sub-systems, engine and transmission systems. The Popov super stability theory has adopted for the first time in association with reference,model following adaptive control for the engine. monitoring. The engine monitor requires accurate predictions of rational velocities. A prediction model is constructed on the basis of flat neural network A fast recursive algorithm is used to improve the learning speed by forgetting factor. Accordingly, the present neural network algorithm leads to considerable reduction of efort in network weighting matrix as wel as increase of self-learning and adaptability of neural network algorithms to nonlinear and nonstationary systems. It has been shown by comparison of the numerical results with experiments that the modified algorithm is proved to be reliable and efective in the engine condition monitoring. In modeling the system, the load-deflection relationship of the clutch membrane spring is generally treated as a black box, and as a result many advanced control methods can not be applied. A new approach for the black box is required nevertheless in development of the accurate model. The nonlinear relationship is mathematically derived out for the clutch system during engagement and a further progress is thus made to certain extent for the Almen-Lazslo method. By matching control inputs of the two subsystems, a synthetically optimal performance of the system can be achieved. It can be seen that by the system synthesis, not only the design of a feedback controller is accommodated according to longitudinal dynamic requirements of the whole vehicle, but an efective procedure is established for solving problems of time-delay and inaccuracy due to the use of the analysis method of upper-lower layers.Diferential geometry provides a powerful tool for the analysis of nonlinear dynamic systems. With consideration of the automatic clutch which is a typical afine nonlinear system, the diferential manifold and corresponding a companion form to the original system with nonlinearities can be constructed by using feedback linearization approach. It is demonstrated by simulations and experiments that this method simplifies the design of the controller, and is of practical significance for real engineering applications. In this dissertation, ∮operator and its transform in frequency domain are introduced for the first time into the field of automotive electronics technology. In comparison with the conventional z operator, digital iterations of ∮operator are featured by higherprecision and more stability while sample time T -4 0.The nonlinear sliding mode controller is taken as an example, the implementation form of ∮operator discretization control, the error analysis and the algorithms stability are studied both theoty and engineering application. In high frequency sampling systems the approach has advantages in industrial applications and enriches its new fields of application, especially in vehicle eletronics.Based upon the minimum value principle, a multi-objective optimal control is applied to derive out for the first time the optimal response in analytical form by compromising longitudinal shock and plane slipage of the automatic clutch related with each other in the transmission sub-systems. The real significance of the synthetic optimal control lies in expression of the theoretical optimal performance. For preventing the control system from system uncertainties and external perturbations the robust sliding mode controller is designed to guarantee the system to trace the optimal trajectory. Since dynamic properties of the sliding mode is invariant to extraneous disturbance, the SMC method may apply fora kind of complicated systems with nonlinearities and uncertainties like the automatic clutch. It is shown through numerical simulations that errors of the SMC in reference model following are far less than the PID controler whenever the damping orifice flux coeficient of an on-of solenoid, the frictional plate wear qualilty, friction coeficient and the driveline elastic coeficient may be deviated in a permissible range, respectively. Hence, the present work possesses of significant value in engineering application.As an important part of the dissertation, the virtual mechanical prototyping and real on-vehicle experiments for the automatic clutch system are made, respectively. The virtual machine is modeled in ADAMS software and verified by real vehicle experiments. Therefore, through comparison of the virtual experiments within ADAMS environment with theoretical predictions for transient responses of the clutch during engagement, reliable and efective instructions are provided for design of the hydraulic actuator and PC controller required in real vehicle experiments. The control apparatus for automatic clutch include sensors, microcomputer and their interfaces. All experiments are carriedout on the Santana LX car, and much atention is focused to typical dificult working conditions, such as small throtle angle, heavy load, high gear and steep ramp. It is shown by the results obtained from the experiments that fairly good transient responses during the clutch engagement are achieved. By the control strategies presented in this dissertation, the engine is prevented from flameout, moreover, vehicle startup and gear shift smoothly can be adjusted with short friction duration and quick response of the actuator. All these mean that the adaptability for subjective will, time varying driving conditions of vehicle and complicated surroundings. In a word, on the basic of theoretical research and control technology, the performance of AMT automatic clutch is improved markedly, moreover, the apparatus for experiments establishes a massy foundation for future product development.。