车辆工程外文翻译---汽车悬架如何工作

外文文献（二）外文原文Abstract：To improve the suspension performance and steering stability of light vehicles, we built a kinematic simulation model of a whole independent double-wishbone suspension system by using ADAMS software, created random excitations of the test platforms of respectively the left and the right wheels according to actual running conditions of a vehicle, and explored the changing patterns of the kinematic characteristic parameters in the process of suspension motion. The irrationality of the suspension guiding mechanism design was pointed out through simulation and analysis, and the existent problems of the guiding mechanism were optimized and calculated. The results show that all the front-wheel alignment parameters, including the camber, the toe, the caster and the inclination, only slightly change within corresponding allowable ranges in design before and after optimization. The optimization reduces the variation of the wheel-center distance from 47.01 mm to a change of 8.28 mm within the allowable range of -10 mm to 10 mm, promising an improvement of the vehicle steering stability. The optimization also confines the front-wheel sideways slippage to a much smaller change of 2.23 mm; this helps to greatly reduce the wear of tires and assure the straight running stability of the vehicle. Keywords：vehicle suspension; vehicle steering; riding qualities; independent double-wishbone suspension; kinematic characteristic parameter; wheel-center distance; front-wheel sideways slippage1 IntroductionThe function of a suspension system in a vehicle is to transmit all forces and moments exerted on the wheels to the girder frame of the vehicle, smooth the impact passing from the road surface to the vehicle body and damp the impact-caused vibration of the load carrying system. There are many different structures of vehicle suspension, of which the independent double-wishbone suspension is most extensively used. An independent double-wishbone suspension system is usually a group of space RSSR (revolute joint - spherical joint -spherical joint - revolute joint) four-bar linkage mechanisms. Its kinematic relations are complicated, its kinematic visualization is poor, and performance analysis is very difficult. Thus, rational settings of the position parameters of the guiding mechanism are crucial to assuring good performance of the independent double-wishbone suspension. The kinematic characteristics of suspension directly influence the service performance of the vehicle, especially steering stability, ride comfort, turning ease, and tire life.In this paper, we used ADAMS software to build a kinematic analysis model of an independent double-wishbone suspension, and used the model to calculate and optimize the kinematic characteristic parameters of the suspension mechanism. The optimization results are helpful for improving the kinematic performance of suspension.2 Modeling independent double-wishbone suspensionThe performance of a suspension system is reflected by the changes of wheel alignment parameters when the wheels jump. Those changes should be kept within rational ranges to assure the designed vehicle running performance. Considering the symmetry of the left and right wheels of a vehicle, it is appropriate to study only the left or the right half of the suspension system to understand the entire mechanism, excluding the variation of WCD (wheel center distance). We established a model of the left half of an independent double-wishbone suspension system as shown in Figure 1.3 Kinematic simulation analysis of suspension modelConsidering the maximum jump height of the front wheel, we positioned the drives on the translational joints between the ground and the test platform, and imposed random displacement excitations on the wheels to simulate the operating conditions of a vehicle running on an uneven road surface.The measured road-roughness data of the left and right wheels were converted into the relationship between time and road roughness at a certain vehicle speed. The spline function CUBSPL in ADAMS was used to fit and generate displacement-time history curves of excitation. The simulation results of the suspension system before optimization are illustrated in Figure 2.The camber angle, the toe angle, the caster angle and the inclination angle change only slightly within the corresponding designed ranges with the wheel jumping distance. This indicates an under-steering behavior together with an automatic returnability, good steering stability and safety in a running process. However, WCD decreases from 1 849.97 mm to 1 896.98 mm and FWSS from 16.48 mm to -6.99 mm, showing remarkable variations of 47.01 mm and 23.47 mm, respectively. Changes so large in WCD and FWSS are adverse to the steering ease and straight-running stability, and cause quick wear, thus reducing tire life.For independent suspensions, the variation of WCD causes side deflection of tires and then impairs steering stability through the lateral force input. Especially when the right and the left rolling wheels deviate in the same direction, the WCD-caused lateral forces on the right and the left sides cannot be offset and thus make steering unstable. Therefore, WCD variation should be kept minimum, and is required in suspension design to be within the range from -10 mm to 10 mm when wheels jump. It is obvious that the WCD of non-optimized structure of the suspension system goes beyond this range. The structure needs modifying to suppress FWSS and the change of WCD with the wheel jumping distance.ADMAS software is a strong tool for parameter optimization and analysis. It creates a parameterization model by simulating with different values of model design variables, and then analyzes the parameterization based on the returned simulation results and the final optimization calculation of all parameters. During optimization, the program automatically adjusts design variables to obtain a minimum objective function [8-10]. To reduce tire wear and improve steering stability, the T able 1 V alues of camber angle α , toe angle θ , caster angle γ and inclination angle β before and after optimizationTable 1 The data tables of optimize the results4 ConclusionsThe whole kinematic simulation model of an independent double-wishbone suspension system built by using ADAMS software with the left and the right suspension parts under random excitations can improve the calculation precision by addressing the mutual impacts of kinematic characteristic parameters of the left and the right suspension parts under random excitations. The optimization can overcome the problem of the too large variation of WCD and overly large FWSS with the wheel jumping distance. The kinematic characteristic parameters of the suspension system reach an ideal range, demonstrating that the optimization protocol is feasible. From a practical perspective, the optimization is expected to reduce tire wear, and remarkably improve suspension performance and vehicle steering stability.Figure 1 simple picture of suspensionFigure 2 Curve with the parameters of the suspension译文摘要：为了提高轻型车辆性能和行驶稳定，我们使用ADAMS 软件建立一个独立双横臂悬架系统运动仿真模型，并建立随机激励的测试平台，根据车辆实际运行条件，探讨悬架的运动学特征参数的变化。

Automobile Suspension System汽车悬架系统Automobile suspension systemhas two basic functions, to keep car's wheels in firm contact with the road and to provide comfortable ride form the passengers. A lot of the system's work is done by the spring. Under normal conditions, the springs support the body of the car evenly by compressing and rebounding with every up-and-down movement. This up-and-down movement, however, causes bouncing and swaying after each bump and is very uncomfortable to the passenger.This uncomfortable effects are reduced by the shock absorbers.汽车悬架系统有两个作用:保持汽车车轮与路面的良好接触，提供乘客的乘坐舒适性。

大量的工作是由弹簧来完成的。

在正常情况下，弹簧通过压缩和伸张均匀地支撑着车身上下运动。

车身的上下运动在每一次冲击后会引起跳动和摆动，这样会使得乘客很不舒服。

这种不舒适性可以通过减震器来降低。

Suspension, when discussing cars, refers to the use of the front and rear springs to suspend a vehicle's "sprung" weight. The springs used on today's cars and trucks are constructed in avariety of types, shapes, sizes, rates and capacities. Types include leaf springs, coil springs, air springs, and torsion bars. They may be paired off on vehicles in various combinations and are attached to vehicles by several different mounting techniques.当我们谈论汽车悬架时，是指前后弹簧用来悬挂的汽车重量。

汽车悬架如何工作汽车悬架是汽车重要的组成部分之一，它的主要功能是支撑和连接车身与车轮。

悬架系统在汽车行驶中起到了减震、稳定、保持车身平稳和提高驾乘舒适性的作用。

下面将详细介绍汽车悬架的工作原理。

首先，汽车悬架系统主要由减震器、弹簧、悬臂、悬挂杆、防护杆、撞减杆等组成。

其中，减震器起到了减震和抑制车身较大振动的作用，弹簧则起到了支撑和弹性缓冲作用，而悬臂、悬挂杆、防护杆、撞减杆等则起到了连接车身与车轮的作用。

其次，汽车悬架系统的工作原理可以分为两个方面：一是车轮运动的控制，二是减震功能的实现。

车轮运动的控制主要通过悬挂杆和悬臂来实现。

当汽车行驶时，车轮会受到地面的不平衡力的作用，导致车身产生较大的颠簸。

这时，悬挂杆会起到连接车身和车轮的作用，通过弹簧的支撑和悬臂的运动，使车轮能够相对于车身进行运动，从而减少车身的摆动，并保持良好的行驶稳定性。

悬挂杆的设计和悬臂的长度、弹性系数等都会对车轮运动的控制起到重要的影响。

减震功能的实现主要依靠减震器。

减震器通过其中的油封、活塞和阻尼液压装置等，在车轮受到颠簸时能够消耗一部分能量，减少车身振动，从而提高驾乘的舒适性。

减震器中的阻尼装置具有阻尼力的特性，能够根据车轮的运动变化实时调整阻尼力，使车身始终保持平稳的状态。

同时，减震器还能够对车轮在过减速带、颠簸路面等情况下产生的冲击力起到一定的缓冲作用，保护车身和乘客。

除了以上核心部件，汽车悬架系统还会配备其他辅助装置，如防护杆和撞减杆。

防护杆主要用于防护悬架系统，在遇到碰撞时能够起到保护车身和悬架的作用。

撞减杆则能够在碰撞时通过变形消耗部分碰撞能量，减少对车身和乘客的冲击力。

总体来说，汽车悬架系统通过弹簧支撑和悬臂的运动，使车轮能够相对于车身进行运动，从而减少车身的颠簸。

减震器则通过阻尼装置和阻尼液压装置，消耗部分能量，减少车身振动，提高驾乘舒适性。

悬架系统中配备的防护杆和撞减杆能够在遭受碰撞时起到保护车身和乘客的作用。

附录Ⅰ外文资料及翻译As we review suspension system components and how they work together, remember that a vehicle in motion is more than wheels turning. As the tire revolves, the suspension system is in a dynamic state of balance, continuously compensating and adjusting for changing driving conditions. Today's suspension system is automotive engineering at its best.The components of the suspension system perform six basic functions:1.Maintain correct vehicle ride height2.Reduce the effect of shock forces3.Maintain correct wheel alignment4.Support vehicle weight5.Keep the tires in contact with the road6.Control the vehicle’s direction of travelHowever, in order for this to happen, all the suspension components, both front and rear, must be in good working condition.MAIN COMPONENTS OF A MODERN SUSPENSION SYSTEMAt this point, it's important to understand that the main components of a moving vehicle suspension system are the Struts, Shock Absorbers, Springs and Tires. We will first turn our attention to the design and function of springs. In the following section we will thoroughly examine the function and design of shock absorbers and strut assemblies.The springs support the weight of the vehicle, maintain ride height, and absorb road shock..Springs are the flexible links that allow the frame and the body to ride relatively undisturbed while the tires and suspension follow the bumps in the road.Springs are the compressible link between the frame and the body. When an additional load is placed on the springs or the vehicle meets a bump in the road, the springs will absorb the load by compressing. The springs are a very important component of the suspension system that provides ride comfort. Shocks and strutshelp control how fast the springs and suspension are allowed to move, which is important in keeping tires in firm contact with the road.During the study of springs, the term bounce refers to the vertical (up and down) movement of the suspension system. The upward suspension travel that compresses the spring and shock absorber is called the jounce, or compression. The downward travel of the tire and wheel that extends the spring and shock absorber is called rebound, or extension.When the spring is deflected, it stores energy. Without shocks and struts the spring will extend and release this energy at an uncontrolled rate. The spring's inertia causes it to bounce and overextend itself. Then it re-compresses, but will again travel too far. The spring continues to bounce at its natural frequency until all of the energy originally put into the spring is used.If the struts or shock absorbers are worn and the vehicle meets a bump in the road, the vehicle will bounce at the frequency of the suspension until the energy of the bump is used up. This may allow the tires to lose contact with the road.Struts and shock absorbers that are in good condition will allow the suspension to oscillate through one or two diminishing cycles, limiting or damping excessive movement, and maintaining vertical loads placed upon the tires. This helps keep the tires in contact with the road.By controlling spring and suspension movement, components such as tie rods will operate within their design range and, while the vehicle is in motion, dynamic wheel alignment will be maintained.SPRING DESIGNSBefore discussing spring design, it is important to understand sprung and unsprung weight. Sprung weight is the weight supported by the springs. For example, the vehicle's body, transmission, frame, and motor would be sprung weight. Unsprung weight is the weight that is not carried by springs, such as the tires, wheels, and brake assemblies.The springs allow the frame and vehicle to ride undisturbed while the suspension and tires follow the road surface. Reducing unsprung weight will provide less road shock. A high sprung weight along with a low unsprung weight provides improved ride and also improved tire traction.There are four major spring designs in use today: coil, leaf, torsion bar, and air.Coil SpringsThe most commonly used spring is the coil spring. The coil spring is a length of round spring steel rod that is wound into a coil. Unlike leaf springs, conventional coil springs do not develop inter-leaf friction. Therefore, they provide a smoother ride.The diameter and length of the wire determine the strength of a spring. Increasing the wire diameter will produce a stronger spring, while increasing its length will make it more flexible.Spring rate, sometimes referred to as deflection rate, is used to measure spring strength. It is the amount of weight that is required to compress the spring 1 inch. For example: If it takes 100 lbs. to compress a spring 1inch, it would take to 200 lbs. to compress the spring 2 inches.Some coil springs are made with a variable rate. This variable rate is accomplished by either constructing this spring from materials having different thickness or by winding the spring so the coil will progressively compress at a higher rate. Variable rate springs provide a lower spring rate under unloaded conditions offering a smoother ride, and a higher spring rate under loaded conditions, resulting in more support and control.Coil springs require no adjustment and for the most part are trouble-free. The most common failure is spring sag. Springs that have sagged below vehicle design height will change the alignment geometry. This can create tire wear, handling problems, and wear other suspension components. During suspension service it is very important that vehicle ride height be measured. Ride height measurements not within manufacturer’s specifications require replacement of springs.Leaf SpringsLeaf springs are designed two ways: multi-leaf and mono-leaf. The multi-leaf spring is made of several steel plates of different lengths stacked together. During normal operation, the spring compresses to absorb road shock. The leaf springs bend and slide on each other allowing suspension movement.An example of a mono-leaf spring is the tapered leaf spring. The leaf is thick in the middle and tapers toward the two ends. Many of these leaf springs are made of a composite material, while others are made of steel.In most cases leaf springs are used in pairs mounted longitudinally (front to back). However, there are an increasing number of vehicle manufacturers using a single transverse (side to side) mounted leaf spring.Torsion BarAnother type of spring is the torsion bar. The torsion bar is a straight or L shaped bar of spring steel. Most torsion bars are longitudinal, mounted solidly to the frame at one end and connected to a moving part of the suspension at the other. Torsion bars may also be transverse mounted. During suspension movement, the torsion bar will twist, providing spring action.Air SpringsThe air spring is another type of spring that is becoming more popular on passenger cars, light trucks, and heavy trucks. The air spring is a rubber cylinder filled with compressed air. A piston attached to the lower control arm moves up and down with the lower control arm. This causes the compressed air to provide spring action. If the vehicle load changes, a valve at the top of the airbag opens to add or release air from the air spring. An onboard compressor supplies air.Tires as SpringsAn often-overlooked spring is the tire. Tires are air springs that support the total weight of the vehicle. The air spring action of the tire is very important to the ride quality and safe handling of the vehicle. As a matter of fact, tires may be viewed as the number-one ride control component. Tire size, construction, compound and inflation are very important to the ride quality of the vehicle.STRUT MOUNTDESIGNStrut mounts are vehicle specific, and there are numerous designs in use today on both front and rear suspension systems. The three most common designs are inner plate, center sleeve, and spacer bushing.The Inner Plate Design used by General Motors and some Ford applications feature an inner plate encased in molded rubber surrounded by upper and lower surface plates. The inner plate is designed so the strut piston rod cannot push through the upper or lower surface plate if the rubber core fails. This design generally does not require washers. Due to the fact that the upper and lower service plates mostly cover the rubber portion of the mount, it is difficult to see if the inner rubber bushing has failed. However, these components wear over time and with a thorough inspection a proper recommendation can be made. The bearing is located on the bottom of the strut mount and is not serviceable. Defective bearing will require replacement of the entire strut mount.The Center Sleeve Design used by Chrysler features a center sleeve that is molded to the rubber bushing. This design provides increased side to side stability.The strut stem extends through the center sleeve. Upper and lower retainer washers prevent the strut rod from pushing through the strut mount. The bearing is a separate component from the strut mount. If inspection reveals cracks or tears in the rubber bushing, replacement is required. If the bearing is found to be defective it can be replaced separately.The Spacer Bushing Design used by V olkswagen, Toyota, Mazda, Mitsubishi, and early Chrysler vehicles feature center positioning of the bearing and a separate inner bushing instead of a molded inner sleeve. The operation is similar to the style we just discussed except the bearing is pressed in the strut mount. The bearings, washer, and the upper plate retain the strut rod. If the rubber bushing is cracked, torn, or the bearing is binding or seized, the strut mount requires replacement.ANTI-SWAY BARSAnother important component of a suspension system is the anti-sway bar. This device is used along with shock absorbers to provide additional stability. The anti-sway bar is simply a metal rod connected to both of the lower control arms. When the suspension at one wheel moves up and down the anti-sway bar transfers the movement to the other wheel. In this way the sway bar creates a more level ride and reduces vehicle sway or lean during cornering.Depending of the anti-sway bar thickness and design, it can provide as much as 15% reduction in the amount of vehicle roll or sway during cornering.BUSHINGSBushings are used in many locations on the vehicle suspension system. Most bushings are made with natural rubber. However, in some cases, urethane compounds may be used. Bushings made of natural rubber offer high tensile (tear) strength and excellent stability at low temperatures. Natural rubber is an elastomeric material. Elastomeric refers to the natural elastic nature of rubber to allow movement of the bushing in a twisting plane. Movement is controlled by the design of the rubber element. Natural rubber requires no lubrication, isolates minor vibration, reduces transmitted road shock, operates noise free, and offers a large degree of bushing compliance. Bushing compliance permits movement without binding. Natural rubber resists permanent deflections, is water resistant and very durable. In addition, natural rubber offers high load carrying capabilities.As with all suspension system components, control arm bushings are dynamic components, meaning that they operate while the vehicle is in motion. Control armsact as locators because they hold the position of the suspension in relation to the chassis. They are attached to the vehicle frame with rubber elastomeric bushings. During suspension travel, the control arm bushings provide a pivot point for the control arm. They also maintain the lateral and vertical location of the control arm pivot points, maintain dynamic wheel alignment, reduce transmitted noise, road shock, and vibration, while providing resistance to suspension movement.During suspension travel the rubber portion of the bushing must twist to allow control arm movement. Control arm bushings that are in good condition act as a spring; that is, the rubber will spring back to the position from which it started. This twisting action of the rubber will provide resistance to suspension movement.As previously stated, control arm bushings are dynamic suspension components. As the control arm travels through jounce and rebound, the rubber portion of the bushing will twist and stretch. This action transfers energy into the bushing and generates heat.Excessive heat tends to harden the rubber. As the rubber bushing hardens, it tends to crack, break, and then disintegrate. Its temperature determines the life of a rubber bushing. Rough road conditions and/or defective shock absorbers or struts will allow excessive suspension movement creating more heat, which shortens the life of the bushings.Rubber bushings must not be lubricated with petroleum-based oil. A petroleum-based product will destroy the bushings. Instead, use a special tire rubber lubricant or a silicone based lubricant.Worn suspension bushings allow the control arm to change positions. This results in driveline vibration (primarily rear wheel drive rear control arm bushings), dynamic alignment angle changes, tire wear, and handling problems. Control arm bushing wear (looseness) will create a clunking sound while driving over rough roads.悬架系统的基本元件当我们复习悬架系统组成时，我记得它们是怎么工作的，一辆行驶车的汽车，更应该说是车轮的转动。

附录ISuspension systemsWhen people think of automobile performance, they normally think of horsepower, torque and zero-to-60 acceleration. But all of the power generated by a piston engine is useless if the driver can't control the car. That's why automobile engineers turned their attention to the suspension system almost as soon as they had mastered the four-stroke internal combustion engine.Double-wishbone suspension on Honda Accord 2005 CoupeThe job of a car suspension is to maximize the friction between the tires and the road surface, to provide steering stability with good handling and to ensure the comfort of the passengers. In this article, we'll explore how car suspensions work, how they've evolved over the years and where the design of suspensions is headed in the future.If a road were perfectly flat, with no irregularities, suspensions wouldn't be necessary. But roads are far from flat. Even freshly paved highways have subtle imperfections that can interact with the wheels of a car. It's these imperfections that apply forces to the wheels. According to Newton's laws of motion, all forces have both magnitude and direction. A bump in the road causes the wheel to move up and down perpendicular to the road surface. The magnitude, of course, depends on whether the wheel is striking a giant bump or a tiny speck. Without an intervening structure, all of wheel's vertical energy is transferred to the frame, which moves in the same direction. In such a situation, the wheels can lose contact with the road completely. Then, under the downward force of gravity, the wheels can slam backinto the road surface. What you need is a system that will absorb the energy of the vertically accelerated wheel, allowing the frame and body to ride undisturbed while the wheels follow bumps in the road.A car's suspension, with its various components, provides all of the solutions described.Car Suspension PartsThe suspension of a car is actually part of the chassis, which comprises all of the important systems located beneath the car's body.These systems include:The frame - structural, load-carrying component that supports the car's engine and body, which are in turn supported by the suspension∙The suspension system - setup that supports weight, absorbs and dampens shock and helps maintain tire contact∙The steering system - mechanism that enables the driver to guide and direct the vehicle∙The tires and wheels - components that make vehicle motion possible by way of grip and/or friction with the roadSo the suspension is just one of the major systems in any vehicle.With this big-picture overview in mind, it's time to look at the three fundamental components of any suspension: springs, dampers andanti-sway bars.SpringsToday's springing systems are based on one of four basic designs: Coil springs - This is the most common type of spring and is, in essence, a heavy-duty torsion bar coiled around an axis. Coil springs compress andexpand to absorb the motion of the wheels.Leaf springs - This type of spring consists of several layers of metal (called "leaves") bound together to act as a single unit. Leaf springs were first used on horse-drawn carriages and were found on most American automobiles until 1985. They are still used today on most trucks and heavy-duty vehicles.Coil springs∙ Torsion bars - Torsion bars use the twisting properties of a steelbar to provide coil-spring-like performance. This is how they work: One end of a bar is anchored to the vehicle frame. The other end is attached to a wishbone, which acts like a lever that moves perpendicular to the torsion bar. When the wheel hits a bump, vertical motion is transferred to the wishbone and then, through the levering action, to the torsion bar. The torsion bar then twists along its axis to provide the spring force. European carmakers used this system extensively, through the 1950s and 1960s.Torsion bar∙ Air springs - Air springs, which consist of a cylindrical chamberof air positioned between the wheel and the car's body, use thecompressive qualities of air to absorb wheel vibrations. The concept isactually more than a century old and could be found on horse-drawnbuggies. Air springs from this era were made from air-filled, leather diaphragms, much like a bellows; they were replaced with molded-rubber air springs in the 1930s.Photo courtesy HowStuffWorksShopper Leaf springAir springsBased on where springs are located on a car -- i.e., between the wheels and the frame -- engineers often find it convenient to talk about the sprung mass and the unsprung mass.Springs: Sprung and Unsprung MassThe sprung mass is the mass of the vehicle supported on the springs, while the unsprung mass is loosely defined as the mass between the road and the suspension springs. The stiffness of the springs affects how the sprung mass responds while the car is being driven. Loosely sprung cars, such as luxury cars (think Lincoln Town Car), can swallow bumps and provide a super-smooth ride; however, such a car is prone to dive and squat during braking and acceleration and tends to experience body sway or roll during cornering. Tightly sprung cars, such as sports cars (think Mazda Miata), are less forgiving on bumpy roads, but they minimize body motion well, which means they can be driven aggressively, even around corners.So, while springs by themselves seem like simple devices, designing and implementing them on a car to balance passenger comfort with handling is a complex task. And to make matters more complex, springs alone can't provide a perfectly smooth ride. Why? Because springs are great at absorbing energy, but not so good at dissipating it. Other structures, known as dampers, are required to do this.Dampers: Shock AbsorbersUnless a dampening structure is present, a car spring will extend and release the energy it absorbs from a bump at an uncontrolled rate. The spring will continue to bounce at its natural frequency until all of the energy originally put into it is used up.A suspension built on springs alone would make for an extremely bouncy ride and, depending on the terrain, an uncontrollable car.Enter the shock absorber, or snubber, a device that controls unwanted spring motion through a process known as dampening. Shock absorbers slow down and reduce the magnitude of vibratory motions by turning the kinetic energy of suspension movement into heat energy that can be dissipated through hydraulic fluid. To understand how this works, it's best to look inside a shock absorber to see its structure and function.A shock absorber is basically an oil pump placed between the frame of the car and the wheels. The upper mount of the shock connects to the frame (i.e., the sprung weight), while the lower mount connects to the axle, near the wheel (i.e., the unsprung weight). In a twin-tube design, one of the most common types of shock absorbers, the upper mount is connected to a piston rod, which in turn is connected to a piston, which in turn sits in a tube filled with hydraulic fluid. The inner tube is known as the pressure tube, and the outer tube is known as the reserve tube. The reserve tube stores excess hydraulic fluid.When the car wheel encounters a bump in the road and causes the spring to coil and uncoil, the energy of the spring is transferred to the shock absorber through the upper mount, down through the piston rod and into the piston. Orifices perforate the piston and allow fluid to leak through as the piston moves up and down in the pressure tube. Because the orifices are relatively tiny, only a small amount of fluid,under great pressure, passes through. This slows down the piston, which in turn slows down the spring.Shock absorbers work in two cycles -- the compression cycle and the extension cycle. The compression cycle occurs as the piston moves downward, compressing the hydraulic fluid in the chamber below the piston. The extension cycle occurs as the piston moves toward the top of the pressure tube, compressing the fluid in the chamber above the piston. A typical car or light truck will have more resistance during its extension cycle than its compression cycle. With that in mind, the compression cycle controls the motion of the vehicle's unsprung weight, while extension controls the heavier, sprung weight.All modern shock absorbers are velocity-sensitive -- the faster the suspension moves, the more resistance the shock absorber provides. This enables shocks to adjust to road conditions and to control all of the unwanted motions that can occur in a moving vehicle, including bounce, sway, brake dive and acceleration squat.Anti-sway barsAnti-sway BarsAnti-sway bars are used along with shock absorbers to give a moving automobile additional stability. An anti-sway bar is a metal rod that spans the entire axle and effectively joins each side of the suspension together.When the suspension at one wheel moves up and down, the anti-sway bar transfers movement to the other wheel. This creates a more level ride and reduces vehicle sway. In particular, it combats the roll of a car on its suspension as it corners. For this reason, almost all cars today are fitted with anti-sway bars as standard equipment, although if they're not, kits make it easy to install the bars at any time.译文悬架系统当人们想到汽车性能，通常先到的是是马力，转矩和0到60公里的加速度。

外文翻译--汽车悬架工作原理附录3英文原文How Car Suspensions WorkBy William HarrisUniversity of MichiganWhen people think of automobile performance, they normally think of horsepower, torque and zero-to-60 acceleration. But all of the power generated by a piston engine is useless if the driver can't control the car. That's why automobile engineers turned their attention to the suspension system almost as soon as they had mastered the four-stroke internal combustion engine.Photo courtesy Honda Motor Co., Ltd.Double-wishbone suspension on Honda Accord 2005 CoupeThe job of a car suspension is to maximize the friction between the tires and the road surface, to provide steering stability with good handling and to ensure the comfort of the passengers. In this article, we'll explore how car suspensions work, how they've evolved over the years and where the design of suspensions is headed in the future.Vehicle DynamicsIf a road were perfectly flat, with no irregularities, suspensions wouldn't be necessary. But roads are far from flat. Even freshly paved highways have subtle imperfections that can interact with the wheels of a car. It's these imperfections that apply forces to the wheels. According to Newton's laws of motion, all forces have both magnitude and direction. A bump in the road causes the wheel to move up and down perpendicular to the road surface. The magnitude, of course, depends on whether the wheel is striking a giant bump or a tiny speck. Either way, the car wheel experiences a vertical acceleration as it passes over an imperfection.Without an intervening structure, all of wheel's vertical energy is transferred to the frame, which moves in the same direction. In such a situation, the wheels can lose contact with the road completely. Then, under the downward force of gravity, the wheels can slam back into the road surface. What you need is a system that will absorb the energy of the vertically accelerated wheel, allowing the frame and body to ride undisturbed while the wheels follow bumps in the road.The study of the forces at work on a moving car is called vehicle dynamics, and you need to understand some of these concepts in order to appreciatewhy a suspension is necessary in the first place. Most automobile engineers consider the dynamics of a moving car from two perspectives:Ride - a car's ability to smooth out a bumpy roadHandling - a car's ability to safely accelerate, brake and cornerThese two characteristics can be further described in three important principles - road isolation, road holding and cornering. The table below describes these principles and how engineers attempt to solve the challenges unique to each.A car's suspension, with its various components, provides all of the solutions described.Let's look at the parts of a typical suspension.The ChassisThe suspension of a car is actually part of the chassis, which comprises all of the important systems located beneath the car's body.These systems include:The frame - structural, load-carrying component that supports the car's engine and body, which are in turn supported by the suspensionThe suspension system - setup that supports weight, absorbs and dampens shock and helps maintain tire contactThe steering system - mechanism that enables the driver to guide and direct the vehicleThe tires and wheels - components that make vehicle motion possible by way of grip and/or friction with the roadSo the suspension is just one of the major systems in any vehicle.With this big-picture overview in mind, it's time to look at the three fundamental components of any suspension: springs, dampers and anti-sway bars. SpringsToday's springing systems are based on one of four basic designs: Coil springs This is the most common type of spring and is, in essence, aheavy-duty torsion bar coiled around an axis. Coil springs compress and expand to absorb the motion of the wheels.Leaf springs - This type of spring consists of several layers of metal (called "leaves") bound together to act as a single unit. Leaf springs were first used on horse-drawn carriages and were found on most American automobiles until 1985. They are still used today on most trucks and heavy-duty vehicles.Torsion bars - Torsion bars use the twisting properties of a steel bar to provide coil-spring-like performance. This is how they work: One end of a bar is anchored to the vehicle frame. The other end is attached to a wishbone, which acts like a lever that moves perpendicular to the torsion bar. When the wheel hits a bump, vertical motion is transferred to the wishbone and then, through the levering action, to the torsion bar. The torsion bar then twists along its axis to provide the spring force. European carmakers used this system extensively, as did Packard and Chrysler in the United States, through the 1950s and 1960s.Air springs - Air springs, which consist of a cylindrical chamber of air positioned between the wheel and the car's body, use the compressive qualities of air to absorb wheel vibrations. The concept is actually more than a century old and could be found on horse-drawn buggies. Air springs from this era were made from air-filled, leather diaphragms, much like a bellows; they were replaced with molded-rubber air springs in the 1930s. Based on where springs are located on a car -- i.e., between the wheels and the frame -- engineers often find it convenient to talk about the sprung mass and the unsprung mass.Springs: Sprung and Unsprung MassThe sprung mass is the mass of the vehicle supported on the springs, while the unsprung mass is loosely defined as the mass between the road and the suspension springs. The stiffness of the springs affects how the sprung mass responds while the car is being driven. Loosely sprung cars, such asluxury cars (think Lincoln Town Car), can swallow bumps and provide a super-smooth ride; however, such a car is prone to dive and squat during braking and acceleration and tends to experience body sway or roll during cornering. Tightly sprung cars, such as sports cars (think Mazda Miata), are less forgiving on bumpy roads, but they minimize body motion well, which means they can be driven aggressively, even around corners.So, while springs by themselves seem like simple devices, designing and implementing them on a car to balance passenger comfort with handling is a complex task. And to make matters more complex, springs alone can't provide a perfectly smooth ride. Why? Because springs are great at absorbing energy, but not so good at dissipating it. Other structures, known as dampers, are required to do this.Dampers: Shock AbsorbersUnless a dampening structure is present, a car spring will extend and release the energy it absorbs from a bump at an uncontrolled rate. The spring will continue to bounce at its natural frequency until all of the energy originally put into it is used up. A suspension built on springs alone would make for an extremely bouncy ride and, depending on the terrain, an uncontrollable car.Enter the shock absorber, or snubber, a device that controls unwanted spring motion through a process known as dampening. Shock absorbers slow down and reduce the magnitude of vibratory motions by turning the kinetic energy of suspension movement into heat energy that can be dissipated through hydraulic fluid. To understand how this works, it's best to look inside a shock absorber to see its structure and function.附录4英文翻译汽车悬架工作原理William Harris密歇根大学当人们想到汽车性能时，他们通常想起的是马力，扭矩，0到60加速时间。

The development of automobile suspensionAutomobile suspension system is a connecting structure system between the body and frame and wheels, and the structural system includes shock absorbers, suspension springs, anti roll bars, suspension side beam, lower control arm, longitudinal bar, steering knuckle arm, rubber bushing and connecting rod etc.. When the car on the road because of the ground change by the vibration and impact, the impact strength of one part by tire absorption, but mostly rely on suspension tire and the body to absorb. In the running process of the automobile suspension, the role is to connect the axle and the frame flexibility, slow moving vehicle impact force caused by uneven pavement, ensure the ride comfort and the goods, due to the rapid decay caused by the vibration of elastic system, vertical, longitudinal and lateral transfer to force and torque, and play a leading role. The wheel according to a certain trajectory relative to body movement. Suspension is one of the most important parts of modern automobile. The typical suspension structure is made up of elastic element, guide mechanism and shock absorber, etc., and there are buffer blocks, transverse stabilizer bars and so on. The elastic element is composed of a steel plate spring, an air spring, a spiral spring and a torsion bar spring, etc. the modern car suspension adopts a spiral spring and a torsion bar spring.Types and working principle of suspensionAccording to the suspension damping and stiffness changes with the change of driving conditions, can be divided into passive suspension, semi-active suspension and active suspension, semi-active suspension can also be divided into two types of damping and variable type. The traditional system of suspension stiffness and damping coefficient is selected according to the experience design and optimization design method, once selected, in the course of the vehicle, it can not be adjusted, so the damping performance limits further enhance, the suspension has become passive suspension. In order to overcome the defects of passive suspension, the concept of active suspension was proposed in 1960s, which is composed of active or passive components. It is a closed loop control system, according to the movement of the vehicle and the state of the road to take the initiative to respond to restrain the movement of the body, so that the suspension is always in the best state of shock.Therefore, the characteristics of active suspension is to adapt to the changes of the external input or the vehicle itself. So the system must be active. Semi active suspension is composed of passive but controllable damping elements. In the vehicle suspension, in addition to absorbing and storing energy, the elastic element also has to bear the weight and the load of the vehicle body. Therefore, the semi-active suspension does not consider changing the stiffness of the suspension. Because of the semi active suspension structure is simple, in the work, almost does not consume the vehicle power, but also can get similar performance with the active suspension, it is widely used. Due to random road input, control of vehicle suspension damping belongs to adaptive control system is designed, changes occur in a wide range of input or interference, adaptive environment, adjusting the system parameters, so that the output can be controlled effectively, meet the design requirements. It is different from the general feedback control system because it deals with the feedback information with "uncertainty". The adaptive control system according to the principle of different, can be divided into tuning regulator and model reference adaptive control system of two categories, because it is difficult to establish a precise "vehicle bottom" system model, the active suspension, the use of self correction regulator. Although there are many kinds of modern automobile, the structure difference is big, but it is generally composed of elastic element, damping element and guiding component. The working principle is that when the automobile tire is impacted, the elastic element is used for buffering the impact to prevent damage to the automobile components and personnel. However, the elastic parts will be affected by the growth time of sustained vibration, easy to make the driver fatigue. Therefore, the vibration damping elements should be quickly damped vibration. When the wheel is hit by the impact, it should be consistent with the trajectory of certain requirements, otherwise it will reduce the ride comfort and handling stability of the vehicle. The direction of the steering component must be controlled at the same time.The history and present situation of suspensionIn the carriage appeared, in order to ride more comfortable, humans began to ride the suspension of a leaf spring tireless exploration. In 1776, the leaf spring of the carriage was patented, and it was used until 1930s. After the birth of the car, with the in-depth study of thesuspension, the torsion spring, gas spring, rubber spring, leaf spring, etc.. In 1934, the world's first passive suspension composed of helical springs. The parameters of the passive suspension are determined according to the experience or the method of optimal design. It is a series of road compromise, it is difficult to adapt to a variety of complex road conditions, the effect of poor damping. In order to overcome this defect, the nonlinear stiffness spring and the adjustment of the height of the body are adopted. Although the results are satisfactory, the disadvantages of passive suspension can not be eliminated. The passive suspension is mainly used in low-grade cars, the front suspension of modern cars generally use the Mcpherson suspension with stabilizer bar, choose more after the suspension, the main composite longitudinal swing arm suspension and multi link suspension. Semi active suspension research began in 1973, first proposed by D.A.Crosby and D.C.Karnopp. Semi active suspension is mainly used to change the damping of suspension. The working principle is as follows: according to the control law of the spring, the damping force or stiffness of the spring can be adjusted according to the feedback signal of the spring mass relative to the wheel speed response and acceleration response. The semi-active suspension is similar to the passive suspension, but its damping or stiffness coefficient can be adjusted according to the running state, which is similar to that of the active suspension. A type of semi active suspension damping is divided into several stages, the damping level by the driver according to the "road" or by the sensor signal automatic selection; stepless semi-active suspension based on road conditions and vehicle driving state of suspension within a few milliseconds from the minimum to the stepless speed regulation. Due to the relatively simple structure of the semi-active suspension, the work does not need to consume the power of the vehicle, and can obtain the same performance with the active suspension, has a broad space for development. With the continuous development of road traffic, vehicle speed has been greatly improved, the passive suspension has gradually become the bottleneck of improving the performance of vehicle, so people can develop both comfort and handling stability of active suspension. The concept of active suspension is the first proposed in the suspension design of General Motors Corporation in 1954. On the basis of the passive suspension, it can increase the stiffness and damping of the control device, so that the suspension of the car on any road to maintain thebest running state. The control device is composed of measuring system, feedback control system and energy system. In 1980s, the world's leading automobile companies and manufacturers competing to develop and develop this suspension. Mercedes Benz, V olvo, Lotts, TOYOTA, etc. in the car on a more successful test. Equipped with active suspension of the car, in the bad road high speed, the body is very stable, the tire noise is small, steering and braking body to maintain the level of. The utility model is characterized in that the ride is very comfortable, but the structure is complex, the energy consumption is high, the cost is high, and the reliability is different.Due to various reasons, most of China's automotive passive suspension. In the study of semi-active and active suspension started late, with a large gap between foreign countries. In the western developed countries, semi active suspension in the late 1980s tends to mature, Ford Motor Co and Nissan first in the car application, and achieved good results. Although the active suspension has been put forward earlier, it is difficult to make a big breakthrough because of its complicated control and many subjects. Into 1990s, throwing only applies to the large amount of luxury cars. There is no report of domestic automotive products using this technology, only a few research institutions such as Beijing Institute of Technology and Tongji University to study the active suspension.Development trend of suspensionDue to the requirements of ride comfort and handling stability, a safe, intelligent and clean green intelligent suspension will be the future development trend of automobile suspension. Passive suspension is a traditional mechanical mechanism, stiffness and damping are not adjustable, according to the theory of random vibration, it can only ensure that the specific road conditions to achieve better results. However, its theory is mature, simple structure, reliable performance, relatively low cost and does not require additional energy, which is the most widely used. In our country, there is still a high research value. Study on passive suspension performance mainly in three aspects: through analyzing the stress of the car after the establishment of mathematical model, the optimal parameters and then use the computer simulation technology or finite element method for suspension; damper of variable stiffness spring and variable damping suspension, make good operation in most of the roadstudy; guiding mechanism, make the car suspension to meet the comfortUnder the premise, the stability has improved greatly. The research of semi-active suspension is focused on two aspects: the research of execution strategy and the research of actuator. There are two kinds of damping adjustable shock absorber, one is to adjust the damping by changing the size of the orifice. The size of the throttle hole in general through the solenoid valve or stepper motor for a level or stepless adjustment, this method is more expensive, complex structure. The damping coefficient can be changed by changing the viscosity of the damping fluid, which has the characteristics of simple structure, low cost, no noise and shock. The research of active suspension is also focused on two aspects: reliability; actuator. The active suspension with a large number of sensors, MCU, input and output circuit and the interface, because of more components, reduces the reliability of the suspension, therefore, increase the degree of integration of elements, is an impassable stage. The actuator is mainly used to replace the hydraulic components of electric devices. The linear servo motor and permanent magnet DC linear servo motor in electric power system have many advantages, which will replace the hydraulic actuator in the future. Based on the principle of electromagnetic energy storage and the self tuning controller of parameter estimation, a high performance and low power electromagnetic active adaptive suspension can be designed. With the development of the traffic, the highway is improving gradually, and the speed of the car is faster and faster. The automobile suspension system to support force, the road acting on the wheel longitudinal force and lateral force and the reaction force caused by the torque is transmitted to the frame, in order to ensure the normal running of the vehicle, therefore has a crucial influence on the vehicle driving vehicle suspension system, dynamic simulation of the automobile suspension system is very high status in vehicle design and development. In the field of automobile engineering, simulation software can avoid duplication of manufacturing parts and prototype in product development process, resources, reduce the waste of time and money, a study on the power can be better kinematics in automotive engineering field using simulation software. Foreign countries have developed IMP, ADAMS and DAMN simulation software for the field of automotive kinematics.ConclusionWith Solidworks, Pro/E, CATIA, UG, ADAMS, ANSYS and other CAD/CAE software development, plays a key role in the research and development of automobile suspension, through finite element method, computer simulation technology, reduce the enterprise cost of research and development of computer optimization design method, shorten the development cycle. Generally speaking, the active suspension has good damping effect and superior performance, and solves the contradiction of ride comfort and handling stability. But the component cost is higher, work needs more energy, vehicle quality also increased, so the active suspension will greatly increase the cost and energy consumption; the damping performance of the semi-active suspension close to active suspension, steering stability is better than passive suspension. It is the only way for the development of semi-active suspension that the performance is reliable, the adjustable damping damper and the simple and effective control strategy. The performance of passive suspension is the worst, but it has the lowest cost and no need to consume energy. Passive suspension in a certain period of time will be the most widely used suspension system, by further optimizing the suspension structure and parameters can continue to improve the suspension performance.汽车悬架的发展历程汽车的悬架系统是指车身、车架和车轮之间的一个连接结构系统，而这个结构系统包含了避震器、悬架弹簧、防倾杆、悬吊副梁、下控臂、纵向杆、转向节臂、橡皮衬套和连杆等部件。

附录AThe automotive vehicle suspension system frame (or Unibody) and axle (or wheel) power transmission connection between all devices in general. Its function is to act on the road wheels on the vertical force (support force), the vertical reaction force (traction and braking) and lateral reaction force and the torque reaction force caused by the transfer to the frame (or Unibody) on, in order to ensure the normal running car. Therefore, the suspension system performance and quality performance for the vehicle plays an important role. This paper suspension systems for passenger cars and trucks in the widely used leaf spring design calculation method for the in-depth analysis and research.The article on the current variety of automotive leaf spring design calculation method of intensive analysis and research, summed up the characteristics of various calculation methods, limitations and application. Automotive leaf spring from the elastic component in addition to the role, but also and play the guiding role, and multi-chip friction between the spring damping system also played. As the leaf spring structure is simple, use and maintenance, and easy maintenance, long leaf springs are widely used in the car. Usually the new car design, according to the layout of a given space vehicle, axle load full load minus the estimated quality of non-sprung mass, obtained in each pair of spring bearing on the quality. Generally before the rear axle, wheels, brake drums and steering knuckle, transmission shaft, steering assembly, such as non-vertical rod sprung mass. If the layout of the axle above the leaf spring, spring 3 / 4 the quality of the non-sprung mass, the next set spring, 1 / 4 non-sprung mass spring mass models based on different requirements, general arrangement is given by the straight length of spring control size.In the arrangement possible, try to increase the length of the spring, mainly to consider the following reasons. As the spring stiffness and is inversely proportional to the cube of the length of the spring, so from the perspective of improving vehicle ride comfort, hope springs length longer good. In the spring stiffness of the same case, the long wheel up and down in the spring, the spring from the two ears changes the volume is relatively small, the front suspension, the caster angle change is small, in favor of auto driving stability. Increase the length of the spring can reduce stress andstress amplitude spring working to improve spring life. Can be used to increase the length of the spring reed thick spring, thereby reducing the number of springs and spring reed thick volume ear piece to improve the strength of the main vehicle sprung mass vibration system with quality components to evaluate the natural frequency of vehicle ride comfort important parameters. Suspension design based on vehicle ride comfort requirements, should be given an empty car, fully loaded, front and rear suspension frequency range. If you know the frequency, you can find the suspension static deflection. Select the suspension static deflection, the hope after the suspension static deflection is less than the front suspension static deflection, and the best value close to two vehicles in order to prevent uneven roads often hit the buffer block, suspension design must be given adequate deflection value. Suspension dynamic deflection and car usage and the value of the static deflection due to ride height, suspension travel and dynamic properties of steel spring guide are all fully loaded car with a high arc, and therefore the arc spring loaded high-value should be based on vehicle and suspension performance requirements are given the appropriate value. Some vehicles get good handling and stability, full arc high negative value.附录B汽车悬架系统是汽车车架(或承载式车身)与车桥(或车轮)之间的一切传力连接装置的总称。

附录A 译文汽车悬架如何工作By William HarrisUniversity of Michigan当人们考虑汽车性能的时候，他们通常认为是马力，扭矩和零到60的加速时间。

但是，如果司机无法控制汽车，由一个活塞发动机产生的功率都是无用的。

这就是为什么汽车的工程师开始将注意力转向悬挂系统，尽快为他们几乎已经掌握了四冲程内燃机。

双横臂独立悬架的本田雅阁轿跑车2005年汽车悬架的工作是尽量在轮胎和路面之间提供良好的操纵稳定性，并确保乘客的舒适度。

在这篇文章中，我们将探讨汽车悬架如何的工作，他们已经逐渐发展起来，这些年来，那里的悬架设计在未来的发展方向。

1.车辆动力学如果道路是完全平坦，没有违规行为，就没有必要停牌。

但远离道路平坦，即使是刚铺好的公路有细微的缺陷，与汽车的车轮相联系的。

它的这些缺陷聚焦于车轮。

根据牛顿运动定律，所有部队都大小和方向。

一个在路上碰到导致车轮向上和向下移动到垂直路面。

当然大小，取决于是否是惊人的一个巨大的车轮碰撞或一点点。

无论哪种方式，车轮垂直加速度的经验，因为它传递了一个缺陷。

如果没有中间结构，所有车轮的垂直能量转移到车架，这在同一方向移动。

在这种情况下，车轮与路面可以完全失去联系。

接着，在向下的重力，车轮可以大满贯回路面。

你需要的是一个系统，将吸收的能量垂直加速轮，使画面和身体不受干扰，而车轮按照道路颠簸。

对在工作力量上开动的汽车上被称为车辆动力学研究，你需要了解其中一些概念，以明白为什么暂停把必要摆在首位。

大多数汽车工程师从两个角度考虑的一个移动的汽车的动态：1）乘坐—汽车的能力，理顺了不平坦的道路2）处理—汽车的能力，安全地加速，刹车和角落这两个特点可以进一步说明在三个重要的原则—道路隔离，道路控股和转弯。

下表描述了这些原则和工程师如何尝试解决每一个独特的挑战。

汽车的悬挂其各个组成部分，提供了解决方案，所有描述。

2.底盘系统一辆汽车的悬挂，其实就是在底盘，其中包括对汽车底下找到了所有重要系统的一部分。