Automobile Brake System
The braking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the kinetic energy (momentum) of the vehicle into thermal energy ( stepping on the brakes, the driver commands a stopping force ten times as powerful as the force that puts the car in motion. The braking system can exert thousands of pounds of pressure on each of the four brakes.
Two complete independent braking systems are used on the car. They are the service brake and the parking brake.
The service brake acts to slow, stop, or a separate parking brake foot pedal or extreme conditions, fills the system. “Shoes” and “pads” are pushed by the slave cylinders to contact the “drums” and “rotors” thus causing drag, which ( front and either disk or drum brakes in the rear connected by a system of tubes and brakes. When the driver applies the brake, the control device forces brake shoes, or pads, against the rotating brake drum or disks at wheel. Friction between the shoes or pads and the drums or disks then slows or stops the wheel so that the car is braked.
In most modern brake systems (see Figure 15.1), there is a fluid-filled cylinder, called master cylinder, which contains two separate sections, there is a piston in each section and both pistons are connected to a brake
pedal in the driver’s compartment. When the brake is pushed down, brake fluid is sent from the master cylinder to the wheels.
At the wheels, the fluid pushes shoes, or pads, against revolving drums or disks. The friction between the stationary shoes, or pads, and the revolving drums or disks slows and stops them. This slows or stops the revolving wheels, which, in turn, slow or stop the car.
The brake fluid reservoir is on top of the master cylinder. Most cars today see the level without opening the cover. The brake fluid level will drop slightly as the brake pads wear. This is a normal condition and no cause
for concern. If the level drops noticeably over ashort period of time or goes down to about two thirds full, as possible. Keep the reservoir covered except for the amount of time you need to fill it and never leave a cam of brake fluid uncovered. Brake fluid must maintain a very places that require flexibility, such as at the front wheels, which move up and down as well as steer. The rest of the system uses non-corrosive seamless steel tubing with special fittings at all attachment points. If a steel line requires a repair, the best procedure is to replace the compete line. If this is not practical, a line can be repaired using special splice fittings that are made for brake system repair. You must never use copper tubing to repair a brake system. They are dangerous and illegal.
Drum brakes, it consists of the brake drum, an expander, pull back springs, a stationary back plate, two shoes with friction linings, and anchor pins. The stationary back plate is secured to the flange of the axle the wheel
the inner surface of the drum and the shoe lining. To apply brakes, the driver pushes pedal, the expander expands the shoes and presses them to the drum. Friction between the brake drum and the friction linings brakes the wheels and the vehicle stops. To release brakes, the driver release the pedal, the pull back spring retracts the shoes thus permitting free rotation of the wheels.
Disk brakes, it each side of the disk. The shoes squeeze the rotatin g disk to stop the car. Fluid from the master cylinder forces the pistons to move in, toward the disk. This action pushes the friction pads tightly against the disk. The friction between the shoes and disk slows and stops it. This provides the braking action. Pistons are made of either plastic or metal. There are three general types of disk brakes. They are the floating-caliper type, the fixed-caliper type, and the sliding-caliper type. Floating-caliper and sliding-caliper disk brakes use a single piston. Fixed-caliper disk brakes the parking brakes fitted in all automobile. When the brake pedal is depressed, the rod pushes the piston of brake master cylinder which presses the fluid. The fluid flows through the pipelines to the power brake unit and then to the wheel cylinder. The fluid pressure expands the cylinder pistons thus pressing the shoes to the drum or disk. If the pedal is released, the piston returns to the initialposition, the pull back springs retract the shoes, the fluid is forced back to the master cylinder and braking ceases.
The primary purpose of the parking brake is to a separate parking
braki ng the car the “on” position. The car may now be left without fear
of its rolling away. When the driver wants to move the car again, before the lever can be released. The the event of the foot brake failing. For this reason, it is separate from the foot brake uses cable or rods instead of the slippery pavement or during a panic stop.
Anti-lock brake systems used on aircraft for years, and some domestic car were offered with an early form of anti-lock braking in late 1990’s. Recently, several automakers Europe, where anti-lock brakin g systems available for a decade, and a force several times per second to basically the same way. One or more speed sensors generate alternating current signal whose frequency increases with the wheel rotational speed. An electronic control unit continuously monitors these signals and if the frequency of a signal drops too rapidly indicating that a wheel is about to lock, the control unit instructs a modulating device to reduce sensor signals indicate the wheel is again rotating normally, the control unit allows increased addition to their basic operation, anti-lock systems common. First, they do not operate until the brakes are applied with enough force to lock or nearly lock a wheel. At all other times, the system stands ready to function but does not interfere with normal braking. Second, if the anti-lock system fail in any way, the brakes continue to operate without anti-lock capability. A warning light on the instrument panel alerts the driver when a problem exists in the anti-lock system.
The current Bosch component Anti-lock Braking System (ABSⅡ), is a second generation design wildly used by European automakers such as
BWM, Mercedes-Benz and Porsche. ABSⅡsystem consists of : four wheel speed sensor, electronic control unit and modulator assembly.
A speed sensor is fitted at each wheel sends signals about wheel rotation to control unit. Each speed sensor consists of a sensor unit and a gear wheel. The front sensor mounts to the steering knuckle and its gear wheel is pressed onto the stub axle that rotates with the wheel. The rear sensor mounts the rear suspension member and its gear wheel is pressed onto the axle. The sensor itself is a winding with a magnetic core. The core creates a magnetic field around the winding, and as the teeth of the gear wheel move through this field, an alternating current is induced in the winding. The control unit monitors the rate o change in this frequency to determine impending brake lockup.
The control unit’s function can be divid ed into three parts: signal processing, logic and safety circuitry. The signal processing section is the converter that receives the alternating current signals form the speed sensors and converts them into digital form for the logic section. The logic section then analyzes the digitized signals to calculate any brake pressure changes needed. If impending lockup is sensed, the logic section sends commands to the modulator assembly.
Modulator assembly
The it receives commands from the control utuit. The modulator assembly can maintain or reduce pressure over the level it receives from the master cylinder, it also can never apply the brakes by itself. The
modulator assembly consists of three delivery pump equipped with inlet and outlet check valves. The modulator electrical connector and controlling relays are concealed under a plastic cover of the assembly.
Each front wheel is served by electric solenoid valve modulated independently by the control unit. The rear brakes are served by a single solenoid valve and modulated together using the select-low principle. During anti-braking system operation, the control unit cycles the solenoid valves to either pressure is released from the brake lines during
anti-braking operation, it is routed to a fluid reservoir. There is one reservoir for the front brake circuit. The reservoirs are low-pressure accumulators that store fluid under slight spring pressure until the return delivery pump can return the fluid through the brake lines to the master cylinder.
汽车制动系统
制动系统是汽车中最重要的系统。如果制动失灵，结果可能是损失惨重的。制动器实际就是能量转换装置，它将汽车的动能（动量）转化成热能（热量）。当驾驶员踩下制动踏板，所产生的制动力是汽车运动时动力的10倍。制动系统能对四个刹车系统中的每个施加数千磅的力。
每辆汽车上使用两个完全独立的制动系统，即行车制动器和驻车制动器。
行车制动器起到减速、停车、或保持车辆正常行驶。制动器是由司机用脚踩、松制动器踏板来控制的。驻车制动器的主要作用就是当车内无人的时
候，汽车能够保持静止。当独立的驻车制动器—踏板或手杆，被安装时，驻车制动器就会被机械地操作。
制动系统是由下列基本的成分组成:位于发动机罩下方，而且直接地被连接到制动踏板的“制动主缸”把驾驶员脚的机械力转变为液压力。钢制的“制动管路”和有柔性的“制动软管”把制动主缸连接到每个轮子的“制动轮缸”上。制动液, 特别地设计为的是工作在极端的情况，填充在系统中。“制动盘”和“衬块”是被制动轮缸推动接触“圆盘”和“回转体”如此引起缓慢的拖拉运动, (希望)使汽车减慢速度。
典型的制动系统布置有前后盘式，前盘后鼓式，各个车轮上的制动器通过一套管路系统连接到制动主缸上。
基本上讲，所有的汽车制动器都是摩擦制动器。当司机刹车时，控制装置会迫使制动蹄，或制动衬片与车轮处的旋转的制动鼓或制动盘接触。接触后产生的摩擦使车轮转动减慢或停止，这就是汽车的制动。
在最基本的制动系统中，有一个制动主缸，这个主缸内部填充制动液，并包含两个部分，每个部分里都有一个活塞，两个活塞都连接驾驶室里的制动踏板。当制动踏板被踩下时，制动液会从制动主缸流入轮缸。在轮缸中，制动液推动制动蹄或制动衬片与旋转的制动鼓或制动盘接触。静止的制动蹄或制动衬片与旋转的制动鼓或制动盘之间产生摩擦力使汽车的运动逐渐减缓或停止。
制动液的装置位于主缸的顶部。目前大多数的车都有一个容易看见的装制动液的装置，为的是不用打开盖子就可以看得见制动液的油面。随着制动踏板的运动制动液就会缓慢的下降，正常情况下是这样的。如果制动液在
很短的时间内下降得明显或者下降了三分之二，那么就要尽快的检查你的制动系统了。保持制动液装置充满制动液除非你需要维修它，制动液必须保持很高的沸点。位于在空气中的制动液就会吸收空气中的潮气引起制动液低于沸点。
制动液通过一系列的管路从主缸到达各车轮。橡胶软管只用在需要弹力的地方，比如应用在前轮。在车的行进中上下来回运动。系统的其它部分在所有的连接点上都应用了无腐蚀性的无缝钢管。如果钢线需要修理的话，最好的方法就是代替这条线。如果这不符合实际，那么为了制动系统可以用特殊的装置修理它。你不可以用铜管来修理制动系。它们是危险也是不正确的。
鼓式制动器包括制动鼓，一个轮缸，回拉弹簧，一个制动底版，两个带摩擦层的制动蹄。制动底版固定在轮轴外部的法兰或转向节。制动鼓固定在轮毂上。制动鼓的内部表面与制动蹄的内层之间有空隙。要使用制动器时，司机就要踩下踏板，这时轮缸扩大制动片，对其施加压力，是制动蹄触碰制动鼓。制动鼓与摩擦片之间产生的摩擦制动了车轮，从而使汽车停止。要释放制动器时，司机松开踏板，回拉弹簧拉回制动片，这样车轮会自由转动。
盘式制动器包括制动盘而不是鼓，在它的两面上各有一个薄的制动片或叫盘式制动器的制动片。制动片是靠挤住旋转的制动盘来停住汽车。制动主缸里流出的制动液迫使活塞向里部的金属盘移动，这便使摩擦片紧紧地贴住制动盘。这时制动片与制动盘产生的摩擦使汽车减速、停止，出现了制动行为。活塞分金属或塑料。盘式制动器主要有三种，即：浮动卡钳型、
固定卡钳型和滑动卡钳型。浮动卡钳型和滑动卡钳型盘式制动器使用单活塞。固定卡钳型盘式制动器既可以使用两个活塞有可以使用四个活塞。
制动系统是由机械能，液压能或气压能装置驱动的。在机械杠杆适合所有的汽车的驻车制动器中使用。当踩下制动踏板时，杠杆就会推动制动器主缸的活塞给制动液施加压力，制动液通过油管流入轮缸。制动液的压力施加到轮缸活塞以使制动片被压到制动鼓或制动盘上。如果松开踏板，活塞回到原来的位置上，回拉弹簧拉回制动片，制动液返回制动主缸，这样制动停止。
驻动制动器的主要作用是车内无人时，使汽车静止不动。如果车内安装的是独立的驻车制动器，那么驻车制动器是由司机手动的控制。驻车制动器正常是当车已经停止时使用的。向后拉手闸，并把手柄卡在正确的位置上。现在，即使离开汽车也不用害怕它会自己滑走。如果司机要再次启车时，他必须在松开手杆之前按下按钮。在行车制动器失灵的情况下，手闸必须能停住车。正因为这样，手闸与脚闸分开，手闸使用的是绳索或杠杆而不是液力系统。
防抱死制动系统是使汽车制动更安全、更方便的制动装置，它既有调节制动系统的压力来防止车轮被完全抱死的功能，又有防止轮胎在滑的路面上行驶或紧急停车时的滑动。
防抱死制动系统最早应用在航空飞行器上，而且在二十世纪90年代一些国内的汽车内也安装了这种系统。近来，几个汽车制造商引进了更为复杂的防抱死系统。欧洲使用这种系统已有几十年的时间，通过对其的调查，一位汽车制造商坦言，如果所有的汽车都安装上防抱死制动系统，那么交
通事故的发生率会降低7.5%。同时，一些权威人士预测这种系统会提高汽车的安全性。
防抱死制动系统可以在一秒钟内调节几次制动时车轮上的受力，使车轮的滑移受到控制，而且所有的系统基本上都以相同的方式完成。每个车轮都会有一个传感器，电子控制装置能连续检测来自车轮传感器传来的脉冲电信号，并将它们处理转换成和轮速成正比的数值；如果其中一个传感器的信号不断下降，那么这就表明了相应的轮胎趋于抱死，这时电子控制装置向该车轮的制动器发出降低压力的指令。当信号显示车轮转速恢复正常时，电子控制装置会增加制动器的液压。这种循环像司机一样调节制动器，但它的速度更快，达到了每秒循环数次。
防抱死制动系统除了上面基本操作，还有两个特点。首先，当制动系统的压力上升到使轮胎抱死或即将抱死的时候，防抱死制动系统才会启动；当制动系统在正常情况下，防抱死制动系统停止运作。其次，如果防抱死制动系统有问题时，制动器会独立地继续运行。但控制板上的指示灯亮起提醒司机系统出现问题。
目前欧洲汽车生产商，如：宝马、奔驰、宝时捷等广泛使用的是波许（Bosch）防抱死制动系统。这种系统基本组成包括车轮转速传感器，电子控制装置和调节装置。
每个有一个向电子控制装置发出车轮转动情况的信号的传感器，它一般由磁感应传感头和齿圈组成。前面的传感器安在轮毂上，齿圈安在轮网上。后面的传感器安在后部的监测系统上，齿圈安在轮轴上。传感器本身是缠绕电磁核的电线圈，电磁核才线圈的周围产生磁场。当齿圈的齿移动到磁
场时，就会改变线圈的电流。电子控制装置会监测这种变化，然后判断车轮是否即将抱死。
电子控制装置有三个作用，即：信号的处理，编辑和安全防护。信号的处理起到转换器的作用，它是将接受的脉冲电信号处理转换成数值，为编辑做准备。编辑就是分析这些数值，计算出需要制动压力。如果检测出车轮即将抱死，电控装置就会计算出数值向调节装置发出指令。
调节装置
当接受到电子控制装置的指令后，液压执行装置会调节制动轮缸的液压的大小。调节装置能保持或减小来自制动主缸的液压，而装置本身是不能启用制动器的。这种装置有三个高速率的电磁阀，两个油液存储器和一个带有内外检测阀的传动泵。调节装置中的电子连接器隐藏在塑料盖下。
每个电磁阀都是其独立控制的，并作用于前轮。后部的制动轮缸受到一个电磁阀控制，并依照------的原理进行调节。当防抱死制动系统运行时，电子控制装置会使电磁阀循环运作，这样既能收回又能释放制动器的压力。当压力释放时，它会释放到液压单元。前部的制动器电路有一个单元。存储器低压存储器，它在低压下存储油液，直到回流泵打开，油液流经制动轮缸进入制动主缸。
Counter bored hole 沉孔 Chamfer 倒斜角 Fillet 倒圆角 padding block垫块 stepping bar垫条 upper die base上模座 lower die base下模座 upper supporting blank上承板 upper padding plate blank上垫板 spare dies模具备品 spring 弹簧 bolt螺栓 document folder活页夹 file folder资料夹 to put file in order整理资料 spare tools location手工备品仓 first count初盘人 first check初盘复棹人 second count 复盘人 second check复盘复核人 equipment设备 waste materials废料 work in progress product在制品 casing = containerization装箱 quantity of physical inventory second count 复盘点数量 Quantity of customs count 会计师盘,点数量 the first page第一联 filed by accounting department for reference会计部存查 end-user/using unit(department)使用单位 Summary of year-end physical inventory bills 年终盘点截止单据汇总表 bill name单据名称 This sheet and physical inventory list will be sent to accounting department together (Those of NHK will be sent to financial department) 本表请与盘点清册一起送会计部－(NHK厂区送财会部) Application status records of year-end physical inventory List and physical inventory card 年终盘点卡与清册使用－状况明细表 blank and waste sheet NO. 空白与作废单号
中等分辨率制备分离的 快速色谱技术 W. Clark Still,* Michael K a h n , and Abhijit Mitra Departm(7nt o/ Chemistry, Columbia Uniuersity,1Veu York, Neu; York 10027 ReceiLied January 26, 1978 我们希望找到一种简单的吸附色谱技术用于有机化合物的常规净化。这种技术是适于传统的有机物大规模制备分离，该技术需使用长柱色谱法。尽管这种技术得到的效果非常好，但是其需要消耗大量的时间，并且由于频带拖尾经常出现低复原率。当分离的样本剂量大于1或者2g时，这些问题显得更加突出。近年来，几种制备系统已经进行了改进，能将分离时间减少到1-3h，并允许各成分的分辨率ΔR f≥（使用薄层色谱分析进行分析）。在这些方法中，在我们的实验室中，媒介压力色谱法1和短柱色谱法2是最成功的。最近，我们发现一种可以将分离速度大幅度提升的技术，可用于反应产物的常规提纯，我们将这种技术称为急骤色谱法。虽然这种技术的分辨率只是中等（ΔR f≥），而且构建这个系统花费非常低，并且能在10-15min内分离重量在的样本。4 急骤色谱法是以空气压力驱动的混合介质压力以及短柱色谱法为基础，专门针对快速分离，介质压力以及短柱色谱已经进行了优化。优化实验是在一组标准条件5下进行的，优化实验使用苯甲醇作为样本，放在一个20mm*5in.的硅胶柱60内，使用Tracor 970紫外检测器监测圆柱的输出。分辨率通过持续时间（r）和峰宽（w,w/2）的比率进行测定的（Figure 1），结果如图2-4所示，图2-4分别放映分辨率随着硅胶颗粒大小、洗脱液流速和样本大小的变化。
外文翻译 英文原文 Belt Conveying Systems Development of driving system Among the methods of material conveying employed，belt conveyors play a very important part in the reliable carrying of material over long distances at competitive cost．Conveyor systems have become larger and more complex and drive systems have also been going through a process of evolution and will continue to do so．Nowadays，bigger belts require more power and have brought the need for larger individual drives as well as multiple drives such as 3 drives of 750 kW for one belt(this is the case for the conveyor drives in Chengzhuang Mine)．The ability to control drive acceleration torque is critical to belt conveyors’performance．An efficient drive system should be able to provide smooth，soft starts while maintaining belt tensions within the specified safe limits．For load sharing on multiple drives．torque and speed control are also important considerations in the drive system’s design. Due to the advances in conveyor drive control technology，at present many more reliable．Cost-effective and performance-driven conveyor drive systems covering a wide range of power are available for customers’ choices[1]. 1 Analysis on conveyor drive technologies 1．1 Direct drives Full-voltage starters．With a full-voltage starter design，the conveyor head shaft is direct-coupled to the motor through the gear drive．Direct full-voltage starters are adequate for relatively low-power, simple-profile conveyors．With direct fu11-voltage starters．no control is provided for various conveyor loads and．depending on the ratio between fu11-and no-1oad power requirements，empty starting times can be three or four times faster than full load．The maintenance-free starting system is simple，low-cost and very reliable．However, they cannot control starting torque and maximum stall torque；therefore．they are
机械设计 摘要：机器是由机械装置和其它组件组成的。它是一种用来转换或传递能量的装置，例如：发动机、涡轮机、车辆、起重机、印刷机、洗衣机、照相机和摄影机等。许多原则和设计方法不但适用于机器的设计，也适用于非机器的设计。术语中的“机械装置设计”的含义要比“机械设计”的含义更为广泛一些，机械装置设计包括机械设计。在分析运动及设计结构时，要把产品外型以及以后的保养也要考虑在机械设计中。在机械工程领域中，以及其它工程领域中，所有这些都需要机械设备，比如：开关、凸轮、阀门、船舶以及搅拌机等。 关键词：设计流程设计规则机械设计 设计流程 设计开始之前就要想到机器的实际性，现存的机器需要在耐用性、效率、重量、速度，或者成本上得到改善。新的机器必需具有以前机器所能执行的功能。 在设计的初始阶段，应该允许设计人员充分发挥创造性，不要受到任何约束。即使产生了许多不切实际的想法，也会在设计的早期，即在绘制图纸之前被改正掉。只有这样，才不致于阻断创新的思路。通常,还要提出几套设计方案，然后加以比较。很有可能在这个计划最后决定中,使用了某些不在计划之内的一些设想。 一般的当外型特点和组件部分的尺寸特点分析得透彻时，就可以全面的设计和分析。接着还要客观的分析机器性能的优越性，以及它的安全、重量、耐用性，并且竞争力的成本也要考虑在分析结果之内。每一个至关重要的部分要优化它的比例和尺寸，同时也要保持与其它组成部分相协调。 也要选择原材料和处理原材料的方法。通过力学原理来分析和实现这些重要的特性，如那些静态反应的能量和摩擦力的最佳利用，像动力惯性、加速动力和能量；包括弹性材料的强度、应力和刚度等材料的物理特性，以及流体润滑和驱动器的流体力学。设计的过程是重复和合作的过程，无论是正式或非正式的进行，对设计者来说每个阶段都很重要。 最后，以图样为设计的标准，并建立将来的模型。如果它的测试是符合事先要
陶瓷 ceramics 合成纤维 synthetic fibre 电化学腐蚀 electrochemical corrosion 车架 automotive chassis 悬架 suspension 转向器 redirector 变速器 speed changer 板料冲压 sheet metal parts 孔加工 spot facing machining 车间 workshop 工程技术人员 engineer 气动夹紧 pneuma lock 数学模型 mathematical model 画法几何 descriptive geometry 机械制图 Mechanical drawing 投影 projection 视图 view 剖视图 profile chart 标准件 standard component 零件图 part drawing 装配图 assembly drawing 尺寸标注 size marking
技术要求 technical requirements 刚度 rigidity 内力 internal force 位移 displacement 截面 section 疲劳极限 fatigue limit 断裂 fracture 塑性变形 plastic distortion 脆性材料 brittleness material 刚度准则 rigidity criterion 垫圈 washer 垫片 spacer 直齿圆柱齿轮 straight toothed spur gear 斜齿圆柱齿轮 helical-spur gear 直齿锥齿轮 straight bevel gear 运动简图 kinematic sketch 齿轮齿条 pinion and rack 蜗杆蜗轮 worm and worm gear 虚约束 passive constraint 曲柄 crank 摇杆 racker 凸轮 cams
New technique of the computer network Abstract The 21 century is an ages of the information economy, being the computer network technique of representative techniques this ages, will be at very fast speed develop soon in continuously creatively, and will go deep into the people's work, life and study. Therefore, control this technique and then seem to be more to deliver the importance. Now I mainly introduce the new technique of a few networks in actuality live of application. keywords Internet Network System Digital Certificates Grid Storage 1. Foreword Internet turns 36, still a work in progress Thirty-six years after computer scientists at UCLA linked two bulky computers using a 15-foot gray cable, testing a new way for exchanging data over networks, what would ultimately become the Internet remains a work in progress. University researchers are experimenting with ways to increase its capacity and speed. Programmers are trying to imbue Web pages with intelligence. And work is underway to re-engineer the network to reduce Spam (junk mail) and security troubles. All the while threats loom: Critics warn that commercial, legal and political pressures could hinder the types of innovations that made the Internet what it is today. Stephen Crocker and Vinton Cerf were among the graduate students who joined UCLA professor Len Klein rock in an engineering lab on Sept. 2, 1969, as bits of meaningless test data flowed silently between the two computers. By January, three other "nodes" joined the fledgling network.
Manufacturing Engineering and Technology—Machining Serope kalpakjian；Steven R.Schmid 机械工业出版社2004年3月第1版 20.9 MACHINABILITY The machinability of a material usually defined in terms of four factors: 1、Surface finish and integrity of the machined part; 2、Tool life obtained; 3、Force and power requirements; 4、Chip control. Thus, good machinability good surface finish and integrity, long tool life, and low force And power requirements. As for chip control, long and thin (stringy) cured chips, if not broken up, can severely interfere with the cutting operation by becoming entangled in the cutting zone. Because of the complex nature of cutting operations, it is difficult to establish relationships that quantitatively define the machinability of a material. In manufacturing plants, tool life and surface roughness are generally considered to be the most important factors in machinability. Although not used much any more, approximate machinability ratings are available in the example below. 20.9.1 Machinability Of Steels Because steels are among the most important engineering materials (as noted in Chapter 5), their machinability has been studied extensively. The machinability of steels has been mainly improved by adding lead and sulfur to obtain so-called free-machining steels. Resulfurized and Rephosphorized steels. Sulfur in steels forms manganese sulfide inclusions (second-phase particles), which act as stress raisers in the primary shear zone. As a result, the chips produced break up easily and are small; this improves machinability. The size, shape, distribution, and concentration of these inclusions significantly influence machinability. Elements such as tellurium and selenium, which are both chemically similar to sulfur, act as inclusion modifiers in
英文原文出自《Advanced Technology Libraries》2008年第5期 Robot Robot is a type of mechantronics equipment which synthesizes the last research achievement of engine and precision engine, micro-electronics and computer, automation control and drive, sensor and message dispose and artificial intelligence and so on. With the development of economic and the demand for automation control, robot technology is developed quickly and all types of the robots products are come into being. The practicality use of robot products not only solves the problems which are difficult to operate for human being, but also advances the industrial automation program. At present, the research and development of robot involves several kinds of technology and the robot system configuration is so complex that the cost at large is high which to a certain extent limit the robot abroad use. To development economic practicality and high reliability robot system will be value to robot social application and economy development. With the rapid progress with the control economy and expanding of the modern cities, the let of sewage is increasing quickly: With the development of modern technology and the enhancement of consciousness about environment reserve, more and more people realized the importance and urgent of sewage disposal. Active bacteria method is an effective technique for sewage disposal，The lacunaris plastic is an effective basement for active bacteria adhesion for sewage disposal. The abundance requirement for lacunaris plastic makes it is a consequent for the plastic producing with automation and high productivity. Therefore, it is very necessary to design a manipulator that can automatically fulfill the plastic holding. With the analysis of the problems in the design of the plastic holding manipulator and synthesizing the robot research and development condition in recent years, a economic scheme is concluded on the basis of the analysis of mechanical configuration, transform system, drive device and control system and guided by the idea of the characteristic and complex of mechanical configuration,
英文翻译 A comprehensive overview of substations Along with the economic development and the modern industry developments of quick rising, the design of the power supply system become more and more completely and system. Because the quickly increase electricity of factories, it also increases seriously to the dependable index of the economic condition, power supply in quantity. Therefore they need the higher and more perfect request to the power supply. Whether Design reasonable, not only affect directly the base investment and circulate the expenses with have the metal depletion in colour metal, but also will reflect the dependable in power supply and the safe in many facts. In a word, it is close with the economic performance and the safety of the people. The substation is an importance part of the electric power system, it is consisted of the electric appliances equipments and the Transmission and the Distribution. It obtains the electric power from the electric power system, through its function of transformation and assign, transport and safety. Then transport the power to every place with safe, dependable, and economical. As an important part of power’s transport and control, the transformer substation must change the mode of the traditional design and control, then can adapt to the modern electric power system, the development of modern industry and the of trend of the society life. Electric power industry is one of the foundations of national industry and national economic development to industry, it is a coal, oil, natural gas, hydropower, nuclear power, wind power and other energy conversion into electrical energy of the secondary energy industry, it for the other departments of the national economy fast and stable development of the provision of adequate power, and its level of development is a reflection of the country's economic development an important indicator of the level. As the power in the industry and the importance of the national economy, electricity transmission and distribution of electric energy used in these areas is an indispensable component.。Therefore, power transmission and distribution is critical. Substation is to enable superior power plant power plants or power after adjustments to the lower load of books is an important part of power transmission. Operation of its functions, the capacity of a direct impact on the size of the lower load power, thereby affecting the industrial production and power consumption.Substation system if a link failure, the system will protect the part of action. May result in power outages and so on, to the production and living a great disadvantage. Therefore, the substation in the electric power system for the protection of electricity reliability,
机械专业英语词汇中英文对照翻译一览表 陶瓷ceramics 合成纤维synthetic fibre 电化学腐蚀electrochemical corrosion 车架automotive chassis 悬架suspension 转向器redirector 变速器speed changer 板料冲压sheet metal parts 孔加工spot facing machining 车间workshop 工程技术人员engineer 气动夹紧pneuma lock 数学模型mathematical model 画法几何descriptive geometry 机械制图Mechanical drawing 投影projection 视图view 剖视图profile chart 标准件standard component 零件图part drawing 装配图assembly drawing
尺寸标注size marking 技术要求technical requirements 刚度rigidity 内力internal force 位移displacement 截面section 疲劳极限fatigue limit 断裂fracture 塑性变形plastic distortion 脆性材料brittleness material 刚度准则rigidity criterion 垫圈washer 垫片spacer 直齿圆柱齿轮straight toothed spur gear 斜齿圆柱齿轮helical-spur gear 直齿锥齿轮straight bevel gear 运动简图kinematic sketch 齿轮齿条pinion and rack 蜗杆蜗轮worm and worm gear 虚约束passive constraint 曲柄crank 摇杆racker
机械专业相关词汇中英文翻译大全 单价unit price 工日合计Man-day total/work-day total 人工费cost of labor 材料费materials expenses 机械的mechanical 检查接线connection test 发电机generator 调相机phase regulator 周波cycle 减负荷装置 load-shedding equipment 断路器柜circuit breaker cabinet 单母线single busbar 互感器transformer 每相电流Current by Phase 封闭式插接close type socket joint 发电机控制面板generator control panel 分级卸载sorted unloading 同步控制synchronization control 调速器 speed governor 信号屏signal screen 继电器relay 高压柜high pressure cabinet 油浸电力变压器oil-immersed power transformer 空气断路器air circuit breaker 控制屏control panel 直流馈电屏direct current feed control panel 电容器electric condenser 计量盘metering panel 成套配电箱whole set of distribution box 落地式floor model 控制开关Control switches 铜芯电力电缆Copper core power cable 控制电缆actuating cable 热缩式电力电缆终端头pyrocondensation power cable terminal 钢结构支架配管steel structure bracket tubing 万用槽钢versatile U-steel 电缆托架 cable bracket 钢制托盘式桥架steel Tray-type cable support system waterproof socket 防水插座 防爆插座Explosion-proof socket 接地绞线earthing twisted pair 接地母线 earthing bus
第一篇： 航空博物馆与航空展示公园 巴特罗米耶杰·基谢列夫斯基 飞翔的概念、场所的精神、老机场的建筑---克拉科夫新航空博物馆理性地吸取了这些元素，并将它们整合到一座建筑当中。Rakowice-Czyzyny机场之前的旧飞机修理库为新建筑的平面和高度设定了模数比例。在此基本形态上进一步发展，如同裁切和折叠一架纸飞机，生成了一座巨大的建筑。其三角形机翼是由混凝土制成，却如同风动螺旋桨一样轻盈。这个机翼宽大通透，向各个方向开敞。它们的形态与组织都是依据内部功能来设计的。机翼部分为3个不平衡的平面，使内外景观在不断变化中形成空间的延续性，并且联系了建筑内的视觉焦点和室外的展览区。 新航空展示公园的设计连接了博物馆的8栋建筑和户外展览区，并与历史体验建立联系。从前的视觉轴线与通道得到尊重，旧的道路得到了完善，朝向飞机场和跑道的空间被限定出来。每栋建筑展示了一个主题或是一段飞行史。建筑周围伸展出巨大的平台，为特殊主题的室外展览提供了空间。博物馆容纳了超过150架飞机、引擎、飞行复制品、成套的技术档案和历史图片。这里的特色收藏是飞机起源开始的各种飞行器，如Jatho1903、Grade1909、莱特兄弟1909年的飞机模型和1911年的鸽式单翼机。 The first passage: Museum for aviation and aviation exhibition park Bartiomiej Kislelewski The idea of flying, the spirit of place, the structure of the historic airfield – the new Museum of Aviation in Krakow takes up these references intellectually and synthesizes them into a building. The old hangars of the former airport Rakowice Czyzyny set the modular scale for the footprint and the height of the new building. Developed from this basic shape, as if cut out and folded like a paper airplane, a large structure has been generated, with triangular wings made of concrete and yet as light as a wind-vane propeller. The wings are generously glazed and open in all directions. Their form and arrangement depend on the interior uses. In the floor plans of the wings, the three offset
机械工业出版社2004年3月第1版 20.9 MACHINABILITY The machinability of a material usually defined in terms of four factors: 1、Surface finish and integrity of the machined part; 2、Tool life obtained; 3、Force and power requirements; 4、Chip control. Thus, good machinability good surface finish and integrity, long tool life, and low force And power requirements. As for chip control, long and thin (stringy) cured chips, if not broken up, can severely interfere with the cutting operation by becoming entangled in the cutting zone. Because of the complex nature of cutting operations, it is difficult to establish relationships that quantitatively define the machinability of a material. In manufacturing plants, tool life and surface roughness are generally considered to be the most important factors in machinability. Although not used much any more, approximate machinability ratings are available in the example below. 20.9.1 Machinability Of Steels Because steels are among the most important engineering materials (as noted in Chapter 5), their machinability has been studied extensively. The machinability of steels has been mainly improved by adding lead and sulfur to obtain so-called free-machining steels. Resulfurized and Rephosphorized steels. Sulfur in steels forms manganese sulfide inclusions (second-phase particles), which act as stress raisers in the primary shear zone. As a result, the chips produced break up easily and are small; this improves machinability. The size, shape, distribution, and concentration of these inclusions significantly influence machinability. Elements such as tellurium and selenium, which are both chemically similar to sulfur, act as inclusion modifiers in resulfurized steels. Phosphorus in steels has two major effects. It strengthens the ferrite, causing