外文翻译--汽车设计-车架设计VIP

附录 Automobile Design-Frame Designs The vehicle frame is the basic platform to which all suspension and steering linkage parts attach. A vehicle will neither steer nor handle well if the frame is too flexible. A rigid frame structure may pass unnecessary vibrations into the passenger compartment. The frame and suspension design will affect the ride quality, handling, and durability, as well as the levels of both noise and vibration. Manufacturers use several different types of construction on their vehicles. Of these, separate body and frame construction was the most common through the 1970s. It is still used in large vans, pickups, and trucks. In this type of construction, the engine, drive line, running gear, and body mount to the frame through insulators. Insulators are synthetic rubber pads that keep road and engine noise and vibration from going into the passenger compartment. A second type of construction is the unitized body. This, design is by far the most popular in modern vehicles. The unitized design has a lightweight structure with the required strength. Tn this type of construction, the frame is welded into the body as part of the body structure. Body panels add strength to the frame pieces. The running gear and drive line are mounted to the unitized body through large, soft synthetic rubber insulators. The insulators minimize the transfer of noise and vibration. If the insulators are too soft, they will allow too much running gear and drive line movement. This movement, called compliance, affects vehicle handling and control. If the insulators are too hard, they will not insulate noise and vibration as they should. The manufacturer carefully designs the insulators and puts them where they will be in a vehicle with low noise and vibration transmission that still has proper handling and feel. Insulator properties change with age, changing original characteristics as the vehicle becomes older. A third type of construction combines the features of the first and second types. It uses a stub frame from the bulkhead forward and a unitized body from the bulkhead back. The unitized part is very rigid, while the stub frame provides a place for good insulation. Manufacturers select the type of construction .that is most economical to build, while providing the noise, vibration, and ride and handling characteristics they want in the vehicle. Large older vehicles, vans, and trucks generally use separate body and frame construction. The newer, smaller vehicles generally use unitized construction. 汽车设计 -车架设计 车架是汽车最基本的台架，所有的悬架和转向连接部件都安装在车架上面。如果汽车车架柔性过大，会使汽车既无法转向，也无法进行正常操纵。而如果汽车车架结构刚性过大，又会引起不必要的震动传递给驾驶员和乘客的座舱室。汽车车架和悬架的结构设计不仅决定了汽车噪声大小和震动的幅度强度，而且也将影响到汽车的质量和车辆的正常操纵。 汽车制造厂商们在他们生产的汽车上都使用了几种不同的车架结构。其中，整个七十年代最常使用的是壳体和大梁的分体结构。目前它仍然在大型货车、小吨位货车和卡车上应用着。在汽车壳体和大梁的分体结构里， 发动机、传动装置、传动齿轮和车壳都是通过绝缘装置固定在车身大梁上。车架内部的绝缘装置是人造橡胶缓冲垫，能够阻止道路不平和发动机工作引起的噪音和震动传到驾驶员和乘客的座舱里。 第二种是汽车车架的单体结构。这种设计到目前为止在现代汽车上是最常用。单体车架按所需的强度来分，设计有轻型结构。在这种汽车结构中大梁作为车架的一部分被直接焊接到壳体上。底盘的重量增加了大梁的强度。传动齿轮和传动装置经由大而软的人造橡胶绝缘垫安装在单体车架上。绝缘垫减弱了噪声的传动和震动。若绝缘垫太软，将会引起传动齿轮和传动装置位移。这种位 移称为柔量，它会影响到汽车的操纵性能和控制性能。若绝缘垫太硬，则不能起到应有的隔绝噪音和减小震动的作用。汽车制造厂商们精心地设计绝缘垫，把它们装置在汽车适当的地方，以降低噪声，缓冲震动的传送，使汽车便于驾驶，驾驶员和乘客乘坐舒适。绝缘垫的性能随使用年限发生变化，当汽车变旧时原先的性能也随之改变。 第三种结