汽车设计外文文献翻译、中英文翻译、外文翻译

1 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 1970's. 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.

The machine piston connecting rod set

The piston connecting rod set is composed of the piston, piston wreath, piston pin,

connecting rod, connecting rod axle bush, etc.

effect: The effect of the piston is to bear the air pressure, and pass to connecting rod to

drive the bent axle to revolve through connecting rod axle bush, the piston coping is still a

part of the burning room. The work condition: Piston works under the condition of heat, high

pressure, high speed, and bad lubrication .Piston directly contacts with the heat air. The

temperature can amount to above 2500 Ks in a moment .The piston is heated severely, but the

condition of spreading the hot is bad .So while the piston works, the temperature is very high

and the coping is up to the 600-700 Ks: And the temperature distributes asymmetrically; The

piston coping bears great air pressure, especially the pressure is greatest in the route of doing

efficacy. The gasoline machine is up to the 3-5MPas, the diesel engine is up to the 2 6-9MPas.This makes the piston produce pound, and bear the function of the side pressure.

Therefore, the piston should have enough heat-proof, try to decrease the heating area,,

strengthen the cooling of the piston, to make the highest temperature of the coping

descend .The piston moves at very high speed(8-12 ms/ s) back and forth in the air cylinder,

and speed changes constantly, This produces very great inertial dint, making the piston bear

great additional load working under such bad condition, the piston will become deformed

heating power. At the same time ,it slitters the chemical corrosive power of the burning

gas .In order to descend the inertial dint of back and forth, we must ease the weight of the

piston as possible .Piston works under the condition of the heat, high pressure, high speed(the

average speed can amount to the 101115 m/ s), and its lubricant condition is bad and the

frication between the piston and the air cylinder wall is very great. In order to descend the

friction, the surface of the piston surface must be wear-resistant..