2024年6月11日发(作者：圭丹亦)

附 录

附录A

Basic Parts and Types of the Suspension and Steering Systems

Suspension System

If a vehicle's axles were bolted directly to its frame or body, every rough spot in

the road would transmit a jarring force throughout the vehicle. Riding would be

uncomfortable, and handling at freeway speeds would be impossible. The fact that the

modern vehicle rides and handles well is a direct result of a suspension system.

Even though the tires and wheels must follow the road contour, the body should

be influenced as little as possible [1]. The purpose of any suspension system is to

allow the body of the vehicle to travel forward with a minimum amount of

up-and-down movement. The suspension should also permit the vehicle to make turns

without excessive body roll or tire skidding.

Suspension System Components

Vehicle Frame

A vehicle's frame or body must form a rigid structural foundation and

provide solid anchorage points for the suspension system. There are two types of

vehicle construction in common use today: body-over-frame construction, which uses

a separate steel frame to which the body is bolted at various points and unibody

construction, in which the body sections serve as structural members. Unibody

construction is the most common, but body-over-frame construction is still used on

pickup trucks and large cars.

Springs

The springs are the most obvious part of the suspension system. Every

vehicle has a spring of some kind between the frame or body and the axles. There are

three types of springs in general use today: leaf spring, coil spring, and torsion bar.

Two different types of springs can be used on one vehicle. Air springs were once used

in place of the other types of springs, but are now obsolete. Many modern vehicles

have air-operated suspensions, but they are used to supplement the springs.

Shock Absorbers

When the vehicle is traveling forward on a level surface and the wheels

strike a bump, the spring is rapidly compressed (coil springs) or twisted (leaf springs

and torsion bars). The spring will attempt to return to its normal loaded length. In so

doing, it will rebound, causing the body of the vehicle to be lifted. Since the spring

has stored energy, it will rebound past its normal length. The upward movement of the

vehicle also assists in rebounding past the spring's normal length.

The weight of the vehicle then pushes the spring down after the spring rebounds.

The weight of the vehicle will push the spring down, but since the vehicle is traveling

downward, the energy built up by the descending body will push the spring below its

normal loaded height. This causes the spring to rebound again. This process, called

spring oscillation, gradually diminishes until the vehicle is finally still. Spring

oscillation can affect handling and ride quality and must be controlled.

Air Shock Absorbers

Some suspension systems incorporate two adjustable air shock absorbers that are

attached to the rear suspension and connected to an air valve with flexible tubing.

Air operated shock absorbers have hydraulic dampening systems which operate

in the same manner as those on conventional shocks. In addition, they contain a sealed

air chamber, which is acted on by pressure from a height control sensor. Varying the

pressure to the air chamber causes the air shock to increase or decrease its length or

operating range.

Air pressure is delivered to the air shocks through plastic tubing. The tubing

connects the shocks to an air valve. Air pressure for raising the shocks is generally

obtained from an outside source, such as a service station compressor, and is admitted

through the air valve. To deplete the shocks of unwanted air (lower vehicle curb

height), the air valve core is depressed, allowing air to escape.

Control Arms

All vehicles have either control arms or struts to keep the wheel assembly in the

proper position. The control arms and struts allow the wheel to move up and down

while preventing it from moving in any other direction. The wheel will tend to move

in undesirable directions whenever the vehicle is accelerated, braked, or turned.

Vehicle suspensions may have control arms only or a combination of control arms and

struts.

Types of the Suspension

Front Suspension Systems

Almost all modern front suspension systems are independent. With an

2024年6月11日发(作者：圭丹亦)

附 录

附录A

Basic Parts and Types of the Suspension and Steering Systems

Suspension System

If a vehicle's axles were bolted directly to its frame or body, every rough spot in

the road would transmit a jarring force throughout the vehicle. Riding would be

uncomfortable, and handling at freeway speeds would be impossible. The fact that the

modern vehicle rides and handles well is a direct result of a suspension system.

Even though the tires and wheels must follow the road contour, the body should

be influenced as little as possible [1]. The purpose of any suspension system is to

allow the body of the vehicle to travel forward with a minimum amount of

up-and-down movement. The suspension should also permit the vehicle to make turns

without excessive body roll or tire skidding.

Suspension System Components

Vehicle Frame

A vehicle's frame or body must form a rigid structural foundation and

provide solid anchorage points for the suspension system. There are two types of

vehicle construction in common use today: body-over-frame construction, which uses

a separate steel frame to which the body is bolted at various points and unibody

construction, in which the body sections serve as structural members. Unibody

construction is the most common, but body-over-frame construction is still used on

pickup trucks and large cars.

Springs

The springs are the most obvious part of the suspension system. Every

vehicle has a spring of some kind between the frame or body and the axles. There are

three types of springs in general use today: leaf spring, coil spring, and torsion bar.

Two different types of springs can be used on one vehicle. Air springs were once used

in place of the other types of springs, but are now obsolete. Many modern vehicles

have air-operated suspensions, but they are used to supplement the springs.

Shock Absorbers

When the vehicle is traveling forward on a level surface and the wheels

strike a bump, the spring is rapidly compressed (coil springs) or twisted (leaf springs

and torsion bars). The spring will attempt to return to its normal loaded length. In so

doing, it will rebound, causing the body of the vehicle to be lifted. Since the spring

has stored energy, it will rebound past its normal length. The upward movement of the

vehicle also assists in rebounding past the spring's normal length.

The weight of the vehicle then pushes the spring down after the spring rebounds.

The weight of the vehicle will push the spring down, but since the vehicle is traveling

downward, the energy built up by the descending body will push the spring below its

normal loaded height. This causes the spring to rebound again. This process, called

spring oscillation, gradually diminishes until the vehicle is finally still. Spring

oscillation can affect handling and ride quality and must be controlled.

Air Shock Absorbers

Some suspension systems incorporate two adjustable air shock absorbers that are

attached to the rear suspension and connected to an air valve with flexible tubing.

Air operated shock absorbers have hydraulic dampening systems which operate

in the same manner as those on conventional shocks. In addition, they contain a sealed

air chamber, which is acted on by pressure from a height control sensor. Varying the

pressure to the air chamber causes the air shock to increase or decrease its length or

operating range.

Air pressure is delivered to the air shocks through plastic tubing. The tubing

connects the shocks to an air valve. Air pressure for raising the shocks is generally

obtained from an outside source, such as a service station compressor, and is admitted

through the air valve. To deplete the shocks of unwanted air (lower vehicle curb

height), the air valve core is depressed, allowing air to escape.

Control Arms

All vehicles have either control arms or struts to keep the wheel assembly in the

proper position. The control arms and struts allow the wheel to move up and down

while preventing it from moving in any other direction. The wheel will tend to move

in undesirable directions whenever the vehicle is accelerated, braked, or turned.

Vehicle suspensions may have control arms only or a combination of control arms and

struts.

Types of the Suspension

Front Suspension Systems

Almost all modern front suspension systems are independent. With an