汽车专业英语(宋进桂)Chapter4

1、Chapter 4 Steering and Suspension Systems 4.1 Steering System4.1.1 Basic Parts of Steering System 4.1.1 Basic Parts of Steering System 4.1.2 Types of Steering System 4.1.2 Types of Steering System 4.1.3 Power Steering Systems 4.1.3 Power Steering Systems 4.2 Suspension Systems 4.2.1 Basic Parts of S

2、uspension System 4.2.1 Basic Parts of Suspension System 4.2.2 Front suspension 4.2.2 Front suspension 4.2.3 Rear Suspension 4.2.3 Rear Suspension Chapter 4 Steering and Suspension Systems4.1 Steering System New Wordsspindlespindln.主轴，心轴，转向节主轴，心轴，转向节linkagelikidn.连接，连接装置，联动装置，传连接，连接装置，联动装置，传动装置动装置plu

3、ngerplndn.活塞，柱塞，活动铁芯活塞，柱塞，活动铁芯rotaryrutria.旋转的，转动的旋转的，转动的speedometerspidmit n.(指汽车的指汽车的)车速表，里程计车速表，里程计relevantrelivnta.有关的，切题的，恰当的有关的，切题的，恰当的 Chapter 4 Steering and Suspension Systems4.1 Steering System The steering system is designed to allow the driver to move the front wheels to the right or left

4、 with a minimum of effort and without excessive movement of the steering wheel. Although the driver can move the wheels easily, road shocks are not transmitted to the driver.4.1.1 Basic Parts of Steering System The basic steering system (Figure 4-1) can be divided into three main assemblies: The spi

5、ndle and steering arm assemblies. The linkage assembly connecting the steering arms and steering gear. The steering wheel, steering shaft, and steering gear assembly. Chapter 4 Steering and Suspension Systems4.1 Steering SystemFigure 4-1 Basic parts of steering system Chapter 4 Steering and Suspensi

6、on Systems4.1 Steering System4.1.2 Types of Steering System There are two types of steering systems: manual steering and manual steering and power steering systems. In the manual steering systems, driver does power steering systems. In the manual steering systems, driver does all the work of turning

7、 the steering wheel, steering gear, and tires. all the work of turning the steering wheel, steering gear, and tires. In the power steering systems, hydraulic or electric power-In the power steering systems, hydraulic or electric power-assisted steering is used to reduce the effort required by turnin

8、g assisted steering is used to reduce the effort required by turning the steering wheel. the steering wheel. There are three types of the steering gears in use: recirculatingrecirculating ball steering gear, worm-and-roller steering gear and rack-and-ball steering gear, worm-and-roller steering gear

9、 and rack-and-pinion steering gear.pinion steering gear.4.1.3 Power Steering Systems Hydraulic lack-and-pinion power steering system Hydraulic lack-and-pinion power steering system. This system . This system consists of mechanical rack-and-pinion steering gear, hydraulic consists of mechanical rack-

10、and-pinion steering gear, hydraulic working cylinders with working plungers, rotary slide valve, oil working cylinders with working plungers, rotary slide valve, oil pump, pressure-limiting valve and oil reservoir (Figure 4-2).pump, pressure-limiting valve and oil reservoir (Figure 4-2). Chapter 4 S

11、teering and Suspension Systems4.1 Steering SystemFigure 4-2 A hydraulic rack-and-pinion power steering system with rotary slide valve Chapter 4 Steering and Suspension Systems4.1 Steering SystemElectro-hydraulic power steering system-Servotronic. Servotronic is an electronically controlled rack-and-

12、pinion steering system in which the hydraulic assisting forces are influenced by the driving speed. At low driving speeds, the full assisting force of the hydraulic rack-and pinion steering takes effect. The hydraulic assisting force is reduced as driving speed increases. So, Servotronic is a speed-

13、sensitive power steering. Servotronic consists of electronic speedometer, ECU, hydraulic rack-and-pinion steering gear, oil reservoir, electro-hydraulic converter and oil pump (Figure 4-3). Chapter 4 Steering and Suspension Systems4.1 Steering SystemFigure 4-3 Servotronic-a electro-hydraulic power s

14、teering system Chapter 4 Steering and Suspension Systems4.1 Steering System Electric power steering-Servolectric. With Servolectric (Figure 4-4), the assisting force is generated by an electronically controlled electric motor. The electric motor is only switched on when required. The steering torque

15、 applied by the driver is measured via a torsion rod with a torque sensor and in addition the speed is measured via a speed sensor. The two signals are fed to the ECU. The ECU calculates the torque required and its force-transfer direction using stored program maps and sends the relevant output sign

16、als to the electric motor. The latter generates an assisting torque which is transformed by a worm-gear pair and transmitted to the rack and-pinion steering gear. Chapter 4 Steering and Suspension Systems4.1 Steering SystemFigure 4-4 Servolectric- a electric power steering systemChapter 4 Steering a

17、nd Suspension Systems4.2 Suspension Systems New Wordsbumpbmpn.碰撞，碰撞，(因碰撞而起的因碰撞而起的)肿块，肿块，(路面路面的的)凸块凸块twisttwistv扭转，扭弯，旋转，捻，搓扭转，扭弯，旋转，捻，搓rebound,ribaundv.弹回，回弹，跳回弹回，回弹，跳回diminishdiminiv.减少，减小，缩减减少，减小，缩减attenuatetenjueitv.变薄，变细，变小，减弱变薄，变细，变小，减弱oscillationsilein n.振动，摆动，波动，振荡振动，摆动，波动，振荡strutstrtn.支柱，支杆，

18、支撑支柱，支杆，支撑transversetrnsv:s a.横向的横向的 Chapter 4 Steering and Suspension Systems4.2 Suspension Systems If a vehicles axles were bolted directly to its frame or body, every rough spot on the road would transmit a force throughout the vehicle. Riding would be uncomfortable, and handling at freeway speed

19、s would be impossible. 4.2.1 Basic Parts of Suspension System Springs. Every vehicle has springs 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 v

20、ehicle. 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. Chapter 4 Steering and Suspension

21、 Systems 4.2 Suspension Systems In so doing, it will rebound, causing the body of the vehicle to In so doing, it will rebound, causing the body of the vehicle to be lifted. The weight of the vehicle then pushes the spring down be lifted. The weight of the vehicle then pushes the spring down after th

22、e spring rebounds. This causes the spring to rebound after the spring rebounds. This causes the spring to rebound again. This process, called spring oscillation, gradually again. This process, called spring oscillation, gradually diminishes until the vehicle is finally still. Spring diminishes until

23、 the vehicle is finally still. Spring oscillation can affect handling and ride quality and must be oscillation can affect handling and ride quality and must be controlled. Shock absorbers are used to attenuate the controlled. Shock absorbers are used to attenuate the oscillation.oscillation. Control

24、 Arms. Control Arms. All vehicles have either control arms or All vehicles have either control arms or struts to keep the wheel assembly in the proper position. The struts to keep the wheel assembly in the proper position. The control arms and struts allow the wheel to move up and down control arms

25、and struts allow the wheel to move up and down while preventing it from moving in any other direction.while preventing it from moving in any other direction. Chapter 4 Steering and Suspension Systems 4.2 Suspension Systems 4.2.2 Front suspension 4.2.2 Front suspension 前悬架前悬架 Almost all modern front

26、suspension systems are independent. Almost all modern front suspension systems are independent. With an independent suspension, each front wheel is free to move With an independent suspension, each front wheel is free to move up and down with a minimum effect on the other wheel. In an up and down wi

27、th a minimum effect on the other wheel. In an independent suspension system, there is also far less twisting independent suspension system, there is also far less twisting motion imposed on the frame than in a system with a solid axle. The motion imposed on the frame than in a system with a solid ax

28、le. The two major types of independent front suspension are the two major types of independent front suspension are the conventional front suspension and the McPherson strut front conventional front suspension and the McPherson strut front suspension.suspension. Conventional Front Suspension. Conven

29、tional Front Suspension. In the conventional front In the conventional front suspension system, one or two control arms are used at each suspension system, one or two control arms are used at each wheel (Figure 4-5). In most systems, the coil springs are mounted wheel (Figure 4-5). In most systems,

30、the coil springs are mounted between the vehicles frame and the lower control arm. In a between the vehicles frame and the lower control arm. In a torsion bar front suspension system (Figure 4-6), the lower arm torsion bar front suspension system (Figure 4-6), the lower arm moves upward, it twists t

31、he torsion bar. moves upward, it twists the torsion bar. Chapter 4 Steering and Suspension Systems4.1 Steering SystemFigure 4-5 A typical independent front suspension Chapter 4 Steering and Suspension Systems4.1 Steering SystemFigure 4-6 A torsion bar front suspension system Chapter 4 Steering and S

32、uspension Systems4.1 Steering System McPherson Strut Front Suspension. Most modern vehicles, especially those with front-wheel drive, use the McPherson strut front suspension systems (Figure 4-7). The entire McPherson strut assembly is attached to the steering knuckle at the lower part of the pedest

33、al. The bottom of the McPherson strut assembly is attached to the single control arm through a ball joint.The advantage of the McPherson strut is its compact design, which allows more room for service on small car bodies. Solid Axle Front Suspension. The use of the solid axle front suspension (or dependent suspension) is generally confined to trucks and off-road vehicles. This system uses a solid dead axle (does not turn with wheels) with a leaf spring at each side. Chapt