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# (毕业设计)奔腾B50轿车悬架系统设计毕业论文-正文

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Abstract

Now the development of automobile technology more and more rapidly, people on car comfort requirements are also increasing, and this aspect of performance cars on the need to ensure that suspension system. Based on the current developments in the car suspension, the design of the car before and after the suspension are used in the form of independent suspension. Before the hanging and are used more popular double withbone arm type suspension. According to determine the structure of the selected suspension natural frequency, which can calculate the stiffness of the suspension, static and dynamic deflection deflection. More flexible use of data of components and size of a stress check. In the design of shock absorber, in accordance with the largest damping and unloading of the terms of the main shock absorber selected size. Then bodies were identified and horizontal orientation Wending Gan. In all structure size is determined by CAXA mapping software before and after the suspension of the assembly and parts plans. In the car-like suspension of a ride, a two degree of freedom of the ride analysis model, were drawn body acceleration of the rate of frequency, the relative frequency of dynamic curve, moving spring deflection increase the frequent curve analysis - Parameters on the car ride impact. In this paper, for the work done by Ben Teng B 50 car's suspension system design provide a theoretical basis, the practical application of a certain significance. cy of a hanging

Key words: Car; Suspension;shock absorber ; Ride analysis

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6.1 减振器概述 ............................................................................................. 17 6.2 减振器分类 ............................................................................................. 17 6.3 减振器主要性能参数 ............................................................................. 18 6.3.1 相对阻尼系数确定 ...................................................................... 18 6.3.2 减震器阻尼系数 .......................................................................... 18 6.4 最大卸荷力 ............................................................................................. 19 6.4.1 前悬架的最大卸荷力 .................................................................. 19 6.4.2 后悬架的最大卸荷力 .................................................................. 19 6.5 筒式减振器主要尺寸 ............................................................................. 20 6.5.1 筒式减振器工作直径 .................................................................. 20 6.5.2 油筒直径 ...................................................................................... 21 第七章 平顺性分析 .................................................................................................... 22 7.1 平顺性概念 ............................................................................................. 22 7.2 汽车的等效振动分析 ............................................................................. 22 7.3 车身加速度的幅频特性 .......................................................................... 24 7.4 悬架动挠度的幅频特性 .......................................................................... 25 第八章 结论 ................................................................................................................ 27 参考文献 ........................................................................................................................ 28 附 录 I ............................................................................................................................ 30 附录 II ............................................................................................................................. 42

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2.1 独立悬架结构特点

2.2 独立悬架结构形式及评价指标分析

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2.3 前后悬架结构方案

2.4 辅助元件
2.4.1 横向稳定杆

2.4.2 导向机构

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3.1 主要技术参数

3.2 悬架性能参数确定
1）自振频率（固有频率）选取 轿车自振频率取值范围为 0.7～1.6Hz。对于簧载质量大的车型取值偏向小的 方向，对于簧载质量小的车型取值偏向大的方向。货车自振频率取值范围为 1.5～ 4.0 Hz。CRV 轿车要兼顾轿车和越野车的性能。 因此，前悬架偏频为 1.20Hz，即 n 1 =1.20Hz 后悬架偏频为 1.30Hz，即 n 2 =1.30Hz 2) 悬架刚度 汽车前、后部分车身的自振频率 n 1 和 n 2 （亦称偏频）可用下式表示
n1 ? c 1 / m 1 / (2 ? )

n2 ?

c 2 / m 2 / (2 ? )

（3-1）

2

2

c ? (2 n1? ) m 1 ? (2 ? 1 .2 0 ? 3 .1 4 ) ? 9 0 2 ? 5 1 2 2 5.7 N / m

c1 ? 25612.87 N / m

4

c ? ( 2 n1? ) m 2 ? ( 2 ? 1 .3 0 ? 3 .1 4 ) ? 7 3 8 ? 4 9 1 8 8 .4 N / m
2 2

c 2 ? 2 4 5 9 4 .2 N / m

3.3 悬架静挠度

fc ? g

?2? n ? 2

（3-2）

g 为重力加速度，g＝ 9810 mm / s２
f c1 ? g

?2? n ?
g

2

?

9810

?2 ? ? ?2 ? ?

? 1 .2 ?

2

=172.7mm =147.0 mm

fc2 ?

?2? n ?

2

?

9810 ? 1 . 25 ?
2

3.4 悬架动挠度

f c ? 50 ~ 110 mm f c ? 60 ~ 130 mm f c ? 70 ~ 150 mm f c ? 100 ~ 300 mm f d ? ( 0 .7 ~ 1 .0 ) f c fd ? fc f d ? ( 0 .7 ~ 1 .0 ) f c f d ? ( 0 .5 ~ 0 .7 ) f c f d 2 ? 0.7 f c 2 ? 102.91m m

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.5 悬架弹性特性曲线
1-缓冲块复原点 2-复原行程缓冲块脱离支架 3-主弹簧弹性特性曲线 4-复原行程 5-压缩行程 6-缓冲块压缩期悬架特性曲线 7-缓冲块压缩时开始接触弹性支架 8-额定载荷

3-1 悬架弹性特性曲线

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4.1 前悬架弹簧（麦弗逊悬架）
4.1.1 弹簧中径、钢丝直径及结构形式
Fw

：汽车满载静止时悬架上的载荷

F w ? f c c ? mg

（4-1）

F w ? 902 ? 9.8 ? 8839.6N

D2 d

，设计中一般推荐取 4 ? C ? 6 ，常用的初选范围为 C=5～8

4C ? 1 4C ? 4

?

0 .6 1 5 C

? 1 .2 5 2 5

8 KFC

? ?? ?

（4-2）

d ? 8KFC

? ??

?

? 1 .6

K F w 1C

?? ?

? 1 .6

1 .2 5 ? 4 4 1 9 .8 ? 6 590

? 1 1 .9 9

D=Cd=72mm

D2 3 D2 2

=25～37.5mm

4.1.2 弹簧圈数

4

（4-3）

7

f cs ? 8 F w D i G d
3 4

? 8 ? 4 4 1 9 .8 ? 7 5 ? 6 7 9 ? 1 0 ? 1 2 ? 5 4 .6 m m
3 3 4

?c ? ?

? f cs Gd ? ? 2 ? ? ? c ? ? 500 MPa ?D i ? ?

3 则 ? c ? 5 4 .6 ? 7 9 ? 1 0 ? 1 2

?

? ? 75 ? 6
2

? ? 4 8 8 .4 M P a ? ??

c

?

4.2 后悬架弹簧（双横臂独立悬架）
4.2.1 弹簧中径、钢丝直径及结构形式
Fw

：汽车满载静止时悬架上的载荷

F w ? f c c ? mg

F w ? 738 ? 9.8 ? 7232.4 N

D2 d

，设计中一般推荐取 4 ? C ? 6 ，常用的初选范围为 C=5~8

4C ? 1 4C ? 4

?

0 . 615 C

=1.2525

8 KFC

? ?? ?

（4-4）

d ? 8KFC

? ??

?

? 1 .6

K F w 1C

?? ?

? 1 .6

1 .2 1 ? 3 6 1 6 .2 ? 7 590

? 1 0 .8

D=Cd=72mm

D2 3 D2 2

=25～37.5mm

4.2.2 弹簧圈数

8

?c ? ?
? f cs Gd ? ? 2 ? ? ? c ? ? 500 MPa ?D i ? ?

3 则 ? c ? 4 4 .7 ? 7 9 ? 1 0 ? 1 3

?

? ? 90 ? 6
2

? ? 3 0 0 .6 7 M P a ? ??

c

?

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5.1 导向机构设计要求
1）悬架上载荷变化时，保证轮距变化不超过 ? 4 . 0 mm ，轮距变化大会引起 轮胎早期磨损。 2）悬架上载荷变化时，前轮定位参数有合理的变化特性，车轮不应产生纵 向加速度。 3）汽车转弯行驶时，应使车身侧倾角小。在 0 . 4 g 侧加速度下，车身侧倾角 不大于 6 ?
~ 7
?

，并使车轮与车身的倾斜同向，以增强不足转向效应。

4）汽车制动时，应使车身有抗前俯作用，加速时有抗后仰作用。

5.2 双横臂独立悬架示意图

（1）适用弹簧：螺旋弹簧 （2）主要使用车型：轿车前轮； （3）车轮上下振动时前轮定位的变化：

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（4）轮距、外倾角的变化比稍小； （5）拉杆布置可在某种程度上进行调整。 （6）侧摆刚度：很高、不需稳定器； （7）操纵稳定性： （8）横向刚度高； （9）在某种程度上可由调整外倾角的变化对操纵稳定性进行调整。

5.3 横臂轴线布置方式

5.4 导向机构的布置参数

5.4.1 侧倾中心

h w ? B 1 h P （ k cos ? ? d tan ? ? a ) 2

k ? sin ( 90

0

? ? ? ? ) sin( ? ? ? )

p ? k sin ? ? d

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5-4 双横臂式悬架侧倾中心的确定

5. 4.2 纵倾中心

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5. 4.3 抗制动纵倾性（抗制动前俯角）

5. 4.4 抗驱动纵倾性（抗驱动后仰角）

5. 4.5 悬架横臂的定位角

' ‘ ’

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5.5 横向稳定杆的作用

5.6 横向稳定杆的设计计算

K su 1 2 ?m? ? K sp 1 ? ? ? n ?
2

（5-1）

K sp 1 ? K su 1 ?m ? 2? ? ? n ?
2

?

5 0 9 4 1 .8 ? 300 ? 2?? ? ? 480 ?
2

? 6 5 2 0 5 .5 N / m

K sp 2 ? K su 2 ?m ? 2? ? ? n ?
2

?

4 1 9 8 8 .4 ? 340 ? 2?? ? ? 500 ?
2

? 4 5 4 0 2 .6 8 N / m

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1 1 ? Bm ? ? 1 .5 4 ? 0 .3 0 ? K sp 1 ? ? ? ? 6 5 2 0 5 .5 ? ? ? ? 3 0 2 0 3 .3 9 1 N / m 2 2 0 .4 8 ? n ? ? ?
2 2

K ?1 ?

K?2 ? 1 2 K sp 2 1 ? Bm ? ? 1 .5 4 ? 0 .3 4 ? ? ? ? ? 4 5 4 0 2 .6 8 ? ? ? ? 2 4 8 9 4 .9 2 1 N / m 2 0 .5 ? n ? ? ?
2 2

（5-2）

C ? b ? 1.5 K ? 2 ? K ? 1 ? 1.5 ? 24894.921 ? 30203.391 ? 19586.452 N / m
f ? L ? 3 ? 3 2 2 l1 ? a ? ( a ? b ) ? 4 l2 (b ? c ) ? ? 3 EI ? 2 ? P
5 E－－－材料的弹性模量， E ? 2 . 06 ? 10 MPa

（5-3）

d－－－稳定杆的直径，mm P－－－端点作用力，N f－－－端点位移，mm I－－－稳定杆的截面惯性矩， I ? 前悬架横向稳定杆直径 d：
d ? 128
4

?d
64

4

, mm

4

3? ?

?

C?b ? 3 L ? 3 2 2 2 ? l1 ? a ? 2 ( a ? b ) ? 4 l 2 ( b ? c ) ? L E ? ? 1 9 5 8 6 .4 5 2 1 .0 4 ? ? 3 3 2 2 0 .2 7 ? 0 .1 2 ? (0 .1 2 ? 0 .1 2 ) ? 4 ? 0 .2 4 ? (0 .1 2 ? 0 .2 8) ? ? 2 ? ?

?

128
4

3?

1 .0 4 ? 2 .0 6 ? 1 0
2

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? 2 0 .2 2 m m

? ?

1 6 P L2 K

'

?d
K
'

3

?

1 6 ? 2 3 5 7 ? 0 .2 4 ? 1 .4 7 6

? ? 0 .0 2 0 2

3

? 5 1 5 .9 1 M P a ? ?? ? ? 8 0 0 M P a
? 0 . 615 C ? 4 ? 3 .5 ? 1 4 ? 3 .5 ? 4 ? 0 . 615 3 .5 ? 1 . 476

-----曲度系数， K ' ?

4C ? 1 4C ? 4

C-------弹簧指数， C ? ( 2 R ? d ) / d ? ( 2 ? 1 . 25 d ? d ) / d ? 3 . 5 R 的取值不小于 1.25d 后悬架稳定杆的角刚度 C ? b ? 0 .5 K ? 2 ? 0 .5 ? 2 4 8 9 4 .9 2 ? 1 2 4 4 7 .5 N / m
d ? 128
4

3? ?

?

C?b ? 3 L ? 3 2 2 l ? a ? ( a ? b ) ? 4 l2 (b ? c ) 2 ?1 ? L E ? 2 ? 12447.5

?

128
4

3?

1.04 ? ? 3 3 2 2 0.27 ? 0.12 ? (0.12 ? 0.12) ? 4 ? 0.24 ? (0.12 ? 0.28) ? 18. m m ? ? 1.04 ? 2.06 ? 10 ? 2 ?
2 11

15

? ?
1 6 P L2 K
'

?d

3

?

1 6 ? 1 9 3 1 ? 0 .2 4 ? 1 .4 7 6

? ? 0 .0 1 8

3

? 5 9 7 .3 5 M P a ? ?? ? ? 8 0 0 M P a

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6.1 减振器概述

6.2 减振器分类

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6.3 减振器主要性能参数
6.3.1 相对阻尼系数确定

?

0.5 0.8

? 1Y ? 0 . 5? 1 S ? 0 . 2

? 1Y ? 0 .5? 1 S ? 0 .2

6.3.2 减震器阻尼系数

?
2 C ms

（6-1）

ms

——悬挂部分的质量 （6-2）
2 5 4 7 0 .9 ? 9 0 2 ? 3 8 3 4 .5 6

? 1 s ? 2? 1 s C 1 m 1 ? 2 ? 0 .4 ?

? 1Y ? 2? 1Y
C 1 m 1 ? 2 ? 0 .2 ? 2 5 4 7 0 .9 ? 9 0 2 ? 1 9 1 7 .3

? 2 s ? 2?
2 s

C m ? 2? 0 .?4 2 2

2 4 5 ? 4 . 2? 7 3 8 9

3 4 0 8 .2 8

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? 2 Y ? 2? 2 Y
C 2 m 2 ? 2 ? 0.2 ?
C ms

2459.2 ? 738 ? 1704.14

（6-3）
C1 m1s C2 m2s ? 2 5 4 7 0 .9 902 2 4 5 9 4 .2 738 ? 5 .3

?

? 5 .8

6.4 最大卸荷力
6.4.1 前悬架的最大卸荷力

v x ? A ? a cos ? n

（6-4）

? ：悬架振动固有频率。

a：减振器在下横臂上的连接点到下横臂在车身上的铰接点之间的距离； n：悬架的下臂长； 前悬架为双横臂式独立悬架， 轮距 B=1.54m 最大卸荷力 F0 ? ? s v x 伸张行程时的最大卸荷力 F1 0 ? ? 1 s v1 x ? 3 8 2 3 .9 ? 0 .3 ? 1 1 4 7 .1 7 N 压缩行程时的最大卸荷力 F10 ? ? 1Y v1 x ? 1 .9 1 1 9 ? 0 .3 ? 5 7 3 .5 8 5 N （6-5）

6.4.2 后悬架的最大卸荷力

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6.5 筒式减振器主要尺寸
6.5.1 筒式减振器工作直径

D ? 4 F0

? [ P ]( 1 ? ? )
2

（6-6）

[P]---工作缸内最大允许压力,取 3 ~ 4 MPa
? ---连杆直径与缸筒直径之比,双筒式取 ? ? 0 . 40 ~ 0 . 50

30 40 ( 50 65 的工作缸直径 D 有 20 、 、 、45 )、 、 mm 等几种。

D1 ? 4 F0 ? 4 ? 1 1 4 7 .1 7 ? 0 .0 2 5 m

? ? P ? ?1 ? ?

2

?

? ? 3 ? 1 0 ? ? 1 ? 0 .5
6

2

?

D2 ?

? ? P ? ?1 ? ?

4 F0

2

?

?

4 ? 1 0 2 2 .4 6

? ? 3 ? 1 0 ? ? 1 ? 0 .5
6

2

?

? 0 .0 2 4 m

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6.5.2 油筒直径

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7.1 平顺性概念

7.2 汽车的等效振动分析

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? ? ? M Z? ? c ( Z ? s ) ? k ( Z ? s ) ? 0

? ? m ?? ? c ( Z ? s ) ? k ( Z ? s ) ? k t s ? k t q s

m
k

k ? kt Mm

c

k t 为左右两侧悬架的合成轮胎刚度 ( N m ) ；
Z

s
q

?1 ?
2

1 2

(? t ? ? 0 ) ?
2 2

1 4

(? t ? ? 0 ) ?
2 2 2

?2 ?
2

1 2

(? t ? ? 0 ) ?
2 2

1 4

(? t ? ? 0 ) ?
2 2 2

k ? kt Mm

k M

，? t2 ?

k ? kt m

。由上式可知，汽车振动存在两个主频 ? 1 和 ? 2 ，它们

? ?0

，且接近由弹簧质量和悬架刚度所决定的频率 ? 0 ，

?t 。
? ? ? 方程 M Z? ? c ( Z ? s ) ? k ( Z ? s ) ? 0 的解是由自由振动齐次方程的解与非齐次方程特解

c M

， ? 02 ?

k M

，则奇次方程为
2 ? ? Z? ? 2 b Z ? ? 0 Z ? 0

ζ ? b

?0

?

c 2 Mk

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Z ? Ae
? nt

sin(

? 0 ? b t ? a)
2 2

7.3 车身加速度的幅频特性

ft ? K ? Kt) M 2? c 2 K ? Kt M ? f1

? (1 ? ? ) ? 12 . 9

?t ?

??

? (1 ? ? )

? t 1 ? 2 . 68 （一阶阻尼比）
? t 2 ? 5 . 36 （二阶阻尼比）

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0 . 2 ~ 0 . 4 比较合适。

7.4 悬架动挠度的幅频特性

H ( j? )
fd ~ q

?

fd q

z1 q

?
fd q

A2 K t A3 A 2 ? A
? A1 K t N ?
2 1

?

A2 K t N
?

z2 q

?

z 2 z1 z1 q

?

A1 K t N

A2 K t N
1

K t ( A1 ? A 2 ) N

fd ? q

2 2 ? 1 ? ? ? ? ? ? ?? ?

?

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? 0 . 5 时已不呈现峰值。且阻尼比 ?

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[1] [2] [3] [4] [5] [6] [7] [8] [9] 刘惟信．汽车设计[M].第 5 版．北京:清华大学出版社，2001 余志生主编.汽车理论[M].北京：机械工业出版社，2004 陈家瑞主编.汽车构造[M].北京：人民交通出版社，2004 王望予主编.汽车设计[M].北京：机械工业出版社，2004 龚微寒.汽车现代设计制造[M].北京：人民交通出版社，1995 王 宣 译 悬架元件与底盘力学[M].北京：人民交通出版社，2004 龚微寒.汽车现代设计制造[M].北京:人民交通出版社，1995 赵学敏.汽车底盘构造与维修[Ｊ].国防工业出版社，2003,1 屠卫星.汽车底盘构造与维修[Ｊ].人民交通出版社，2001,8 森.汽车底盘维修实例[M].机械工业出版社，2002

[10] 宋

[11] 嵇伟．新型汽车悬架与车轮定位[M].北京:机械工业出版社，2004 [12] 张金柱主编．悬架系统[M]. 北京：化学工业出版社，2005 [13] John Fenton. Hand Book of Vehicle Design Analysis.Warrendale,PA.,USA:Society of Automo-tive Engineers,Inc[M],1996 [14] Julia Happian-Smisth.An Introduction to Modern Vehicle

Design[M].2006 [15] Yu F., Crolla D.A. A State Observer Design for an Adaptive Vehicle Suspension. Vehicle Suspension Dynamic[M], 1998 [16] Griffin ， M.J. Evaluation of vibration with respect to human response. Warrendale PA: SAE paper [Ｊ]. 860047 [17] Christian Best.Basic Utility Vehicle Suspension Design[M].2002

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Suspension systems
When people think of automobile performance, they normally think of horsepower, torque and zero-to-60 acceleration. But all of the power generated by a piston engine is useless if the driver can't control the car. That's why automobile engineers turned their attention to the suspension system almost as soon as they had mastered the four-stroke internal combustion engine.

Double-wishbone suspension on Honda Accord 2005 Coupe

The job of a car suspension is to maximize the friction between the tires and the road surface, to provide steering stability with good handling and to ensure the comfort of the passengers. In this article, we'll explore how car suspensions work, how they've evolved over the years and where the design of suspensions is headed in the future. If a road were perfectly flat, with no irregularities, suspensions wouldn't be necessary. But roads are far from flat. Even freshly paved highways have subtle imperfections that can interact with the wheels of a car. It's these imperfections that apply forces to the wheels. According to Newton's laws of motion, all forces have both magnitude and direction. A bump in the road causes the wheel to move up and down perpendicular to the road surface. The magnitude, of course, depends on whether the wheel is striking a giant bump or a tiny speck. Without an intervening structure, all of wheel's vertical energy is transferred to the frame, which moves in the same direction. In such a situation, the wheels can lose contact with the road completely. Then, under the downward force of gravity, the wheels can slam back into the road surface. What you need is a system that will absorb the energy of the vertically accelerated wheel,
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allowing the frame and body to ride undisturbed while the wheels follow bumps in the road.

A car's suspension, with its various components, provides all of the solutions described.

Car Suspension Parts
The suspension of a car is actually part of the chassis, which comprises all of the important systems located beneath the car's body. These systems include:
?

The frame - structural, load-carrying component that supports the car's engine and body, which are in turn supported by the suspension

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? ? ?

The suspension system - setup that supports weight, absorbs and dampens shock and helps maintain tire contact The steering system - mechanism that enables the driver to guide and direct the vehicle The tires and wheels - components that make vehicle motion possible by way of grip and/or friction with the road So the suspension is just one of the major systems in any vehicle. With this big-picture overview in mind, it's time to look at the three

fundamental components of any suspension: springs, dampers and anti-sway bars.

Springs Today's springing systems are based on one of four basic designs: Coil springs - This is the most common type of spring and is, in essence, a heavy-duty torsion bar coiled around an axis. Coil springs compress and expand to absorb the motion of the wheels. Leaf springs - This type of spring consists of several layers of metal (called "leaves") bound together to act as a single unit. Leaf springs were first used on horse-drawn carriages and were found on most American automobiles until 1985. They are still used today on most trucks and heavy-duty vehicles.

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Coil springs

Photo courtesy HowStuffWorks Shopper Leaf spring

Torsion bars - Torsion bars use the twisting properties of a steel bar to provide coil-spring-like performance. This is how they work: One end of a bar is anchored to the vehicle frame. The other end is attached to a wishbone, which acts like a lever that moves perpendicular to the torsion bar. When the wheel hits a bump, vertical motion is transferred to the wishbone and then, through the levering action, to the torsion bar. The torsion bar then twists along its axis to provide the spring force. European carmakers used this system extensively, through the 1950s and 1960s.

?

Torsion bar Air springs - Air springs, which consist of a cylindrical chamber of air positioned between the wheel and the car's body, use the compressive qualities of air to absorb wheel vibrations. The concept is actually more than a century old and could be found on horse-drawn buggies. Air springs from this era were made from air-filled, leather diaphragms, much like a bellows; they were replaced with molded-rubber air springs in the 1930s.
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Air springs Based on where springs are located on a car -- i.e., between the wheels and the frame -- engineers often find it convenient to talk about the sprung mass and the unsprung mass. Springs: Sprung and Unsprung Mass The sprung mass is the mass of the vehicle supported on the springs, while the unsprung mass is loosely defined as the mass between the road and the suspension springs. The stiffness of the springs affects how the sprung mass responds while the car is being driven. Loosely sprung cars, such as luxury cars (think Lincoln Town Car), can swallow bumps and provide a super-smooth ride; however, such a car is prone to dive and squat during braking and acceleration and tends to experience body sway or roll during cornering. Tightly sprung cars, such as sports cars (think Mazda Miata), are less forgiving on bumpy roads, but they minimize body motion well, which means they can be driven aggressively, even around corners. So, while springs by themselves seem like simple devices, designing and implementing them on a car to balance passenger comfort with handling is a complex task. And to make matters more complex, springs alone can't provide a perfectly smooth ride. Why? Because springs are great at absorbing energy, but not so good at dissipating it. Other structures, known as dampers, are required to do this.

Dampers: Shock Absorbers
Unless a dampening structure is present, a car spring will extend and release the energy it absorbs from a bump at an uncontrolled rate. The spring will continue to bounce at its natural frequency until all of the energy originally put into it is used up. A

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suspension built on springs alone would make for an extremely bouncy ride and, depending on the terrain, an uncontrollable car. Enter the shock absorber, or snubber, a device that controls unwanted spring motion through a process known as dampening. Shock absorbers slow down and reduce the magnitude of vibratory motions by turning the kinetic energy of suspension movement into heat energy that can be dissipated through hydraulic fluid. To understand how this works, it's best to look inside a shock absorber to see its structure and function.

A shock absorber is basically an oil pump placed between the frame of the car and the wheels. The upper mount of the shock connects to the frame (i.e., the sprung weight), while the lower mount connects to the axle, near the wheel (i.e., the unsprung weight). In a twin-tube design, one of the most common types of shock absorbers, the upper mount is connected to a piston rod, which in turn is connected to a piston, which in turn sits in a tube filled with hydraulic fluid. The inner tube is known as the pressure tube, and the outer tube is known as the reserve tube. The reserve tube stores excess hydraulic fluid. When the car wheel encounters a bump in the road and causes the spring to coil and uncoil, the energy of the spring is transferred to the shock absorber through the upper mount, down through the piston rod and into the piston. Orifices perforate the piston and allow fluid to leak through as the piston moves up and down in the pressure tube. Because the orifices are relatively tiny, only a small amount of fluid, under great

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pressure, passes through. This slows down the piston, which in turn slows down the spring. Shock absorbers work in two cycles -- the compression cycle and the extension cycle. The compression cycle occurs as the piston moves downward, compressing the hydraulic fluid in the chamber below the piston. The extension cycle occurs as the piston moves toward the top of the pressure tube, compressing the fluid in the chamber above the piston. A typical car or light truck will have more resistance during its extension cycle than its compression cycle. With that in mind, the compression cycle controls the motion of the vehicle's unsprung weight, while extension controls the heavier, sprung weight. All modern shock absorbers are velocity-sensitive -- the faster the suspension moves, the more resistance the shock absorber provides. This enables shocks to adjust to road conditions and to control all of the unwanted motions that can occur in a moving vehicle, including bounce, sway, brake dive and acceleration squat.

Anti-sway bars Anti-sway Bars Anti-sway bars are used along with shock absorbers to give a moving automobile additional stability. An anti-sway bar is a metal rod that spans the entire axle and effectively joins each side of the suspension together. When the suspension at one wheel moves up and down, the anti-sway bar transfers movement to the other wheel. This creates a more level ride and reduces vehicle sway. In particular, it combats the roll of a car on its suspension as it corners. For this reason, almost all cars today are fitted with anti-sway bars as standard equipment, although if they're not, kits make it easy to install the bars at any time.

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2005 本田双们轿车双横臂悬架

2005 本田双们轿车双横臂悬架

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1 车身加速度的幅频特性曲线程序
x=0.1:0.1:20; m2=481; m1=30; u=m2/m1; x0=1.20; w0=2.*pi.*x0; w=2.*pi.*x; b=0.3; a=((1-(w./w0).^2).*(1+9-1./u.*(w./w0).^2)-1).^2+4.*b.*b.*(w./w0).^2.*(9(1./u+1).*(w./w0).^2).^2; d=w./w0; g=9.81; y=w.*9./g.*sqrt((1+4.*b.*b.*d.*d)./a); plot(x,y) grid xlabel('激振频率 f/HZ'); ylabel('|Z2/q|／s-1'); title('车身加速度幅频特性曲线'); gtext('前悬'); legend('f1=1.2,f2=1.3,r=8' ); hold on x=0.1:0.1:20; m2=394 m1=25; u=m2/m1; x0=1.3; w0=2.*pi.*x0; w=2.*pi.*x; b=0.3;
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a=((1-(w./w0).^2).*(1+9-1./u.*(w./w0).^2)-1).^2+4.*b.*b.*(w./w0).^2.*(9(1./u+1).*(w./w0).^2).^2; d=w./w0; g=9.81; y=w.*9./g.*sqrt((1+4.*b.*b.*d.*d)./a); plot(x,y) grid xlabel('激振频率 f/HZ'); ylabel('|Z2/q|／s-1'); title('车身加速度幅频特性曲线'); gtext('后悬');

2 弹簧动挠度幅频特性曲线程序
x=0.1:0.1:10; m2=481; m1=30; u=m2/m1; x0=1.20; w0=2.*pi.*x0; w=2.*pi.*x; b=0.3; a=((1-w./w0).^2).*(1+9-1./u.*(w./w0).^2-1).^2+4.*b.*b.*(w./w0).^2.*(9-(1./u+1). *(w./w0).^2).^2; d=w./w0; y=d.*d.*9./w.*sqrt(1./a); semilogx(x,y) grid xlabel('激振频率 f/HZ'); ylabel('|fd/q|／s'); title('弹簧动挠度的幅频特性曲线'); gtext('前悬'); legend('f1=1.2,f2=1.3,r=8' ); hold on x=0.1:0.1:10;

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m2=394; m1=25; u=m2/m1; x0=1.3; w0=2.*pi.*x0; w=2.*pi.*x; b=0.3; a=((1-w./w0).^2).*(1+9-1./u.*(w./w0).^2-1).^2+4.*b.*b.*(w./w0).^2.*(9-(1./u+1). *(w./w0).^2).^2; d=w./w0; y=d.*d.*9./w.*sqrt(1./a); semilogx(x,y) gtext('后悬');

Suspension System Design of Ben Teng B50 car

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