2020上海底盘系统零部件装配及总装技术|上海AMEE汽车底盘展

汽车底盘构造和四大体系详解

[detailedexplanation of automobile chassis structure and foursystems]

悬架

一、作用把车架与车桥弹性连接起来，吸收或缓和车轮在不平路面上受到的冲击和振动，传递各种作用力和力矩。

二、组成一般由弹性元件、导向装置和减振器三部分组成。

三、类型悬架可分为独立悬架和非独立悬架两类。

[1、 the function is to connect theframe and the axle elastically, absorb or mitigate the impact andvibration of the wheel on the uneven road surface, and transfervarious forces and moments.

2、 the composition is generallycomposed of three parts: elastic element, guide device and shockabsorber.

3、 type suspension can be dividedinto independent suspension and non independent suspension.]

1、独立悬架 （如下图a所示）。

独立悬架的特点是：每一侧车轮单独通过弹簧悬挂在车架下面，汽车行使中，当一侧车轮跳动时，不会影响另一侧车轮的工作。独立悬架中多采用螺旋弹簧和扭杆弹簧作为弹性元件，并配用导向装置和减振器。独立悬架在轿车上广泛应用。

2、非独立悬架 （如下图b所示）。

非独立悬架的特点是两侧的车轮分别安装在同一整体式车轿上，车轿通过弹性元件与车架相连。这种悬架在汽车行驶中，当一侧车轮跳动时，另一侧车轮也将随之跳动。非独立悬架中广泛采用钢板弹簧作为弹性元件，这种悬架在中、重型汽车上普遍采用。

四、弹性元件

悬架采用的弹性元件有钢板弹簧、螺旋弹簧、扭杆弹簧、空气弹簧、油气弹簧、橡胶弹簧等。

a、钢板弹簧

钢板弹簧又叫叶片弹簧，它是由若干不等长的合金弹簧片叠加在一起组合成一根近似等强度的梁。钢板弹簧的第一片（zui长的一片）称为主片，其两端弯成卷耳，内装青铜或塑料或橡胶。粉沫冶金、制成的衬套，用弹簧销与固定在车架上的支架、或吊耳作铰链连接。钢板弹簧的中间用u形螺栓与车桥固定。

钢板弹簧在载荷作用下变形，各片之间因相对滑动而产生摩擦，可促使车架的振动衰减。各片间的干摩擦，车轮将所受冲击力传递给车架，且增大了各片的摩损。所以在装合时，各片间涂上较稠的润滑剂（石墨润滑脂），并应定期保养。

b、螺旋弹簧

螺旋弹簧是用弹簧钢棒卷制而成，它们有刚度不变的圆柱形螺旋弹簧和刚度可变的圆锥形螺旋弹簧。

螺旋弹簧大多应用在独立悬架上，尤以前轮独立悬架采用广泛。有些轿车后轮非独立悬架也有采用螺旋弹簧作弹性元件的。由于螺旋弹簧只承受垂直载荷，它用做弹性元件的悬架要加设导向机构和减振器。它与钢板弹簧相比具有不需润滑，防污性强，占用纵向空间小，弹簧本身质量小的特点，因而现代轿车上广泛采用。

c、扭杆弹簧

扭杆弹簧总成用铬钒合金弹簧钢制成，它的表面经过加工很光滑。通常为保护扭杆表面，在其上涂有环氧树脂，并包一层玻璃纤维，再涂一层环氧树脂，zui后涂上沥青和防锈油漆，以防摩蚀和损坏表面，从而提高扭杆弹簧的使用寿命。

d、气体弹簧

气体弹簧主要有空气弹簧和油气弹簧两种。

气体弹簧是以空气做弹性介质，即在一个密闭的容器内装入压缩空气（气压为0.5~1mpa），利用气体的可压缩性实现弹簧的作用。这种弹性元件叫空气弹簧，它分为囊式和膜式空气弹簧。空气弹簧在轿车上有采用尤其在主动悬架中被采用。这种弹簧随着载荷的增加，容器内压缩空气压力升高，使其弹簧刚度也随之增加，载荷减少，弹簧压力也随空气压力减少而下降，因而这种弹簧有其理想的弹性特性。

油气弹簧以气体（氮-惰性气体）作为弹性介质，用油液作为传力介质。

弹簧

suspension

1. independent suspension (as shown in figure a below).

the characteristics of independent suspension are: each side ofthe wheel is suspended under the frame by spring separately. whenone side of the wheel is running out, the operation of the otherside of the wheel will not be affected. in independent suspension,coil spring and torsion bar spring are used as elastic elements,and guide device and shock absorber are used. independentsuspension is widely used in cars.

2. independent suspension (as shown in figure b below).

the feature of non independent suspension is that the wheels onboth sides are respectively installed on the same integral car, andthe car is connected with the frame through elastic elements. whenone side of the wheel of the suspension is bouncing, the other sideof the wheel will also be bouncing. leaf spring is widely used aselastic element in non independent suspension, which is widely usedin medium and heavy vehicles.

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4、 elastic element

the elastic elements used in suspension include leaf spring,spiral spring, torsion bar spring, air spring, oil air spring,rubber spring, etc.

a. leaf spring

leaf spring is also called leaf spring. it is composed of anumber of different length alloy spring sheets which are superposedtogether to form a beam of approximately equal strength. the firstpiece (the longest piece) of leaf spring is called the main piece,and its two ends are bent into rolling ears with bronze or plasticor rubber inside. the bushing made of powder metallurgy is hingedwith a spring pin and a bracket or lifting lug fixed on the frame.the middle of leaf spring is fixed with u-bolt and axle.

the leaf spring deforms under the action of load, and there isfriction between the plates due to relative sliding, which canpromote the vibration attenuation of the frame. the dry frictionbetween the plates will transfer the impact force to the frame, andincrease the friction loss of the plates. therefore, whenassembling, apply a thick lubricant (graphite grease) between eachpiece, and maintain it regularly.

b. coil spring

the coil spring is made of spring steel bar. they havecylindrical coil spring with constant rigidity and conical coilspring with variable rigidity.

coil spring is mostly used in independent suspension, especiallyin front independent suspension. some car rear wheel independentsuspension also use coil spring as elastic element. since the coilspring only bears vertical load, the suspension used as elasticelement should be e with guide mechanism and shock absorber.compared with leaf spring, it has the characteristics of nolubrication, strong antifouling, small longitudinal spaceoccupation and small spring , so it is widely used in moderncars.

c. torsion bar spring

the torsion bar spring assembly is made of chrome vanadium alloyspring steel, and its surface is very smooth after processing.generally, in order to protect the surface of torsion bar, epoxyresin is coated on it, and a layer of glass fiber is coated, thenepoxy resin is coated, and finally asphalt and antirust paint arecoated to prevent friction and damage to the surface, so as toimprove the service life of torsion bar spring.

d. gas spring

there are two kinds of gas spring: air spring and oil gasspring.

the gas spring uses air as the elastic medium, that is to say,compressed air (air pressure is 0.5 ~ 1mpa) is put into a closedcontainer, and the function of the spring is realized by thecompressibility of the gas. this kind of elastic element is calledair spring. it is divided into bag type and membrane type airspring. air spring is used in car, especially in active suspension.with the increase of load, the pressure of compressed air in thecontainer increases, so the spring stiffness increases, the loaddecreases, and the spring pressure decreases with the decrease ofair pressure, so the spring has ideal elasticcharacteristics.

oil gas spring takes gas (nitrogen inert gas) as elastic mediumand oil as force transmitting medium.

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