轻型汽车悬架设计THE DESIGN OF A LIGHT TRUCK`S SUSPENSION
2009 年6 月
本文主要研究轻型货车的前后悬架设计分析方法，以及悬架运动与前轮定位参数的变化关系。
首先根据设计给定的四个参数对整车进行总体设计，包括整车的尺寸参数、质量参数和性能参数，在选择这些参数的时候可以通过国家标准以及相关的经验参数得到，在选择之后进行了相关的验证，保证各参数能达到各项性能的基本要求。在总体设计完成之后，对前后悬架进行方案的选择，本设计前悬架采用麦弗逊独立悬架，后悬架采用纵置钢板弹簧。然后对悬架的性能参数进行选择，包括前后悬架的偏频、相对阻尼系数、非簧载质量以及影响操稳性的侧倾中心高度和侧倾刚度，还有影响纵向稳定性的纵倾中心高度等。在选择完基本参数后，对悬架的弹性元件（前悬架为螺旋弹簧。后悬架为钢板弹簧）进行设计计算，包括刚度和强度等的校核，使设计的弹簧能满足设计的偏频要求。之后设计前独立悬架的导向机构，设计包括侧倾中心、纵倾中心以及下控制臂的位置等。为前、后悬架匹配减振器，计算减振器的尺寸，并且验算减振器是否满足强度要求。由于麦弗逊悬架的侧倾刚度较小，为了满足汽车不足转向性能要求，设计时，为前悬架匹配了一个横向稳定杆，提高它的侧倾刚度，满足不足转向性能要求。
由于悬架结构的运动学特性关系到汽车操纵稳定性、转向轻便性、行驶舒适性、轮胎寿命以及汽车布置设计中的运动干涉等诸多方面，是汽车设计过程中十分重要的问题，欲设计合乎需要的悬架结构,必须准确分析悬架结构的运动特性。所以为了研究悬架结构的运动学特性，本文采用了空间解析几何的方法，探讨分析了麦弗逊式悬
架的运动学特性，由于该方法能够直接使用整车布置设计坐标系,无需进行坐标转换
且直观方便,易于理解,所以具有实际应用的意义
关键词：麦弗逊悬架动态特性
Abstract
This article is mainly about to study the method of designing a light truck ' fsr ont and back suspension, also the article analyze the relation between suspension movement and front wheel alignment parameters.
First, it designs the scheme of whole car based on the four parameters
which was already been given, this including the whole car ' s size parameters, weight parameters, and property parameters. we may choose those parameters refer to national standards or some relative experience parameters. we may also do some work to prove the chosen was correct after those parameters being chosen, as to make every parameters meet the basic demand of every property. when the whole car schemes were already designed, it then comes to choose the scheme of the front and back suspensions, and in this design, we use McPherson type front suspension, Back suspension 'sst eel spings.and then, we choose the suspension ' s property paremeters,including front and back suspension ' fsre quency, relative
viscosity,unsprung mass and roll center height, roll angular rigidity which effect the car ' s controllability and stability,besides,we also choose the trim center height which effect the car ' slo ngitudinal control lability. After these basic parameters were chosen, we comes on to calculate the spring of the
suspension,(spiral spring in front suspension, leaf spring in back suspension),and
the calculation including checking both the springs` stiffness and strength, as to make the spring designed to meet the demand of frequency. And next comes to design the control bars of the front independent suspension, it contains to design the roll center height an trim center height and the locations of the main controlbar.Then,we design shock absorbers to match with the front and the back suspension, including calculate the size of the absorbers and also check the absorbers to see if it meets the demand of strength. Since McPherson type front suspension is lack of roll angular ri gidity, in order to meet the property demands of car under steer speciality,Here it also designs a anti-roll bar to improve the front suspension ' s roll angular rigidity.
As suspension ' ksi nematics character relates to a whole car ' s controllability ,steering agility, ride comfort,tyre life and motion interference in the design of the whole car scheme'. th s e kinematics character comes to
be a very important question, to make a good suspension structrue,it needs to analyze the kinematics character of the suspension.And in this article, we uses Spatial analytic geometry to discuss McPherson type front suspension ' s kinematics character. Because the method is able to use the whole car scheme design coordinate system directly, there is no need to transform the coordinate system. It is more convenient and easy to understand,so,it makes more actual
application sense.