全文总字数：8821字

1. 研究目的与意义（文献综述）

the suspension of a cargo truck has anindispensable role, it can mitigate and suppress the vibration and impactcaused by uneven roads, thereby ensuring the comfort of the passengers and theintegrity of the goods being transported. in addition to transmitting thevertical force of the car it also transmits forces and moments in otherdirections, organically connecting the front and rear of the vehicle as awhole, and ensuring a certain kinematic relationship between the wheel and thebody (or frame), so that the car has good driving performance. the developmentof society and the advancement of science and technology, improving thepassenger's riding comfort, driving safety, and economy will become the maingoal of designing automotive suspension in the future. this also shows that thedesign of automotive suspension involves the "automotive theory"knowledge of ride comfort and handling stability in china.

the basic rules of mechanical devices pointout that the good comfort, handling stability, and good load-carrying capacityof trucks cannot be simultaneously satisfied in traditional suspensions usingconstant stiffness and constant damping shock absorbers. therefore, traditionalsuspensions in the design process, it is inevitable to make a compromisebetween ride comfort and handling stability.although the structure oftraditional suspensions has been continuously updated and improved in recent years,the design has been optimized using optimization design methods. the handlingstability has been greatly improved, such as the use of independent arms withwishbone suspension, independent arms with trailing arm, etc., but thetraditional suspension system is still subject to many restrictions, such asthe suspension parameters of the final design, such as spring stiffness,reduced the damping coefficient of the shocker is unadjustable, which resultsin the traditional suspension system can only guarantee that the car achievesthe best performance compromise under a specific road and speed conditions.

at present, more and more air suspensionsystems are used in large commercial vehicles and semi-trailers. the mainadvantages of air suspension systems are good ride, less maintenance, and longlife. at the same time, compared with traditional leaf springs, air springs theprotection performance of passengers and cargo is much better, and the damageto the vehicle and the road is much less. the natural frequency of the airspring is very stable, so its elastic performance is also stable, which meansthat the elastic performance of the air spring is more nearly ideal. with therapid development of china's highway and transportation capacity, theperformance requirements for trucks will gradually increase, which will becloser to the ideal air suspension performance in the future development of theautomotive industry. the application of racks in trucks is bound to be moreextensive. however, since air springs are the most expensive of all kinds ofsuspension elastic components, most trucks currently use leaf springs aselastic components, so in designing trucks when suspending, use the mostsuitable suspension type based on economic factors.

2. 研究的基本内容与方案

the basic content of the design is first todetermine the main parameters of the suspension, including the parameters thataffect ride comfort, parameters that affect steering stability, and parametersthat affect longitudinal stability, and then the size design and calculation ofthe elastic elements, the design of the steering mechanism, and shockabsorption the structure selection and main parameters of the stabilizer, thedesign of the lateral stabilizer bar, and finally the strength check of theentire suspension combined with the relevant knowledge of the ride comfort test

the designed suspension should achieve thefollowing goals:

（1）byrationally designing the elastic and damping characteristics of the suspension,the vehicle is ensured to have good ride comfort, that is, it has a lowvibration frequency, small vibration acceleration, and appropriate vibrationdamping performance, and can avoid compression or stretching in the suspension.a hard impact occurs at the pole of the stroke, while ensuring that the tirehas sufficient grounding capacity.

3. 研究计划与安排

week 1: schemeidea, literature search, completion report

week 2-3: foreignlanguage translation, data collection

weeks 4-6: checkthe main parameters of the suspension, design and calculate the elasticcomponents, design the components of the suspension guide mechanism, and designthe shock absorber structure

4. 参考文献（12篇以上）

[1] 史文库,姚为民. 汽车构造（第六版）[m]. 北京；人民交通出版社,2013.05.

[2] 赫扎特,王国军,朱岩. 汽车构造与原理三维图解：底盘、车身与电器（彩色版）[m]. 北京；机械工业出版社, 2018.09.

[3] 余志生. 汽车理论（第六版）[m]. 北京；机械工业出版社, 2018.11.