【作者】 李云龙；

【导师】 刘涛；

【作者基本信息】 哈尔滨工业大学 ， 车辆工程， 2018， 硕士

【摘要】 鼓式制动器诞生近一个世纪以来,以其简单的工作原理、低廉的造价、较大的制动效能,占有了很大的市场,尤其在中大型客车及货车上。鼓式制动器结构形式多种多样,但摩擦片接触不均匀的问题仍然亟待解决。如何在不改变鼓式制动器体积的前提下,提升制动器的使用性能,这具有重要意义。本文从鼓式制动器的支撑销的结构着手,通过改用具有浮动功能的支撑销组件,使制动蹄具有浮动的功能,改变制动蹄的运动趋势,从而达到改善制动器性能的目的。首先,本文从理论上分析了鼓式制动器各主要尺寸对制动器接触的影响,通过使用Matlab仿真分析,证实了制动蹄的浮动对摩擦片的接触有着直接的影响,并得出了不同的浮动方向下、不同的浮动距离与摩擦片接触区域之间的变化规律。接着考虑了在摩擦片产生弹性线性变形的情况下,推导了制动器摩擦片的受力状况及完全接触条件,并计算了摩擦片完全贴合制动鼓时,制动蹄的理论最佳浮动角度。随后,在有限元分析软件ANSYS Workbench中建立了径向浮动的制动器模型,仿真分析其动力学性能,分析结果与实验数据相吻合,表明有限元分析能够准确地描述制动器的制动过程。选取不同的浮动角度进行优化分析,以优化摩擦片的接触为主要优化目标,最终得到在推导的理论最佳浮动角度下,摩擦片与制动鼓贴合得最好,并且制动力矩得到了提升。过大或过小的浮动角度,都会恶化摩擦片的接触状况,使得制动效果不稳定,不能满足使用的要求。最后,对比了两种制动器的制动跑偏程度。在不同的制动鼓偏心方向上,分别对普通制动器和采用了领蹄最佳浮动方向的制动器进行性能仿真验证。结果表明普通制动器在不同的偏心方向上制动性能表现差别较大,浮动式制动器在不同的偏心方向上制动性能表现稳定。综合有限元分析的结果,说明了本文依据制动蹄受力计算得到的理论最佳浮动角度合理,浮动式制动器的接触状况可以得到明显的改善,制动过程的表现也要优于普通的鼓式制动器,同时在对一定程度装配误差存在的时,制动跑偏的情况也得到了改善。更多还原

【Abstract】 Nearly a century after the birth of the drum brakes,it occupies a large market with its simple working principle,low cost,and high braking performance,especially in medium and large passenger cars and trucks.Drum brakes have a variety of structural forms,but the problem of non-uniform friction plate contact remains to be solved.How to improve the performance of the brake without changing the volume of the drum brake is of great significance.This paper starts from the structure of the supporting pin of the drum brake.By changing the support pin assembly with floating function,the brake shoe has a floating function and changes the brake shoe’s movement tendency,so as to achieve the purpose of improving the performance of the brake.First of all,this paper theoretically analyzes the influence of the main dimensions of the drum brake on the contact of the brake.Through the use of Matlab simulation analysis,it is confirmed that the fluctuation of the brake shoe has a direct impact on the friction plate contact,and draws a different float In the direction,the different floating distance and the change law of the contact area between the friction plates.Then,considering the elastic linear deformation of the friction plate,the force conditions and complete contact conditions of the brake friction plate are deduced,and the theoretical optimal floating angle of the brake shoe when the friction plate is completely fitted to the brake drum is calculated..Subsequently,a radial floating brake model was established in the finite element analysis software ANSYS Workbench.The dynamic performance was simulated and analyzed.The analysis results were consistent with the experimental data,indicating that the finite element analysis can accurately describe the brake braking process.Selecting different floating angles for optimization analysis to optimize the contact of the friction plates is the main optimization goal.Ultimately,under the deduced theoretical optimal floating angle,the friction plate is best fitted to the brake drum,and the braking torque is obtained.Promote.If the float angle is too large or too small,the contact condition of the friction plate will deteriorate,making the braking effect unstable and unable to meet the requirements of use.Finally,the degree of brake deviation of the two types of brakes is compared.In the direction of eccentricity of the different brake drums,performance simulations were performed on the normal brake and the brake with the best floating direction of the leading hooves,respectively.The results show that the braking performance of ordinary brakes varies greatly in different eccentric directions,and the braking performance of the floating brakes is stable in different eccentric directions.The results of the integrated finite element analysis show that the theoretical optimal floating angle obtained from the calculation of the brake shoe force in this paper is reasonable,the contact condition of the floating brake can be significantly improved,and the performance of the braking process is also better than that of ordinary drums.The brake is also improved when the assembly error exists for a certain degree.更多还原