汽车制动器疲劳试验台架优化设计

Optimization Design of Fatigue Test Bench for Bus Brake

对目前常用的汽车制动器疲劳试验台架的优缺点进行研究分析,进行试验台架的优化设计。用扭矩传感器替代液压扭臂扭矩测量机构,解决了液压系统易漏油问题;在工装夹具中加入心轴,改善工装夹具的刚度性能,提高了试验的稳定性;在试验台上增加了恒温箱系统,可以对非常温工况进行疲劳测试。运用正交试验对工装夹具在满足强度和刚度的条件下进行轻量化设计,对轻量化设计后工装夹具进行150℃工况下热应力分析和疲劳分析。根据金属材料热膨胀的特性提出了一种制动器试验台架的控制方法,可避免工件在发生热膨胀后发生干涉的问题。结果表明:加入芯轴后工装夹具刚度提高15%;在应力循环400000次下,工装的疲劳损伤值为0.00379,工装夹具使用寿命为10年。结果证明了疲劳台架设计的可行性。

Analysis of the advantages and disadvantages of common bus brake fatigue test bench was conducted to optimize the design. The problem of oil leakage in the hydraulic system could be solved by replacing the torque measurement mechanism of hydraulic driving with a torque sensor. The stiffness performarwe of fixtures and the stability of test could be improved by joining a mandrel between two fixtures. Besides, in order to do experiments at different temperatures, an incubator system was set on the test bench. Lightweight design for this fixture was studied via orthogonal test under a better strength and stiffness condition. Then, the thermal stress and fatigue analysis of this fixture was numerically implemented in 150~C condhior~ Based on the thermal expansion characteristics of metal materials, a control method of brake test bench was proposed to avoid inteoCerence between brake and brake drum The study result showed that the stiffness of the fixture was improved by 15% after adding a mandrel; fatigue damage of the fixture was 0.00379 after 400000 stress cycles, the life reached up to 10 years. The result verified the feasibility of the structure desigr.