汽车动力系离合器接合抖振和粘一滑的分析和仿真

Analysis and Simulation of Clutch Engagement Judder and Stick-slip In Automotive Powertrain System

研究分析了离合器接合的抖振和粘一滑以及用数字来检验这些现象的影响系数。为具有汽车变速箱装置的动力系带打滑离合的4自由度(4DOF)的扭振系统开发了一个模型。进行稳态分析表明该离合器的抖振与摩擦系数和斜率有关,并用数字仿真加以证实。开发了模拟粘一滑的一种算法,并用于数字仿真,它表明了由于离合器压力波动,离开接合的抖振和外载荷变动将增加了粘一滑的可能性。由2档换到3档的数字仿真证明,根据离合器接合时作用压力波动,离开接合抖振和外载荷波动发生粘一滑可能增大,而随作用压力倾斜到啮合点发生粘一滑可能性明显减少。

Clutch engagement judder and stick-slip are in vestigated analytically and numerically to examine the influencing factors on these phenomena. Models are developed for a four degree-of-freedom（4DOF）torsional system with slipping clutch and for a powertrain with automatic transmission system. Stability analysis is performed to demonstrate that clutch judder is dependent on the slope of the friction coefficient and the analysis is verified with numerical simulations. An algorithm for modelling stick-slip is developed and is used in numerical simulations which show that the likelihood of stick-slip is increased by clutch pressure fluctuations,judder approaching engagement,and external torque fluctuations. Numerical simulations for second to third gear up shifts demonstrate that the likelihood of stick-slip to occur from clutch engagement is increased by clutch applied presssure fluctuations,judder approaching engagement, and external torque fluctuations and that the likelihood of stick-slip occurring is decreased dramatically by applied pressure ramps proximus to the engagement point.