重型AT换挡控制油压变化及稳定性的研究

Study on Change and Stability of Pressure in Shift Control System of Heavy-duty AT

为了改善和保证重型液力自动变速器的换挡品质,在分析重型液力自动变速器换挡液压控制系统工作原理的基础上,建立换挡回路油压控制数学模型,基于AMESim搭建仿真模型,并从占空比、换挡阀弹簧预紧力和阀口开口量等因素对换挡时离合器油压变化及稳定性展开研究。仿真结果显示:换挡时间约为1.6 s,在t=1~1.6 s期间,这些因素对离合器油压影响较大,而后离合器的油压仅受主油压调节而发生变化,t=3.2 s达到稳定压力,满足实际工作要求;同时仿真结果与理论分析相一致,验证了模型的正确性和有效性,为液力自动变速器换挡控制和装配提供一定的参考。

In order to improve and guarantee the shift quality of heavy-duty automatic transmission,based on the analysis of system operation principles of heavy-duty automatic transmission shift hydraulic control system,the mathematical model of the hydraulic control system was established firstly,and then the simulation model was set up based on AMESim,and the change and stability of clutch hydraulic pressure were studied from those important factors including duty cycle,shift valve spring preload and the opening of shift valve.The simulation results show that the shift time is about 1.6 s,these factors have a great impact on the clutch hydraulic pressure when t=1~1.6 s,then the clutch hydraulic pressure is influenced only by the main oil change;when t=3.2 s,stable pressure is reached which meets the actual job requirements.At the same time the simulation results consistent with the theoretical analysis,verifying the correctness and validity of the model.It provides some reference for gear shift control,assembly and oil temperature control of automatic transmission.