重型拖拉机动力换挡变速器电液换挡品质研究  

Electro-hydraulic Shift Quality of Power Shift Transmission of Heavy Duty Tractor

作　　者：鲁力群[1] 周雅倩 李辉 王毅 尹永芳[1] 赵静[2] LU Liqun;ZHOU Yaqian;LI Hui;WANG Yi;YIN Yongfang;ZHAO Jing(School of Transportation and Vehicle Engineering,Shandong University of Technology,Zibo 255000,China;School of Agricultural Engineering and Food Science,Shandong University of Technology,Zibo 255049,China)

机构地区：[1]山东理工大学交通与车辆工程学院,淄博255000 [2]山东理工大学农业工程与食品科学学院,淄博255000

出　　处：《农业机械学报》2020年第S01期550-556,602,共8页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家重点研发计划项目(2016YFD070110102)。

摘　　要：为避免动力换挡拖拉机换挡时的动力中断,减少换挡冲击,以某款自主研发的拖拉机全动力换挡变速器为对象,对重型拖拉机动力换挡变速器(Power shift transmission,PST)换挡品质进行研究。换挡重叠时间和最佳接合压力对于提高换挡品质和实现自动换挡有重要意义。以换挡重叠时间和接合压力为切入点,研究不同的压力控制策略对换挡品质的影响。结果表明,换挡重叠时间为0.3 s时,换挡液压冲击最小、滑摩功最少且扭矩损失最少,具有最佳的换挡品质;接合压力在0.40~0.63 MPa(滑差455.2~560.0 r/min)范围内的输出扭矩相同,滑摩功和换挡液压冲击在换挡接合压力为0.40 MPa时有最小值。本研究为进一步实现换挡离合器压力跟踪和精确控制奠定了基础。In order to avoid the interruption of power and reduce the impact of shift in a power shift tractor,the shift quality of a heavy-duty tractor power shift transmission was studied with a tractor full power shift transmission developed independently.The characteristics of torque transfer in the dynamic coupling process of the shifting clutch were analyzed.The key to the steady control of the shifting clutch was the accurate control of the clutch engagement pressure.The influence of different pressure control strategies on gear shifting quality was studied based on the overlap time of gear shifting and engagement pressure.Taking shift hydraulic impact,sliding friction and output torque as the optimization objectives,the influence of overlapping time,engagement pressure and sliding difference of the master and slave moving plate of the shift clutch on shift quality was studied.The higher the engagement pressure was,the smaller the sliding difference of the shift clutch was.If the overlap time of gear shift was too short,it would result in the decrease or interruption of tractor power.If the shift overlap time was too long,two shift clutches would be engaged for a long time at the same time and“double locking”phenomenon occurred.When the clutch was separated,there was a mutating dynamic load on the output shaft.Therefore,the shift overlap time should be controlled reasonably to achieve the best shift quality.The shift control strategy of different shift overlap time was studied.The shift quality was analyzed synthetically by combining shift hydraulic impact and sliding friction,and the optimal shift point was determined under certain conditions.The simulation results showed that when the shift overlap time was 0.3 s,the shift had the lowest hydraulic impact,the least sliding friction power and the least torque loss.Besides,the shift quality was the best.The output torque of the joint pressure was the same within the range of 0.40~0.63 MPa(the slip was 455.2~560.0 r/min).When the joint pressure was 0.40 MPa,the val

关 键 词：拖拉机 动力换挡变速器 换挡品质 电液控制 接合压力 液压冲击 控制策略 

分 类 号：S219.033[农业科学—农业机械化工程]