重型车辆动力换挡过程离合器结合动作时序控制

Timing Control of Clutches Engagement in Power Shift of Heavy-duty Vehicles

建立重型车辆在动力换挡过程中湿式离合器接合过程中滑摩状态的动力学方程,基于减小离合器实际换挡中的换挡冲击和滑摩功,根据车辆换挡前后的车速及将要结合的离合器的扭矩储备系数,通过数字比例溢流阀调整离合器油缸内的压力来控制档位离合器和方向离合器的接合顺序完成动力换挡。整车试验的充/放油油压曲线验证了数字比例溢流阀在PCM的控制下根据车速和离合器的储备系数来决定湿式离合器结合时序的有效性和正确性。

In this paper, dynamics equation of wet clutches in sliding friction state was established. In order to reduce shift shock and friction energy among the shift process, based on the speeds before and after the shift and the torque reserve coefficient of the next engagement clutch, by digital proportional pressure relief valve, we modulate the pressure in clutch cylinder to control the engagement sequence of speed clutches and direction clutches and fulfill the power shift. The curves of recharge and discharge according to test verified that clutches engagement sequence based on speed and clutch reserve coefficient is correct.