关键词: 双离合变速器；低温；换挡；电机电流

Abstract: In view of the phenomenon of large shifting motor current in dual-clutch transmission vehicles at low temperature, this paper analyzes that it occurs when changing the first gear according to the problem condition. According to the use scenario, there are four working conditions when changing the first gear. First, 2－1 shifting in the process of D gear deceleration, and the shifting mechanism has the action of changing the first gear. Second, R gear (R gear+pre-mounted N gear) decelerates to about 4 km/h and then changes D gear (1 gear+pre-mounted R gear), and the shifting mechanism has the action of changing 1 gear. The third is R gear (R gear+pre-mounted N gear) slow down and stop (R gear+pre-mounted 1 gear), and the shifting mechanism has pre-mounted 1 gear action. Fourth, D gear decelerates to about 3 km/h speed (2 gear+pre-hanging N gear), change R gear (R+pre-hanging 1 gear), and the shifting mechanism has pre-hanging 1 gear action. According to the real vehicle verification, the large motor current occurs in the fourth working condition. According to the control logic of the dual-clutch transmission system, this paper limits the engine torque in a suitable range by software calibration, which can effectively reduce the shifting motor current and shift force. Finally, through risk assessment and real vehicle verification, the scheme can meet the requirements of drivability.

Key words: dual-clutch transmission; low temperature; shift gear; motor current