Post-processing Strategy of Hub-type Shift Mechanism 3DHT After Hitting Teeth

The structure characteristics, power transmission principle, working principle of clutch actuator and shift actuator of 3DHT are analyzed, and the post-processing control strategy after the impact of teeth is proposed and tested. The main source of power for the transmission is the P3 motor, which is directly connected to the main reduction gear of the differential. When the engine power drives the vehicle, it is necessary to hook the transmission into forward gear and engage the clutch CO. The transmission includes three forward gears, which can be reversed when the motor P3 is reversed. The shift motor drives the reduction gear to rotate, and the gear rotation drives the shift hub to rotate, the slide on the shift hub will push the shift fork to move, the fork will control the direction of movement, and the shift fork will push the synchronizer to engage to achieve the shift. Because of the structure of the shift hub, there are multiple neutral positions. It is easy to hitting teeth when the synchronizer is in gear, which causes no gear to be in gear. In order to solve the problem of unhanging gear caused by the hitting teeth, a post-processing control strategy is proposed. The overall strategy is: When the hitting teeth occur, the gear is now returned to the nearest original neutral, and then give the clutch a larger engagement torque, when the clutch engages, let P1 motor torque mode, while P1 produce a small torque, when the synchronizer produces a slip value, prove that the synchronizer position has changed, then start to shift again, which reduces the probability of the hitting teeth. According to the configuration of the vehicle, a real vehicle verification platform is built to test the actual working conditions of the impact gear, and the running conditions are tested by using the actual parameters. By monitoring the internal signal information, the proposed post-processing control strategy after the hitting teeth can be reflected, and the relative position of the synchronizer can be effectively changed, so as to avoid the hitting teeth working condition again.