Manual gear shifting device of two-gear speed changing box

Abstract

The invention discloses a manual gear shifting device of a two-gear speed changing box. In the process that an electric automobile is switched to a low-speed gear from a high-speed gear, after a synchronizer is moved to a neutral gear from the high-speed gear, a gear shifting controller firstly detects whether the difference value of the rotation speed of the synchronizer and the rotation speed of a low-speed tooth is smaller than the set value h1 or not, if the difference value of the rotation speed of the synchronizer and the rotation speed of the low-speed tooth is larger than the set value h1, it is shown that the rotation speed difference value of a synchronous tooth and the low-speed tooth is too large, gear shifting cannot be conducted, then the gear shifting controller controls a motor to accelerate so that the rotation speed of the low-speed tooth can be increased till the rotation speed difference value of the low-speed tooth and the synchronizer is smaller than h1, then the synchronizer is stirred to the low-speed tooth position, synchronous engagement is achieved, and gear shifting is achieved. By utilization of the method, any switchover from the high-speed gear to the low-speed gear can be achieved for the electric automobile.

Description

technical field [0001] The invention relates to the field of shifting of electric vehicles, and more specifically relates to a manual shifting device for a two-speed gearbox. Background technique [0002] The two-speed gearbox for electric vehicles is attached figure 1 As shown, it includes: a first shaft 1, a second shaft 4 and a differential assembly 9. The motor directly drives a shaft 1 to rotate. The first shaft 1 is connected with the large tooth 3 and the small tooth 2, and the second shaft 4 is slidingly connected with the fast tooth 5 and the slow tooth 6, the fast tooth 5 meshes with the large tooth 3 on the first shaft 1, and the slow tooth 6 and the The small teeth 2 on the first shaft 1 mesh, and the second shaft 4 is also connected with a synchronizer 7 and a fixed tooth 8 . The synchronizer 7 and the fixed teeth 8 rotate at the same speed as the two shafts 4 . The fixed teeth 8 input the power of the two shafts 4 to the differential gear assembly 9 . The ...

AI Technical Summary

Problems solved by technology

[0003] However, because the gearbox of an electric vehicle has fewer gears, and the speed difference between the high-speed gear and the low-speed gear is large, it is impossible to realize high-speed gear shifting, especially the switching from high-speed gear to low-speed gear.

In the process of switching from high-speed gear to low-speed gear, the shift lever first shifts from high-speed gear to neutral gear. After the shift controller receives the signal from the shift lever to switch from high-speed gear to neutral gear, the shift controller cuts off the motor acceleration signal. As a result, the first shaft 1 loses its power source, and the force between the synchronizer 7 and the fast gear 5 disappears. Afterwards, the shift controller controls the shift actuator to pull the synchronizer 7 away from the fast gear 5, and then pulls the synchronizer 7 to the Neutral position, after that, after the shift controller receives the signal from the shift lever from neutral to low gear, the shift controller controls the shift actuator to move the synchronizer 7 close to the slow gear 6. At this time, due to inertia, The synchronizer 7 and the second shaft 4 are still running at a relatively high speed, but the first shaft 1 will decelerate rapidly due to the loss of the power source, resulting in the rapid deceleration of the small tooth 2 and the slow tooth 6 meshing with the small tooth 2, The speed difference between the slow gear 6 and the synchronizer 7 is large, and it is difficult to realize the synchronous meshing between the synchronizer 7 and the slow gear 6, so it is impossible to switch from the high gear to the low gear

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