Downshift control method and device for dual clutch transmission

Abstract

The invention provides a downshift control method and device of a dual clutch transmission. The method comprises the steps that when a coaxial power downshift command is received, clutches in a working state are opened; and the actual rotating speed of an engine is regulated to the target rotating speed, and the clutches are closed after it is judged that a target gear shifting fork is put in place. Under the circumstance that the rotating speed of the engine is low, an accelerator is stepped on in the sliding process, and coaxial downshifting is triggered, the whole gear shifting time is thesum of time for disengaging and engaging of the shifting fork once, compared with an existing technical scheme, the time of one time of shifting fork engaging and the time of one time of torque interacting are omitted, and therefore, the power response time of coaxial downshifting is shortened.

Description

technical field [0001] The invention relates to the field of dual-clutch transmissions, more specifically, to a downshifting method and device for dual-clutch transmissions. Background technique [0002] The clutch is located between the engine and the gearbox, and is an important part that connects the engine and the gearbox for power transmission. The closing and disconnection of the clutch is the transmission and termination of the power of the engine. The technical key of the dual-clutch transmission lies in the dual-clutch, that is, there are two clutches, one of which is responsible for odd gears (1, 3, 5 gears), and the other clutch is responsible for even-numbered gears (2, 4, 6 gears). The two sets of clutches will be cut off and closed in turn during work. When one clutch is working, the next clutch will enter the standby state. Once the working clutch is disconnected, the standby clutch will start working immediately. [0003] Currently, most DCTs are set up wit...

AI Technical Summary

Problems solved by technology

[0003] Currently, most DCTs are set up with the clutch on standby in a high gear, so that when the driver steps on the accelerator to activate a coaxial power downshift, two power interactions and at least three fork disengagements are required with the help of the other shaft. hanging, resulting in slow dynamic response

like figure 1 Take the dual-clutch transmission with the structure shown as an example. When downshifting from 4th gear to 2nd gear is required, you must first downshift from 4th gear to 3rd gear. Gear, that is, after the 2nd gear shift fork B is removed, the 3rd gear shift fork A is taken off, the entire downshift process takes a long time to shift gears, and the power response is slow

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