Pre-charge control method of wet clutch in hybrid transmission

Abstract

The invention provides a method for controlling pre-filling oil of a wet clutch in a hybrid transmission. When the clutch is opened, the clutch oil circuit remains full of oil. The solenoid valve current of the controller controls the clutch to rise rapidly to I1, and then the vehicle controller controls the solenoid valve current of the clutch to rise to I2 according to the gradient △V, and the pressure of the high-pressure oil in the piston begins to rise. When the thrust generated by the high-pressure oil exceeds the return spring After the resistance, the piston of the clutch starts to move. When the moving distance of the clutch piston reaches the preset value A, the vehicle controller controls the solenoid valve current of the clutch to drop rapidly from I2 to I3, so that the clutch pressure drops to the kisspoint point, and Maintain the clutch piston position unchanged. The method of the invention is simple and feasible. By optimizing the current increase curve of the clutch electromagnetic valve, the peak demand for the flow rate during the clutch pre-filling process is reduced, and the system efficiency and reliability are improved.

Description

technical field [0001] The invention relates to a method for controlling pre-filling oil of a wet clutch in a hybrid transmission. Background technique [0002] The normal operation of the gearbox usually requires the hydraulic system to provide high-pressure oil and low-pressure oil at the same time. The high-pressure oil is mainly used for the control of the clutch, and the low-pressure oil is mainly used for the lubrication of the bearings and gears, and the cooling of the clutch. The oil pump of the transmission needs to meet the flow requirements of high-pressure oil and low-pressure oil at the same time. The high-pressure control flow and low-pressure cooling flow are only in great demand under certain working conditions, and the demand for other working conditions is small, while the demand for low-pressure lubrication flow continues to exist. And the range of change is small. The maximum required flow of high-pressure oil occurs during the short process of clutch pr...

AI Technical Summary

Problems solved by technology

However, it takes a certain amount of time to increase the speed of the electric pump. If the adjustment of the speed of the electric pump is completed first and then the pre-filling of the clutch is performed, the shift time will be significantly increased. If the flow rate is insufficient, the pressure of the main main oil circuit will drop, which in turn will cause the pressure of other lock-up clutches to drop, resulting in slipping, and it is difficult to balance economy and reliability.

[0006] In the prior art, in order to meet the demand for flow during the clutch pre-filling process and reduce the pressure drop of the main main oil circuit, the gearbox usually has three solutions. The first is to always maintain a large flow. This method The disadvantage of this method is that it will reduce the efficiency of the system. The second is that when shifting gears, first increase the speed of the electric pump and then shift gears. The disadvantage of this method is that it will increase the shifting time and reduce the response to driving intentions. The third The first is to increase the speed of the oil pump for a period of time in advance. The disadvantage of this method is that it will also reduce the efficiency of the system. In addition, after the speed of the oil pump is significantly increased, it will cause noise problems.