A main oil circuit pressure control method for preventing clutch slippage in rapid oil filling stage

Abstract

The invention discloses a main oil circuit pressure control method for preventing clutch slipping during the rapid oil filling stage. By detecting the transmission state, it is judged whether the transmission is about to perform a shift operation. If the shift operation is not performed, the command pressure of the main oil circuit remains unchanged. ; If the shift operation is about to be performed, according to the current main oil circuit pressure, the command pressure of the main oil circuit will be increased by △P for the time △T1 before the shift and maintained for the time △T2, and △P, △T1 and △T2 will be The current main oil circuit pressure increases and decreases with the current main oil circuit pressure decrease; after △T2 ends, the main oil circuit compensation pressure △P is cancelled, and the main oil circuit command pressure returns to the initial value. After the command pressure of the main oil circuit rises △P, in the stage of rapid oil filling for shifting, the quick oil filling control pressure of the shift solenoid valve is compensated, and the actual pressure of the main oil circuit can ensure that the lock-up clutch remains locked, which can prevent clutch slippage and runaway Phenomenon, improve shift quality and transmission service life.

Description

technical field [0001] The invention belongs to the technical field of automatic transmissions, and in particular relates to a main oil circuit pressure control method for preventing clutch slipping during a rapid oil filling stage. Background technique [0002] Among the main functions of the transmission, shift control is a very important aspect and also its core. According to the driving or static state of the vehicle when shifting, the shifting is divided into dynamic shifting and static shifting. The dynamic shifting process mainly includes the oil filling phase, torque phase, speed phase and locking phase. The oil filling phase is the first stage of the shifting process, and it includes the fast oil filling stage and the clutch reaching the joint point stage. The fast oil filling stage has an important influence on the shifting quality. [0003] In the rapid oil filling stage of the gear shifting process, affected by the characteristics of the solenoid valve, the rapi...

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Problems solved by technology

[0003] In the rapid oil filling stage of the gear shifting process, affected by the characteristics of the solenoid valve, the rapid increase of the solenoid valve current will cause the leakage to increase instantaneously at this stage, and the increase in leakage will cause the pressure of the main oil circuit to decrease instantaneously, resulting in a lock-up clutch. Slippage will cause the motor or engine to run away. Severe runaway will cause ablation of the friction plate of the clutch, which will affect the performance of the clutch and shorten its service life.

[0004] At present, domestic and foreign automatic transmission control methods do not involve the main oil circuit pressure control method to prevent the clutch from slipping during the rapid oil filling stage during the shifting process, so it is impossible to overcome the instantaneous main oil circuit pressure caused by the increased leakage of the solenoid valve. The problem of lowering will lead to clutch slipping and speeding, and even damage the clutch in severe cases

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