Method for controlling locking clutch of hydraulic torque converter under situation that accelerator is emergently released

Abstract

The invention relates to a method for controlling a locking clutch of a hydraulic torque converter under the situation that an accelerator is emergently released. When a car runs by normally stepping on the accelerator, the turbine rotation speed of the hydraulic torque converter is smaller than the pump impeller rotation speed, and it is detected that a driver suddenly releases the accelerator at the time point T3 in the locking clutch oil pressure increasing stage after oil pressure of the locking clutch is built, all situations are set up, and all stages of control operates are completed in sequence, specifically, in the first stage, the control oil pressure value of the locking clutch drops from the oil pressure value A of the time point T3 to the oil pressure B of the half engagement point of the locking clutch, in the process, the pump impeller rotation speed is decreased slowly under the action of the suddenly decreased engine torque, dropping of the control oil pressure of the locking clutch can buffer the effect of clutch locking acceleration caused by sudden release of the accelerator, and impact caused by rapid engagement of the clutch is avoided; the second stage and the third stage have the effect of completely limiting the pump impeller rotation speed in a timely response mode so that the pump impeller rotation speed can be prevented from being excessively adjusted or duration of the locking process can be prevented from being prolonged.

Description

technical field [0001] The invention relates to a control method for a lock-up clutch of a hydraulic torque converter. Background technique [0002] The torque converter lock-up clutch control can optimize the lock-up area of ​​the torque converter, reduce the loss of hydraulic transmission as much as possible, and improve the fuel economy of the vehicle. At present, the relevant mature control technologies include the torque converter lock-up strategy control to precisely control the unlocking timing of the torque converter, and the torque converter slip-friction control strategy to control the lock-up process of the torque converter lock-up clutch. Precise control. Based on these mature technologies, the hydraulic torque converter can complete the lock-up of the clutch at the right time with the smoothest control process. However, there is no special control scheme for some special working conditions with a low probability of occurrence, such as sudden gas acceleration o...

AI Technical Summary

Problems solved by technology

When the lock-up clutch of the hydraulic torque converter is in the process of lock-up control, the driver suddenly sends off the throttle ( figure 1 T3 time point), the engine torque will drop suddenly, but the hydraulic torque converter lock-up clutch oil pressure will continue to be controlled accordi

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