Pressure characteristic abnormality processing method for DCT transmission

Abstract

The invention discloses a pressure characteristic abnormity processing method for a DCT (dual clutch transmission), which is characterized in that under certain conditions, according to different working conditions of a clutch, distinguishing diagnosis is performed by combining actual pressure and target pressure, corresponding processing is performed by using information such as vehicle speed, KP pressure and gear, and specifically, in a complete combination state, a limp flushing program can be decided to be executed based on the vehicle speed, pressure difference and KP pressure; in the oil pre-charging state or the preparation working state, the limp flushing program can be decided to be executed based on the actual pressure, the target pressure, the pressure difference and the KP pressure; and trying recovery is carried out by adopting flushing measures, pressure characteristic abnormal faults are output in time after trying is invalid, and the limping mode is controlled to be entered. On the premise of preventing false alarms, the problem that pressure characteristic abnormity is difficult to diagnose is effectively avoided, and by differentially treating the working conditions of the double clutches, the drivability problem caused by the pressure characteristic abnormity can be avoided, and meanwhile power interruption can be avoided.

Description

technical field [0001] The invention relates to the technical field of gearboxes, in particular to a method for handling abnormal pressure characteristics of a DCT gearbox. Background technique [0002] A typical wet DCT (Dual Clutch Automatic Transmission) consists of two coaxial nested or parallel clutches, two coaxial and inner and outer nested input shafts, two parallel output shafts, arranged on the output shaft It consists of multiple synchronizer devices, multiple shift forks, 1 differential, and 1 HCU (hydraulic unit). Among them, solenoid valves with different functions are distributed on the HCU. When the gearbox is working, by controlling the solenoid valves, the corresponding actuators are controlled by hydraulic drive. The main actuators include clutches and synchronizer forks. [0003] As the core component of the DCT transmission, the dual clutch is mainly used to transmit the engine torque to the gearbox, and then to the wheels through the gearbox to drive t...

AI Technical Summary

Problems solved by technology

[0005] 1. The signal of the pressure sensor itself is faulty, and the obtained pressure value is not accurate;

[0006] 2. The aluminum filings and iron filings generated during the operation of the gearbox cause the CPCV valve to be stuck and unable to perform according to the expected pressure

[0010] (1) Regular active flushing cannot completely avoid the abnormal pressure characteristics. After the abnormal pressure characteristics occur, there is no treatment measure, and it can only enter into a limp, resulting in a decrease in drivability;

[0011] (2) The diagnosis does not distinguish between working conditions. When the clutch does not transmit torque and does not transmit torque, the pressure requirements are different, so it has different effects on the drivability of the vehicle;

[0012] (3) Due to the hysteresis of the hydraulic system, under some normal working conditions, the actual pressure is greater than the target pressure within a certain period of time. If a diagnosis is made, it will be falsely reported; if no diagnosis is made, the abnormal pressure characteristics cannot be effectively prevented, resulting in vehicle jitter even turn off

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