Micro slip control method during lock-up meshing of wet clutch

Abstract

The invention discloses a micro slip control method during lock-up meshing of a wet clutch, including: firstly, reading current throttle percentage and engine speed; secondly, looking up a micro slip speed diagram to obtain optimal micro slip speed namely MicroSlip Speed; thirdly, calculating the current rotating speed difference between the engine and the input shaft of a gear reducer; fourthly, calculating the current rotating speed N required to be regulated; fifthly, converting the rotating speed difference into corresponding current variation value, namely the current delta I required to be regulated to control relevant solenoid valve of the clutch, through appropriate PID regulation; sixthly, adding the current delta I of solenoid valve required to be regulated the clutch with the current existing effective current and calculating optimal control current of the solenoid valve during micro slip lock-up meshing of the clutch. The invention can effectively reduce shift impact, reduce oil consumption in frequent shift process and can obviously improve operation reliability of the clutch and prolong the service life of the clutch.

Description

technical field [0001] The invention relates to a control method, in particular to a micro-slip friction control method applied to a wet clutch of an automobile engine and a transmission when locking and engaging. Background technique [0002] The so-called wet clutch refers to the friction contact surface of the clutch friction plate during the sliding friction process, which is the friction of the liquid and semi-liquid interface. Compared with the traditional dry clutch, it has a qualitative change, that is, when sliding, the friction surface There is no direct contact, and the two friction surfaces are separated by a thin layer of oil film with a thickness of about 0.1mm. Wear and stable friction coefficient, and the rupture of the oil film during the friction process will increase the wear sharply. Therefore, compared with the dry clutch, the control of the wet clutch has stricter technical requirements and is more complicated and difficult. [0003] In the traditional...

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Problems solved by technology

Moreover, due to the uncertainty of the dynamic variable friction coefficient in the formula, it is difficult to ensure that the clutch is fully engaged. If unnecessary slip occurs during driving, it will reduce the life and reliability of the wet clutch, which will negatively affect the advantages of the wet clutch. effect, and this method has a large impact on shifting gears, which reduces the driving comfort of the vehicle

[0012] There are also a few foreign literatures that propose to solve the problem of insufficient meshing that may occur through the control method of additional force (Surplus Pressure), that is, to add a certain amount of force on the basis of the theoretical results of the above formula, but under this control, the oil pump in the hydraulic system is for Additional work is required to generate additional force, which will cause greater energy loss, thereby increasing fuel consumption and reducing the economy of the vehicle

Moreover, the additional force is easy to completely discharge the oil film that is conducive to friction from the friction pair, and then a large friction is likely to occur at the moment when the clutch is released from sliding friction, which affects the service life of the wet clutch

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