Wet clutch friction plate convection heat exchange coefficient mathematical model construction method

Abstract

The invention relates to a wet clutch friction plate convection heat exchange coefficient mathematical model construction method. The method comprises the following steps of firstly, establishing a sliding friction work expression for a clutch in a clutch combination process; dividing the clutch combination process into a plurality of infinitesimal equal time periods, obtaining the infinitesimal sliding friction working amount of the clutch in each infinitesimal equal time period according to a clutch sliding friction working model, and measuring the friction plate temperature change amount and the cooling oil temperature change amount in each infinitesimal equal time period respectively; obtaining the infinitesimal energy variation of a friction plate, obtaining the infinitesimal energy variation of the cooling oil according to the infinitesimal sliding friction working amount of the clutch and the infinitesimal energy variation of the friction plate, obtaining a infinitesimal heat exchange coefficient according to the infinitesimal energy variation of the cooling oil, and obtaining a heat exchange coefficient curve during the clutch combination process, and finally obtaining a heat exchange coefficient mathematical model.

Description

technical field [0001] The invention belongs to the field of automobiles, and in particular relates to a method for constructing a mathematical model of a convective heat exchange coefficient of a friction plate of a wet clutch. Background technique [0002] In recent years, with the development of transmission technology, wet dual-clutch automatic transmissions have been widely used in automobiles. Due to the needs of continuous starting, stopping and shifting during the running of the car, the clutch needs to be engaged and disengaged frequently during the working process. In the process of clutch engagement, the friction plate continuously generates heat during the process of continuous friction from relative slip to complete synchronization, resulting in an increase in the temperature of the friction plate, which is likely to cause ablation damage to the friction plate, resulting in early failure of the clutch. In order to improve the thermal load of the clutch and redu...

AI Technical Summary

Problems solved by technology

Due to the complex structure of the clutch friction plate, many oil grooves and irregular shapes, it is impossible to directly use the classic empirical model of heat transfer for calculation

The friction plate and cooling oil heat exchange process involves factors such as the heating state, structure and heat transfer area, cooling flow state, and cooling oil quality of the friction plate at each stage of the clutch engagement process. It is a complex dynamic process related to multiple factors. , there is no classic mathematical expression for reference at this stage, which has become the biggest difficulty in solving the temperature prediction model

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