Method for estimating temperature of 4WD coupling device wet clutches in severe operating condition

Due to the increasing demand for multi-purpose vehicles, there has been a noticeable increase in the sales volume of 4-wheel-drive (4WD) vehicles such as Sports Utility Vehicles (SUV). Most 4WD vehicles are equipped with a coupling device which transfers driving power to the rear drive shaft. In some severe operating condition, wet friction clutches in a coupling device generate enormous heat from friction and cause a sharp temperature increase. Excessive heat can cause thermal damage on the surface material of the clutch. Therefore, a method estimating temperature of the clutch is required to avoid thermal damage. This study suggests a method for estimating temperature of clutch. A full car dynamic model was constructed to simulate the severe driving conditions of a 4WD vehicle and the results of the experimental validation of the temperature estimation model are presented.