Patent ID: 7043347

Claim:
A control device for a hydraulic clutch which is provided in a power train of a vehicle to transmit a drive torque, comprising: an oil pressure supply unit which supplies oil pressure to engage the clutch; a sensor which detects a temperature of the hydraulic fluid supplied to the clutch; and a programmable controller programmed to: count an elapsed time following a release of the clutch; and cause the oil pressure supply unit, when the clutch is engaged from a state of release, to precharge the interior of the clutch in accordance with the counted time to fill the interior of the clutch with hydraulic fluid prior to engaging the clutch; determine a precharge pressure based on the temperature of the hydraulic fluid such that the precharge pressure becomes higher as the temperature of the hydraulic fluid decreases; determine a tentative precharge period based on the precharge pressure and the temperature of the hydraulic fluid; calculate a voidage in the interior of the clutch based on the elapsed time and the temperature of the hydraulic fluid; determine a precharge period based on the product of the tentative precharge period and the voidage; and cause the oil pressure supply unit to precharge the interior of the clutch with the precharge pressure for the precharge period.