Patent ID: 6481388
Filing Date: 2002-11-19
Classification: F01P

Abstract:
A cooling fan drive control device comprising a hydraulic pump driven by a drive source, a cooling fan which cools cooling water of the drive source and also cools pressure oil of equipment operated by the drive source, and a hydraulic motor which is operated by pressure oil discharged from the hydraulic pump and causes the cooling fan to rotate,wherein the cooling fan drive control device further comprises: a cooling water temperature sensing means which senses a temperature of the cooling water; a pressure oil temperature sensing means which senses a temperature of the pressure oil; a target fan rotation speed setting means which sets a target fan rotation speed to a first target fan rotation speed corresponding to the cooling water temperature sensed by the cooling water temperature sensing means, or to a second target fan rotation speed corresponding to the pressure oil temperature sensed by the pressure oil temperature sensing means, whichever is the larger; and a capacity control means which controls a capacity of the hydraulic pump or the hydraulic motor according to a difference between a fan rotation speed of the cooling fan and the target fan rotation speed set by the target fan rotation speed setting means.