Patent ID: 8701397

Claim:
A hydraulic oil supply device installed in a construction machine to supply hydraulic oil, the hydraulic oil supply device comprising: a work equipment pump that supplies the hydraulic oil to a hydraulic actuator that drives the work equipment; a fan pump that supplies the hydraulic oil to one of the hydraulic actuator and a hydraulic motor that drives a cooling fan; a control valve that controls a supply of the hydraulic oil from the work equipment pump to the hydraulic actuator; a circuit switching valve that selectively connects a discharge portion of the fan pump to the hydraulic actuator and the hydraulic motor; a control body for operating a movement of the control valve, the control body being configured to generate an operation signal output based upon being operated by a user to control the work equipment; a movement position detector for detecting a movement position of the work equipment, the movement position detector being configured to output a detection signal based upon detecting the movement position of the work equipment; and a controller configured to receive the operation signal output from the control body and the detection signal from the movement position detector and configured to switch the circuit switching valve based on the operation signal output and the detection signal, wherein based on receiving the operation signal output and the detection signal, the controller switches the circuit switching valve, and the hydraulic actuator receives hydraulic oil discharged from the fan pump in addition to receiving hydraulic oil discharged from the work equipment pump.