Patent ID: 8127541

Claim:
A working fluid cooling control system for a construction machine having variable displacement type hydraulic pump, a plurality of members to be operated by said hydraulic pump, a heat exchanger for cooling a working fluid as an operating medium discharged from said hydraulic pump, a plurality of control valves for controlling respective flows of the working fluid delivered from said hydraulic pump to control the operation of the corresponding members to be operated, and a plurality of operation means provided for said plural control valves, respectively, the capacity of said hydraulic pump being increased depending on an increase in the operative amount of said plural operation means while the capacity of said hydraulic pump being decreased to a preset amount of a minimum capacity when said plural members to be operated enter an unoperated state, wherein the working fluid cooling control system comprises: first detection means for detecting an operation pattern corresponding to a rise in temperature of said working fluid from among operation patterns associated with said plural members to be operated; and pump flow rate increasing means which increases the capacity of said hydraulic pump so as to increase an average flow rate of the working fluid passing through said heat exchanger when said first detection means detects the operation pattern corresponding to a rise in temperature of said working fluid, said first detection means being configured to detect, as the operation pattern corresponding to a rise in temperature of the working fluid, at least one of two operation patterns, one being a first operation pattern such that an operation speed of one of said plural members to be operated having a higher frequency of heavy loading than at least one of the other members increases, and the other being a second operation pattern such that a particular operation mode is selected by a selector means among operation modes associated with said plural members to be operated, said particular operation mode providing a higher frequency of heavy loading than at least one of the other operation modes.