Patent ID: 8875820

Claim:
A hybrid construction machine comprising: an engine as a power source; an electric storage device that is set to an appropriate temperature lower than an appropriate temperature of the engine; equipment that needs cooling, including a motor and a controller therefor, and set to an appropriate temperature lower than the appropriate temperature of the electric storage device; an electric storage device temperature adjustment circuit for maintaining the electric storage device at the appropriate temperature; an engine cooling circuit cooling the engine with a first coolant; a warm-up switching valve that is provided in the engine cooling circuit and capable of switching between an electric storage device warm-up position in which the first coolant after cooling the engine is introduced into the electric storage device temperature adjustment circuit and an electric storage device non-warm-up position in which the introduction of the first coolant into the electric storage device temperature adjustment circuit is stopped; an equipment cooling circuit that cools, with a second coolant, the equipment that needs cooling, and that is capable of switching between a state in which the second coolant is introduced into the electric storage device temperature adjustment circuit and a state in which the introduction of the second coolant into the electric storage device temperature adjustment circuit is stopped; a lead-out switching valve that is capable of switching between an engine-side lead-out position in which the first coolant located inside the electric storage device temperature adjustment circuit is led out to the engine cooling circuit, and an equipment-side lead-out position in which the second coolant located inside the electric storage device temperature adjustment circuit is led out to the equipment cooling circuit; an electric storage device temperature sensor detecting the temperature of the electric storage device; and control means for controlling operation of the warm-up switching valve, the equipment cooling circuit, and the lead-out switching valve in such a manner that the second coolant or the first coolant after cooling the engine selectively flows inside the electric storage device temperature adjustment circuit, according to whether the electric storage device needs to be warmed up or cooled, which is determined on the basis of the temperature of the electric storage device detected by the electric storage device temperature sensor.