Patent attributes
Provided is a hybrid construction machine capable of preventing overcharge, comprising: an engine; a generator-motor; a hydraulic pump; a hydraulic actuator to be operated by the hydraulic pump as a hydraulic pressure source; an actuator regeneration section to make a regenerative action of generating actuator regenerated-electric-power through return fluid from the hydraulic actuator; an electric storage device; a charging-rate detector; and a control section. The control section performs: causing the electric storage device to be charged with electric power generated by the generator-motor and the actuator regenerated-electric-power; causing the generator-motor to make a motor action through electric power stored in the electric storage device to assist the engine; and a regeneration control including stopping the generator action and restricting the actuator regenerated-electric-power, when a detected charging rate of the electric storage device is not smaller than a preset charging-rate limitation value.