摘要:
In a state wherein a solenoid switching valve 23 in a gas passage 22 in communication with air chambers 16 and 17 is closed, an assist device 12 produces an assisting driving force by compression or expansion of a gas as a knee joint (specific joint) 8 of a leg 3 bends or stretches, and applies the produced assisting driving force to the knee joint 8. In a valve-open state of the solenoid switching valve 23, no assisting driving force is produced. The solenoid switching valve 23 is constructed of a solenoid switching valve having a self-holding feature, and installed in the gas passage 22 such that a pressure difference between air chambers 16 and 17 acts in a valve closing direction of a valve element in a predetermined period during which the solenoid switching valve 23 is closed. This arrangement effectively reduces the power consumption of the solenoid switching valve by a simple construction.