HYDRAULIC DRIVING DEVICE OF CIRCUIT BREAKER

摘要

PROBLEM TO BE SOLVED: To miniaturize a hydraulic drive device of a circuit breaker and improve reliability. SOLUTION: The hydraulic drive device 3 comprises a hydraulic cylinder 7 for opening and closing a contact part 70, a control valve for opening a flow passage making the hydraulic cylinder open by a liquid force of the operating liquid, and a control valve for closing the flow passage making the hydraulic cylinder close. The control valve for opening the flow passage has a main control valve 30 for opening the flow passage and a pilot valve 50 for driving the opening main control valve. The control valve for closing the flow passage has has a main control valve 20 for closing the floe passage and a pilot valve 60 for driving the closing main control valve. Each main control valve has a valve seat 25, 35 and valve elements 21, 31 for contacting this valve seat. Each valve is arranged in opposition to each other and the length between the contact sections of the valve element with the valve seat is made longer than the distance between the valve seat sections where each valve element contacts with each valve seat. COPYRIGHT: (C)2005,JPO&NCIPI