FLUID PRESSURE DRIVING DEVICE FOR CIRCUIT BREAKER

PROBLEM TO BE SOLVED: To provide a fluid pressure driving device for a circuit breaker which reduces cost and improves reliability by suppressing pressure increase during buffering in simple configuration.SOLUTION: The fluid pressure driving device comprises: a contact 2 formed from a movable contactor 2b and a stationary contactor 2a; a rod 3 connected to the movable contactor 2b; a piston 10 which is connected to the rod 3 and installed so as to slide within a cylinder and opens/closes the contact 2; a fluid pressure source 5 which pressurizes and supplies a working fluid; and a control valve for driving the piston 10. The piston 10 separates a supply pressure chamber 12i and a small pressure receiving area chamber 9 communicating to the fluid pressure source 5 at a side connected with the movable contactor 2b from a cylinder control chamber 17 at a side opposite to the side connected with the movable contactor 2b. The control valve controls supply/discharge of the working fluid to/from the cylinder control chamber 17. 【課題】緩衝時の圧力上昇を抑える構成を簡易な構成で成立させ、低コストで信頼性の高い遮断器の流体圧駆動装置を提供する。【解決手段】可動接触子２ｂ及び固定接触子２ａから成る接点２と、可動接触子２ｂに接続されるロッド３と、ロッド３に接続されると共に、シリンダ内を摺動可能に設置され、接点２を開閉動作させるピストン１０と、作動流体を加圧供給する流体圧源５と、ピストン１０を駆動する制御弁とを備え、ピストン１０は、可動接触子２ｂと接続される側の流体圧源５につながる供給圧室１２ｉ及び小受圧面積室９と、可動接触子２ｂと接続される側とは反対側のシリンダ制御室１７とを区分し、制御弁は、シリンダ制御室１７への作動流体の供給排出を制御する。【選択図】図１