FLUID-PRESSURE CIRCUIT AND WORKING MACHINE

摘要

PROBLEM TO BE SOLVED: To improve a response of a fluid-pressure circuit having a regulating means for regulating a pilot pressure signal from an operation device to a control valve. SOLUTION: The control valve 54 to control operating fluid supplied to a hydraulic actuator 55 is remotely controlled by the pilot pressure signal generated by manually operating the pilot valve 58. The pilot pressure signal input from the pilot valve 58 to the control valve 54 is regulated by an electromagnetic proportional valve 64 that is activated by an external control signal. A by-pass means 65 is arranged in parallel with the electromagnetic proportional valve 64 so as to move the pressure remaining at the control valve 54 side relative to the electromagnetic valve 64 to the pilot valve 58 side relative to the electromagnetic valve 64. The by-pass means 65 is connected to a by-pass passage 66 to be in parallel with the electromagnetic valve 64. The by-pass passage 66 has a check valve 67 therein for allowing pilot oil to move from the control valve 54 side relative to the electromagnetic valve 64 to the pilot valve 58 side. COPYRIGHT: (C)2004,JPO