FLUID PRESSURE CLAMP DEVICE WITH INTENSIFYING CIRCUIT

PURPOSE:To cost down a hydraulic instrument and to reduce the consumption power by forming the structure of clamping by feeding a low initial pressure to a clamping cylinder and obtaining the specified clamping power by feeding the pressure higher than the initial pressure simultaneously with the clamp. CONSTITUTION:A low initial pressure is fed via a three way solenoid change- over valve 13 to a clamping cylinder 8, clamping is performed by moving a piston 7, a clamp circuit is cut off by a check valve 15 with a pilot simultaneously with clamping and the surge pressure generated at clamping time is sealed in the circuit. The structure is formed at the same time so as to obtain a specified clamping power by feeding the pressure higher than the initial pressure by intensifying pistons 38, 39 and to operate alternately the intensifying pistons 38, 39 by having a duplicate time by providing them in parallel. Consequently, the need for setting the hydraulic circuit of the whole machine in a high pressure with the clamp power as the reference is eliminated and the cost down of a hydraulic instrument and the reduction in the consumption of the hydraulic driving power can be executed.