FALL PREVENTION VALVE DEVICE WITH REGENERATIVE FUNCTION

摘要

PROBLEM TO BE SOLVED: To prevent deterioration of relief function of an overload relief valve assembled to a fall prevention valve device and adopt common parts in the fall prevention devices with regenerative function and without regenerative function. SOLUTION: A work port 21 is opened an oil passage 28 between a load holding check valve 24 and a proportional sheet valve 25 serving as a returning side throttling element and a load holding check valve. An oil passage 38 branched from the oil passage 28 is communicated to an inlet of an overload relief valve 26. An outlet port 30 of the proportional sheet valve 25 is interrupted from an outlet port 22 of a valve block 23 by means by means of a wall 23a of the valve block. A regenerating oil passage 50 on which a regenerating check valve 27 is arranged and a regeneration adjusting oil passage 51 are branched from the outlet port 30 of the proportional valve. A returning oil passage 52 is formed so as to be opened to the outlet port of the valve block. A regeneration adjusting device 53 is arranged outside the valve block for controlling communication between the oil passages 51 and 52.