APPARATUS FOR REDUCING AMOUNT OF LEAKAGE

摘要

PROBLEM TO BE SOLVED: To provide an apparatus for reducing the amount of leakage which restrains colliding sound from arising when a poppet valve is opened and which is capable of securely opening every time the poppet valve is operated. SOLUTION: An anti-drift valve 10 comprises a passage capable of making a back pressure chamber 11 of the poppet valve 8 communicate with a drain line 12 connected to a tank 6, a slidable spool 20 which cuts off the passage when a directional control valve 1 is in neutral position and a restrictor 21 provided in a passage part positioning between the spool 20 and the back pressure chamber 11 of the poppet valve 8, and reduces leakage of high-pressure hydraulic fluid a in line 33 to the tank 6 when the directional control valve 1 is in neutral position. A control means for controlling inflow of the high pressure fluid flowing in the line 33 into the back pressure chamber 11 of the poppet valve 8 when the poppet valve 8 is opened is provided. The control means comprises a sealing member 37 which is disposed between the peripheral side of the poppet valve 8 and the peripheral side of a housing 7 which is opposed to the peripheral side of the poppet valve 8 and in which the poppet valve 8 is slidably housed. COPYRIGHT: (C)2003,JPO