Schaltventil

摘要

A crosswise controllable pilot valve for generating a pilot pressure corresponding to an amount of operation of a control lever. This valve has a spool reciprocable within a valve case between a pilot pressure supplying position for interconnecting a pump port and a supply and exhaust port, and an exhaust position for interconnecting a tank port and the supply and exhaust port, and a push rod movable in a first direction within the valve case to move the spool to the supplying position. The push rod includes a cylindrical skirt portion adjacent one end thereof having sliding surfaces for sliding relative to the valve case, and a rod portion adjacent the other end. The skirt portion, rod portion and valve case define a first space, while the skirt portion, spool and valve case define a second space. The first space and second space communicate with each other through oil passages for permitting escape of oil from the first space to the second space or from the second space to the first space during movement of the push rod.