| 摘要 |
PURPOSE:To always obtain a fixed damping effect by forming spaces between each outer periphery of flange portions formed on both ends of a spool of a pilot switch valve and each inner periphery of pilot pressure chambers to which the flange portions face. CONSTITUTION:In a switch valve where a valve body (a) comprising a body 12 and covers 13, 14 fixed to both ends thereof incorporates a spool 15 in such a manner as to freely slide, circular grooves 35, 36 are formed on both ends of the spool 15, and the outer end portions of the respective grooves 35, 36 are flange portions 58, 59. The flange portions 58, 59 are projected into small-diameter holes 21, 22 formed on the covers 13, 14, thereby to partition pilot pressure chambers 51, 52. In this case, the outside diameters of the flange portions are set smaller than the inside diameters of the small-diameter holes to form spaces 41, 42 therebetween. Thus, the respective chambers 51, 52 communicate with relay chambers 53, 54 connected to a pump of a tank through spaces 41, 42. |
