| 摘要 |
PURPOSE:To absorb a shock by forming a slit on the periphery of a spool and providing the spool with a main passage and also providing a liquid chamber in the back of an unload valve with an opening/closing passage and thus supplying pressurized oil staying in a pump side main passage into a cylinder side passage. CONSTITUTION:Pressured oil supplied to a main passage 5 pushes and opens a check valve 33 and is supplied through a main passage 6 to a cylinder A, which is raised slowly. On the other hand, since a slit 8 is half-opened, a difference in pressure is produced between the front and the rear of the slit 8. High internal pressure of a main passage 4 pushes an unload valve 37 in the right direction up to the position where said internal pressure is balanced with the backpressure of the valve 37. The port of a passage 13 is then half opened. |
