| 摘要 |
<p>PURPOSE:To eliminate the delay of response of a holding valve and pilot switching valve by communicating a pilot circuit into which spool switching pilot pressure is introduced and a drain circuit for discharging relief oil and drain with an oil passage provided with a throttle part. CONSTITUTION:A pilot circuit 34' (the circuit leading from an arm remote controlling valve 26 to a pilot pressure receiving portion 17 for switching a spool 16) into which the pilot pressure for switching the spool 16 of a holding valve 11 is introduced and a drain circuit (the circuit communicating with a tank 2'7 through a drain passage 18 and a drain port 19) for discharging relief oil and drain are communicated with each other by an oil passage provided with a throttle portion 42, for example, by a line 43-43'. Thereby, the dead-end state around a pilot port 20 in the pilot circuit 34' can be eliminated. Moreover the problem like the delay of response of the holding valve 11 and the pilot switching valve 23 in operation of the arm remote controlling valve 26 can be eliminated by discharging residual mixed-air.</p> |
