| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent sensitive operation of a solenoid type pilot valve by sufficiently reducing the diameter of a damping orifice, without causing nonconformities such clogging of a foreign substance. SOLUTION: A spool valve 36 discharging hydraulic fluid of a feed passage in a circuit track to a drain passage 43, in response to the advancing/retreating operation, is provided, a fixed orifice 45 is provided in a communicating passage 44 communicating a high pressure chamber 41 with a low pressure chamber 42 in the front/rear of the spool valve 36, and a solenoid pilot valve 47 is provided in a pilot drain passage 46, communicating with the low pressure chamber 42. A first filter 53 is provided in the upstream part of the fixed orifice 45, a damping orifice 64 preventing the sensitive operation of the pilot valve 47 is provided in the drain passage 46, and a second filter 66 is provided on the upstream part.</p> |
