| 摘要 |
<p>PURPOSE:To minimize the labor for adjusting relief pressure by particularly providing only one relief slave valve independently, and by setting it so that the pressure of all the relief master valves is boosted when pilot pressure is applied to the relief slave valve through switch operation. CONSTITUTION:A working relief valve is divided into relief master valves 41a, 41b and a relief slave valve 44. Particularly, only one relief slave valve 44 is provided independently. The upstream side of the only one relief slave valve 44 and plunger chambers 34a and 34b in the back sides of main plungers 28a and 28b of the respective relief master valves 41a and 41b are communicated through check valves 42a and 42b respectively. In this case, all the relief master valves 41a and 41b are set so as to be boosted when pilot pressure is applied to the booster pilot port 45 of the relief slave valve 44 by switching operation. Thus, it is possible to minimize the labor for adjusting the relief pressure.</p> |
