| 摘要 |
<p>PURPOSE:To make a fast response and decrease a peak pressure in a relief valve by a method wherein a piston poppet and a pilot poppet are contacted with each other. CONSTITUTION:When the pressure in a supply port 1 is higher than a predetermined pressure or force of a pilot spring 14, the pressure is acted upon the spring 14 via the piston poppet 7 and the pilot poppet 13. Then, the poppet 13 is displaced in a leftward direction to release a pressure in a back pressure chamber 11 into a relief port 2, so that the pressure in the back pressure chamber 11 may be decreased. As a result, the relief valve poppet 4 is displaced in a leftward direction to communicate the passage ports 6a, 6b of a check poppet 3 with each other and the pressure at the port 1 is released to the port 2. When the pressure at the port 1 is equal to the desired pressure, the poppet 13 is returned back to abut against a valve seat 13a, thereby a communication between the back pressure chamber 11 and the port 2 is blocked, a pressure in the back pressure chamber 11 is increased by a hydraulic oil from the port 1 and then the poppet 4 is returned back to its original position.</p> |
