| 摘要 |
<p>A safety valve comprising a sleeve (1) having a high pressure port (11) and a low pressure port (12), a valve seat (2) and a poppet (3) slidably fitted in the sleeve in such a manner as to be brought into abutment with each other and constituting a seat portion to establish and/or block a communication between the high pressure port and the low pressure port, and a spring (7) for pressing the popper (3) against the valve seat (2), wherein the poppet is pushed by virtue of a difference between the pressure of a high pressure oil at the high pressure port acting on a pressure receiving surface of the poppet and the spring force of the spring that resists the pressure so that the seat portion is opened to relieve the high pressure oil to the low pressure port, the safety valve further comprising a damper chamber (A) formed between the sleeve and the valve seat in such a manner that the capacity thereof is reduced when the valve seat slides against the spring and a restriction portion (35) allowing the damper chamber (A) to communicate with the low pressure side, the restriction portion being constructed such that the flow area thereof is reduced when the valve seat slides against the spring, while the flow area is increased when the valve seat is caused to slide in an opposite direction by the spring. <IMAGE></p> |
