| 摘要 |
The invention relates to a relief valve and intends to provide a relief valve which can reduce the difference between the dynamic set pressure and static set pressure of the relief pressure and its variation. An internal circumferential surface of the pilot valve element 214 to which a support 227 is inserted is expanded to form a sub valve chest 231, a support and sub valve element 232 externally fitted to the sealing member 229 is arranged in this sub valve chest 231, the clearance between the inner circumferential surface of the sub valve element 232 and the support 227 is sealed with the sealing member 229, and at the same time the sub valve element 232 is pressed against the sub valve seat 238 formed in the inner circumferential surface of the pilot valve element 214 by oil pressure exerted on the sub valve element 232 from the pressure chamber 208 side to seal the clearance between the sub valve element 232 and the support 227. The sealing member 229 is not allowed to come in direct contact with the pilot valve element 214 to prevent the sealing member 229 deformed by oil pressure from applying resistance to the move of the pilot valve element 214.
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