| 摘要 |
PROBLEM TO BE SOLVED: To reduce the operating sound of a relief valve which is for example applicable to an electric automobile, and in this case, is used in a hydraulic pump of electric motor drive type to serve as an oil pressure source of a power steering device. SOLUTION: At relieving, a spool 54 accommodated in a valve hole 52 in a sleeve 53 moves so that the oil on the high pressure side is relieved from the hole 52 to a low pressure, ring-shaped oil chamber 83 via a relief path 61 and a ring-shaped gap S to serve as a throttle. The gap S is partitioned by a cylindrical member 63 surrounding the periphery of the sleeve 53. In relieving, the relief path 61 with the outlet throttled gets the intermediate pressure to generate a damping effect. |
