| 摘要 |
PROBLEM TO BE SOLVED: To provide a reliable oil pump and a hydraulic circuit for a vehicle, capable of securing a desired delivery pressure of oil without delay after driving.SOLUTION: A relief valve 42 includes a first valve element 51 and a second valve element 52 which are disposed in a relief hole 34 and form two flow passages between a first communication hole and a second communication hole and can selectively switch the flow passages, and a first coil spring 54 and a second coil spring 55 which energize the valve elements 51 and 52 toward a direction closing the first communication hole. The first valve element 51 and the second valve element 52 form a first flow passage so as to guide oil to an open port when the first valve element 51 and the second valve element 52 are pressed by the oil existing in the first communication hole, and the first valve element 51 and the second valve element 52 form a second flow passage so as to guide air to the open port when the first valve element 51 and the second valve element 52 are pressed by the air existing in the first communication hole. |
