| 摘要 |
PURPOSE:To reduce the size of a switching valve by applying specified limitation on switching control of a switching valve used for variation of a delivery am ount, in a delivery amount variable fluid pressure feeding device. CONSTITUTION:A first return passage 44 is branched on the upper stream side of a first check valve 39A to a first feed passage 38A on the first pump 34A side. A second return passage 46 is branched on the upper stream side of a second check valve 39B to a second feed passage 38B on the second pump 34B side a delivery amount of which is relatively low. A first switching valve 42 to communicate either the return passage 44 or 46 to a third return passage 48 through a tank 30 and a second switching valve 43 to bring the third return passage 48 into a communicating or disconnecting state and are provided. The switching valves 42 and 43 are controlled by means of a delivery passage control circuit passage 50, and control is effected such that the second switching valve 43 is switched from a disconnecting state to a communicating state in a state that the first switching valve 42 communicates the second return passage 46 to the third return passage 48. |
