| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power steering system capable of reducing electric power consumption greatly and improving fuel economy. <P>SOLUTION: In this power steering system, oil passages P1, P2 are connected with oil chambers 24, 25 in a power cylinder 20, respectively, and an electric pump unit 30, a reservoir tank 40, and a flow passage controlling mechanism 50 are connected with the oil passages P1, P2 to communicate with them. The controlling mechanism 50 is provided with mechanical valves 51, 52 provided in the oil passages P1, P2 and a differential pressure operation mechanism part 53, which is composed of a rod 53a, a differential pressure piston 53b, and a cylinder 53c and forms pressure chambers 53d, 53e. Each of the pressure chambers 53d, 53e is connected with oil discharge passages 34, 33 communicating with an oil pump 31, respectively. By introducing hydraulic fluid into respective pressure chambers 53d, 53e, flow passage controlling positions of the mechanical valves 51, 52 are switched to communication inhibiting positions. <P>COPYRIGHT: (C)2008,JPO&INPIT |
