| 摘要 |
PURPOSE:To reduce an energy loss and enable the use of a fluid pump of relatively low cost, by causing a prime mover to drive the fluid pump to supply assisting energy only when it is necessary for power steering. CONSTITUTION:In a rack-pinion-type power steering gear, a detector 20 for the steering torque of a steering shaft 12 and the direction of its rotation is provided between the shaft and an output shaft 13. An electromagnetic changeover valve 43 for by-passing and a fluid pump 42, which is driven by a prime mover 40 through a power transmission mechanism 30, are provided. The mechanism 30 functions so that the rotation of an input shaft 31 is transmitted to a drive shaft 32 without changing the direction of the rotation or after changing it, through the action of a pair of solenoids provided in the mechanism, and that the rotation of the drive shaft 32 can be stopped. The solenoids are controlled by a circuit 45. The electromagnetic changeover valve 43 is opened except in steering, to connect both the pressure chambers R1, R2 of a power cylinder 14 to each other. |
