| 摘要 |
<p>PURPOSE:To improve steering feeling by opening a bypass valve for bypassing oil to the control valve on a power steering apparatus when a steering wheel is set at the neutral position and the steering torque after a certain time lowers below a prescribed value. CONSTITUTION:When a steering wheel 15 is operated, a switch 21 is turned ON to allow a solenoid valve 7 to close a bypass passage 6, and the compressed oil is supplied into a control valve 4. If the steering wheel 15 is turned in the opposite direction in this state, the switch 21 is turned OFF once with the wheel 15 at the neutral position, but the conduction current to the solenoid valve 7 maintains the conduction state for a certain time because of a delay circuit 25. If the wheel 15 is turned in the opposite direction within the above-mentioned certain time, and the switch 21 is turned ON again, the conduction to the solenoid valve 7 is continued without being suspended. If the switch 21 is not turned ON after a certain time is lapsed after switching off, the conduction to the solenoid valve 7 is cut off, and the bypass passage 6 is opened.</p> |
