| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydraulic power steering system that can protect a pump drive motor and a drive circuit thereof against overheating and enhance a steering feeling.SOLUTION: A valve opening command value limit unit computes a valve opening limit value &thetas;on the basis of a detected temperature T by a temperature sensor (S1). When the absolute value |&thetas;*| of a valve opening command value &thetas;* is larger than the valve opening limit value &thetas;(S2-YES), the valve opening command value limit unit determines whether the valve opening command value &thetas;* is equal to or higher than 0 or not (S4). When the valve opening command value &thetas;* is equal to or higher than 0 (S4-YES), the valve opening command value limit unit outputs the valve opening limit value &thetas;as the valve opening command value &thetas;* (S5), and when the valve opening command value &thetas;* is less than 0 (S4-NO), the valve opening command value limit unit outputs a value -&thetas;obtained by reversing a sign of the valve opening limit value &thetas;as the valve opening command value &thetas;B* (S6). |
