| 摘要 |
PURPOSE:To improve the responsiveness at every load condition and extensive rotational area by comparing discharge hydraulic pressure with the target one, and according to the compared result, commanding a duty value in which control hydraulic pressure turns to maximum or minimum. CONSTITUTION:A variable displacement vane pump has a control piston 28 partitioning off a control chamber 29 in a gap with a pump cover C, and this piston 28 receives control hydraulic pressure being fed to the control chamber 29 via a feedback passage 37, rocking around a fulcrum 28a, and it displaces a cam ring against a spring 27, whereby an eccentric value in a gap with a rotor 22, namely, discharge hydraulic pressure is controlled. The control hydraulic pressure is generated by a solenoid duty valve 31 being controlled by a control unit 33 on the basis of a driving state in a vehicle. In this case, the discharge hydraulic pressure is compared with the target one, and when the discharge hydraulic pressure is more than the target one, the control hydraulic pressure becomes maximized. When it is less than the target hydraulic pressure, each duty value in which the control hydraulic pressure becomes minimized, is commanded. |
