| 摘要 |
<p>A hydraulic power unit for a vehicle comprises a motor (1), a pump (3) to be driven by the motor to pump up an oil stored in an oil tank (7), a gas filling type accumulator (5) connected to the pump, a pressure sensor (25) disposed at a portion near an outlet port of the accumulator for detecting a pressure of the oil in the accumulator, a control unit (17) operatively connected to the pressure sensor and a relay (19) opertively connected to the control unit for controlling an operation of the motor. In the control unit (17), a rate of change of the pressure of the oil detected by the pressure sensor (25) is calculated with respect to transition of time, an inflection point at which the rate of change of the oil pressure at a time of control start time or control stop time of the hydraulic power unit is maximumly changed is obtained, an oil pressure at the inflection point is calculated, the oil pressure at the inflection point is compared with a predetermined oil pressure, and a fact as to whether or not the oil pressure at the inflection point reaches the predetermined oil pressure is discriminated. <IMAGE></p> |
