| 摘要 |
PURPOSE:To obtain the stabilized hydraulic pressure by controlling the solenoid exciting current by a solenoid valve drive circuit into which the pulse signal having a controlled duty ratio is input and receiving the variation of said oil pressure by a pressure control valve heating a throttle part and outputting the oil pressure corresponding to the above oil pressure. CONSTITUTION:When the pulse signal whose duty ratio is controlled by a microcomputer 1 is input into a solenoid valve drive circuit 2, electric current is supplied to the solenoid of a solenoid valve 4, passing through a wire 3, only in the case when the pulse signal is at high level. Then, an output side pressure port 5 and a drain flowout pressure port 6 communicate to each other, and the pressure is reduced to zero. When electric current is not fed, the pressure port 5 communicates to a supplied oil pressure inflow port 7, and an indication oil pressure is output from the pressure port 5, and the controlled oil pressure equal to said indication oil pressure is output from a pressure control valve 8. |
