| 摘要 |
PURPOSE:To restrain the recovery of liquid pressure to prevent impact upon a pedal, by moderating the deenergization of a solenoid in an auto-stop valve in association with a gradual decrease in energizing current upon release of the holding of liquid pressure so that the valve is moderately opened. CONSTITUTION:An AND circuit 22 is turned on in accordance with a vehicle stopping condition detection signal from a vehicle speed sensor 20 and an inverted signal of an accelerator pedal release signal from an accelerator pedal 21. When the AND circuit 22 is turned on, transistors Q1, Q2 in an auto-stop valve drive control circuit 23 are turned on to energize a solenoid 18 so that an auto- stop valve is turned into its liquid pressure holding condition. When the accelerator pedal 21 is depressed upon starting of a vehicle, the AND circuit is turned off so that the transistor Q1 is also turned off. Therefore, the charge of a capacitor C is initiated, resulting in that a predetermined bias current iB which is determined in accordance with the resistance values of resistors R1, R2, etc. runs, but gradually decreases. Accordingly, the energization of the solenoid 18 is moderately decreased to gradually open the valve. |
