Patent ID: 8347918

Claim:
A solenoid valve apparatus comprising: a solenoid valve having a spool that is constituted by a shaft-shaped member inserted slidably into a cylindrical hollow portion and formed so as to define a pressure regulating chamber for regulating and outputting a fluid pressure supplied from a fluid pressure source and a feedback chamber into which the regulated output pressure is led, and an electromagnetic portion that drives the spool by using an electromagnetic force, the solenoid valve being formed with a pump chamber defined adjacent to the feedback chamber by the hollow portion and the spool so as to function as an electromagnetic pump that suctions and discharges a working fluid in accordance with generation and cancellation of the electromagnetic force from the electromagnetic portion; and a switching device that switches between a first state in which the working fluid in the pump chamber is discharged when the solenoid valve functions as a regulator valve and a second state in which discharge of the working fluid from the pump chamber is prohibited when the solenoid valve functions as the electromagnetic pump.