To reduce stress applied to a plate spring member used in fixing a solenoid without increas in size of the device so as to heighten the reliability and durability, and eliminate an extra working process for positioning the plate spring member so as reduce the cost.

A plate spring member 3 for regulating the movement of a solenoid by designated preset load is interposed between the assembling face of the housing side and a set of solenoids 23, 24 on the casing side, the plate spring member 3 is disposed extending over two solenoids, the central part in the longitudinal direction is bent substantially like a V-shape as a support part 31 brought into contact with the assembling face, and notch parts 31, 32 which can be positioned and installed on the outer peripheries of both valve dome parts 12, 13 where both solenoids respectively pass are formed on both end parts of the plate spring member 3. Both end parts of the plate spring member 3 where the notch parts 31, 32 are formed are taken as input parts 34, 35 brought into contact with the respective solenoids 23, 24 under designated preset load.