CONTROL OF AN ELECTROMAGNETIC STEERING VALVE OF A CAMSHAFT PHASER

摘要

The movable valve apparatus (1) includes the movable valve mechanism (10), the hydraulic pressure control valve (12), and the controller (14). The movable valve mechanism (10) changes the opening/closing timing of an air intake or exhaust valve depending on the supplied hydraulic pressure of the working fluid. The hydraulic pressure control valve (12) adjusts the supplied hydraulic pressure depending on the working condition of the spool (40). The controller (14) controls the solenoid (44) that drives the spool (40). When it is determined that the spool (40) is in the returning state, in which the spool (40) starts moving toward the initial position, the foreign object removal operation is executed. During the foreign removal operation, the spool (40) temporarily reciprocates in order to remove foreign objects in the hydraulic pressure control valve (12).