バルブタイミング制御装置に用いられる油圧制御機構及び該油圧制御機構のコントローラ

摘要

A hydraulic control unit is configured to switch among a first state where a discharge passage of a pump driven by an internal combustion engine communicates with both a phase-advance passage and a lock passage and simultaneously a phase-retard passage communicates with a drain passage, a second state where the discharge passage communicates with both the phase-retard passage and the lock passage and simultaneously the phase-advance passage communicates with the drain passage, and a third state where the phase-advance passage, the phase-retard passage, and the lock passage all communicate with the discharge passage. The hydraulic control unit is further switchable to a fourth state where the discharge passage communicates with both the phase-advance passage and the phase-retard passage and simultaneously the lock passage communicates with the drain passage.