Valve opening/closing timing control device

摘要

A valve opening/closing timing control device includes: a driving side rotational member; a driven side rotational member; a retarded angle chamber and an advanced angle chamber; a lock mechanism; and a spiral spring providing a biasing force in a predetermined phase direction in a retarded angle region of a relative rotational phase of the driven side rotational member to the driving side rotational member from a most retarded angle phase to a predetermined phase, and not providing the biasing force to a most advanced angle phase from the predetermined phase.