Valve opening/closing timing control device

A valve opening/closing timing control device comprising:

• a driving side rotator which synchronously rotates with a crankshaft of an internal combustion engine;
• a driven side rotator which is coaxially disposed with a rotation axis of the driving side rotator and integrally rotates with a valve opening/closing camshaft;
• an advance chamber and a retard chamber which are formed between the driving side rotator and the driven side rotator;
• a lock mechanism which includes a lock member capable of engaging with a recessed portion formed on one of the driving side rotator and the driven side rotator, and provided in the other of the driving side rotator and the driven side rotator;
• and
• a connecting bolt which is coaxially disposed with the rotation axis and connects the driven side rotator to the camshaft,
• wherein the connecting bolt includes an internal space which is coaxially formed with the rotation axis, and an advance port communicating with the advance chamber, a retard port communicating with the retard chamber, and a lock port communicating with the recessed portion are formed as through-holes connecting the internal space and an outer periphery to each other,
• a valve unit is configured to accommodate a spool to be movable in a direction along the rotation axis in the internal space of the connecting bolt, the spool including an internal flow path through which a fluid is supplied in a supply direction of the fluid along the rotation axis, and,
• in the spool, a lock holding check valve suppressing a backflow of a working oil from the lock port is disposed between a first supply point of the internal flow path and a second supply point of the internal flow path downstream of the first supply point in the supply direction, the first supply point being a point at which the fluid is capable of being supplied from the internal flow path to the advance port and the retard port, the second supply point being a point at which the fluid is capable of being supplied from the internal flow path to the lock port while being blocked from fluid communication with the advance port or the retard port by the lock holding check valve when the lock holding check valve is closed.