Valve opening and closing timing control device

A valve opening and closing timing control device comprising:

• a drive-side rotary body that rotates synchronously with a crankshaft of an internal combustion engine;
• a driven-side rotary body that is arranged coaxially with a rotation axis of the drive-side rotary body and that rotates integrally with a valve opening and closing camshaft of the internal combustion engine;
• a fluid pressure chamber defined between the drive-side rotary body and the driven-side rotary body;
• an advance chamber and a retard chamber defined by partitioning the fluid pressure chamber with a partition portion provided in at least one of the drive-side rotary body and the driven-side rotary body;
• an intermediate lock mechanism that selectively switches between a lock state in which a relative rotation phase of the driven-side rotary body with respect to the drive-side rotary body is restrained to an intermediate lock phase between a most advanced phase and a most retarded phase and a lock release state in which the restraint of the intermediate lock phase is released by supply and discharge of a working fluid;
• an advance flow path that allows a flow of the working fluid to be supplied to and discharged from the advance chamber;
• a retard flow path that allows a flow of the working fluid to be supplied to and discharged from the retard chamber;
• a control valve including a spool that is in a first position when a power supply amount is zero and is moved to a second position different from the first position when the power is supplied;
• and
• a phase control unit that moves a position of the spool by controlling the power supply amount to the control valve to supply the working fluid to and discharge the working fluid from the advance chamber and the retard chamber to displace the relative rotation phase, wherein
• when the spool is in the first position, the intermediate lock mechanism is set to the lock state and a state in which the working fluid is discharged from any one of the advance chamber and the retard chamber and the working fluid is supplied to the other one of the advance chamber and the retard chamber,
• when the spool is in the second position, the intermediate lock mechanism is set to the lock release state and a state in which the working fluid is supplied to any one of the advance chamber and the retard chamber and the working fluid is discharged from the other one of the advance chamber and the retard chamber, and
• when the intermediate lock mechanism is in the lock release state and the relative rotation phase is a phase that is displaced in a direction toward the intermediate lock phase when the power supply amount to the control valve is maximized, and if a rotation speed of the internal combustion engine becomes less than a predetermined value, the phase control unit controls the power supply amount to the control valve so that the relative rotation phase is displaced in the direction toward the intermediate lock phase.