Patent ID: 9574681
Date: 2017-02-21
CPC Classifications: F01L,F16K

Claim:
1. A variable valve timing control apparatus comprising: a driving-side rotation member rotating in synchronization with a crankshaft of an internal combustion engine; a driven-side rotation member arrange to be coaxial with the driving-side ration member and rotating in synchronization with a camshaft for opening and closing a valve of the internal combustion engine; an intermediate lock mechanism including first and second lock members provided at one of the driving-side rotation member and the driven-side rotation member to be movable, first and second recess portions provided at the other of the driving-side rotation member and the driven-side rotation member, and a guide groove continuously formed from a portion of at least one of the first and second recess portions, the intermediate lock mechanism being selectively switchable between a locked state in which a relative rotation phase of the driven-side rotation member relative to the driving-side rotation member is locked at an intermediate lock phase between a most advanced angle phase and a most retarded angle phase because of the first and the second lock members moving to be fitted to the first and second recess portions respectively and an unlocked state in which the locked state is released because of the first and the second lock members separating from the first and second recess portions respectively, a restriction of the relative rotation phase which prevents the relative rotation phase from changing in both an advanced angle direction and a retarded angle direction at the intermediate lock phase being achieved by a fitting between a single one of the first and the second lock members and a single one of the first and second recess portions; a sensor detecting whether or not the relative rotation phase is changed; a control portion controlling a relative rotation of the driven-side rotation member relative to the driving-side rotation member; the control portion performing a control for changing the relative rotation phase based on a request for changing the relative rotation phase from the unlocked state to the locked state so that the relative rotation phase is changed until a first stop state is established, the first stop state in which the change of the relative rotation phase is stopped, in a state where the relative rotation phase is in the unlocked state and one of the first and second lock members configured to be fitted to one of the first and second recess portions at which the guide groove is formed is positioned relative to the one of the first and second recess portions at which the guide groove is formed at a side opposite from a side where the guide groove is formed; and the control portion performing a control for changing the relative rotation phase by reversing a change direction of the relative rotation phase after the first stop state is established so that the relative rotation phase is changed until a second stop state is established, the second stop state in which the change of the relative rotation phase is stopped.