Patent ID: 7171943

Claim:
A control apparatus for an internal combustion engine comprising: an intake valve that is driven in synchronization with the rotation of an internal combustion engine at timing with a predetermined phase difference thereby to open and close an intake pipe leading to a combustion chamber of said internal combustion engine; a variable valve timing mechanism that continuously adjusts the opening and closing timing of said intake valve to an advance angle side and a retard angle side with reference to a predetermined basic timing; a variable valve timing control device that includes an operating state detection part for detecting an operating state of said internal combustion engine, and serves to drive and control said variable valve timing mechanism based on said engine operating state; a rotational speed detection part that detects a rotational speed of said internal combustion engine; and an intake negative pressure detection part that detects an intake negative pressure in said intake pipe varying in accordance with an adjustment of the opening and closing timing of said intake valve; wherein said variable valve timing control device comprises: a basic timing correction permission part that permits a correction operation for said basic timing when said operating state of said internal combustion engine is in a fuel cut-off state; a target intake negative pressure setting part that determines, based on said rotational speed of said internal combustion engine, a target intake negative pressure that should be set as an initial state of said correction operation for said basic timing when said correction operation for said basic timing is permitted; an intake air amount adjustment part that adjusts an amount of intake air sucked into said combustion chamber so as to make said intake negative pressure detected by said intake negative pressure detection part coincide with said target intake negative pressure; a correction time driving control part that controls said variable valve timing mechanism so as to be driven to advance after said intake negative pressure is made to coincide with said target intake negative pressure by means of said intake air amount adjustment part; and a basic timing correction part that corrects said basic timing based on the state of said variable valve timing mechanism when an intake negative pressure change index calculated by using said intake negative pressure exceeds a predetermined value during the driving and controlling operation of said correction time driving control part.