US 7,513,233 B2
Variable valve timing controller for internal combustion engine
Kazuki Ichimura, Anjo (Japan); and Yasuo Hirata, Chita-gun (Japan)
Assigned to Denso Corporation, Kariya (Japan)
Filed on Jul. 11, 2007, as Appl. No. 11/822,927.
Claims priority of application No. 2006-209382 (JP), filed on Aug. 01, 2006.
Prior Publication US 2008/0029050 A1, Feb. 07, 2008
Int. Cl. F01L 1/34 (2006.01)
U.S. Cl. 123—90.17  [123/90.15; 123/347; 464/160] 5 Claims
OG exemplary drawing
 
1. A variable valve timing controller for an internal combustion engine having a hydraulic variable valve timing device which hydraulically varies a valve timing of an intake valve and/or an exhaust valve of the internal combustion engine, comprising:
a control mode switching means for switching a control mode of the hydraulic variable valve timing device between a reference timing control mode in which a hydraulic pressure is controlled to a specified value so that an actual valve timing is brought into a reference timing, and a feedback control mode in which a hydraulic pressure is feedback controlled so that a difference between the actual valve timing and a target valve timing is decreased, wherein
the control mode switching means switches the control mode of the variable valve timing device to the reference timing control mode, when the rotating speed of the internal combustion engine is greater than or equal to a specified value.