Patent ID: 8042503
Filing Date: 2011-10-25
Classification: F01L,F02D,F02M,Y02T

Abstract:
1. A variable valve timing apparatus provided in an engine having a plurality of cylinder groups, said variable valve timing apparatus comprising: a changing mechanism provided corresponding to each of said plurality of cylinder groups, each for changing a timing of opening/closing at least one of an intake valve and an exhaust valve in the corresponding cylinder group; reference position learning means provided corresponding to each said changing mechanism, for generating an operation command to an actuator of corresponding said changing mechanism so that said opening/closing timing is changed to a prescribed timing when reference position learning is instructed, and when said opening/closing timing reaches said prescribed timing, for learning a reference of said opening/closing timing in response; learning completion confirming means for confirming whether said reference position learning by said reference position learning means has been completed in every said changing mechanism or not; and control start limiting means for inhibiting, in each said changing mechanism, start of opening/closing timing control for changing said opening/closing timing following a successively set target value, until it is confirmed by said learning completion confirming means that said reference position learning has been completed in all said changing mechanisms.