Patent ID: 7174887
Filing Date: 2007-02-13
Classification: F01L,F02D,Y02T

Abstract:
1. A variable valve system, comprising: a variable valve mechanism for changing the operating angle and/or lift amount of a valve body in accordance with the rotation position of a control shaft; a rotary drive mechanism for rotating said control shaft; drive mechanism control means for controlling said rotary drive mechanism so that the rotation position of said control shaft changes within a normal rotation range during a normal operation; a stopper for mechanically restricting the rotation of said control shaft outside said normal rotation range; a rotation angle sensor for changing an output in accordance with the rotation position of said control shaft; learning time drive mechanism control means for driving said rotary drive mechanism under predefined conditions until the rotation of said control shaft is restricted by said stopper; restricted output detection means for detecting the output of said rotation angle sensor while the rotation of said control shaft is restricted by said stopper; and reference output learning means for learning the reference output of said rotation angle sensor in accordance with the output detected by said restricted output detection means.