Patent ID: 6135078
Filing Date: 2000-10-24
Classification: F01L,F02D

Abstract:
A variable valve timing control apparatus for an internal combustion engine, comprising:a driven shaft driven by a driving force of the internal combustion engine;a cam provided on said driven shaft, said cam having a profile for opening or closing an associated valve of the internal combustion engine, said profile being variable from a high lift curve to a low lift curve in accordance with a movement of an engaging point between said cam and said associated valve in an axial direction of said driven shaft;a driving mechanism for shifting said driven shaft in said axial direction;a phase adjusting mechanism for adjusting the phase of said driven shaft relative to a driving shaft of the internal combustion engine;at least one angle detecting tooth provided on a cylindrical surface of said driven shaft for detecting a rotational angle of said driven shaft;at least one shift detecting tooth provided on said cylindrical surface of said driven shaft for detecting a shift amount of said driven shaft in said axial direction, said shift detecting tooth being inclined at a predetermined angle with respect to an axis of said driven shaft so as to provide angularly advanced and retarded portions in a rotational direction of said driven shaft;a sensor for generating sensing signals responsive to said angle detecting tooth and said shift detecting tooth; andsaid sensor facing said angularly advanced portion of said shift detecting tooth when said low lift curve of said cam is selected in a low-speed operating condition of said internal combustion engine and facing said angularly retarded portion of said shift detecting tooth when said high lift curve of said cam is selected in an engine operating condition other than said low-speed operating condition.