Continuous variable valve lift apparatus

Abstract

A continuously variable valve lift apparatus may include an input unit, a camshaft for receiving rotation from the input unit, wherein one end portion of the camshaft is slidably coupled to the input unit in a longitudinal direction of the camshaft, a controlling unit for controlling a relative position of the camshaft in the longitudinal direction of the camshaft, a slanted cam disposed to the camshaft and a cross-section of which is slanted with a predetermined angle with respect to a longitudinal axis of the camshaft, a mediating unit slanted with substantially the same angle of the slanted cam and pivoting in response to rotation of the slanted cam, and a valve opening unit that is opened/closed in response to the pivoting motion of the mediating unit.

1 . A continuously variable valve lift apparatus comprising:
 an input unit;   a camshaft for receiving rotation from the input unit, wherein one end portion of the camshaft is slidably coupled to the input unit in a longitudinal direction of the camshaft;   a controlling unit for controlling a relative position of the camshaft in the longitudinal direction of the camshaft;   a slanted cam disposed to the camshaft and a cross-section of which is slanted with a predetermined angle with respect to a longitudinal axis of the camshaft;   a mediating unit slanted with substantially the same angle of the slanted cam and pivoting in response to rotation of the slanted cam; and   a valve opening unit that is opened/closed in response to the pivoting motion of the mediating unit.   
     
     
         2 . The continuously variable valve lift apparatus of  claim 1 , wherein the input unit comprises:
 a camshaft sprocket slidably coupled to the one end portion of the camshaft; and   an elastic member disposed between the camshaft sprocket and the camshaft and supplying restoring force to the camshaft toward the controlling unit.   
     
     
         3 . The continuously variable valve lift apparatus of  claim 2 , wherein the elastic member is a spring. 
     
     
         4 . The continuously variable valve lift apparatus of  claim 2 , wherein the one end portion of the camshaft has a shape of an oval cross-section, a polygon, or a spline. 
     
     
         5 . The continuously variable valve lift apparatus of  claim 2 , wherein the camshaft includes a cam connecting portion formed at the one end portion of the camshaft to be camshaft coupled to the camshaft sprocket. 
     
     
         6 . The continuously variable valve lift apparatus of  claim 5 , wherein the cam connecting portion has a shape of an oval cross-section, a polygon, or a spline. 
     
     
         7 . The continuously variable valve lift apparatus of  claim 2 , wherein the input unit further comprises a front journal connected to the camshaft sprocket, and the camshaft are slidably coupled to the front journal in the longitudinal direction of the camshaft. 
     
     
         8 . The continuously variable valve lift apparatus of  claim 7 , wherein the one end portion of the camshaft has a shape of an oval cross-section, a polygon, or a spline. 
     
     
         9 . The continuously variable valve lift apparatus of  claim 7 , wherein the camshaft includes a cam connecting portion formed at the one end portion of the camshaft to be slidably coupled to the front journal of the input unit. 
     
     
         10 . The continuously variable valve lift apparatus of  claim 9 , wherein the cam connecting portion has a shape of an oval cross-section, a polygon, or a spline. 
     
     
         11 . The continuously variable valve lift apparatus of  claim 1 , wherein the controlling unit comprises an eccentric cam that contacts the other end portion of the camshaft for controlling the relative position of the camshaft. 
     
     
         12 . The continuously variable valve lift apparatus of  claim 11 , wherein rotation angle of the eccentric cam is controlled by a control unit. 
     
     
         13 . The continuously variable valve lift apparatus of  claim 1 , wherein the mediating unit comprises:
 a rocker shaft disposed in parallel to the camshaft; and   a rocker lever rotatably coupled to the rocker shaft and slidably contacting the slanted cam.   
     
     
         14 . The continuously variable valve lift apparatus of  claim 13 , wherein the rocker lever is biased toward the camshaft by an elastic member. 
     
     
         15 . The continuously variable valve lift apparatus of  claim 14 , wherein the elastic member is a spring. 
     
     
         16 . The continuously variable valve lift apparatus of  claim 13 , wherein the rocker lever comprises:
 a slanted portion slidably contacting the slanted cam; and   an output portion slidably contacting the valve opening unit.   
     
     
         17 . The continuously variable valve lift apparatus of  claim 16 , wherein the output portion comprises:
 a lift section that generates valve lift in response to pivoting of the rocker lever; and   a zero lift section that does not generate the valve lift, allowing pivoting of the rocker lever.   
     
     
         18 . An passenger vehicle comprising the continuously variable valve lift apparatus of  claim 1 .