Variable valve lift apparatus

Abstract

A variable valve lift apparatus of an engine may include an inner tappet, an outer tappet centrally receiving the inner tappet, a latching unit inserted in the inner tappet and operated by a hydraulic pressure so as to selectively engage the inner and outer tappets by operation, and a protruding member that is coupled to an upper surface edge of the outer tappet so as to protrude outward from an exterior circumference of the outer tappet, and is vertically slidable along a sliding groove of a cylinder head.

What is claimed is: 
     
         1 . A variable valve lift apparatus of an engine, comprising:
 an inner tappet;   an outer tappet centrally receiving the inner tappet;   a latching unit within the inner tappet and operated by a hydraulic pressure so as to selectively interengage the inner and outer tappets; and   a protruding member that is coupled to an upper surface edge of the outer tappet protruding outward from an exterior circumference of the outer tappet, and is vertically slidable along a sliding groove of a cylinder head.   
     
     
         2 . The variable valve lift apparatus of  claim 1 , wherein a supporting recess having a predetermined width is formed across a center of an uppermost portion of the outer tappet. 
     
     
         3 . The variable valve lift apparatus of  claim 2 , wherein an exterior diameter of the uppermost portion of the inner tappet is smaller than or equal to an exterior diameter of the outer tappet. 
     
     
         4 . The variable valve lift apparatus of  claim 3 , wherein a cross-section of the inner tappet is generally T-shaped. 
     
     
         5 . The variable valve lift apparatus of  claim 3 , wherein the protruding member comprises:
 a first portion coupled with an edge of the supporting recess; and   a second portion perpendicularly connected to the first portion and protruding outward from the exterior circumference of the outer tappet.   
     
     
         6 . The variable valve lift apparatus of  claim 5 , wherein a cross-section of the protruding member is generally L-shaped. 
     
     
         7 . The variable valve lift apparatus of  claim 5 , wherein a mounting groove is formed at the edge of the supporting recess so as to allow coupling of the first portion. 
     
     
         8 . The variable valve lift apparatus of  claim 7 , wherein a bottom surface of the first portion coincides with a bottom surface of the supporting groove. 
     
     
         9 . The variable valve lift apparatus of  claim 5 , wherein an exterior of the second portion protruding from the exterior circumference of the outer tappet is round. 
     
     
         10 . The variable valve lift apparatus of  claim 5 , wherein an exterior of the second portion protruding from the exterior circumference of the outer tappet is polygonal. 
     
     
         11 . The variable valve lift apparatus of  claim 1 , wherein the protruding member is fixed to the outer tappet by pressing, welding, bonding, bolting, or fusion.