Multiple variable valve lift apparatus

Abstract

A multiple variable valve lift apparatus connected with a valve opening and closing unit which is adapted to rolling-contact one end thereof with a cam and is operated to open or close by a rotation of the cam, and operating to select the cam which is rolling-contacted with the valve opening and closing unit for changing a valve lift, may include a normal cam rolling-contacting with the valve opening and closing unit so as to realize a normal lift of a predetermined valve, and a low cam rolling-contacting with the valve opening and closing unit so as to realize a valve lift which is lower and longer than the normal lift realized by the normal cam, wherein the normal cam or the low cam is selectively rolling-contacted to the valve opening/closing unit according to a driving state.

What is claimed is: 
     
         1 . A multiple variable valve lift apparatus connected with a valve opening and closing unit which is adapted to rolling-contact one end thereof with a cam and is operated to open or close by a rotation of the cam, and operating to select the cam which is rolling-contacted with the valve opening and closing unit for changing a valve lift, the multiple variable valve lift apparatus comprising:
 a normal cam rolling-contacting with the valve opening and closing unit so as to realize a normal lift of a predetermined valve; and   a low cam rolling-contacting with the valve opening and closing unit so as to realize a valve lift which is lower and longer than the normal lift realized by the normal cam;   wherein the normal cam or the low cam is selectively rolling-contacted to the valve opening/closing unit according to a driving state.   
     
     
         2 . The apparatus of  claim 1 , wherein the valve is early opened and is lately closed to compare with the normal lift in the valve lift realized by the low cam. 
     
     
         3 . The apparatus of  claim 1 , wherein the normal lift realized by that the normal cam is rolling-contacted with the valve opening and closing unit is a predetermined valve lift such that efficiency of an engine is improved when a vehicle is driven at a high speed and a normal speed. 
     
     
         4 . The apparatus of  claim 3 , wherein the low cam realizes the valve lift by rolling-contacting with the valve opening and closing unit such that efficiency of an engine is improved when a vehicle is driven at a low speed.