Variable valve system

Abstract

The present disclosure relates to a variable valve system applying a continuously variable valve timing apparatus and a two-step type variable valve lift apparatus. The variable valve system may be applied to an engine that a rotational motion of a cam being formed or disposed at a camshaft so as to rotate together with the camshaft is converted to a reciprocating motion of a valve for opening/closing a combustion chamber. The variable valve system may include the two-step type variable valve lift apparatus making a lever motion, and a continuously variable valve timing apparatus changing phase of the camshaft connected with a rotor as the rotor rotates by rotating a vane formed at the rotor. In particular, one end of the valve lift apparatus is rolling-contacted with the cam and the other end is contacted with the valve so as to realize one of two lifts of the valve.

What is claimed is: 
     
         1 . A variable valve system which is applied to an engine being configured that a rotational motion of a cam being formed or disposed at a camshaft so as to rotate together with the camshaft is converted to a reciprocating motion of a valve for opening or closing a combustion chamber, the variable valve system comprising:
 a two-step type variable valve lift apparatus configured to perform a lever motion and configured that one end of the two-step type variable valve lift apparatus is in rolling-contact with the cam and an other end of the two-step type variable valve lift apparatus is in contact with the valve so as to perform one of two lifts of the valve; and   a continuously variable valve timing apparatus configured to change a phase of the camshaft connected with a rotor as the rotor rotates by rotating a vane formed at the rotor so as to selectively change opening or closing timing of the valve.   
     
     
         2 . The variable valve system of  claim 1 , wherein the variable valve system is applied to an intake side of the engine and the valve is an intake valve which is operated so as to supply intake air into the combustion chamber. 
     
     
         3 . The variable valve system of  claim 1 , wherein the variable valve system is applied to an exhaust side of the engine and the valve is an exhaust valve which is operated so as to discharge exhaust gas from the combustion chamber. 
     
     
         4 . The variable valve system of  claim 1 , wherein the continuously variable valve timing (CWT) apparatus is an electric continuously variable valve timing apparatus which is operated electrically. 
     
     
         5 . The variable valve system of  claim 1 , wherein the continuously variable valve timing apparatus is an intermediate phase continuously variable valve timing (CVVT) apparatus which is operated by hydraulic pressure so as to have a parking position which is an intermediate phase between a maximal advance position and a maximal retard position. 
     
     
         6 . The variable valve system of  claim 1 , wherein the two lifts of the valve being realized by the two-step type variable valve lift apparatus are a high lift and a low lift, and the two-step type variable valve lift apparatus is configured to perform the high lift by supplying hydraulic pressure and to perform the low lift by releasing the hydraulic pressure. 
     
     
         7 . The variable valve system of  claim 1 , wherein the two lifts of the valve being realized by the two-step type variable valve lift apparatus are a high lift and a low lift, and the two-step type variable valve lift apparatus is configured to perform the low lift by supplying hydraulic pressure and to perform the high lift by releasing the hydraulic pressure. 
     
     
         8 . The variable valve system of  claim 1 , wherein the two-step type variable valve lift apparatus comprises:
 an outer body configured to selectively make a lever motion depending on rotation of the cam and configured such that the valve is connected with one end of the outer body, a rotation axis of the lever motion is disposed at an other end of the outer body, and an inside space is formed in the outer body;   an inner body disposed in the inside space of the outer body and adapted that one end of the inner body is rotatably connected with the one end of the outer body;   a connecting shaft disposed to penetrate the one end of the outer body and the one end of the inner body so as to connect the outer body with the inner body; and   a lost motion spring configured to return the inner body being relatively rotated with the outer body around the connecting shaft.   
     
     
         9 . The variable valve system of  claim 8 , wherein the inner body is configured to perform a lever motion together with the outer body depending on the rotation of the cam around the rotation axis of the lever motion of the outer body during being selectively fixed to the outer body, and the inner body is configured to perform a lever motion alone depending on the rotation of the cam around the connecting shaft during releasing from the outer body. 
     
     
         10 . The variable valve system of  claim 9 , wherein the two-step type variable valve lift apparatus is configured to perform a high lift of the valve as the outer body makes the lever motion together with the inner body, and configured to perform a low lift of the valve as only the inner body makes a lever motion around the connecting shaft. 
     
     
         11 . The variable valve system of  claim 8 , wherein the inner body forms an inside space and the two-step type variable valve lift apparatus further comprises a roller disposed in the inside space of the inner body and rotatably connected with the inner body so as to rolling-contact with the cam so that the inner body makes a lever motion depending on the rotation of the cam.