Valve driving apparatus

Abstract

Disclosed herein is a valve driving apparatus. The valve driving apparatus includes at least one swing arm having one side corresponding to an upper side of a valve opening and closing a combustion chamber of an internal combustion engine; and a cam unit periodically pivoting the swing arm. Here, the swing arm performs a swing motion on the other side thereof by external manipulation to periodically compress the valve. The valve driving apparatus is capable of adjusting lift amounts of valves opening and closing a combustion chamber of an internal combustion engine.

1 . A valve driving apparatus, comprising:
 at least one swing arm having one side corresponding to an upper side of a valve opening and closing a combustion chamber of an internal combustion engine, the swing atm performing a swing motion on the other side thereof by external manipulation to periodically compress the valve; and   a cam unit periodically pivoting the swing aim.   
   
   
       2 . The valve driving apparatus according to  claim 1 , wherein the cam unit comprises:
 a pivot member acting as a reference axis of the cam unit;   a web member formed on the pivot member;   a high rotary shaft forcibly rotated by an external force;   a high lift cam formed on the high rotary shaft and including a high eccentric rod eccentrically rotated during rotation of the high rotary shaft; and   a sub-cam unit connected to the web member and simultaneously operating the at least one swing arm through the high eccentric rod during rotation of the high lift cam.   
   
   
       3 . The valve driving apparatus according to  claim 2 , wherein the sub-cam unit comprises:
 a low rotary shaft rotatably connected to the web member;   a cam body formed on the low rotary shaft;   a follow arm formed on the cam body to be rotated in a direction of the swing arm by periodic compression of the high eccentric rod;   a low lift cam formed on the low rotary shaft and including a low eccentric rod to periodically compress one side of the corresponding swing arm at the same time during rotation of the follow arm; and   an elastic member elastically supporting the cam body.   
   
   
       4 . The valve driving apparatus according to  claim 3 , wherein the cam body comprises the same number of low lift cams at opposite sides of the follow arm. 
   
   
       5 . The valve driving apparatus according to  claim 3 , wherein the follow arm is provided with a rotatable follow roller at a portion thereof where the follower arm directly contacts the high lift cam. 
   
   
       6 . The valve driving apparatus according to  claim 3 , wherein the low lift cam comprises a contact surface formed to support a center of the swing arm. 
   
   
       7 . The valve driving apparatus according to  claim 6 , wherein the swing arm comprises a rotatable swing roller disposed at a portion thereof contacting the contact surface. 
   
   
       8 . The valve driving apparatus according to  claim 3 , wherein the follow arm and the low lift cam are extended from the cam body in different directions from each other. 
   
   
       9 . The valve driving apparatus according to any one of  claims 2  to  8 , wherein the web member is rotatably connected to the link shaft, and the link shaft is connected to an actuation unit, the actuation unit adjusting a compression amount of the low lift cam on the one side of the swing arm depending on a slanted degree of the follow arm that varies according to movement of the link shaft along an arcuate track about the pivot member. 
   
   
       10 . The valve driving apparatus according to  claim 9 , wherein the actuation unit comprises:
 a connecting rod connected to the link shaft;   a link pin linked to the connecting rod;   a screw member linked to the link pin and linearly reciprocating in a perpendicular direction to an axis of the link shaft to reciprocate the link shaft on the arcuate track; and   a power transmission member formed around a circumference of the screw member and reciprocating the screw member in a forward and rearward direction when the power transmission member is forcibly rotated by an external force.   
   
   
       11 . The valve driving apparatus according to  claim 9 , wherein the actuation unit comprises:
 an actuator having a receiving groove that receives the link shaft therein; and   a screw member screwed to the actuator and linearly reciprocating the actuator in a forward and rearward direction to guide reciprocation of the link shaft on an arcuate track when the screw member is forcibly rotated by an external force.   
   
   
       12 . The valve driving apparatus according to  claim 9 , wherein the elastic member is supported at one side thereof by the link shaft and at the other side thereof by the cam body. 
   
   
       13 . The valve driving apparatus according to  claim 9 , wherein the sub-cam unit is received in a housing, and wherein the sub-cam unit and the housing comprise oil passages connected to each other between the sub-cam unit and the housing to receive a lubricant from outside through the oil passages.