Variable valve actuator

Abstract

A variable valve actuator may include a rocker arm which may be pivotally connected to a rocker shaft, and of which a rocker arm hydraulic pressure supply line and a rocker arm hydraulic pressure exhaust line may be formed therein, a variable control piston which may be fluid-connected to the rocker arm hydraulic pressure supply line and slidably interferes the rocker arm hydraulic pressure exhaust line to selectively close the rocker arm hydraulic pressure exhaust line according to supplying hydraulic pressure of the rocker arm hydraulic pressure supply line, an actuating portion which may be selectively fluid-connected to the rocker arm hydraulic pressure supply line and the rocker arm hydraulic pressure exhaust line by the variable control piston such that the actuating portion selectively protrudes according to the supplying hydraulic pressure of the rocker arm hydraulic pressure supply line, and a valve unit opened according to reciprocation of the actuating portion.

What is claimed is: 
     
         1 . A variable valve actuator comprising:
 a rocker arm which is pivotally connected to a rocker shaft, and of which a rocker arm hydraulic pressure supply line and a rocker arm hydraulic pressure exhaust line are formed therein,   wherein an actuating portion comprises:
 a screw which is disposed at an end of the rocker arm, fluid-connected to the rocker arm hydraulic pressure supply line for being selectively supplied hydraulic pressure therefrom, and fluid-connected to the rocker arm hydraulic pressure exhaust line for exhausting the hydraulic pressure thereto; 
 an actuator piston which is slidably disposed within the screw and selectively moves up and down according to the hydraulic pressure supplied to the screw through the rocker arm hydraulic pressure supply line; 
 a check ball which is disposed between the rocker arm hydraulic pressure supply line and the rocker arm hydraulic pressure exhaust line for selectively supplying the hydraulic pressure from the rocker arm hydraulic pressure supply line into the actuator piston; and 
 an actuator spring elastically supporting the check ball toward the rocker arm hydraulic pressure supply line in the actuator piston; 
   wherein a variable control portion comprises:
 a variable control piston which is fluid-connected to the rocker arm hydraulic pressure supply line and slidably interferes the rocker arm hydraulic pressure exhaust line, and selectively closes the rocker arm hydraulic pressure exhaust line according to the hydraulic pressure of the rocker arm hydraulic pressure supply line supplied to an end thereof; and 
 a variable control spring elastically biasing the variable control piston to open the rocker arm hydraulic pressure exhaust line; and 
   wherein a valve unit is opened by the actuator piston in accordance with pivoting motion of the rocker arm.   
     
     
         2 . The variable valve actuator of  claim 1 , wherein the actuating portion further comprises:
 a return spring elastically biasing the actuator piston toward the rocker arm hydraulic pressure supply line; and   a first snap ring formed between the screw and the actuator piston for supporting the return spring not to be disconnected from the screw.   
     
     
         3 . The variable valve actuator of  claim 1 , wherein the actuating portion further comprises a socket ball assembly of which an opening portion is formed thereto for the actuator piston to be pivotally connected thereto. 
     
     
         4 . The variable valve actuator of  claim 3 , wherein the socket ball assembly comprises:
 a retainer of which the opening portion is formed at upper portion thereof and a cutting portion is formed at a lateral side thereof to slidably receive a piston lower portion of the actuator piston; and   a socket ball which is connected to the retainer and contacts the valve unit.   
     
     
         5 . The variable valve actuator of  claim 1 , wherein the variable control portion further comprises:
 a plate supporting the variable control spring at a lower portion thereof; and   a second snap ring supporting the plate.   
     
     
         6 . The variable valve actuator of  claim 1 , wherein the variable valve actuator further comprises a solenoid valve which controls supplying hydraulic pressure of the rocker arm hydraulic pressure supply line. 
     
     
         7 . The variable valve actuator of  claim 1 , wherein the variable valve actuator further comprises an actuating portion insert hole formed to the end of the rocker arm and a variable control portion insertion hole formed beside the actuating portion insert hole, and
 wherein the actuating portion is inserted into the actuating portion insert hole and the variable control portion is inserted into the variable control portion insertion hole.   
     
     
         8 . A variable valve actuator comprising:
 a rocker arm which is pivotally connected to a rocker shaft, and of which a rocker arm hydraulic pressure supply line and a rocker arm hydraulic pressure exhaust line are formed therein;   a variable control piston which is fluid-connected to the rocker arm hydraulic pressure supply line and slidably interferes the rocker arm hydraulic pressure exhaust line to selectively close the rocker arm hydraulic pressure exhaust line according to supplying hydraulic pressure of the rocker arm hydraulic pressure supply line;   an actuating portion which is selectively fluid-connected to the rocker arm hydraulic pressure supply line and the rocker arm hydraulic pressure exhaust line by the variable control piston such that the actuating portion selectively protrudes according to the supplying hydraulic pressure of the rocker arm hydraulic pressure supply line; and   a valve unit opened according to reciprocation of the actuating portion.   
     
     
         9 . The variable valve actuator of  claim 8 , wherein the variable valve actuator further comprises an actuating portion insert hole formed to an end of the rocker arm and a variable control portion insertion hole formed beside the actuating portion insert hole,
 wherein the actuating portion is inserted into the actuating portion insert hole and the variable control portion is inserted into the variable control portion insertion hole.   
     
     
         10 . The variable valve actuator of  claim 9 , wherein the actuating portion comprises:
 a screw connected to the actuating portion insert hole and being selectively supplied supplying hydraulic pressure from the rocker arm hydraulic pressure supply line;   an actuator piston which is slidably disposed within the screw and selectively moves up and down according to the supplying hydraulic pressure supplied to the screw from the rocker arm hydraulic pressure supply line;   a check ball which is disposed between the rocker arm hydraulic pressure supply line and the rocker arm hydraulic pressure exhaust line for selectively supplying the supplying hydraulic pressure from the rocker arm hydraulic pressure supply line into the actuator piston; and   an actuator spring elastically supporting the check ball toward the rocker arm hydraulic pressure supply line.   
     
     
         11 . The variable valve actuator of  claim 10 , wherein the actuating portion comprises:
 a return spring elastically supporting the actuator piston toward the rocker arm hydraulic pressure supply line; and   a first snap ring which is inserted between the screw and the actuator piston for preventing disconnection of the actuator piston and the return spring.   
     
     
         12 . The variable valve actuator of  claim 11 , wherein the actuating portion further comprises a socket ball assembly of which an opening portion is formed thereto for the actuator piston to be pivotally connected thereto. 
     
     
         13 . The variable valve actuator of  claim 12 , wherein the socket ball assembly comprises:
 a retainer of which the opening portion is formed at an upper portion thereof to receive a piston lower portion therein and a cutting portion is formed at a lateral side thereof; and   a socket ball which is connected to the retainer and slidably contacts the valve unit.   
     
     
         14 . The variable valve actuator of  claim 9 , wherein the variable control portion further comprises:
 a plate supporting the variable control spring to open the rocker arm hydraulic pressure exhaust line; and   a second snap ring supporting the plate.   
     
     
         15 . The variable valve actuator of  claim 8 , wherein the variable valve actuator further comprises a solenoid valve which controls the supplying hydraulic pressure of the rocker arm hydraulic pressure supply line.