VARIABLE VALVE TIMING APPARATUS

摘要

The present invention relates to a variable valve timing apparatus capable of adjusting the opening and shutting timing of air suction and exhaust valves in an engine and, more particularly, to a variable valve timing apparatus comprising: an actuator housing; an upper plunger embedded in the upper part of the actuator housing to be able to be lifted; a lower plunger embedded in the lower part of the actuator housing to lift the upper plunger; an oil chamber provided inside the actuator housing, and in which oil is circulated in response to the lifting operation of the upper plunger; and a communication flow path portion provided inside the actuator housing, and adjusting the communication flow of oil so as to control the falling speed of the upper plunger in response to the lifting operation of the lower plunger. Thus, the variable valve timing apparatus can adjust the opening and shutting timing of the air suction and exhaust valves by adjusting the lifting speed of the upper plunger using the circulatory flow of oil.