Variable valve timing apparatus

摘要

A variable valve timing apparatus including: an actuator housing having a space at the inside thereof; an upper plunger mounted inside the upper portion of the actuator housing to move upward and downward; a lower plunger mounted inside the lower portion of the actuator housing to allow the upper plunger to move upward and downward; an oil chamber allows oil to be circulated upwardly and downwardly or blocks the flow of oil through a head formed on the top end periphery of the upper plunger in accordance with the upward and downward movements of the upper plunger; and a communicating passage allows the upper and lower end portions of the oil chamber to communicate with each other in accordance with upward and downward movements of the lower plunger and to adjust the oil flowing thereon to control the speeds of the upward and downward movements of the upper plunger.

主权项

1. A variable valve timing apparatus comprising:
an actuator housing having a given space portion at an inside thereof; an upper plunger insertedly mounted inside an upper portion of the actuator housing in such a manner as to move upward and downward; a lower plunger insertedly mounted inside a lower portion of the actuator housing in such a manner as to allow the upper plunger to move upward and downward; an oil chamber formed to allow oil to be circulated upwardly and downwardly or to allow the flow of oil to be blocked through a head formed on a top end periphery of the upper plunger in accordance with the upward and downward movements of the upper plunger; and a communicating passage portion adapted to allow the upper and lower end portions of the oil chamber to communicate with each other in accordance with the upward and downward movements of the lower plunger and to adjust the flow of oil flowing thereon to control the speeds of the upward and downward movements of the upper plunger, wherein the oil chamber comprises:
an upper chamber formed on the upper side portion of the upper plunger;a damping chamber formed on an outer peripheral surface of a body of the upper plunger in such a manner as to communicate with the lower side portion of the upper chamber or to be blocked therefrom in accordance with the upward and downward movements of the upper plunger; anda circulating passage adapted to allow the upper chamber and the damping chamber to communicate with each other and having an opening and closing valve mounted thereon to restrict oil movement.