초록 ▼

The present invention provides a hydraulic actuator for operating an engine valve, which includes a means for controlling the seating velocity of the valve. The design allows for free, unrestricted movement of the actuator piston during opening of the engine valve, and an unrestricted return of the

The present invention provides a hydraulic actuator for operating an engine valve, which includes a means for controlling the seating velocity of the valve. The design allows for free, unrestricted movement of the actuator piston during opening of the engine valve, and an unrestricted return of the piston and valve until the valve is within a predetermined distance of the valve seat. Once within this predetermined range, the return velocity of the actuator piston and engine valve are limited by the rate at which a fluid may escape through a restriction. The restriction is calibrated to provide the desired maximum valve seating velocity. The invention also provides for automatic lash adjustment.

대표청구항 ▼

1. A hydraulic valve actuator for operating an engine valve comprising:an actuator housing; an actuator piston having upper and lower ends, wherein said piston is reciprocally disposed within said housing and is adapted to be moved upward and downward in response to hydraulic pressure; said lower en

1. A hydraulic valve actuator for operating an engine valve comprising:an actuator housing; an actuator piston having upper and lower ends, wherein said piston is reciprocally disposed within said housing and is adapted to be moved upward and downward in response to hydraulic pressure; said lower end of said actuator piston is operatively connected to the engine valve so that the engine valve opens when said actuator piston is displaced downward in response to hydraulic pressure upon said upper end, and when the hydraulic pressure is removed from said upper end said actuator piston returns upward and the engine valve shuts; a feed and drain passage in said housing to allow hydraulic fluid to move to and from said upper end of said actuator piston; and a control element disposed within said actuator housing, wherein said control element provides a restriction in hydraulic fluid flow during a portion of the return stroke of said actuator piston thereby limiting the velocity of the actuator piston, wherein said actuator piston includes longitudinal and transverse passages which allow fluid to move from said feed and drain passage to the upper end of said piston.