Variable valve lift apparatus

摘要

A variable valve lift apparatus for changing a lift of an intake or exhaust valve in at least two stages may include a lever body, a piston, a cylinder, a hydraulic pressure chamber, an active portion, a hinge portion, a roller, a rotation shaft, a guide slot, a hydraulic pressure supply portion, and an elastic member, in which the lever body may make a lever motion at an end with the intake valve or the exhaust valve connected thereto, the piston may make reciprocal motion in the cylinder, the rotation shaft may pass through the hinge portion and the roller and be a rotation center of the roller, moving together with the roller, the hydraulic pressure supply portion may supply hydraulic pressure to the hydraulic pressure chamber for moving the piston, and the elastic member may return the piston if the hydraulic pressure being supplied to the hydraulic pressure chamber is removed.

主权项

1. A variable valve lift apparatus for changing a lift of an intake or an exhaust valve in at least two stages comprising:
a lever body having a fixed length for making a lever motion according to rotation of a cam, wherein a first end of the lever body includes the intake valve or the exhaust valve connected to the first end of the lever body; a piston slidably mounted in the lever body and making reciprocal motion in a length direction of the lever body; a cylinder fixedly-mounted to the lever body to slidably receive the piston therein for the piston to make the reciprocal motion within the cylinder; a hydraulic pressure chamber formed in the cylinder between an inside surface of the cylinder and the piston; an active portion slidably provided in the lever body and connected to the piston to reciprocate together with the piston; a hinge portion slidably arranged in the lever body and hingedly connected to the active portion; a roller rotatably connected to the hinge portion and selectively movable in the length direction of the lever body by the reciprocal motion of the piston; a rotation shaft provided to pass through the lever body, the hinge portion and the roller for being a rotation center of the roller and moving together with the roller; a guide slot formed in the lever body, wherein the rotation shaft is slidably mounted in the guide slot for guiding a movement of the rotation shaft; a hydraulic pressure supply portion selectively supplying hydraulic pressure to the hydraulic pressure chamber for moving the piston in a second end direction of the lever body; and an elastic member arranged in the lever body and elastically biasing the active portion toward a first end direction of the lever body for returning the piston to an original position when the hydraulic pressure being supplied to the hydraulic pressure chamber is removed.