Patent ID: 9181827
Filing Date: 2015-11-10
Classification: F01L

Abstract:
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.