Cylinder deactivation system for vehicle and variable valve lift system using the same

A cylinder deactivation system for a vehicle, comprising:

• a rocker shaft having an oil supply hole;
• a rocker arm, of which the rear portion is hinge-connected with the rocker shaft so that the front portion thereof drives a valve;
• a middle arm, in which a bearing is mounted in the front portion thereof to rolling-contact with a cam and the rear end thereof is hinge-connected with the rocker shaft;
• and
• a latching portion separating the rocker arm from the middle arm when an oil pressure operates through the oil supply hole;
• wherein the latching portion comprises:
• a spring support portion inserted into the bottom of the bearing mounted in the front end of the middle arm and including a projection projected forward;
• a return spring penetrated and supported by the projection;
• and
• a latching pin, of which the rear portion is supported elastically by the return spring and the front portion is curved from both ends of the rear portion in the forward direction.