Overhead type relief pressure valve cam mechanism

The utility model relates to an overhead type relief pressure valve cam mechanism, including camshaft and deceleration valve, the below of camshaft is provided with and is used for driving the valve tappet that the exhaust valve was opened and close, valve tappet can be for the camshaft elevating movement, the relief pressure valve is shaft-likely, the axial of relief pressure valve is parallel to each other with the axial of camshaft, the relief pressure valve is provided with the centrifugation piece in the one side that is close to the camshaft terminal surface, the one end of centrifugation piece and the tip fixed connection of relief pressure valve can need reduce the engine start jar according to the operating mode effectively and press, make the electricity of engine, foot start-up reliability increase to the integral design of relief pressure valve, promptly: the relief pressure valve connects firmly into a whole with the centrifugation piece, has not only improved the intensity of relief pressure valve, has the connecting piece simultaneously still less, beneficial effect such as compact structure.