Admission cam shaft of engine

The invention provides an admission cam shaft of an engine. According to the design range of the base circle radius in a molded line, the base circle radius of the cam shaft is 16 mm, the maximum lift range of the cam molded line is 8 mm, and the lift range of the buffer section of a cam is 0.29 mm. From one end of the cam shaft to the other end of the cam shaft, the opening angle between the radial center of the cam shaft and the buffer section is 3.5 degrees, the opening buffer section angle between the opening end point and the buffer section is 27.5 degrees, the valve opening section angle between the point where the valve gap is completely eliminated and the valve closing point is 59 degrees, the closing buffer section angle between the valve closing point and the closing buffer section ending point is 27.5 degrees, and the ending angle between the closing buffer section ending point and the closing end point is 3.5 degrees. The symmetrical molded line design is adopted for the opening side and the closing side of the cam type axis and the opening buffer section and the closing buffer section, the maximum acceleration of the cam can reach 0.029 mm/deg<2>, the low-rotating-speed torque of the engine is increased, the power performance of the engine is improved, and emission of harmful gas is reduced.