CAM SHAFT AND MANUFACTURING METHOD FOR THE SAME

摘要

A cam shaft and a manufacturing method for the same are provided to improve durability by positioning a cam lobe closely to a cam journal as much as reduced thickness due to a thickness reducing part. A cam shaft comprises: a base part(72a) which does not operate an inlet valve; a cam lobe(72) having a lift part(72b) operating the inlet valve; a first receiving part(71a) receiving the reaction force from the base part; a second receiving part(71b) receiving the reaction force from the lift part; and a cam journal(71). The cam journal is positioned closely to the cam lobe. A thickness reducing part(71c) is formed at the first receiving part to make the axial width dimension of the first receiving part smaller than the axial width dimension of the second receiving part. The thickness reducing part(72c) is formed at the base part to make the axial width dimension of the base circle part smaller than the axial width dimension of the lift part.