Cam sprocket and method for manufacturing the same

A cam sprocket made of a stamped component that is attachable to one end in axial direction of a cam shaft of an engine, comprising:

• a ring-shaped plate portion that extends in a radial direction at a radially outer region of the cam sprocket by letting a radially inner region of the cam sprocket jut out in one axial direction, and that is provided with external teeth along its outer circumference;
• a circular plate portion that is disposed at the radially inner region substantially parallel to the ring-shaped plate portion and at a level difference in axial direction to the ring-shaped plate portion, the circular plate portion being abuttable against one end face in axial direction of the cam shaft;
• and
• a tapered portion linking the circular plate portion to the ring-shaped portion at a radially intermediate region;
• wherein the tapered portion and the circular plate portion is provided with a plurality of punched portions for abutting the circular plate portion against the one face in axial direction of the cam shaft after matching a center of curvature of a circle circumscribing the external teeth to a rotation axis of the cam shaft when attaching the cam sprocket to the one end in axial direction of the cam shaft;
• and
• wherein the plurality of punched portions are formed by punching at several locations along the circumferential direction in a direction that is opposite to the direction in which the circular plate portion juts out, and radially inner faces of the punched portions are provided with a partial circular arc shape so as to come into area contact with an outer circumferential surface at the one end in axial direction of the cam shaft.