Camshaft and assembling method thereof

An assembling type of camshaft comprising

• a plurality of cam pieces each of which has a shaft hole, and
• a shaft to be press-fitted into the shaft holes of the plurality of cam pieces,
• wherein
• a press-fitting groove and a penetration groove are respectively formed to extend in an axial direction in an inside circumferential surface of the shaft hole of each cam piece,
• a plurality of press-fitting-tooth parts is formed at regular or odd intervals in the axial direction in an outside circumferential surface of the shaft, each of the plurality of press-fitting-tooth parts having a press-fitting tooth extending partially in the axial direction, and
• the press-fitting tooth is adapted to be press-fitted into the press-fitting groove in the axial direction and to pass through the penetration groove in the axial direction.

An assembling method of an assembling type of camshaft including:

• a plurality of cam pieces each of which has a shaft hole, and
• a shaft to be press-fitted into the shaft holes of the plurality of cam pieces,
• wherein
• a press-fitting groove and a penetration groove are respectively formed to extend in an axial direction in an inside circumferential surface of the shaft hole of each cam piece,
• a plurality of press-fitting-tooth parts is formed at regular or odd intervals in the axial direction in an outside circumferential surface of the shaft, each of the plurality of press-fitting-tooth parts having a press-fitting tooth extending partially in the axial direction, and
• the press-fitting tooth is adapted to be press-fitted into the press-fitting groove in the axial direction and to pass through the penetration groove in the axial direction,
• the assembling method comprising:
• a step of locating each cam piece at a predetermined position by causing each cam piece to pass over one or more portions of the shaft wherein no press-fitting-tooth part is formed, if necessary, and by causing each cam piece to pass through one or more press-fitting-tooth parts of the shaft by using the penetration groove of each cam piece, if necessary,
• a step of adjusting a phase of each cam piece to the shaft by rotating each come piece at the predetermined position, and
• a step of press-fitting each cam piece to the press-fitting tooth of a press-fitting-tooth part of the shaft by using the press-fitting groove of each cam piece.

A cam piece having a shaft hole to be press-fitted to a shaft, wherein

• a plurality of press-fitting grooves is formed at regular intervals in a circumferential direction of an inside circumferential surface of the shaft hole, each of the plurality of press-fitting grooves extending in an axial direction, the number of the plurality of press-fitting grooves being a multiple of twelve,
• a plurality of penetration grooves is formed at regular intervals in the circumferential direction of the inside circumferential surface of the shaft hole correspondingly to an arrangement of the plurality of press-fitting grooves, each of the plurality of penetration grooves extending in the axial direction, the number of the plurality of penetration grooves being a multiple of twelve,
• the plurality of press-fitting grooves are adapted to be press-fitted together in the axial direction to a plurality of press-fitting teeth formed on an outside circumferential surface of the shaft correspondingly to an arrangement of the plurality of press-fitting grooves, and
• the plurality of penetration grooves are adapted to pass through the plurality of press-fitting teeth together in the axial direction.