Spline member manufacturing apparatus and manufacturing method

A spline member manufacturing apparatus that manufactures a spline member having a spline portion including ridge portions that are formed along an axial direction on an inner circumferential surface of a boss portion and groove portions that are formed between the ridge portions so that the ridge portions and the groove portions alternate, by using a material including a plate-like base plate portion and the boss portion that is in a shape of a circular tube and is provided so as to project from a first surface that is one of surfaces of the base plate portion, the spline member manufacturing apparatus comprising:

• a shaving punch and a shaving die that are used for forming a cutout portion in at least a part of an outer circumference portion of the base plate portion;
• a spline punch that is inserted along the inner circumferential surface of the boss portion and is used for forming the spline portion;
• and
• a stripper that supports the first surface of the base plate portion and an outer circumferential surface of the boss portion, wherein
• the shaving punch, the shaving die, the spline punch, and the stripper are positioned coaxially, while the stripper is positioned on an outer circumference side of the spline punch, whereas the shaving die is positioned on an outer circumference side of the stripper, and the shaving punch is positioned so as to be opposite to the stripper in the axial direction, the shaving punch being provided so as to be movable in the axial direction relative to the shaving die and the spline punch, and the stripper being provided so as to make a relative retreating movement due to a pressing force of the shaving punch,
• the stripper supports the first surface of the base plate portion and the outer circumferential surface of the boss portion,
• the shaving punch is relatively advanced toward the stripper and contacts a second surface of the base plate portion, the second surface being a surface on an opposite side of the first surface, and the shaving punch is further advanced relatively, while the material and the stripper are being pressed, and a shearing force is applied to the material by the shaving punch and the shaving die, so that the cutout portion is formed in at least a part of the outer circumference portion of the base plate portion, and
• after the cutout portion is formed in at least the part of the outer circumference portion of the base plate portion, the shaving punch is further advanced relatively, while an outer circumferential surface of the base plate portion is held by the shaving die, so that the spline portion is formed by inserting the spline punch along the inner circumferential surface of the boss portion.