Injection molded shaft

An injection molded shaft comprising:

• a first torque applied part formed at a first end in an axial direction;
• a second torque applied part formed at a second end in the axial direction;
• and
• a shaft body connecting the first torque applied part to the second torque applied part along a direction of a longitudinal center axis,
• wherein the first torque applied part, the second torque applied part, and the shaft body are integrally formed of resin material to have a unitary one-piece construction,
• wherein the shaft body includes:
• a first connecting part formed integrally with the first torque applied part,
• a second connecting part formed integrally with the second torque applied part,
• a core part extending from the first connecting part to the second connecting part along the longitudinal center axis, the core part having a crisscross cross section orthogonal to the axial direction,
• a plurality of first framework parts formed at regular intervals along the direction of the longitudinal center axis in the core part between the first connecting part and the second connecting part, each of the first framework parts having a discoid cross section orthogonal to the axial direction,
• a second framework part disposed in a portion partitioned by the first connecting part, the first framework part adjacent to the first connecting part;
• and the core part, the second framework part being a diagonal brace extending across the first connecting part, the first framework part, and the core part,
• a third framework part disposed in a portion partitioned by a pair of the first framework parts adjacent to each other and the core part, the third framework part being a diagonal brace extending across the pair of first framework parts and the core part, and
• a fourth framework part disposed in a portion partitioned by the second connecting part, the first framework part adjacent to the second connecting part and the core part, the fourth framework part being a diagonal brace extending across the second connecting part, the first framework part, and the core part.