Fiber-reinforced resin cylinder, manufacturing method for fiber-reinforced resin cylinder, and fiber-reinforced resin cylinder manufacturing jig

A method for manufacturing a fiber-reinforced resin cylinder comprising the steps of:

• fitting a second columnar portion of a first mandrel and a part of a cylindrical elastic member to each other, the first mandrel having a first columnar portion and the second columnar portion which extends from an end portion of the first columnar portion in an axial direction and has a diameter smaller than that of the first columnar portion;
• fitting the elastic member and a metal cylinder member to each other such that the metal cylinder member is located on an outer side in a radial direction;
• fitting another part of the elastic member and a columnar second mandrel to each other;
• forming a fiber-reinforced resin cylinder member on outer peripheral surfaces of the first mandrel and the metal cylinder member;
• and
• separating the first mandrel, the elastic member, and the second mandrel from the fiber-reinforced resin cylinder member and the metal cylinder member.

A fiber-reinforced resin cylinder manufacturing jig comprising:

• a first mandrel which includes
• a first columnar portion having an outer peripheral surface on which a fiber is disposed, and
• a second columnar portion extending from an end portion of the first columnar portion in an axial direction and having a diameter smaller than that of the first columnar portion;
• a second mandrel which is disposed coaxially with the second columnar portion and has a third columnar portion extending in a direction separating from the first columnar portion;
• and
• a cylindrical elastic member which is fitted to the second columnar portion and the third columnar portion and has an outer diameter larger than an outer diameter of the first columnar portion.