High-pressure tank liner, high-pressure tank liner manufacturing method and high-pressure tank

A high-pressure tank liner manufacturing method comprising the steps of:

• joining flanges of a pair of liner half bodies to each other, each liner half body including a body portion formed from a cylindrical body, and the flange formed at an opening on one end side of the body portion;
• forming a diameter-expanded part of a cylindrical body with a larger diameter than an outside diameter of a general part of the body portion by cutting a joint portion between the flanges of the liner half bodies in a circumferential direction of the cylindrical body;
• and
• forming a staircase portion including stairs by cutting a stepped portion formed between the general part and the diameter-expanded part of the body portion, wherein
• the stepped portion is cut in the step of forming a staircase portion such that a distance from a corner on the diameter-expanded part side of the stepped portion to a peripheral surface of the general part while passing through a corner of each stair constituting the staircase portion is shorter than a lateral width of roving formed from reinforced fibers arranged in such a way as to extend in a circumferential direction of the body portion.

A high-pressure tank comprising:

• a high-pressure tank liner including
• a body portion formed from a cylindrical body,
• a diameter-expanded part formed into a cylindrical body at the body portion with a larger diameter than an outside diameter of a general part of the body portion, and
• a staircase portion including stairs and formed at a stepped portion between the general part and the diameter-expanded part of the body portion;
• and
• a fiber-reinforced resin layer provided in such a way as to cover an outer side of the high-pressure tank liner, wherein
• reinforced-fiber roving constituting the fiber-reinforced resin layer is disposed in such a way as to be wound around an outer peripheral surface of the high-pressure tank liner around an axis of the high-pressure tank liner, and
• the roving has a width larger than a distance in the high-pressure tank liner from a corner on the diameter-expanded part side of the stepped portion to a peripheral surface of the general part while passing through a corner of each stair constituting the staircase portion.