High-pressure tank and method for manufacturing high-pressure tank

A method for manufacturing a high-pressure tank, comprising:

• an assembly providing step of providing an assembly including a cap that is fixed to a dome portion of a liner made of resin wherein the cap has a flange portion overlapping the dome portion of the liner, the liner has a cylindrical trunk and the dome portion at an end of the trunk, and the cap is formed with a supply and discharge hole configured to supply and discharge fluid to and from the liner, and a protective member having a sheet shape extends over the cap and the liner;
• and
• a reinforcing layer forming step of forming a reinforcing layer including a plurality of fiber layers by winding fiber a plurality of times around an outer surface of the liner of the assembly,
• wherein:
• the dome portion is provided with an annular concave portion dented toward another end of the trunk,
• the flange portion of the cap is inserted in the annular concave portion,
• the protective member having the sheet shape is extended over the cap and the liner,
• in the reinforcing layer forming step, a starting end as a start of winding of the fiber is disposed overlapping the flange portion of the cap when viewed along an axial direction of the liner, and the flange portion is disposed between the annular concave portion and the reinforcing layer,
• the start of winding of the fiber is out of contact with the liner by the flange portion and the protective member interposed between the start of winding of the fiber and the liner,
• the start of winding of the fiber is disposed on the protective member,
• the protective member is not interposed between the flange portion and the liner,
• an outer circumferential end of the flange portion is in direct contact with the liner,
• the protective member extends over the liner radially outwardly beyond a position where the outer circumferential end of the flange portion is in direct contact with the liner,
• the liner is further provided with a cylindrical convex portion protruding outward in the axial direction of the liner from a central portion of the annular concave portion, and
• the protective member is formed in an annular shape surrounding the cylindrical convex portion.