Abstract: A high-pressure vessel includes: a body portion formed in a cylindrical shape, with at least one end portion of the body portion, in an axial direction thereof, being open; a cap, at least part of which is inserted inside at least one open end portion of the body portion to plug the at least one open end portion; a first reinforcement layer provided on an outer peripheral surface of the body portion and made of fiber-reinforced plastic, a fiber direction of which coincides with a circumferential direction of the body portion; and a second reinforcement layer integrated with the first reinforcement layer and made of fiber-reinforced plastic including fibers that bridge one end portion and another end portion, in the axial direction, of the body portion.

Abstract: A high-pressure vessel includes: a body portion formed in an open cylindrical shape; a cap, at least a part of the cap being inserted inside an opening of at least one end portion of the body portion to thereby plug the end portion; a first reinforcement layer provided at an outer peripheral surface of the body portion and configured by fiber-reinforced plastic having a fiber direction that coincides with a circumferential direction of the body portion; and a second reinforcement layer configured by fiber-reinforced plastic including fibers that pass through a center portion of the cap, as seen in the axial direction of the body portion, and that are disposed parallel to the axial direction of the body portion, as seen in a direction orthogonal to the axial direction of the body portion.

Abstract: A joining-member welding unit includes a first member made of metal, a second member overlapped with one surface of the first member, a joining member made of the same kind of metal as the first member, and a welder. The second member has a through-hole defined by an inner wall surface thereof. The inner wall surface and the one surface define a recessed portion. The joining member includes a large-diameter plate portion having an outer diameter larger than a diameter of the through-hole and a thickness smaller than the diameter of the through-hole, and a protruding portion protruding from the large-diameter plate portion and to be inserted into the through-hole. The welder includes a holding portion that holds the joining member. The welder applies an electric current to the joining member to melt the protruding portion such that the first member and the second member are joined together.

Abstract: A high-pressure vessel includes: a body portion formed in a cylindrical shape, with at least one end portion of the body portion, in an axial direction thereof, being open; a cap, at least part of which is inserted inside at least one open end portion of the body portion to plug the at least one open end portion; a first reinforcement layer provided on an outer peripheral surface of the body portion and made of fiber-reinforced plastic, a fiber direction of which coincides with a circumferential direction of the body portion; and a second reinforcement layer integrated with the first reinforcement layer and made of fiber-reinforced plastic including fibers that bridge one end portion and another end portion, in the axial direction, of the body portion.

Abstract: A high-pressure vessel includes: a body portion formed in an open cylindrical shape; a cap, at least a part of the cap being inserted inside an opening of at least one end portion of the body portion to thereby plug the end portion; a first reinforcement layer provided at an outer peripheral surface of the body portion and configured by fiber-reinforced plastic having a fiber direction that coincides with a circumferential direction of the body portion; and a second reinforcement layer configured by fiber-reinforced plastic including fibers that pass through a center portion of the cap, as seen in the axial direction of the body portion, and that are disposed parallel to the axial direction of the body portion, as seen in a direction orthogonal to the axial direction of the body portion.