High-pressure tank having sealing boss and manufacturing method thereof

A high-pressure tank comprising:

• a boss portion having a skirt extending radially outward, the skirt having a plurality connection holes;
• a tank body of which an upper portion is overlapped by the skirt of the boss portion so that the tank body is coupled with the boss portion;
• and
• a sealing portion disposed between the skirt and the upper portion of the tank body,
• wherein the skirt comprises a plurality of fastening grooves respectively coupled with keys of a dome portion of a lower portion of the tank body, each of the plurality of fastening grooves having a narrow entrance and an enlarged inner space, forming a T-shape,
• wherein the skirt has a first stepped portion and a second stepped portion, the first stepped portion, which is recessed, is formed at an outer peripheral surface of the skirt, and the second stepped portion is formed at an inner peripheral surface of the skirt,
• wherein the second stepped portion provides a horizontal depth consistent along the inner peripheral surface of the skirt in a vertical direction, and allows a portion of one end of the dome portion to be correspondingly formed on the second stepped portion to a horizontal thickness corresponding to the horizontal depth along the inner peripheral surface,
• wherein the dome portion is coupled with the first stepped portion and the second stepped portion,
• wherein one end of the dome portion coupled with the second stepped portion is in contact with a port of the high-pressure tank,
• wherein the boss portion and the dome portion are connected to each other via the sealing portion without using threads or an O-ring, and
• wherein the plurality of fastening grooves are symmetrical with each other with respect to a center of the boss portion, and the plurality of fastening grooves are spaced apart from each other in a circumferential direction of the skirt.

A high-pressure tank comprising:

• a boss portion having a skirt extending radially outward formed at one end of the boss portion, the skirt having a plurality of connection holes formed along an outer periphery of the skirt;
• a sealing portion formed on an outer surface of the skirt;
• a dome portion coupled with the sealing portion;
• and
• a liner portion coupled with the dome portion,
• wherein the skirt comprises a plurality of fastening grooves respectively coupled with keys of the dome portion, each of the plurality of fastening grooves having a narrow entrance and an enlarged inner space, forming a T-shape,
• wherein the skirt has a first stepped portion and a second stepped portion, the first stepped portion, which is recessed, is formed at an outer peripheral surface of the skirt, and the second stepped portion is formed at an inner peripheral surface of the skirt,
• wherein the second stepped portion provides a horizontal depth consistent along the inner peripheral surface of the skirt in a vertical direction, and allows a portion of the one end of the dome portion to be correspondingly formed on the second stepped portion to a horizontal thickness corresponding to the horizontal depth along the inner peripheral surface,
• wherein the dome portion is coupled with the first stepped portion and the second stepped portion,
• wherein the boss portion comprises a central through-hole which forms a port of the high-pressure tank through which the dome portion is configured to flow out a fluid contained therein,
• wherein the plurality of fastening grooves are symmetrical with each other with respect to a center of the boss portion, and the plurality of fastening grooves are spaced apart from each other in a circumferential direction of the skirt.