Sealing arrangement of a battery filling port using a rivet

A sealed battery comprising:

• a battery case comprising a cover portion with an open through-hole;
• a plug member that plugs the through-hole;
• and
• a seal member that is an elastic body that seals between the through-hole and the plug member, wherein
• the plug member is a blind rivet that includes a flange formed with a diameter larger than a diameter of the through-hole, and a sleeve formed with a diameter smaller than the diameter of the through-hole;
• a tapered surface that is inclined toward an inside of the battery case is formed on a peripheral portion of the through-hole of an outside surface of the battery case, the tapered surface being inclined at the same angle throughout the tapered surface from a level portion of the cover portion to an inner wall surface of the through-hole, the inner wall surface extending parallel to the axial direction of the through-hole;
• and
• the seal member is sandwiched between the flange and the tapered surface, and the through-hole is sealed by the flange, by a portion of the sleeve that is inserted into the inside of the battery case being plastic deformed so as to bulge out.