| 摘要 |
PURPOSE: To enhance safety of a battery without hindering an explosion-proof function of a thin part by arranging injection gates on a boss part end surface close to the thin part. CONSTITUTION: A sealing body 1 molded by metal molds M is provided with a cylindrical boss part 4 having a hole 3 to press in a current collecting shaft, a cylindrical outer wall part 5 to press in a battery case and a disk-shaped connecting part 9 to connect the boss part 4 and the outer wall part 5 to each other. A joining part with the boss part 4 of the connecting part 9 is formed as an annular thin part 2. Gates 7 of the metal molds M are branched off into two parts, and are connected to an end surface of the boss part 4. A distance up to the thin part 2 from the gates 7 is not more than a half of an axial directional length of the boss part 4, and melting resin injected from the gates 7 is filled in the annular thin part 2 in an excellently fluid condition. The gates 7 are positioned inside slightly leaving a space more than the inner peripheral edge and the outer peripheral edge of an end surface of the boss part 4, and corners of the inner and outer peripheral edges of the boss part 4 are left as they are. |
