| 摘要 |
PROBLEM TO BE SOLVED: To give an explosion-proof valve 21 of a battery pack a function as a vent hole to eliminate a need for separately providing an air vent having a ventilation film.SOLUTION: An explosion-proof valve 21 comprises: an explosion-proof valve case 22 formed of a synthetic resin, and forming an annular ring shape; an O-ring 23 sealing between this explosion-proof valve case 22 and a pack case; a circular sheet-like ventilation film 24 attached to the case 22 so as to close a central opening 22a of the explosion-proof valve case 22; and a circular plate-like protector 25 formed of a synthetic resin, and overlapped and arranged outside this ventilation film 24. Notches 61 as vent holes are provided around the protector 25, and a small amount of air can go in and out via the ventilation film 24. When an internal pressure rapidly rises at battery abnormality, the protector 25 is folded, and locking by locking projections 52 is released to drop the protector 25, and therefore, a large passage cross sectional area is secured instantaneously to release the internal pressure. |
