| 摘要 |
PROBLEM TO BE SOLVED: To open the safety valve in a more ideal condition for both pressure and temperature, and to open the safety valve by a precise pressure by utilizing effectively the magnetic force by decreasing drastically the leakage of magnetism to the outside. SOLUTION: The battery is equipped with a safety valve 3 which opens when the internal pressure of the battery becomes higher than the specified pressure. The safety valve 3 comprises an elastic body 4 and a permanent magnet 5 that are housed in a cover case 8 and a valve hole plate 6 having a valve hole 6A that is opened and shut by the elasticity of the elastic body 4 and the magnetic suction force of the permanent magnet 5. The valve hole plate 6 and the cover case 8 are constructed of a ferromagnetic material respectively and the magnetic flux of the permanent magnet 5 loops the closed magnetic circuit by the cover case 8 and the valve hole plate 6. Further, the permanent magnet 5 has thermo-demagnetizing characteristics in which the force of opening and shutting the valve hole 6A decreases as the temperature rises.
|
