| 摘要 |
PURPOSE:To increase reliability of a safety valve by forming a safety valve of sealed lead-acid battery in such a way that a synthetic rubber plate is brought into contact with the outer surface of an exhaust hole and a sponge having continuous bubbles made of synthetic resin is pressed against the rubber plate. CONSTITUTION:A sealed lead-acid battery is formed so that oxygen gas evolved from a positive plate during charge is absorbed in a negative plate. A safety valve is formed in such a way that a shallow recess is installed in a cover 3 and an exhaust hole 4 is installed in its bottom, and a synthetic rubber plate 5 is brought into contact with the exhaust hole to close it, then a sponge having continuous bubbles comprising synthetic resin or synthetic rubber is pressed against the rubber plate 5. By setting compressibility of the sponge 6 in a specified value, gas is exhausted from the exhaust hole 4 when gas pressure in the cell increases in a designed value. Therefore, operation is stabilized and the battery is made compact. |
