【考案の詳細な説明】[Detailed explanation of the idea]
本考案は、小形密閉式鉛蓄電池の改良に関する
ものである。
従来鉛蓄電池には充電時に水素ガス及び酸素ガ
スを発生する性質があり、陰極板に酸素ガスを吸
収させて密閉化を行なう方式においては、充電中
に陰極板での酸素ガス吸収能力を上回る酸素ガス
が発生した場合、排気口を経て排気筒と弁体との
間隙を通つて電池外部に放出される。
ところが第１図に示す如き、電解液注入口と排
気口を兼ねた形状の排気筒１および上端開口が閉
じられた筒状の弁体２′を有する電池においては、
電池が開路状態にある場合、電池内の酸素は陰極
板３に吸収され、電池内部は減圧状態となる。こ
の時の弁体２′は第２図に示す如き形状となり、
排気筒１と弁体２′の間隙部から、新たに外部空
気が電池内に流入し、該空気中の酸素が陰極板３
に吸収され、さらに硫酸との反応により陰極板３
は硫酸鉛化する。このように酸素の吸収（陰極板
の硫酸鉛化）→減圧状態（弁体２′の変形）→外
部空気の流入というサイクルが、電池内が酸素以
外の成分で常圧となるまで繰り返えされ、陰極板
３の容量が低下するという欠点を有していた。
本考案は、上記の如き欠点を除去するもので、
開路状態での放置による陰極板の容量が低下する
ことのない鉛蓄電池を提供することにある。
上記の目的を達成するために、本考案は、弁体
の下端縁部を外側に突出させてその肉厚を厚くす
ることにより、鉛蓄電池内が減圧状態になつた時
の外部空気の流入を防止せしめ陰極板の容量低下
を防がんとするものである。
次の本考案について説明する。
下端縁部４においてこの部分を外側に突出させ
てその肉厚を厚くならしめた第３図に示すような
形状の弁体２を蓋５の排気筒１に嵌着する。該電
池において、内部が減圧状態になつた時の弁体２
の下端縁部４の変形は小さく、従つて排気筒１と
弁体２の間隙部からの外部空気の電池内への進入
を防止することができる。
次に本考案による鉛蓄電池と従来の鉛蓄電池
を、65℃で開路放置（90hrs）した時の陰極板中
の硫酸鉛量を測定した結果は第１表に示すとおり
である。
The present invention relates to an improvement of a small sealed lead-acid battery. Conventional lead-acid batteries have the property of generating hydrogen gas and oxygen gas during charging, and in a method in which the cathode plate absorbs oxygen gas and seals it, the oxygen gas exceeds the oxygen gas absorption capacity of the cathode plate during charging. When gas is generated, it is discharged to the outside of the battery through the exhaust port and the gap between the exhaust pipe and the valve body. However, in a battery as shown in FIG. 1, which has an exhaust pipe 1 that serves as both an electrolyte inlet and an exhaust port, and a cylindrical valve body 2' with a closed top opening,
When the battery is in an open circuit state, oxygen in the battery is absorbed by the cathode plate 3, and the inside of the battery is in a reduced pressure state. At this time, the valve body 2' has a shape as shown in FIG.
External air newly flows into the battery from the gap between the exhaust pipe 1 and the valve body 2', and the oxygen in the air flows into the cathode plate 3.
is absorbed into the cathode plate 3 by further reaction with sulfuric acid.
becomes lead sulfate. In this way, the cycle of absorption of oxygen (leadization of the cathode plate with sulfate) → reduced pressure (deformation of the valve body 2') → inflow of outside air is repeated until the inside of the battery reaches normal pressure with components other than oxygen. This has the disadvantage that the capacity of the cathode plate 3 is reduced. The present invention eliminates the above-mentioned drawbacks,
To provide a lead-acid battery whose cathode plate capacity does not decrease due to being left in an open circuit state. In order to achieve the above object, the present invention makes the lower edge of the valve body protrude outward and increases its wall thickness, thereby preventing the inflow of external air when the inside of the lead-acid battery becomes depressurized. This prevents cancer from decreasing the capacity of the cathode plate. The following invention will be explained. A valve body 2 having a shape as shown in FIG. 3, in which the lower end edge 4 is made to protrude outward and its thickness is made thicker, is fitted into the exhaust pipe 1 of the lid 5. In the battery, the valve body 2 when the internal pressure is reduced
The deformation of the lower end edge 4 is small, and therefore it is possible to prevent external air from entering the battery from the gap between the exhaust pipe 1 and the valve body 2. Next, the amount of lead sulfate in the cathode plates of the lead-acid battery according to the present invention and the conventional lead-acid battery were left open at 65°C for 90 hours, and the results are shown in Table 1.
【表】
上記第１表から明らかなように、酸素ガス吸収
を経て、生成する硫酸鉛は、本考案によれば従来
の鉛蓄電池の半分以下になつている。
上述のように本考案によれば、開路放置による
陰極板の容量低下が蓄しく少なくなる等実用的価
値甚だ大なるものである。[Table] As is clear from Table 1 above, according to the present invention, the amount of lead sulfate produced through absorption of oxygen gas is less than half that of conventional lead-acid batteries. As described above, the present invention has great practical value, such as significantly reducing the decrease in capacity of the cathode plate due to being left open.
【図面の簡単な説明】[Brief explanation of the drawing]
第１図は従来の鉛蓄電池の要部断面図、第２図
は従来の鉛蓄電池における電池内部が減圧状態と
なつたときの弁体の作動状態を示す説明図、第３
図は本考案による鉛蓄電池の要部断面図である。
１は排気筒、２は弁体、４は下端縁部。
Figure 1 is a sectional view of the main parts of a conventional lead-acid battery, Figure 2 is an explanatory diagram showing the operating state of the valve body in a conventional lead-acid battery when the inside of the battery is in a reduced pressure state, and Figure 3
The figure is a sectional view of the main parts of the lead-acid battery according to the present invention. 1 is the exhaust pipe, 2 is the valve body, and 4 is the lower edge.