JP3589427B2

JP3589427B2 - Cylindrical alkaline battery

Info

Publication number: JP3589427B2
Application number: JP29144293A
Authority: JP
Inventors: 誠浦出
Original assignee: Hitachi Maxell Energy Ltd
Current assignee: Hitachi Maxell Energy Ltd
Priority date: 1993-10-26
Filing date: 1993-10-26
Publication date: 2004-11-17
Anticipated expiration: 2019-11-17
Also published as: JPH07122247A

Description

【０００１】
【産業上の利用分野】
本発明は、筒形アルカリ電池に係わり、さらに詳しくは、封口体の樹脂の伸びが大きい場合でも、防爆機構が正常に作動して、高圧下での破裂を防止することができる安全性の高い筒形アルカリ電池に関する。
【０００２】
【従来の技術】
筒形アルカリ電池では、誤って充電したり、あるいは、過放電状態になると、電池内部にガスが発生して、電池内部の圧力が異常に上昇し、電池が破裂するようになる。
【０００３】
そのため、従来からも、図３に示すように、封口体６に防爆用の薄肉部６５を設け、電池内部の圧力が上昇して所定圧力に達すると、上記薄肉部６５が破壊して、電池内部のガスを該薄肉部６５の破壊部分、環状支持体７のガス抜き孔７１および負極端子核８のガス抜き孔８１を通過させて電池外部へ放出し、電池の高圧下での破裂を防止する、いわゆる防爆機能を電池に備えさせることが行われている（例えば、特開昭６３−２３６２５５号公報）。
【０００４】
しかしながら、上記のように封口体６の薄肉部６５が破壊して電池内部のガスを電池外部に放出するには、電池内部の圧力上昇に応じて薄肉部６５の近傍も上方に撓まなければならず、そのため、封口体６の中央部６１と厚肉の外周縁部６２との間にそれらより薄肉の接続部６３を設け、その接続部６３の厚さを０．２〜０．５ｍｍ程度に薄くしている。
【０００５】
そのため、封口体６に伸びの大きい樹脂を使用したり、電池が高温に曝されて封口体６の樹脂が軟化して伸びが大きくなった場合には、電池内部の圧力が比較的低圧で薄肉部６５が破壊に至らないうちに、図４に示すように、接続部６３が電池内部の圧力上昇により伸びて上方に膨らみ環状支持体７に当接して、接続部６３が環状支持体７のガス抜き孔７１を塞ぐため、さらに電池内部の圧力が上昇して薄肉部６５が破壊しても、ガス抜き孔７１が塞がっているために、電池内部のガスを電池外部へ放出することができず、電池が高圧下で破裂するようになる。
【０００６】
【発明が解決しようとする課題】
本発明は、従来の筒形アルカリ電池では、上記のように防爆用の薄肉部６５が破壊するまでの間に封口体６の接続部６３が環状支持体７のガス抜き孔７１を塞ぎ、防爆機能が正常に作動せず、電池が高圧下で破裂したという問題点を解決し、封口体６に伸びの大きい樹脂を使用したり、電池が高温に曝されて封口体６の樹脂が軟化して伸びが大きくなった場合でも、防爆機能が正常に作動して、高圧下での電池破裂を防止することができる安全性の高い筒形アルカリ電池を提供することを目的とする。
【０００７】
【課題を解決するための手段】
上記課題を解決するための本発明の構成を、その実施例に対応する図１〜２を用いて説明すると、本発明は、封口体６の中央部６１と外周縁部６２との間の接続部６３に、先端が環状支持体７側を向く複数個の突起６６を放射状に設けたものである。
【０００８】
すなわち、上記のような突起６６を封口体６に設けていると、電池内部の圧力が上昇し、接続部６３が伸びて上方に膨らんだとしても、環状支持体７には上記突起６６が最初に当接するので、封口体６の突起６６以外の部分と環状支持体７との間には隙間が残り、封口体６の接続部６３によって環状支持体７のガス抜き孔７１が完全に塞がれることはない。
【０００９】
したがって、さらに電池内部の圧力が上昇して、封口体６の薄肉部６５が破壊したときは、電池内部のガスは該薄肉部６５の破壊部分、環状支持体７のガス抜き孔７１、負極端子板８のガス抜き孔８１を通過して電池外部へ放出され、電池の高圧下での破裂が防止され、高い安全性が確保される。
【００１０】
それ故、封口体６にポリプロピレンなどの伸びが大きく安価な樹脂を使用した場合にも、防爆機能が正常に作動して、高い安全性が確保できる。また、電池が高温に曝されて封口体６の樹脂が軟化して伸びが大きくなった場合でも、同様に防爆機能が正常に作動して、高い安全性が確保できる。
【００１１】
上記突起６６による効果をより確実に奏し得るようにするには、突起６６の個数を環状支持体７のガス抜き孔７１の個数より多くし、かつ該ガス抜き孔７１の個数で割り切れない数にしておくことが好ましい。
【００１２】
すなわち、上記のような態様で突起６６を設けておくと、封口体６と環状支持体７との位置合わせのいかんにかかわらず、少なくとも１個の突起６６が環状支持体７のガス抜き孔７１以外の部分に当接することになるので、封口体６の接続部６３が環状支持体７のガス抜き孔７１を完全に塞ぐようなことはない。
【００１３】
また、上記突起６６の幅および突起６６と突起６６との間隔は、環状支持体７のガス抜き孔７１の径より小さいことが好ましい。
【００１４】
すなわち、上記のようにしておけば、封口体６と環状支持体７との位置合せのいかんにかかわらず、封口体６の突起６６が環状支持体７のガス抜き孔７１を完全に塞ぐようなことがなくなり、突起６６により封口体６と環状支持体７との間に環状支持体７のガス抜き孔７１に通じる隙間を作り得る。その結果、防爆用の薄肉部６５が破壊したときに、電池内部のガスは上記隙間、環状支持体７のガス抜き孔７１、負極端子板８のガス抜き孔８１を通って電池外部へ放出され、電池の高圧下での破裂が防止される。
【００１５】
【実施例】
つぎに、本発明の実施例を図面を参照しつつ説明する。ただし、本発明は実施例に例示のもののみに限定されることはない。
【００１６】
図１は本発明の筒形アルカリ電池の一実施例を示す部分断面図であり、図２は図１に示す電池に使用されている封口体を示すもので、（ａ）はその平面図、（ｂ）は上記（ａ）のＡ−Ａ′線における断面図である。なお、電池を示す図においては、各部材の断面後方の輪郭線を図示すると、かえって繁雑化するめ、特に必要なものを除き、断面のみを図示し、断面後方の輪郭線は図示を省略している。
【００１７】
図中、１は正極合剤、２は負極剤、３はセパレータ、４は正極缶、５は負極集電体、６は封口体、７は環状支持体、８は負極端子板、９は外装材である。
【００１８】
正極合剤１は二酸化マンガンと黒鉛を主体とする粉末を円筒状に加圧成形したものであり、負極剤２は亜鉛粉末とアルカリ電解液とゲル剤とを混合して調製した混合物からなるものである。そして、セパレータ３は不織布からなり、正極合剤１と負極剤２を隔離している。
【００１９】
正極缶４は鉄製で表面にニッケルメッキが施されており、上記の正極合剤１、負極剤２、セパレータ３などの発電要素は、この正極缶４に内填されている。負極集電体５は黄銅製で封口体６の透孔６４に挿入され、その頭部は負極端子板８の内面中央部に溶接によって固定されている。
【００２０】
封口体６は、ポリオレフィン系樹脂、ナイロン系樹脂などを射出成形してなる樹脂製で、その形状は中心部に負極集電体５が挿入される透孔６４を設けた厚肉の中央部６１と、正極缶４の開口端部の内周面に接触する厚肉の外周縁部６２と、上記中央部６１と外周縁部６２とを接続する接続部６３からなり、上記接続部６３はその中央部６１側に防爆用の薄肉部６５を有し、その外周縁部６２の近傍にはセパレータ３の開口端部を案内する役割を持つＶ字状部６７を有し、その薄肉部６５とＶ字状部６７との間に突起６６を放射状に８個設けている。
【００２１】
上記突起６６は、その先端が環状支持体７側を向いており、高さは通常０．２〜０．５ｍｍ程度が好ましく、本実施例に示すものは高さが０．３ｍｍにされている。
【００２２】
また、上記突起６６の先端部の幅は環状支持体７のガス抜き孔７１の径より小さいことが好ましく、ＬＲ６形電池では、環状支持体７のガス抜き孔の径が２〜３ｍｍ程度であることから、突起６６の先端部の幅は通常０．５〜２ｍｍ程度にされ、本実施例では０．９ｍｍにされている。また、環状支持体７のガス抜き孔７１の真下部分における突起６６と突起６６との間隔は、環状支持体７のガス抜き孔７１の径より小さいことが好ましく、ガス抜き孔７１の径に応じて通常１〜２ｍｍ程度にされ、本実施例では１．５ｍｍにされている。
【００２３】
環状支持体７は、鉄製であって直径２ｍｍのガス抜き孔７１が放射状に３個設けられていて、前記封口体６の中央部６１と外周縁部６２との間に嵌着されている。
【００２４】
負極端子板８は、鉄製で表面にニッケルメッキを施したものであり、周縁部が鍔状になった帽子状をしており、その天井部から鍔状周縁部に移る周壁部には、ガス抜き孔８１が設けられており、その天井部の内面中央部には前記負極集電体５の頭部が溶接され、その周縁部は正極缶４の開口端部の内方への折曲げにより、封口体６の外周縁部６２の上端部によって環状支持体７の外周縁部に押圧されて固定されている。
【００２５】
外装材９は樹脂シートにアルミニウムを蒸着した樹脂−金属複合シートからなり、正極缶４の外周部を絶縁している。
【００２６】
つぎに、上記実施例の電池と図３に示す従来構造の電池（従来例）に強制充電したときの電池の耐破裂性の相違を調べた。その詳細を試験例１と試験例２において示す。
【００２７】
まず、試験に供する電池は、各電池とも、ＡシリーズとＢシリーズに分け、Ａシリーズでは伸びの大きいポリプロピレン（２３℃での伸び６００％）製の封口体を使用し、２３℃で強制充電試験を行い、これを試験例１とし、Ｂシリーズではナイロン６６（２３℃での伸び２００％）製の封口体を使用し、１２０℃の高温下で強制充電試験を行い、これを試験例２とした。試験例１および試験例２の詳細はそれぞれ次の通りである。
【００２８】
試験例１：
封口体にはポリプロピレン（２３℃の伸び６００％）製のものを使用し、２３℃で強制充電試験を行った。
【００２９】
電池はいずれも外径１４．５ｍｍ、総高５０．５ｍｍのＬＲ６形の筒形アルカリ電池であり、試験に供した電池個数は各２０個で、試験においては、破裂に至った電池個数、ふくれの発生した電池個数および封口体の接続部が伸びて上方に膨らみ環状支持体に当接した電池個数を調べた。
【００３０】
その結果は表１に示す通りであるが、表１では試験に供した全電池中の破裂に至った電池個数などがわかりやすいように、分母に試験に供した全電池個数を示し、分子に破裂に至った電池個数（破裂発生電池個数）、ふくれの発生した電池個数（ふくれ発生電池個数）、封口体の接続部が伸びて上方に膨らみ環状支持体に当接した電池個数（当接電池個数）を示す。
【００３１】
【表１】

【００３２】
表１に示す結果から明らかなように、強制充電した場合、従来構造の電池では、試験に供した２０個の電池のうち１１個の電池にふくれが発生し、６個の電池が破裂したが、本発明の実施例の電池では、破裂やふくれの発生がまったくなく、強制充電した場合にも、高い安全性を確保することができた。
【００３３】
この試験例１に示す結果から、本発明によれば、封口体６に伸びが大きく安価なポリプロピレンを使用した場合でも、強制充電などによる高圧下での電池破裂が防止され、高い安全性を確保できることがわかる。
【００３４】
これは、電池内部の圧力が上昇して、封口体６の接続部６３が伸びて上方に膨らみ、環状支持体７に当接するような状態になった時には、まず、突起６６が環状支持体７に当接し、環状支持体７と封口体６の突起６６以外の部分との間に隙間を残すので、環状支持体７のガス抜き孔７１が封口体６の接続部６３で完全に塞がれることがなくなり、その結果、電池内圧がさらに上昇して薄肉部６５が破壊した時に、電池内部のガスが上記薄肉部６５の破壊部分、環状支持体７のガス抜き孔７１、負極端子板８のガス抜き孔８１を通って電池外部に出て行くことができるからである。
【００３５】
試験例２：
封口体にはナイロン６６（２３℃での伸び２００％）製のものを使用し、強制充電試験を１２０℃の高温下で行った以外は、前記試験例１と同様の条件下でＢシリーズの電池に対して強制充電試験を行った。その結果を表２に示す。なお、試験結果の表示方法は試験例１の場合と同様である。
【００３６】
【表２】

【００３７】
表２に示す結果から明らかなように、高温下で強制充電した場合、封口体６に伸びが小さいナイロン６６を用いていても、従来構造の電池では、試験に供した２０個の電池のうち９個の電池にふくれが発生し、３個の電池が破裂したが、本発明の実施例の電池では、破裂やふくれがまったくなく、高温下で強制充電した場合にも、高い安全性を確保することができた。
【００３８】
この試験例２に示す結果は、封口体６に伸びが小さいナイロン６６を使用していて、電池が高温に曝されて封口体６の樹脂が軟化して伸びが大きくなると、従来構造の電池では、強制充電などにより電池内部にガスが発生して電池内部の圧力が上昇した場合に、封口体６の接続部６３が伸びて上方に膨らみ環状支持体７のガス抜き孔７１を塞ぐため電池が高圧下で破裂することが起こるが、本発明によれば、そのような高温下での強制充電でも、封口体６に設けた突起６６により、電池内部のガスの放出経路が確保され、電池内部のガスを電池外部へ放出することができるので、電池の高圧下での破裂を防止することができ、高い安全性を確保できることを示している。
【００３９】
【発明の効果】
以上説明したように、本発明では、封口体６に先端が環状支持体７側を向く複数個の突起６６を放射状に設けたことにより、封口体６に伸びの大きい樹脂を使用した場合や、電池が高温に曝されて封口体６の樹脂が軟化して伸びが大きくなった場合でも、防爆機能が正常に作動して、電池の高圧下での破裂が防止され、高い安全性を確保することができるようになった。
【００４０】
すなわち、封口体６にポリプロピレンなどの伸びが大きく安価な樹脂を使用した場合でも、電池内部の圧力が上昇し、防爆用の薄肉部６５が破壊する前に封口体６の接続部６３が伸びて上方に膨らみ環状支持体７に当接するような状態になった時に、まず、上記突起６６が環状支持体７に当接し、環状支持体７と封口体６の突起６６以外の部分との間に隙間を残し、封口体６の接続部６３が環状支持体７のガス抜き孔７１を完全に塞ぐようなことがないので、さらに電池内部の圧力が上昇して防爆用の薄肉部６５が破壊したときに電池内部のガスが上記隙間、環状支持体７のガス抜き孔７１などを通って電池外部へ放出され、電池の高圧下での破裂が防止される。
【００４１】
また、電池が高温に曝されて封口体６の樹脂が軟化して伸びが大きくなった場合でも、上記と同様に防爆機能が正常に作動して、高い安全性を確保することができる。
【図面の簡単な説明】
【図１】本発明の筒形アルカリ電池の一実施例を示す部分断面図である。
【図２】図１に示す本発明の実施例の電池に使用した封口体を示すもので、（ａ）はその平面図、（ｂ）は上記（ａ）のＡ−Ａ′線における断面図である。
【図３】従来の筒形アルカリ電池を示す部分断面図である。
【図４】図３に示す従来の筒形アルカリ電池の封口体の接続部が電池内部の圧力上昇により伸びて上方に膨らみ環状支持体に当接し、環状支持体のガス抜き孔を塞いだ状態を示す部分断面図である。
【符号の説明】
１正極合剤
２負極剤
３セパレータ
４正極缶
５負極集電体
６封口体
６１中央部
６２外周縁部
６３接続部
６４透孔
６５薄肉部
６６突起
７環状支持体
７１ガス抜き孔
８負極端子板
８１ガス抜き孔[0001]
[Industrial applications]
The present invention relates to a cylindrical alkaline battery, and more specifically, even when the resin of the sealing body has a large elongation, the explosion-proof mechanism operates normally, and high explosion-proof high pressure can be prevented. It relates to a cylindrical alkaline battery.
[0002]
[Prior art]
In a cylindrical alkaline battery, when charged or erroneously charged, gas is generated inside the battery, the pressure inside the battery abnormally increases, and the battery bursts.
[0003]
Therefore, conventionally, as shown in FIG. 3, an explosion-proof thin portion 65 is provided in the sealing body 6 and when the pressure inside the battery rises and reaches a predetermined pressure, the thin portion 65 is broken and the battery The gas inside is passed through the broken portion of the thin portion 65, the gas vent hole 71 of the annular support 7 and the gas vent hole 81 of the negative electrode terminal core 8, and is discharged to the outside of the battery to prevent the battery from bursting under high pressure. The battery is provided with a so-called explosion-proof function (for example, JP-A-63-236255).
[0004]
However, as described above, in order for the thin portion 65 of the sealing body 6 to break and release the gas inside the battery to the outside of the battery, the vicinity of the thin portion 65 must also bend upward in accordance with the pressure increase inside the battery. Instead, a thinner connecting portion 63 is provided between the central portion 61 of the sealing body 6 and the thicker outer peripheral portion 62, and the thickness of the connecting portion 63 is about 0.2 to 0.5 mm. It is thin.
[0005]
Therefore, when a resin having a large elongation is used for the sealing body 6 or when the battery is exposed to a high temperature and the resin of the sealing body 6 is softened and the elongation is increased, the pressure inside the battery is relatively low and the thin wall is used. Before the portion 65 is broken, as shown in FIG. 4, the connecting portion 63 expands due to a rise in the pressure inside the battery and bulges upward to abut against the annular support 7. Since the gas vent hole 71 is closed, even if the pressure inside the battery further rises and the thin portion 65 is broken, the gas inside the battery can be released to the outside of the battery because the gas vent hole 71 is closed. The battery will burst under high pressure.
[0006]
[Problems to be solved by the invention]
According to the present invention, in the conventional cylindrical alkaline battery, the connection portion 63 of the sealing member 6 closes the gas vent hole 71 of the annular support member 7 until the explosion-proof thin portion 65 is broken as described above, To solve the problem that the function did not work properly and the battery ruptured under high pressure, use a resin with large elongation for the sealing body 6, or the resin of the sealing body 6 was softened due to the battery being exposed to high temperature. It is an object of the present invention to provide a highly safe cylindrical alkaline battery capable of properly operating an explosion-proof function and preventing battery rupture under high pressure even when the elongation increases.
[0007]
[Means for Solving the Problems]
The configuration of the present invention for solving the above problem will be described with reference to FIGS. 1 and 2 corresponding to the embodiment. The present invention provides a connection between a central portion 61 and an outer peripheral edge 62 of a sealing body 6. The portion 63 is provided with a plurality of projections 66 whose tips are directed toward the annular support member 7 in a radial manner.
[0008]
That is, if the projections 66 are provided on the sealing body 6, even if the pressure inside the battery rises and the connecting portion 63 expands and swells upward, the projections 66 are initially formed on the annular support 7. Therefore, a gap remains between the portion other than the projection 66 of the sealing body 6 and the annular support 7, and the connection portion 63 of the sealing body 6 completely closes the gas vent hole 71 of the annular support 7. Will not be.
[0009]
Therefore, when the pressure inside the battery further rises and the thin portion 65 of the sealing body 6 is broken, the gas inside the battery is discharged from the broken portion of the thin portion 65, the gas vent hole 71 of the annular support 7, and the negative electrode terminal. The gas is discharged to the outside of the battery through the gas vent hole 81 of the plate 8, preventing the battery from being ruptured under high pressure, and ensuring high safety.
[0010]
Therefore, even when an inexpensive resin such as polypropylene which is large in expansion is used for the sealing member 6, the explosion-proof function operates normally and high safety can be secured. Further, even when the battery is exposed to a high temperature and the resin of the sealing body 6 is softened and the elongation is increased, the explosion-proof function operates normally and high safety can be secured.
[0011]
In order to ensure that the effect of the projection 66 can be obtained, the number of the projections 66 should be larger than the number of the gas vent holes 71 of the annular support 7 and a number that cannot be divided by the number of the gas vent holes 71. It is preferable to keep it.
[0012]
That is, when the projections 66 are provided in the above-described manner, at least one projection 66 is provided with the gas vent hole 71 of the annular support 7 regardless of the position of the sealing body 6 and the annular support 7. Therefore, the connection portion 63 of the sealing body 6 does not completely block the gas vent hole 71 of the annular support 7.
[0013]
Further, it is preferable that the width of the protrusion 66 and the interval between the protrusion 66 and the protrusion 66 are smaller than the diameter of the gas vent hole 71 of the annular support 7.
[0014]
That is, with the above arrangement, regardless of the position of the sealing body 6 and the annular support 7, the protrusion 66 of the sealing body 6 completely blocks the gas vent hole 71 of the annular support 7. Thus, a gap can be formed between the sealing body 6 and the annular support 7 by the projection 66, which communicates with the gas vent hole 71 of the annular support 7. As a result, when the explosion-proof thin portion 65 is broken, gas inside the battery is discharged to the outside of the battery through the above-mentioned gap, the gas vent hole 71 of the annular support member 7, and the gas vent hole 81 of the negative electrode terminal plate 8. Thus, the battery is prevented from bursting under high pressure.
[0015]
【Example】
Next, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited only to those illustrated in the embodiments.
[0016]
FIG. 1 is a partial cross-sectional view showing one embodiment of the cylindrical alkaline battery of the present invention. FIG. 2 shows a sealing body used in the battery shown in FIG. 1, (a) is a plan view thereof, (B) is a cross-sectional view taken along line AA 'in (a). In the drawings showing the battery, if the outline behind the cross-section of each member is illustrated, it is rather complicated. To avoid complicatedness, only the cross-section is illustrated except for those particularly required, and the outline behind the cross-section is omitted. I have.
[0017]
In the figure, 1 is a positive electrode mixture, 2 is a negative electrode agent, 3 is a separator, 4 is a positive electrode can, 5 is a negative electrode current collector, 6 is a sealing body, 7 is an annular support, 8 is a negative electrode terminal plate, and 9 is an exterior. Material.
[0018]
The positive electrode mixture 1 is obtained by pressing a powder mainly composed of manganese dioxide and graphite into a cylindrical shape, and the negative electrode agent 2 is a mixture prepared by mixing zinc powder, an alkaline electrolyte and a gel agent. It is. The separator 3 is made of a nonwoven fabric, and separates the positive electrode mixture 1 and the negative electrode agent 2.
[0019]
The positive electrode can 4 is made of iron and nickel-plated on the surface. The power generating elements such as the positive electrode mixture 1, the negative electrode agent 2, and the separator 3 are contained in the positive electrode can 4. The negative electrode current collector 5 is made of brass and inserted into the through hole 64 of the sealing body 6, and its head is fixed to the center of the inner surface of the negative electrode terminal plate 8 by welding.
[0020]
The sealing body 6 is made of a resin obtained by injection-molding a polyolefin-based resin, a nylon-based resin, or the like, and has a thick central portion 61 provided with a through hole 64 into which the negative electrode current collector 5 is inserted. And a thick outer peripheral portion 62 that contacts the inner peripheral surface of the opening end of the positive electrode can 4, and a connecting portion 63 that connects the central portion 61 and the outer peripheral edge 62. An explosion-proof thin portion 65 is provided on the central portion 61 side, and a V-shaped portion 67 having a role of guiding the opening end of the separator 3 is provided near the outer peripheral edge portion 62. Eight protrusions 66 are provided radially between the V-shaped portion 67 and the V-shaped portion 67.
[0021]
The protrusion 66 has a tip directed toward the annular support member 7 and preferably has a height of usually about 0.2 to 0.5 mm, and the height shown in this embodiment is 0.3 mm. .
[0022]
The width of the tip of the protrusion 66 is preferably smaller than the diameter of the gas vent hole 71 of the annular support 7. In the LR6 type battery, the diameter of the gas vent of the annular support 7 is about 2 to 3 mm. Therefore, the width of the tip of the projection 66 is usually about 0.5 to 2 mm, and is 0.9 mm in this embodiment. It is preferable that the distance between the protrusions 66 in the portion just below the gas vent hole 71 of the annular support 7 is smaller than the diameter of the gas vent hole 71 of the annular support 7, Usually, it is about 1 to 2 mm, and in this embodiment, it is 1.5 mm.
[0023]
The annular support member 7 is made of iron and has three radially provided gas vent holes 71 having a diameter of 2 mm, and is fitted between the central portion 61 and the outer peripheral edge portion 62 of the sealing body 6.
[0024]
The negative electrode terminal plate 8 is made of iron and nickel-plated on its surface, has a hat-like shape with a peripheral edge formed in a flange shape, and has a gas-injected peripheral wall portion that moves from the ceiling to the flange-shaped peripheral edge portion. A hole 81 is provided, the head of the negative electrode current collector 5 is welded to the center of the inner surface of the ceiling, and the peripheral portion is bent inward at the open end of the positive electrode can 4. The upper end of the outer peripheral edge 62 of the sealing body 6 is pressed against and fixed to the outer peripheral edge of the annular support 7.
[0025]
The exterior material 9 is formed of a resin-metal composite sheet obtained by evaporating aluminum on a resin sheet, and insulates the outer periphery of the positive electrode can 4.
[0026]
Next, the difference in rupture resistance between the battery of the above example and the battery of the conventional structure (conventional example) shown in FIG. 3 when forcibly charged was examined. The details are shown in Test Examples 1 and 2.
[0027]
First, the batteries to be tested are divided into A series and B series for each battery, and the A series uses a sealing material made of polypropylene with a large elongation (elongation at 23 ° C .: 600%) and a forced charging test at 23 ° C. This is referred to as Test Example 1. In the B series, a forced charging test was performed at a high temperature of 120 ° C. using a sealing body made of nylon 66 (elongation at 23 ° C .: 200%). did. The details of Test Example 1 and Test Example 2 are as follows.
[0028]
Test example 1:
The sealing body was made of polypropylene (elongation at 23 ° C .: 600%), and a forced charging test was performed at 23 ° C.
[0029]
Each of the batteries was an LR6 cylindrical alkaline battery having an outer diameter of 14.5 mm and a total height of 50.5 mm. The number of batteries used in the test was 20 each. And the number of batteries in which the connecting portion of the sealing member extended and swelled upward to contact the annular support was examined.
[0030]
The results are as shown in Table 1. In Table 1, the denominator indicates the total number of batteries subjected to the test, and the numerator indicates the number of all batteries subjected to the test. The number of batteries that reached (the number of batteries that ruptured), the number of batteries that generated blisters (the number of batteries that generated blisters), and the number of batteries that extended the connecting part of the sealing body and swelled upward to contact the annular support (the number of abutting batteries) ).
[0031]
[Table 1]

[0032]
As is evident from the results shown in Table 1, when the battery was forcibly charged, in the battery of the conventional structure, 11 of the 20 batteries tested underwent blistering and 6 of the batteries burst. In the battery according to the example of the present invention, no rupture or swelling occurred, and high safety was ensured even when the battery was forcibly charged.
[0033]
From the results shown in Test Example 1, according to the present invention, even in the case where inexpensive polypropylene having large elongation is used for the sealing body 6, battery rupture under high pressure due to forced charging or the like is prevented, and high safety is secured. We can see that we can do it.
[0034]
This is because when the pressure inside the battery rises, the connecting portion 63 of the sealing body 6 expands and swells upward, and comes into contact with the annular support 7, first, the protrusion 66 is moved to the annular support 7. , And a gap is left between the annular support 7 and the portion other than the projection 66 of the sealing body 6, so that the gas vent hole 71 of the annular support 7 is completely closed by the connecting portion 63 of the sealing body 6. As a result, when the internal pressure of the battery further rises and the thin portion 65 is broken, the gas inside the battery flows through the broken portion of the thin portion 65, the gas vent hole 71 of the annular support 7, and the negative electrode terminal plate 8. This is because it is possible to go out of the battery through the gas vent hole 81.
[0035]
Test example 2:
The sealing member was made of nylon 66 (elongation at 23 ° C .: 200%), and the B series was used under the same conditions as in Test Example 1 except that the forced charging test was performed at a high temperature of 120 ° C. The battery was subjected to a forced charging test. Table 2 shows the results. The method of displaying the test results is the same as that of Test Example 1.
[0036]
[Table 2]

[0037]
As is evident from the results shown in Table 2, when the battery was forcibly charged at a high temperature, even if nylon 66 having a small elongation was used for the sealing member 6, the battery of the conventional structure did not Blistering occurred in nine batteries and three batteries exploded, but the batteries of the examples of the present invention have no rupture or swelling and ensure high safety even when forcibly charged at high temperatures. We were able to.
[0038]
The results shown in Test Example 2 show that when the sealing body 6 is made of nylon 66 having a small elongation and the battery is exposed to a high temperature, the resin of the sealing body 6 is softened and the elongation is increased, the battery of the conventional structure has In the case where gas is generated inside the battery due to forced charging or the like and the pressure inside the battery rises, the connection portion 63 of the sealing body 6 expands and bulges upward to close the gas vent hole 71 of the annular support member 7, so that the battery is Although rupture occurs under high pressure, according to the present invention, even in such a forced charging under high temperature, the projection 66 provided on the sealing body 6 secures a gas discharge path inside the battery, and Can be released to the outside of the battery, so that the battery can be prevented from bursting under high pressure, and high safety can be ensured.
[0039]
【The invention's effect】
As described above, in the present invention, by providing a plurality of protrusions 66 whose tip faces the annular support member 7 in the radial direction on the sealing body 6, when the sealing body 6 is made of a resin having a large expansion, Even when the battery is exposed to high temperature and the resin of the sealing body 6 is softened and the elongation is increased, the explosion-proof function operates normally and the battery is prevented from rupture under high pressure, ensuring high safety. Now you can do it.
[0040]
That is, even when a resin such as polypropylene, which has a large elongation and is inexpensive, is used for the sealing member 6, the pressure inside the battery increases, and the connecting portion 63 of the sealing member 6 expands before the explosion-proof thin portion 65 is broken. When the projection 66 bulges upward and comes into contact with the annular support 7, first, the projection 66 comes into contact with the annular support 7, and the space between the annular support 7 and the portion other than the projection 66 of the sealing body 6. Since a gap is left and the connection portion 63 of the sealing body 6 does not completely block the gas vent hole 71 of the annular support 7, the internal pressure of the battery further increases, and the explosion-proof thin portion 65 is broken. Occasionally, the gas inside the battery is released to the outside of the battery through the gap, the gas vent hole 71 of the annular support 7, and the like, so that the battery is prevented from bursting under high pressure.
[0041]
Further, even when the battery is exposed to a high temperature and the resin of the sealing body 6 is softened and the elongation is increased, the explosion-proof function operates normally as described above, and high safety can be secured.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view showing one embodiment of a cylindrical alkaline battery of the present invention.
FIGS. 2A and 2B show a sealing body used in the battery of the embodiment of the present invention shown in FIG. 1, wherein FIG. 2A is a plan view thereof, and FIG. 2B is a cross-sectional view taken along the line AA ′ in FIG. It is.
FIG. 3 is a partial sectional view showing a conventional cylindrical alkaline battery.
FIG. 4 shows a state in which a connection portion of a sealing body of the conventional cylindrical alkaline battery shown in FIG. 3 is extended due to a rise in pressure inside the battery and bulges upward to abut against an annular support, thereby closing a gas vent hole of the annular support. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Positive electrode mixture 2 Negative electrode agent 3 Separator 4 Positive electrode can 5 Negative current collector 6 Sealing body 61 Center part 62 Outer edge 63 Connection part 64 Through hole 65 Thin part 66 Protrusion 7 Annular support 71 Gas vent hole 8 Negative electrode terminal plate 81 Gas vent hole

Claims

The opening of the positive electrode can 4 that the inner Hama power generating element, a resin sealing body provided thin portion (65) of the explosion-proof and (6), the sealing body has a gas vent hole (71) (6) A cylindrical alkaline battery sealed with an annular support ( 7 ) serving as a support for the negative electrode current collector ( 5 ) inserted into the through hole ( 64 ) in the central part ( 61 ) of the sealing body ( 6 ). in, cylindrical alkaline batteries, characterized by comprising a plurality of protrusions tip to the sealing body (6) faces the annular support (7) side (66) radially.

The projection (66), cylindrical alkaline according to claim 1, characterized in that provided in the connecting portion (63) between the central portion (61) the outer peripheral edge portion (62) of the sealing member (6) battery.

The number of protrusions ( 66 ) of the sealing body ( 6 ) is larger than the number of vent holes ( 71 ) of the annular support ( 7 ) and is not divisible by the number of vent holes ( 71 ). The cylindrical alkaline battery according to claim 1, wherein:

The width of the projection ( 66 ) of the sealing body ( 6 ) and the distance between the projection ( 66 ) and the projection ( 66 ) are smaller than the diameter of the gas vent hole ( 71 ) of the annular support ( 7 ). Item 2. A cylindrical alkaline battery according to Item 1.