JP4958163B2

JP4958163B2 - Alkaline battery

Info

Publication number: JP4958163B2
Application number: JP2007072433A
Authority: JP
Inventors: 誠浦出; 昭一郎立石; 浩二小出; 真一岩本; 三七十郎牛島
Original assignee: Hitachi Maxell Energy Ltd
Current assignee: Hitachi Maxell Energy Ltd
Priority date: 2000-09-01
Filing date: 2007-03-20
Publication date: 2012-06-20
Anticipated expiration: 2021-08-10
Also published as: JP2007180052A

Description

本発明は、筒形アルカリ乾電池の封止技術に関する。 The present invention relates to a sealing technique for cylindrical alkaline batteries.

〈筒形アルカリ乾電池の全体概略構造〉
従来の筒形アルカリ乾電池の基本構造は、例えば特許文献１に記載されており、公知である。そこでは、図９に示すように、正極端子を兼ねる有底円筒状の外装缶１の内部（セル室Ｃ）に、正極２および負極４と、これらの間に配置されるセパレータ３と、負極４に挿入される釘状の負極集電棒５と、セパレータ３および正極２に含浸される電解液（図示せず）とを収容し、セル室Ｃ内の電解液が外部に漏れ出ないように外装缶１の開口端部１ａを封口した構成とされている。 <Overall schematic structure of cylindrical alkaline battery>
The basic structure of a conventional cylindrical alkaline battery is described in Patent Document 1, for example, and is well known. 9, as shown in FIG. 9, a positive electrode 2, a negative electrode 4, a separator 3 disposed therebetween, and a negative electrode are disposed inside (cell chamber C) of a bottomed cylindrical outer can 1 that also serves as a positive electrode terminal. The nail-like negative electrode current collecting rod 5 inserted into the electrode 4 and the electrolyte (not shown) impregnated in the separator 3 and the positive electrode 2 are accommodated so that the electrolyte in the cell chamber C does not leak to the outside. The opening end 1a of the outer can 1 is sealed.

〈外装缶の缶厚み〉
筒形アルカリ乾電池の一つである単三形アルカリ乾電池の外径はＪＩＳ規格では１3.５〜１4.５mmと定められているが、電池を使用する機器の電池ホルダの寸法が統一されていて、外径は１4.０±0.１mmが事実上の標準となっている。外径が制限されている中で、アルカリ乾電池の内容積（セル容積）を増やして放電容量のアップを図るには、外装缶の缶厚みを減らせば良い。しかし、アルカリ乾電池で一般に使用されているキルド鋼板（アルミキルド鋼板）製の外装缶の缶厚みを薄くすると、加工しにくくなったり、外装缶の輸送過程や電池組み立て時の搬送工程で外装缶が変形したりするなどの問題が起こりやすくなる。このため、現在国内で販売されている単三形アルカリ乾電池の外装缶の缶厚みは、最も薄いものでも0.１８mmとなっている。 <Outer can thickness>
The outer diameter of AA alkaline batteries, one of the cylindrical alkaline batteries, is defined as 13.5 to 14.5 mm according to JIS standards, but the dimensions of the battery holders of the equipment that uses the batteries are uniform. The outer diameter of 14.0 ± 0.1mm is the de facto standard. In order to increase the discharge capacity by increasing the inner volume (cell volume) of the alkaline battery while the outer diameter is limited, the thickness of the outer can can be reduced. However, if the can thickness of the outer can made of killed steel plate (aluminum killed steel plate) commonly used in alkaline batteries is made thin, it becomes difficult to process, and the outer can is deformed during the transport process of the outer can and the battery assembly process. Problems occur. For this reason, the thickness of the outer can of AA alkaline batteries currently sold in Japan is 0.18 mm even at the thinnest.

〈封口部分の構造〉
筒形アルカリ乾電池における封口部分には、図１０に拡大して示すように、内圧の異常上昇防止用つまり防爆用の安全弁機構を有する樹脂製封口体６と、これを内周から支える支持手段１０７と、図中の上方に向けて凸状（ハット状）に形成された負極端子板（負極端子）２０７とが装着されている。このうち、樹脂製封口体６は、負極集電棒５を保持するボス部６１と、外装缶１の内周面と接する外周部６２と、一部に防爆用の薄肉部分（安全弁の作動点）６３ａが設けられてボス部６１と外周部６２とを連結する連結部６３とで構成されている。そして、電池の内圧つまりセル室Ｃ内の圧力が所定レベル以上に上昇したときに、連結部６３が例えば図中の鎖線で示すように膨張変形し、さらに内圧が上昇したときに図１１に示すように防爆用の薄肉部分６３ａが破断する（すなわち安全弁が作動する）ことにより、内圧を外部に逃がすようになっている。また、樹脂製封口体６は、セル室Ｃの上方を封鎖して電解液の漏出を防止するとともに、正極集電体となる外装缶１と負極集電体端子である負極端子板２０７との間を電気的に絶縁する。なお、図１０および図１１において符号１０７ｆおよび２０７ｆは、セル室Ｃ内で発生したガスを外部に放出するためのガス抜き孔をそれぞれ示している。 <Structure of the sealing part>
As shown in an enlarged view in FIG. 10, the sealing portion of the cylindrical alkaline battery includes a resin sealing body 6 having a safety valve mechanism for preventing abnormal increase in internal pressure, that is, explosion-proof, and support means 107 for supporting this from the inner periphery. And a negative electrode terminal plate (negative electrode terminal) 207 formed in a convex shape (hat shape) toward the upper side in the figure. Among these, the resin sealing body 6 includes a boss portion 61 that holds the negative electrode current collector rod 5, an outer peripheral portion 62 that is in contact with the inner peripheral surface of the outer can 1, and a thin portion for explosion protection (operation point of the safety valve). 63a is provided and includes a connecting portion 63 that connects the boss portion 61 and the outer peripheral portion 62. When the internal pressure of the battery, that is, the pressure in the cell chamber C rises to a predetermined level or more, the connecting portion 63 expands and deforms as shown by, for example, a chain line in the figure, and when the internal pressure further rises, it is shown in FIG. As described above, the explosion-proof thin portion 63a is broken (that is, the safety valve is activated), so that the internal pressure is released to the outside. In addition, the resin sealing body 6 seals the upper part of the cell chamber C to prevent leakage of the electrolytic solution, and between the outer can 1 serving as the positive electrode current collector and the negative electrode terminal plate 207 serving as the negative electrode current collector terminal. Insulate the gap electrically. 10 and 11, reference numerals 107f and 207f denote gas vent holes for releasing the gas generated in the cell chamber C to the outside, respectively.

このような樹脂製封口体６は、これの外周部６２が支持手段１０７と外装缶１との間に位置した状態で外装缶１の開口端部１ａの周縁部分とともに内側に締め付けられてかしめられることによって、外装缶１の開口端部１ａ内に装着される（このような封口方法を、この明細書では「横締めによる封口」または「横締め封口」という）。その場合、かしめる力が弱ければ、最初のうちは電池内部の電解液（水酸化カリウムを主成分とする強アルカリ液）が漏れ出なかったとしても、その後の温度変化などによって封口体６と外装缶１との間の密着性が低下し、やがては電池内部の電解液が封口体６と外装缶１との境界部分から外部に浸み出してくる。そこで、従来の筒形アルカリ乾電池においては、封口体６を内周から支える支持手段１０７として、所要の厚み（通常、0.６〜0.７５mm程度）を有する金属ワッシャ（中央部に孔を有する円盤状の金属板）が使用されており、封口体６の外周部６２を締め付ける際にその内側から金属ワッシャでしっかりとバックアップすることによって、外装缶１の開口端部１ａとともに封口体６の外周部６２を外側から十分な力でかしめることができるようにしている。 Such a resin-made sealing body 6 is clamped inside and crimped together with the peripheral edge portion of the open end 1a of the outer can 1 in a state where the outer peripheral portion 62 thereof is located between the support means 107 and the outer can 1. By this, it is mounted in the open end 1a of the outer can 1 (this sealing method is referred to as “sealing by side fastening” or “lateral sealing” in this specification). In that case, if the caulking force is weak, even if the electrolytic solution (strong alkaline solution mainly composed of potassium hydroxide) in the battery does not leak at first, Adhesiveness with the outer can 1 is lowered, and eventually the electrolyte inside the battery oozes out from the boundary between the sealing body 6 and the outer can 1. Therefore, in a conventional cylindrical alkaline battery, a metal washer having a required thickness (usually about 0.6 to 0.75 mm) (having a hole in the central portion) is used as the supporting means 107 that supports the sealing body 6 from the inner periphery. Disc-shaped metal plate) is used, and when the outer peripheral portion 62 of the sealing body 6 is tightened, the outer periphery of the sealing body 6 is sealed together with the opening end 1a of the outer can 1 by firmly backing up from the inside with a metal washer. The part 62 can be caulked from the outside with a sufficient force.

特開平８−２２２１８９号公報JP-A-8-222189

アルカリ乾電池を組み立てる際、先に述べたように樹脂製封口体６は、これに負極集電棒５や負極端子板２０７などを組み付けた後、外装缶１の開口端部１ａ内に挿入され、その状態で封口体６の外周部６２が外周から外装缶１、内周から金属ワッシャ（金属板）１０７により締め付けられて、かしめられることにより、外装缶１の開口端部１ａ内に装着される。このとき封口体樹脂が変形し、その弾性力で封口体６の外周部６２が外装缶１の内面に押し当てられて密着する。 When assembling the alkaline battery, the resin sealing body 6 is inserted into the open end 1a of the outer can 1 after assembling the negative electrode current collecting rod 5, the negative electrode terminal plate 207, etc. In this state, the outer peripheral portion 62 of the sealing body 6 is fastened by the outer can 1 from the outer periphery and is crimped by the metal washer (metal plate) 107 from the inner periphery, so that it is mounted in the open end 1 a of the outer can 1. At this time, the sealing body resin is deformed, and the outer peripheral portion 62 of the sealing body 6 is pressed against the inner surface of the outer can 1 by the elastic force to be in close contact.

ところが、連結部６３の厚みが比較的薄く、しかもその外周部６２側の部分とボス部６１側の部分との肉厚差があまり大きくない従来の封口体構造では、横締めによる封口時に封口体６あるいはその連結部６３が全体的に大きく変形し、連結部６３における防爆用の薄肉部分（安全弁の作動点）６３ａに負担がかかりすぎる、つまり当該薄肉部分６３ａに応力がかかり過ぎるという問題がある。 However, in the conventional sealing body structure in which the thickness of the connecting portion 63 is relatively thin and the thickness difference between the outer peripheral portion 62 side portion and the boss portion 61 side portion is not so large, 6 or its connecting part 63 is greatly deformed as a whole, and there is a problem that the explosion-proof thin part (operation point of the safety valve) 63a is excessively loaded, that is, the thin part 63a is excessively stressed. .

加えて、樹脂製封口体６を備えたアルカリ乾電池において、安全弁が正常に作動すると、内部のガスは金属ワッシャ１０７や負極端子板２０７に設けられたガス抜き孔１０７ｆ、２０７ｆを通って外部に抜ける。安全弁は、電池の内圧上昇により封口体６の連結部が上方に撓み、内圧が所定圧以上となったときに、連結部６３に設けられている防爆用の薄肉部分６３ａが剪断されることにより作動する。 In addition, in the alkaline battery equipped with the resin sealing body 6, when the safety valve operates normally, the internal gas escapes to the outside through the gas vent holes 107f and 207f provided in the metal washer 107 and the negative electrode terminal plate 207. . When the internal pressure of the battery causes the connecting portion of the sealing body 6 to bend upward and the internal pressure becomes a predetermined pressure or higher, the explosion-proof thin portion 63a provided in the connecting portion 63 is sheared. Operate.

しかし、従来の封口体構造によると、連結部６３の厚みが比較的薄く、しかもその外周部６２側の部分とボス部６１側の部分とであまり大きな肉厚差が無かったため、例えば短絡発熱時においては封口体樹脂が軟化し、その結果、安全弁が作動する前に連結部６３が伸びて金属ワッシャ１０７のガス抜き孔１０７ａを塞いでしまったり、また支持手段に金属ワッシャでは負極端子板２０７を使用した場合には負極端子板２０７に接触したりして、内部のガスがスムーズに抜けないという問題が生じる。さらに、過放電放置時には、安全弁が正常に作動せずに封口体６が破裂し、これに伴って内容物が飛散したり大きな破裂音が生じたりする。 However, according to the conventional sealing body structure, the thickness of the connecting portion 63 is relatively thin, and there is no great difference in thickness between the outer peripheral portion 62 side and the boss portion 61 side. In this case, the sealing body resin softens, and as a result, the connecting portion 63 extends before the safety valve operates to block the gas vent hole 107a of the metal washer 107. When it is used, there is a problem that the internal gas does not smoothly escape due to contact with the negative electrode terminal plate 207. Further, when left overdischarged, the sealing body 6 is ruptured without the safety valve being normally operated, and accordingly, the contents are scattered or a loud burst sound is generated.

本発明は、アルカリ乾電池において、横締め封口時に防爆用の薄肉部分に作用する応力を低減させることにより、安全弁として機能する当該薄肉部分の信頼性を向上させることを目的とする。
本発明の他の目的は、アルカリ乾電池において、樹脂製封口体の形状を変更することにより、安全弁が正常に作動するようにして、短絡発熱時や過放電放置時における安全性を向上させることにある。 An object of the present invention is to improve the reliability of the thin portion that functions as a safety valve by reducing the stress acting on the thin portion for explosion-proofing at the time of lateral fastening in an alkaline dry battery.
Another object of the present invention is to improve safety during short-circuit heat generation or overdischarge by allowing the safety valve to operate normally by changing the shape of the resin sealing body in an alkaline battery. is there.

〈請求項１に係る発明〉
樹脂製封口体の支持手段に負極端子板を使用したアルカリ乾電池において、これの横締め封口時に樹脂製封口体に設けられた防爆用の薄肉部分に負担がかかるのは、従来の封口体では、連結部の肉厚が防爆用の薄肉部分以外は比較的一様で、連結部に作用する応力を当該連結部全体で受ける構造となっており、結果的に防爆用の薄肉部分に応力が集中する構造となっていたからであると思われる。 <Invention according to claim 1>
In an alkaline battery using a negative electrode terminal plate as a support means for a resin sealing body, a load is applied to the thin explosion-proof portion provided in the resin sealing body at the time of lateral sealing of this, in the conventional sealing body, The thickness of the connecting part is relatively uniform except for the explosion-proof thin part, and the structure is such that the stress acting on the connecting part is received by the entire connecting part. As a result, the stress is concentrated on the explosion-proof thin part. This is thought to be because of the structure.

そこで、本発明では、樹脂製封口体の支持手段に負極端子板を使用したアルカリ乾電池において、封口体の連結部に横締め封口時における応力の一部を吸収する相対的に薄肉状の応力吸収部を設けることより、防爆用の薄肉部分への応力集中を防止する。具体的には、本発明は、図１に示すように有底円筒状の外装缶１の内部に、正極２および負極４と、これらの間に配置されるセパレータ３と、電解液（図示せず）とを収容し、外装缶１の開口端部１ａ内に、樹脂製封口体６とこれを内周から支える支持手段とを装着して、外装缶１と支持手段とで樹脂製封口体６を締め付けることにより外装缶１の開口端部１ａを封口したアルカリ乾電池において、以下の構成としたものである。 Therefore, in the present invention, in an alkaline battery using a negative electrode terminal plate as a supporting means for a resin sealing body, a relatively thin-walled stress absorption that absorbs part of the stress at the time of side-sealing sealing at the connecting portion of the sealing body. By providing a portion, stress concentration on the thin-walled portion for explosion protection is prevented. Specifically, as shown in FIG. 1, the present invention includes a positive electrode 2 and a negative electrode 4, a separator 3 disposed therebetween, and an electrolyte (not shown) in a bottomed cylindrical outer can 1. The resin sealing body 6 and supporting means for supporting it from the inner periphery are mounted in the open end 1a of the outer can 1, and the resin sealing body is composed of the outer can 1 and the supporting means. The alkaline dry battery in which the open end 1a of the outer can 1 is sealed by tightening 6 is configured as follows.

すなわち、まず放電容量の増大を図るために、図２に拡大して示すように前記支持手段として、負極端子板を兼ねた１枚の金属板７（負極端子板７）を使用する。その上で、前記樹脂製封口体６については、負極４の中心部に挿入される負極集電棒５を保持するボス部６１と、前記負極端子板（支持手段７）によって内周から支えられて外装缶１の内周面と接する外周部６２と、ボス部６１と外周部６２とを連結する連結部６３とを具備した構成とする。この樹脂製封口体６の連結部６３には、前記ボス部６１側の付け根部分に防爆用の薄肉部分６３ａを設ける。そして、横締め封口時における防爆用の薄肉部分６３ａへの負担を軽減するために、連結部６３における前記外周部６２側の付け根部分に、外装缶１の開口端部１ａを封口すべく樹脂製封口体６を締め付けたときに前記防爆用の薄肉部分６３ａに応力が集中しないように当該連結部６３に作用する応力の一部を吸収する応力吸収部６３ｃを設ける。この応力吸収部６３ｃは、これの直ぐ内周側に位置する部分６３ｄに比べて肉厚が不連続に薄くなるように且つ前記内周側に位置する部分６３ｄとの間に段差を有するように形成する。 That is, first, in order to increase the discharge capacity, as shown in an enlarged view in FIG. 2, a single metal plate 7 (negative electrode terminal plate 7) that also serves as a negative electrode terminal plate is used as the support means. In addition, the resin sealing body 6 is supported from the inner periphery by a boss portion 61 that holds the negative electrode current collector rod 5 inserted in the center of the negative electrode 4 and the negative electrode terminal plate (support means 7). The outer peripheral portion 62 that is in contact with the inner peripheral surface of the outer can 1 and the connecting portion 63 that connects the boss portion 61 and the outer peripheral portion 62 are provided. The connecting portion 63 of the resin sealing body 6 is provided with an explosion-proof thin portion 63a at the base portion on the boss portion 61 side. And in order to reduce the burden on the explosion-proof thin-walled portion 63a at the time of lateral fastening, a resin-made product is used to seal the opening end 1a of the outer can 1 at the base portion on the outer peripheral portion 62 side of the connecting portion 63. A stress absorbing portion 63c that absorbs a part of the stress acting on the connecting portion 63 is provided so that the stress is not concentrated on the explosion-proof thin portion 63a when the sealing body 6 is tightened. The stress absorbing portion 63c has a step difference between the stress absorbing portion 63c and the portion 63d positioned on the inner peripheral side so that the thickness thereof is discontinuously thinner than the portion 63d positioned on the inner peripheral side. Form.

短絡発熱等による高温時や過放電放置時に樹脂製封口体における安全弁が正常に作動しないのは、安全弁が作動する前、すなわち連結部における防爆用の薄肉部分が破断する前に、封口体の連結部がドーム状に大きく膨らみ、その状態で金属ワッシャあるいは負極端子板（金属ワッシャを設けない場合）に接触してしまうからであると考えられる。つまり、本来ならば金属ワッシャあるいは負極端子板に接触する前に封口体の連結部における防爆用の薄肉部分が破断しなければならないのに、封口体の連結部の肉厚が全体的に比較的薄い等の形状上あるいは構造上の理由により連結部がドーム状に変形し、薄肉部分の破断が起こる前にドーム状となった連結部が破裂してしまうのである。 The reason why the safety valve in the resin sealing body does not operate normally at high temperatures due to short-circuit heat generation, etc., when it is left overdischarged is to connect the sealing body before the safety valve operates, that is, before the explosion-proof thin-walled portion breaks. This is probably because the portion swells in a dome shape and contacts the metal washer or the negative electrode terminal plate (in the case where no metal washer is provided) in that state. In other words, although the explosion-proof thin portion of the connecting portion of the sealing body must be broken before contacting the metal washer or the negative electrode terminal plate, the thickness of the connecting portion of the sealing body is relatively relatively small overall. The connecting portion is deformed into a dome shape due to a thin shape or a structural reason, and the dome-shaped connecting portion is ruptured before the thin portion is broken.

〈請求項２、３に係る各発明〉
請求項２および３に係る各発明は、安全弁の信頼性をより一層向上させようとするものである。すなわち、前記のようなボス部６１と外周部６２と連結部６３とを具備した樹脂製封口体６を有するアルカリ乾電池において、樹脂製封口体６の連結部６３における前記ボス部６１側の付け根部分に、これを取り囲んでいる直ぐ外側の第１肉厚部分６３ｂに比べて肉厚が不連続に薄くなるように且つ第１肉厚部分６３ｂとの間に段差を有するように形成された防爆用の薄肉部分６３ａを設けたこと、および連結部６３における前記外周部６２側の付け根部分に、外装缶１の開口端部１ａを封口すべく樹脂製封口体６を締め付けたときに前記防爆用の薄肉部分６３ａに応力が集中しないように当該連結部６３に作用する応力の一部を吸収する応力吸収部６３ｃを設け、この応力吸収部６３ｃを、これの直ぐ内周側に位置する第２肉厚部分６３ｄに比べて肉厚が不連続に薄くなるように且つ第２肉厚部分６３ｄとの間に段差を有するように形成したことを特徴とするものである。 <Each invention according to claims 2 and 3 >
The inventions according to claims 2 and 3 are intended to further improve the reliability of the safety valve. That is, in the alkaline dry battery having the resin sealing body 6 provided with the boss portion 61, the outer peripheral portion 62, and the connecting portion 63 as described above, the base portion on the boss portion 61 side in the connecting portion 63 of the resin sealing body 6. In addition, the explosion-proof material is formed so that the thickness is discontinuously thin compared to the first thick portion 63b immediately outside surrounding the first thick portion 63b and there is a step between the first thick portion 63b. And when the resin sealing body 6 is tightened to seal the opening end 1a of the outer can 1 at the base portion of the connecting portion 63 on the outer peripheral portion 62 side. A stress absorbing portion 63c that absorbs part of the stress acting on the connecting portion 63 is provided so that stress is not concentrated on the thin-walled portion 63a, and the stress absorbing portion 63c is disposed on the inner peripheral side of the second wall. Thick part 63d It is characterized in that the wall thickness is formed to have a step between the and so discontinuous thin second thick portion 63d than.

この場合、第１肉厚部分６３ｂの肉厚を0.４〜0.５mmとし、第２肉圧部分６３ｄの肉厚を第１肉厚部分６３ｂの肉厚の2.５〜3.０倍に設定するのが望ましい（請求項３）。樹脂製封口体６の支持手段に負極端子板７を使用した単三形アルカリ乾電池においては、封口体６の連結部６３が負極端子板７に接触するまでの撓み量（変位量）は1.２mmである。樹脂製封口体（例えば６，６ナイロン製封口体）６において、第１肉厚部分６３ｂおよび第２肉厚部分６３ｄの各肉厚を前記のように比較的厚目に設定しておくと、温度１５０〜２００℃の条件で連結部６３の撓み量を1.２mm以下、連結部６３の内部応力を１００mmＮｓ（従来構造の約６０％）以下にすることができる。これにより、高温時（１５０〜２００℃）に防爆用の薄肉部分６３ａが破断する前に封口体６がドーム状に膨らんで負極端子板７に接触したり過放電放置時に封口体６が破断したりする事態を防止できる。 In this case, the thickness of the first thick portion 63b is 0.4 to 0.5 mm, and the thickness of the second thick pressure portion 63d is 2.5 to 3.0 times the thickness of the first thick portion 63b. It is desirable to set to (Claim 3 ). In an AA alkaline battery using the negative electrode terminal plate 7 as a supporting means for the resin sealing member 6, the amount of deflection (displacement) until the connecting portion 63 of the sealing member 6 contacts the negative electrode terminal plate 7 is 1. 2 mm. In the resin sealing body (for example, 6,6 nylon sealing body) 6, when the thicknesses of the first thick portion 63b and the second thick portion 63d are set relatively thick as described above, Under the condition of a temperature of 150 to 200 ° C., the bending amount of the connecting portion 63 can be 1.2 mm or less, and the internal stress of the connecting portion 63 can be 100 mm Ns (about 60% of the conventional structure) or less. As a result, the sealing body 6 swells in a dome shape before the thin explosion-proof portion 63a breaks at high temperatures (150 to 200 ° C.) and contacts the negative terminal plate 7 or breaks when left overdischarged. Can be prevented.

本発明のアルカリ乾電池においては、以下に述べるように、樹脂製封口体６の形状ないし構造を改良したことによって、封口体６の連結部６３に設けた防爆用の薄肉部分６３ａにより構成される安全弁を確実かつ正常に作動させることができ、その信頼性や安全性を高めることができる。 In the alkaline dry battery of the present invention, as described below, a safety valve constituted by an explosion-proof thin-walled portion 63a provided in the connecting portion 63 of the sealing body 6 by improving the shape or structure of the resin sealing body 6. Can be reliably and normally operated, and its reliability and safety can be improved.

まず、図２に示すように、封口体６の連結部６３における外周部６２側の付け根部分に応力吸収部６３ｃを設け、この応力吸収部６３ｃで、横締め封口時に連結部６３に作用する応力の一部を吸収するようにしたことにより、横締め封口時における防爆用の薄肉部分６３ａへの応力集中を防止できる。これにより、安全弁の作動圧が変動することを抑制でき、そのぶんだけ安全弁の信頼性を高めることができる。 First, as shown in FIG. 2, a stress absorbing portion 63 c is provided at the base portion on the outer peripheral portion 62 side of the connecting portion 63 of the sealing body 6, and the stress acting on the connecting portion 63 at the time of lateral fastening is sealed by this stress absorbing portion 63 c. By absorbing a part of this, it is possible to prevent stress concentration on the explosion-proof thin portion 63a at the time of lateral fastening. Thereby, it can suppress that the working pressure of a safety valve fluctuates, and the reliability of a safety valve can be improved only that much.

次に、封口体６の連結部６３におけるボス部６１側の付け根部分に、これを取り囲んでいる直ぐ外側の部分（第１肉厚部分）６３ｂに比べて肉厚が不連続に薄くなるように且つ前記第１肉厚部分６３ｂとの間に段差を有するように形成された防爆用の薄肉部分６３ａを設けたことにより、短絡高温時や過放電放置時において当該薄肉部分６３ａが確実に剪断されるようになる。すなわち、短絡時の発熱による封口体樹脂の軟化と電池内圧の上昇とにより連結部６３の変形が起きる場合には、防爆用の薄肉部分６３ａに応力が集中することにより、連結部６３のドーム状変形による負極端子板７への接触が起こる前に薄肉部分６３ａが剪断破壊されて内圧が開放される。また、過放電放置時には発熱による封口体樹脂の軟化は生じないが、内圧の上昇により連結部６３に応力が作用するから、この場合も上記の薄肉部分６３ａへの応力集中により、連結部６３の破断が起こる前に薄肉部分６３ａが剪断破壊されて内圧が開放される。こうして短絡高温時や過放電放置時に安全弁が正常の作動することにより、封口体６の連結部６３が破裂することなく内圧が開放されるから、連結部６３の破裂により生じる内容物の飛散や破裂音の発生を防止することができる。 Next, the base portion of the connecting portion 63 of the sealing body 6 on the boss portion 61 side is discontinuously thinner than the immediately outer portion (first thick portion) 63b surrounding it. Further, by providing the explosion-proof thin portion 63a formed to have a step between the first thick portion 63b, the thin portion 63a is reliably sheared at the time of short-circuit high temperature or overdischarge. Become so. That is, when deformation of the connecting portion 63 occurs due to softening of the sealing body resin due to heat generation at the time of short circuit and an increase in battery internal pressure, stress concentrates on the explosion-proof thin-walled portion 63a, so that the dome shape of the connecting portion 63 is obtained. Before contact with the negative electrode terminal plate 7 due to deformation occurs, the thin-walled portion 63a is sheared and broken to release the internal pressure. Further, although the sealing body resin is not softened due to heat generation when left overdischarged, stress is applied to the connecting portion 63 due to an increase in internal pressure. In this case, the stress concentration on the thin portion 63a also causes the connection portion 63 to Before the breakage occurs, the thin portion 63a is sheared and the internal pressure is released. In this way, when the safety valve operates normally during short-circuit high temperature or overdischarge, the internal pressure is released without rupturing the connecting portion 63 of the sealing body 6, so that the contents scattered or ruptured due to the rupture of the connecting portion 63 can be obtained. Generation of sound can be prevented.

特に、封口体６の連結部６３における第１肉厚部分６３ｂから第２肉厚部分６３ｄに至る部分を、前者から後者に行くに従って肉厚が連続的に厚くなるように形成し、第１肉厚部分６３ｂの肉厚を0.４〜0.５mm、第２肉圧部分６３ｄの肉厚を第１肉厚部分６３ｂの肉厚の2.５〜3.０倍とした場合には、このような連結部６３の厚肉形状と、第１肉厚部分６３ｂとの間に所定の段差を有する防爆用の薄肉部分６３ａの構造とが相まって、高温短絡時や過放電放置時における封口体６の破裂を確実に防止することが可能となる。 In particular, a portion from the first thick portion 63b to the second thick portion 63d in the connecting portion 63 of the sealing body 6 is formed such that the thickness continuously increases from the former to the latter, When the thickness of the thick portion 63b is 0.4 to 0.5 mm and the thickness of the second pressure portion 63d is 2.5 to 3.0 times the thickness of the first thickness portion 63b, this Such a thick shape of the connecting portion 63 and the structure of the explosion-proof thin portion 63a having a predetermined level difference between the first thick portion 63b and the sealing body 6 at the time of high-temperature short circuit or overdischarge It is possible to reliably prevent the rupture.

図１は、本発明を単三形アルカリ乾電池（以下、単にアルカリ乾電池または電池ともいう）に適用した例を示したものである。このアルカリ乾電池は、正極端子を兼ねる有底円筒状の外装缶１と、この外装缶１内（セル室Ｃ内）に収容された円筒状の正極２と、この正極２の中空部内に配置されたコップ状の不織布からなるセパレータ３と、このセパレータ３内に充填されたペースト状の負極４と、この負極４内に挿入された釘状の負極集電棒（負極集電体）５と、セパレータ３および正極２に含浸された水酸化カリウム水溶液を主成分とする電解液（図示せず）とを有し、外装缶１の開口端部１ａ側を封口した構成である。外装缶１の底部には、凸状の正極端子部分１ｂが形成されている。ここで、図１中の符号Ａは外装缶１の封口部分を示し、符号Ｂは外装缶１の胴部分を示す。さらに詳しくは、図１に示した状態において、外装缶１の封口部分Ａとは、グルーブによる変形で外装缶１の外形がもとの寸法より小さくなる部分から上の部分を指し、胴部分Ｂとはそれより下の部分を指す。 FIG. 1 shows an example in which the present invention is applied to an AA alkaline battery (hereinafter also simply referred to as an alkaline battery or a battery). The alkaline dry battery is arranged in a bottomed cylindrical outer can 1 that also serves as a positive electrode terminal, a cylindrical positive electrode 2 accommodated in the outer can 1 (in the cell chamber C), and a hollow portion of the positive electrode 2. A separator 3 made of a cup-shaped non-woven fabric, a paste-like negative electrode 4 filled in the separator 3, a nail-shaped negative electrode current collector rod (negative electrode current collector) 5 inserted into the negative electrode 4, a separator 3 and an electrolytic solution (not shown) mainly composed of an aqueous potassium hydroxide solution impregnated in the positive electrode 2, and the opening end 1 a side of the outer can 1 is sealed. A convex positive terminal portion 1 b is formed on the bottom of the outer can 1. Here, symbol A in FIG. 1 indicates a sealing portion of the outer can 1, and symbol B indicates a body portion of the outer can 1. More specifically, in the state shown in FIG. 1, the sealing portion A of the outer can 1 refers to a portion above the portion where the outer shape of the outer can 1 becomes smaller than the original dimension due to deformation by the groove, and the body portion B Refers to the part below it.

そして、本発明を適用した上記のアルカリ乾電池においては、外装缶の胴部分Ａにおける缶厚み（肉厚）が0.１８mm以下とされ、かつ封止部分Ｂにおける缶厚みが胴部分Ａにおける缶厚みの1.４倍以上に設定されている。 In the alkaline dry battery to which the present invention is applied, the can thickness (wall thickness) in the barrel portion A of the outer can is 0.18 mm or less, and the can thickness in the sealed portion B is the can thickness in the barrel portion A. Is set to 1.4 times or more.

外装缶１内に収容された円筒状の正極２は、二酸化マンガンと黒鉛（導電材料）との混合物で構成されている。上記のアルカリ乾電池においては、この二酸化マンガンと黒鉛（導電材料）とを混合して正極２を成形する際に、水酸化カリウム濃度を高めたアルカリ電解液が用いられている。これは、水酸化カリウム濃度を高めたアルカリ電解液を用いて正極２を成形することで、正極２となる成形体の強度を高めることができるからである。その結果、二酸化マンガンや黒鉛（導電材料）を結合するためのバインダー（結合剤樹脂）を使用する必要がなくなり、その分だけ放電特性に関係する材料の充填率を高めることができるので、電池の放電特性が改善されることとなる。また、外装缶１内に収容された正極２の強度が高まることで、外装缶１に上記のような肉厚の薄い鋼板を使用した場合であっても外力による変形を受けにくくなる。 The cylindrical positive electrode 2 accommodated in the outer can 1 is composed of a mixture of manganese dioxide and graphite (conductive material). In the alkaline dry battery described above, an alkaline electrolyte with an increased potassium hydroxide concentration is used when the positive electrode 2 is formed by mixing manganese dioxide and graphite (conductive material). This is because the strength of the molded body to be the positive electrode 2 can be increased by molding the positive electrode 2 using an alkaline electrolyte with an increased potassium hydroxide concentration. As a result, it is not necessary to use a binder (binder resin) for bonding manganese dioxide or graphite (conductive material), and the filling rate of the material related to the discharge characteristics can be increased accordingly, so that The discharge characteristics will be improved. In addition, since the strength of the positive electrode 2 accommodated in the outer can 1 is increased, even when a thin steel plate as described above is used for the outer can 1, it becomes difficult to be deformed by an external force.

外装缶１の開口端部１ａ内、すなわち封口部分Ａ内には、防爆用の安全弁機構を有する例えばポリアミドやポリプロピレン等の樹脂（図示例では６，６ナイロン）からなる封口体６と、これを内周から支える支持手段であり且つ負極端子板を兼ねた一枚の金属板７（負極端子板７）と、外装缶１の開口端部１ａと負極端子板７との間を電気的に絶縁する鍔付き短筒状の樹脂体からなる絶縁板８とが装着されている。 In the opening end 1a of the outer can 1, that is, in the sealing portion A, a sealing body 6 made of a resin such as polyamide or polypropylene (6, 6 nylon in the illustrated example) having an explosion-proof safety valve mechanism is provided. Electrically insulated between one metal plate 7 (negative electrode terminal plate 7) which is a supporting means supported from the inner periphery and also serves as a negative electrode terminal plate, and the open end 1a of the outer can 1 and the negative electrode terminal plate 7 An insulating plate 8 made of a short tubular resin body with a flange is attached.

封口体６は、図２に拡大して示すように、負極集電棒５が挿通される孔６１ａを有するボス部６１と、外装缶１の内周面と接する外周部６２と、ボス部６１と外周部６２とを連結し且つ前者から後者に至る面を封鎖する連結部６３とで構成されている。そして、この封口体６によって、電池活物質の収容されているセル室Ｃを閉じてセル室Ｃ内の電解液の外部への漏出を防止し、かつ負極端子板７と外装缶１との間を前記の絶縁板８とともに電気的に絶縁するようになっている。 As shown in an enlarged view in FIG. 2, the sealing body 6 includes a boss portion 61 having a hole 61 a through which the negative electrode current collecting rod 5 is inserted, an outer peripheral portion 62 in contact with the inner peripheral surface of the outer can 1, and a boss portion 61. It is comprised by the connection part 63 which connects the outer peripheral part 62 and seals the surface from the former to the latter. The sealing body 6 closes the cell chamber C in which the battery active material is accommodated to prevent leakage of the electrolyte in the cell chamber C to the outside, and between the negative electrode terminal plate 7 and the outer can 1. Are electrically insulated together with the insulating plate 8.

封口体６の連結部６３におけるボス部６１側の付け根部分には、防爆用の安全弁機構を構成する薄肉部分６３ａが設けられている。この薄肉部分６３ａは、電池の内圧が所定レベル以上に上昇したときに連結部６３が図中の上方側に変形し、さらに内圧が上昇したときに当該薄肉部分６３ａが破断することにより、内圧の一部を負極端子板７の後述するガス抜き孔を介してセル室Ｃ外に開放する機能を果たすものである。ところが、従来の封口体では、防爆用の薄肉部分とこれの直ぐ外側の部分との間の肉厚があまり大きくなく、しかも連結部の肉厚が比較的薄く且つ一様であったために、高温短絡時に薄肉部分が破断する前にドーム状に膨張したまま負極端子板に接触してガス抜き孔を塞いでしまったり、過放電放置時に薄肉部分が剪断されるよりも前にドーム状に膨らんだ連結部が破裂したりする可能性が全くないとは言い切れなかった。そこで、このような問題が生じないようにするため、本発明のアルカリ乾電池に備えられた封口体６では、連結部６３に設けた防爆用の薄肉部分６３ａが、これを取り囲んでいる直ぐ外側の部分（第１肉厚部分）６３ｂに比べて肉厚が不連続に薄くなるように且つ第１肉厚部分６３ｂとの間に所定の段差を有するように形成されている。 A thin portion 63a that constitutes an explosion-proof safety valve mechanism is provided at the base portion of the connecting portion 63 of the sealing body 6 on the boss portion 61 side. When the internal pressure of the battery rises to a predetermined level or more, the thin portion 63a is deformed upward in the drawing, and when the internal pressure further rises, the thin portion 63a breaks, so that the internal pressure is reduced. A part of the negative electrode terminal plate 7 functions to be opened to the outside of the cell chamber C through a gas vent described later. However, in the conventional sealing body, the thickness between the explosion-proof thin portion and the portion immediately outside it is not so large, and the thickness of the connecting portion is relatively thin and uniform. Before the thin-walled part breaks during a short circuit, it contacts the negative terminal plate while expanding in the dome shape, or closes the vent hole, or the thin-walled part swells before shearing when left overdischarged. It could not be said that there was no possibility that the connecting part would burst. Therefore, in order to prevent such a problem from occurring, in the sealing body 6 provided in the alkaline battery of the present invention, the explosion-proof thin-walled portion 63a provided in the connecting portion 63 is immediately outside the surrounding portion. Compared with the portion (first thick portion) 63b, the thickness is discontinuously reduced and a predetermined step is formed between the first thick portion 63b.

封口体６の連結部６３における外周部６２側の付け根部分には、比較的薄肉の応力吸収部６３ｃが設けられている。この応力吸収部６３ｃは、これの直ぐ内周側に位置する部分（第２肉厚部分）６３ｄに比べて肉厚が不連続に薄くなるように且つ第２肉厚部分６３ｄとの間に段差を有するように形成されている。これにより、外装缶１の開口端部１ａを封口すべく封口体６を締め付けたときに連結部６３に作用する応力の一部を吸収して、防爆用の薄肉部分６３ａへの応力集中を防止する。 A relatively thin-walled stress absorbing portion 63c is provided at the base portion of the connecting portion 63 of the sealing body 6 on the outer peripheral portion 62 side. The stress absorbing portion 63c has a step difference between the second thick portion 63d and the second thick portion 63d so that the thickness is discontinuously thin compared to the portion (second thick portion) 63d located immediately on the inner peripheral side thereof. It is formed to have. This absorbs a part of the stress acting on the connecting portion 63 when the sealing body 6 is tightened to seal the opening end 1a of the outer can 1 and prevents stress concentration on the explosion-proof thin portion 63a. To do.

封口体６の連結部６３における第１肉厚部分６３ｂから第２肉厚部分６３ｄに至る部分は、第１肉厚部分６３ｂから第２肉厚部分６３ｄに行くに従って肉厚が連続的に厚くなるように形成されている。図示例の封口体６では、第１肉厚部分６３ｂの肉厚は0.４〜0.５mmであり、第２肉圧部分６３ｄの肉厚は第１肉厚部分６３ｂの肉厚の2.５〜3.０倍とされている。そして、このような連結部６３の形状と、従来のものと比べた場合の連結部６３の厚肉化と、第１肉厚部分６３ｂとの間に所定の段差を有する防爆用の薄肉部分６３ａの構造とが相まって、上述した高温短絡時や過放電放置時における不具合をさらに確実に防止できるようになっている。 The thickness of the connecting portion 63 of the sealing body 6 from the first thick portion 63b to the second thick portion 63d continuously increases from the first thick portion 63b to the second thick portion 63d. It is formed as follows. In the sealing body 6 in the illustrated example, the thickness of the first thick portion 63b is 0.4 to 0.5 mm, and the thickness of the second thick pressure portion 63d is 2 of the thickness of the first thick portion 63b. 5 to 3.0 times. The shape of the connecting portion 63, the thickness of the connecting portion 63 compared to the conventional one, and the explosion-proof thin portion 63a having a predetermined step between the first thick portion 63b. In combination with this structure, it is possible to more reliably prevent the above-described problems during high-temperature short-circuiting or overdischarge.

封口体６のボス部６１においては、負極集電棒５が挿通された孔６１ａの図２中の上端部分が、これ以外の孔部分の内径よりも大きな内径を有する大径孔部分６１ｂとされており、負極集電棒５を挿通セットした図示状態において負極集電棒５の大径端部５ａがボス部６１の大径孔部分６１ｂに嵌合して、当該大径端部５ａの上端がボス部６１の上端面から僅かに突出した状態またはそれと略面一の状態となっている。図２においてボス部６１の周壁部分は外周部６２のそれに比べて肉厚が厚くされているが、これは、封口時に外周部６２がかしめられて変形する部分であるのに対し、ボス部６１はこれに挿通された負極集電棒５とともに負極端子板７の中央部分の裏面側にあってこの部分が外力によって内側にへこんだりしないように負極端子板７を裏面側から支える役目をも持っているからである。 In the boss portion 61 of the sealing body 6, the upper end portion in FIG. 2 of the hole 61a through which the negative electrode current collecting rod 5 is inserted is a large-diameter hole portion 61b having an inner diameter larger than the inner diameter of the other hole portions. In the illustrated state in which the negative electrode current collector rod 5 is inserted and set, the large diameter end portion 5a of the negative electrode current collector rod 5 is fitted into the large diameter hole portion 61b of the boss portion 61, and the upper end of the large diameter end portion 5a is the boss portion. It is in a state of slightly protruding from the upper end surface of 61 or substantially flush with it. In FIG. 2, the peripheral wall portion of the boss portion 61 is thicker than that of the outer peripheral portion 62. This is a portion where the outer peripheral portion 62 is caulked and deformed at the time of sealing, whereas the boss portion 61. Is on the back side of the central portion of the negative electrode terminal plate 7 together with the negative electrode current collector rod 5 inserted therethrough, and also has a function of supporting the negative electrode terminal plate 7 from the back side so that this portion is not dented inward by an external force. Because.

一方、負極端子板７は、一枚の鋼板で構成されており、図３および図４に単体で示すように、凸状に形成された中央部の端子面７７と、この端子面７７を垂直に貫く方向から見て端子面７７を取り囲むように形成された外周部の鍔面７８と、端子面７７の外周から鍔面７８の内周に至る円筒状の端子面側面７９とからなる。このうち端子面７７には、これの中心部を取り囲むように僅かに凹んだ平面視で円形の凹み７７ａが形成されており、この凹み７７ａが取り囲んでいる中央部分の裏面側に負極集電棒５の大径端部５ａがスポット溶接等により接合されている（図２参照）。 On the other hand, the negative electrode terminal plate 7 is composed of a single steel plate. As shown in FIG. 3 and FIG. 4 alone, the negative terminal plate 7 has a central terminal surface 77 formed in a convex shape, and the terminal surface 77 is vertical. And the cylindrical terminal surface side surface 79 extending from the outer periphery of the terminal surface 77 to the inner periphery of the flange surface 78. Among these, the terminal surface 77 is formed with a circular recess 77a in a plan view slightly recessed so as to surround the central portion of the terminal surface 77, and the negative electrode current collector rod 5 is formed on the back side of the central portion surrounded by the recess 77a. Are joined by spot welding or the like (see FIG. 2).

負極端子板７における鍔面７８は、内周側の平坦部７８ａと、封口体６をかしめる際にこれの外周部６２を内周からしっかりと支える目的で当該負極端子板７の全周にわたって設けられた外周側の湾曲部７８ｂとからなる。内周側の平坦部７８ａは、図４に示した厚み方向の断面において、外周側の湾曲部７８ｂに比べて相対的に平坦な形状を有する。そして、この平坦部７８ａが端子面７７ａに対して、外側に下る方向に４度以上傾斜した構造とされていることにより、封口工程での負極端子板７の変形による高さ方向寸法のばらつきを低減させるようになっている。なお、図示例は、鍔面平坦部７８ａと端子面７７とのなす角度α、すなわち鍔面平坦部７８ａの外周端（湾曲部７８ｂ側）にある変曲点と内周端（端子面側面側７９側）にある変曲点とを結ぶ平面と、端子面７７とのなす角度αを８度としたものである。 The flange surface 78 of the negative electrode terminal plate 7 covers the entire circumference of the negative electrode terminal plate 7 in order to firmly support the outer peripheral portion 62 from the inner periphery when the inner peripheral flat portion 78a and the sealing body 6 are caulked. It comprises an outer peripheral curved portion 78b provided. The flat part 78a on the inner peripheral side has a relatively flat shape as compared with the curved part 78b on the outer peripheral side in the cross section in the thickness direction shown in FIG. The flat portion 78a is inclined by 4 degrees or more in the downward direction with respect to the terminal surface 77a, so that variations in the height direction dimension due to deformation of the negative electrode terminal plate 7 in the sealing step can be prevented. It is intended to reduce. In the illustrated example, the angle α formed between the flange flat portion 78a and the terminal surface 77, that is, the inflection point and the inner peripheral end (terminal surface side surface side) at the outer peripheral end (curved portion 78b side) of the flange flat portion 78a. The angle α formed between the plane connecting the inflection point on the (79 side) and the terminal surface 77 is 8 degrees.

負極端子板７の外周側に設けられた湾曲部７８ｂは、負極端子板７をこれの中心を通って厚み方向に切断したときの断面において、平均曲率半径が１mm以下で、かつ９０度より大きい角度範囲にわたってほぼＣ字状または弧状に湾曲形成されており、しかもその外周側が、すでに説明した意味において９０度より大きい角度範囲にわたって封口体６の外周部６２の内周側と接触している。そして、この接触部分において封口体６の外周部６２が、これの内周側に位置する負極端子板７の湾曲部７８ｂと、外周側に位置する外装缶１の開口端部１ａとでかしめられて締め付けられていることにより、図２に示したように封口体６が外装缶１の開口端部１ａ内の所定位置に装着され、この状態でセル室Ｃ内の上方が封口されるとともに、封口体６の連結部６３と負極端子板７との間に安全弁（薄肉部分６３ａ）の動作を確保するための所要の空間が形成された構造となっている。なお、図３および図４中の符号７ｆはセル室内で発生したガスを安全弁の作動時に外部に逃がすためのガス抜き孔を示す。 The curved portion 78b provided on the outer peripheral side of the negative electrode terminal plate 7 has an average radius of curvature of 1 mm or less and greater than 90 degrees in a cross section when the negative electrode terminal plate 7 is cut in the thickness direction through the center thereof. It is curved in a substantially C shape or arc shape over the angular range, and its outer peripheral side is in contact with the inner peripheral side of the outer peripheral portion 62 of the sealing body 6 over the angular range larger than 90 degrees in the already described meaning. And in this contact part, the outer peripheral part 62 of the sealing body 6 is caulked with the curved part 78b of the negative electrode terminal board 7 located in the inner peripheral side of this, and the opening end part 1a of the exterior can 1 located in the outer peripheral side. As shown in FIG. 2, the sealing body 6 is mounted at a predetermined position in the opening end 1a of the outer can 1, and in this state, the upper portion in the cell chamber C is sealed, A required space for ensuring the operation of the safety valve (thin wall portion 63a) is formed between the connecting portion 63 of the sealing body 6 and the negative electrode terminal plate 7. 3 and 4 indicates a gas vent for releasing the gas generated in the cell chamber to the outside when the safety valve is operated.

なお、上記の湾曲部７８ｂが設けられている角度範囲とは、負極端子板７の他の例を示す図５に記載したように、湾曲部７８ｂを、上記の平均曲率半径ｒを半径として有する仮想的な円で近似したときに、この円の中心Ｏを基準として湾曲部７８ｂの両端がなす角度θ₁ を意味する。湾曲部７８ｂと封口体６とが接触している部分の角度範囲も同様に、湾曲部７８ｂを、上記の平均曲率半径ｒを半径として有する仮想的な円で近似したときに、この円の中心Ｏを基準として、封口体６と接触している湾曲部７８ｂの当該接触部分の両端がなす角度θ₂ を意味する。 Note that the angle range in which the curved portion 78b is provided means that the curved portion 78b has the average curvature radius r as a radius, as described in FIG. 5 showing another example of the negative electrode terminal plate 7. When approximated by a virtual circle, it means an angle θ ₁ formed by both ends of the curved portion 78b with reference to the center O of the circle. Similarly, when the curved portion 78b is approximated by a virtual circle having the average curvature radius r as a radius, the angular range of the portion where the curved portion 78b and the sealing body 6 are in contact is also the center of this circle. With reference to O, it means an angle θ ₂ formed by both ends of the contact portion of the curved portion 78b in contact with the sealing body 6.

一方、鍔付き短筒状の樹脂体からなる絶縁板８は、封口体６が装着された後に、負極端子板７の端子面７７と外装缶１の開口端および封口体６の外周部６２の一端との間に形成された隙間部分に、当該絶縁板８における短筒部分８ａを嵌め込むことで図示した所定位置に取り付けられており、これによって負極端子板７と外装缶１との間を電気的に絶縁している。 On the other hand, the insulating plate 8 made of a short-tubular resin body with a flange is attached to the terminal surface 77 of the negative electrode terminal plate 7, the open end of the outer can 1, and the outer peripheral portion 62 of the sealing body 6 after the sealing body 6 is mounted. The short cylindrical portion 8a of the insulating plate 8 is fitted into the gap portion formed between the one end and the predetermined position shown in the figure, so that the gap between the negative electrode terminal plate 7 and the outer can 1 is secured. It is electrically insulated.

なお、負極端子板（金属板）７の外周側に設ける湾曲部７８ｂは、先に述べた平均曲率半径ｒと角度範囲θ₁ ・θ₂ の条件を満たしてさえいれば、その曲げ方や曲げ方向は問わない。負極端子板７の端子面７ａと同じ方向もしくは同じ側に凸となるように湾曲部７８ｂを形成することができる（図５参照）。負極端子板７の半径方向の外方に向けて凸となるように湾曲部７８ｂを形成してもよい。負極端子板７の外周部を端子面７７の突出方向とは反対側の方向にいったん曲げ、そこからさらに逆向きに湾曲させて外周側が封口体６の外周部６２と所定状態で接するように湾曲部７８ｂを形成してもよい。また、負極端子板７には、例えば電池を落としたときや端子面７７を外部から強く押したときにも簡単にはへこまないようにしたり、封口体６のかしめ時に負極端子板７全体が変形しないようにしたりする目的で、中央部に設けた凹み７７ａと同じような凹凸を同心円状に設けてもよい。 The bending portion 78b provided on the outer peripheral side of the negative electrode terminal plate (metal plate) 7 can be bent or bent as long as it satisfies the conditions of the average curvature radius r and the angle ranges θ ₁ and θ ₂ described above. The direction is not important. The curved portion 78b can be formed so as to protrude in the same direction or the same side as the terminal surface 7a of the negative electrode terminal plate 7 (see FIG. 5). The curved portion 78b may be formed so as to protrude outward in the radial direction of the negative electrode terminal plate 7. The outer peripheral portion of the negative electrode terminal plate 7 is once bent in the direction opposite to the protruding direction of the terminal surface 77, and further bent in the opposite direction, so that the outer peripheral side contacts the outer peripheral portion 62 of the sealing body 6 in a predetermined state. The portion 78b may be formed. Further, the negative electrode terminal plate 7 is not easily dented even when the battery is dropped or the terminal surface 77 is strongly pressed from the outside, or the entire negative electrode terminal plate 7 is caulked when the sealing body 6 is caulked. For the purpose of preventing deformation, unevenness similar to the recess 77a provided in the central portion may be provided concentrically.

以下において本発明の実施例を説明するが、もちろん本発明はこれらの実施例に限定されるものではない。 Examples of the present invention will be described below. Of course, the present invention is not limited to these examples.

〈実施例〉
本発明に係る樹脂製封口体の効果を確認するために、単三形アルカリ電池に使用する樹脂製封口体について、以下の実験を行った。この実験では、実施例として図６に示すような６，６ナイロン製の封口体を使用し、比較例として図７に示すような６，６ナイロン製の封口体を使用した。これらの図に記載した肉厚寸法の単位はmmである。 <Example>
In order to confirm the effect of the resin sealant according to the present invention, the following experiment was conducted on the resin sealant used for the AA alkaline battery. In this experiment, a sealing body made of 6,6 nylon as shown in FIG. 6 was used as an example, and a sealing body made of 6,6 nylon as shown in FIG. 7 was used as a comparative example. The unit of the thickness dimension described in these figures is mm.

１．実験で使用した解析装置：
３ＤＣＡＤＰｒｏ−Ｅｎｇｉｎｅｅｒおよび構造解析ソフトＰｒｏ−Ｍｅｃｈａｎｉｃａ（日本パラメトリックテクノロジー社製）を使用した。 1. Analysis equipment used in the experiment:
3DCAD Pro-Engineer and structural analysis software Pro-Mechanica (manufactured by Japan Parametric Technology) were used.

２．実施条件：
座標軸はｒ（封口体の半径方向）、θ（封口体の周方向）、ｚ（ボス部の軸方向）の極座標を使用した。
（１）拘束条件（図８参照）；
負極集電棒の圧入を考慮し、封口体ボス部の内径をｒ外方向に0.０５mm強制変位させた。
スピニング封口時の横締めを考慮し、封口体外径をｒ内方向に0.１９mm強制変位させた。
封口体ボス部上面はｚ方向固定、ｒ方向・θ方向フリーとした。
負極端子板との接触部面はｚ方向固定、ｒ方向・θ方向フリーとした。
（２）荷重条件；
封口体下面を6.５ＭＰａ、7.０ＭＰａ、7.５ＭＰａで全面押圧した。
（３）温度条件；
常温（２３℃）および高温（１５０℃）でそれぞれ測定した。
（４）寸法パラメータ；
図８に示したＤ部段差寸法（第１肉厚部分の肉厚）については、それぞれ0.２５mm、0.３５mm、0.４５mmであるものを用意し、いずれが最適形状であるかを検討した。 2. Implementation conditions:
As coordinate axes, polar coordinates of r (radial direction of the sealing body), θ (circumferential direction of the sealing body), and z (axial direction of the boss portion) were used.
(1) Restraint conditions (see Fig. 8);
Considering the press-fitting of the negative electrode current collector rod, the inner diameter of the sealing body boss was forcibly displaced by 0.05 mm in the r direction.
Considering lateral tightening at the time of spinning sealing, the outer diameter of the sealing body was forcibly displaced by 0.19 mm in the r inner direction.
The upper surface of the sealing body boss was fixed in the z direction and free in the r and θ directions.
The contact surface with the negative electrode terminal plate was fixed in the z direction and free in the r and θ directions.
(2) Load conditions;
The entire bottom surface of the sealing body was pressed at 6.5 MPa, 7.0 MPa, and 7.5 MPa.
(3) Temperature conditions;
It measured at normal temperature (23 degreeC) and high temperature (150 degreeC), respectively.
(4) Dimension parameters;
For D part step size (thickness of the first thick part) shown in Fig. 8, we prepared 0.25mm, 0.35mm and 0.45mm respectively, and examined which is the optimal shape did.

３．測定および結果
電池内圧が上昇し、連結部の薄肉部分が破断する直前の変位および応力分布を調べた。その結果、以下のことが分かった。
（１）スピニング封口を考慮した場合の横締め時の変位・応力分布
変位；
実施例および比較例のいずれの封口体においても、最大変位は連結部における外周部側で起こっていた。
応力；
実施例の封口体では、連結部における外周部側の付け根部分に設けた応力吸収部で応力集中が起こっており、連結部には顕著な応力分布が見られなかった。これに対して比較例の封口体では逆に顕著な応力集中は無く、連結部全体で応力を受け、連結部が全体的に変形しているのが見られた。また、応力吸収部を設けなかった比較例の封口体では、連結部におけるボス部側の付け根部分に設けた防爆用の薄肉部分に応力が集中することが確認された。 3. Measurement and Results The displacement and stress distribution immediately before the battery internal pressure increased and the thin portion of the connecting portion broke were examined. As a result, the following was found.
(1) Displacement and stress distribution during lateral tightening considering spinning sealing Displacement;
In any of the sealing bodies of Examples and Comparative Examples, the maximum displacement occurred on the outer peripheral side of the connecting portion.
stress;
In the sealing body of the example, stress concentration occurred in the stress absorbing portion provided at the base portion on the outer peripheral portion side in the connecting portion, and no significant stress distribution was observed in the connecting portion. On the other hand, in the sealing body of the comparative example, on the contrary, there was no significant stress concentration, and it was found that the connecting portion was subjected to stress and the connecting portion was deformed as a whole. Moreover, in the sealing body of the comparative example which did not provide a stress absorption part, it was confirmed that stress concentrates on the thin part for explosion prevention provided in the base part by the side of the boss | hub part in a connection part.

（２）常温（２３℃）にて内圧6.５ＭＰａ作用時の変位・応力分布
変位；
実施例の封口体では連結部中央から更にボス部側に最大変位0.２４mmが起こり、比較例の封口体では連結部のほぼ中央に最大変位0.４８mmが起こった。
応力；
実施例および比較例とも最大応力は連結部における防爆用の薄肉部分に起こっていた。比較例の封口体では、連結部の上面に設けられたリブの付け根部分にも応力が分散する傾向があった。 (2) Displacement and stress distribution when the internal pressure is 6.5 MPa at normal temperature (23 ° C) Displacement;
In the sealing body of the example, a maximum displacement of 0.24 mm occurred further from the center of the connecting portion toward the boss portion side, and in the sealing body of the comparative example, a maximum displacement of 0.48 mm occurred approximately at the center of the connecting portion.
stress;
In both the example and the comparative example, the maximum stress occurred in the thin-walled portion for explosion protection at the connecting portion. In the sealing body of the comparative example, there was a tendency that the stress was also distributed to the base portion of the rib provided on the upper surface of the connecting portion.

（３）高温（１５０℃）にて内圧6.５ＭＰａ作用時の変位・応力分布
変位；
常温時と同様、実施例の封口体では連結部中央から更にボス部側に最大変位0.９１mmが起こり、比較例の封口体では連結部のほぼ中央に最大変位1.９０mmが起こった。
応力；
実施例および比較例とも最大応力は連結部における防爆用の薄肉部分に起こっていた。比較例の封口体では、連結部の上面に設けられたリブの付け根部分にも応力が分散し、さらにくびれ形状に変形する傾向があった。 (3) Displacement and stress distribution when the internal pressure is 6.5 MPa at high temperature (150 ° C) Displacement;
Similar to the normal temperature, in the sealing body of the example, a maximum displacement of 0.91 mm occurred from the center of the connecting portion to the boss portion side, and in the sealing body of the comparative example, a maximum displacement of 1.90 mm occurred in the approximate center of the connecting portion.
stress;
In both the example and the comparative example, the maximum stress occurred in the thin-walled portion for explosion protection at the connecting portion. In the sealing body of the comparative example, the stress was also distributed to the base portion of the rib provided on the upper surface of the connecting portion, and further, there was a tendency to deform into a constricted shape.

（４）内圧上昇（安全弁作動圧増加）と連結部最大変位との関係
比較例の封口体では、安全弁作動圧最大6.５ＭＰａにおいて高温時連結部最大変位が1.９mmとなった。これに対し、実施例の封口体では、内圧（安全弁作動圧）を7.５ＭＰａまで増加しても連結部最大変位が1.１３mmであり、高温時においても負極端子板との接触を回避防止できることが確認された。 (4) Relationship between increase in internal pressure (increase in safety valve operating pressure) and maximum displacement of the connecting portion In the sealing body of the comparative example, the maximum displacement of the connecting portion at high temperature was 1.9 mm at a maximum safety valve operating pressure of 6.5 MPa. On the other hand, in the sealing body of the example, even when the internal pressure (safety valve operating pressure) is increased to 7.5 MPa, the maximum displacement of the connecting portion is 1.13 mm, preventing contact with the negative electrode terminal plate even at high temperatures. It was confirmed that it was possible.

（５）第１肉厚部分の肉厚と変位の関係
内圧（最大安全弁作動圧）設定に依存することであるが、高温時に負極端子板との接触を防止ために連結部の最大変位を1.２mm以下にするには、第１肉厚部分の肉厚を0.４５mmとする必要があることが確認できた。 (5) Relationship between wall thickness and displacement of the 1st wall thickness Although it depends on the setting of internal pressure (maximum safety valve operating pressure), the maximum displacement of the connecting part should be set to 1 to prevent contact with the negative electrode terminal plate at high temperatures. It was confirmed that the thickness of the first thickness portion needs to be 0.45 mm in order to make it less than 0.2 mm.

４．評価
以上の結果から次のような評価を行うことができる。
（１）スピニング封口を考慮した場合の横締め時の変位・応力分布に関して
実施例の封口体では連結部に横締めによる応力を吸収する応力吸収部を設けたので、防爆用の薄肉部分への負担を軽減することができる。 4). Evaluation From the above results, the following evaluation can be performed.
(1) Displacement / stress distribution at the time of lateral fastening when considering a spinning seal Since the sealing body of the example is provided with a stress absorbing part that absorbs the stress caused by lateral fastening at the connecting part, The burden can be reduced.

（２）内圧6.５ＭＰａ作用時の変位・応力分布に関して
常温時（２３℃）においては、実施例および比較例のいずれの封口体も安全弁が作動できる変位量である（封口体の連結部が負極端子板に接触するまでの変位量は1.２mm）。しかし、高温時（１５０℃）においては、比較例の封口体で連結部の最大変位量が1.９mmであり、安全弁が作動する前に封口体が負極端子板に接触する。また、連結部のくびれ形状から、連結部の肉厚の薄さにより伸びが生じると考えられる。これらの点から、高温時に安全弁が作動せず、封口体がドーム状になるものが存在すると考えられる。これに対して実施例の封口体では、連結部の最大変位量が0.９１mmであり、封口体が負極端子板に接触する前に安全弁が作動すると推定できる。 (2) Displacement / stress distribution when the internal pressure is 6.5 MPa At normal temperature (23 ° C.), the sealing bodies of both the examples and the comparative examples have a displacement amount at which the safety valve can operate (the connecting portion of the sealing body is The displacement until it contacts the negative terminal plate is 1.2mm). However, at a high temperature (150 ° C.), the maximum displacement of the connecting portion of the sealing body of the comparative example is 1.9 mm, and the sealing body contacts the negative electrode terminal plate before the safety valve operates. Moreover, it is thought that elongation arises from the thin shape of a connection part from the constriction shape of a connection part. From these points, it is considered that the safety valve does not operate at a high temperature and the sealing body has a dome shape. On the other hand, in the sealing body of the example, the maximum displacement amount of the connecting portion is 0.91 mm, and it can be estimated that the safety valve operates before the sealing body contacts the negative electrode terminal plate.

（３）過放電放置時の封口体陥没破断に関して
過放電放置時の封口体陥没破断の主要因として、封口体連結部の薄肉と薄肉に伴う連結部の変形量が大きい点が挙げられるが、上記の実験結果から、比較例に比べて連結部を厚肉化した実施例の封口体によれば連結部の変形量を減少させることができる。また、連結部の内部応力について実施例の封口体と比較例の封口体とを比較すると、実施例の封口体では比較例の封口体の約６０％の内部応力に抑えることができる。したがって、実施例の封口体では、このような連結部の内部応力の低減によっても過放電放置時の封口体破断を解消することができる。 (3) Regarding the collapse of the sealing body when it is left overdischarged As a main factor of the collapsed breakage of the sealing body when it is left as it is overdischarged, there is a large amount of deformation of the connecting part due to the thinness of the sealing body connecting part, From the above experimental results, the amount of deformation of the connecting portion can be reduced according to the sealing body of the embodiment in which the connecting portion is thicker than the comparative example. Moreover, when the sealing body of an Example and the sealing body of a comparative example are compared about the internal stress of a connection part, in the sealing body of an Example, it can suppress to about 60% of internal stress of the sealing body of a comparative example. Therefore, in the sealing body of the embodiment, it is possible to eliminate the breakage of the sealing body when left overdischarged even by reducing the internal stress of the connecting portion.

（４）安全弁作動圧の改善および封口体の形状に関して
上記の実験では封口体連結部の変位・応力分布は主に連結部の肉厚に依存すると考え、Ｄ部段差寸法（第１肉厚部分の肉厚）をパラメータとして解析を行った。封口体連結部が負極端子板に接触するまでの変位量が1.２mmであることを考慮すると、安全弁作動圧が最大6.５ＭＰａである現行封口体（比較例）の仕様ではＤ部段差寸法を0.３５mmまで薄くすることができるが、安全弁作動圧最大設定値を7.０ＭＰａにすることは不可能である。安全弁作動圧最大設定値を改善するには、実施例の封口体におけるようにＤ部段差寸法を0.４５mmにする必要がある。 (4) Regarding improvement of safety valve operating pressure and shape of sealing body In the above experiment, it is considered that the displacement / stress distribution of the sealing body connecting part mainly depends on the thickness of the connecting part, and the D part step size (first thickness part) The thickness was measured as a parameter. Considering that the displacement until the sealing body connecting part contacts the negative electrode terminal plate is 1.2 mm, the current sealing body (comparative example) specification with a maximum safety valve operating pressure is 6.5 MPa. Can be reduced to 0.35 mm, but it is impossible to set the maximum safety valve operating pressure setting to 7.0 MPa. In order to improve the safety valve operating pressure maximum set value, it is necessary to set the D part step size to 0.45 mm as in the sealing body of the embodiment.

以上のように、本発明によれば、樹脂製封口体を備えたアルカリ乾電池において、横締め封口時に封口体における防爆用の薄肉部分への応力集中を回避することができ、薄肉部分の負担を軽減することができる。 As described above, according to the present invention, in an alkaline battery provided with a resin sealing body, it is possible to avoid stress concentration on the thin-walled portion for explosion-proofing in the sealing body during side-sealing sealing, and the burden on the thin-walled part can be avoided. Can be reduced.

また、本発明によれば、樹脂製封口体を備えたアルカリ乾電池において、封口体の破裂、これに伴う内容物の飛散および大きな破裂音の発生、封口体によるガス抜き孔の閉塞を防止でき、安全弁の信頼性、ひいては安全性を高めることができる。 Further, according to the present invention, in the alkaline dry battery provided with the resin sealing body, it is possible to prevent the sealing body from rupturing, the content scattering and the generation of a large burst sound, the blockage of the gas vent hole by the sealing body, The reliability of the safety valve, and thus the safety can be improved.

本発明を適用したアルカリ乾電池の全体構造を示す断面図である。It is sectional drawing which shows the whole structure of the alkaline dry battery to which this invention is applied. 図１の単三形アルカリ乾電池の封口部分を拡大して示す部分拡大図である。It is the elements on larger scale which expand and show the sealing part of the AA alkaline battery of FIG. 本発明で用いられる負極端子板（金属板）の一例を示す平面図である。It is a top view which shows an example of the negative electrode terminal plate (metal plate) used by this invention. 図３の負極端子板の断面構造を示す縦断面図である。It is a longitudinal cross-sectional view which shows the cross-section of the negative electrode terminal plate of FIG. 負極端子板の他の一例を示すもので、その周辺部分の構造を一部省略および簡略化して示す断面図である。FIG. 10 is a cross-sectional view showing another example of the negative electrode terminal plate, partially omitting and simplifying the structure of the peripheral portion thereof. 本発明の実施例で用いた樹脂製封口体の構造を示す縦断面図である。It is a longitudinal cross-sectional view which shows the structure of the resin-made sealing body used in the Example of this invention. 比較例で用いた樹脂製封口体の構造を示す縦断面図である。It is a longitudinal cross-sectional view which shows the structure of the resin-made sealing bodies used by the comparative example. 本発明の実施例において行った実験条件を記載した説明図である。It is explanatory drawing which described the experimental condition performed in the Example of this invention. 従来のアルカリ乾電池（単三形アルカリ乾電池）の一般的な構造を示す断面図である。It is sectional drawing which shows the general structure of the conventional alkaline battery (AA alkaline battery). 図９のアルカリ乾電池における封口部分を拡大して示す部分拡大図である。It is the elements on larger scale which expand and show the sealing part in the alkaline dry battery of FIG. 従来のアルカリ乾電池（単三形）において封口体の連結部が金属板（金属ワッシャ）のガス抜き孔を塞いだ状態を示す模式図である。It is a schematic diagram which shows the state which the connection part of the sealing body closed the gas vent hole of the metal plate (metal washer) in the conventional alkaline dry battery (AA size).

Explanation of symbols

１外装缶
１ａ外装缶の開口端部
２正極
３セパレータ
４負極
５集電棒
６樹脂製封口体
６１ボス部
６２外周部
６３連結部
６３ａ防爆用の薄肉部分
６３ｂ第１肉厚部分
６３ｃ応力吸収部
６３ｄ第２肉厚部分
７負極端子板（金属板、支持手段） DESCRIPTION OF SYMBOLS 1 Outer can 1a Open end 2 of outer can 2 Positive electrode 3 Separator 4 Negative electrode 5 Current collecting rod 6 Resin sealing body 61 Boss part 62 Outer peripheral part 63 Connection part 63a Explosion-proof thin part 63b First thick part 63c Stress absorption part 63d Second thick part 7 Negative terminal plate (metal plate, support means)

Claims

Inside the bottomed cylindrical outer can, the positive electrode and the negative electrode, the separator disposed between them, and the electrolytic solution are accommodated, and the resin sealing body and the inner periphery are disposed in the opening end of the outer can. An alkaline dry battery in which the opening end of the outer can is sealed by fastening the resin sealing body with the outer can and the supporting means.
As the support means, a single metal plate that also serves as a negative electrode terminal plate is used,
The resin sealing body includes a boss portion for holding a negative electrode current collector rod inserted into a central portion of the negative electrode, an outer peripheral portion that is supported from the inner periphery by the support means and is in contact with the inner peripheral surface of the outer can, and a boss portion. A connecting portion that connects the outer peripheral portion,
The connecting portion of the resin sealing body has an explosion-proof thin portion at the base portion on the boss portion side, and the opening end portion of the outer can is sealed at the base portion on the outer peripheral portion side. A stress absorbing part is provided that absorbs part of the stress acting on the connecting part so that stress does not concentrate on the explosion-proof thin part when the resin sealing body is tightened,
The stress absorbing portion is formed so as to have a step difference between the portion positioned on the inner peripheral side so that the thickness is discontinuously thin compared to the portion positioned immediately on the inner peripheral side thereof. An alkaline battery characterized in that

Inside the bottomed cylindrical outer can, the positive electrode and the negative electrode, the separator disposed between them, and the electrolytic solution are accommodated, and the resin sealing body and the inner periphery are disposed in the opening end of the outer can. An alkaline dry battery in which the opening end of the outer can is sealed by fastening the resin sealing body with the outer can and the supporting means.
As the support means, a single metal plate that also serves as a negative electrode terminal plate is used,
The resin sealing body includes a boss portion for holding a negative electrode current collector rod inserted into a central portion of the negative electrode, an outer peripheral portion that is supported from the inner periphery by the support means and is in contact with the inner peripheral surface of the outer can, and a boss portion. A connecting portion that connects the outer peripheral portion,
The connecting portion of the resin sealing body includes a first wall so that the thickness of the base portion on the boss portion side is discontinuously thin compared to the first thick portion on the outer side immediately surrounding the base portion. An explosion-proof thin-walled portion formed so as to have a step between the thick portion and a resin sealing body for sealing the opening end of the outer can at the base portion on the outer peripheral side is provided. A stress absorbing part is provided that absorbs part of the stress acting on the connecting part so that stress does not concentrate on the explosion-proof thin part when tightened,
The stress absorbing portion is formed so that the thickness is discontinuously thin compared to the second thick portion located immediately on the inner peripheral side of the stress absorbing portion and has a step between the second thick portion. And
The portion from the first thick portion to the second thick portion in the connecting portion is formed such that the thickness continuously increases from the first thick portion to the second thick portion. Alkaline battery.

The thickness of the first thickness portion is 0.4 to 0.5 mm, and the thickness of the second thickness portion is set to 2.5 to 3.0 times the thickness of the first thickness portion. The alkaline dry battery according to claim 2 .