JP3582306B2

JP3582306B2 - Manufacturing method of cylindrical battery

Info

Publication number: JP3582306B2
Application number: JP18337197A
Authority: JP
Inventors: 俊奈佐伯; 正弘中村
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 1997-07-09
Filing date: 1997-07-09
Publication date: 2004-10-27
Anticipated expiration: 2017-07-09
Also published as: JPH1131484A

Description

【０００１】
【発明の属する技術分野】
本発明は、円筒形電池の製造方法に関するものである。
【０００２】
【従来の技術】
従来の円筒形電池は、発電要素を充填した有底円筒状の電池ケースの開口部近傍を内側に突出させて環状の段部を形成し、絶縁パッキングを介して負極端子を兼ねる金属封口板を支えると共に、電池ケースの開口端部を内側に折り曲げることにより、前記絶縁パッキングを電池ケースの段部と折り曲げられたケースの開口端との間に狭持された金属封口板との間で上下方向に圧縮して封口する構造のものが知られている。
【０００３】
また、予め電池ケースの開口部を拡口して段部を形成し、絶縁パッキングを介して負極端子を兼ねる金属封口板を支えると共に、電池ケースの開口部を縮径することにより絶縁パッキングを電池の半径方向に圧縮すると共に、電池ケースの開口端を内側に折り曲げて金属封口板を支え、封口する円筒形電池の製造方法が開示されている。（例えば実公昭６１−３６０７０号公報）
【０００４】
【発明が解決しようとする課題】
しかしながら上記従来の技術の前者の構成方法では、絶縁パッキングは電池ケースの段部と折り曲げられたケースの開口端との間に狭持された金属封口板との間で上下方向の圧縮を受け、その反発弾性力により封口効果を得るようにしているため、絶縁パッキングの肉厚をあまり薄くできない。その結果、封口部の占める高さが大きくなり、発電要素の容積率が低下するという問題がある。また、上下方向の圧縮を強めるために電池ケースの開口端部の内側への折り曲げ度合いを大きくすると、電池ケースの開口端面が波打ち状に変形し外観的な問題とともに密封性も損なわれるという問題があった。
【０００５】
一方、後者の構成方法では、予め拡口した電池ケースの開口部を縮径すると、縮径された電池ケースの開口部内壁に上下方向に多数のしわが発生しやすく、そのしわに沿った微小な隙間を通じてクリーピング現象により電解液が漏出するという問題がある。
【０００６】
本発明は上記従来の問題点を解決するもので、密閉性が高く、耐漏液性が改善された円筒形電池の製造方法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】
この目的を達成するために本発明の円筒形電池の製造方法は、電池ケースの段部に載置した絶縁パッキングの外周縁鍔部を金属封口板と前記電池ケースで狭持し、電池ケースの段部に接する側の絶縁パッキングの外周縁のコーナー部を、電池ケースの段部とその上方の立ち上がり部に連なる曲率半径で形成された曲線上に配置して電池ケースの開口端部を内側に折り曲げて封口することを要旨とするものである。
【０００８】
この製造方法によって、電池ケースの開口端部を内側に折り曲げて封口した時に、電池ケースの段部と金属封口板に挟まれた部分の絶縁パッキングは、上下方向の圧縮を受けるとともに、前記段部とその上方の立ち上がり部に連なる曲率半径で形成された曲線上の最下点まで絶縁パッキングの底面が移動する際、絶縁パッキングの外周縁のコーナー部は曲率半径の半径方向にさらに圧縮される。
【０００９】
即ち、電池ケースの開口部を縮径せずに、電池ケースの開口端部を内側に折り曲げるための封口用カール金型の上下方向の移動により、電池ケースの段部と金属封口板に挟まれた部分の絶縁パッキングを上下方向と半径方向に同時に圧縮することができる。
【００１０】
また、封口用カール金型の上下方向の同じ移動条件において、従来の上下方向だけの絶縁パッキングの圧縮による封口方法よりも、特に密封性を確保するための要部である絶縁パッキングの外周縁のコーナー部の圧縮率が大きくなり電池の密封性が向上する。
【００１１】
【発明の実施の形態】
以下本発明の一実施例について、図面を参照しながら説明する。
【００１２】
図１は本発明の製造方法により作成した単１形アルカリ乾電池の一実施例を示す半裁断面図である。
【００１３】
図１において、１は正極端子を兼ねる電池ケースである。この電池ケース１内には、二酸化マンガンと黒鉛を主とする円筒状の正極合剤２が圧入されている。３は有底円筒状のセパレータで、その内部には亜鉛合金粉末をゲル状電解液に分散、混合した亜鉛負極４が充填されている。５は負極集電子、６は電池ケース１の開口部を閉塞する絶縁パッキングで、この絶縁パッキング６には、負極端子を兼ねる金属封口板７が負極集電子５の頭部に溶接されて配置され、この絶縁パッキング６が電池ケース１の開口部近傍を内側に突出させて形成した環状の段部８に載置されている。そして、電池ケース１の開口端部９を内側にかしめることにより封口されている。
【００１４】
次に本発明の製造方法である封口方法について具体的に説明する。
ニッケルメッキ鋼板を用い図２（ａ）に示した電池ケース１を作る。この電池ケース１の内部に、正極合剤２を圧入した後、溝入れローラーにより図２（ｂ）のように電池ケース１の開口部近傍に、内側に突出させた環状の段部８を形成した。なお、電池ケース１の段部８とその上方の立ち上がり部１０に連なる内面側を曲率半径で形成される曲線形状とした。
【００１５】
次いで電池ケースの段部８とその上方の立ち上がり部１０の内面側に封止剤１１を塗布し、セパレータ３、亜鉛負極４等の発電要素を図１に示すように配置した。
【００１６】
更に、図２（ｃ）に示すように、絶縁パッキング６の外周縁鍔部１２に金属封口板７を嵌合した状態で絶縁パッキング６を電池ケース１の段部８に載置した。この時、段部８に接する側の絶縁パッキング６の外周縁のコーナー部１３が、電池ケース１の曲率半径で形成される曲線部分の中央部に配置されるように絶縁パッキング６の寸法を設定した。
【００１７】
次に封口用カール金型の上下動によって、電池ケース１の開口端部９を内側に折り曲げて封口し、図１に示す単１形アルカリ乾電池（実施例）を作成した。
【００１８】
一方、段部８に接する側の絶縁パッキング６の外周縁のコーナー部１３が、電池ケース１の曲率半径で形成される曲線と水平に連なる段部８の変曲点の部分に配置されるように絶縁パッキング６の寸法を設定した。なお、絶縁パッキング６の外周縁鍔部１２の厚さと金属封口板７の嵌合度合いは実施例と同様にし、その他は実施例と同様の作り方で単１形アルカリ乾電池（比較例）を作成した。
【００１９】
次に上記実施例と比較例の電池を８０℃１２時間、−２０℃１２時間を１サイクルとするヒ−トショック試験を行った場合の漏液の発生率を（表１）に比較して示している。なお、試験数は各々１００個とし、サイクル数１０サイクルとした。
【００２０】
【表１】

【００２１】
この（表１）から明らかなように、比較例は漏液が発生しているが実施例は漏液が発生しておらず、耐漏液性が向上しているのがわかる。
【００２２】
封口用カール金型の上下方向の同じ移動条件において、即ち、封口高さ寸法が同じ条件の場合に、比較例の場合、図３（ｂ）に示すように電池ケース１の段部８と金属封口板７に挟まれた部分の絶縁パッキング６は、封口前の厚さａが封口後の厚さｂまで上下方向にだけ圧縮されるのに対し、実施例の場合は、図３（ａ）に示すように比較例と同様の圧縮のほかに、絶縁パッキング６の外周縁のコーナー部１３が電池ケース１の曲率半径の半径方向に更に△ｃだけ圧縮されるため、特に密封性を確保するための要部である絶縁パッキング６の外周縁のコーナー部１３の圧縮率が大きくなり電池の密封性を向上することができる。
【００２３】
なお、本実施例では絶縁パッキング６の外周縁のコーナー部の位置が、電池ケース１の曲率半径で形成される曲線部分の中央部に配置することにより最大の効果が得られたが、曲線上であればコーナー部の圧縮効果が作用することにより電池の密封性を向上することができる。
【００２４】
【発明の効果】
以上のように本発明によれば、電池ケースの開口部を縮径せずに、密閉性が高く、耐漏液性が改善された円筒形電池の製造方法を提供することができる。
【図面の簡単な説明】
【図１】本発明の製造方法により作成した単１形アルカリ乾電池の一実施例の半裁断面図
【図２】（ａ）電池ケースの断面図
（ｂ）開口部近傍に環状の段部を形成した電池ケースの断面図
（ｃ）絶縁パッキングを電池ケースの段部に載置した状態の断面図
【図３】（ａ）本発明の作用効果を説明するための説明図
（ｂ）比較例の作用効果を説明するための説明図
【符号の説明】
１電池ケース
２正極合剤
３セパレータ
４亜鉛負極
５負極集電子
６絶縁パッキング
７金属封口板
８段部
９開口端部
１０立ち上がり部
１１封止剤
１２外周縁鍔部
１３コーナー部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a cylindrical battery.
[0002]
[Prior art]
A conventional cylindrical battery has a metal sealing plate that also serves as a negative electrode terminal through an insulating packing by forming an annular step by projecting inward near an opening of a bottomed cylindrical battery case filled with a power generation element. While supporting and bending the open end of the battery case inward, the insulating packing is vertically moved between the step portion of the battery case and the metal sealing plate sandwiched between the open end of the bent case. There is known a structure which is compressed and sealed.
[0003]
In addition, the opening of the battery case is widened in advance to form a step portion, the metal sealing plate also serving as the negative electrode terminal is supported via the insulating packing, and the insulating packing is formed by reducing the diameter of the opening of the battery case. A method for manufacturing a cylindrical battery that compresses in the radial direction of the battery and bends the open end of the battery case inward to support and seal the metal sealing plate is disclosed. (For example, Japanese Utility Model Publication No. 61-36070)
[0004]
[Problems to be solved by the invention]
However, in the former configuration method of the prior art, the insulating packing is subjected to vertical compression between the step portion of the battery case and the metal sealing plate held between the open end of the bent case, Since the sealing effect is obtained by the repulsive elastic force, the thickness of the insulating packing cannot be reduced too much. As a result, there is a problem that the height occupied by the sealing portion increases, and the volume ratio of the power generating element decreases. Also, if the degree of inward bending of the opening end of the battery case is increased in order to increase the compression in the vertical direction, the opening end surface of the battery case will be deformed in a wavy shape, and the sealing property will be impaired as well as the appearance. there were.
[0005]
On the other hand, in the latter configuration method, when the diameter of the opening of the battery case that has been widened in advance is reduced, a large number of wrinkles are likely to be generated in the vertical direction on the inner wall of the reduced diameter of the battery case, and the minute wrinkles along the wrinkles are likely to occur. There is a problem that the electrolyte leaks due to the creeping phenomenon through a small gap.
[0006]
An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a method of manufacturing a cylindrical battery having high sealing performance and improved liquid leakage resistance.
[0007]
[Means for Solving the Problems]
In order to achieve this object, a method for manufacturing a cylindrical battery according to the present invention includes the steps of: holding an outer peripheral flange of an insulating packing placed on a step portion of a battery case with a metal sealing plate and the battery case; The corner of the outer peripheral edge of the insulating packing on the side contacting the step is arranged on a curve formed with a radius of curvature connected to the step of the battery case and the rising portion above the step, and the opening end of the battery case is inward. It is intended to be folded and sealed.
[0008]
According to this manufacturing method, when the opening end of the battery case is bent inward and sealed, the insulating packing of the portion sandwiched between the step portion of the battery case and the metal sealing plate receives compression in the vertical direction, and the step portion When the bottom surface of the insulating packing moves to the lowest point on the curve formed by the radius of curvature connected to the rising portion above the corner, the corner of the outer peripheral edge of the insulating packing is further compressed in the radial direction of the radius of curvature.
[0009]
That is, without reducing the diameter of the opening of the battery case, the opening and closing curl mold for bending the opening end of the battery case inward is vertically sandwiched between the step portion of the battery case and the metal sealing plate. The part of the insulating packing can be compressed simultaneously in the vertical direction and the radial direction.
[0010]
In addition, under the same vertical moving condition of the sealing curl mold, the outer peripheral edge of the insulating packing, which is a main part for securing the sealing performance, is more important than the conventional sealing method by compressing the insulating packing only in the vertical direction. The compression ratio at the corner is increased, and the sealing performance of the battery is improved.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0012]
FIG. 1 is a half cross-sectional view showing one embodiment of a single alkaline battery manufactured by the manufacturing method of the present invention.
[0013]
In FIG. 1, reference numeral 1 denotes a battery case that also serves as a positive electrode terminal. A cylindrical positive electrode mixture 2 mainly composed of manganese dioxide and graphite is press-fitted into the battery case 1. Reference numeral 3 denotes a bottomed cylindrical separator, in which a zinc negative electrode 4 obtained by dispersing and mixing a zinc alloy powder in a gel electrolyte is filled. Reference numeral 5 denotes a negative electrode current collector, and 6 denotes an insulating packing for closing an opening of the battery case 1. A metal sealing plate 7 serving also as a negative electrode terminal is disposed on the insulating packing 6 by welding to a head of the negative electrode current collector 5. The insulating packing 6 is placed on an annular step 8 formed by projecting the vicinity of the opening of the battery case 1 inward. The battery case 1 is sealed by caulking the open end 9 of the battery case 1 inward.
[0014]
Next, the sealing method which is the production method of the present invention will be specifically described.
The battery case 1 shown in FIG. 2A is made using a nickel-plated steel plate. After press-fitting the positive electrode mixture 2 into the battery case 1, an annular step 8 protruding inward is formed near the opening of the battery case 1 as shown in FIG. did. The inner surface of the battery case 1 connected to the step portion 8 and the rising portion 10 above the step portion 8 had a curved shape formed with a radius of curvature.
[0015]
Next, a sealant 11 was applied to the inner surface side of the step portion 8 and the rising portion 10 above the step portion 8 of the battery case, and power generating elements such as the separator 3 and the zinc negative electrode 4 were arranged as shown in FIG.
[0016]
Further, as shown in FIG. 2C, the insulating packing 6 was placed on the step 8 of the battery case 1 in a state where the metal sealing plate 7 was fitted to the outer peripheral flange 12 of the insulating packing 6. At this time, the dimensions of the insulating packing 6 are set so that the corner 13 of the outer peripheral edge of the insulating packing 6 on the side contacting the step 8 is located at the center of the curved portion formed by the radius of curvature of the battery case 1. did.
[0017]
Next, the opening end 9 of the battery case 1 was bent inward by the up-and-down movement of the sealing curl mold, and the battery case 1 was sealed to form a single alkaline battery (Example) shown in FIG.
[0018]
On the other hand, the corner 13 of the outer peripheral edge of the insulating packing 6 on the side in contact with the step 8 is arranged at the inflection point of the step 8 which is horizontally connected to the curve formed by the radius of curvature of the battery case 1. The dimensions of the insulating packing 6 were set. In addition, the thickness of the outer peripheral edge flange portion 12 of the insulating packing 6 and the degree of fitting of the metal sealing plate 7 were the same as those of the example, and the other method was the same as that of the example to prepare a single alkaline battery (comparative example). .
[0019]
Next, the occurrence rates of liquid leakage in the heat shock test in which the batteries of the above-mentioned Examples and Comparative Examples were subjected to a heat shock test at 80 ° C. for 12 hours and at −20 ° C. for 12 hours were compared with those in Table 1. Is shown. The number of tests was 100, and the number of cycles was 10 cycles.
[0020]
[Table 1]

[0021]
As is clear from Table 1 (FIG. 1), the liquid leakage occurred in the comparative example, but the liquid leakage did not occur in the example, indicating that the liquid leakage resistance was improved.
[0022]
Under the same moving condition of the sealing curl mold in the vertical direction, that is, when the sealing height dimension is the same, in the case of the comparative example, as shown in FIG. The thickness of the insulating packing 6 sandwiched between the sealing plates 7 is compressed only in the vertical direction from the thickness a before sealing to the thickness b after sealing, whereas in the case of the embodiment, FIG. As shown in FIG. 5, in addition to the same compression as in the comparative example, since the corner 13 of the outer peripheral edge of the insulating packing 6 is further compressed by Δc in the radial direction of the radius of curvature of the battery case 1, particularly the sealing performance is secured. The compression ratio of the corner portion 13 of the outer peripheral edge of the insulating packing 6, which is a main part of the battery, is increased, and the sealing performance of the battery can be improved.
[0023]
In this embodiment, the maximum effect is obtained by arranging the corner of the outer peripheral edge of the insulating packing 6 at the center of the curved portion formed by the radius of curvature of the battery case 1. In this case, the sealing effect of the battery can be improved by the effect of the compression of the corner portion.
[0024]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a method for manufacturing a cylindrical battery having high sealing performance and improved liquid leakage resistance without reducing the diameter of the opening of the battery case.
[Brief description of the drawings]
FIG. 1 is a half sectional view of an embodiment of a single type alkaline dry battery produced by the manufacturing method of the present invention. FIG. 2 (a) is a sectional view of a battery case, and FIG. 2 (b) is an annular step formed near an opening. FIG. 3 (a) is a cross-sectional view of a state where the insulating packing is placed on a step portion of the battery case. FIG. 3 (a) is an explanatory view for explaining the operation and effect of the present invention, and FIG. Explanatory diagram for explaining the operation and effect [Description of reference numerals]
REFERENCE SIGNS LIST 1 Battery case 2 Positive electrode mixture 3 Separator 4 Zinc negative electrode 5 Negative current collector 6 Insulating packing 7 Metal sealing plate 8 Step 9 Open end 10 Rising section 11 Sealant 12 Outer edge flange 13 Corner

Claims

An annular step is formed by projecting inward the vicinity of the opening of the cylindrical battery case filled with the power generating element, and the outer peripheral flange of the insulating packing placed on the step of the battery case is sealed with a metal sealing plate. And a method of manufacturing a cylindrical battery in which the battery case is sandwiched and the open end of the battery case is bent inward and sealed, and a corner portion of an outer peripheral edge of the insulating packing in contact with the step portion is provided. Are arranged on a curve formed with a radius of curvature connected to a step portion of the battery case and a rising portion above the battery case, and an open end of the battery case is bent inward to seal the battery. Production method.