JP2008282601A - Alkaline dry cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce occurrence of mounting defect of an insulating ring to a negative electrode terminal board and an appearance defect caused by it, and to suppress the spray-shaped jet of an alkali electrolyte, even if the gas pressure in an alkaline dry cell increases, in a manufacturing process of the alkaline dry cell. <P>SOLUTION: In this alkaline dry cell 1 including a battery casing 2 which has an opening part and in which a power generating element containing the alkali electrolyte is housed, an assembled sealing body 3 equipped with a resin sealing body 10 having a thin thickness part 10a ruptured by a gas pressure in the inside of the battery casing and a negative electrode terminal board 11 to seal the battery case 2 by being mounted to the opening part of the battery casing 2, an insulating ring 4 mounted to the negative electrode terminal board 11, and an exterior label 5 provided to make contact with the peripheral surface of the battery case 2, a positioning part 12 coming into contact with the negative electrode terminal board 11, and an air gap forming part 13 to form an air gap 14 together with the negative electrode terminal board 11 are provided on the inner peripheral surface of the insulating ring 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an alkaline battery.

  Alkaline batteries have high capacity, excellent discharge characteristics, and are compatible with manganese batteries in terms of operating voltage and battery size, and are widely used as power sources for electrical and electronic equipment that require relatively large power. It's being used. Examples of such electric and electronic devices include digital cameras, digital video cameras, portable DVD players, portable MD players, portable CD players, headphone stereos, and toys with motors. Alkaline batteries are excellent in safety and reliability when used, but in the current situation where higher capacity is achieved, further improvements in safety and reliability are required.

  The alkaline dry battery has a structure shown in FIGS. 5 and 6, for example. FIG. 5 is a front view showing the structure of a conventional AA alkaline battery 30. The alkaline battery 30 has a cylindrical shape, and its internal structure is symmetrical with respect to the axis when viewed from the front. Therefore, in FIG. 5, from the axis to one end in the direction perpendicular to the axis is shown as a longitudinal sectional view. FIG. 6 is an enlarged longitudinal sectional view showing a configuration of a main part of the alkaline dry battery 30 shown in FIG. The alkaline battery 30 includes a battery case 31, a positive electrode mixture 32, a gelled negative electrode 33, a separator 34, a negative electrode current collector 35, a negative electrode terminal plate 36, a resin sealing body 37, an insulating ring 38, and an exterior label 39.

  The battery case 31 is a bottomed cylindrical container-like member having an opening at one end in the longitudinal direction. The positive electrode mixture 32 is formed in a hollow cylindrical shape, and is provided so that the outer peripheral surface thereof is in contact with the inner peripheral surface of the battery case 31. The gelled negative electrode 33 is a gelled electrolyte in which zinc powder is dispersed. The separator 34 is provided between the positive electrode mixture 32 and the gelled negative electrode 33 to electrically insulate them. The positive electrode mixture 32, the gelled negative electrode 33, and the separator 34 are impregnated with an alkaline electrolyte. The negative electrode current collector 35 is a metal nail-like member, and is provided such that the top is electrically connected to the negative electrode terminal plate 36 and the end opposite to the top is present in the gelled negative electrode 33. The negative electrode terminal plate 36 is a hat-like circular member including a convex portion 36a, a rising portion 36b, and a gas venting discharge hole 36c (hereinafter referred to as “gas discharge hole 36c”). The convex portion 36 a is provided in the central portion of the negative electrode terminal plate 36. The rising portion 36b is a side surface portion of the convex portion 36a. The gas discharge hole 36c is formed in the rising portion 36b so as to penetrate the negative electrode terminal plate 36 in the thickness direction. The negative electrode terminal plate 36 is electrically connected to the negative electrode current collector 35. In addition, the peripheral edge of the opening of the battery case 31 is caulked to the peripheral edge of the negative electrode terminal plate 36 via the resin sealing body 37. The resin sealing body 37 is a member that combines the opening end of the battery case 31 and the negative electrode terminal plate 36 to seal the opening of the battery case 31, and is a thin-walled portion that breaks according to the gas pressure in the battery case 31. 37a. The insulating ring 38 is provided so that the inner peripheral surface thereof is in contact with the rising portion 36 b of the negative electrode terminal plate 36, and is supported by the battery case 31 and the exterior label 39.

  The alkaline battery 30 can be manufactured, for example, by a manufacturing method including a battery element storage step, a sealing step, and a finishing step. In the battery element storage step, the positive electrode mixture 32, the separator 34, and the gelled negative electrode 33 are stored in the battery case 31 in this order, and an alkaline electrolyte is injected into the separator 34. In the sealing step, first, the nail-like top portion of the negative electrode current collector 35 is welded to the inner surface of the negative electrode terminal plate 36, and the negative electrode current collector 35 is inserted into a through hole formed in the central portion of the resin sealant 37. A sealing body is produced. The assembly sealing body is attached to the opening of the battery case 31, and the peripheral edge of the opening of the battery case 31 is bent and crimped to the peripheral edge of the negative electrode terminal plate 36 via the resin sealing body 37. Thereby, the opening part of the battery case 31 is sealed, and a unit cell is obtained. In the finishing process, first, the exterior label 39 is wound around the peripheral surface of the unit cell, that is, the peripheral surface of the battery case 31 in a cylindrical shape. Next, the insulating ring 38 is attached to the negative electrode terminal plate 36 so that the inner peripheral surface thereof is in contact with the rising portion 36 b of the negative electrode terminal plate 36. Further, the exterior label 39 is thermally contracted, and the insulating ring 38 is sandwiched between the battery case 31 and the exterior label 39. As a result, the insulating ring 38 is supported, and the product of the alkaline battery 30 is obtained.

  In the alkaline battery 30, the frequency of occurrence is extremely low, but gas may be generated inside the battery due to a short circuit inside the battery, incorrect charging, etc., and the battery may be damaged. In order to prevent this, the resin sealing body 37 is provided with a thin portion 37a. The thin portion 37a is broken when the pressure inside the battery exceeds a predetermined value due to the generation of gas. The gas inside the battery is discharged outside the battery through the broken thin portion 37a, the gas discharge hole 36c, and the gap between the negative electrode terminal plate 36 and the insulating ring 38 in this order. The conventional insulating ring 38 is known as a member that is relatively susceptible to mounting failure or mounting displacement in the battery manufacturing process. Moreover, the mounting failure or mounting misalignment of the insulating ring 38 causes a defective appearance of the battery and causes a problem that the product yield is lowered.

  In view of such a problem, for example, an alkaline dry battery including an insulating ring provided with a protrusion on an inner peripheral surface in contact with the negative electrode terminal plate has been proposed (for example, see Patent Document 1). According to Patent Document 1, an attempt is made to reduce the occurrence of defective mounting or mounting displacement of the insulating ring in the battery manufacturing process by providing a protrusion on the inner peripheral surface of the insulating ring. However, since the insulating ring is a thin flat plate member and easily deforms, accurate positioning cannot be achieved simply by providing a protrusion on the inner peripheral surface. It cannot be reduced. Moreover, this tendency is conspicuous in AA or AAA alkaline batteries, which have a smaller outer diameter than the AA type, and are lighter than the AA type, which is a chronic issue in speeding up the manufacturing process of alkaline batteries. It has become.

  Moreover, the alkaline dry battery 40 shown in FIG. 7 is proposed (for example, refer patent document 2). FIG. 7 is an enlarged longitudinal sectional view showing the structure of the main part of the alkaline dry battery 40. The alkaline battery 40 has the same structure as the alkaline battery 30 except that it has an insulating ring 38 a instead of the insulating ring 38. Compared to the insulating ring 38, the insulating ring 38 a has a cylindrical portion that extends from the contact portion with the rising portion 36 b of the negative electrode terminal plate 36 to the outer peripheral surface of the gas discharge hole 36 c portion. Further, in the alkaline battery 40, the outer diameter of the convex portion 36a of the negative electrode terminal plate 36 and the inner diameter of the insulating ring 38a have a specific relationship. In Patent Document 2, by adopting the above-described configuration, leakage of the alkaline electrolyte is prevented and the reliability of the alkaline battery 40 is improved. However, even in the technique of Patent Document 2, the thin flat insulating ring 38a has insufficient mechanical strength and cannot be sufficiently adhered to the rising portion 36b of the negative electrode terminal plate 36. For this reason, it is difficult to reliably prevent leakage of the alkaline electrolyte. In addition, when the internal pressure of the battery exceeds a certain pressure, a slight gap is generated at the contact portion between the surface of the rising portion 36b and the cylindrical portion of the insulating ring 38a, and the alkaline electrolyte is sprayed out of the battery at once in a spray form. In addition, a wide range starting from the alkaline battery 40 is contaminated.

JP 2005-19117 A JP 2002-170539 A

  An object of the present invention is an insulating ring for an alkaline battery, and even if the manufacturing process of the alkaline battery is speeded up, mounting failure is hardly caused, the product yield is remarkably improved, and the pressure inside the battery is increased. Even so, it is to provide an alkaline battery including an insulating ring that can remarkably suppress the ejection of the alkaline electrolyte.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have succeeded in obtaining an insulating ring that fulfills the purpose and completed the present invention. The insulating ring is provided with a positioning portion and a gap forming portion on the inner peripheral surface that comes into contact with the negative electrode terminal plate. A positioning part is a part which contacts the surface of a negative electrode terminal board, when attaching an insulating ring to a negative electrode terminal board. By providing multiple positioning parts at intervals, in the alkaline battery manufacturing process, the mounting accuracy of the insulating ring to the negative electrode terminal plate is improved, and the occurrence of defective mounting of the insulating ring and hence the appearance of the battery is significantly reduced. It becomes. Moreover, a space | gap formation part is a part which forms a space | gap part between negative electrode terminal plates, when attaching an insulating ring to a negative electrode terminal plate. When the gap is formed, gas is smoothly discharged to the outside of the battery as the pressure inside the battery increases. Therefore, it is possible to prevent the alkaline electrolyte from being ejected rapidly in a spray form and contaminating a wide area.

The present invention
A battery case having an opening and accommodating a power generation element;
The battery case includes an outer label provided in contact with the outer peripheral surface of the battery case, a resin sealing body having a thin portion that is broken by the gas pressure inside the battery case, and a negative electrode terminal plate formed with a gas discharge hole. An assembled sealing body that is mounted to form a sealing portion;
A ring-shaped member that is mounted on the negative electrode terminal plate so that at least a part of the inner peripheral surface is in contact with the surface of the negative electrode terminal plate, and is sandwiched between the opening end portion of the battery case and the end portion of the exterior label on the battery case opening side And an alkaline battery including an insulating ring provided with a positioning portion that abuts on the negative electrode terminal plate surface on the inner peripheral surface and a void forming portion that forms a void portion for venting gas together with the negative electrode terminal plate surface. .

  It is preferable that a plurality of positioning portions and gap forming portions are alternately provided on the inner peripheral surface of the insulating ring.

  The shape of the gap in the direction perpendicular to the axis of the insulating ring is preferably V-shaped, U-shaped or I-shaped.

  The shape of the region surrounded by the inner peripheral surface of the insulating ring in the direction perpendicular to the axis of the insulating ring is preferably a polygon.

  As for the shape of the region surrounded by the inner peripheral surface of the insulating ring in the direction perpendicular to the axis of the insulating ring, n is preferably an integer of 6 or more.

  The shape of the region surrounded by the inner peripheral surface of the insulating ring in the direction perpendicular to the axis of the insulating ring is a regular m-gon with m being an integer of 4 or more, and corresponds to the apex angle of the regular m-gon. It is preferable that the part has a circular arc shape.

  It is preferable that a plurality of notches are provided on the inner peripheral surface of another form of the insulating ring.

  Even if the alkaline dry battery of the present invention is manufactured at high speed, the defective product rate due to defective mounting of the insulating ring to the negative electrode terminal plate is very low, in other words, the product yield is very high. It can be advantageously manufactured. Also, in the alkaline battery of the present invention, even if a short circuit occurs or it is accidentally charged, the alkaline electrolyte does not erupt suddenly and pollute a wide area, so it is excellent in safety and reliability. ing.

The alkaline dry battery of the present invention is characterized by using an insulating ring provided with a positioning portion and a gap forming portion on the inner peripheral surface in contact with the negative electrode terminal plate. Except for the insulating ring, the same configuration as that of a conventional alkaline battery can be adopted. Therefore, as constituent members other than the insulating ring, those conventionally used in the field of alkaline dry batteries can be used.
FIG. 1 is a drawing schematically showing a configuration of an alkaline dry battery 1 according to a first embodiment of the present invention. FIG. 1A is a longitudinal sectional view showing a configuration of a main part of the alkaline dry battery 1. FIG. 1B is a plan view showing a state in which the insulating ring 4 is mounted on the negative terminal plate 11. The alkaline battery 1 has a cylindrical shape and has the same structure as the alkaline battery 30 shown in FIGS. 5 and 6 except that the insulating ring 4 is included instead of the insulating ring 38. The alkaline battery 1 includes a battery case 2, an assembly sealing body 3, an insulating ring 4, an exterior label 5, and a negative electrode current collector 6.

  The battery case 2 is a bottomed cylindrical container member, and in the longitudinal direction, one end (not shown) is provided with a positive terminal (not shown) protruding outward from the surface of the end and the other end. The part 2a becomes an opening. Hereinafter, the other end 2a is referred to as an “opening end 2a”. The opening-side end 2a is bent inward of the battery case 2, and the opening-side end 2a is formed with a recess 2b that is recessed with respect to the surface of the battery case 2. A groove extending in the circumferential direction is formed on the inner peripheral surface of the battery case 2 by the opening-side end 2a and the recess 2b. The battery case 2 is produced using, for example, a steel plate, a steel plate with nickel plating on one side or both sides. For example, a conductive coating agent may be applied to the inner surface of the battery case 2. Examples of the conductive coating agent include graphite (natural graphite, artificial graphite, carbon black, acetylene black, etc.), resin (acrylic resin, etc.), water, and the like.

In the battery case 2, a power generation element (not shown) and an alkaline electrolyte are accommodated from the opening. Here, the power generation elements are a positive electrode mixture, a separator, and a gelled negative electrode (not shown).
The positive electrode mixture is formed in a hollow cylindrical shape, and is provided so that the outer peripheral surface thereof is in contact with the inner peripheral surface of the battery case 2. The positive electrode mixture is produced, for example, by compression-molding granules containing a positive electrode active material into a hollow cylindrical shape. The granules containing the positive electrode active material can be obtained, for example, by stirring and mixing the positive electrode active material, the conductive material, and the alkaline electrolyte, compression-molding the resulting mixture to obtain flakes, and pulverizing the flakes. It is preferable to classify the granules with, for example, a sieve and use 10 to 100 mesh. Examples of the positive electrode active material include manganese dioxide, nickel oxyhydroxide, and a mixture of two or more thereof. As the conductive material, for example, graphite can be used. Examples of the alkaline electrolyte include an aqueous potassium hydroxide solution. The potassium hydroxide concentration of the aqueous potassium hydroxide solution is preferably about 30 to 45% by weight.

A separator is arrange | positioned between a positive mix and a gel-like negative electrode, and while being used in order to insulate these, alkaline electrolyte solution is inject | poured. A separator is produced in the shape which has internal spaces, such as a bottomed cylindrical shape and a bag shape, for example. The separator is made of, for example, an insulating porous sheet such as a nonwoven fabric. The porous sheet preferably contains a hydrophilic material. Specific examples of the porous sheet include, for example, a nonwoven fabric mainly composed of polyvinyl alcohol fiber and cellulose fiber, a nonwoven fabric blended with polyvinyl alcohol as a polyvinyl alcohol fiber, cellulose fiber and pulp fiber binder, and a microporous material. The laminated body etc. which laminate | stack the above nonwoven fabric on both surfaces of the thickness direction of a film are mentioned. Here, examples of the polyvinyl alcohol fiber include polyvinyl alcohol fiber and vinylon fiber. Examples of the cellulosic fiber include cellulose fiber, acetylcellulose fiber, mercerized pulp fiber, rayon fiber, and polynosic rayon fiber. Moreover, in the case of a bottomed cylindrical separator, the cylindrical portion and the bottom portion may be made of different materials.
As the alkaline electrolyte to be injected into the separator, the same electrolyte used for preparing the positive electrode mixture can be used. The alkaline electrolyte used here may contain lithium hydroxide, an aluminum compound, or the like. Examples of the aluminum compound include aluminum hydroxide.

  The gelled negative electrode includes, for example, a negative electrode active material, an alkaline electrolyte, and a gelling agent, and fills the internal space of the separator. Examples of the negative electrode active material include zinc powder and zinc alloy powder containing aluminum. As the alkaline electrolyte, the same one as that used when preparing the positive electrode mixture can be used. Examples of the gelling agent include polyacrylic acid, sodium polyacrylate, and a mixture thereof. The gelled negative electrode can be prepared, for example, by mixing a negative electrode active material, an alkaline electrolyte, and a gelling agent.

  The negative electrode current collector 6 is a rod-like member that penetrates into the gelled negative electrode. The negative electrode current collector 6 may be formed as a nail-like member. In that case, a portion corresponding to the top portion of the nail-shaped member contacts the negative electrode terminal plate 11, and a rod-shaped portion extending in one direction from the top portion penetrates into the gelled negative electrode. The negative electrode current collector 6 can be produced, for example, by pressing a metal material. As the metal material, for example, a wire such as silver, copper, or brass can be used. The surface of the negative electrode current collector 6 may be plated with tin, indium, or the like, for example, in order to eliminate or conceal impurities adhering during press working.

The assembly sealing body 3 includes a resin sealing body 10 and a negative electrode terminal plate 11, and is attached to the opening of the battery case 2 to form a sealing portion that seals the battery case 2.
The resin sealing body 10 is a circular member made of a synthetic resin, and includes a center portion (not shown), a thin portion 10a, and an outer peripheral portion 10b. A through hole (not shown) that penetrates the center portion in the thickness direction is formed in the center portion. The through hole preferably has the same axis as the resin sealing body 10. The negative electrode current collector 6 is press-fitted into the through hole.
The thin wall portion 10a extends in an annular shape between the center portion of the surface facing the battery element of the resin sealing body 10 and the outer peripheral portion 10b when the assembly sealing body 3 is attached to the opening of the battery case 2. It is provided as a concave recess. The thin-walled portion 10a is a portion having a thickness smaller than that of the central portion and the outer peripheral portion 10b. The thin-walled portion 10a breaks when the gas pressure inside the battery case 2 rises more than necessary, and becomes a passage for discharging the gas inside the battery case 2 to the outside. . That is, the thin portion 10a functions as a safety valve.

The outer peripheral portion 10b is formed so as to extend radially about the axis of the resin sealing body 10, and when the assembly sealing body 3 is attached to the opening portion of the battery case 2, the peripheral portion is an opening of the battery case 2. It is provided so as to be in pressure contact with the groove portion inner peripheral surface of the side end portion 2a.
The resin sealing body 10 can be produced, for example, by injection molding a synthetic resin such as polyamide or polyolefin into a predetermined size and shape. Among the synthetic resins, polyamide is preferable in view of excellent alkali resistance and relatively low elongation at high temperature, and 6,6-nylon, 6,10-nylon, 6,12-nylon and the like are particularly preferable. preferable.

The negative electrode terminal plate 11 is a circular member having a convex portion at the center, that is, a member having a substantially hat shape, and includes a flange portion 11a, a convex portion 11b, and a rising portion 11c.
The collar portion 11 a is a portion corresponding to the collar of the hat, and is a peripheral edge portion of the negative electrode terminal plate 11. The flange portion 11 a is fitted into the groove portion of the opening side end portion 2 a of the battery case 2 via the peripheral edge portion of the outer peripheral portion 10 b of the resin sealing body 10. As a result, the peripheral edge portion of the outer peripheral portion 10 b is pressed against the inner surface of the groove portion of the battery case 2.
The convex portion 11b is provided so as to protrude outward from the surface of the flange portion 11a. The convex portion 11 b is preferably formed in a columnar shape that shares the axis with the negative electrode terminal plate 11.

The rising part 11c is a side part of the convex part 11b. A gas discharge hole 11x (hereinafter simply referred to as “discharge hole 11x”) is formed in the rising portion 11c. The discharge hole 11x is a through hole that penetrates the negative electrode terminal plate 11 in the thickness direction. The discharge hole 11x becomes a passage for discharging the gas inside the battery case 2 discharged when the thin portion 10a of the resin sealing body 10 is broken to the outside of the alkaline battery 1. The discharge hole 11x is preferably formed so that the center of the opening portion on the surface of the negative electrode terminal plate 11 is located at the rising portion 11c in consideration of the gas exhaust efficiency, the design freedom of the resin sealing body 10, and the like. Therefore, if the center of the opening portion is at the rising portion 11c, at least a part of the opening portion may be located on the surface of the boundary between the flange portion 11a and the rising portion 11c, and further beyond the boundary portion, the flange portion 11a. It may be located on the surface. A plurality of discharge holes 11x are preferably formed, and a plurality of discharge holes 11x are more preferably formed at equal intervals in the circumferential direction of the rising portion 11c. The opening area of the discharge hole 11x is preferably about 0.5 mm ^{2 in} consideration of gas exhaust efficiency, suppression of scattering of the alkaline electrolyte, and the like. If the opening area is less than 0.5 mm ² , the gas exhaust efficiency may be insufficient. The negative electrode terminal plate 11 can be produced, for example, by press-molding a metal plate into a predetermined size and shape. As the metal plate, for example, a nickel-plated steel plate or a tin-plated steel plate can be used.

The assembly sealing body 3 connects, for example, the inner surface of the convex portion 11b of the negative electrode terminal plate 11 and the top of the negative electrode current collector 6, and then at least a part other than the top of the negative electrode current collector 6 is centered on the resin sealing body 10. The resin sealing body 10 and the negative electrode terminal plate 11 can be assembled by being press-fitted into the through-holes of the parts, and assembled.
A reinforcing washer (not shown) may be used together with the negative terminal plate 11. Thereby, for example, the mechanical strength of the assembly sealing body 3 is further increased.

  The insulating ring 4 is a circular ring-shaped member, for example, assists the sealing of the opening of the battery case 2 by the assembly sealing body 3, and particularly has a function of covering and protecting the opening-side end 2a of the battery case 2. Have. The insulating ring 4 has a function of smoothly discharging the gas inside the alkaline battery 1 to the outside while suppressing the ejection of the alkaline electrolyte when the gas pressure rises more than necessary inside the alkaline battery 1. Also have. The insulating ring 4 is attached to the negative electrode terminal plate 11, and the peripheral edge or peripheral edge thereof and the vicinity thereof are sandwiched between the opening end 2a of the battery case 2 and the battery case 2 opening side end 2a of the exterior label 5 described later. Is supported by When the insulating ring 4 is attached to the negative electrode terminal plate 11, at least a part of the inner peripheral surface of the insulating ring 4 contacts the surface of the negative electrode terminal plate 11, preferably the surface of the rising portion 11c.

  A region surrounded by the inner peripheral surface of the insulating ring 4 is a hollow portion into which the convex portion 11 b of the negative electrode terminal plate 11 is inserted when the insulating ring 4 is attached to the negative electrode terminal plate 11. The insulating ring 4 preferably has a polygonal shape (hereinafter referred to as “inner peripheral surface shape”) in a region surrounded by the inner peripheral surface in a direction perpendicular to the axis of the insulating ring 4. At this time, as will be described later, since at least a part of the polygonal side becomes the positioning portion 12, a plurality of positioning portions 12 can be provided by making the cross-sectional shape polygonal. Moreover, since the shape of a polygon is a comparatively simple shape, productivity at the time of manufacturing the insulating ring 4 by press punching etc. can be improved, for example.

  The inner peripheral surface shape of the insulating ring 4 is more preferably a regular n-gon having n of 6 or more, and particularly preferably a regular n-gon having n being an even number of 6 or more. In this embodiment, it is a regular octagon. By adopting such a simple shape, the design of the die when the insulating ring 4 is subjected to press punching and the press punching itself are further facilitated, which can be manufactured industrially advantageously. Supply becomes possible. Furthermore, since the weight balance is good, positioning in the manufacturing process of the alkaline dry battery 1 becomes easier. Moreover, it is preferable also from the point from which the alkaline dry battery 1 with a further favorable external appearance is obtained. If n is less than 6, the insulating ring 4 may not be able to reliably cover the end face of the opening side end 2a of the battery case 2. When the inner peripheral surface shape of the insulating ring 4 is a regular n-square shape, it is preferable that the insulating ring 4 is mounted on the negative electrode terminal plate 11 having the same diameter as the regular inscribed circle.

A positioning portion 12 and a gap forming portion 13 are provided on the inner peripheral surface of the insulating ring 4. In the present embodiment, a plurality of positioning portions 12 and a plurality of gap forming portions 13 are provided alternately. Thereby, it is possible to achieve both reliable attachment of the insulating ring 4 to the negative electrode terminal plate 11 and smooth discharge of gas from the inside of the alkaline battery 1.
The positioning part 12 is a part in contact with the surface of the rising part 11c when the insulating ring 4 is attached to the negative terminal plate 11. A plurality of positioning portions 12 are preferably provided. When the inner peripheral surface shape of the insulating ring 4 is a polygon, the center portion of the side of the polygon is the positioning portion 12. In the present embodiment, the substantially central part of each side of the regular octagon is the positioning part 12, and the eight positioning parts 12 are provided at equal intervals. By providing a plurality of positioning portions 12, the insulating ring 4 is more reliably attached to a predetermined position of the negative electrode terminal plate 11 in the manufacturing process of the alkaline dry battery 1. As a result, the mounting accuracy of the insulating ring 4 to the negative electrode terminal plate 11 is increased, the mounting failure of the insulating ring 4 and the appearance failure of the alkaline dry battery 1 are significantly reduced, and the product yield is remarkably improved.

  When the insulating ring 4 is attached to the negative electrode terminal plate 11, the gap forming portion 13 does not contact the surface of the negative electrode terminal plate 11, and the gap portion 14 is formed together with a portion 11 y facing the gap forming portion 13 on the surface of the negative electrode terminal plate 11. This is the part to be formed. It can also be said that the gap portion 14 is a through-hole penetrating the attachment body of the insulating ring 4 to the negative electrode terminal plate 11 in the thickness direction. In the present embodiment, a plurality of gaps 14 are provided, but the present invention is not limited to this, and even if there is only one gap, the function can be sufficiently achieved. By providing the gap portion 14, even when a sudden gas pressure rise occurs inside the alkaline dry battery 1, the gas flowing out through the fractured portion of the thin-walled portion 10 a and the discharge hole 11 x smoothly flows to the outside of the alkaline dry battery 1. Discharged. The shape of the gap 14 in the direction perpendicular to the axis of the insulating ring 4 (hereinafter referred to as “shape of the gap 14”) is not particularly limited, but is V-shaped (or triangular), U-shaped (or A crescent shape) or an I-shape is preferred. In the present embodiment, the space 14 has a V-order shape or a triangular shape.

  The insulating ring 4 can be produced, for example, by press punching a plate-like material made of an insulating material into a predetermined size and shape. Examples of the insulating material include synthetic resin and rubber. Examples of the synthetic resin include thermoplastic resins such as polypropylene, polystyrene, polyethylene, polyethylene terephthalate, and polybutylene terephthalate, and thermosetting resins such as styrene resin and urethane resin. Examples of the rubber include natural rubber, styrene butadiene rubber, butadiene rubber, ethylene propylene rubber, nitrile rubber, and silicon rubber. In addition, as a plate-like material made of an insulating material, paper or a nonwoven fabric containing a synthetic resin such as vinylon or rayon can be used.

The exterior label 5 is provided so as to be in contact with at least the outer circumferential surface of the battery case 2 in the longitudinal direction. For the exterior label 5, for example, a plate-like object such as a heat-shrinkable resin film or sheet is used. As the heat-shrinkable resin, at least one selected from the group consisting of polyethylene, polyvinyl chloride, polystyrene, and polyethylene terephthalate can be used. For mounting the exterior label 5 on the battery case 2, for example, a plate of heat-shrinkable resin is formed into a cylindrical shape, and a unit cell is inserted into the cylindrical material and heated to shrink the heat-shrinkable resin. Is done by. In addition, a plate of heat-shrinkable resin may be directly attached to the outer peripheral surface in the longitudinal direction of the unit cell and heated. The heat-shrinkable resin is heated, for example, by blowing hot air. As a result, the heat-shrinkable resin adheres to the outer circumferential surface of the battery case 2 in the longitudinal direction. At the same time, at the end of the battery case 2 where the assembly sealing body 3 is mounted, the end of the outer label 5 is in close contact with the insulating ring 4, and the insulating ring 4 is connected to the opening side end 2 a of the battery case 2 and the outer label 5. Of the battery case 2 at the opening side.
The alkaline dry battery 1 includes, for example, a power generation element housed in a battery case 2, an alkaline electrolyte is injected, the opening of the battery case 2 is sealed with an assembly sealing body 3, and a unit cell is manufactured. The battery can be manufactured by sequentially attaching the insulating ring 4 and the exterior label 5 to the battery.

FIG. 2 is a plan view schematically showing the configuration of another form of the insulating rings 16, 17, 18.
The insulating ring 16 shown in FIG. 2 (a) has a structure similar to that of the insulating ring 4, the inner peripheral surface shape is a regular hexagon, and the inner peripheral surface has six positioning portions 16a and six The gap forming portions 16b are alternately provided. The positioning part 16a is a substantially central part of each side of the regular hexagon. Therefore, the six positioning parts 16a are provided at equal intervals. The positioning portion 16 a contacts the surface of the negative electrode terminal plate 11 when the insulating ring 16 is attached to the negative electrode terminal plate 11, and securely attaches the insulating ring 16 to the negative electrode terminal plate 11. The gap forming portion 16b includes a vertex angle in a regular hexagon and a portion from the vertex angle to the positioning portions 16a of two sides forming the vertex angle. Accordingly, six gap forming portions 16b are also provided at equal intervals. The gap forming portion 16 b forms a gap portion 16 c together with a part of the surface of the negative electrode terminal plate 11 when the insulating ring 16 is attached to the negative electrode terminal plate 11. The gap portion 16c is a space surrounded by the gap forming portion 16b and the surface of the negative electrode terminal plate 11 facing the gap forming portion 16, and is a through-hole that penetrates the attachment body of the insulating ring 16 to the negative electrode terminal plate 11 in the thickness direction. It can also be said. The shape of the gap 16c is substantially V-shaped or substantially triangular. The gap portion 16 c has the same function as the gap portion 14.
The insulating ring 16 can be suitably attached to the negative electrode terminal plate 11 having the same diameter as the regular hexagonal inscribed circle that is the shape of the inner peripheral surface thereof. Moreover, since the inner peripheral surface shape of the insulating ring 16 is simpler than that of the insulating ring 4, productivity when the insulating ring 16 is manufactured can be further increased.

  The insulating ring 17 shown in FIG. 2 (b) has a structure similar to that of the insulating ring 4, and its inner peripheral surface shape is a regular m-gonal shape in which the apex portion is formed in an arc shape (where m is an integer of 4 or more). It is characterized by On the inner peripheral surface of the insulating ring 17, m positioning portions 17 a and m gap forming portions 17 b are alternately provided. In the present embodiment, m = 4. As a result, even if the inner peripheral surface shape slightly changes with the wear of the mold used when the insulating ring 17 is manufactured by press punching, the insulating ring 17 that can sufficiently perform the desired function is obtained. . That is, the allowable range with respect to the change of the inner peripheral surface shape is expanded, and the burden during manufacturing can be reduced. Further, since the length from the apex portion to the peripheral edge of the insulating ring 17 can be sufficiently secured, the mechanical strength of the insulating ring 17 itself can be improved. Further, when the apex angle is formed in an arc shape, the end surface of the battery case 2 in the sealing portion can be reliably covered even if m is 4. When m is less than 4, there is a possibility that the end face of the opening side end 2a of the battery case 2 of the insulating ring 4 cannot be reliably covered. The insulating ring 17 has the same function as the insulating ring 4.

  The positioning portion 17a is substantially at the center of each side of a regular m-square shape in which the vertex portion is formed in an arc shape. Therefore, m positioning portions 17a are provided at equal intervals. In this embodiment, m = 4. The positioning portion 17 a contacts the surface of the negative electrode terminal plate 11 when the insulating ring 17 is attached to the negative electrode terminal plate 11, and securely attaches the insulating ring 17 to the negative electrode terminal plate 11. The air gap forming portion 17b includes an apex angle portion formed in an arc shape and a portion from the apex angle portion to the positioning portions 17a of the two sides forming the apex angle portion. The m gap forming portions 17b are also provided at equal intervals. The gap forming portion 17 b forms a gap portion 17 c together with a part of the surface of the negative electrode terminal plate 11 when the insulating ring 17 is attached to the negative electrode terminal plate 11. The gap portion 17c is a space surrounded by the gap forming portion 17b and the surface of the negative electrode terminal plate 11 facing the gap forming portion 17b, and is a through hole that penetrates the attachment body of the insulating ring 17 to the negative electrode terminal plate 11 in the thickness direction. It can also be said. The shape of the gap 17c is approximately U-shaped or approximately crescent. The gap portion 17 c has the same function as the gap portion 14. The insulating ring 17 can be suitably attached to the negative electrode terminal plate 11 having the same diameter as a regular m-square inscribed circle whose apex angle portion is formed in an arc shape.

  The insulating ring 18 shown in FIG. 2C has a plurality of positioning portions 18a and a plurality of gap forming portions 18b provided alternately on the inner peripheral surface thereof in a cross section perpendicular to the axis. The positioning portion 18 a has an apex angle that protrudes toward the axis of the insulating ring 18, and the apex of the apex angle contacts the surface of the negative electrode terminal plate 11 when the insulating ring 18 is attached to the negative electrode terminal plate 11. As a result, the insulating ring 18 is mounted on the negative terminal plate 11 almost accurately to the extent that there is no practical problem. The gap forming portion 18b is provided as a notch portion with respect to a virtual plane connecting the vertices of the two positioning portions 18a between two adjacent positioning portions 18a. The gap forming portion 18b has an apex angle that protrudes in a direction opposite to the direction toward the axial center of the insulating ring 18, and when the insulating ring 18 is attached to the negative electrode terminal plate 11, together with a part of the surface of the negative electrode terminal plate 11 The gap 18c is formed. In addition, the positioning part 18a and the space | gap formation part 18b which adjoin each share one of the two sides which form each vertex angle. The gap portion 18c is a space surrounded by the gap forming portion 18b and the surface of the negative electrode terminal plate 11 facing the gap forming portion 18b, and is a through hole that penetrates the mounting body of the insulating ring 18 to the negative electrode terminal plate 11 in the thickness direction. It can also be said. The shape of the gap 18c is substantially triangular. The insulating ring 18 can be suitably attached to the negative electrode terminal plate 11 having the same diameter as a circle inscribed at the apexes of the plurality of positioning portions 18a. Even if the insulating ring 18 is used, the same effect as the insulating ring 4 can be obtained.

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the examples shown below.
Example 1
(1) Preparation of assembly sealing body 3 The resin sealing body 10 was manufactured as a molded body having a predetermined size and shape by injection molding using 6,12-nylon. The annular thin portion 10a has a thickness of 0.25 mm.
The negative electrode terminal plate 11 was a nickel-plated steel plate having a thickness of 0.4 mm, and had an outer diameter of 11.3 mm and an outer diameter of the rising portion 11c of 8.7 mm. In the rising portion 11c, four discharge holes 11x having a diameter of 1.0 mm were formed at equal intervals.
As the negative electrode current collector 6, a brass wire was formed into a nail shape having a predetermined size by press working, and the surface thereof was subjected to tin plating.
The negative electrode current collector 6 was electrically welded to the negative electrode terminal plate 11, the negative electrode current collector 6 was press-fitted into the through hole at the center of the resin sealing body 10, and the assembly sealing body 3 was attached to the negative electrode current collector 6.

(2) Production of insulating ring 4 A polypropylene plate having a thickness of 0.4 mm is punched to have an outer diameter of 12.8 mm, an inner peripheral surface of a regular octagon, and the diameter of the inscribed circle of the regular octagon is 8.7 mm. An insulating ring 4 shown in FIG.

(3) Assembly of alkaline battery 1 Each power generation element and alkaline electrolyte (40 wt% potassium hydroxide aqueous solution) are stored in a battery case 2, and an assembly sealing body 3 is attached to the opening of the battery case 2 to install a unit cell. Produced. An insulating ring 4 was attached to the unit cell, and an exterior seal 5 was further attached and heated with hot air to produce 2000 AA alkaline batteries 1 (LR6).

(Example 2)
Two thousand AA alkaline batteries 1 (LR6) were produced in the same manner as in Example 1 except that the insulating ring 16 shown in FIG. 2A was used in place of the insulating ring 4. The insulating ring 16 is produced by punching a polypropylene plate having a thickness of 0.4 mm, and has an outer diameter of 12.8 mm and an inner peripheral surface of a regular hexagon. The diameter is 8.7 mm.

(Example 3)
2,000 AA alkaline batteries 1 (LR6) were produced in the same manner as in Example 1 except that the insulating ring 17 shown in FIG. 2B was used instead of the insulating ring 4. The insulating ring 17 is produced by stamping a polypropylene plate having a thickness of 0.4 mm. The inner peripheral surface has a square shape, and the portion corresponding to the apex angle has an arc shape with a radius of 4.8 mm. The diameter of the inscribed circle of the square is 8.7 mm.

Example 4
Two thousand AA alkaline batteries 1 (LR6) were produced in the same manner as in Example 1 except that the insulating ring 18 shown in FIG. 2C was used instead of the insulating ring 4. The insulating ring 18 is formed by alternately forming 16 positioning portions 18a and 16 gap forming portions 18b on the inner peripheral surface. The length of the perpendicular drawn from the apex of one gap forming part 18b to a straight line connecting the apexes of the two positioning parts 18a on both sides of the gap forming part 18b is 0.5 mm. The diameter of the circle inscribed at the apexes of the 16 positioning portions 18a is 8.7 mm.

(Comparative Example 1)
2000 AA alkaline batteries (LR6) were produced in the same manner as in Example 1 except that the conventional insulating ring 20 shown in FIG. 3A was used in place of the insulating ring 4. The insulating ring 20 is a circle whose inner peripheral surface shape has a diameter of 8.7 mm. FIG. 3 is a plan view schematically showing the configuration of the insulating rings 20, 21, 22 used in the comparative example.

(Comparative Example 2)
2000 AA alkaline batteries (LR6) were produced in the same manner as in Example 1 except that the insulating ring 21 shown in FIG. The insulating ring 21 is a circle whose inner peripheral surface shape has a diameter of 9.0 mm.

(Comparative Example 3)
2,000 AA alkaline batteries (LR6) were produced in the same manner as in Example 1 except that the insulating ring 22 shown in FIG. The insulating ring 22 is a circle having a diameter of 8.7 mm in the inner peripheral surface region, and has a rectangular parallelepiped protrusion 22a extending from the inner peripheral surface of the insulating ring 22 to the axial center by a length of 0.5 mm. Three are provided at intervals. The diameter of the circle inscribed in the three protrusions 22a is 7.7 mm.

<Evaluation of productivity>
In Examples 1 to 3 and Comparative Examples 1 to 3, when 2000 AA alkaline batteries (LR6) were manufactured, the mounting state of the insulating rings 4, 16, 17, 18, 20, 21, 22 was changed. The number of “no insulation ring” and “center deviation” was examined visually. “No insulation ring” is a process of attaching the insulation rings 4, 16, 17, 18, 20, 21, 22, and the insulation rings 4, 16, 17, 18, 20, 21 due to interference with the negative electrode terminal plate 11. Insulation rings 4, 16, 17, 18, 20, 21, 22 are attached to the final product due to jumping of 22 and 22 and dropping of insulation rings 4, 16, 17, 18, 20, 21, 22 due to vibration. Indicates no state. Further, “center deviation” means that the insulating rings 4, 16, 17, 18, 20, 21, 22 are not attached to the predetermined positions of the negative electrode terminal plate 11, and the insulating rings 4, 16, 17, 18, 20 , 21, and 22 show a state where a part of the convex portion 11 b of the negative electrode terminal plate 11 rides on or near the top, or the end surface of the sealing portion of the battery case 2 is exposed. Table 1 shows the number of occurrences (pieces) and the defect rate (%) for each item.

From Table 1, it is clear that in Examples 1 to 4, neither “no insulation ring” nor “center shift” occurred, and the insulation rings 4, 16, 17, and 18 can be mounted satisfactorily.
Comparative Example 1 is configured to press-fit the negative terminal plate 11 having an outer diameter of the convex portion 11b of 8.7 mm into the inner peripheral surface region (circle having a diameter of 8.7 mm) of the insulating ring 20. For this reason, when the insulating ring 20 was mounted, “no insulating ring” occurred due to the repulsion of the insulating ring 20 against the negative electrode terminal plate 11. In addition, the insulation ring 20 was not horizontally mounted due to the resistance at the time of press-fitting, and “center shift” occurred.

In Comparative Example 2, the rising portion 11c of the negative electrode terminal plate 11 and the inner peripheral surface of the insulating ring 21 are not in contact with each other. For this reason, after the insulation ring 21 was mounted, the insulation ring 21 jumped off due to mechanical vibration, conveyance, etc., and “no insulation ring” occurred. Further, a “center shift” occurred out of the predetermined position.
Comparative Example 3 has a configuration in which three protrusions 22 a are provided at equal intervals on the inner peripheral surface of the insulating ring 22. In this configuration, positioning was insufficient and “no insulation ring” occurred. Further, “center shift” occurred without being in a predetermined position. In addition to the number of occurrences in Table 1, 11 were found where the protrusions 22a were bent. This can damage the appearance.

In the present embodiment, the case where the diameter of the inscribed circle with respect to the inner peripheral surface shape of the insulating rings 4, 16, 17, 18 matches the outer diameter of the convex portion 11 b of the negative electrode terminal plate 11 is shown. However, the present invention is not limited to this. For example, if the difference between the diameter of the inscribed circle and the outer diameter of the convex portion 11b is about 0.3 mm or less, the same effect as when the diameter of the inscribed circle and the outer diameter of the convex portion 11b match. Is obtained.
For example, when the diameter of the inscribed circle is larger than the outer diameter of the convex portion 11b, if the difference is 0.3 mm or less, the deviation generated in the manufacturing process is within a slight range that is acceptable in terms of function and appearance. In addition, since at least two positioning portions 12, 16a, 17a, and 18a that are contact surfaces between the insulating rings 4, 16, 17, and 18 and the negative terminal plate 11 appear, the insulating rings 4, 16, 17, and 18 Positioning becomes possible. Even when the diameter of the inscribed circle is smaller than the outer diameter of the convex portion 11b, if the difference is 0.3 mm or less, the negative electrode terminal plate 11 is connected to the inner peripheral surface region of the insulating rings 4, 16, 17, and 18. Since the positioning portions 12, 16a, 17a, and 18a provided on the inner peripheral surfaces of the insulating rings 4, 16, 17, and 18 are not local projections even if press-fitted into the insulating rings 4, 16, 17, and 18, the insulating rings 4, 16, 17, and 18 It is difficult to cause deformation, and the negative terminal plate 11 can be smoothly press-fitted.

<Reliability evaluation>
Next, the reliability of the alkaline dry battery 1 of Examples 1 to 3 and the alkaline dry battery of Comparative Example 1 was evaluated as follows.
A cresol red reagent for detecting an alkaline electrolyte is dissolved in a mixed solvent of water and alcohol in a 1: 1 (weight ratio) so that the concentration becomes 0.1% by weight, and this solution is applied to a commercially available A3 copy paper. And dried to produce a yellow test paper.
One test battery is fixed to the end of the short side of the test paper, and it is continuously charged with a current of 100 mA using a constant current generator, and gas is generated inside the test battery to form a thin portion of the resin sealing body 10. 10a was broken and the scattering state of the alkaline electrolyte was examined. When the alkaline electrolyte is attached to the test paper, the color of the test paper changes from yellow to purple, so that the scattering state of the alkaline electrolyte can be accurately grasped. The distance from the top of the convex portion 11b of the negative electrode terminal plate 11 in the test battery to the position where the alkaline electrolyte was scattered farthest was measured as the maximum scattering distance and compared. The comparison was performed for each of the alkaline dry batteries 1 of Examples 1 to 3 and the five alkaline dry batteries of Comparative Example 1, and the average value of the maximum scattering distance was obtained. The results are shown in Table 2.
FIG. 4 is a plan view showing the alkaline electrolyte 1 of Example 1 and the alkaline battery of Comparative Example 1 in a reduced state of the scattering state of the alkaline electrolyte on the test paper. 4A shows the scattering state of Example 1, and FIG. 4B shows the scattering state of Comparative Example 1.

In Examples 1 to 4, gaps 14, 16c, 17c, and 18c are provided in which the inner peripheral surfaces of the insulating rings 4, 16, 17, and 18 and the rising portion 11c of the negative electrode terminal plate 11 do not contact each other. When the gas pressure inside the alkaline battery 1 exceeds a predetermined value and the thin portion 10a of the resin sealing body 10 is broken, the gaps 14, 16c, 17c, and 18c are provided so that the gas and the alkaline electrolyte can be used without any obstacles. It is smoothly discharged to the outside, and in particular, the alkaline electrolyte does not spray far away in the form of a spray. Therefore, it is clear that the maximum scattering distance of the alkaline electrolyte is as short as less than 10 cm, and the gaps 14, 16c, 17c, and 18c can effectively function as gas vents.
On the other hand, in the comparative example 1, the inner peripheral surface of the insulating ring 20 and the surface of the rising portion 11c of the negative electrode terminal plate 11 are in contact with each other, and the gas pressure in the battery is increased until the contact state is released. Go up. Therefore, the gas pressure in the battery becomes higher than necessary, and the alkaline electrolyte is sprayed out and scattered farther. Therefore, the maximum scattering distance of the alkaline electrolyte is about 40 cm.

  The alkaline dry battery of the present invention has excellent productivity and reliability, and can be suitably used as a power source for portable devices and the like.

It is drawing which shows the structure of the alkaline dry battery which is 1st Embodiment of this invention. Fig.1 (a) is a longitudinal cross-sectional view which shows the structure of the principal part of an alkaline battery. FIG. 1B is a plan view showing a state in which the insulating ring 4 is mounted on the negative terminal plate 11. It is a top view which shows typically the structure of the insulation ring of another form. It is a top view which shows typically the structure of the insulating ring used by a comparative example. It is a top view which reduces and shows the scattering state of the alkaline electrolyte on a test paper about the alkaline dry battery of Example 1 and Comparative Example 1. FIG. It is a front view which shows typically the structure of the conventional AA alkaline battery. It is a longitudinal cross-sectional view which expands and shows the structure of the principal part of the alkaline dry battery shown in FIG. It is a longitudinal cross-sectional view which shows the structure of the principal part in the conventional alkaline dry battery of another form typically and expanded.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Alkaline battery 2 Battery case 3 Assembly sealing body 4,16,17,18 Insulation ring 5 Exterior label 6 Negative electrode collector 10 Resin sealing body 10a Thin part 11 Negative terminal board 11a Eave part 11b Convex part 11c Standing part 11x Gas discharge Hole 12, 16a, 17a, 18a Positioning part 13, 16b, 17b, 18b Air gap forming part 14, 16c, 17c, 18c Air gap part

Claims (7)

A battery case having an opening and accommodating a power generation element;
The battery case includes an outer label provided in contact with the outer peripheral surface of the battery case, a resin sealing body having a thin portion that is broken by the gas pressure inside the battery case, and a negative electrode terminal plate formed with a gas discharge hole. An assembled sealing body that is mounted to form a sealing portion;
A ring-shaped member that is mounted on the negative electrode terminal plate so that at least a part of the inner peripheral surface is in contact with the surface of the negative electrode terminal plate, and is sandwiched between the opening end portion of the battery case and the end portion of the exterior label on the battery case opening side An alkaline battery comprising an inner ring and an insulating ring provided with a positioning portion that contacts the surface of the negative electrode terminal plate and a void forming portion that forms a void portion for degassing together with the negative electrode terminal plate surface.   The alkaline dry battery according to claim 1, wherein a plurality of positioning portions and gap forming portions are alternately provided on the inner peripheral surface of the insulating ring.   The alkaline dry battery according to claim 1 or 2, wherein the shape of the gap portion in a direction perpendicular to the axis of the insulating ring is V-shaped, U-shaped or I-shaped.   The alkaline dry battery according to any one of claims 1 to 3, wherein a shape of a region surrounded by an inner peripheral surface of the insulating ring in a direction perpendicular to the axis of the insulating ring is a polygon.   The alkaline dry battery according to claim 4, wherein the shape of the region surrounded by the inner peripheral surface of the insulating ring in a direction perpendicular to the axis of the insulating ring is a regular n-gonal shape where n is an integer of 6 or more.   The shape of the region surrounded by the inner peripheral surface of the insulating ring in the direction perpendicular to the axis of the insulating ring is a regular m-gon with m being an integer of 4 or more, and corresponds to the apex angle of the regular m-gon. The alkaline dry battery according to claim 4, wherein the portion has a shape formed in an arc shape.   The alkaline dry battery according to claim 1, wherein a plurality of notches are provided on the inner peripheral surface of the insulating ring.

Images