JPH0537408Y2 - - Google Patents

Description

[Detailed Description of the Invention] <<Industrial Application Field>> This invention relates to an alkaline battery, and in particular to a structure that improves workability when filling the inside of a separator with a zinc negative electrode.

<Prior Art> The manufacturing procedure for alkaline batteries is to fill the peripheral part of a cylindrical case with a bottom with a positive electrode mixture, then load a separator into the central hole of the positive electrode mixture, and then fill the inside of the separator with the positive electrode mixture. After filling with zinc negative electrode, a current collector rod is inserted into the center of the zinc negative electrode, the opening of the case is hermetically sealed with a sealing gasket through which the current collector rod is inserted, and the negative electrode terminal plate is joined to the protruding end of the current collector rod. The battery is completed by fixing it on the case via a sealing gasket and finally applying an exterior cover.

The separator used in this type of alkaline battery is generally made of a 100-150 μm thick pulp-containing nonwoven fabric wound three to four times into a cylindrical shape with a bottom.

The reason why such a thin nonwoven fabric is wound multiple times is inevitably derived from consideration of the operability at the time of forming the tube, the electrolyte absorption ability of the separator itself, and the discharge performance of the battery.

《Problems that the invention aims to solve》 However, in reality, with this type of separator,
After the positive electrode mixture is loaded into the center hole, it swells due to liquid absorption, shrinks in diameter, and loses its shape retention. When the agent comes into contact with the protruding end from the surface of the separator, the protruding end may be bent or buckled. In this case, the protruding end may be caught inside the separator, and the The opening state of the separator tended to become unstable.

In such a state, the isolation between the positive and negative electrodes is insufficient, often causing internal short circuits, which has been a factor in reducing product yield.

Incidentally, noticeably bent items can be easily removed by initial voltage inspection, etc., but incompletely bent items may be overlooked, causing subsequent troubles.

In order to prevent this kind of trouble and improve yield, an auxiliary means is used to properly insert the jig into the opening of the separator at the time of inserting the jig. It causes a decline in sex.

This idea was created in view of the above problems, and its purpose is to structurally eliminate bending and buckling of the opening edges of the separator when filling with zinc negative electrodes. It is an object of the present invention to provide an alkaline battery that improves workability and yield and prevents various troubles associated with bending and buckling.

<<Means for Solving the Problems>> In order to achieve the above object, this invention includes a positive electrode mixture filled in the periphery of the case, a separator loaded in the central hole of the positive electrode mixture, In an alkaline battery comprising a zinc negative electrode filled inside the separator and an opening of the case hermetically sealed with a sealing gasket, the separator is made of a nonwoven fabric made of vinylon pulp or a mixture of rayon and pulp. The gist is that the material is wound in a plurality of layers to form a bottomed cylindrical shape, and the periphery of the opening end is hardened into an annular shape.

[Operation] According to the above configuration, the opening edge does not swell or contract in diameter due to liquid absorption by the separator, and the original shape is maintained, so there is no bending or buckling of the opening edge when inserting the jig. , and does not require any auxiliary means to prevent bending or buckling.

<<Example>> Hereinafter, an example of this invention will be described in detail using the drawings.

In FIG. 1, 1 is a battery case, 2 is a negative electrode current collector rod that protrudes through the center of the battery case 1, and a zinc negative electrode 3, a separator 4, and a positive electrode mixture are arranged around the periphery of this current collector rod 2. 5 are arranged concentrically.

Then, a sealing gasket 6 having the current collector rod 2 penetrated through the center thereof is fitted into the opening of the battery case 1, and a negative electrode terminal plate 7 connected to the current collector rod 2 is held in the inner periphery of the upper surface thereof. By caulking the opening periphery of the battery case 1, the inside of the battery is hermetically sealed.

The sealing gasket 6 is an injection molded body of synthetic resin such as polypropylene, polyethylene, nylon, etc., and includes a boss portion 6b formed around an insertion hole 6a through which the current collector rod 2 is inserted, and a boss portion 6b.
A flange portion 6c integrally connected to the periphery of
It consists of d.

A thin wall portion 6e for gas venting is formed in an annular shape on the lower surface of the flange portion 6c. and facing the zinc negative electrode 3.

The separator 4 is made by winding a 120 μm thick rectangular separator base paper made of vinylon nonwoven fabric containing 15% mercerized pulp three times to form a cylindrical shape, as shown in FIG. The upper opening edge 4a is heated and compressed to form an annular hardened portion 8. Since the vinylon component in the nonwoven fabric is thermoplastic, the hardened portion 8 is melted by heating and compression and solidified by cooling. Form.

If the non-woven fabric contains more than 20% of a non-thermoplastic material such as pulp, the curing by heating and compression will be insufficient, and in this case, the non-woven fabric will not be cured sufficiently by the heating and compression process. It is also possible to apply a substance, such as an adhesive, that does not easily swell with the electrolytic solution and harden the layers into an integrated state.

In the above configuration, in order to assemble the battery, the cylindrical positive electrode mixture 5 is first filled in the periphery of the battery case 1, and then the separator 4 is loaded into the hole formed in the center of the positive electrode mixture 5. As shown in FIG. 3, the zinc negative electrode 3 is filled using a filling jig 9.

At this time, in the case of the conventional separator which does not have the hardened portion 8 described above, it swells due to impregnation with the electrolytic solution, and its opening edge 4a contracts in diameter, and when the jig 9 is pushed in in this state, the opening edge The edge 4a may easily bend or buckle, and be pulled into the opening as shown by the imaginary line in FIG. Since the shape is maintained and the diameter is not reduced, bending or buckling of this type due to the insertion of the jig 9 is extremely reduced.

After the filling operation is completed, the sealing gasket 6 is fitted into the opening of the battery case 1, and the periphery is caulked with the negative electrode terminal plate 7 wrapped around the inner periphery of the upper surface. In the mated state, the opening edge 4a of the separator 4 is reduced in diameter along the tapered shape of the lower surface of the flange portion 6c, and comes into contact with the peripheral edge of the boss portion 6b at the center of the lower surface of the sealing gasket 6.

At this time, the hardened portion 8 is difficult to flexibly deform;
By pressure welding, the shape follows the taper of the lower surface of the flange portion 6c, and in that state, the zinc negative electrode 3 is attached to the separator 4.
It is maintained completely separated from the outer circumferential portion including the thin wall portion 6e via the thin wall portion 6e.

<<Effects>> As explained in detail using the examples above, in this invention, the opening edge of the separator does not swell or contract due to liquid absorption, and shape retention is maintained, so it is easy to use when inserting the jig. There is no bending or buckling of the opening edge, and the positive and negative electrodes can be well isolated without requiring any auxiliary means to prevent bending or buckling.

Therefore, this invention not only improves workability and product yield, but also prevents various post-manufacturing problems caused by bending or buckling of the opening edge of the separator.

[Brief explanation of the drawing]

FIG. 1 is a partially enlarged partial sectional view showing the sealing structure of an alkaline battery according to this invention, FIG. 2 is a perspective view of a separator, and FIG. 3 is a sectional view showing the filling operation of a zinc negative electrode into the inside of the separator. 1... Battery case, 3... Zinc negative electrode, 4... Separator, 4a... Opening edge, 5... Positive electrode mixture,
6... Sealing gasket, 8... Annular hardened part, 9
...Zinc negative electrode filling jig.

Claims (1)

[Scope of claims for utility model registration] (1) A positive electrode mixture filled in the periphery of the case,
In an alkaline battery comprising a separator loaded into the central hole of the positive electrode mixture and a zinc negative electrode filled inside the separator, the opening of the case is hermetically sealed with a sealing gasket, the separator comprising: , is characterized in that it is made by winding a nonwoven fabric made of vinylon pulp or a mixture of rayon and pulp in multiple layers to form a bottomed cylinder shape, and the peripheral edge of the open end of the nonwoven fabric is hardened into an annular shape. alkaline battery. (2) The alkaline battery according to claim 1, wherein the curing is performed by heating and compression. (3) The alkaline battery according to claim 1, wherein the curing is performed by applying a substance, such as a synthetic resin, that does not swell with respect to the electrolytic solution.