JPH0537423Y2 - - Google Patents

Description

[Detailed Description of the Invention] <<Industrial Application Field>> This invention relates to an improvement of a cylindrical dry battery using a zinc can as the negative electrode.

<<Prior Art>> A typical conventional structure of this type of cylindrical dry battery is shown in FIG. In this dry battery, a separator 12 containing an electrolyte is disposed in close contact with the inner surface of a bottomed cylindrical negative electrode zinc can 10, and a positive electrode mixture 14 is loaded inside the separator 12. A flange paper 16 is arranged on the upper surface of the positive electrode mixture 14, and a carbon rod 18 is inserted into the center of the positive electrode mixture 14.

The upper end opening of the negative electrode zinc can 10 is closed with a sealing gasket 20 made of synthetic resin, and the carbon rod 18 is tightly fitted into the center hole of the sealing gasket 20 and passes through it. An adhesive sealant 22 such as pitch is applied to the interface between the inner periphery of the center hole of the sealing gasket 20 and the carbon rod 18 to seal this area. Further, the outer circumferential surface of the negative electrode zinc can 10 and the upper surface periphery of the sealing gasket 20 are covered with a heat-shrinkable tube 24, and the joints between the two are sealed.

Further, a hat-shaped positive terminal plate 26 is placed over the protruding end of the carbon rod 18 and the upper surface of the sealing gasket 20, and this positive terminal plate 26 is covered with an insulating washer 2.
8, it is pressed down from above by the curled upper end of the metal outer can 30.

<<Problem to be solved by the invention>> The above-mentioned flange paper 16 covers the upper surface of the positive electrode mixture 14,
This is to prevent the positive electrode mixture 14 from chipping or losing its shape. The flange paper 16 has a donut plate shape, and the inner diameter of its center hole is approximately equal to the outer diameter of the carbon rod 18, and the outer diameter of the flange paper 16 is slightly smaller than the inner diameter of the negative electrode zinc can 10. Therefore, the outer periphery of the flange paper 16 is almost in contact with the separator 12 on the inner surface of the negative electrode zinc can 10.

By the way, in a dry cell, electrolyte overflows inside as the discharge progresses, but in the conventional dry cell described above, the overflowing electrolyte flows into the cardboard flange 16.
This area is particularly rich in electrolyte. In areas where the electrolyte is rich, the discharge reaction is more active than in other areas, and the active material is consumed more than in other areas. Therefore, when the depth of discharge becomes deeper, the negative electrode zinc can 10 facing the peripheral part of the flange paper 16 rich in electrolyte is extremely consumed, and in this part the zinc can 10
This may cause holes to form and cause external leakage.

This idea was created in view of the above-mentioned conventional problems, and provides a dry battery with excellent leakage resistance that is less prone to external leakage caused by the flange paper containing a large amount of overflowing electrolyte. There is a particular thing.

<Means for solving the problem> Therefore, in this invention, the outer diameter of the flange paper is made smaller than the inner diameter of the negative electrode zinc can, and the separator on the inner surface of the negative electrode zinc can is spaced from the outer periphery of the flange paper. The electrolyte contained in the flange paper was prevented from directly acting on the negative electrode zinc can.

《Operation》 Since there is a sufficient distance between the separator and the outer periphery of the flange paper, even if the flange paper contains a large amount of overflowing electrolyte, the electrolyte contained therein will not damage the negative electrode zinc can locally. This does not cause wear and tear, and external leakage caused by this can be prevented.

<<Example>> FIG. 1 shows the structure of a dry battery according to an example of this invention. The basic structure is the same as the conventional example shown in FIG.
A positive electrode mixture 14 containing manganese dioxide as an active material is filled into the negative electrode zinc can 10 via a donut plate-shaped flange paper 32 placed on the top surface of this positive electrode mixture 14, and this flange paper 32. The carbon rod 18 inserted into the center of the positive electrode mixture 14 through the carbon rod 18
and a sealing gasket 20 that protrudes from the center and closes the upper end opening of the negative electrode zinc can 10. Also, a sealant 22, a heat-shrinkable tube 24, a positive terminal plate 2
6. The configurations of the insulating washer 28 and the outer can 30 are also the same as those of the prior art.

Tsuba paper 32 in the one of the present invention shown in Fig. 1
differs from the conventional flange paper 16 shown in FIG. 2, its outer diameter is sufficiently smaller than the inner diameter of the negative electrode zinc can 10;
Separator 12 and flange paper 3 on the inner surface of negative electrode zinc can 10
A sufficient gap a is provided between the outer periphery of No.2. This is a feature of the present invention. For example, in the case of a single type dry battery, this gap a is set to be approximately several mm.

As the discharge progresses, the electrolytic solution overflows and is absorbed by the cardboard flange 32, so that the area very close to the flange paper 32 becomes a very rich area of electrolyte. However, since a sufficient gap a is provided between the outer periphery of the flange paper 32 and the separator 12, the electrolyte contained in the flange paper 32 does not directly act on the negative electrode zinc can 10. Therefore, unlike the conventional case, the negative electrode zinc can 10 is not locally severely consumed in this portion.

<<Effects of the invention>> As explained in detail above, in the dry cell according to this invention, the electrolyte overflows as discharge progresses and is absorbed by the lining paper, which locally wears out the negative electrode zinc can. This is not the cause, and external leakage at the end of discharge that occurs due to this can be eliminated.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional view showing a sealing structure for a dry cell battery according to an embodiment of the present invention, and FIG. 2 is a partial cross-sectional view showing a sealing structure for a conventional dry cell battery. 10...Negative electrode zinc can, 12...Separator, 1
4... Positive electrode mixture, 16... Flange paper (conventional), 18...
... Carbon rod, 20 ... Sealing gasket, 32 ... Flange paper (this invention), a ... Flange paper 32 and separator 12
the gap created between.

Claims (1)

[Scope of utility model registration request] A cylindrical negative electrode zinc can with a bottom, a separator containing an electrolyte disposed in close contact with the inner surface of the negative electrode zinc can, a positive electrode mixture filled into the negative electrode zinc can via the separator, and the negative electrode zinc can. A donut plate-shaped flange paper placed on the top surface of the positive electrode mixture, a carbon rod inserted through the flange paper into the center of the positive electrode mixture, and a carbon rod protruding from the center to form the negative electrode. In a dry battery equipped with a sealing gasket that closes the upper end opening of the zinc can, the outer diameter of the flange paper is smaller than the inner diameter of the negative electrode zinc can, and the separator on the inner surface of the negative electrode zinc can and the outer periphery of the flange paper 1. A dry battery characterized in that the electrolytic solution contained in the flange paper does not directly act on the negative electrode zinc can by separating the space between the flange paper and the flange paper.