JPH05198291A - Sealed alkali battery - Google Patents

Abstract

PURPOSE:To provide long-time reliability for the leak prevention of electrolyte in an sealed alkali battery used for various electrical equipment. CONSTITUTION:The opening upper edge of a case 32 and a metal cap plate 33 provided with a cap-shaped terminal 31 are sealed together by laser beam welding. An elastic valve 35 is stored in the cap-shaped terminal 31 and spot- welded to a hollow rivet 34. The cap plate 33 is caulked with the hollow rivet via an insulating gasket 36 and a washer 37. An alkalinity-resistant packing with rubber elasticity is arranged both or either between the hollow rivet 34 and the gasket 36 and/or between the gasket 36 and the washer 37 to allow excellent leak prevention of electrolyte.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alkaline sealed battery in which a battery element such as an alkaline electrolyte and a positive and negative electrode plate is housed in a metal container and which has an exhaust mechanism.

[0002]

2. Description of the Related Art In recent years, many kinds of batteries have been widely used as a main power source and a backup power source with the miniaturization and portability of electric devices, and in particular, alkaline sealed batteries have been widely used.

Among the alkaline sealed batteries, there is known one having a restoring type exhaust mechanism in which an elastic valve body is press-fitted in a cap-shaped terminal. A conventional alkaline sealed battery will be described below with reference to FIG.

In FIG. 6, reference numeral 31 denotes a cap provided on a metal lid plate 33 that seals the upper edge of the opening of a square bottomed metal case 32 that houses battery elements such as alkaline electrolyte and positive and negative electrode plates. Shaped terminals. The peripheral portion of the metal lid plate 33 is welded to the upper edge of the opening of the rectangular bottomed metal case 32 by laser beam welding to form the bottomed metal case 32.
Is sealed. As shown in FIG. 6 (b), the details of the cap-shaped terminal are provided with exhaust holes 31 a on the sides, and the enlarged flange portion 31 b at the lower end is spot-welded to the upper edge portion 34 a of the hollow rivet 34. Hollow rivet 3
4, the elastic valve body 35 made of synthetic rubber is stored under pressure in the space formed by the upper edge portion 34a and the cap-shaped terminal 31.
The lower end portion 34c at the lower end of the central through hole 34b is expanded outwardly, so-called caulking is performed with the upper edge portion 34a, and the metallic lid plate 33 and the washer 37 are sandwiched via the synthetic resin gasket 36. is doing. The lower end of the washer 37 is bent downward and spot-welded to the positive electrode lead of the battery element.

The sealed battery as shown in FIG. 6 is often an alkaline storage battery using nickel oxide or manganese oxide as the positive electrode active material and cadmium, hydrogen, zinc, iron or the like as the negative electrode active material. .. And, the electrolyte solution of potassium hydroxide or sodium hydroxide used in this alkaline storage battery has extremely high leak property,
In alkaline storage batteries, sealing technology for preventing leakage of electrolyte is extremely important.

[0006]

However, in the above-mentioned conventional configuration, the hollow rivet is used for caulking. However, if the caulking alone is used for a long period of time when an alkaline electrolyte having a high leak property is used. There is a problem in that the leakage of the electrolyte solution is not sufficiently prevented.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide an alkaline sealed battery capable of ensuring long-term reliability in preventing leakage of an alkaline electrolyte.

[0008]

To achieve this object, the present invention provides an alkali-resistant and rubber-elastic packing between the hollow rivet and the gasket and / or between the gasket and the washer. is there.

[0009]

With this structure, when the hollow rivet is caulked, the repulsive elasticity of the packing significantly improves the adhesion,
An excellent effect of preventing leakage of the electrolytic solution can be obtained.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. An ethylene propylene terpolymer was used as the material having rubber elasticity.

(Embodiment 1) FIG. 1 is a cross-sectional view of an essential part of a cap-shaped terminal portion of an alkaline sealed battery according to Embodiment 1 of the present invention.
FIG. 2 is a half cut sectional view of the hollow rivet in the first embodiment of the present invention, and FIG. 3 is a half cut sectional view of the washer in the first embodiment of the present invention. In FIG. 2, 34d is packing provided on the hollow rivet, and 37a in FIG. 3 is packing provided on the washer. The configuration of other parts is the same as that of the conventional example shown in FIG.

(Embodiment 2) FIG. 4 is a cross-sectional view of an essential part of a cap-shaped terminal portion of an alkaline sealed battery according to Embodiment 2 of the present invention. The difference from the configuration of the first embodiment is that only the hollow rivet 34 is provided with the packing 34d, and the washer 37 is not provided with the packing.

(Embodiment 3) FIG. 5 is a cross-sectional view of a main part of a cap-shaped terminal portion of an alkaline sealed battery according to a third embodiment of the present invention. 37 is different from the configurations of the first and second embodiments.
The packing 37a is provided only on the washer and the hollow rivet 34 is not provided with packing.

A nickel-cadmium storage battery was constructed by the examples according to the present invention and the conventional examples, and a comparative test of leakage resistance was conducted. This leak resistance test was conducted at a temperature of 35 ° C. and a humidity of 8
It was stored at a constant temperature and constant humidity of 5 to 90%, and a pH test paper was applied to the periphery of the seal part of the lid plate every 30 days to confirm the presence or absence of an alkaline reaction.

The following table shows the results of a comparative experiment of liquid leakage resistance.

[0016]

[Table 1]

As is clear from (Table 1), the alkaline sealed batteries according to the examples of the present invention have an excellent effect in terms of liquid leakage resistance.

The leakage rate of the alkaline sealed battery according to the embodiment of the present invention is lower than that of the conventional alkaline sealed battery, because the alkaline sealed battery according to the embodiment of the present invention has a space between the hollow rivet and the gasket and between the gasket and the washer. This is because the adhesiveness is remarkably improved by the packing having alkali resistance and rubber elasticity in both or one of them.

[0019]

As described above, according to the present invention, by providing a packing having alkali resistance and rubber elasticity between the hollow rivet and the gasket and / or between the gasket and the washer, the leak of the alkaline electrolyte is obtained. It is possible to realize an excellent alkaline sealed battery capable of ensuring long-term reliability for prevention.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part of a cap-shaped terminal portion of an alkaline sealed battery according to a first embodiment of the present invention.

FIG. 2 is a half cut sectional view of the hollow rivet.

FIG. 3 is a half cutaway view of the washer.

FIG. 4 is a sectional view of an essential part of a cap-shaped terminal portion of an alkaline sealed battery according to a second embodiment of the present invention.

FIG. 5 is a sectional view of an essential part of a cap-shaped terminal portion of an alkaline sealed battery according to a third embodiment of the present invention.

FIG. 6A is a perspective view showing the external appearance of a conventional prismatic alkaline sealed battery, and FIG. 6B is an enlarged cross-sectional view of the same main part.

[Explanation of symbols]

 31 Cap Terminal 31a Exhaust Hole 31b Enlarged Collar Part 32 Case 33 Cover Plate 34 Hollow Rivet 34a Upper Edge 34b Central Through Hole 34c Lower End 34d Packing on Hollow Rivet 35 Elastic Valve Body 36 Gasket 37 Washer 37a Provided on Washer packing

Claims (3)

[Claims] 1. A lid plate having a through hole portion, a hollow rivet having a terminal cap for fixing an elastic valve body mounted on its head, and a gasket arranged in the through hole portion for insulating the hollow rivet from the lid plate. A sealed battery using an alkali as an electrolytic solution, which has a sealed structure consisting of a washer arranged at the lower end of the hollow rivet and caulking and fixing the hollow rivet to the lid plate through the gasket, An alkaline sealed battery in which a packing having alkali resistance and rubber elasticity is provided between the hollow rivet and the gasket and / or between the gasket and the washer. 2. An alkali sealed battery according to claim 1, wherein the packing having an alkali resistance and rubber elasticity has a sheet shape. 3. An alkaline sealed battery in which the alkali-resistant and rubber-elastic packing according to claim 1 is formed by coating or pasting on both or one of the surfaces of the hollow rivet and washer.