JPH087865A - Cylindrical alkaline battery - Google Patents

Abstract

(57) [Summary] [Object] To provide a cylindrical alkaline battery having a sealing structure provided with an explosion-proof mechanism that functions stably even at high temperature and high pressure. [Structure] A notch is formed in a part of the metal washer 12, and the metal washer 12 is bent toward the gasket 7 side to form a gas escape hole 11,
Moreover, since the bent portion tip 16 is provided close to the annular connecting portion 5 of the gasket 7, even when the battery temperature rises and the battery internal pressure rises, the amount of expansion of the annular connecting portion 5 of the gasket 7 increases. Therefore, the annular thin portion 6 becomes thinner and can be reliably broken by the internal pressure of the battery, and gas escapes to the outside of the battery, so that the battery does not burst and the explosion-proof mechanism functions stably.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing structure for a cylindrical alkaline battery.

[0002]

2. Description of the Related Art Alkaline dry batteries, which are one of the tubular alkaline batteries, are batteries that are short-circuited in the state where one or more batteries are connected in series, or when they are used in equipment with the wrong polarity. There has been a problem that a strong gas generating reaction occurs inside and the battery bursts.

Conventionally, in order to solve this problem,
Various sealing structures having an explosion-proof mechanism have been studied for alkaline batteries (for example, Japanese Utility Model Laid-Open No. 59-152664). The typical sealing structure will be specifically described with reference to the drawings.

FIG. 3 is a half-cut sectional view of a conventional alkaline dry battery. A positive electrode mixture 2 made of manganese dioxide and graphite is molded into a cylindrical shape and inserted into a battery case 1, and a negative electrode gel-like substance 3 made of caustic potash, a viscous substance and zinc is injected through the separator 4 into the inside. Then, the resin gasket 7 having the annular connecting portion 5 and the annular thin portion 6, the negative electrode current collector 8, the negative electrode terminal bottom plate 10 having the gas escape hole 9, and the metal washer 12 having the gas escape hole 11 are integrated. The inserted part is inserted into the opening 13 of the battery case 1, and the opening 1
It is hermetically sealed by bending 3 inside. The positive electrode terminal 14 is fixed to the bottom of the battery case 1 by welding, and the outer peripheral side surface of the battery is covered with an outer label 15.

In the alkaline dry battery constructed as described above, when gas is generated inside the battery and the pressure in the battery case 1 rises above a certain pressure, the annular thin portion 6 of the resin gasket 7 is broken, Gas escapes from the part. The escaped gas passes through the gas escape hole 11 of the metal washer 12 and is discharged to the outside of the battery from the gas escape hole 9 of the negative electrode terminal bottom plate 10, and the internal pressure of the battery case 1 is reduced to prevent the battery from bursting. .

[0006]

However, in the above configuration, when the circuit is short-circuited in the state where one or more batteries are connected in series, the internal temperature of the battery itself is increased by the current flowing in the short-circuit. Rapidly rises, the resin gasket softens due to the high temperature, and is deformed by the gas pressure generated inside the battery. At this time, since the annular connecting portion 5 of the gasket is curved and extends along the lower surface of the metal washer 12, the annular thin portion 6 is not broken. In such a case, the explosion-proof mechanism of the annular thin portion 6 of the resin gasket 7 does not function, and the battery has a problem of bursting.

FIG. 4 is an enlarged cross-sectional view of a sealing portion of a conventional alkaline dry battery, in which the temperature inside the battery becomes high, the resin gasket 7 is softened, and the ring-shaped connecting portion 5 is bent and expanded. Shows a state in which the annular thin portion 6 does not break even when the height increases.

The present invention solves the above problems.
An object of the present invention is to provide a highly reliable cylindrical alkaline battery having a stable explosion-proof mechanism.

[0009]

In order to achieve this object, the tubular alkaline battery of the present invention has a metal washer with a notch formed therein and bent toward the gasket to form a gas escape hole. The tip of the part is provided close to the annular connecting part of the gasket.

[0010]

With this configuration, when the internal pressure of the battery increases due to the gas generation due to the rapid increase in the internal temperature of the battery, a notch is made in a part of the metal washer and bent to the gasket side to form a gas escape hole, and Since the tip of the bent portion is provided close to the annular connecting portion of the gasket, the amount of expansion of the annular connecting portion of the gasket increases,
The explosion-proof mechanism capable of reliably breaking the annular thin-walled portion by the internal pressure of the battery can prevent the battery from bursting.

[0011]

EXAMPLES An example of the present invention will be described below.
FIG. 1 is a half sectional view of an alkaline dry battery according to an embodiment of the present invention. In the figure, make a cut in a part of the metal washer 12 and fold it to the gasket side to make a gas escape hole 1
1, except that the bent portion tip 16 is provided in the vicinity of the annular connecting portion of the gasket, and is the same as the conventional alkaline dry battery of FIG.

The alkaline dry battery constructed as described above generates gas when the internal temperature of the battery rapidly rises, such as when an external short circuit occurs when one or more batteries are connected in series. When the internal pressure of the battery rises, as shown in FIG. 2, the annular connecting portion 5 of the gasket makes a cut portion in a part of the metal washer 12 and bends to the gasket side to form the gas escape hole 11. In addition, since the bent portion tip 16 is provided close to the gasket annular connecting portion, the amount of expansion of the gasket annular connecting portion increases, so the annular thin portion becomes thinner and is reliably broken by the battery internal pressure. Can be made
Since the gas escapes to the outside of the battery, the battery does not burst.

Next, L using the metal washer of the present invention
In order to compare the safety of the R20 type battery and the conventional LR20 type battery, the following experiment was conducted for the purpose of forcibly increasing the pressure inside the battery.

When the circuit is short-circuited in a state where four pieces are connected in series, one set of four pieces is connected in reverse and a short circuit is made by connecting a resistance of 2.2Ω. The results of examining the presence or absence of battery rupture are shown in (Table 1).

[0015]

[Table 1]

As is clear from (Table 1), there are 14 sets of conventional batteries, in which four batteries are short-circuited in series and the explosion-proof mechanism does not operate and the battery bursts. In the experiment, no battery rupture was observed, and there was a remarkable effect on the stability of the explosion-proof mechanism.

[0017]

As described above, according to the present invention, a notch is formed in a part of a metal washer and bent toward the gasket to form a gas escape hole, and the bent tip is close to an annular connecting portion of the gasket. Since it is provided so that the expansion amount of the annular connecting portion of the gasket increases,
Explosion-proof mechanism that allows the annular thin-walled part to become thinner and can be reliably broken by the internal pressure of the battery, which can prevent the battery from bursting and is stable and reliable even when the battery temperature becomes high. It is possible to realize a cylindrical alkaline battery having an explosion-proof mechanism.

[Brief description of drawings]

FIG. 1 is a half sectional view of an alkaline dry battery according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a sealing portion of an alkaline dry battery according to an embodiment of the present invention.

FIG. 3 is a half-cut sectional view of a conventional alkaline battery.

FIG. 4 is an enlarged sectional view of a sealing portion of a conventional alkaline dry battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery case 2 Positive electrode mixture 3 Negative gel-like substance 4 Separator 5 Annular connecting part 6 Annular thin part 7 Resin gasket 8 Negative electrode current collector 9 Gas escape hole 10 Negative electrode terminal bottom plate 11 Gas escape hole 12 Metal washer 13 Opening Part 14 Positive electrode terminal 15 Exterior label 16 Tip of bent part provided on metal washer

Claims (1)

[Claims] 1. A battery case containing a power generating element, a resin gasket having an annular thin portion that closes an opening of the battery case and is broken by gas pressure, and a metal washer installed on the gasket. The gasket includes a holding portion for holding the current collector in a central portion, a side peripheral portion in close contact with the opening of the battery case, and an annular connecting portion connecting the holding portion and the side peripheral portion. And a gasket having an annular thin portion in a part of the annular connecting portion connected to the holding portion, wherein the metal washer is a gas escape hole in which a notch portion is bent to a gasket side, and A cylindrical alkaline battery, wherein the bent portion tip is provided in proximity to the annular connecting portion of the gasket.