JPH11329383A - Alkaline dry battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve safety by securing the operation of the explosion-proof mechanism of an alkaline dry battery. SOLUTION: When it is assumed that the distance from the outside wall of a boss part 10 in a resin sealing member 7 of an alkaline dry battery to the inside wall of the resin sealing member is (r) (mm), the bottom thickness of the resin sealing member 7 is T (mm), the thickness of a thin part 8 of the resin sealing member is (t) (mm), and the height from the bottom of the resin sealing member to a metal plate 6 is (h) (mm), a coefficient (k) expressed by an equation h=k×(r×T×t) is set to 3.73 or more and thereby, a vent hole of the metal plate 6 is prevented from being closed by the stretching of the bottom and the thin part of the resin sealing member 7 due to abnormal gas pressure and the explosion-proof mechanism is allowed to work properly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alkaline battery having an explosion-proof mechanism for preferentially destroying a thin portion provided in a resin sealing body by an increase in internal gas pressure.

[0002]

2. Description of the Related Art Conventionally, an alkaline dry battery has an explosion-proof function to prevent the battery from being ruptured due to the generation of an excessive gas when the battery is erroneously used or the like. That is, when the gas pressure in the battery rises to a predetermined pressure or more, the thin portion provided in the resin sealing body at the battery opening is broken preferentially, and the gas released therefrom comes out of the gas vent hole of the metal plate. The gas is quickly discharged from the gas discharge port on the negative electrode terminal plate to the outside of the battery.

[0003]

However, in the case of the battery having the above-mentioned conventional structure, the bottom of the resin sealing body and the thin portion provided on the bottom are stretched due to excessive gas generation to release the gas from the metal plate. The explosion-proof mechanism may not be operated by closing the hole, and the battery may be ruptured.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and prevents a situation in which a gas vent hole of a metal plate is closed due to extension of a bottom portion and a thin portion of a resin sealing body. An object of the present invention is to provide an alkaline dry battery having excellent safety by ensuring the operation of an explosion-proof mechanism.

[0005]

According to the present invention, an opening of a metal case is sealed by using a resin sealing body, and the resin sealing body has a boss portion in contact with a negative electrode current collector, a groove-shaped portion, and the like. In an alkaline dry battery having a bottom portion having a thin portion and a metal plate having a gas vent hole formed at a position above the bottom portion from the boss portion to the resin sealing inner wall, a resin sealing inner wall is formed from an outer wall of the boss portion. Is r (mm), the bottom thickness of the resin sealing body is T (mm), the thickness of the thin portion of the resin sealing body is t (mm), and the height from the bottom of the resin sealing body to the metal plate is h.
(Mm), the coefficient k represented by the following equation: h = k × (r × T × t) is not less than 3.73.

In the present invention, the reason why the coefficient k is set to 3.73 or more is based on a large number of experimental results obtained by changing the respective distances in the resin sealing body, as described in the following embodiments of the present invention. Things.

According to the present invention, even when an excessive gas is generated in the battery due to misuse or the like and the bottom and the thin portion of the resin sealing member are extended, the gas vent hole of the metal plate is not blocked.
Therefore, the inoperability of the explosion-proof mechanism can be prevented, and the safety of the battery is improved.

[0008]

FIG. 1 is a longitudinal sectional view of an AA cylindrical alkaline dry battery LR6 used in an embodiment of the present invention. In FIG. 1, 1 is a positive electrode mixture comprising manganese dioxide and graphite, 2 is a negative electrode gel zinc, 3 is a separator, 4 is a metal case, 5 is a negative electrode terminal plate, 6 is a metal plate, 7 is a resin sealing body, 8
Is a thin resin portion of the resin sealing body, 9 is a negative electrode current collector, and 10 is a boss portion of the resin sealing body. The resin sealing body 7, the metal plate 6 and the negative electrode terminal plate 5 are integrated with the negative electrode current collector 9.

As shown in the figure, the resin sealing body 7 has a groove-shaped thin portion 8 at the bottom thereof, which is ruptured due to an abnormal rise in internal gas pressure. The gas released from this goes out of the gas vent hole of the metal plate 6 and is discharged outside through the gas discharge port on the negative electrode terminal plate. As previously mentioned,
If the gas vent hole of the metal plate 6 is closed by the extension of the bottom portion and the thin portion of the resin sealing body, the explosion-proof mechanism will not operate normally.

As shown in FIG. 1, the thickness of the thin portion 8 is represented by t, and the distance from the outer wall of the boss to the inner wall of the resin seal is represented by r.
The bottom thickness of the resin sealing body was T, the height from the bottom of the resin sealing body to the metal plate 6 having two gas vent holes was h, and these were set as follows to manufacture a battery.

T: 0.15, 0.20, 0.25 (mm) r: 3.0, 3.5, 4.0 (mm) T: 0.3, 0.4, 0.5 (mm) H) 0.6, 0.8. 1.0, 1.2, 1.4
(Mm) An explosion-proof mechanism operation test was performed on each of these 10 unit cells. The test was performed by performing a 500 mA constant current charging test at room temperature. Table 1 shows the results.

[0012]

[Table 1]

In Table 1, ○ indicates that all of the 10 cells had the explosion-proof mechanism operated, and × indicates 1 of the 10 cells.
This shows the case where the explosion-proof mechanism was not activated even for an individual. Table 1
(T × r × T) of the thickness t of the thin portion, the distance r from the outer wall of the boss of the resin sealing body to the inner wall of the resin sealing body, and the bottom thickness T of the resin sealing body
FIG. 2 shows the relationship between the height and the height h from the bottom of the resin sealing body to the metal plate. In FIG. 2, the horizontal axis is (t × r
× T), and the vertical axis is h.

As shown in FIG. 2, the distribution of the operation and non-operation of the explosion-proof mechanism is such that the coefficient k of h = k × (r × T × t) is 3.7.
3 can be divided. That is, it is understood that the explosion-proof mechanism operated normally when h was set so that the coefficient k became 3.73 or more.

[0015]

As described above, in the alkaline dry battery of the present invention, the deactivation of the explosion-proof mechanism provided in the sealing body is prevented, and the safety is improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an AA alkaline battery LR6 according to an embodiment of the present invention.

FIG. 2 is a distribution diagram of explosion-proof mechanism operation in the embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Positive electrode mixture, 2 ... Negative electrode gel zinc, 3 ... Separator, 4
... Metal case, 5 ... Negative electrode terminal plate, 6 ... Metal plate, 7 ... Resin sealing body, 8 ... Resin thin part, 9 ... Negative electrode current collector, 10 ... Boss part of resin sealing body.

Claims (1)

[Claims] An opening of a metal case is sealed with a resin sealing body, wherein the resin sealing body is in contact with a negative electrode current collector, a bottom having a groove-shaped thin portion, and In an alkaline dry battery having a metal plate with a vent hole formed at a position from the boss to the inner wall of the resin seal above the bottom, the distance from the outer wall of the boss to the inner wall of the resin seal is r (mm). , The bottom thickness of the resin sealing body is T (m
m), when the thickness of the thin portion of the resin sealing body is t (mm) and the height from the bottom of the resin sealing body to the metal plate is h (mm),
An alkaline dry battery, wherein a coefficient k represented by the following equation: h = k × (r × T × t) is 3.73 or more.