JPS5812708B2 - Manufacturing method for sealed alkaline batteries - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an alkaline battery having a sealed structure.

In general, alkaline batteries are usually of a sealed type for convenience of use.

Incidentally, this alkaline battery is normally sealed by interposing packing in an annular gap around the battery lid.

Specifically, a packing is placed in the annular gap, and then a metal member surrounding the packing, for example, the upper end of a metal container of a battery, is caulked inward to compress the packing. Since it will be present in the gap in a constantly compressed state, it should be able to exhibit a high degree of sealing effect.

However, the alkaline electrolyte in alkaline batteries has a particularly strong leaching property, and for this reason, if alkaline batteries are used for a long period of time, even if the alkaline batteries have a sealed structure as described above, the battery life will be shortened. The electrolyte may seep out from around the packing before it breaks.

Incidentally, the reason why the sealing effect of the packing is not always sufficient as described above is often due to insufficient compression of the crimped portion against the packing.

This under-compression of packing occurs as follows.

That is, when the caulked portion is formed using a curl mold or the like, the metal container portion of the battery is also pressed with a considerably large molding pressure.

Therefore, the metal container part also elastically deforms, but when the curling mold is removed after the caulking part is formed, it returns to its elastic state at the moment.

As a result, the caulked portion moves back and the packing becomes loosely tightened.

This tendency is particularly noticeable in thin batteries.

This is because the thinner the battery is, the more easily the metal container supporting the caulked end becomes flexible.

Therefore, in order to obtain a sufficient sealing effect by packing, especially with a thin battery, it is necessary to use a metal container with low elasticity or a packing with spring elasticity greater than that of the metal container. In reality, seeking something like this is extremely difficult.

Therefore, an object of the present invention is to prevent the tightness of the packing from being deteriorated due to the spring elasticity of the metal container, even in a thin battery; It is an object of the present invention to provide a method for producing a sealed alkaline battery which can have a favorable effect on the loading condition and thereby maintain a high level of leakage resistance over a long period of time.

That is, the method for manufacturing an alkaline battery according to the present invention is as follows:
When a sealed alkaline battery is obtained by sealing the annular gap around the lid of an alkaline battery with an annular packing, a bent part that annularly surrounds a portion extending from the top to the outside of the packing and this bent part are formed. A metal ring with an integral structure consisting of a flange part continuous to the outer end of the metal ring is used, and while compressing the packing with the bent part of this metal ring, the flange part is formed in advance on the side of the battery container. By sandwiching it between welding electrodes and electrically welding both flanges together, a good packing tightness can be obtained.
This aims to provide a sealed alkaline battery that maintains a high level of leakage resistance over a long period of time.

Embodiments of the present invention will be described in detail below with reference to the drawings.

First of all, the sealed alkaline battery manufactured according to the present invention is a particularly thin battery, as shown in the figure as an example thereof, and includes a metal lid part 1 which also serves as a cathode terminal, an annular packing 2, a metal ring 3, and an anode. The metal container portion 4, which also serves as a terminal, constitutes a battery container with a sealed structure, and an anode 7, a separator 8, and a cathode 9 are accommodated in a stacked state inside this container.

Here, the lid part 1 has a disk-like planar shape,
Its outer peripheral edge is bent to one side, and a slight fold is formed on the outer peripheral end to obtain spring elasticity in the vertical direction.

Further, the material used is a cladding material made of copper bonded to stainless steel, and the copper side surface becomes the inner surface and comes into contact with the cathode 9.

The annular packing 2 is made of nylon, and is integrally molded in advance by injection molding onto a folded part formed at the outer peripheral end of the lid part 1.

As shown in the figure, the metal ring 3 has a curved portion 3 that annularly surrounds a portion extending from above to the outside of the packing 2.
A and a flange portion 3b continuous to the outer end of the bent portion 3a are integrally formed, and the material thereof is preferably a steel material with high spring elasticity.

The metal container portion 4 has a flange portion 4b formed at its outer peripheral end, and this flange portion 4b overlaps the flange portion 3b of the metal ring 3. The vicinity of the bent portion 3a contacts the upper side of the packing 2, and the flange portion 3b
is positioned so as to overlap above the flange portion 4b of the metal container portion 4, and in this state is placed between a pair of welding electrodes 5, 60 arranged vertically.

Then, the two flanges 3b and 4b are sandwiched together with the upper electrode 5 and the lower electrode 6, and the weight is 300 to 400 kg.
Both flanges 3b and 4b are electrically welded together while compressing the packing 2 in the vertical direction using electrode pressure.

As a result, the packing 2 is compressed by the pressure between the electrodes 5 and 6, but this compressed state is
By electrically welding b and 4b to each other, electrodes 5 and 6
It remains intact even after being removed from the

At this time, an elastic restoring force acts on the bent portion 3a due to the release of the welding pressure, but since this elastic restoring force acts in a direction that constantly tightens the packing 2, the packing 2 is Not only will it not loosen after being taken out of the bag, but it will always maintain good tightness even if the packing expands or contracts due to long-term use or changes in environmental temperature. .

Therefore, it is possible to obtain a sealed alkaline battery with excellent leakage resistance that can be safely used in devices where the battery will not be replaced for more than 5 to 6 years.

The embodiments have been described above, but as is clear from the above description, the method for manufacturing a sealed alkaline battery according to the present invention is to seal the annular gap around the lid of the alkaline battery with an annular packing. In order to obtain a sealed alkaline battery, a metal ring with an integral structure is used, which consists of a bent part that annularly surrounds the part extending from the top to the outside of the packing, and a flange part that continues to the outer end of this bent part. death,
While compressing the packing with the bent part of this metal ring, the flange part is sandwiched between welding electrodes together with the flange part previously formed on the battery container side, and both flange parts are welded to each other. Unlike in the past, the spring elasticity of the metal container part no longer deteriorates the tightening condition of the packing, but rather the spring elasticity of the metal container section and the metal ring has a positive effect on the tightening condition of the packing. This allows you to
In particular, it is possible to obtain a sealed alkaline battery that ensures a high degree of leakage resistance over a long period of time even in a thin battery.

[Brief explanation of the drawing]

The figure is a sectional view for explaining one embodiment of the method according to the present invention. 1...Lid, 2...Packing, 3.
...Metal lagoon, 3a...Bent part, 3b
...Flange part, 4...Metal container part,
4b... Flange portion, 5, 6... Welding electrode, 7... Anode, 8... Separator, 9... Cathode.

Claims (1)

[Claims] 1. When obtaining a sealed alkaline battery by sealing the annular gap around the lid of an alkaline battery with an annular packing, a folded part that annularly surrounds the part extending from the top to the outside of the packing and this fold is formed. A flange part in which the flange part is formed in advance on the battery container side while compressing the packing with the bent part of the metal ring. and a method for manufacturing a sealed alkaline battery, characterized in that both flanges are welded to each other by being sandwiched between welding electrodes.