JPH10233194A - Cylindrical alkaline battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the safety of a cylindrical alkaline battery by surely inserting a current collector comprising a negative terminal, a current collecting rod, a metallic plate, and a gasket, so that it is not moved, and securing the caulking strength of its opening. SOLUTION: A cylindrical alkaline battery has a generating element packed in a positive electrode can 1, a bead 11 is provided at the opening of the positive electrode can to support a current collector comprising a negative terminal, a current collecting rod, a metallic plate, and a gasket 7, and the opening of the positive electrode can is caulked to seal the battery. Since the side face of the gasket 7 is made to coincide in shape with the inner surface of the opening of the positive electrode can including the bead, the current collector is inserted without moving or floating even if the size of the gasket is varied as the result of absorption of water, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cylindrical alkaline battery having an improved gasket.

[0002]

2. Description of the Related Art The structure of a conventional cylindrical alkaline battery is shown in FIG. As shown in FIG. 3, the cylindrical alkaline battery has a positive electrode mixture 2 composed mainly of manganese dioxide inserted along the inside of a positive electrode can 1, and a bottomed cylindrical mixture inside the positive electrode mixture. The separator 3 is inserted, the alkaline electrolyte is absorbed therein, and the gelled negative electrode zinc 4 obtained by mixing the zinc powder and the gelled electrolyte is injected, and the bead 1 is placed between the upper part of the positive electrode can and the upper surface of the mixture.
1, a current collector comprising a negative electrode terminal 5, a current collecting rod 6, a gasket 8, and a metal plate 9 was inserted from the opening of the positive electrode can and supported by a bead 11, and the opening of the positive electrode can was caulked inward and sealed. It has a configuration.

In an alkaline battery using zinc as a negative electrode active material, gas may be generated inside the battery due to charging due to misuse or a corrosion reaction of zinc, and if the internal pressure increases, the battery may explode. When the internal pressure becomes high, a gas vent safety valve provided in the gasket of the current collector prevents rupture. The safety valve of this gasket has a part where the strength of the gasket is reduced by thinning a part of the gasket.When the internal pressure increases, the safety valve breaks, and the internal gas is discharged to the outside and the battery is discharged. To prevent the rupture.

[0004]

Since the gasket is made of a nylon resin, the water absorption changes depending on humidity and temperature, and the dimensions are apt to change. If the dimensions change, the current collector cannot be inserted into the specified position, and the diameter of the positive electrode can opening after caulking will differ. As a result, when the opening diameter becomes larger than the specified value, the swaging strength of the current collector decreases. If the current collector caulking strength is lower than the strength of the gasket gas release safety valve, there is a risk of explosion when the pressure inside the battery increases. For this reason, in the related art, all batteries caulked without inserting the gasket into a prescribed position have been discarded as defective products.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems. When a current collector is inserted in a manufacturing process of a cylindrical alkaline battery, the current collector is prevented from being lifted or displaced, and the upper portion of a positive electrode can is caulked. An object of the present invention is to reliably perform the crimping of the current collector and thereby secure the caulking strength of the current collector, thereby improving the safety and reliability of the product.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is an improvement in the shape of a gasket for a cylindrical alkaline battery. A bead is provided in the opening to create a negative electrode terminal, current collector,
In a cylindrical alkaline battery supporting a current collector made of a metal plate and a gasket and caulking and sealing the positive electrode can opening, the gasket has a side surface shape that matches the shape of the inner surface of the positive electrode can opening including the bead. It is characterized by being.

In the present invention, since the side shape of the gasket, including the bead, conforms to the shape of the inner surface of the can, the current collector including the gasket is inserted even when the size of the gasket changes due to the influence of temperature and humidity. When this is done, it can be securely inserted into the can without causing a displacement. Therefore, the opening diameter after caulking is stable, and secure caulking strength can be secured.

[0008]

Embodiments of the present invention will be described below. (Embodiment 1) FIG. 1 is a sectional view of a cylindrical alkaline battery showing an embodiment of the present invention. 1, the same components as those in FIG. 3 are denoted by the same reference numerals. This cylindrical alkaline battery
A cylindrical positive electrode mixture 2 mainly composed of manganese dioxide is inserted along the inside of the positive electrode can 1, a bottomed cylindrical separator 3 is inserted inside the positive electrode mixture, and the alkaline electrolyte is absorbed therein. Then, a gelled negative electrode zinc 4 obtained by mixing zinc powder and a gelled electrolyte is injected. A bead 11 is provided between the upper portion of the positive electrode can and the upper surface of the mixture, and 1 kg of a current collector including the negative electrode terminal 5, the current collecting rod 6, the gasket 7, and the metal plate 9 is opened from the opening of the positive electrode can.
Inserted vertically with force f.

In the above description, the gasket 7 is made of a non-reinforced nylon resin, and has a side surface shape along the inner surface of the positive electrode can including a bead as shown in FIG. FIG. 4 shows the shape of a conventional gasket. When the gasket is inserted into the positive electrode can, it does not have a shape along the bead as shown in FIG.

With respect to the battery of Example 1 (LR6 size), a displacement test of the current collector was performed. The gasket had a water absorption of 4%. Further, as Comparative Example 1, a gasket having a shape not conforming to the shape of the bead as shown in FIG. 4 was used, and otherwise the same as Example 1 was used.
The same test was performed. As a result of these tests, the number of deviations of the current collector is shown in Table 1.

[0011]

[Table 1]

Example 2 The upper part of the positive electrode can of the LR6 battery of Example 1 was caulked inward and hermetically sealed.

As Comparative Example 2, the upper part of the positive electrode can of the LR6 battery of Comparative Example 1 was caulked inward and sealed. These batteries were subjected to a 600 mA constant current charging test. Table 2 shows the case where the safety valve was activated and the liquid was leaked, and the case where the safety valve did not operate and burst.

[0014]

[Table 2]

As shown in Table 2, in the second embodiment, when the current collector is inserted, there is no deviation, the caulking can be surely performed, and the specified caulking strength can be secured. In the comparative example, there were three displacements of the current collector, and one of the three ruptured in the charging test.
This is because the caulking strength of the positive electrode can was weakened due to the displacement of the current collector, and the caulking strength was weaker than the safety valve strength, so when gas was generated inside the battery due to charging and the internal pressure increased, it led to rupture. It is a thing. This has confirmed that the present invention improves safety and reliability.

[0016]

As described above, according to the present invention,
Since the insertion of the current collector is ensured and no lifting or displacement occurs,
The specified caulking strength can be secured. Therefore, even if internal gas is generated due to misuse and the internal pressure of the battery is increased, the safety valve operates to prevent the battery from being ruptured, thereby improving safety and reliability.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an LR6 size cylindrical alkaline battery according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view of the gasket in FIG.

FIG. 3 is a cross-sectional view of a conventional LR6 size cylindrical alkaline battery.

FIG. 4 is a cross-sectional view of the gasket in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Positive electrode can, 2 ... Positive electrode mixture, 3 ... Bottomed cylindrical separator, 4 ... Gelled negative electrode zinc, 5 ... Negative electrode terminal, 6 ... Collector rod,
7, 8 ... gasket, 9 ... metal plate, 10 ... exterior label,
11: positive electrode can bead portion, 12: positive electrode can caulking portion.

Claims (2)

[Claims] 1. A positive electrode can is filled with a power generating element, a bead is provided in an opening of the positive electrode can to support a current collector comprising a negative electrode terminal, a current collecting rod, a metal plate, and a gasket, and the opening of the positive electrode can is caulked and sealed. In the cylindrical alkaline battery described above, the gasket has a side surface shape that matches the shape of the inner surface of the opening of the positive electrode can including the bead. 2. The cylindrical alkaline battery according to claim 1, wherein the gasket is a non-reinforced nylon resin.