JPS5998450A - Alkaline battery - Google Patents

Abstract

PURPOSE:To inhibit the run off of a gasket, enhance tightness of the gasket at the opening part of a metal can, and enable good liquid-leakproof property to be obtained, by forming a rising part on the peripheral part of the sealing plate of a negative electrode, and pushing this rising part to the gasket when bending the opening part of a metal can. CONSTITUTION:The peripheral part of a sealing plate 18 is bent in vertical direction in order to form a rising part 18a. In this case, the tip of the rising part 18a presents a flat shape. By bending inward the opening part of a metal can 11, the tip of the rising part 18a of the sealing plate 18 is strongly pushed to the projecting wall 155 for folding the edge of gasket 15, so that the run off of the gasket 15 is inhibited; and further the tightness between the sealing plate 18 and the gaskst 15, and the tightness between the opening part of the metal can 11 and the gasket 15 can be locally enhanced; and thereby good liquid leakproof property can be obtained.

Description

[Detailed description of the invention] This invention relates to an alkaline battery with an improved sealing structure.

Conventionally, as shown in FIG. 1, this type of alkaline battery uses an opening in a cylindrical anode metal can 1 in which the center is filled with a cathode material 3 and the surrounding area is filled with an anode mixture 2 via a separator 4. A protruding seat 1a is formed near the part, and this protruding seat 1
A synthetic resin insulating gasket 5 into which a current collector rod 6 derived from the cathode material 3 is inserted is supported by 1. A metal support 7 is inserted between the inner cylindrical part 51 and the outer cylindrical part 52 of the gasket 5, and the cathode sealing plate 8 is placed on the support 7. In this state, the metal can 1 is closed. There is a battery completed by bending the opening inward and pressing the peripheral edge of the cathode sealing plate 8 through the gasket 5 to tightly seal the space between the can 1 and the gasket 5.

According to this, the gasket 5 was considered to be locally compressed between the metal can 1 and the current collector rod 6 via the metal support 7.

However, when sealing the opening of the metal can 1, the metal can 1 is first compressed in the radial direction and then the opening end is bent. Further upwards, it cannot be held down and easily escapes toward the opening of the can 1. For this reason, it is not possible to actually compress the gasket 5 at a predetermined compression ratio even when the opening of the metal can 1 is bent, and as a result, the adhesion with the gasket at the opening of the metal can 1 is particularly poor. There was a drawback that the liquid leakage resistance deteriorated.

This invention was made in order to eliminate the above-mentioned drawbacks. A raised part is formed on the peripheral edge of the cathode sealing plate, and this raised part is pressed against the gasket when the metal can opening is bent, thereby preventing the gasket from escaping. An object of the present invention is to provide an alkaline battery that can improve the adhesion with a gasket at the opening of a metal can and provide good leakage resistance.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, reference numeral 11 denotes a cylindrical anode metal can, which is made by drawing a nickel-plated steel plate, stainless steel, or nickel-clad plate, and has an annular protruding seat along the inner peripheral surface near the opening. 11a.

The metal can 11 is filled with a power generation element. That is,
In this case, the center of the metal can 11 is filled with a cathode agent 12 made of gelled zinc, and a cathode active material such as manganese dioxide or silver oxide is placed around the cathode agent 12 through a separator 14 made of synthetic fiber. It is filled with an anode mixture 13 which is formed by adding and mixing a conductive agent such as graphite or acetylene black and a binder such as polystyrene and molding the mixture under pressure.

An insulating gasket 1 is placed on the protruding seat 11a of the opening of the metal can 11.
5 is set. This insulating gasket 15 is made of polyamide or polyethylene as shown in FIG.

It is integrally molded from thermoplastic synthetic resin such as polypropylene, and has an inner cylindrical portion 151 and an inner cylindrical portion 151.
It has an outer cylindrical portion 152 around the periphery thereof with a thin wall portion 153 interposed therebetween. In addition, the inner cylindrical portion 151 and the outer cylindrical portion 15
A step part 154 is formed on the upper part of the outer cylindrical part 1.
It has a projecting wall 155 for folding along the periphery of 52.

Then, such a gasket 15 is attached to the inner cylindrical portion 1.
A brass current collector rod 16 derived from the cathode material 12 is inserted into the hollow portion of the metal can 51, and the outer cylindrical portion 152 is placed on the protruding seat 11a of the metal can 11. Further, an annular metal support 17 is placed on the stepped portions 15-4 on the inner and outer cylindrical portions 151 and 152 of the gasket 15, and a cathode sealing plate 18 is placed thereon in contact with the current collector rod 16. ing. In this case, the sealing plate 18 has its peripheral edge bent in the vertical direction to form an upright portion 18a, as shown in FIG. In this case, the tip of the upright portion 18a is flat. Note that 19 in the 5 drawings is a hole for gas discharge.

In this state, fold the opening of the metal can 11 into the gasket 15.
The battery is completed by pressing the peripheral edge of the sealing plate 18 through the folding projecting wall 155.

According to such a configuration, as the opening of the metal can 11 is bent inward, the tip of the upright portion 18a of the sealing plate 18 is strongly pressed against the folding protrusion wall 155 of the gasket 15. Escape is prevented, and the adhesion between the sealing plate 18 and the gasket 15 and between the opening of the metal can 11 and the gasket 15 can be locally increased, thereby providing good leakage resistance. .

By the way, the L% type alkaline manganese dry battery [A] to which this invention is applied and the conventional same type dry battery (A) explained in Fig.
B) When 100 pieces of each were stored for a predetermined period of time in an atmosphere of 60° C. and relative humidity of 90q6, the rate of leakage was investigated, and the results shown in the table below were obtained.

From the above results, it has been found that the alkaline battery obtained according to the present invention has significantly improved leakage resistance compared to conventional batteries.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be implemented with appropriate modifications without changing the gist.

For example, in the above embodiment, the upright portion 18a of the cathode sealing plate 18
Although the tip is flat, it may also be rounded and convex. In this way, the pressing points on the gasket 15 can be concentrated, so that the adhesion of the gasket 15 can be further improved. Further, the tip of the upright portion 18a may be formed into a sharp convex shape. This allows the upright portion 18a to bite into the gasket 15 by pressing against it, thereby further increasing the adhesion between the upright portion 18a and the gasket 15.

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram for explaining a conventional alkaline battery, Figure 2 is a schematic configuration diagram showing an embodiment of the present invention, and Figure 3 is a cross section showing an insulating gasket used in the embodiment. 4 are sectional views showing a cathode sealing plate used in the same embodiment. 1.11...Metal can 1a, lla...Protruding seat 2.13...Anode mixture 3,12...Cathode agent 4.14...Seharl/-15,15...Insulating gasket 51, 151 ... Inner cylindrical part 52.15
2...Outer cylindrical part 153...Thin wall part 1
54... Step portion 155... Projection wall 6, 16
... Current collector rod 7.17 ... Metal support 8,18
・-・Cathode sealing plate 18a... Standing part 19・
...Kobe's agent, patent attorney Yuki Komiya - Bachelor of Arts. Figure 30 Figure 4

Claims (4)

[Claims] (1) A cylindrical metal can filled with a power generation element, and an insulating gasket that is provided at the opening of the metal can, supports a current collector rod led out from the power generation element, and has a projecting wall for folding along the periphery. and a sealing plate that is provided on the gasket in contact with the current collector rod and has a raised portion on its peripheral edge, and when the opening of the metal can is bent inward, the raised portion of the sealing plate is An alkaline battery characterized by being pressed against a folding wall of a gasket. (2) The alkaline battery according to claim 1, wherein the sealing plate has a flat tip end thereof. (3) The alkaline battery according to claim 1, wherein the sealing plate has a convex end with a rounded end. (4) The alkaline battery according to claim 1, wherein the sealing plate has a raised portion with a pointed convex tip.