JPS63245851A - Process for manufacture of angular enclosed battery - Google Patents

Abstract

PURPOSE:To improve sealability by making curvature inward at upper side of at least two faces of a sealed cover plate edge and making curvature inward at upper side of caulking part of a corresponding case opening, so that swelling the case opening outward is prevented. CONSTITUTION:After placing inside an L-type gasket 2, which has been injection-molded with a resin, a sealed cover plate 3 is inserted into opening of a metal case 1. Two facing fringe surfaces of the sealed cover plate 3 are formed with inward curvature at the upper side. Then, using a drawing die 4, which has a leading taper D1 with a concave lens-like opening at the upper side, an opening of the metal case 1 is curved by drawing to complete an angular enclosed battery. By such a drawing process, an inward curve, in the top view, of linear part at the opening of metal case 1 is formed, resulting in an excellent battery with good sealability and no possibility of hazardous ellipsoidal expansion of the opening in the metal case 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a prismatic sealed battery in which the shape of the sealing member is improved.

[Conventional technology]

Conventionally, prismatic sealed batteries, especially small portable prismatic sealed batteries, are made by press-fitting an insulating gasket with a cover plate inside the opening of a bottomed prismatic cylindrical metal case containing a power generation element, and then inserting the open end of the case inside. It was curved towards the side and sealed.

[Problem that the invention seeks to solve]

In the case of such a manufacturing method, since the sealing force in the lateral direction of the sealing portion is the repulsion elastic force of the gasket, there is a problem that sufficient sealing performance cannot be obtained.

Therefore, in order to improve the sealing performance, a method is used in which the opening of the case is expanded outward in advance, the opening end is curved inward when caulking, and the previously expanded opening is narrowed down to the body.

However, in this method, in order to improve sealing performance, a gasket made of relatively hard synthetic resin such as nylon or polypropylene is used and is compressed by about 20 to 60%. There was a problem that backing occurred and the caulked portion at the opening end of the metal case tended to expand outward, resulting in a decrease in sealing performance.

This invention was made to solve these problems, and it provides a prismatic sealed battery that maintains high sealing performance without the fastening part loosening even if there is springback due to the rigidity of the gasket. The purpose is to provide a manufacturing method for.

[Means and effects for solving the problem] In order to achieve the above object, the present invention inserts a sealing cover plate through an insulating gasket into the opening of a bottomed rectangular cylindrical metal case in which a power generating element is housed. In a rectangular sealed battery which is sealed by bending the open end of the case inward and caulking after the opening of the case, the sealing cover plate is formed so that at least two of its edges have an upper surface shape that is curved inward. At the same time, the corresponding caulking portion at the opening end of the case is caulked so as to have an inwardly curved upper surface shape.

By adopting this configuration, it is possible to prevent the case opening from bulging outward due to the springback of the insulating gasket compressed between the sealing lid plate and the metal case after caulking, improving sealing performance. do.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

1 to 5 show the manufacturing process of this embodiment. In FIGS. 1(a) and 1(b), reference numeral 1 denotes a metal case in which a flat metal plate is formed into a rectangular tube shape with a bottom by drawing or welding, and the opening is expanded outward. Reference numeral 2 denotes an insulating gasket having an angular cross section obtained by injection molding of synthetic resin, and the upper surface of the rising portion of the peripheral edge is rectangular or concave lens shaped.

After placing the sealing cover plate 3 in this gasket 2, it is inserted into the opening of the metal case 1.

As shown in FIG. 2, the sealing lid plate 3 used has an upper surface shaped like a concave lens. That is, the two opposing edges of the sealing lid plate 3 have an upper surface shape that is curved inward.

Next, as shown in FIGS. 3 and 4, the opening of the metal case 1 is narrowed and curved using a drawing die 4 whose upper surface has a concave lens shape and a drawing taper D1.
A square sealed battery as shown in FIG. 5 is completed.

In this way, by squeezing, the linear part of the opening of the metal case 1 is curved inward when viewed from above, so there is no danger of the opening of the metal case 1 expanding outward into an oval shape. It is possible to obtain a battery with excellent sealing properties.

Note that the present invention is not limited to the above-mentioned embodiments, and can be implemented with various modifications without changing the gist.

In the above embodiment, the upper surfaces of the two opposing surfaces of the edge of the sealing lid plate and the opening of the battery container are curved inwardly, but the shape is not limited to this, and the other two or more surfaces may be curved inwardly. It is also possible to have a configuration like this.

〔Effect of the invention〕

According to this invention, the top surface of at least two end faces of the sealing board is curved inward, and the corresponding top surface of the caulking portion of the case opening is curved inward, so that the lid plate and the metal case are separated after caulking. Since it is possible to prevent the case opening from expanding outward due to springback of the insulating gasket compressed between the two, the sealing performance can be improved.

[Brief explanation of drawings]

FIG. 1(a) Φ) shows the structure of the sealing part before caulking in an embodiment of the present invention, FIG. 1(a) is a perspective view, Φ) is a longitudinal sectional view, and FIG. Fig. 3 is a plan view of the drawing die, Fig. 4 is a longitudinal cross-sectional view of the drawing die, Fig. 5(a)
A) shows the configuration of the sealing part of the same example after drawing.
) is a plan view, and Φ) is a longitudinal sectional view. 1... Metal case 2... Insulating gasket 3
...Sealing lid plate 4...Drawing die Fig. 1 Fig. 3 Fig. 2 Fig. 5

Claims (1)

[Claims] In the rectangular sealed battery in which a sealing cover plate is inserted into the opening of a bottomed rectangular cylindrical metal case containing a power generation element through an insulating gasket, the opening end of the case is bent inward and caulked to seal the opening. Place the sealing lid plate on at least 2 of its edges.
Manufacture of a prismatic sealed battery, characterized in that the surface is formed to have an inwardly curved upper surface shape, and a corresponding caulked portion at the opening end of the case is caulked so as to have an inwardly curved upper surface shape. Method.