JPH04296444A - Sealing port for cylindrical closed type battery - Google Patents

Abstract

PURPOSE:To reduce a thickness of a battery can for an increase in inner volume so as to increase the volume and reduce a weight by increasing the thickness of side surfaces of the battery can, which has conventionally had uniform thickness, more than portions other than a caulked portion. CONSTITUTION:A thickness of a caulked portion A of a battery can 11 is, e.g. 0.3mm or so, and a thickness of a side wall portion B is, e.g. 0.2mm or so. The caulked portion A is caulked in a predetermined thickness while controlling a stroke by the use of a drawing die 4 or a pushing punch, or the thickness of the portions other than the portion A is reduced by spinning. If it is not preferable that the thickness of the portion A is larger than the other portions, that is, its outer diameter is 0.2mm or so, the outer diameter is reduced to the same diameter as that of the other portions.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed cylindrical battery, and more particularly to the structure of a sealed cylindrical nickel-cadmium storage battery.

0002

[Prior Art] Conventionally, sealed cylindrical nickel-cadmium storage batteries are sealed by making grooves near the mouth of a deep-drawn cylindrical can 1 by a press, which serves as the exterior, using a rotating roll, applying a sealant, and then sealing the can with a seal packing 2. The top lid 3 is inserted through the can, and the can opening is caulked to seal the can. Here, the wall thickness of the deep-drawn cylindrical can 1 serving as the exterior is the same for both the can bottom U and the can side surface S (about 0.3 mm). In particular, the sides of the can have a uniform wall thickness.

0003

[Problems to be Solved by the Invention] In this type of storage battery, the wall thickness of the cylindrical can 1 tends to become thinner in order to increase the capacity and reduce the weight. As a result, the wall thickness of the caulked portion becomes thinner, resulting in a decrease in sealing force and proof strength due to an increase in internal pressure, and there is a concern that the reliability of electrolyte leakage resistance, which is an important issue, will decrease.

0004

[Means for Solving the Problems] The wall thickness of the side surface of a cylindrical can, which was conventionally uniform, is changed so that the portion used for caulking is thicker than other portions.

[0005]

[Function] By making the wall thickness of the caulking part of the battery can thicker than other parts of the side of the can, the capacity can be increased by thinning the can wall without reducing the leakage resistance reliability of the electrolyte. Lighter weight can be achieved.

[0006]

[Example] An example of the present invention will be described. The battery can structure is such that the caulked portion A of the battery can 11 has a wall thickness of, for example, about 0.3 mm, and the side wall portion B other than the caulked portion A has a wall thickness of, for example, about 0.2 mm.

The battery can 11 according to the present invention is manufactured by a manufacturing method in which the stroke is controlled by ironing with the ironing die 4 and the thickness of the caulked portion A is left (FIG. 3). 5
is a push-in bonchi. FIG. 4 shows a method of reducing the wall thickness in areas other than the caulked portion A by spinning. 6 is a spinning roll, and 7 is a rotating core. However, when the battery can 11 manufactured by these methods is used for caulking, the outer diameter of the caulked portion A increases by about 0.2 mm due to the increased wall thickness. Therefore, the diameter of the caulked portion A is reduced to the same outer diameter as the battery can 11 by a method using a diameter reducing die 41 shown in FIG. 5 or a method using a spinning process shown in FIG. 8 is a receiving mold, 9 is a rotating holder, and 10 is a spinning top.

[0008]

[Effects of the Invention] As described above, according to the present invention, the wall thickness of the caulked part of the battery can is the same as before, so the reliability of electrolyte leakage resistance is not reduced, and the thickness of the other parts on the side of the can is improved. By making the wall thinner, the inner volume can be increased, resulting in higher capacity and lighter weight, which has great industrial value.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part showing the sealing part of a sealed battery of the present invention using a battery can in which the thickness of the caulked part of the battery can is thicker than the wall thickness of the side surface of the can other than the caulked part. be.

FIG. 2 is a schematic explanatory diagram of the battery can shown in FIG. 1.

FIG. 3 is a schematic diagram of a processing method according to the present invention, in which the thickness of the caulked portion is kept thick by reducing the thickness of the caulked portion by ironing with an ironing die.

FIG. 4 is a schematic diagram of a processing method according to the present invention in which the thickness of the caulked portion is kept thick by reducing the thickness of the caulked portion by spinning using a spinning roll.

FIG. 5 is a schematic diagram of a diameter reduction processing method using a diameter reduction die according to the present invention.

FIG. 6 is a schematic view of diameter reduction processing by spinning piece processing in the present invention.

FIG. 7 is a sectional view of a main part of a sealed battery using a conventional battery can in which the wall thickness of the caulked portion and the side surface of the can other than the caulked portion is uniform.

FIG. 8 is a schematic diagram of the battery can shown in FIG. 7.

[Explanation of symbols]

Claims (1)

[Claims] 1. A sealed portion of a cylindrical sealed battery characterized by using a battery can in which the side wall portion of the battery can is formed to be thinner than the thickness of the caulked portion.