JP3055396B2 - Manufacturing method of sealed battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed battery in which a power generating element such as a button battery, a coin battery, and a cylindrical battery is liquid-tightly sealed with a sealing plate, a battery case, and an insulating gasket. It concerns the manufacturing method.

[0002]

2. Description of the Related Art FIG. 2 is a partial sectional view of a coin-type lithium battery.

In FIG. 2, reference numeral 21 denotes a battery case made of metal and also serving as a positive electrode terminal, and reference numeral 22 denotes a metal positive ring disposed on the inner bottom surface of the battery case 21. 23 is a positive electrode ring 22
Manganese dioxide, graphite,
It is obtained by press-molding a mixed powder of a binder and the like. Reference numeral 24 denotes a separator inserted in a cup shape on the positive electrode mixture 23 and impregnated with an organic electrolyte. Reference numeral 25 denotes negative electrode metallic lithium disposed on the separator 24. Reference numeral 26 denotes an insulating gasket made of a synthetic resin having an L-shaped cross section, and reference numeral 27 denotes a metal sealing plate which also serves as an inverted dish-shaped negative electrode terminal that closes an opening of the battery case 21 with the insulating gasket 26 interposed therebetween.

[0004] This coin-shaped lithium battery is shown in FIG.
After the sealing plate is installed in the opening of the battery case, the battery case 21 is placed on the jig 28, and then the jig 28 is raised to make the inside of the mold 29 curved into a bell shape.
The upper portion of the side surface of the battery case 21 was pressed against the portion 30 to seal the battery case 21 to form a battery 31 as shown in FIG.

[0005]

However, in this sealing method, since the pressure is applied by bringing the upper end of the side of the battery case into contact with the mold 29, as shown in FIG. Burrs were likely to occur on the part and the bottom edge. Then, the sealing state between the battery case and the sealing plate was deteriorated, and the liquid leakage resistance of the battery was reduced.

The present invention solves such a problem. When the upper side of the battery case is bent inward with a mold, sliding friction is generated by causing the side of the battery case to follow the mold, This force prevents the battery case from receiving a large impact.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a method of manufacturing a sealed battery according to the present invention is characterized in that the inside is curved like a bell with respect to the center axis of a bottomed cylindrical battery case and a sealing plate. The center axis of the mold is tilted, the upper side of the battery case is pressed relatively to the inside of the mold while rotating the center axis of the mold, and the upper side of the battery case is bent inward to seal the battery. is there.

[0008]

In the manufacturing method of the present invention, the center axis of the mold whose inside is curved like a bell is inclined with respect to the center axis of the cylindrical battery case and the sealing plate, and the mold is rotated while rotating the mold. Since the inside of the mold is relatively pressed against the upper side, the upper end of the side of the case is bent inward and crimped in order according to the rotation of the mold and the pressing speed of the battery case. And the sealing plate can be sealed.

In this method, the friction between the mold and the upper end of the battery case is reduced by sliding, so that the sliding component can be reduced to realize a sealing mainly composed of rolling components, and a large pressure is applied to the battery case. This prevents the occurrence of burrs and prevents the battery from being sealed, thereby improving the liquid leakage resistance of the battery.

[0010]

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

A method for manufacturing the battery of the present invention will be described with reference to FIG. 1A, reference numeral 1 denotes a center axis of the battery case 21 and the sealing plate 27, and reference numeral 2 denotes a mold 29 whose inside is curved like a bell.
The central axis 2 of the mold is inclined by 3 ° with respect to the central axis 1 of the battery case and the sealing plate.

Then, as shown in FIG. 1 (B), the jig 28 is raised while rotating the center axis of the mold 29 at an appropriate number of rotations about the center axis of the battery case 21 and the sealing plate 27. As a result, the upper side of the battery case 21 was pressed against the inside of the mold 29. With this, the upper side of the battery case is bent inward to seal the battery case and the sealing plate,
This was designated as Battery A of the present invention. Here, the diameter of the battery is 2
0 mm and a height of 3.2 mm.

Next, 10,000 batteries A of the present invention and 10000 conventional batteries B as shown in FIG. 3 were produced, and at this time, the occurrence of burrs at the upper end of the case opening and the periphery of the bottom of the case was observed.

The results are shown in (Table 1).

[0015]

[Table 1]

Further, a heat cycle test was conducted using 100 batteries A of the present invention and 100 batteries of the conventional battery B, and the state of liquid leakage at this time was examined.

The heat cycle test was conducted at 10 ° C. for 1 hour,
Temperature rise from 0 ° C to 60 ° C for 1 hour, 60 ° C for 1 hour, 6
The battery was stored under this atmosphere with the temperature being reduced from 0 ° C. to 10 ° C. for one hour as one cycle, and this was performed for 30 days.

The results are shown in (Table 2).

[0019]

[Table 2]

As can be seen from (Table 1) and (Table 2), the battery of the present invention can prevent burrs from being generated in the battery case when the battery is sealed, and can improve the sealed state of the battery. Was able to improve the leakage resistance.

The position of the intersection of the central axis of the battery case with the sealing plate and the central axis of the mold is preferably within a range of 30 mm upward from the position where the sealing plate and the inside of the mold are in contact. Although the angle of the center axis of the mold with respect to the center axis of the battery case and the sealing plate is set to 3 °, the angle may be 30 ° or less.

[0022]

According to the manufacturing method of the present invention, the center axis of the mold whose inside is curved like a bell is inclined with respect to the center axis of the cylindrical battery case and the sealing plate, and the battery is rotated while rotating the mold. Since the inside of the mold is relatively pressed against the upper part of the side of the case, the upper end of the side of the case is bent inward sequentially according to the rotation of the mold and the pressing speed of the battery case. The battery case and the sealing plate can be sealed.

According to this method, the friction between the mold and the upper end of the battery case is reduced by sliding, so that the sliding component can be reduced to realize a sealing mainly composed of a rolling component, and a large pressure is applied to the battery case. This prevents the occurrence of burrs and prevents the battery from being sealed, thereby improving the liquid leakage resistance of the battery.

[Brief description of the drawings]

FIG. 1A is a diagram showing a state before sealing of a sealed battery of the present invention; FIG. 1B is a diagram showing a state after sealing;

FIG. 2 is a partial cross-sectional view of a coin-type battery.

3A is a view showing a state before sealing of a conventional sealed battery; FIG. 3B is a view showing a state after sealing; and FIG. 3C is a view showing the occurrence of burrs in a conventional sealed battery.

[Explanation of symbols]

 Reference Signs List 1 central axis of battery case and sealing plate 2 central axis of mold 21 battery case 22 positive electrode ring 23 positive electrode mixture 24 separator 25 metallic lithium 26 insulating gasket 27 sealing plate 28 jig 29 mold 30 R part 31 battery

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazusuke Nishimura 1006 Kazuma Kazuma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-2-207449 (JP, A) JP-A-61 -259451 (JP, A) JP-A-61-29062 (JP, A) JP-A-5-266866 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01M 2/02- 2/08 B21D 39/00

Claims (2)

(57) [Claims] 1. A sealing plate, which also functions as a negative electrode terminal, is installed in an opening of a cylindrical battery case having a bottom, which also functions as a positive electrode terminal, via an insulating gasket. A method of manufacturing a sealed battery in which a battery case and a sealing plate are sealed by being bent inward by a mold,
The center axis of the bell portion of the mold is inclined with respect to the center axis of the battery case and the sealing plate, and the upper side of the battery case is pressed relatively to the inside of the mold while rotating the center axis of the mold. A sealed battery manufacturing method in which the upper side of the battery case is bent inward to seal the battery. 2. The method for manufacturing a sealed battery according to claim 1, wherein the center axis of the mold is inclined by 30 ° or less with respect to the center axes of the battery case and the sealing plate.