JP2632492B2 - Manufacturing method of battery sealing plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a battery sealing plate.

[0002]

2. Description of the Related Art As is well known, a coin-type battery such as a lithium battery is configured as shown in FIG.
In FIG. 1, reference numeral 1 denotes a case, in which an anode active material 2, a separator 3, and a cathode active material 4 are sequentially stacked and installed, and an opening of the case 1 is sealed by a sealing plate 5.

[0003] The sealing plate 5 has a rib 6 for reinforcement formed in a stepped shape on a peripheral shoulder thereof, and a peripheral edge 7 following the rib 6 is formed as a vertical side wall 8. The lower end of the side wall portion 8 is bent at a right angle so as to contact the outer periphery of the side wall portion 8 to form a bent portion 9. Therefore, the peripheral edge portion 7 has a double structure by the side wall portion 8 and the bent portion 9.

[0006] The peripheral portion 7 is inserted into an annular packing 10 arranged on the inner periphery of the case 1. Then, by crimping the upper end of the side wall 1A of the case 1 inward, the packing 10 is more firmly sandwiched between the peripheral portion 7 and the peripheral portion 7 is fixed to the case 1 via the packing 10. The opening surface of the case 1 is sealed with a sealing plate 5.

[0005] The electrolyte in the case 1 cannot be leaked by the packing 10 sandwiched between the cases.
In order to ensure this leakage, it is necessary to finish the height of the peripheral portion 7, particularly the height of the bent portion 9, with high precision. If this is lower than the packing 10, the packing 10 cannot be sufficiently pressurized when caulking the side wall 1A, which may cause a liquid leakage.

Conventionally, the sealing plate 5 has been manufactured as follows. FIG. 5 shows the manufacturing process. First, a circular blank 11 is cut into a required size from a plate material (step a), and a main body portion 12 serving as a sealing plate main body is cut.
Is bent to form the side wall portion 8 and the flange 13 is drawn at the lower end of the side wall portion 8 (step b).
Next, the ribs 6 are formed in steps from the upper end of the side wall portion 8 to the shoulder portion of the main body portion 12 (step c).

Next, the flange 13 is cut to a predetermined length and trimmed (step d), and then the outer end of the remaining flange 13 is curled and preliminarily bent upward (step e). The bent end portion is formed into a bent portion 9 by forming the end portion upright (step f). Thereafter, the height is corrected (step g), and the fabrication is completed.

According to such a conventional method, as shown in the step (e), the rib 6 is formed in the step (c) and the side wall portion 8 is formed vertically before the curling process is performed. . Thereafter, the curling process for preliminary bending the bent portion 9 is performed. In this curling process, it is required that the bent portion 9 be bent as perpendicularly as possible.

FIG. 6 is a sectional view showing a conventional curling process, wherein 14 is a lower mold and 15 is an upper mold. In order to perform the curling process so that the bent portion 9 is bent at a right angle as much as possible, the angle α of the tip portion 16 that is pressed and inserted between the side wall portion 8 of the upper die 15 and the bent portion 9 is set as small as possible. It is desirable to make it smaller.

However, if the angle α is reduced, the mechanical strength of the tip portion 15 is reduced, and the use as a press die is not sufficient. Therefore, conventionally, the angle α is manufactured and used at about 30 degrees. However, such a mold having a narrow angle cannot be used for a long time due to wear.
It becomes unusable in a short time.

In the next step (f), a bending process is performed in which the bent portion 9 is vertically bent so as to be in contact with the outer surface of the side wall portion 8. In this case, the bent portion 9 is rotated about its lower end. It needs to be shaped to However, in order to allow this rotation, the upper end of the bent portion 9 cannot be held down. Therefore, the height of the bent portion 9 after the forming process, that is, the curl height varies. When such variation increases,
The height correcting operation performed in the step (f) is troublesome.

[0012]

SUMMARY OF THE INVENTION It is an object of the present invention to extend the life of a press die for curling and to reduce variations in curl height.

[0013]

SUMMARY OF THE INVENTION The present invention comprises a step of drawing a flange around the periphery of a blank and an inclined portion, a step of trimming the periphery of the flange, and a step of preliminarily trimming the periphery of the trimmed flange. A first curling step of forming a bent portion by bending into a bent portion, a second curling step of pressing the bent portion preliminarily bent by the first curling step so as to be vertical, Form a rib on top and tilt it
Forming the lower part of the part vertically so as to press against the inner surface of the bent part which is made vertical first.

[0014]

In the first curling step, the rib has not been formed yet. The curling at this time is performed by a press die that contacts the outer surface of the inclined portion.
Therefore, the angle of the tip of the mold for this press can be made sufficiently wide, and its mechanical strength is sufficiently maintained.

After the second curling step, the ribs are formed, and the lower part of the slope is formed vertically. At that time, the bent portion has already been formed vertically by the second curling step, and its height is as specified.
Therefore, the curl height does not change due to the forming step after the second curling step.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
FIG. 1 shows the manufacturing process of the present invention. First, a circular blank 11 is cut into a required size from a plate material (process a) as in the conventional case. And the main body part 1 which becomes the sealing plate main body
While bending the periphery of 2 to form the inclined portion 8A,
The flange 13 is drawn at the tip of the inclined portion 8A (step b).

Next, after the flange 13 is cut to a predetermined length and trimmed (step c), the outer end of the remaining flange 13 is curled and preliminarily bent upward (step d). The bent portion 9 is formed by performing the second curling (step e) so that the end portion bent in this way is upright. Next, the lower end of the inclined portion 8A is erected until it comes into contact with the bent portion 9, and the rib 6 is formed on the upper end of the inclined portion 8A (step f), and then the height is corrected (step g). Complete.

FIG. 2 shows a molding state in step d. The lower end of the inclined wall portion 8A is preliminarily bent upward by the lower die 17 and the upper die 18. In this case, the angle α of the distal end portion 19 of the upper mold 18 which is pressed and inserted between the inclined portion 8A and the bent portion 9 is sufficiently larger than the angle α shown in FIG. Can be taken widely. Therefore, the tip portion 19 can maintain sufficient mechanical strength and can withstand long-term use.

FIG. 3 shows a molding state in the second curling step (step e). In this step, the lower mold 20 and the upper mold 21 are formed so that the bent portion 9 becomes vertical. In this case, since the distal end portion 22 of the upper mold 21 is interposed between the inclined portion 8A and the bent portion 9, the height of the bent portion 9, that is, the curl height becomes the predetermined size, and almost no variation occurs. do not do. Although the angle of the distal end portion 22 is small, it is only inserted between the inclined portion 8A and the bent portion 9 and there is no particular problem because the pressing force for molding does not act here.

FIG. 4 shows a molding state in a molding step (step f). In this step, the lower mold 23 and the upper mold 24 form the rib 6 on the upper end of the inclined portion 8A,
The lower end of the inclined portion 8A is erected at a right angle to make contact with the bent portion 9. Thereafter, through the process g, the sealing plate 5 is completed.

[0021]

As described above, according to the present invention, a mold used for curling can be used for a long time in manufacturing a coin-type battery sealing plate, as compared with the conventional method. In addition, there is an effect that the curl height can be manufactured with less variation.

[Brief description of the drawings]

FIG. 1 is a front view showing a process of an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a molding state in step d of FIG.

FIG. 3 is a sectional view showing a molding state in a step e of FIG. 1;

FIG. 4 is a cross-sectional view showing a molding state in a process f of FIG. 1;

FIG. 5 is a front view showing steps of a conventional method.

FIG. 6 is a cross-sectional view showing a molding state in step e of FIG. 5;

FIG. 7 is a front view showing a right half of the coin-type battery in cross section.

[Explanation of symbols]

 Reference Signs List 5 sealing plate 6 rib 7 peripheral portion 9 bent portion 8A inclined portion 11 blank 12 main body portion 13 flange

Claims (1)

(57) [Claims] A step of drawing a flange around the periphery of the blank and a flange thereof, a step of trimming the periphery of the flange, and a step of preliminary bending the periphery of the flange trimmed in the trimming step. A first curling step of forming a bent portion by pressing, a second curling step of pressing the bent portion preliminarily bent by the first curling step to be vertical,
A rib is formed on the upper part of the inclined portion of the blank.
Forming a vertical portion so that the lower portion of the inclined portion is pressed against the inner surface of the bent portion which has been made vertical first.