JP2000285875A - Manufacture of cylindrical battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a cylindrical battery of high energy density of power generating element per unit volume excellent in reliability, sealing pressure resistance and liquid leakage resistance. SOLUTION: In this manufacturing method, an electrode 2 is stored in a battery case 1 having an outer diameter D larger than a predetermined outer diameter (d) when completed, and the electrode 2 is formed by spirally winding positive and negative electrodes interposing a separator 7 therebetween. Then, an upper part is reduced in the diameter to have the predetermined outer diameter (d) respective to the electrode 2 storing part in the battery 1. An electrolyte is injected into the battery case 1. A seal 8 is inserted into the upper part having the predetermined outer diameter (d) for the battery case 1 and the opening is sealed. Finally, all the parts not yet to be in the diameter in the battery case 1 are reduced to have the predetermined outer diameter (d).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a cylindrical battery having a power generating element housed in a bottomed cylindrical battery case.

[0002]

2. Description of the Related Art With the spread and progress of various portable electronic devices such as notebook personal computers, portable telephones and video cameras, batteries having high performance, high safety and high reliability are desired as power sources for driving them. As batteries satisfying such requirements, nickel-metal hydride batteries and lithium-ion secondary batteries have attracted particular attention. That is, since these batteries have features such as high energy density, low self-discharge, and extremely long storage life, they can greatly contribute to the reduction in size and weight of portable electronic devices.

[0003] Such a battery has, for example, a structure as shown in FIG. That is, FIG. 1 shows a cylindrical battery externally covered with a bottomed cylindrical battery case 1, and the battery case 1 also serves as a negative electrode terminal. In the battery case 1, a separator 7 is interposed between a strip-shaped positive electrode plate 3 having a positive electrode active material and a strip-shaped negative electrode plate 4 having a negative electrode active material.
The negative electrode plate 4 and the positive electrode plate 3
The electrode body 2 which is arranged outside and is spirally wound is housed. The electrode body 2 forms a power generating element together with an electrolyte (not shown) injected into the battery case 1.

An opening at the upper end of the battery case 1 is provided with a sealing body 8 composed of a closing lid plate 9, a rubber valve body 10 of a safety valve, and an external terminal plate 11 (usually also serving as a positive electrode terminal). An annular gasket 12 is interposed between the annular support portion 14 bulged inward by the annular groove 13 formed on the surface, and is placed and supported. The peripheral edge of the opening at the upper end of the battery case 1 is bent inward and caulked. Thereby, it is sealed in a liquid-tight manner.

[0005] In manufacturing the above-mentioned cylindrical battery,
The outer diameter of the spiral electrode body 2 is set slightly smaller than the inner diameter of the battery case 1 so that it can be smoothly inserted into the battery case 1. This is because the outer peripheral portion of the electrode body 2 is rubbed against the inner peripheral surface of the battery case 1 when inserting the electrode body 2 into the battery case 1 whose outer shape is not necessarily a perfect circle because of the spiral shape. This is to prevent the collapse of the board. In this case, since a small gap is formed between the inner peripheral surface of the battery case 1 and the electrode body 2, the electrode body 2 is loosened, and the degree of tightness between the positive and negative electrode plates 3 and 4 is reduced. Therefore, the storage capacity of the power generation element per unit volume is reduced, and the energy density is reduced. On the other hand, a method of taping the outer peripheral portion of the spirally wound electrode body 2 to maintain the degree of tightness has been proposed. In this case, however, the inner circumferential surface of the battery case 1 and the electrode body 2 Is maintained as it is, the electrode body 2 swings in the battery case 1 to cause another problem such as tearing of a lead piece, and the reliability as a battery is reduced.

In order to solve the above-mentioned problem, a conventional swaging method (a pair of dies that reciprocate in a direction of coming and going while rotating) has been proposed.
A method of manufacturing a cylindrical battery by reducing the diameter of the battery case 1 by intermittently tapping and squeezing the outer peripheral surface from both sides (see JP-A-10-27584). In this cylindrical battery, the battery case 1 is formed to have an outer diameter slightly larger than a predetermined outer diameter when the battery is completed, and after a required amount of the electrode body 2 is stored in the battery case 1, The gap between the inner peripheral surface of the battery case 1 and the electrode body 2 is eliminated by reducing the diameter of only the storage location of the electrode body 2 in the battery case 1 to a predetermined outer diameter. The formation of the annular groove 13, the injection of the electrolytic solution and the insertion of the sealing body 8 are sequentially performed, and the sealing body 8 of the battery case 1 is housed in a state where the upper end opening of the battery case 1 is not sealed by the sealing body 8. Sealing the battery case 1 by reducing the diameter of the vicinity of the opening to a predetermined outside diameter, and finally bending and crimping the peripheral edge of the reduced diameter of the battery case 1 inward. It is manufactured through

In the above cylindrical battery, since the electrode body 2 is inserted into the battery case 1 formed to have an outer diameter larger than a predetermined outer diameter at the time of completion of the battery, the diameter of the electrode body 2 is made as large as possible. However, the battery case 1 can be smoothly inserted into the battery case 1, and the gap between the inner peripheral surface of the battery case 1 and the electrode body 2 is eliminated by reducing the diameter of the battery case 1. The effect that the degree does not decrease can be obtained. However, since the storage location of the electrode body 2 in the battery case 1 is reduced to a predetermined outer diameter, and the gap between the inner peripheral surface of the battery case 1 and the electrode body 2 is eliminated, the electrolytic solution is injected. It becomes difficult to inject the required amount of electrolyte. On the other hand, even if the required amount of the electrolyte is forcibly injected by using a means for applying pressure to the electrolyte and injecting the electrolyte, the opening at the upper end of the battery case 1 is not sealed by the sealing body 8. When the diameter near the opening of the battery case 1 is reduced, the electrolytic solution jumps out of the opening of the battery case 1. Therefore, the cylindrical battery obtained by the above manufacturing method has a problem that the life of the charge / discharge cycle is shortened due to the shortage of the electrolyte.

In the case where the diameter of the battery case 1 is reduced by the above-mentioned swaging method, for example, it takes approximately 4 seconds to reduce the diameter of the battery case 1 having a length of about 50 mm by 0.6 mm. The productivity is low, and it is difficult to apply pressure evenly to the entire outer peripheral surface of the battery case 1. Therefore, the roundness of the battery case 1 after diameter reduction is low, and the quality as a battery deteriorates. There is also the disadvantage of doing.

Apart from the above, conventionally, FIGS.
(Japanese Patent Publication No. 62-409818) has also been proposed. A method for producing a cylindrical battery through the steps shown in FIG.

FIGS. 1A and 1B show a groove forming step for forming an annular groove 13 at a predetermined position on the outer peripheral surface of the battery case 1. FIG. The battery case 1 is formed to have an outer diameter D slightly larger than a predetermined outer diameter d when the battery is completed, and the electrode body 2 is housed in the battery case 1. Accordingly, while the electrode body 2 is spirally wound so as to have a diameter as large as possible corresponding to the outer diameter D, it is easily inserted so that the electrode plate does not collapse in the battery case 1. it can. At this time, there is a small dimension s between the inner peripheral surface of the battery case 1 and the electrode body 2.
Gap 20 exists.

The battery case 1 accommodating the electrode body 2 is supported by fitting a lower part of the battery case 1 into a rotatable holder base 17, and a middle die 18 is provided at an upper end opening of the battery case 1 as shown in FIG. Fit into. Next, a groove forming roller 19 is pressed against a predetermined portion of the outer peripheral surface of the battery case 1 while rotating, and as shown in FIG.
The battery case 1 is rotated by the holder base 17 and the middle die 18. Accordingly, an annular groove 13 is formed on the outer peripheral surface of the battery case 1, and an annular support portion 14 swelled by the formation of the annular groove 13 is formed on the inner peripheral surface of the battery case 1.

Subsequently, as shown in FIG. 1C, an electrolyte 21 is injected into the battery case 1 through an injection tube 26.
At this time, since the battery case 1 is held at the large outer diameter D, a required amount of the electrolyte solution 21 can be easily injected.

Next, a sealing step shown in (d) and (e) is performed. First, the sealing body 8 shown in FIG. 4 is inserted into the battery case 1 and placed on the annular support portion 14. Subsequently, when the sealing mold 22 is moved downward toward the upper end of the battery case 1, the peripheral edge of the opening of the battery case 1 extends along the processing guide surface 22 a which is the inclined surface of the sealing mold 22. While being bent inward, the sealing mold 22
The sealing body 8 is swaged by the swaging surface 22b, and the opening of the battery case 1 is temporarily sealed by the sealing body 8. That is, since the portion of the battery case 1 for storing the sealing body 8 is caulked with a large outer diameter D, there is a slight gap between the battery case 1 and the sealing body 8. Thus, the opening of the battery case 1 is temporarily sealed so as not to be completely sealed.

Finally, a diameter reduction step shown in FIGS. 6F and 6G is performed. The battery case 1 whose upper end opening is temporarily sealed by the sealing body 8 is a substantially cylindrical shape that moves upward while the upper end including the sealing body 8 is supported by the holding support 23 in a suspended state. It is inserted inside the diameter reducing device 24. A substantially cylindrical outer body box 2 in the diameter reducing device 24
As shown in (f), a diameter reducing mold 27 for reducing the diameter of the battery case 1 to a predetermined outer diameter d is removably fitted into the inner peripheral surface of the inner peripheral surface of the inner diameter surface of the inner diameter surface of the inner diameter surface of the inner diameter surface of the mold 5 as shown in FIG. 27 is fixed by a fixture 28. Therefore, when the battery case 1 has passed through the inside of the diameter reducing mold 27, the entire lengthwise direction of the battery case 1 is reduced to a predetermined outer diameter d by the diameter reducing mold 27 as shown in (g). Diameter. By reducing the diameter of the battery case 1 to a predetermined outer diameter d in this manner, the gap 20 between the inner peripheral surface of the battery case 1 and the electrode body 2 is eliminated, and the looseness of the electrode body 2 reduces the degree of tightness. Is prevented from occurring.

[0015]

However, in the above-described method for manufacturing a cylindrical battery, as shown in FIG.
After a required amount of the electrode body 2 and the electrolytic solution are accommodated in the battery case 1 having the outer diameter D larger than the predetermined outer diameter d, the upper end opening is temporarily closed with the sealing body 8. Since the whole is reduced to a predetermined outer diameter d along its longitudinal direction, if the reduced diameter [(D−d) ÷ 2] is set relatively large to 0.2 mm or more, FIG. As shown in the figure, the location of the annular groove 13 in the battery case 1 is
It buckles under the pressure at the time of diameter reduction and transforms into a hanging state. Along with this deformation, there is a disadvantage that the insulating gasket 12 is deformed away from the sealing body 8.

Therefore, the electrolytic solution 21 existing in the gap 20 between the inner peripheral surface of the battery case 1 and the electrode body 2 is pushed upward as the diameter of the battery case 1 is reduced upward from the bottom. When it is removed, a part thereof enters the gap existing between the sealing body 8 and the insulating gasket 12 deformed away from the sealing body 8 or between the inner peripheral surface of the battery case 1 and the insulating gasket 12, Since the infiltrated electrolyte solution 21 becomes a passage for leakage, the leakage resistance is significantly reduced.

On the other hand, the periphery of the opening of the battery case 1 which holds the sealing body 8 is reduced in diameter after the caulking of the sealing body 8 is completed, and the sealing body 8 also reduces the pressure at the time of diameter reduction. Since it is deformed by receiving, the pressure-resistant function of the sealing member 8 for sealing is deteriorated, and as a result, the leakage resistance is reduced. Therefore, the cylindrical battery manufactured by the above manufacturing method has a problem that the sealing pressure resistance and the liquid leakage resistance are significantly reduced.

Accordingly, the present invention has been made in view of the above-mentioned conventional problems, and is intended to produce a cylindrical battery having a high energy density of a power generating element per unit volume, and excellent in reliability, sealing pressure resistance, and liquid leakage resistance. It is an object of the present invention to provide a method capable of performing such operations.

[0019]

In order to achieve the above object, a method of manufacturing a cylindrical battery according to the present invention comprises an electrode plate wound spirally with a separator interposed between a positive electrode plate and a negative electrode plate. Is stored in a battery case formed with an outer diameter larger than a predetermined outer diameter at the time of completion of the battery; and An upper diameter reducing step of reducing the diameter, an injecting step of injecting an electrolytic solution into the battery case, and a sealing step of inserting a sealing body into an upper part having a predetermined diameter of the battery case to seal the opening. And a step of reducing the diameter of the entire unreduced diameter portion of the battery case to a predetermined outer diameter.

According to this method of manufacturing a cylindrical battery, an electrode body having a diameter as large as possible can be accommodated in a battery case having an outer diameter larger than a predetermined outer diameter at the time of completion of the battery without causing collapse of the electrode plate. It can be easily stored and easily injected with a required amount of electrolyte, and the battery case is reduced in diameter to a predetermined outer diameter to eliminate the gap between the inner peripheral surface of the battery case and the electrode body. A cylindrical battery with high energy density per volume and high reliability can be obtained.

In addition, the upper part of the battery case is reduced in diameter to a predetermined outer diameter with respect to the storage part of the electrode body.
After the opening of the battery case is sealed in a regular sealed state by the sealing body, the storage location of the electrode body in the battery case is reduced to a predetermined outer diameter. Has no external force,
There is no deformation or the like, and a high sealing pressure when the opening peripheral portion of the battery case is swaged and sealed is maintained as it is.

Further, since the sealing body is not deformed in the diameter reduction step, the annular groove is deformed to expand inward due to the external force at the time of diameter reduction, but the contact point with the insulating gasket in the battery case is reduced. Then, the contact angle before the diameter reduction processing is maintained, and the state of being in close contact with the insulating gasket is maintained as it is. Therefore, the cylindrical battery manufactured by this manufacturing method is an excellent one that can ensure both high sealing pressure resistance and liquid leakage resistance.

In the above invention, after the upper diameter reducing step, an annular groove is formed in an outer peripheral surface of an upper portion having a predetermined outer diameter by the diameter reduction, and an annular groove is supported on an inner peripheral surface of the battery case. It is preferable to perform a grooving step for forming the support.

Thus, since the annular groove is formed at a portion of the battery case where the diameter is reduced to a predetermined outer diameter, after the annular groove is formed at a portion of the battery case having a large outer diameter, the battery case is moved to the predetermined outer diameter. The buckling does not cause the shape to hang down as in the case where the diameter is reduced.

Further, in the battery case diameter reducing step according to the above invention, the outer diameter is reduced to a predetermined outer diameter while the outer diameter is gradually reduced by repeating a plurality of times for the unreduced diameter portion of the battery case. Is preferred.

Thus, the diameter of the battery case can be extremely smoothly reduced to a predetermined outer diameter, the deformation of the annular groove in the battery case can be further reduced, and the contact area between the battery case and the insulating gasket can be sealed. Since the contact state during processing can be more reliably maintained, the sealing pressure resistance and liquid leakage resistance can be further improved.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. 1 and 2 are process diagrams sequentially showing the manufacturing steps in the method for manufacturing a cylindrical battery of the present invention. FIGS. 1 (a) and 1 (b) show an upper diameter reduction step, and FIGS. 1 (c) and 1 (d). 2 (e) shows a liquid filling step, FIGS. 2 (f) and 2 (g) show a sealing step, and FIGS. 2 (h) and 2 (i) show a diameter reduction step.

First, as shown in FIG. 1A, the battery case 1 is formed to have an outer diameter D slightly larger than a predetermined outer diameter d when the battery is completed. Is inserted and stored. Therefore, the electrode body 2 is wound spirally so as to have a diameter as large as possible corresponding to the outer diameter D to increase the capacity, but easily without the electrode plate collapsing in the battery case 1. Can be inserted. At this time, a gap 20 having a small dimension s exists between the inner peripheral surface of the battery case 1 and the electrode body 2.

When the diameter of the upper portion near the opening of the battery case 1 is reduced, the battery case 1 containing the electrode body 2 is supported by fitting the lower portion thereof to a rotatable holder base 17. As shown in (b), the upper part of the battery case 1 near the opening is lowered and fitted by the upper diameter reducing device 29 as shown by the arrow, as shown in FIG.
The diameter is reduced to a predetermined outer shape d when the battery is completed.

That is, the upper diameter reducing device 29 is provided on the inner peripheral surface of a headed cylindrical outer body box 30 with a drawing portion 31 having a diameter to reduce the upper portion of the battery case 1 to a predetermined outer diameter d.
a and a diameter reducing mold 31 having an inclined processing guide surface 31b is fitted and fixed, and has an outer diameter d.
A pressing core 32 having a pressing surface 32a formed at a lower portion having a diameter substantially the same as that of the pressing core 32 is slidably housed in the outer body box 30 and is located above the pressing core 32 inside the outer body box 30. The configuration is such that the coil spring 33 is housed in the location.

Accordingly, the upper part of the battery case 1 is inserted into the outer body box 30 with the downward movement of the upper diameter reducing device 29, and then bent inward along the processing guide surface 31b of the diameter reducing mold 31. And the upper end portion is drawn part 31a.
The diameter is reduced to a predetermined outer diameter d regulated by the above. When the upper diameter reducing device 29 moves down to the lower limit position, as shown in (b), the upper surface of the battery case 1 has its open end face pressed by the pressing surface 32 a of the pressing core 32 by the urging force of the coil spring 33. Pressed in the direction. When the upper diameter reducing device 29 rises, the pressing core 32 presses the upper end of the battery case 1 downward by the urging force of the coil spring 33, and the battery case 1
Departed from 1.

Next, an annular groove 13 is formed in the battery case 1 whose upper part is reduced in diameter to a predetermined outer diameter d through the steps shown in FIGS. That is, the middle die 1 is inserted into the upper end opening of the battery case 1 whose diameter is reduced to a predetermined outer diameter d.
8 is fitted as shown in FIG. Next, a groove forming roller 9 is provided at a predetermined location on the outer peripheral surface of the battery case 1.
Is pressed while rotating, and the battery case 1 is rotated by the holder base 17 and the middle mold 18 as shown in FIG. Thus, an annular groove 13 is formed on the outer peripheral surface of the battery case 1, and an annular support portion 14 swelled by the formation of the annular groove 13 on the inner peripheral surface of the battery case 1.
Is formed. Here, the annular groove 13 is formed in a predetermined shape corresponding to the sealing body 8 at an intermediate portion between an upper portion reduced in diameter to a predetermined outer diameter d and a portion having a large outer diameter D in the battery case 1.

Subsequently, the electrolyte 21 is injected into the battery case 1 through the injection tube 26 as shown in FIG.
At this time, since the storage location of the electrode body 2 in the battery case 1 is maintained at the large outer diameter D, a required amount of the electrolyte 21 can be easily injected.

Next, a sealing step shown in FIGS. 2F and 2G is performed. First, as shown in (f), the sealing body 8 shown in FIG. Put on. Subsequently, when the sealing mold 34 is moved down toward the upper end of the battery case 1, the battery case 1
Is bent inward along the processing guide surface 34a which is the inclined surface of the closing mold 34, and is swaged on the sealing body 8 by the swaging surface 34b of the closing mold 34. It is processed and the opening of the battery case 1 is sealed by the sealing body 8. In this sealing step, only the upper portion of the battery case 1 that is sealed by the sealing body 8 is reduced in diameter to a predetermined outer diameter d when the battery is completed, and the annular support formed in the portion having the predetermined outer diameter d is formed. Since the sealing is performed while the sealing member 8 is supported by the part 14, unlike the temporary sealing in the sealing step of FIGS. 5 (d) and 5 (e) in the conventional method,
The opening of the battery case 1 is sealed in a regular closed state when the battery is completed.

Finally, a diameter reduction step shown in (h) and (i) is performed. The battery case 1 whose upper end opening is sealed by the sealing member 8 holds the upper end portion including the sealing member 8 and supports 37.
While being supported in a suspended state by the above, it is inserted into the inside of a generally cylindrical diameter reducing device 24 that moves upward. As shown in (h), a diameter reducing mold 27 for reducing the diameter of the battery case 1 to a predetermined outer diameter d is provided on the inner peripheral surface of the substantially cylindrical outer body box 25 in the diameter reducing device 24. The diameter-reducing mold 27 is fixed by a fixture 28. The diameter reducing mold 27 integrally includes a drawing portion 27a having a diameter for reducing the diameter of the battery case 1 to a predetermined outer diameter d and a processing guide surface 27b which is an inclined surface. Therefore, when the battery case 1 has passed through the inside of the diameter reducing mold 27, as shown in FIG.
The diameter is reduced to Thus, the battery case 1 has a predetermined outer diameter d.
By reducing the diameter, the gap 20 between the inner peripheral surface of the battery case 1 and the electrode body 2 is eliminated, so that the looseness of the electrode body 2 does not reduce the degree of tightness.

As shown in FIG. 3 (a), the above-described step of reducing the diameter of the battery case is performed in a state where the upper portion of the battery case 1 is reduced in diameter to a predetermined outer diameter d and the opening is sealed by the sealing body 8. It is only performed for the storage location of the electrode body 2 in the case 1. Therefore, the sealing body 8 in the battery case 1
Is simply inserted into the drawn portion 27a of the diameter reducing mold 27, and the storage location of the sealing body 8 and the sealing body 8 in the battery case 1 are not subjected to any external force, and thus may be deformed. And the high sealing pressure resistance when the peripheral edge of the opening of the battery case 1 is sealed by caulking in the above-described sealing step is maintained.

Also, in this diameter reducing step, since the sealing portion of the battery case 1 with the sealing member 8 is not subjected to any external force, when the housing portion of the electrode body 2 in the battery case 1 is reduced in diameter, FIG. As shown in b), the annular groove 13 is deformed so as to expand inward due to the external force when the diameter is reduced, but the contact portion of the battery case 1 with the insulating gasket 12 is different from that in FIG. As is clear from FIG. 2, the contact angle of 180 ° before the diameter reduction processing is maintained, and the state of being in close contact with the insulating gasket 12 is maintained. Therefore, the cylindrical battery manufactured by this manufacturing method has a required amount of the electrode body 2.
And the electrolyte solution 21 are housed in the battery case 1, and the gap 20 is eliminated between the inner peripheral surface of the battery case 1 and the electrode body 2 to increase the energy density per unit volume, while maintaining high sealing pressure resistance. It is an excellent material that can secure both the liquid leakage resistance.

In the above diameter reduction step, the battery case 1
The internal pressure of the battery case 1 is sufficiently lower than the operating pressure of the safety valve constituted by the rubber valve body 10 or the like. There is no. For example, according to actual measurements, when manufacturing a AAA cylindrical battery having an outer diameter of 10 mm, the outer diameter D of the battery case 1 before reduction is 0.3 mm to 0.6 mm. While performing mm), the internal pressure of the battery case 1 to rise in the reduced diameter step is 4kg / cm ² ~5kg / cm ² or so, the operating pressure of the safety valve
It is set to about ^{15kg / cm 2 ~20kg / cm 2} .

FIG. 2 in the above embodiment.
In the diameter reduction steps (h) and (i), the case where the storage location of the electrode body 2 in the battery case 1 is reduced in one step by using a single diameter reduction device 24 is described. It is preferable that the battery case 1 is gradually reduced in diameter from the outer diameter D before the diameter reduction by repeating the diameter reduction step, and is reduced to a predetermined outer diameter d in the final diameter reduction step. is there. In each of the diameter reducing steps, a plurality of types of diameter reducing dies 27 in which the diameter of the drawing section 27a is sequentially reduced are replaced and mounted on the diameter reducing apparatus 24 each time.
Multiple kinds of diameter reducing dies 27 whose diameter of 7a is gradually reduced
Using a plurality of diameter reducing devices 24 individually mounted. By reducing the large outer diameter D of the battery case 1 to a predetermined outer diameter d by performing the diameter reducing step divided into a plurality of times in this manner, the deformation of the location where the annular groove 13 is formed in the battery case 1 is further reduced. As a result, the contact portion between the battery case 1 and the insulating gasket 12 can be kept in a close contact state during the sealing process, and the sealing pressure resistance and the liquid leakage resistance can be further improved.

[0040]

As described above, according to the method of manufacturing a cylindrical battery according to the present invention, the upper part of the battery case is reduced in diameter to a predetermined outer diameter with respect to the storage location of the electrode body in the battery case. Since the opening of the electrode body in the battery case is reduced to a predetermined outer diameter after the opening is sealed in a regular sealed state by the sealing body, the storage location of the sealing body in the battery case and the sealing body are reduced. Since there is no external force, no deformation or the like occurs, and the high sealing pressure resistance when the opening edge of the battery case is swaged and sealed is maintained.

In addition, since the sealing body does not deform in the diameter reducing step, the annular groove is deformed to expand inward due to the external force at the time of diameter reduction, and the contact point with the insulating gasket in the battery case is reduced. Then, the contact angle before the diameter reduction processing is maintained, and the state of being in close contact with the insulating gasket is maintained as it is.
Therefore, the cylindrical battery manufactured by this manufacturing method is an excellent one that can ensure both high sealing pressure resistance and liquid leakage resistance.

Further, an electrode body having a diameter as large as possible can be easily accommodated in a battery case having an outer diameter larger than a predetermined outer diameter at the time of completion of the battery without collapse of the electrode plate.
In addition, the required amount of electrolyte can be easily injected, and the battery case is reduced in diameter to a predetermined outer diameter to eliminate the gap between the inner peripheral surface of the battery case and the electrode body. In addition, a cylindrical battery having high reliability can be obtained.

[Brief description of the drawings]

FIGS. 1A and 1B are process diagrams sequentially showing a first half of a manufacturing process in a method for manufacturing a cylindrical battery of the present invention, wherein FIGS. 1A and 1B show an upper diameter reducing process, and FIGS. , (E) is the injection step.

FIG. 2 is a process chart sequentially showing the latter half of the manufacturing steps in the above manufacturing method, wherein (f) and (g) show a sealing step, and (h),
(I) is a diameter reduction step.

FIG. 3A is a longitudinal sectional view of a main part after a sealing step in the manufacturing method, and FIG. 3B is a longitudinal sectional view of a main part of the completed battery after a diameter reducing step.

FIG. 4 is a longitudinal sectional view showing a cylindrical battery manufactured by the method of the present invention.

FIGS. 5A and 5B are process diagrams sequentially showing the first half of a manufacturing process of a conventional cylindrical battery manufacturing method, wherein FIGS. 5A and 5B show a grooving process, FIG. 5C shows a pouring process, and FIGS. e) Sealing step.

FIG. 6 is a process chart of a diameter reducing step which is the last manufacturing step in the manufacturing method of the above.

FIG. 7A is a longitudinal sectional view of a main part after a sealing step in the above manufacturing method, and FIG. 7B is a longitudinal sectional view of a main part of the completed battery after a diameter reducing step.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery case 2 Electrode body 3 Positive electrode plate 4 Negative electrode plate 7 Separator 8 Sealing body 13 Annular groove 14 Annular support part 21 Electrolyte d Predetermined outer diameter D Large outer diameter

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H011 AA01 AA17 CC06 DD01 DD05 DD06 DD15 DD26 5H028 AA01 AA07 BB00 BB01 BB03 BB04 BB14 BB19 HH05

Claims (3)

[Claims] 1. A spirally wound electrode plate with a separator interposed between a positive electrode plate and a negative electrode plate is housed in a battery case formed with an outer diameter larger than a predetermined outer diameter when the battery is completed. An electrode body storing step, an upper diameter reducing step of reducing an upper part to a predetermined outer diameter with respect to a storing part of the electrode body in the battery case, and a pouring step of injecting an electrolytic solution into the battery case. A sealing step of inserting a sealing body into an upper portion having a predetermined diameter of the battery case to seal the opening, and a diameter reducing step of reducing the entire non-reduced diameter portion of the battery case to a predetermined outer diameter. And a method for producing a cylindrical battery. 2. An electrode body receiving step, an upper diameter reducing step, an annular groove is formed on an outer peripheral surface of an upper portion having a predetermined outer diameter by reducing the diameter, and a sealing member is formed on an inner peripheral surface of the battery case. A grooving step of forming an annular support portion for supporting the fins, and thereafter, a liquid injection step and a sealing step, and then a cylindrical cell is manufactured by a diameter reducing step. 3. The battery case according to claim 1, wherein, in the step of reducing the diameter of the battery case, the outer diameter is reduced to a predetermined outer diameter while the outer diameter is gradually reduced by repeating a plurality of times of reducing the diameter of the unreduced portion of the battery case. Item 3. The method for producing a cylindrical battery according to Item 1 or 2.