JP2012084265A - Cylindrical battery and cylindrical battery outer can - Google Patents

Abstract

PROBLEM TO BE SOLVED: To further increase the capacity of a cylindrical battery while maintaining the hardness of a sealing portion at such a level that liquid leakage does not occur.SOLUTION: A cylindrical battery outer can 10 is a component used for manufacturing a cylindrical battery 20, and constitutes an outer can 1 of the cylindrical battery 20 as a finished product. The cylindrical battery outer can 10 is manufactured by working a metal plate and has a cylindrical shape with a bottom 11 and an opening 12, that is, a bottomed cylindrical shape. The cylindrical battery outer can 10 comprises: an electrode body housing portion 13 in which an electrode body 2 serving as a power generation element is housed; a first cylindrical portion 14 which has a fixed thickness B greater than a thickness A of the electrode body housing portion 13, and which is connected closer to the opening 12 than the electrode body housing portion 13 is to the opening 12: and a second cylindrical portion 15 which has a fixed thickness C greater than the thickness B of the first cylindrical portion 14, and which is connected closer to the opening 12 than the first cylindrical portion 14 is to the opening 12.

Description

  The present invention is interposed between a bottomed cylindrical outer can, an electrode body housed in the outer can and serving as a power generation element, a sealing body that seals the opening of the outer can, and the outer can and the sealing body. The present invention relates to a cylindrical battery including a gasket and a cylindrical battery outer can.

  Cylindrical alkaline secondary batteries such as nickel metal hydride batteries and lithium ion batteries are known. In such a cylindrical battery, there is a growing demand for further increase in capacity and weight in recent years. Here, as a technique for realizing a large capacity of the cylindrical battery without changing the outer dimensions, for example, a technique for increasing the volume capable of accommodating the electrode body etc. by reducing the thickness of the outer can is given. It is done. However, in a general cylindrical battery in which the overall thickness of the outer can is uniform, if the thickness of the outer can is reduced, the strength of the caulking portion that seals the opening of the outer can decreases. For this reason, there is an increased risk of so-called liquid leakage in which the electrolyte inside the battery leaks to the outside.

  As a conventional technique for solving such a problem, for example, an outer can in which the thickness in the vicinity of the opening is made thicker than the thickness of the other portion, that is, an outer can whose thickness changes in two stages is used. Known cylindrical batteries are known (see, for example, Patent Document 1). According to the related art, the capacity of the cylindrical battery can be increased by increasing the volume of the outer can while maintaining the strength of the sealing portion at a level at which liquid leakage does not occur.

  In addition, as an example of the prior art of a cylindrical battery that employs an outer can with a non-uniform thickness, the purpose is completely different, for example, a taper in which the thickness gradually increases from the can bottom to the opening. Cylindrical batteries using a shaped outer can are known (see, for example, Patent Document 2). According to the related art, since the electrode body inside the outer can is firmly held at the portion where the thickness of the outer can is thick, the impact resistance of the cylindrical battery can be improved.

JP 05-114389 A JP 2002-216709 A

  However, for example, the cylindrical battery using the outer can whose thickness is disclosed in Patent Document 1 is changed in two stages, if the difference between the thickness in the vicinity of the opening and the thickness in the other part is too large, The rigidity imbalance of the outer can caused by the difference in the wall thickness becomes remarkable. For this reason, from the viewpoint of manufacturing technology, there are many cases where the outer can cannot be easily manufactured. Even if the outer can can be manufactured, the thickness of the outer can is thin due to the rigidity imbalance in press working and drawing when manufacturing the cylindrical battery using the outer can. The part is deformed, and there arises a problem that it cannot be formed into the original normal cylindrical battery shape. Therefore, the conventional technology disclosed in Patent Document 1 is constant in increasing the capacity of the outer can and increasing the capacity of the cylindrical battery while maintaining the strength of the sealing portion at a level at which liquid leakage does not occur. There are limits.

  In addition, for example, the cylindrical battery disclosed in Patent Document 2 has a structure in which the electrode body is held in that portion by increasing the thickness of the portion in which the electrode body of the outer can is accommodated. On the contrary, the volume of the portion in which the electrode body is accommodated decreases. Therefore, with the prior art disclosed in Patent Document 2, it is difficult to realize a large capacity of the cylindrical battery.

  Furthermore, the cylindrical battery disclosed in Patent Document 2 has a tapered shape in which the outer can gradually increases in thickness from the bottom of the can to the opening, so that the outer can is sealed against the sealing body that seals the opening. The inner peripheral surface of the can faces with an angle. That is, the gap between the sealing body that seals the opening and the inner peripheral surface of the outer can is not substantially equal, and a gradually changing width is generated. Therefore, the cylindrical battery disclosed in Patent Document 2 uniformly compresses the gasket interposed between the most important sealing body and the outer peripheral surface of the outer can in order to stably secure the sealing performance at the sealing portion. It becomes extremely difficult to obtain a state. Therefore, in the cylindrical battery disclosed in Patent Document 2, there is an increased risk of liquid leakage due to non-uniform compression of the gasket. In addition, the manufacturing tolerance of the outer can must be compressed and the compression rate of the gasket must be more strictly controlled, which may increase the manufacturing cost.

  The present invention has been made in view of such circumstances, and an object of the present invention is to realize a further increase in capacity while maintaining the strength of the sealing portion at a level at which liquid leakage does not occur in a cylindrical battery. .

<First Aspect of the Present Invention>
A first aspect of the present invention includes a bottomed cylindrical outer can, an electrode body serving as a power generation element, a sealing body that seals an opening of the outer can, and an intermediate between the outer can and the sealing body. A gasket to be mounted, and the outer can includes an electrode body housing portion in which the electrode body is housed, and a constant thickness that is greater than a thickness of the electrode body housing portion and is closer to the opening side than the electrode body housing portion. And a first cylindrical portion in which a first peripheral wall that supports the sealing body is formed inside by pressing, and a constant thickness that is thicker than a thickness of the first cylindrical portion, than the first cylindrical portion. A cylindrical battery characterized in that it includes a second cylindrical portion that is connected to the opening side and sandwiches the sealing body with the first peripheral wall and is formed inside by pressing. .

  That is, since the outer can of the cylindrical battery according to the present invention has a shape in which the thickness increases in three stages from the electrode body housing portion to the opening, the thickness of the electrode body housing portion and the sealing portion Even if the thickness and the difference are increased, the rigidity imbalance caused by the difference in the thickness can be reduced as compared with the conventional case. Therefore, it is possible to reduce the possibility that the outer can may be deformed due to the rigidity imbalance in the press working or drawing process when manufacturing the cylindrical battery. As a result, the cylindrical battery according to the present invention can achieve a further increase in capacity by increasing the volume of the outer can than in the past while maintaining the strength of the sealing portion at a level at which liquid leakage does not occur.

  In the outer can of the cylindrical battery according to the present invention, the thickness of the first cylindrical portion is constant, and the thickness of the second cylindrical portion is also constant. Therefore, since the inner peripheral surface of the first cylindrical portion and the second cylindrical portion and the sealing body face each other substantially in parallel, the inner peripheral surface of the first cylindrical portion and the second cylindrical portion and the sealing body are between them. It is possible to easily put the interposed gasket in a substantially uniformly compressed state. Therefore, the cylindrical battery according to the present invention can extremely reduce the possibility of liquid leakage from the sealing portion due to a decrease in sealing strength due to non-uniformity of the compressed state of the gasket.

  As a result, according to the first aspect of the present invention, in the cylindrical battery, there is obtained an effect that a further increase in capacity can be realized while maintaining the strength of the sealing portion at a level at which liquid leakage does not occur. .

<Second Aspect of the Present Invention>
A second aspect of the present invention is a cylindrical battery outer can having a bottomed cylindrical shape, and includes an electrode body housing portion in which an electrode body serving as a power generation element is housed, and a thickness of the electrode body housing portion. A first cylindrical portion connected to the opening side from the electrode body housing portion with a constant thickness, and a constant thickness larger than the thickness of the first cylindrical portion, connected to the opening side from the first cylindrical portion. A cylindrical battery outer can comprising a second cylindrical portion provided.
According to the second aspect of the present invention, in the cylindrical battery manufactured using this cylindrical battery outer can, the same effects as those of the first aspect of the present invention described above can be obtained.

<Third Aspect of the Present Invention>
According to a third aspect of the present invention, there is provided the cylindrical battery outer can according to the second aspect of the present invention, wherein the inner diameter is uniformly formed from the bottom to the opening.
According to the 3rd aspect of this invention, in addition to the effect by the 2nd aspect of this invention mentioned above, the effect that the operation | work which accommodates an electrode body in an electrode body accommodating part can be performed easily is acquired. It is done.

  According to the present invention, in the cylindrical battery, it is possible to realize further increase in capacity while maintaining the strength of the sealing portion at a level at which liquid leakage does not occur.

The side sectional view of the cylindrical battery exterior can and cylindrical battery concerning the present invention. The sectional side view which illustrated the seam putting process of the manufacturing process of a cylindrical battery. The sectional side view which illustrated the 1st press work process of the manufacturing process of a cylindrical battery. The sectional side view which illustrated the 2nd press work process of the manufacturing process of a cylindrical battery. The sectional side view which illustrated the press bonding process of the manufacturing process of a cylindrical battery. The sectional side view which illustrated the outer diameter drawing process of the manufacturing process of a cylindrical battery. The sectional side view which illustrated the outer can for cylindrical batteries and the cylindrical battery of the comparative example.

<Cylindrical battery according to the present invention, outer can for cylindrical battery>
The structure of the cylindrical battery 20 and the cylindrical battery outer can 10 according to the present invention will be described with reference to FIG. FIG. 1 is a side sectional view of a cylindrical battery outer can 10 (FIG. 1A) and a cylindrical battery 20 (FIG. 1B) according to the present invention.

  The cylindrical battery outer can 10 is a component used for manufacturing the cylindrical battery 20, and constitutes the outer can 1 in the cylindrical battery 20 as a finished product. The cylindrical battery outer can 10 is manufactured by processing a metal plate, and has a cylindrical shape having a bottom 11 and an opening 12, that is, a bottomed cylindrical shape. The cylindrical battery outer can 10 includes an electrode body housing portion 13 in which the electrode body 2 serving as a power generation element is housed, and a constant thickness B that is thicker than the wall thickness A of the electrode body housing portion 13 from the electrode body housing portion 13. The first cylindrical part 14 provided continuously on the opening 12 side, and the second cylindrical part provided continuously on the opening 12 side from the first cylindrical part 14 with a constant thickness C greater than the thickness B of the first cylindrical part 14. 15.

  The cylindrical battery outer can 10 is shaped so that the inner diameter is constant from the bottom 11 to the opening 12. This is not an essential component of the present invention, but it has such a shape in that the operation of housing the electrode body 2 in the electrode body housing portion 13 of the cylindrical battery outer can 10 can be easily performed. It is preferable to do this.

  The cylindrical battery 20 includes a bottomed cylindrical outer can 1, an electrode body 2 serving as a power generation element, a sealing body 3 that seals the opening 12 of the outer can 1, and the outer can 1 and the sealing body 3. And an interposed gasket 4. The outer can 1 of the cylindrical battery 20 includes an electrode body housing portion 13 in which the electrode body 2 is housed and a constant thickness B that is thicker than the wall thickness A of the electrode body housing portion 13 and the opening 12 side from the electrode body housing portion 13. And a first cylindrical portion 14 in which a first peripheral wall 16 that supports the sealing body 3 is formed inside by pressing, and a first thickness C is greater than a thickness B of the first cylindrical portion 14. A second peripheral wall 17 is provided which is connected to the opening 12 side of the cylindrical portion 14 and sandwiches the sealing body 3 with the first peripheral wall 16 and is formed inside by pressing.

  The electrode body 2 is an electrode group (not shown) in which, for example, a separator interposed between an anode plate and a cathode plate is wound in a spiral shape. The sealing body 3 includes a valve mechanism (not shown) that maintains the internal pressure of the outer can 1 at a predetermined pressure or lower, and a substantially disc-shaped base is sandwiched between the first peripheral wall 16 and the second peripheral wall 17. And attached to the outer can 1. Further, the sealing body 3 is electrically connected to the anode plate of the electrode body 2 by a lead wire (not shown), and also functions as an electrode (+ electrode) of the cylindrical battery 20. The gasket 4 is a substantially ring-shaped member made of an insulating and elastic material, and a base portion having a substantially U-shaped cross-section is compressed between the first peripheral wall 16 and the second peripheral wall 17 and the sealing body 3. In this state, the sealed state inside the outer can 1 is stably maintained to prevent liquid leakage.

  As described above, the outer can 10 of the cylindrical battery and the outer can 1 of the cylindrical battery 20 according to the present invention have three stages in which the thickness increases in three stages from the electrode body housing portion 13 to the opening 12. It has a cylindrical shape. Here, the difference between the wall thickness B of the first cylindrical portion 14 and the wall thickness C of the second cylindrical portion 15 with respect to the wall thickness A of the electrode body housing portion 13 is greater while ensuring a larger volume of the electrode body housing portion 13. In order to achieve a high sealing strength, it is preferable to set the cylindrical battery outer can 10 as large as possible within a range in which the cylindrical battery can 10 can be manufactured. For example, the thickness B of the first cylindrical portion 14 is set to a thickness of about 101 to 150% with respect to the thickness A of the electrode body housing portion 13, and the thickness C of the second cylindrical portion 15 is set to the thickness B. It is preferable to set the thickness to about 131 to 200% with respect to the thickness A of the electrode body housing portion 13 after making the thickness thicker. In particular, the thickness B of the first cylindrical portion 14 is set to a thickness of about 135% with respect to the thickness A of the electrode body housing portion 13, and the thickness C of the second cylindrical portion 15 is set to the thickness of the electrode body housing portion 13. It is more preferable to set the thickness to about 160% with respect to the thickness A.

<Method for manufacturing cylindrical battery>
A method for manufacturing the cylindrical battery 20 will be described with reference to FIGS. The cylindrical battery 20 is manufactured through a seam putting process, a first press working process, a second press working process, a pressure press working process, and an outer diameter drawing process described below.

  The cylindrical battery outer can 10 shown in FIGS. 2 to 6 has a substantially constant thickness on the drawing in order to make the drawing easier to see, but the meat shown in FIG. This is the same as the cylindrical battery outer can 10 having three different thicknesses. 2 to 6, the electrode body 2, the sealing body 3, the gasket 4, and the cylindrical battery outer can 10 are not shown hatched for easier viewing.

FIG. 2 is a side sectional view illustrating the seam insertion process.
First, the electrode body 2 is accommodated in the electrode body accommodating portion 13 of the cylindrical battery outer can 10. Subsequently, a seam 10a (shelf) is formed at a predetermined position of the first cylindrical portion 14 by grooving or the like that linearly presses the outer peripheral surface of the first cylindrical portion 14 of the cylindrical battery outer can 10. The seam 10 a becomes the first peripheral wall 16. Subsequently, after a predetermined amount of electrolytic solution (not shown) is filled in the electrode body housing part 13, the sealing body 3 and the gasket 4 are placed on the seam 10a (first peripheral wall 16) as shown in the figure.

  FIG. 3 is a sectional side view illustrating the first press working step.

  Subsequently, the cylindrical battery outer can 10 after the seam inserting step is attached to the caulking split mold 21. The caulking split mold 21 is a substantially annular split mold, and a convex portion 211 that engages with the seam 10a of the cylindrical battery outer can 10 is formed on the inner peripheral surface over the entire circumference. The convex portion 211 supports the seam 10a of the cylindrical battery outer can 10 from below. Subsequently, the second cylindrical portion 15 of the cylindrical battery outer can 10 is pressed downward P from the opening end side by the first press die 22. As for the 1st press type | mold 22, the circular recessed part 221 of a substantially conical cross-sectional shape is formed in the center of the bottom face. When the second cylindrical portion 15 of the cylindrical battery outer can 10 is pressed against the slope of the circular recess 221 of the first press die 22, the vicinity of the boundary with the first cylindrical portion 14 is obliquely bent inward. Strong pressure molding with a crease. Thereby, the sealing body 3 and the gasket 4 are fixed.

FIG. 4 is a sectional side view illustrating the second press working process.
Subsequently, the second cylindrical portion 15 of the cylindrical battery outer can 10 is opened by the second press mold 23 while the cylindrical battery outer can 10 after the first press working is attached to the caulking split mold 21. Press from side to bottom P. The second press die 23 is formed with a circular recess 231 having a substantially rectangular cross-sectional shape at the center of the bottom surface. The second cylindrical portion 15 of the cylindrical battery outer can 10 is pressed to the bottom surface of the circular concave portion 231 of the second press die 23 to be strongly pressure-molded in a state of being bent at a substantially right angle as shown in the drawing. . A portion of the second cylindrical portion 15 bent at a substantially right angle is a second peripheral wall 17.

FIG. 5 is a side cross-sectional view illustrating the pressing process.
Subsequently, the cylindrical battery outer can 10 after the second press working is attached to the crimping split mold 24, the crimp receiving stripper 25, and the crimp receiving mold 26. The crimping split mold 24 is a substantially annular split mold having an inner diameter substantially equal to the outer diameter of the cylindrical battery outer can 10, and its inner peripheral surface is in contact with the side surface of the cylindrical battery outer can 10 as shown in the figure. . The crimp receiving stripper 25 is a substantially disk-shaped member, and supports the cylindrical battery outer can 10 in contact with the bottom surface of the cylindrical battery outer can 10. The crimp receiving die 26 is a substantially disk-shaped member in which a circular concave portion 261 having a substantially trapezoidal cross section is formed, and the inclined surface of the circular concave portion 261 contacts the outer peripheral end of the bottom surface of the cylindrical battery outer can 10.

  From this state, the second cylindrical portion 15 (second peripheral wall 17) of the cylindrical battery outer can 10 is pressed downward P by the bottom surface 271 of the crimping press die 27. The crimping press die 27 is formed with a circular recess 272 in the center of the bottom surface 271 for allowing the sealing body 3 to escape. In the cylindrical battery outer can 10, the first cylindrical portion 14 is compressed while the seam 10 a is deformed between the pressure receiving stripper 25 and the pressure receiving mold 26 and the pressure pressing mold 27. Thereby, the cylindrical battery outer can 10 is subjected to high pressure molding so that the total height of the cylindrical battery 20 (the length from the bottom surface of the cylindrical battery outer can 10 to the end face of the sealing body 3) becomes a specified length. Moreover, the space | interval of the 1st surrounding wall 16 and the 2nd surrounding wall 17 becomes narrow because the 1st cylindrical part 14 is compressed, deform | transforming the seam 10a. Thereby, the gasket 4 interposed between the first peripheral wall 16 and the second peripheral wall 17 and the sealing body 3 is appropriately compressed so that the sealed state inside the cylindrical battery outer can 10 can be stably maintained. It will be in the state compressed at the rate (for example, about 30%).

  FIG. 6 is a side sectional view illustrating the outer diameter drawing step.

  Subsequently, the cylindrical battery outer can 10 after the press-pressing process is attached between the drawing receiver 28 and the upper drawing die 29. In the upper diaphragm die 29, a circular recess 292 for allowing the sealing body 3 to escape is formed in the center of the bottom surface 291. The cylindrical battery outer can 10 is supported with its bottom surface in contact with the diaphragm receiving die 28 and fixed with its upper end (second peripheral wall 17) in contact with the bottom surface 291 of the upper diaphragm die 29.

  The substantially annular diaphragm die 30 is formed with a diaphragm protrusion 301 having an inner diameter that is set to an inner diameter that matches the prescribed outer diameter of the cylindrical battery 20. The cylindrical battery outer can 10 has its side face pressed against the diaphragm convex portion 301 of the diaphragm die 30 as the holder 31 holding the diaphragm die 30 moves from the bottom surface side to the upper end side, and the side surface is deformed inward. The outer diameter is reduced. As a result, the cylindrical battery outer can 10 is subjected to high pressure molding so that the outer diameter becomes a specified length.

<Evaluation test of cylindrical battery 20 according to the present invention>
An evaluation test of the cylindrical battery 20 according to the present invention conducted by the inventors will be described.

1. Examples Examples 1 to 7 of the cylindrical battery 20 according to the present invention include a cylindrical battery outer can 10 according to the present invention having a three-stage cylindrical structure with an outer diameter of 14.25 mm and a height of 50.6 mm. It is an alkaline secondary battery manufactured using the manufacturing method described above so that the outer dimensions are φ14.0 mm and the height is 50.2 mm.

  In Examples 1 to 4, the cylindrical battery outer can 10 having a volume of 7.84 cc by setting the wall thickness A of the electrode body housing portion 13 to 0.100 mm was used. In Example 1, the thickness B of the first cylindrical portion 14 is 0.130 mm (about 130% of the thickness A), and the thickness C of the second cylindrical portion 15 is 0.150 mm (about 150% of the thickness A). ). In Example 2, the thickness B of the first cylindrical portion 14 is 0.130 mm (about 130% of the thickness A), and the thickness C of the second cylindrical portion 15 is 0.170 mm (about 170% of the thickness A). It was. In Example 3, the thickness B of the first cylindrical portion 14 is 0.150 mm (about 150% of the thickness A), and the thickness C of the second cylindrical portion 15 is 0.170 mm (about 170% of the thickness A). It was. In Example 4, the thickness B of the first cylindrical portion 14 is 0.150 mm (about 150% of the thickness A), and the thickness C of the second cylindrical portion 15 is 0.200 mm (about 200% of the thickness A). It was.

  Examples 5 to 7 used the cylindrical battery outer can 10 having a volume of 7.89 cc by setting the wall thickness A of the electrode body housing portion 13 to 0.080 mm. In Example 5, the thickness B of the first cylindrical portion 14 is 0.110 mm (about 138% of the thickness A), and the thickness C of the second cylindrical portion 15 is 0.130 mm (about 163% of the thickness A). ). In Example 6, the thickness B of the first cylindrical portion 14 is 0.110 mm (about 138% of the thickness A), and the thickness C of the second cylindrical portion 15 is 0.150 mm (about 188% of the thickness A). It was. In Example 7, the thickness B of the first cylindrical portion 14 is 0.120 mm (about 150% of the thickness A), and the thickness C of the second cylindrical portion 15 is 0.150 mm (about 188% of the thickness A). It was.

2. Comparative Example A comparative example will be described with reference to FIG.
FIG. 7 is a side sectional view illustrating a cylindrical battery outer can 50 (FIG. 7A) and a cylindrical battery 60 (FIG. 7B) of a comparative example.

  The cylindrical battery outer can 50 is a component used for manufacturing the cylindrical battery 60 of the comparative example, and constitutes the outer can 5 in the cylindrical battery 60 of the comparative example. The cylindrical battery outer can 50 is manufactured by processing a metal plate, and has a cylindrical shape having a bottom 11 and an opening 12, that is, a bottomed cylindrical shape. The cylindrical battery outer can 50 includes an electrode body housing portion 13 in which the electrode body 2 serving as a power generation element is housed, and a constant thickness B that is thicker than the wall thickness A of the electrode body housing portion 13 from the electrode body housing portion 13. And a first cylindrical portion 14 continuously provided on the opening 12 side.

  That is, the cylindrical battery outer can 50 of the comparative example and the outer can 5 of the cylindrical battery 60 have a two-stage cylindrical shape in which the thickness increases in two stages from the electrode body housing portion 13 toward the opening 12. This is different from the embodiment of the present invention. Since the other configuration is common to the embodiment of the present invention, the same reference numeral is given and the description is omitted.

  The cylindrical battery 60 of Comparative Examples 1 to 6 is an alkaline secondary battery manufactured using the above-described cylindrical battery outer can 50 having a two-stage cylindrical structure. The outer diameter of the cylindrical battery outer can 50 was φ14.25 mm and the height was 50.6 mm, as in the example. Further, in the same manner as in the example, the outer diameter was manufactured to be φ14.0 mm and the height was 50.2 mm by the manufacturing method described above.

  Comparative Examples 1 to 3 used the cylindrical battery outer can 50 having a volume of 7.84 cc as in Examples 1 to 4 by setting the wall thickness A of the electrode body housing portion 13 to 0.100 mm. In Comparative Example 1, the thickness B of the first cylindrical portion 14 was set to 0.130 mm (about 130% of the thickness A). In Comparative Example 2, the thickness B of the first cylindrical portion 14 was set to 0.150 mm (about 150% of the thickness A). In Comparative Example 3, the thickness B of the first cylindrical portion 14 was set to 0.160 mm (about 160% of the thickness A).

  In Comparative Examples 4 to 6, the cylindrical battery outer can 50 having a volume of 7.89 cc as in Examples 5 to 7 was used by setting the wall thickness A of the electrode body housing portion 13 to 0.080 mm. In Comparative Example 4, the thickness B of the first cylindrical portion 14 was 0.100 mm (about 125% of the thickness A). In Comparative Example 5, the thickness B of the first cylindrical portion 14 was set to 0.120 mm (about 150% of the thickness A). In Comparative Example 6, the thickness B of the first cylindrical portion 14 was set to 0.130 mm (about 163% of the thickness A).

  In addition, the cylindrical battery outer can 50 having a two-stage cylindrical structure in which the thickness B of the first cylindrical portion 14 is 170% or more of the thickness A of the electrode body accommodating portion 13 is manufactured because the difference in thickness is too large. I couldn't.

3. Test Method The appearance of each of the cylindrical batteries 20 of Examples 1 to 7 and the cylindrical batteries 60 of Comparative Examples 1 to 6 was visually evaluated. Moreover, the sealing strength was measured about each of the cylindrical battery 20 of Examples 1-7 and the cylindrical battery 60 of Comparative Examples 1-6. The sealing strength is measured by making a hole in the outer can 1 of the cylindrical battery 20 and the outer can 5 of the cylindrical battery 60 and filling the interior with nitrogen gas at a rate of 0.05 MPa / sec. The filling pressure of nitrogen gas at the time when gas leakage occurred was taken as the sealing strength.

上記の表１に示した試験結果を参照しながら以下説明する。 4). Test results and evaluation

This will be described below with reference to the test results shown in Table 1 above.

  First, Comparative Examples 1 to 3 and Examples 1 to 4 in which the wall thickness A of the electrode body housing part 13 was 0.100 mm and the volume of the cylindrical battery outer can was 7.84 cc were evaluated.

  The sealing strength of Comparative Example 1 was 4.6 MPa, and the sealing strength of Comparative Example 2 was 5.6 MPa. Both the outer cans 5 had no dents and the appearance was good. In Comparative Example 3 in which the thickness B of the first cylindrical portion 14 was increased, a sealing strength of 6.1 MPa higher than those of Comparative Examples 1 and 2 was obtained. However, in Comparative Example 3, the difference between the wall thickness A of the electrode body housing portion 13 and the wall thickness B of the first cylindrical portion 14 is too large, and a dent is generated on the side surface of the outer can 5 in the battery manufacturing process. Therefore, the appearance was evaluated as inappropriate.

  In contrast, in Examples 1 to 4, sealing strengths of 5.6 to 7.8 MPa exceeding those of Comparative Examples 1 and 2 were obtained. In particular, in Examples 2 to 4, a sealing strength of 6.7 to 7.8 MPa exceeding the sealing strength of 6.1 MPa of Comparative Example 3, which was evaluated as inappropriate in appearance evaluation, was obtained. In all of Examples 1 to 4, no dents were produced on the side surfaces in the battery manufacturing process, and the appearance evaluations were all good.

  Next, Comparative Examples 4 to 6 and Examples 5 to 7 in which the wall thickness A of the electrode body housing portion 13 was made thinner, 0.080 mm, and the volume of the cylindrical battery outer can was increased to 7.89 cc were compared. And evaluated.

  The sealing strength of Comparative Example 4 is 3.1 MPa, and the sealing strength of Comparative Example 5 is 3.7 MPa. Both the sealing strengths are lower than those of Comparative Examples 1 to 3 because the thickness B of the first cylindrical portion 14 is reduced. However, in any case, the outer can 5 did not have a dent in the battery manufacturing process, and the appearance was good. In Comparative Example 6 in which the thickness B of the first cylindrical portion 14 was increased, a sealing strength of 4.6 MPa higher than those of Comparative Examples 4 and 5 was obtained. However, in Comparative Example 6, the difference between the wall thickness A of the electrode body housing portion 13 and the wall thickness B of the first cylindrical portion 14 is too large, and a dent is generated on the side surface of the outer can 5 in the battery manufacturing process. Therefore, the appearance was evaluated as inappropriate.

  In contrast, in Examples 5 to 7, sealing strengths of 4.6 to 5.6 MPa exceeding Comparative Examples 4 and 5 were obtained. In particular, in Examples 6 and 7, a sealing strength of 5.6 MPa was obtained, which exceeded the sealing strength of 4.6 MPa of Comparative Example 6 that was evaluated as inappropriate in appearance evaluation. In all of Examples 5 to 7, no dent was formed on the side surface in the battery production process, and the appearance evaluation was good.

  As a conclusion, in the cylindrical battery 60 of the comparative example using the cylindrical battery outer can 50 having a two-stage cylindrical structure, the thickness of the second peripheral wall 17 that caulks the sealing body 3 (the thickness of the first cylindrical portion 14). The thickness B) was limited to about 150% of the wall thickness A of the electrode body housing portion 13. On the other hand, in the embodiment of the cylindrical battery 20 using the cylindrical battery outer can 10 of the three-stage cylindrical structure according to the present invention, the thickness (second cylindrical portion) of the second peripheral wall 17 for caulking the sealing body 3. It was possible to increase the thickness C) of 15 to about 200% of the thickness A of the electrode body accommodating portion 13.

  As described above, the outer can 1 (cylindrical battery outer can 10) of the cylindrical battery 20 according to the present invention increases in thickness in three stages from the electrode body housing portion 13 toward the opening 12. Even if the difference between the thickness A of the electrode body accommodating portion 13 and the thickness of the sealing portion (thickness C of the second cylindrical portion 15) is increased, the rigidity caused by the difference in thickness is obtained. Can be made smaller than before. Therefore, it is possible to reduce the possibility that the outer can 1 is deformed due to the rigidity imbalance in press working or drawing work when manufacturing the cylindrical battery 20. Thereby, the cylindrical battery 20 according to the present invention realizes a further increase in the capacity by increasing the volume of the outer can 1 as compared with the conventional one while maintaining the strength of the sealing portion by the sealing body 3 at a level at which liquid leakage does not occur. can do.

  Further, in the outer can 1 (cylindrical battery outer can 10) of the cylindrical battery 20 according to the present invention, the thickness B of the first cylindrical portion 14 is constant, and the thickness C of the second cylindrical portion 15 is also constant. is there. Therefore, since the inner peripheral surfaces of the first cylindrical portion 14 and the second cylindrical portion 15 and the sealing body 3 face each other substantially in parallel, the inner peripheral surfaces and the sealing surfaces of the first cylindrical portion 14 and the second cylindrical portion 15 are sealed. It is possible to easily make the gasket 4 interposed between the body 3 and the body 3 compressed into a substantially uniform state. Therefore, the cylindrical battery 20 according to the present invention can greatly reduce the possibility of liquid leakage from the sealing portion due to a decrease in sealing strength due to the non-uniform compression state of the gasket 4.

Thus, according to the present invention, in the cylindrical battery 20, it is possible to realize a further increase in capacity while maintaining the strength of the sealing portion by the sealing body 3 at a level at which liquid leakage does not occur.
Note that the present invention is not particularly limited to the above-described embodiments, and it goes without saying that various modifications are possible within the scope of the invention described in the claims.

DESCRIPTION OF SYMBOLS 1 Exterior can 2 Electrode body 3 Sealing body 4 Gasket 10 Cylindrical battery exterior can 13 Electrode body accommodating part 14 1st cylindrical part 15 2nd cylindrical part 16 1st surrounding wall 17 2nd surrounding wall

Claims (3)

A bottomed cylindrical outer can,
An electrode body as a power generation element;
A sealing body for sealing the opening of the outer can;
A gasket interposed between the outer can and the sealing body,
The outer can is connected to an electrode body housing portion in which the electrode body is housed and a constant thickness larger than a thickness of the electrode body housing portion on the opening side from the electrode body housing portion. A first cylindrical wall supporting the first cylindrical portion formed inside by press working, and a constant thickness that is thicker than a thickness of the first cylindrical portion, are provided continuously to the opening side from the first cylindrical portion, A cylindrical battery, comprising: a second cylindrical portion having a second peripheral wall sandwiched between the first peripheral wall and a second cylindrical portion formed inside by pressing. A cylindrical battery outer can having a bottomed cylindrical shape,
An electrode body housing portion in which an electrode body serving as a power generation element is housed;
A first cylindrical portion continuously provided on the opening side from the electrode body housing portion with a constant thickness thicker than the thickness of the electrode body housing portion;
A cylindrical battery outer can comprising: a second cylindrical portion continuously provided on the opening side of the first cylindrical portion with a constant thickness larger than the thickness of the first cylindrical portion.   The cylindrical battery outer can according to claim 2, wherein the inner diameter of the cylindrical battery outer can is constant from the bottom to the opening.

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