JP6160185B2 - Rectangular container, method for manufacturing rectangular container, and method for manufacturing secondary battery - Google Patents

Description

  The present invention relates to a rectangular container, a method for manufacturing a rectangular container, and a method for manufacturing a secondary battery, and more particularly to a rectangular container used for a rectangular secondary battery, a method for manufacturing a rectangular container, and a method for manufacturing a rectangular secondary battery.

  2. Description of the Related Art In recent years, secondary batteries (storage batteries) for power storage systems such as solar power generation and electric vehicles have become widespread in response to increasing demand. In these secondary batteries, a rectangular shape is often adopted from the viewpoint of applicability to each system or product and storage capacity (hereinafter referred to as a rectangular battery). This rectangular battery is composed of, for example, a metal outer can (rectangular container) and a sealing lid, and employs a structure in which the sealing lid is welded and sealed to the opening of the outer can.

  And in the rectangular battery composed of a metal outer can and a sealing lid, as a method of positioning the sealing lid at the time of welding, a method of providing a stepped portion for placing the end of the sealing lid on the inner peripheral surface of the opening of the outer can Has been proposed. For example, Patent Document 1 discloses a rectangular battery outer can in which a step portion is provided at the corner of the opening end by drawing, and Patent Document 2 expands the opening end formed by deep drawing. A closed prismatic battery container in which a mouthed metal square container is attached to an ironing die and subjected to ironing with an ironing punch to form a stepped portion, and a method for manufacturing the same are disclosed. Furthermore, Patent Document 3 discloses a rectangular outer container in which positioning protrusions are formed on the inner side of the container by extrusion or embossing in order to prevent the lid from falling into the outer container, and a manufacturing method thereof.

JP-A-9-265966 JP-A-9-293487 Japanese Patent Laid-Open No. 11-219688

  However, in the method of providing a stepped portion for placing the end portion of the sealing lid on the inner peripheral surface of the opening of the outer can, Patent Document 1 performs drawing with the shape of the corner of the punch as a protruding shape, and the opening of the outer can On the other hand, in Patent Document 2, a metal rectangular container with an open end formed by deep drawing is attached to an ironing die and subjected to ironing with an ironing punch to form a stepped part. Is formed. For this reason, since the thickness changes at the stepped portion or at the stepped portion, the stepped portion serves as a base point, and cracks, breaks, etc. are likely to occur (cylinder) during molding, and productivity is lowered.

  Further, in the method of projecting the protrusions inward by the protrusion processing or the like of Patent Document 3, the positioning space protrudes into the storage space, so that the storage space may be reduced.

  Accordingly, an object of the present invention is to prevent cracking at the time of molding of the stepped portion and improve productivity and reduce the storage space in manufacturing a rectangular container having a stepped portion on which a sealing lid is placed. It is intended to provide a rectangular container that can prevent the above, a method for manufacturing the rectangular container, and a method for manufacturing a secondary battery using the rectangular container.

In order to achieve the above object, the method for producing a rectangular container of the present invention comprises:
In a method for manufacturing a metal rectangular container comprising a stepped portion that is composed of a rectangular cylindrical portion and a bottom portion and places a sealing lid on the inner periphery of the opening of the rectangular cylindrical portion,
Forming a stepped portion inside the opening by projecting at least part of the vicinity of the rectangular container opening to the outside; and
Removing the projecting portion projecting outward in the vicinity of the opening on the outer surface of the rectangular container by the above-described process by relative movement of the removing tool disposed on the outer side of the rectangular container and the rectangular container;
It is characterized by including.

The manufacturing method of the rectangular container of this invention can also be comprised as follows.
1. The protrusion is removed by relatively moving the removal tool in a state where the opening end of the opening is supported by an inner support that supports the inside of the stepped portion.
2. The step portion is formed by semi-shearing or bead forming.
3. A cross-sectional shape of the rectangular cylindrical portion is rectangular, and the stepped portion is formed in a short side region facing the opening.
4). The rectangular container before forming the protruding portion is formed by drawing or drawing-ironing.

  In order to achieve the above object, a method for manufacturing a secondary battery according to the present invention includes a sealing lid placed on a step portion of a rectangular container obtained by the method for manufacturing a rectangular container, The outer peripheral end portion and the upper peripheral portion of the rectangular cylindrical portion of the rectangular container are welded.

In order to achieve the above object, the rectangular container of the present invention comprises:
A metal rectangular container comprising a stepped portion for placing a sealing lid on the inner periphery of the opening of the rectangular tubular portion, comprising a rectangular tubular portion and a bottom,
The stepped portion has a sheared surface by semi-shear processing or a stepped surface by bead forming processing, and is provided in each of the short side regions opposed to the opening having a rectangular cross section,
A removal processing region in which a protruding portion protruding outward is removed and an outer shape without a protrusion is formed in at least a region outside the stepped portion on the outer peripheral surface of the rectangular cylindrical portion, and other than the processing region Is formed by a bottomed cylindrical metal molded body including the bottom portion and the rectangular cylindrical portion having a rectangular cross-sectional shape extending in a cylindrical shape from the metal plate by drawing or drawing-ironing drawing. It has been squeezed, or squeezed - ironing area der is,
The outer peripheral surface of the rectangular cylindrical portion is substantially the same surface as the removal processing region and the drawing or drawing-ironing processing region.
The inner peripheral surface of the rectangular tubular portion is squeezed inner region wherein corresponding to the removing processing area, or aperture - ironing dented than the processing region, characterized in Rukoto.

According to the method for manufacturing a rectangular container of the present invention, the stepped portion is formed while maintaining the thickness of the rectangular cylindrical portion of the rectangular container. Therefore, cracks, breakage, and the like can be effectively prevented in forming the stepped portion.
Further, since the stepped portion is formed to protrude outward, a reduction in the space for loading the rectangular container is prevented.
Further, by removing the protruding portion protruding outward in a step different from the step portion forming, an outer shape without a bulge can be stably formed with high accuracy.

  In addition, according to the method for manufacturing a rectangular container of the present invention, the protrusion is accurately removed by relatively moving the removal tool while the opening end of the opening is supported by the inner support that supports the inside of the stepped portion. can do.

  Moreover, according to the manufacturing method of the square container of this invention, the level | step-difference part which mounts a sealing lid can be accurately formed by forming a level | step-difference part by a semi-shear process or a bead molding process.

In addition, according to the method for manufacturing a rectangular container of the present invention, when the rectangular cylindrical section has a rectangular cross-sectional shape, the portion where the stepped portion is formed is the short side region facing the opening, thereby Since molding is easy and molding accuracy is improved, an accurate sealing lid positioning shape with stable dimensions can be provided. In addition, by forming the projecting portion at the short side region and reducing the amount of deformation of the outer shape, it is possible to reduce the applicability to each system and product and the effect on accommodation.

  Furthermore, the formation of the protruding portion is performed in a process different from the drawing or drawing-ironing process, so that the production line is not stopped due to the crack or breakage of the protruding portion, which is likely to occur in the drawing or drawing-ironing process. , Productivity can be improved.

  In addition, according to the method for manufacturing a rectangular secondary battery of the present invention, since the sealing lid is placed on the stepped portion protruding outward and welding is performed, cracks, breakage, and reduction of the storage space in the stepped portion are prevented. Thus, it is possible to obtain a prismatic secondary battery, and it is possible to easily perform welding from above.

  In addition, according to the rectangular container of the present invention, a rectangular container with high dimensional accuracy and high productivity can be obtained in the configuration in which the stepped portion for placing the sealing lid is provided on the inner periphery of the opening of the rectangular cylindrical portion. Can do. That is, by providing the stepped portion with a sheared surface by semi-shearing or a stepped surface by bead forming, it is possible to provide a sealing lid positioning shape with stable dimensions. In addition, the outer peripheral surface of the rectangular cylindrical portion includes a removal processing region and a drawing or drawing-ironing processing region, so that a highly accurate outer shape can be provided.

Schematic diagram of a prismatic secondary battery using an outer can obtained by the manufacturing method of the present invention The schematic diagram of the manufacturing method of the armored can and the square secondary battery in Embodiment 1 of this invention The model enlarged view of the protrusion formation process in the manufacturing method of the armored can in Embodiment 1 of this invention, and a trimming process The schematic diagram of the welding process in the manufacturing method of the square secondary battery of this invention The schematic diagram of the manufacturing method of the armored can and the square secondary battery in Embodiment 2 of this invention Schematic enlarged view of a protrusion forming step and a trimming step in the method for manufacturing an outer can according to Embodiment 2 of the present invention

  Embodiments for carrying out the present invention will be described below with reference to the drawings. In addition, the material of the structure in this embodiment, a shape, those relative arrangement | positioning, etc. can be changed suitably, and the range of this invention is not limited to the following this embodiment.

(Embodiment 1)
With reference to FIGS. 1-4, Embodiment 1 of the manufacturing method of the armored can (rectangular container) of this invention and a square secondary battery is demonstrated.

<Schematic configuration of prismatic secondary battery>
FIG. 1 is a schematic diagram of a rectangular secondary battery using an outer can obtained by the manufacturing method of the present invention. The square secondary battery 1 includes an outer can 2 having an opening 22 and the opening 22. And a sealing lid 3 for closing.

  The outer can 2 and the sealing lid 3 constituting the rectangular secondary battery 1 are made of, for example, a metal plate such as an aluminum alloy, and various power generation elements (for example, electrodes, separators, etc.) constituting the battery are accommodated therein. The In addition, a metal plate is not specifically limited, For example, other metal materials, such as SPCE (cold rolled steel plate), SUS (stainless steel), an iron nickel steel plate, may be sufficient.

The outer can 2 has a bottomed cylindrical structure in which a rectangular cylindrical portion 20 and a bottom portion 21 are integrally formed. A step portion 23 for placing the end portion of the sealing lid 3 is provided at the inner peripheral end of the opening portion 22 of the rectangular tubular portion 20. The step portions 23 are formed in the short side regions of the substantially rectangular opening 22 facing each other so as to protrude outward. The rectangular secondary battery 1 is formed by closing the opening 22 of the outer can 2 with the sealing lid 3.

  In the present embodiment, the prismatic secondary battery 1 (exterior can 2) is configured in a substantially rectangular parallelepiped shape in which each surface is formed of a rectangle having a long side and a short side. For example, each surface is a square. The substantially rectangular parallelepiped shape comprised by these may be sufficient.

<Manufacturing method of outer can and prismatic secondary battery>
With reference to FIGS. 2-4, the manufacturing method of the armored can 2 and the square secondary battery 1 which concern on this embodiment is demonstrated. This manufacturing method is roughly composed of (1) a metal molded body manufacturing step, (2) a stepped portion forming step, (3) a protruding portion removing step, and (4) a welding step. The manufacturing method of the outer can 2 according to the present invention is mainly configured by (2) a stepped portion forming step and (3) a protruding portion removing step.

(1) Metal molded body manufacturing process This process is not shown in the figure, but a rectangular cylinder having a rectangular cross section extending from the metal plate to the bottom 201 and from the bottom 201 by a conventionally known drawing or drawing-ironing process. A bottomed cylindrical metal molded body 200 having a portion 202 is created. Then, as shown in FIG. 2A, the rectangular cylindrical portion 202 of the metal molded body 200 is cut by, for example, a trimming cutter, and the portion 202a left as the rectangular cylindrical portion 20 of the outer can 2 is removed by trimming. It is separated into unnecessary portions 202b.

(2) Stepped portion forming step In this step, as shown in FIG. 2B, a stepped portion 203 is formed in the opening of the rectangular tubular portion 202a. FIG. 3A shows the respective states before the stepped portion is formed, and FIG. 3B shows the respective states after the stepped portion is formed. The stepped portion 203 is formed using an outer tool 301 and an inner tool 302 as shown in FIGS. The outer tool 301 and the inner tool 302 are alternately arranged at different heights with the square cylindrical portion 202a interposed therebetween. By moving the outer tool 301 and the inner tool 302 relative to each other in the horizontal direction, the opening portion of the rectangular tubular portion 202a is partially semi-sheared so that the opening end side of the opening portion of the rectangular tubular portion 202a is displaced outward. Let As a result, a stepped portion 203 is formed on the inner side surface of the opening of the rectangular tubular portion 202 a, and this finally becomes the stepped portion 23 of the outer can 2. In addition, a protruding portion 204 that protrudes outward is formed on the outer surface of the opening of the rectangular tubular portion 202a. In this embodiment, the side wall thickness is 0.6 to 1.0 mm, the pushing amount of the outer tool 301 and the inner tool 302 is 0.2 mm, and the protruding height of the protruding portion 204 is 0.2 mm. Thus, by forming the stepped portion 203 by half-shear processing, the stepped portion 23 on which the sealing lid 3 is placed can be processed and formed with high accuracy.

(3) Protrusion part removal process This process removes the protrusion part 204 formed by the level | step-difference part formation process mentioned above, as shown in FIG.2 (C). As shown in FIG. 3C, the metal molded body 200 is fixed to the inner support 303 so that the open end 204c of the square cylindrical portion 202a abuts on the open end support portion 303c, and the cutting tool 304 is square cylindrical. The unit 202a is moved along the outer surface on the main body side. The projecting portion 204 is removed from the rectangular cylindrical portion 202a by moving the cutting tool 304 relative to the metal molded body 200 by providing a predetermined clearance C with respect to the outer surface on the main body side of the rectangular cylindrical portion 202a. . Thus, by cutting and removing the protruding portion 204 by cutting, it is possible to finish the outer shape with high dimensional accuracy. Thereby, as shown in FIG. 2C, the outer can 2 having the stepped portion 23 inside the opening 22 is completed. Therefore, the outer peripheral surface of the rectangular cylindrical portion 20 of the outer can 2 according to the present embodiment includes a cutting region in the vicinity of the opening 22 and a restriction on the main body side (region excluding the vicinity of the opening 22) or a drawing-ironing. It consists of a single surface consisting of a machining area. In addition, as a means to remove a protrusion part, it is not limited to the illustrated cutting process, In addition, well-known methods, such as a grinding process and electrical discharge machining, are employable.

(4) Welding process As shown in FIGS. 2 (D) and 4, this process is performed by placing a predetermined lid in the outer can 2 formed by the above-described removing process, and then attaching the sealing lid 3 to the outer can. The outer peripheral end portion of the sealing lid 3 and the upper peripheral portion of the rectangular tubular portion 20 of the outer can 2 are welded by being fitted into the two opening portions 22 and welded. Thereby, the sealing lid 3 is welded to the outer can 2, and the rectangular secondary battery 1 is completed. Examples of the welding means include electric resistance welding, soldering, arc welding and the like in addition to laser welding.

(Embodiment 2)
With reference to FIG.5 and FIG.6, Embodiment 2 of the manufacturing method of the armored can and the square secondary battery of this invention is demonstrated. In the said Embodiment 1, although the level | step-difference part 23 was formed by the semi-shear process, the shaping | molding method of the level | step-difference part 23 is not limited to this. In this embodiment, the example which forms the level | step-difference part 23 by bead shaping | molding is shown. Here, only differences from the first embodiment will be mainly described here, and common items are denoted by the same reference numerals and description thereof is omitted. Matters not specifically described here are the same as those in the first embodiment.

<Manufacturing method of outer can and prismatic secondary battery>
With reference to FIG. 5, FIG. 6, the manufacturing method of the armored can 2 and the square secondary battery 1 which concern on this embodiment is demonstrated. The manufacturing method is roughly as follows: (1) Metal plate drawing or drawing-ironing process (not shown), (2) Projection forming process, (3) Trimming process, (4) Projection removing process, (5 ) Consists of welding process. The manufacturing method of the outer can 2 in the present invention is mainly configured by (2) a protruding portion forming step to (4) a protruding portion removing step.

(1) Metal molded body manufacturing process As in Embodiment 1, this process is a square having a rectangular cross section extending from a metal plate material to the bottom 201 and from the bottom 201 by a conventionally known drawing or drawing-ironing process. A bottomed cylindrical metal molded body provided with the cylindrical portion 202 is created. At this time, there is no need to form a protrusion that remains as a stepped portion, which will be described later, into the rectangular tubular portion 202, and it can be easily formed by applying to a conventional drawing or drawing-ironing process.

(2) Protrusion part formation process This process is performed using the protrusion part formation apparatus 400 shown to FIG. 5 (A), (B), FIG. 6 (A), (B). 5 (A) and 6 (A) are before the second molding tool is pushed into the first molding tool (before the protrusion is formed), and FIGS. 5 (B) and 6 (B) are the second molding. The respective states after the tool is pushed into the first forming tool (after the protrusion is formed) are shown.

  The protrusion forming device 400 includes a die 401 of a first forming tool and a punch 402 of a second forming tool. The punch 402 has an inclined surface at the rear end, and is inclined to slide with the inclined surface. The pusher 403 having a surface is moved in the horizontal direction by moving up and down.

  As shown in FIGS. 5A and 6A, the die 401 is brought into contact with the outer peripheral surface of the short side region of the rectangular cylindrical portion 202 of the metal molded body 200, and the punch 402 is brought into contact with the inner peripheral surface. Let The die 401 is brought into contact with the outer peripheral surface of the rectangular tubular portion 202 at a predetermined height position from the bottom portion 201. Each die 401 is configured to have a pair of contact portions, and the first contact portion 401a and the second contact portion 401b are arranged with a predetermined gap in the height direction (vertical direction). The The punch 402 is disposed at a predetermined height between the first contact portion 401a and the second contact portion 401b.

Then, as shown in FIGS. 5B and 6B, when the pusher 403 descends, the punches 402 on both sides move toward the outside, and the first contact portion 401a and the first 2 Move so as to enter the gap between the contact portions 401b. As a result, a part of the rectangular tubular portion 202 of the metal molded body 200 is pushed between the first contact portion 401a and the second contact portion 401b and outwards to a predetermined height position of the rectangular tubular portion 202. A protruding portion 204 that protrudes is formed. As described above, the protruding portion 204 of the rectangular tubular portion 202 that remains as the stepped portion is easily formed by controlling the gap in the height direction of the protruding portion by the gap of the die 401.

  The distance a (see FIG. 6A) between the first contact portion 401a and the second contact portion 401b of the die 401 and the pushing amount (movement amount) of the punch 402 are the same as those in the rectangular cylindrical portion 202 when the protrusion is formed. The protrusion 204 is appropriately set within a range in which no crack is generated (for example, 50 to 300% with respect to the side wall thickness). In this embodiment, the side wall thickness is 0.6 mm, and the protruding height of the protruding portion 204 is 0.5 mm. Further, the pushing amount of the punch 402 can be easily adjusted by adjusting the inclination angle of the sliding surface and the moving amount of the pusher 403.

(3) Trimming Step In this step, as shown in FIGS. 5C, 6C, and 6D, trimming is performed at the protruding portion 204 of the rectangular cylindrical portion 202 formed by the above-described protruding portion forming step. It carries out and makes the metal molded object 200 the same state as the state before the protrusion part removal process of the said Embodiment 1. FIG. Specifically, the rectangular cylindrical portion 202 of the metal molded body 200 is separated into, for example, a portion 202a that is left as the rectangular cylindrical portion 20 of the outer can 2 by cutting with a trimming cutter and an unnecessary portion 202b that is removed by trimming. To do. The height at which the rectangular cylindrical portion 202 is separated is set in consideration of the desired height of the joint surface with the end surface of the sealing lid 3 at the step portion 23. The specific height is appropriately set according to the thickness (end face width) of the sealing lid 3, for example.

(4) Protrusion removal process This process is the same as the protrusion removal process (FIG. 3C) in the first embodiment. By this step, the outer can 2 including the step portion 23 is formed from the metal formed body 200 as shown in FIG. In addition, as a means to remove a protrusion part, it is not limited to the illustrated cutting process, In addition, well-known methods, such as a grinding process and electrical discharge machining, are employable.

(5) Welding Step This step is the same as the welding step (FIG. 4) in the first embodiment. Through this step, the sealing lid 3 is welded to the outer can 2 to complete the rectangular secondary battery 1 (FIG. 2D). Examples of the welding means include electric resistance welding, soldering, arc welding and the like in addition to laser welding.

  In the embodiment of the present invention, the place where the stepped portion 23 is provided is not limited to the entire short side region of the opening 22 of the rectangular tubular portion, and the sealing lid 3 is supported when the sealing lid 3 is welded. For example, a configuration in which the stepped portion 23 is partially formed in the short side region may be used. Moreover, the structure formed in the whole long side area | region or may be sufficient.

1 prismatic secondary battery 2 outer can (square container)
20 square cylindrical part 21 bottom part 22 opening part 23 step part 3 sealing lid

Claims (7)

In the method for manufacturing a metal outer can comprising a step-shaped portion that includes a rectangular tubular portion and a bottom portion and places a sealing lid on the inner periphery of the opening of the rectangular tubular portion,
Forming a stepped portion inside the opening by projecting at least part of the vicinity of the rectangular container opening to the outside; and
Removing the projecting portion projecting outward in the vicinity of the opening on the outer surface of the rectangular container by the above-described process by relative movement of the removing tool disposed on the outer side of the rectangular container and the rectangular container;
The manufacturing method of the square container characterized by including.   2. The square according to claim 1, wherein the protrusion is removed by relatively moving the removal tool in a state where the opening end of the opening is supported by an inner support that supports the inside of the stepped portion. Container manufacturing method.   The method for manufacturing a rectangular container according to claim 1 or 2, wherein the stepped portion is formed by a semi-shear process or a bead molding process.   4. The rectangular container according to claim 1, wherein the rectangular cylindrical portion has a rectangular cross-sectional shape, and the stepped portion is formed in a short-side region opposed to the opening. 5. Manufacturing method.   The method for manufacturing a rectangular container according to any one of claims 1 to 4, wherein the rectangular container before forming the protruding portion is formed by drawing or drawing-ironing. A sealing lid is placed on the step portion of the rectangular container obtained by the method for manufacturing a rectangular container according to any one of claims 1 to 5, and an outer peripheral end of the sealing lid and a rectangular shape of the rectangular container. A method for manufacturing a prismatic secondary battery, comprising welding a peripheral portion at an upper end of a cylindrical portion. A metal rectangular container comprising a stepped portion for placing a sealing lid on the inner periphery of the opening of the rectangular tubular portion, comprising a rectangular tubular portion and a bottom,
The stepped portion has a sheared surface by semi-shear processing or a stepped surface by bead forming processing, and is provided in each of the short side regions opposed to the opening having a rectangular cross section,
A removal processing region in which a protruding portion protruding outward is removed and an outer shape without a protrusion is formed in at least a region outside the stepped portion on the outer peripheral surface of the rectangular cylindrical portion, and other than the processing region Is formed by a bottomed cylindrical metal molded body including the bottom portion and the rectangular cylindrical portion having a rectangular cross-sectional shape extending in a cylindrical shape from the metal plate by drawing or drawing-ironing drawing. It has been squeezed, or squeezed - ironing area der is,
The outer peripheral surface of the rectangular cylindrical portion is substantially the same surface as the removal processing region and the drawing or drawing-ironing processing region.
The inner peripheral surface of the rectangular tubular portion, the removal processing region within the peripheral region stop the corresponding, or stop - ironing area rectangular container, wherein Rukoto dented than.

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