WO2018061673A1

WO2018061673A1 - Method for producing square can

Info

Publication number: WO2018061673A1
Application number: PCT/JP2017/032107
Authority: WO
Inventors: 庸介小川; 健太郎鵜飼; 圭大堀; 達矢長船; 高則中川
Original assignee: 東洋製罐株式会社
Priority date: 2016-09-27
Filing date: 2017-09-06
Publication date: 2018-04-05
Also published as: JP6776768B2; JP2018051575A

Abstract

The present invention provides a method for producing a square can, said method making it possible to further reduce the radius of curvature of four corners of the bottom of the square can. Provided is a method for producing a bottomed square can, wherein the method is characterized by including: a step for performing a coining process on a portion of a metal sheet that corresponds to a side wall of a final molded article and at least part of a portion of the metal sheet that has undergone drawing and ironing; and a step for performing a drawing and ironing process on a blank that has undergone the coining process.

Description

Manufacturing method of square can

The present invention relates to a method for manufacturing a rectangular can including a drawing ironing process.

Metal square cans can be obtained by drawing and ironing a blank. FIG. 14 is a perspective view of the rectangular can obtained as described above. The square can 1000 includes a bottom plate portion 1300 having a substantially quadrangular planar shape, a side wall including a long side of the bottom plate portion 1300 (first side wall 1100), and a side wall including a short side of the bottom plate portion 1300 (second side wall 1200). It has. The four corners of the bottom plate portion 1300 of such a rectangular can become curved surfaces in terms of manufacturing method. That is, the corner 1300X of the bottom plate 1300, the corner 1100X of the first side wall 1100, and the corner 1200X of the second side wall 1200 are all configured by curved lines. Here, for various reasons such as quality and function, it may be required to make the radius of curvature of the curved surfaces at the four corners as small as possible. That is, it may be required to make the curvature radius R of the corner portion 1300X, the corner portion 1100X, and the corner portion 1200X as small as possible. For example, when a rectangular can is used as a case of a lithium ion battery, it is desired that the radius of curvature R is as small as possible from the viewpoints of cooling performance, battery holding performance, handleability, and storage.

However, when the squeezing and ironing process is performed, the stress on the portions corresponding to the four corners of the molded product increases as the radius of curvature R decreases. As a result, cracks and cracks are likely to occur near the four corners.

Japanese Patent No. 4702843 Japanese Patent No. 3579936 JP 2014-231064 A

An object of the present invention is to provide a method of manufacturing a rectangular can that makes it possible to further reduce the radius of curvature at the four corners of the bottom of the rectangular can.

The present invention employs the following means in order to solve the above problems.

That is, the manufacturing method of the rectangular can of the present invention,
A method of manufacturing a bottomed rectangular can,
A step of performing coining on at least a part of a portion corresponding to the side wall of the final molded product and a portion subjected to drawing and ironing on the metal plate,
A step of drawing and ironing the blank subjected to the coining process;
It is characterized by including.

According to the present invention, coining is performed in advance on at least a part of the portion of the blank to be drawn and ironed. Thereby, since the thickness of the metal plate is reduced in advance, the amount (ratio) of reducing the thickness of the metal plate by drawing ironing can be reduced. Therefore, it is possible to reduce the stress on the portions corresponding to the four corners of the bottom plate portion of the square can, and to suppress the occurrence of cracks and cracks in the vicinity of the four corners. Therefore, the radius of curvature at the four corners of the bottom plate portion of the rectangular can can be further reduced. This also makes it possible to reduce the curvature radius of the bottom plate portion connected to the four corners of the bottom plate portion of the rectangular can and the corner portion of the side wall.

Here, the coining process may be performed on at least a part of the periphery of the planned bottom portion serving as a bottom plate portion of the rectangular can.

This makes it possible to effectively reduce the stress on the portions corresponding to the four corners of the bottom plate portion of the square can.

The planar shape of the bottom plate portion of the square can is a substantially rectangular shape,
The coining process may be performed along a pair of long sides in a planned bottom portion that is a substantially rectangular bottom plate portion.

In addition, the planar shape of the area where the coining process is performed is
It is a shape having at least a straight part parallel to the long side and a hatched part provided so as to be away from the planned bottom part from an end of the straight part,
The hatched portion may be provided in the final molded product so as to be substantially parallel to a boundary line between a side wall including the long side of the bottom plate portion and a side wall including the short side of the bottom plate portion.

Further, the planar shape of the bottom plate portion of the square can is a substantially rectangular shape,
It is also preferable to perform the coining process along a pair of short sides in the planned bottom portion which becomes a substantially rectangular bottom plate portion.

In addition, the planar shape of the area where the coining process is performed is
It is a shape having at least a straight line portion parallel to the short side, and a hatched portion provided so as to be away from the planned bottom portion from an end portion of the straight line portion,
The hatched portion may be provided in the final molded product so as to be substantially parallel to a boundary line between a side wall including the long side of the bottom plate portion and a side wall including the short side of the bottom plate portion.

Further, the planar shape of the bottom plate portion of the square can is a substantially rectangular shape,
It is also preferable to apply the coining process to four regions in the vicinity of each of the four corners where the long side and the short side intersect in the planned bottom portion which is a substantially rectangular bottom plate portion.

Furthermore, the planar shape of the bottom plate portion of the square can is a substantially rectangular shape,
The coining process may be performed so as to surround the periphery of the planned bottom portion which becomes a substantially rectangular bottom plate portion.

Further, the coining process may be performed on a part of a planned bottom portion which becomes a bottom plate portion of the square can.

When performing the coining process, it is preferable to hold the periphery of the area to be coined.

By doing so, it is possible to suppress the increase in the thickness around the area where the coining process is performed due to the coining process.

Note that the above configurations can be combined as much as possible.

As described above, according to the present invention, the curvature radii at the four corners of the bottom of the rectangular can can be further reduced.

It is coining process explanatory drawing which concerns on embodiment of this invention. It is coining process explanatory drawing which concerns on embodiment of this invention. It is a top view of the blank in which the coining process which concerns on embodiment of this invention was given. It is drawing drawing process explanatory drawing which concerns on embodiment of this invention. It is drawing drawing process explanatory drawing which concerns on embodiment of this invention. FIG. 3 is a perspective view of a first intermediate molded product that has been subjected to drawing ironing according to an embodiment of the present invention. It is drawing drawing process explanatory drawing with respect to the 1st intermediate molded product which concerns on embodiment of this invention. It is drawing drawing process explanatory drawing with respect to the 1st intermediate molded product which concerns on embodiment of this invention. FIG. 6 is a perspective view of a second intermediate molded product that has been subjected to drawing ironing according to an embodiment of the present invention. FIG. 3 is a perspective view of a final molded product that has been subjected to drawing ironing according to an embodiment of the present invention. It is a perspective view of the final product concerning the embodiment of the present invention. It is a top view of the modification 1 of the blank in which the coining process which concerns on embodiment of this invention was given. It is a top view of the modification 2 of the blank in which the coining process which concerns on embodiment of this invention was given. It is a perspective view of a general square can.

DETAILED DESCRIPTION Exemplary embodiments for carrying out the present invention will be described in detail below based on the exemplary embodiments with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. .

(Embodiment)
A method for manufacturing a rectangular can according to an embodiment of the present invention will be described in the order of manufacturing steps with reference to FIGS.

<Coining process>
In particular, the coining process will be described with reference to FIGS. However, description will be made with reference to the perspective view of the final molded product 50 shown in FIG. 10 and the perspective view of the final product (rectangular can 60) shown in FIG. 1 and 2 are explanatory diagrams of coining processing steps according to the embodiment of the present invention. 1 and 2 are schematic configuration cross-sectional views showing the main part of a processing apparatus that performs coining, FIG. 1 shows a state before processing, and FIG. 2 shows a state immediately after processing. FIG. 3 is a plan view of a blank subjected to coining according to an embodiment of the present invention.

The coining processing apparatus according to the present embodiment includes a pair of coining punches 100, a coining die 200, and a metal plate pressing member 300. The metal plate pressing member 300 is provided with a pair of through holes 310 through which the coining punch 100 passes. A coining process is performed on the metal plate 10 by the coining apparatus configured as described above.

The metal plate 10 according to the present embodiment is made of a metal such as aluminum. Moreover, the metal plate 10 which concerns on this embodiment is the blank previously cut by the fixed shape. The metal plate 10 is installed on the die 200. The metal plate 10 is pressed by the coining punch 100. Thereby, a part of the metal plate 10 is compressed by the coining punch 100 and the die 200 to be plastically deformed, and the thin portion 21 is formed. The planar shape of the thin portion 21 is the same as the shape of the front end surface of the coining punch 100. Further, when performing the coining process, since the periphery of the area to be subjected to the coining process is pressed by the metal plate pressing member 300, the metal plate 10 is prevented from being warped or distorted.

As shown in FIG. 3, a pair of thin portions 21 are formed on the blank 20 that has been subjected to coining. That is, if the thickness of the metal plate 10 before being processed is t1, and the thickness t11 of the thin portion 21 is t11 <t1. Note that the region where the coining process is performed corresponds to the thin portion 21. Moreover, the part shown with a dotted line in FIG. 3 is the bottom plan part 22 used as the bottom plate part in the square can and final molded product which are final products.

Coining is performed on at least a part of the periphery of the planned bottom portion 22. In the present embodiment, the planar shape of the bottom plate portion 53 (see FIG. 11) of the rectangular can 60 (which is the same as the planar shape of the planned bottom portion 22) is a substantially rectangular shape. More specifically, it is a shape in which four corners of a rectangle are configured by curved lines having a small curvature radius. In the present embodiment, coining is performed along the pair of long sides in the planned bottom portion 22. The planar shape of the region to be subjected to the coining process (that is, the thin portion 21) is such that the straight portion 21 a parallel to the long side of the planned bottom portion 22 and the end portion of the straight portion 21 a away from the planned bottom portion 22. And a shaded portion 21b provided. The hatched portion 21 b is provided in the final molded product 50 so as to be substantially parallel to the boundary line between the side wall including the long side of the bottom plate portion 53 and the side wall including the short side of the bottom plate portion 53. Hereinafter, for convenience of explanation, the side wall including the long side of the bottom plate portion 53 is referred to as a first side wall 51, and the side wall including the short side of the bottom plate portion 53 is referred to as a second side wall 52. In FIG. 10, the dotted line portion 21 Z corresponds to the thin portion 21 provided in the blank 20, and the straight portion 21 Zb corresponds to the shaded portion 21 b in the thin portion 21. Moreover, in this embodiment, although the line 21c which connects the both ends of a pair of oblique line part 21b is comprised by the circular arc-shaped line, this line 21c may be a straight line.

<Drawing and ironing process for blanks>
In particular, a drawing and ironing process for the blank 20 will be described with reference to FIGS. 4 and 5 are explanatory views of the drawing and ironing process (drawing and ironing process for the blank 20) according to the embodiment of the present invention. 4 and 5 are schematic cross-sectional views showing the main part of the processing apparatus for drawing and ironing, FIG. 4 shows a state before processing, and FIG. 5 shows a state immediately after processing. Yes. Further, in FIGS. 4 and 5, the right side of the alternate long and short dash line shows the processed portion when the portion that becomes the first side wall 51 is viewed from the front, and the left side of the alternate long and short dash line shows the portion that becomes the second side wall 52. The process part at the time of seeing from the front is shown. FIG. 6 is a perspective view of an intermediate molded product (hereinafter, referred to as a first intermediate molded product 30 for convenience of explanation) that has been subjected to drawing and ironing on the blank 20 according to the embodiment of the present invention.

The drawing ironing apparatus according to the present embodiment includes a punch (hereinafter referred to as a first punch 510 for convenience of description), a die (hereinafter referred to as a first die 610 for convenience of description), a blank pressing member 710, And a receiving member (hereinafter referred to as a first receiving member 810 for convenience of explanation). The first punch 510 is configured to move toward the first die 610, and the first die 610 is formed with a through hole 611 into which the first punch 510 is inserted. The blank presser member 710 is provided to prevent wrinkles from being formed on the blank 20 during the drawing and ironing process. The 1st receiving member 810 is provided in order to maintain the planar state of the baseplate part 33 in the 1st intermediate molded product 30 at the time of drawing ironing. The first receiving member 810 is supported by a spring 811 so that it can be retracted to the opposite side of the first punch 510 while resisting the pressure received from the first punch 510. With the drawing ironing apparatus configured as described above, drawing ironing is performed on the blank 20 that has been subjected to coining.

The blank 20 that has been subjected to the coining process is placed on the first die 610 while being sandwiched between the first die 610 and the blank pressing member 710 (see FIG. 4). The blank 20 is pressed by the first punch 510. Thereby, the blank 20 is plastically deformed so as to follow the tip shape of the first punch 510. Here, the thickness of the blank 20 (the thickness of the portion excluding the thin portion 21) is equal to the thickness t1 of the original metal plate 10. When the gap between the first punch 510 and the through hole 611 provided in the first die 610 is S1, S1 <t1 is set. Thereby, in the process in which the first punch 510 is inserted into the through hole 611 provided in the first die 610, the portion of the blank 20 that is drawn between the first punch 510 and the through hole 611 is squeezed. Become thinner.

The first intermediate molded product 30 subjected to the drawing and ironing process includes an elliptical bottom plate portion 33, a side wall portion 31 including a portion having a large curvature radius in the bottom plate portion 33, and a portion having a small curvature radius in the bottom plate portion 33. And a side wall portion 32 including About a pair of thin part 21X currently formed in the baseplate part 33 of this 1st intermediate molded product 30, there is almost no change from the shape of a pair of thin part 21 currently formed in the blank 20. FIG.

<Drawing and ironing process for intermediate molded products>
In particular, the drawing and ironing process for the first intermediate molded product 30 will be described with reference to FIGS. 7 and 8 are explanatory views of a drawing and ironing process (drawing and ironing process for the first intermediate molded product 30) according to the embodiment of the present invention. FIGS. 7 and 8 are schematic cross-sectional views showing the main part of a processing apparatus for drawing and ironing, FIG. 7 shows a state before processing, and FIG. 8 shows a state immediately after processing. Yes. Furthermore, in FIG.7 and FIG.8, the right side from the dashed-dotted line has shown the process part at the time of seeing the part used as the 1st side wall 51 from the front, and the left side from the dashed-dotted line shows the part used as the 2nd side wall 52. The process part at the time of seeing from the front is shown. FIG. 9 is a perspective view of an intermediate molded product (hereinafter, referred to as a second intermediate molded product 40 for convenience of explanation) in which the drawing and ironing process has been performed on the first intermediate molded product 30 according to the embodiment of the present invention.

The drawing ironing apparatus according to the present embodiment includes a punch (hereinafter referred to as a second punch 520 for convenience of description), a die (hereinafter referred to as a second die 620 for convenience of description), and an annular blank (cup ) Holder 910 and a receiving member (hereinafter referred to as second receiving member 820 for convenience of explanation). The second punch 520 is configured to move toward the second die 620, and the second die 620 is formed with a through hole 621 into which the second punch 520 is inserted. The blank holder 910 is provided to hold the first intermediate molded product 30 on the second punch 520. A spring 911 is provided on the rear end side of the blank holder 910 and is configured to be movable up and down in the drawing. The second receiving member 820 is provided to maintain the flat state of the bottom plate portion 43 in the second intermediate molded product 40 during drawing ironing. The second receiving member 820 is supported by a spring 821 so that it can be retracted to the opposite side of the second punch 520 while resisting the pressure received from the second punch 520. Drawing and ironing is performed on the first intermediate molded product 30 by the drawing and ironing apparatus configured as described above.

The first intermediate molded product 30 is held by the second punch 520 by being fitted to the outer periphery of the annular blank holder 910. Then, the first intermediate molded product 30 is pressurized by the second punch 520. Thereby, the first intermediate molded product 30 is plastically deformed so as to follow the tip shape of the second punch 520. Here, in the process in which the second punch 520 is inserted into the through hole 621 provided in the second die 620, only the second punch 520 and the first intermediate molded product 30 are inserted into the through hole 621, and the blank holder 910 is It collides with the second die 620 and is not inserted into the through hole 621.

Here, in the first intermediate molded product 30, the thickness of the portion that has already been subjected to the drawing and ironing process is t2 (<t1), and the second punch 520 and the through hole 621 provided in the second die 620 When the gap is S2 (<S1), S2 <t2 is set. Thereby, in the process in which the second punch 520 is inserted into the through hole 621 provided in the second die 620, the portion of the first intermediate molded product 30 that is drawn between the second punch 520 and the through hole 621 is Furthermore, it becomes squeezed and thinned.

The second intermediate molded product 40 thus obtained includes an elliptical bottom plate portion 43, a side wall portion 41 including a portion having a large curvature radius in the bottom plate portion 43, and a portion having a small curvature radius in the bottom plate portion 43. And a side wall portion 42 including Here, the planar shape of the bottom plate portion 43 of the second intermediate molded product 40 is an elongated oval shape than the planar shape of the bottom plate portion 33 of the first intermediate molded product 30. In addition, the height of the

side wall portions

41 and 42 in the second intermediate molded product 40 is higher than the height of the

side wall portions

31 and 32 in the first intermediate molded product 30.

In addition, the radius of curvature of the corner between the tip surface and the side surface of the second punch 520 is smaller than the radius of curvature of the corner between the tip surface and the side surface of the first punch 510. Has been. Thereby, the curvature radius of the corner between the bottom plate portion 43 and the

side wall portions

41 and 42 in the second intermediate molded product 40 is the same as that between the bottom plate portion 33 and the

side wall portions

31 and 32 in the first intermediate molded product 30. It is smaller than the radius of curvature of the corners between them.

Further, in the present embodiment, a drawing process is performed on a part of the pair of thin portions 21X formed on the bottom plate portion 33 of the first intermediate molded product 30 by a drawing ironing process on the first intermediate molded product 30. ing. In the second intermediate molded product 40 shown in FIG. 9, a portion indicated by reference numeral 21 Y corresponds to a portion where the thin portion 21 X is formed in the first intermediate molded product 30.

In the present embodiment, the second intermediate molded product 40 is further subjected to drawing and ironing. The apparatus and the processing method for performing the drawing and ironing process on the second intermediate molded product 40 are the same as the apparatus and the processing method for performing the drawing and ironing process on the first intermediate molded product 30. The description is omitted.

The final intermediate product 50 is obtained by drawing and ironing the second intermediate product 40 (see FIG. 10). The final molded product 50 includes a bottom plate portion 53 having a substantially square planar shape, a first side wall 51 including a long side in the bottom plate portion 53, and a second side wall 52 including a short side in the bottom plate portion 53. Then, an unnecessary outer edge portion 55 formed in the vicinity of the opening of the final molded product 50 is cut off by trimming, whereby a rectangular can 60 that is the final product is obtained (see FIG. 11).

In addition, the thickness of the 1st side wall 51 and the 2nd side wall 52 in the final molded product 50 and the square can 60 is thinner than the thickness of the

side wall parts

41 and 42 in the 2nd intermediate molded product 40. This is because the drawing and ironing process is further performed on the second intermediate molded product 40. Further, as described above, in FIG. 10, the dotted line portion 21 Z shown in the first side wall 51 corresponds to the thin portion 21 provided in the blank 20. Here, the drawing and ironing process is performed on the entire thin portion 21 by the second and third drawing and ironing processes. Accordingly, the thickness of the first side wall 51 is thinner than the thickness t11 of the thin portion 21. Furthermore, the curvature radius of the corner between the bottom plate portion 53 and the first side wall 51 and the second side wall 52 in the final molded product 50 and the square can 60 is the same as the bottom plate portion 43 and the side wall portion in the second intermediate molded product 40. It is smaller than the radius of curvature of the corner between 41 and 42.

<The excellent point of the manufacturing method of the square can which concerns on this embodiment>
According to the manufacturing method of the square can 60 according to the present embodiment, at least a part of the metal plate 10 (blank 20) to which the drawing and ironing process is performed is subjected to a coining process in advance. Thereby, since the thickness of the metal plate is reduced in advance, the amount (ratio) of reducing the thickness of the metal plate by drawing ironing can be reduced. Therefore, stress on the portions corresponding to the four corners of the bottom plate portion 53 of the square can 60 can be reduced. Therefore, even if the curvature radii at the four corners of the bottom plate portion 53 of the square can 60 are reduced, it is possible to suppress the occurrence of cracks or cracks in the portions. As described above, it is possible to reduce the curvature radii at the four corners of the bottom plate portion 53 of the square can 60 as compared with the case where coining is not performed. In addition, since coining is performed on the metal plate 10 and then squeezing and ironing is performed, distortion of the bottom plate portion 53 can be suppressed. Furthermore, since the coining process is performed on the metal plate 10, the planar shape of the thin portion 21 and the degree of compression (crushing amount) in the coining process are high, and thus cracks and cracks are generated. The curvature radii at the four corners of the bottom plate portion 53 of the rectangular can 60 can be made smaller while being suppressed.

It should be noted that the stress can be further reduced by increasing the amount of coining (thinning the thickness t11 of the thin portion 21 as much as possible with respect to the thickness t1 of the metal plate 10). That is, if the amount of coining is increased, the ironing rate can be reduced. Here, the ironing rate is ((thickness before drawing ironing) − (thickness after drawing ironing)) ÷ (thickness before drawing ironing). By reducing the ironing rate, the burden on the metal is reduced and the stress can be reduced. In addition, when the ironing rate on the first side wall 51 side and the ironing rate on the second side wall 52 side are close to each other, the stress is reduced and cracks and cracks are generated at the four corner portions of the bottom plate portion 53. It was confirmed that it can be suppressed.

(Other)
<Modification of the area to be coined>
The region where the coining process is performed on the metal plate 10 is not limited to the region described in the above embodiment. Hereinafter, a modification of the area to be subjected to coining will be described. The coining process is performed on at least part of the periphery of the planned bottom portion of the metal plate (blank). FIG. 12 is a plan view of Modification Example 1 of the blank subjected to coining according to the embodiment of the present invention. In the blank 20X shown in the first modification, coining is performed along the pair of long sides in the planned bottom portion 22 to form a pair of thin portions 21 as in the case of the above embodiment. . Moreover, in this blank 20X, a coining process is given along a pair of short side in the bottom planned part 22, and a pair of thin part 23 is formed. Further, in this blank 20X, coining is applied to four regions in the vicinity of each of the four corners where the long side and the short side of the planned bottom portion 22 intersect, A thin portion 24 is formed. Furthermore, in this blank 20X, a coining process is given to a part (inside) of the planned bottom portion 22, and a thin portion 25 is also formed.

As described above, the region in which the coining process is performed on the metal plate 10 is not particularly limited. Therefore, in this blank 20X, the case where the four types of

thin portions

21, 23, 24, 25 are provided is shown, but some of the four types of

thin portions

21, 23, 24, 25 are appropriately used. They can also be used in combination.

FIG. 13 is a plan view of a second modified example of the blank subjected to coining according to the embodiment of the present invention. In the blank 20Y shown in the second modification, coining is performed so as to surround the periphery of the planned bottom portion 22, and a thin portion 26 is formed. In addition, as shown in the said modification 1, with respect to this blank 20Y, a coining process may be given to a part (inner side) of the bottom planned part 22, and the thin part 25 may be formed.

<Modification of metal plate to be coined>
In the said embodiment, the case where the metal plate 10 which performs a coining process was a blank previously cut into a fixed shape was shown. However, the metal plate to be subjected to coining may be a metal plate that is a material instead of a blank. In this case, a blank subjected to coining can be obtained by performing coining on a metal plate as a raw material and then cutting it into a certain shape.

<Modified example of drawing ironing>
In the said embodiment, the case where a drawing ironing process was given with respect to a blank and the drawing ironing process twice was shown with respect to the intermediate molded product after that was shown. However, the number of times of squeezing and ironing may be appropriately set according to the shape and dimensions of the final molded product and the rectangular can as the final product. Therefore, the blanking and ironing process may be performed only once on the blank. In addition, the ironing process may be performed three or more times on the intermediate molded product.

Also, in the above embodiment, a case has been described in which after the coining process, only the drawing and ironing process is repeated a plurality of times. However, in the present invention, cases other than the coining process and the drawing ironing process are included.

For example, after performing coining, when drawing without squeezing is performed, when redrawing is performed after the drawing, and further, when drawing is performed during the redrawing. The processing device for drawing is the same configuration as the processing device for drawing and ironing, but the gap between the punch and the through-hole provided in the die is the metal plate or intermediate molded product before processing. The point that is set larger than the thickness is different from the case of a processing apparatus that performs drawing ironing. Drawing processing without ironing can be performed by the processing apparatus configured in this manner. As described above, the present invention includes a case where the drawing process without the ironing process is performed once or more in the initial machining process and then the drawing ironing process or the ironing process is performed once or more. Of course, the present invention includes a case where a drawing or ironing process is performed in the middle of a plurality of drawing and ironing processes.

In the drawing ironing process described in the above embodiment, the relationship between the gap S1 and the thickness t1 of the original metal plate 10 is S1 = t1, and the gap S2 and the first intermediate molded product 30 are already included. The case where the relationship of the thickness t2 of the portion subjected to the drawing and ironing process is set to S2 = t2 is also included.

Further, in the above embodiment, by providing the receiving member (first receiving member 810, second receiving member 820) in the processing apparatus that performs the drawing ironing process, the plane of the bottom plate portion in the intermediate molded product during the drawing ironing process. The state is maintained. However, in the case where it is difficult to maintain the flat state of the bottom plate portion, it is also possible to shape the bottom plate portion into a flat plate shape by pressing after the drawing and ironing process. Finally, in the case of performing such press working, it is also possible to adopt a configuration in which a receiving member is not provided as a processing apparatus that performs drawing ironing.

In addition, the planar shape of the bottom plate portion of the rectangular can in the above embodiment may be a square shape in addition to a rectangular shape having a pair of long sides and short sides, and is not limited to a substantially rectangular shape. It may be a planar shape.

DESCRIPTION OF SYMBOLS 10

Metal plate

20,20X,

20Y Blank

21,21X, 23,24,25,26 Thin part 21a Straight part 21b Diagonal part 21Zb Straight part 22 Planned bottom part 30 1st intermediate molded

product

31, 32 Side wall part 33 Bottom plate part 40 Second intermediate molded

product

41, 42 Side wall portion 43 Bottom plate portion 50 Final molded product 51 First side wall 52 Second side wall 53 Bottom plate portion 55 Outer edge portion 60 Square can 100 Coining punch 200 Die 300 Metal plate pressing member 310 Through hole 510 1st Punch 520 Second punch 610 First die 611 Through hole 620 Second die 621 Through hole 710 Blank holding member 810 First receiving member 811 Spring 820 Second receiving member 821 Spring 910 Blank (cup) holder 911 Spring

Claims

A method of manufacturing a bottomed rectangular can,
A step of performing coining on at least a part of a portion corresponding to the side wall of the final molded product and a portion subjected to drawing and ironing on the metal plate,
A step of drawing and ironing the blank subjected to the coining process;
The manufacturing method of the square can characterized by including.
The method for manufacturing a rectangular can according to claim 1, wherein the coining process is performed on at least a part of a periphery of a planned bottom portion which becomes a bottom plate portion of the rectangular can.
The planar shape of the bottom plate portion of the square can is a substantially rectangular shape,
3. The method for manufacturing a rectangular can according to claim 2, wherein the coining is performed along a pair of long sides in a planned bottom portion which is a substantially rectangular bottom plate portion.
The planar shape of the area where the coining process is performed is
It is a shape having at least a straight line portion parallel to the long side and a pair of oblique line portions provided so as to be away from the planned bottom portion from an end portion of the straight line portion,
In the final molded product, the pair of hatched portions are provided so as to be substantially parallel to a boundary line between a side wall including a long side of the bottom plate portion and a side wall including a short side of the bottom plate portion. The manufacturing method of the square can of Claim 3.
The planar shape of the bottom plate portion of the square can is a substantially rectangular shape,
5. The method for manufacturing a rectangular can according to claim 2, wherein the coining process is performed along a pair of short sides of a planned bottom portion which is a substantially rectangular bottom plate portion.
The planar shape of the area where the coining process is performed is
It is a shape having at least a straight line portion parallel to the short side, and a hatched portion provided so as to be away from the planned bottom portion from an end portion of the straight line portion,
The hatched portion is provided in the final molded product so as to be substantially parallel to a boundary line between a side wall including a long side of the bottom plate portion and a side wall including a short side of the bottom plate portion. The manufacturing method of the square can of Claim 5.
The planar shape of the bottom plate portion of the square can is a substantially rectangular shape,
The coining process is performed on four regions in the vicinity of each of four corner portions where the long side and the short side intersect in the planned bottom portion which is a substantially rectangular bottom plate portion. The method for producing a rectangular can according to any one of 2 to 6.
The planar shape of the bottom plate portion of the square can is a substantially rectangular shape,
3. The method for manufacturing a rectangular can according to claim 2, wherein the coining is performed so as to surround a periphery of a planned bottom portion which is a substantially rectangular bottom plate portion.
The method for manufacturing a rectangular can according to any one of claims 1 to 8, wherein the coining process is performed on a part of a planned bottom portion which becomes a bottom plate portion of the rectangular can.
10. The method for manufacturing a rectangular can according to claim 1, wherein the coining process is performed in a state where a periphery of the area to be coined is pressed.