JP6171570B2 - Manufacturing method for bottomed cans - Google Patents

Description

  The present invention relates to a method for manufacturing a bottomed can formed by drawing or drawing and ironing, and more particularly to a method for manufacturing a bottomed can whose bottom is thinned.

Conventionally, the thickness of the can has been reduced, but when the bottomed can is formed by squeezing and squeezing, the cylindrical side wall portion is ironed and thinned, but the bottom is hardly processed, and the thickness is the thickness of the original plate. Therefore, the thickness of the bottom becomes thicker than the side wall. Therefore, if a metal plate whose original plate thickness is close to the thickness of the side wall after molding is formed as an original plate, the side wall becomes too thin, causing leftovers on the side wall, and in the case of a rectangular can, processing such as inward warping Defects occur.
Therefore, as a method for thinning the bottom of such a bottomed can, for example, a method as described in Patent Document 1 has been proposed. In this manufacturing method, a blank material is pressed to form a bottomed cylindrical intermediate molded product, and a concave portion is engraved (coined) in the center of the bottom of the intermediate molded product so that the bottom or the lower portion of the side wall has a desired thickness in advance. After that, a bottomed cylinder-formed product is manufactured by drawing and ironing.

  However, with this conventional method, the coined bottom tends to be distorted. Further, when coining is performed on a flat metal material such as a blank material, distortion or large warpage occurs in the plate-shaped intermediate formed body after coining. If distortion or warping occurs, there is a risk of hindering transport to the subsequent process or positioning to the molding die.

Japanese Patent No. 4702843

  The present invention has been made in order to solve the above-described problems of the prior art, and its object is to perform coining to reduce warpage of the plate-like intermediate molded body and distortion of the bottom of the bottomed cylindrical intermediate molded body. Therefore, it is providing the manufacturing method of a bottomed can excellent in conveyance property and positioning property.

In order to achieve the above object, the present invention forms a bottomed cylindrical shape from a metal plate material through a process including a coining process for thinning a part corresponding to the bottom part of the bottomed can and a drawing process. In the manufacturing method of bottomed cans,
The coining process is performed before the drawing process by a flat pressing member having a punch insertion hole corresponding to the coining process part around the coining process part of the metal plate material placed on the flat die. , performs hold advance, by coining punch guided in the punch inserting hole, the coining portion of the metal plate material, to plastically deform the thin and compressed in the thickness direction between the die structure so,
The peripheral edge of the opening on the die side of the punch insertion hole of the pressing member has a sloped shape gradually inclined in a direction away from the die, or a curved corner shape,
The pressing member is pressed around the coining processed portion in a state where a gap corresponding to the corner cutting shape is provided at the edge of the coining processed portion, and warping is caused by rising of the metal material corresponding to the gap during coining processing. Further, it is characterized in that the thickness is secured by turning a metal material to the connecting portion between the bottom portion and the side wall portion during the drawing .
The present invention preferably has the following configuration.
1. The coining process is performed at the metal band stage.
2. The coining process is performed at the metal plate stage.
3 . The coining process is performed at the stage of the metal plate material.
4 . The drawing process is performed in a plurality of stages, and the coining process is performed at the stage of the intermediate formed body before the final drawing process.
5 . After the drawing, ironing is performed.
6 . The bottomed can is a rectangular can.

  According to the present invention, it is possible to reduce the thickness of the portion corresponding to the bottom of the bottomed can, and reduce warping of the plate-shaped intermediate molded body and distortion of the bottom of the bottomed cylindrical intermediate molded body. In addition, it is possible to manufacture a bottomed thin can having excellent positioning properties.

Further, the inner peripheral edge of the opening on the die side of the punch insertion hole of the pressing member has a sloped shape or a curved corner shape gradually inclined in a direction away from the die, and the pressing member the pressing of the periphery of the coining portion by, be performed in a state where the provided gap that corresponds to a corner cut shape the edge of the coining portion, the protrusion of the metallic material corresponding to the gap, the warp is suppressed, also, A metal material can be sufficiently turned around the connecting portion between the bottom portion and the side wall portion, which is likely to be thinned by drawing and ironing, so that the thickness can be secured and the ironing residue can be suppressed.
In addition, if coining is performed before drawing, such as metal strips, metal plates, and metal plate-like materials, the coining punch and blank presser can be moved more than when processing into a bottomed cylindrical intermediate molded body after drawing. The stroke can be shortened and coining can be performed easily and efficiently.
In particular, if you perform coining on the metal band before blanking and then perform blanking and drawing at the machining position at the same time, the positional relationship between the coining tool and the blanking tool, By appropriately setting the feed pitch and the like, the positional relationship between the coining position before the coining process and the cut edge (cut edge) of blanking can be matched relatively easily and accurately.
Furthermore, as described in item 5 above, if coining is performed in the drawing process before the final drawing process, the distortion of the bottom of the intermediate molded body can be reduced. Moreover, if it performs at the stage of an intermediate molded object, the position of coining can be set correctly by guiding and positioning a side wall part.

It is the schematic which shows the process of the manufacturing method of a bottomed can which concerns on embodiment of this invention, (A)-(F) is a perspective view, (G)-(L) is a longitudinal cross-sectional view. FIGS. 2A and 2B are diagrams showing a mold configuration of a coining process, and FIG. 2C is an enlarged cross-sectional view of a coining processing portion. FIGS. 3A and 3B are diagrams for explaining the form of a metal plate material to be coined, in which FIG. 3A is a diagram performed on a metal blank, FIG. 3B is a diagram performed on a metal plate, and FIG. . FIG. 4 shows a bottomed can manufactured by the manufacturing method of FIG. 1, (A) is a perspective view, and (B) is a longitudinal sectional view.

The present invention will be described in detail below based on the embodiments shown in the drawings.
FIG. 4 shows an example of a bottomed can to which the manufacturing method of the present invention is applied.
The bottomed can 1 is, for example, a rectangular can used for a battery outer container or the like, and has a rectangular bottom portion 2 and a rectangular tube shape that surrounds and integrally forms the bottom portion 2 and has a rectangular horizontal cross section. And a side wall 3. The side wall portion 3 has a pair of long side surface portions 31 having the long side of the bottom portion 2 as a lower side, and a pair of short side surface portions 32 having a short side of the bottom portion 2 as a lower side.
This bottomed can 1 is formed into a bottomed cylindrical shape by drawing or drawing ironing from a metal strip sent out from a metal coil or a flat metal blank punched out of a metal plate-like material such as a metal plate. Thus, the bottom 2 is compressed by coining, and is made thinner than the thickness of the metal plate material. The thickness t3 of the side wall 3 is determined by drawing or drawing and ironing. In this example, the thickness t2 of the bottom 2 and the thickness t3 of the side wall 3 are substantially the same by drawing and ironing. The thickness is set.

Next, the manufacturing process of the said bottomed can 1 is demonstrated with reference to FIG.1 and FIG.2.
The bottomed can 1 is manufactured through a blanking process, a multi-stage drawing process, and an ironing process. FIG. 1 schematically shows a molded state at each stage.
1A and 1G show a metal blank 50 before coining. The metal blank 50 is an elliptical flat plate, and is formed by punching from a metal plate 500A shown in FIG. 3A or a metal strip fed from a metal coil (not shown).
An aluminum-based material is used as the metal material, but is not particularly limited, and other metal materials can be used.

In the present embodiment, coining is performed at the center of the metal blank 50 to form a coining blank 51 in which a bottom corresponding portion 52 corresponding to the bottom 2 of the bottomed can 1 of the final product is formed. In the coining process, the metal blank 50 is compressed in the thickness direction by a coining punch, and FIG. 2 shows a configuration example of a processing apparatus.
This processing apparatus presses the flat die 101 on which the metal blank 50 is placed , the blank presser 103 as a pressing member for pressing the metal blank 50 on the die 101, and the metal blank 50 on the die 101 by a press (not shown). The coining punch 105 is provided. The blank presser 103 is provided with a punch insertion hole 104 in which a coining punch 105 can protrude and retract, and the coining punch 105 is guided by the punch insertion hole 104 of the blank presser 103 to pressurize a predetermined region 53 of the metal blank 50. It has become. (See FIG. 3A. Note that FIGS. 2A and 2B correspond to arrows A and B in FIG. 3A.)

The tip 106 of the coining punch 105 is a rectangular flat surface that matches the shape of the bottom of the final molded product, and the peripheral edge 106 a has a slope or curved surface that gradually slopes away from the die 101. It has a rounded corner shape.
Also, the inner peripheral edge 104a of the opening on the die 101 side of the punch insertion hole 104 of the blank presser 103 has a sloped shape or a curved corner shape gradually inclined in a direction away from the die.

When the metal blank 50 is pressed by the coining punch 105, the metal blank 50 is compressed between the coining punch 105 and the die 101 in the thickness direction, plastically deformed, and formed into a thin wall. At this time, if the metal blank 50 is previously pressed by the blank presser 103, abnormal movement during the coining process of the metal blank 50 can be suppressed, and warping and distortion of the coining blank 51 after processing can be suppressed, and the coining is preferably performed. Can be processed. By suppressing the warping of the coining blank 51, it becomes easy to carry to the next process, or to position and set to a drawing mold.
As shown in FIG. 2C, the wall thickness t2 is set smaller than the plate thickness t1 of the metal blank 50 and the same as the wall thickness of the bottom 2 of the final molded product. The wall thickness t2 may be managed by controlling the pressing force of the coining punch 105, but it is easy and preferable to manage the wall thickness t2 by controlling the stroke of the coining punch 105 with respect to the die 101 (punch lowering position).
Further, the coining process is performed in a state in which the periphery of the bottom corresponding portion 52 formation portion of the metal blank 50 is not horizontally surrounded by the die 101, and further, the cornering of the coining punch 105 or the blank presser 103 is performed. It is performed in a state where a gap is provided at the edge of the portion corresponding to the bottom corresponding portion 52 formation due to the shape. For this reason, the metal material around the bottom corresponding portion 52 to be coined rises without being restricted. Then, the warping of the coining blank 51 is suppressed by the raised portion of the metal material, and the metal material is sufficiently turned around the connecting portion between the bottom portion and the side wall portion, which is likely to be thinned by drawing and ironing, and the thickness is increased. It can be secured, and ironing residue can be suppressed.
Further, since the coining process is performed in the state of the flat metal blank 50, the movable stroke of the coining punch 105 and the blank presser 103 can be shortened compared with the processing to the bottomed cylindrical intermediate molded body after the cup molding, and it is easy. Coining can be performed efficiently.

1 (C) and 1 (I) show the process of squeezing the metal blank 51 of FIGS. 1 (B) and 1 (H) to form an intermediate formed body 60, FIGS. 1 (D), (J) and 1 (E), (K) is a step of drawing the intermediate formed body 60 stepwise to form intermediate formed bodies 70 and 80, and FIGS. 1 (F) and (L) are the intermediate formed body 8.
The figure shows the process of squeezing and squeezing 0 to adjust the side wall 33 to a predetermined thickness as the shape of the bottom 2 of the bottomed can 1 of the final molded product, and forming an intermediate molded body 90 with gloss on the surface. It is a figure.
In this way, the area of the bottom portions 61, 71, 81, 91 of the intermediate molded bodies 60, 70, 80, 90 is gradually increased in each process from the wide area of the bottom portion 61 of the intermediate molded body 60 to the final molded product 90. Although it is gradually narrowed to the bottom 91, the periphery of the bottom corresponding portion 52 by the coining process is narrowed down, and the thickness of the bottom of the intermediate molded body in each step is processed with the thickness after the coining process substantially. In the final drawing and ironing process step, the portion of the metal material raised around the bottom corresponding portion 52 can be effectively turned to the side wall portion 33.
Then, the open end of the intermediate molded body 90 is trimmed by trimming, and the bottomed can 1 as the final molded product shown in FIG. 4 is molded.
According to the present invention, since the long side surface portion 31 and the short side surface portion 32 are formed using a metal plate having a thick original plate thickness, coining is performed while adjusting the wall thickness of the side wall portion 33 while preventing inward warping and ironing. The bottomed can 1 having the bottom 2 thinned by the above can be formed.

In the above embodiment, the timing of the coining process has been described by taking the time point of the metal blank 50 as an example, but it may be performed before the blanking step. For example, as shown in FIG. 3B, after performing coining by previously pressing the predetermined region 53 on the metal plate 500A before blanking, blanking and drawing are simultaneously performed on the metal plate 500A ′ after coining. As shown in FIG. 3 (C), after feeding out from the metal coil and coining by previously pressing the predetermined region 53 against the metal band 500B before blanking, blanking is performed at the processing position C. Drawing may be performed simultaneously. In this case, by properly setting the positional relationship between the coining tool and the blanking tool, the feed pitch of the metal band (or metal plate), etc., the coining position before the coining process and blanking cut edge (cutting) The positional relationship with the edge can be adjusted relatively easily and accurately.
Further, the timing of the coining process may be a drawing process, in which case the drawing process is performed in the drawing process before the final drawing process to form the bottom 2 of the bottomed can 1 of the intermediate molded product 90, and the process shown in FIG. In the case of performing redrawing and ironing at the above, since the redrawing process becomes the final drawing process, the drawing process shown in FIGS. 1C to 1E and 1I to K before the final drawing process. Coining is performed on the bottom of the intermediate molded body.
Even when coining is performed at these intermediate stages, the bottom portions 61, 71, 81 are pressed in advance by pressing the bottom portion around the bottom corresponding portion 52 of the intermediate molded body in the same manner as the pressing by the previous blank presser 103. Distortion can be reduced.
Further, if coining is performed at the stage of such intermediate molded bodies 60, 70, 80, the position of coining can be accurately set by guiding and positioning the side wall parts 63, 73, 83.

Further, in the present embodiment, a rectangular can is described as an example of a bottomed can, but the bottomed can to which the manufacturing method of the present invention is applied is not limited to a rectangular can, but a bottomed rectangular tube shape The present invention can be widely applied to bottomed cylindrical cans such as polygonal rectangular cans, round and elliptical round cans.
Further, the relationship between the thickness of the side wall and the thickness of the bottom, such as the long side surface and the short side surface of the bottomed can, is not particularly limited.
Furthermore, the ironing process may be performed in a process different from the drawing process, or the ironing process may be omitted.

DESCRIPTION OF SYMBOLS 1 Bottomed can, 2 Bottom part, 3 Side wall part 31 Long side part, 32 Short side part 50 Metal blank 51 Coining blank 52 Bottom part corresponding | compatible part 60,70,80,90 Intermediate molded object 61,71,81,91 Bottom 33 Side wall Part 101 die,
103 Blank presser 104 Punch insertion hole, 104a Opening inner periphery 105 Coining punch 106 Tip, 106a Perimeter t2 Bottom wall thickness t3 Side wall wall thickness

Claims (7)

In the manufacturing method of a bottomed can formed from a metal plate-like material through a process including thinning a part corresponding to the bottom of the bottomed can, and a process including a drawing process,
The coining process is performed before the drawing process by a flat pressing member having a punch insertion hole corresponding to the coining process part around the coining process part of the metal plate material placed on the flat die. A structure in which the coining punch of the metal plate material is compressed in the thickness direction between the die and plastically deformed by a coining punch guided in the punch insertion hole. so,
The peripheral edge of the opening on the die side of the punch insertion hole of the pressing member has a sloped shape gradually inclined in a direction away from the die, or a curved corner shape,
The pressing member is pressed around the coining portion in a state where a gap corresponding to the corner cutting shape is provided at the edge of the coining portion, and warped due to the rise of the metal material corresponding to the gap during the coining process. Further, a method for producing a bottomed can characterized by ensuring a thickness by turning a metal material to a connecting portion between the bottom and the side wall during the drawing process.   The method for producing a bottomed can according to claim 1, wherein the coining process is performed at a stage of a metal strip.   The method for manufacturing a bottomed can according to claim 1, wherein the coining process is performed at a stage of a metal plate.   The method for manufacturing a bottomed can according to claim 1, wherein the coining process is performed at a stage of a metal blank.   The method for producing a bottomed can according to claim 1, wherein the drawing is performed in a plurality of stages, and the coining is performed in a stage of an intermediate formed body before the final drawing.   The method for producing a bottomed can according to any one of claims 1 to 5, wherein ironing is performed after the drawing. The method for producing a bottomed can according to any one of claims 1 to 6 , wherein the bottomed can is a rectangular can.

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