EP2790847A2

EP2790847A2 - Method for producing a container body

Info

Publication number: EP2790847A2
Application number: EP12791736.7A
Authority: EP
Inventors: Carsten BRECHTLING
Original assignee: L Schuler GmbH
Current assignee: L Schuler GmbH
Priority date: 2011-12-15
Filing date: 2012-11-14
Publication date: 2014-10-22
Also published as: WO2013087332A2; US20150352624A1; WO2013087332A3; DE102011056462A1; DE102011056462B4

Abstract

The invention relates to a method for producing a container body. For this purpose, a disc-shaped round blank (10) with a circular cylindrical contour is first punched out of a metal sheet, in particular an aluminium sheet. The two circular edges (15) of the round blank (10) are then formed into a predetermined desired shape in a compression process. During said compression process, the peripheral surface (16) of the round blank (10) bordered by the two edges (15) rolls off in a compressed groove (19) of a compression tool (18), said compressed groove determining the edge shape. This produces a symmetrical shape opposite a symmetrical plane (S), which runs centrally between the two flat sides of the round blank (10). The round blank (10) can therefore be fed to a forming device (22) without the need for sorting and orientation. The round blank (10) can thereby be turned towards a stamp (23) or a forming die (24) with any one of its flat sides (13). It is therefore possible for the round blank (10) to be fed, in two different positions, into the forming position (P) of the forming device (22), without the forming process or the container body being negatively influenced as a result.

Description

Method for producing a container body

The invention relates to a method for producing a container body, which is made of a blank called Ronde seam and joint free. In ^¬ play, the container body has a cylindrical Be ^¬ container wall, which passes axially at one end in a container ^¬ part which closes the container body, such as a container bottom. The produced container body can thus be axially at one end by the container part CLOSED ^¬ sen, or can have at both ends an opening. At at least one axial end, the container body is open. Such container bodies may for example be produced by extrusion to produce tubes, cans or the like made of metal, for example aluminum, or a metal alloy. The shape of the container body may vary depending on the design of the die and the punch.

A flow press for the production of such container bodies is known, for example, from DE 1 402 784 A. Circles or blanks are fed to the extrusion press and positioned between dei ^¬ ner die and a stamp. This stamp presses the board into the matrix. In this case, the material flows against the direction of movement of the stamp around it and thereby also out of the die, wherein between the container body is formed. Alternatively, this backward extrusion process are also Vorwärtsfließpress- or combined forward-backward extrusion process is known in which the material is finally ^¬ or additionally also in the movement direction of the Stamp flows.

Another method for producing a container body by deep-drawing-stretching is described for example in DE 2 308 132 or DE 10 2010 000 094 AI. First, blanks are punched out of a sheet metal. These are then pulled in an ironing station with the aid of a drawing punch through a die and thereby vice ^{¬ formed} .

Extrusion molding processes for can production are known and have been used for a long time. However, in these methods, it is necessary to place the punched disc-shaped blanks, which are also referred to as blanks, in a desired orientation before the extrusion presses for forming the container body. This is necessary because the blanks or blanks have a punching burr after punching. As a rule, this stamping burr is not disturbing for the production of the container body since the edge of the container wall opposite the container bottom is cut off anyway after the disk-shaped blank has been formed into the container body. Bumps on this edge, which are formed by the burr, are therefore unproblematic.

However, this requires the alignment of the blank or the blank prior to the extrusion such that the punching burr having flat side is associated with the axially open end of the container body to be produced. In fal ^¬ shear orientation of the blank prior to extrusion can occur in the wall by the burr holes in the container wall or so-called duplication. This is the case when the burr is pressed against the flow direction of the material in or through the die. This problem has been known for a long time. It is becoming nowadays achieved in that at the same time a deformation takes place ^¬ when punching the disc-shaped blank or the blank, in which the Ronde is curved. This is called Bom ^¬ beers. Due to the bulging of the blank this is unevenly shaped on both sides. Therefore, a sorting is possible when feeding or transporting the blanks to the forming station, so that the blank always has the desired orientation in the flow direction of the material with the punching burr. Such sorting is expensive. Even when sorting errors can occur, which in turn draw errors when forming the blank in the container body.

When thermoforming-stripping of blanks to container bodies they are usually picked up by a gripping device and placed between the drawing punch and the die. It may happen that flat superimposed discs stick to each other and accidentally grabbed two rounds and fed to the press. This leads to errors.

It can therefore be regarded as an object of the present invention to provide a method which is less expensive and avoids errors in forming the blank into the container body or at least markedly reduced.

This object is achieved by a method with the features of claim 1.

According to the invention, a disk-shaped blank having a preferably circular contour is first punched out of a metal sheet. With a circular contour, the blank can also be referred to as a round blank. After punching, the two edges of the blank are removed. compresses. Due to this upsetting process, any existing punching burr is removed. The disk-shaped blank thus obtains a symmetrical shape with respect to a Sym ^¬ metry plane, which runs centrally between the two flat sides of the blank. By upsetting the two edges and the resulting symmetrical shape of the blank, a subsequent sorting is superfluous. The blank can be transported with any of its two flat sides in a forming position, from which it is then converted, for example, in an extrusion process to the container body. By upsetting the two annular edges also a calibration of the blank is achieved. Irregularities of the punching process are ent ^¬ removed. The Known receive a precisely predetermined shape and can therefore be easily arranged in the desired forming position, which in turn avoids errors in the forming process. Also, the transporting or feeding the disc-shaped blanks to the forming station is simplified, since all the blanks, apart from minor process tolerances during upsetting, have the same shape and irregularities of the stamping process are removed. To trans ^¬ transporting blanks are flat and have no irregular burr on.

The deformation of the blank in the container body can be done for example by extrusion. In the forming position, the blank may be arranged between a punch in the upper tool of the press and a die in the lower tool of the press. Preferably, the blank is in the forming position with one of its two flat sides to a support surface of the forming die, which beispielswei ^¬ se surrounding the die ring.

Preferably, when upsetting the two edges of the blank both edges are processed simultaneously. This is a high throughput and an efficient manufacturing process can be achieved. For the upsetting of the two edges of the blank are, for example, machines, as used for Randstau ^¬ chen and / or embossing coins. Such machines are available in the market and can be used very simply for the method according to the invention. Although the container body preform is preferably made of aluminum, it has been found that the machines used for edge dipping of coins are also suitable for edge dipping of the aluminum blanks stamped for container body production. Aluminum is a very soft material. Nevertheless, an upsetting of the edges to achieve the desired shape could be achieved without adversely affecting the cylindrical disk-shaped Ge ^¬ stalt the Ronde.

During the upsetting, the blank with its peripheral surface, which is bounded by the two edges to be crushed, is preferably rolled on an upsetting tool. By a pressure forming process, the two edges are compressed and brought into the desired shape. The shape of the blank or of the blank in the region of the edges and the peripheral surface is predetermined by the upsetting tool. In a preferred embodiment, an upsetting groove in the upsetting tool is present for this purpose, in which the Ron ^¬ de rolls with the peripheral surface.

By upsetting the Ronde can be formed at the two edges of a radius, a circumferential chamfer or a ring ^¬ circumferential edge. Such an edge can for example serve to simplify the positioning of the blank in the forming position.

Advantageous embodiments of the method are derived from the dependent claims and the Sensitive. The description is limited to essential features of the invention and other conditions. Reference to the drawings preferred embodiments of the invention will be explained. Show it:

1 shows a strip-shaped sheet in a schematic representation as a starting material for punching round blanks,

Figure 2 is a schematic, block-diagram Dar ^¬ position of the punching operation,

Figure 3 is a partial sectional view of the kingdom Randbe ^¬ a circular blank after punching,

FIG. 4 shows a first exemplary arrangement for ^stowing the edges of the blank in a partial representation;

FIG. 5 shows a second exemplary arrangement for ^stowing the edge of the blank in a partial representation;

6 to 8 show a partial sectional view according ^¬ weils a circular blank after upsetting with different edge shapes, and

9 to 11 show an exemplary representation of a heavily catalyzed schemati ^¬ extrusion process.

The invention relates to a method for producing a container body with an example according to Hohlzylind ^¬ rical shape, which in the preferred embodiment at one axial end open and at the other axial end seamlessly and without joints passes into a container part, which closes the container body. Alternatively, a container body can be produced by extrusion, which is open at both axial ends. The container body is made from a disk-shaped cylindrical blank 10. In the present method, the blank has a circular contour and is therefore hereinafter referred to as Ronde 10.

In a first method step, the blanks 10 are punched out of a metal sheet 11, which consists for example of aluminum. The metal sheet 11 can be handled as a tape-like material from a roll and punched out by means of a punching tool 12, as is illustrated specific ^¬ matic in FIG. 2

After punching, the blank 10 has a punched burr 14 on one of its two flat sides 13. This punching burr 14 is irregular and causes a non-symmetrical shape of the blank 10.

After punching out of the blank 10, an upsetting process is carried out to remove the punching burr 14 and to produce a symmetrical shape with respect to a symmetry plane S in the middle between the two flat sides 13. The two annular edges 15, the circumferential surface, the environmental will limit 16 of the blank 10, is compressed and placed in egg ^¬ ne desired shape. In Figures 6 to 8 show various embodiments of blanks 10 are ^¬ represents Darge, each round blank 10 has a different shape on edges ^¬. By upsetting an edge 15, a radius R, a chamfer F or a circumferential projection to form a rim V are formed. The projection or edge V has in the embodiment shown in Figure 6 has a rounded shape and is closed annularly. He stands beyond the respective adjacent flat side 13 and goes continuously into the peripheral surface 16 on. The ge ^¬ stauchte edge 15 of the blank 10 may be rounded or edge bounded in the circumferential surface 16 and / or override the supplied ^¬ arranged flat side. 13 The edge 15 projects all ^¬ recently addition, in any embodiment, on the circumferential surface by the environmental 16 defined cylinder surface.

In FIGS. 4 and 5, upsetting devices 17 for compressing the two edges 15 of the blank 10 are illustrated schematically. The compression device 17 has an upsetting tool 18 with an upsetting groove 19. The upsetting groove 19 extends along a circle segment. Accordingly, the compression tool 18 may have a ring-segment-like contour. A distance from the upsetting tool 18 and the upset groove 19 is coaxial with the upset groove 19 a drive wheel 20 having a At ^¬ triebsnut 21. The blank 10 is received for upsetting in the drive groove 21 of the drive wheel 20 and deselected along the upset groove 19 of the upsetting tool 18. In order to compress the entire edge 15 of the length of the upset groove 19 corresponds at least to the circumference of the two edges 15 of the blank 10. The cross-sectional shape of the upset groove 19 be ^¬ adjusts the shape of the edge 15 after the swaging process. The blank 10 is clamped during upsetting between the drive wheel 20 and the stationary upsetting tool 18, whereby the two edges 15 deform in the upset groove 19 and adapted to the shape of the upset groove 19.

The two embodiments of the compression devices 17 in Figures 4 and 5 operate on the same principle. In both cases, the drive groove 21 and the Upset groove 19 arranged coaxially to the drive axis of the drive wheel 20. In the embodiment of Figure 1, the radius of the compression groove 19 is greater than the radius of the drive ^¬ nut 21. In this first embodiment, the upset groove 19 has a greater distance from the drive axis of the drive wheel 20, as the drive groove 21. In contrast, in the second embodiment according to Figure 5, the drive groove 21 and the upset groove 19 axially spaced zuei ^¬ arranged one another and both have the same distance from the drive axle. Again, the two grooves 19, 21 are arranged coaxially with the drive axle.

Further modifications of the embodiments of the compression device 17 are possible. For example, the upsetting tool, may in a modification of the first embodiment shown in Figure 4 may be 19 disposed within the drive wheel 20 so that the distance between the upset groove 19 is less to the drive axis than the spacing of the drive groove 21. In al ^¬ len embodiments, the upset groove 19 and the drive groove 21 aligned with each other, so that the Ronde 10 engage both in the upset groove 19, and in the on ^¬ driving groove 21 and in both grooves 19, 21 can roll.

After upsetting, the blanks 10 are finally transported to a forming device 22, which is shown very schematically simplified in the figures Figure 9 to ll. The blanks 10 are positioned for forming in a forming position P in a die 23 of the forming device 22. To the forming device 22 further includes a punch 24 which is movable relative to the die 23 along its punch longitudinal axis. At a distance from the die 23, a stripping device 25 is provided which has an opening 26 through which the plunger 24 protrudes. In the region of the opening, the stripping device 25 on the stamp 24th abut or form a small gap to the lateral surface of the punch 24, which is smaller than the wall thickness ei ^¬ nes from the Ronde 10 reshaped container body 27th

Reference to the figures 9 to 11, a Um ^¬ shaping device 22 for performing a reverse extrusion process is exemplified. Alternatively, the method of the present invention may also be used for forming devices 22 that perform a forward extrusion or a combination of backward and forward extrusion.

As schematically illustrated in Figures 9 to 11, the die 23 on the die 24 fed wall ^¬ th page for performing the reverse

Fliespressverfahren open. After inserting the blank 10 into the recess of the die 23, the punch 24 is moved toward the die 23. After contact with the blank 10, the blank is pressed between the die 23 and the punch 24, whereby the material first deformed between the punch 24 and the die 23 and thereby along the punch outer surface of the die 23 out against the direction of movement of the punch 24th flows as illustrated in FIG.

After the end of the forming operation, the punch 24 is moved back away from the die 23. In this reverse movement ^¬ it clips the container body made from 27 at the stripper 25th The container body 27 is then removed from the former 22 and a new blank 10 is inserted into the die 23. The backward extrusion process for producing the container body 27 then begins again.

The invention relates to a process for the preparation a container body. For this purpose, a disc-shaped blank is first ^¬ 10 punched out with a circular cylindrical shape from a metal sheet, in particular an aluminum sheet. Subsequently, the two circular edges 15 of the blank 10 are formed in a compression process in a predetermined desired shape. In this upsetting circumscribed by the two edges 15 peripheral surface 16 of the blank 10 rolls in a the edge shape defining upset groove 19 of a compression tool 18 from. This creates a ge ^¬ genüber a plane of symmetry S, which runs centrally between the two flat sides of the blank 10, symmetric Ge ^¬ Stalt. The blank 10 can be supplied to a forming device 22, therefore without any sorting and Orientie ^¬ tion is required. Thus, the blank 10 with any of its two flat sides 13 a punch 23 and a forming die 24 may be facing. Thus, it is mög ^¬ Lich to feed the blank 10 in two different positions in the forming position P of the forming 22, without in any way adversely affect the forming process or the container body.

Reference sign list:

10 blank, Ronde

11 sheet metal

12 punching tool

13 flat side of the round plate

14 punching burr

15 edge of the round plate

16 peripheral surface

17 compression device

18 compression tool

19 upsetting groove

20 drive board

21 drive groove

22 forming device

23 matrix

24 stamps

25 stripping device

26 opening

27 container body

P forming position

Claims

Claims:

1. A method for producing a container body with the following steps:

Punching out a disc-shaped blank (10) from a metal sheet (11),

- upsetting the two edges (15) of the blank (10),

- Transporting the blank (10) in one

Forming position (P) in a forming device (22) for forming the blank (10) in a container body (27).

2. The method according to claim 1,

characterized in that the blank (10) in the forming position (P) between a punch (24) and a die (23) of the forming device (22)

is arranged.

3. The method according to claim 1 or 2,

characterized in that the blank (10) rests in the forming position (P) with one of its two flat sides (13) on or in the die (24) of the forming device (22).

4. The method according to any one of the preceding claims, characterized in that when upsetting the edges (15) of the blank (10) both edges (15) are processed simultaneously.

5. The method according to any one of the preceding claims, characterized in that the blank (10) during compression of its two edges (15) with its Circumferential surface (16) on a compression tool (18) abwäl ZT.

6. The method according to claim 5,

characterized in that the compression tool (18) has an upsetting groove (19) in which the blank (10) is rolled.

7. The method according to any one of the preceding claims, characterized in that the punching

resulting burr (14) of the blank (10) is removed by the upsetting.

8. The method according to any one of the preceding claims, characterized in that the blank (10) receives by the upsetting one with respect to a median plane (S) between its two flat sides (13) symmetrical shape.

9. The method according to any one of the preceding claims, characterized in that on the blank (10) by the upsetting at its two edges (15) each have a chamfer (F) is formed.

10. The method according to any one of the preceding claims, characterized in that the blank (10) by the upsetting at its two edges (15) each have a ringumlaufender edge (V) is formed.