EP2532454A1 - Method and device for producing multi-wall components - Google Patents

Abstract

The method involves overlapping positions of two sheet material-blanks (3,11), and pressing together the blanks along a closed contour (26) for defining expandable intermediate space between the both blanks. The intermediate space is widened by injecting a pressurized fluid between the mutually compressed blanks. The blanks are fixed along the contour with each other. The width of the intermediate space is maintained at a point (30), when the expansion is zero. An independent claim is included for a device for executing multi-wall components producing method.

Description

The present invention relates to a method and an apparatus for manufacturing multi-layered, in particular clam shell components made of flat material, in particular of sheet metal.

Flat components with high mechanical load capacity are required in agricultural machinery for numerous applications in many different designs. For example, the grain tank cover of a combine harvester, such as in FIG DE 10 2007 003 653 A1 described a variety of large-sized wings, which must have a considerable flexural rigidity so as not to bend under the weight of grain lying thereon. Conventionally used for the construction of such a Korntankdeckels sheets have a thickness of 1 to 2 mm and are additionally provided for stiffening with dotted or glued Hutprofilen. The high weight of these sheets causes high material costs in the production of Korntankdeckels. In field use, the high weight of the grain tank cover increases the fuel consumption of a combine harvester equipped with it and that of its Insert resulting soil compaction. It would therefore be very desirable to be able to produce the wings of such a grain tank lid with the same load capacity with less material.

The same applies to any other plate-shaped components of agricultural machinery, such as body panels, the walls of grain tanks or the like. A particularly great fuel economy can be achieved if it is possible to reduce the weight of plates moved within an agricultural machine, such as vibrating plates, which are used, for example, in a combine harvester for transporting crop material.

Although it is known per se that plates with a multi-shell structure, such as in WO 2005/113230 described achieve a high low weight capacity. However, the use of such multi-shell structured panels in manufacturing is problematic because the finished panels can only be cut to a size required in a particular case with partial destruction of their structure and the finishing of the individual shells in each required for the specific case and the individual dimensions the shells is connected to the finished component with considerable effort. Although it is in principle possible to manufacture these shells, for example by deep drawing, but the high cost of this required for each specific to be manufactured shell mold tools to the fact that this technique is economically only for mass production.

There is therefore a need for a method which enables the production of multi-layer components made of flat material in a simple and flexible manner and is also economical for smaller series, as well as an apparatus for carrying out the method.

• überlappend Platzieren von wenigstens zwei Flachmaterial-Zuschnitten;
• Aneinanderdrücken der zuschnitte entlang einer geschlossenen Kontur, um einen aufweitbaren Zwischenraum zwischen den zwei Zuschnitten zu definieren;
• Aufweiten des Zwischenraums durch Einspeisen eines Druckfluids zwischen die aneinander gedrückten Zuschnitte; und
• Befestigen der Zuschnitte aneinander entlang der Kontur,

zum anderen durch eine Vorrichtung zur Durchführung des Verfahrens mit einem ersten und einem zweiten Werkzeug, die aufeinander zu verschiebbar sind, um wenigstens zwei Flachmaterial-Zuschnitte zwischen den Werkzeugen entlang einer geschlossenen Kontur zu klemmen, und einer Druckfluidquelle zum Einspeisen von Druckfluid in einen von der geschlossenen Kontur begrenzten Zwischenraum zwischen den zwei Zuschnitten.This need is satisfied according to the invention by a method comprising the steps:

• overlapping placing at least two sheet blanks;
• Pressing the blanks together along a closed contour to define an expandable gap between the two blanks;
• Expanding the gap by feeding a pressurized fluid between the blanks pressed together; and
• Attach the blanks together along the contour,

on the other hand by an apparatus for carrying out the method with a first and a second tool, which are mutually displaceable in order to clamp at least two flat material blanks between the tools along a closed contour, and a pressure fluid source for feeding pressurized fluid into one of closed contour limited space between the two blanks.

If at least one of the blanks, where the blanks are not pressed against one another, yields to the pressure of the supplied pressure fluid, it becomes a uniformly curved one in three dimensions, highly-rigid contour deformed. Since used to press the blanks tools only at the points where they actually clamp the blanks must have a defined shape, the tools are simple and inexpensive to implement.

Significant further stiffening of the multi-shell component is achievable if the blanks are further secured together at at least one point within the closed contour.

At this point, a hold-down may conveniently be placed prior to expansion to keep the width of the gap at that point less than around the point.

Preferably, the width of the gap at the point during expansion is kept zero, i. the two blanks are held pressed against each other by the hold-down as well as by the closed contour. However, subsequent attachment of the blanks to each other at the point, in particular by spot welding, is not precluded even if during the flaring it is allowed for the blanks to slightly separate at the point.

Upon expansion, a recess forms on at least one of the blanks around each blank holder, the size of the recess being proportional to the force generated during the expansion of the pressurized fluid to the respective blank holder is exercised. To minimize the risk of damage to the blanks during expansion, the force acting on a single hold down should not be too great. Therefore, it is preferable that, when the blanks are attached to each other at a plurality of points of the closed contour, the areas of the recesses formed upon widening around each of these points are higher by a factor of 2, and even better by a factor of at most one , 25 different.

If one of the blanks has an edge projecting beyond the closed contour, then it is expedient to turn over this protruding edge in order to form a groove extending around the edge of the other blank. This turnover of the edge may be sufficient to secure the blanks together along the contour. Preferably, however, the folding occurs in addition to welding or bonding the blanks together along the contour.

Welding may be performed after folding to secure the other blank on both sides between the first blank and its folded edge; However, it is also conceivable to turn over the edge only after the welding or gluing in order to mask sweat marks.

The blanks can be placed between a first and a second tool and then the tools are moved towards each other to press the blanks together.

A first tool, on which one of the blanks is placed adjacent, is preferably flat at least along the closed contour and within it, so that the blank attached to it remains flat during the expansion and only the other blank facing the second tool is deformed.

The closed contour is preferably removably mounted to the second tool for preparation of the method described above. By replacing the closed contour, the tools can be adapted in a short time for the production of different types of components. This allows a good utilization of the tools even when manufacturing numerous small series of components.

The hold-downs are preferably variably mounted on the second tool.

Fig. 1

eine schematische perspektivische Ansicht eines ersten Werkzeugs einer erfindungsgemäßen Vorrichtung zum Fertigen von mehrschaligen Bauteilen aus Flachmaterial;

Fig. 2

ein vergrößertes Detail des ersten Werkzeugs und daran platzierter Blechzuschnitte;

Fig. 3

eine schematische perspektivische Ansicht eines zweiten Werkzeugs der Vorrichtung;

Fig. 4

einen schematischen Querschnitt durch zwei zwischen den Werkzeuge platzierte Blechzuschnitte vor dem Aufweiten;

Fig. 5

einen zu Fig. 4 analogen Querschnitt nach dem Aufweiten;

Fig. 6

eine Draufsicht auf ein fertiges Bauteil;

Fig. 7

einen Querschnitt durch ein fast fertiges Bauteil gemäß einer ersten Abwandlung der Erfindung;

Fig. 8

einen zu Fig. 7 analogen Querschnitt durch ein fertiges Bauteil gemäß einer zweiten Abwandlung der Erfindung; und

Fig. 9

einen zu Fig. 4 analogen Schnitt gemäß einer dritten Abwandlung der Erfindung.

Further features and advantages of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying figures. Show it:

Fig. 1

a schematic perspective view of a first tool of a device according to the invention for the manufacture of multi-layered components made of flat material;

Fig. 2

an enlarged detail of the first tool and sheet metal blanks placed thereon;

Fig. 3

a schematic perspective view of a second tool of the device;

Fig. 4

a schematic cross section through two placed between the tools blanks before expansion;

Fig. 5

one too Fig. 4 analogous cross-section after expansion;

Fig. 6

a plan view of a finished component;

Fig. 7

a cross-section through an almost finished component according to a first modification of the invention;

Fig. 8

one too Fig. 7 analogous cross section through a finished component according to a second modification of the invention; and

Fig. 9

one too Fig. 4 analogous section according to a third modification of the invention.

This in Fig. 1 The first tool shown essentially comprises a rigid plate 1 with a flat working surface 2, on which a first blank 3 made of sheet metal, preferably of 0.4 to 0.5 mm thickness, is arranged for processing. If the first tool with upside down working surface 2, in the in Fig. 1 shown perspective, the blank 3 can rest loosely on the plate 1; otherwise, a temporary fixation of the blank 3 to the plate 1, for example by acting on its edge, in the figure Claws, not shown, by magnets, distributed over the working surface 2 suction nozzles or the like appropriate. The blank 3 is shown here by way of example as a rectangle, but it is obvious that the blank 3 can have largely arbitrary shapes.

A compressed air outlet 4 is arranged on an edge of the working surface 2. Fig. 2 shows the compressed air outlet 4 in an enlarged view. A block-shaped main body 5 of the compressed air outlet is detachably attached to the working surface 2, for example by means of screws 6. A compressed air hose 7 is connected to a side of the main body 5 facing the edge of the working surface 2, and a bore extends from the connection point of the hose 7 through the main body 5 to the tip of a tongue 8, whose flat underside 9 rests flat on the blank 3 and the top 10 has a gently wavy curved course.

A second sheet metal blank 11, of which in Fig. 2 According to a first embodiment of the invention, a fragment is substantially congruent with the blank 3. Above the tongue 8, the blank 11 is provided with a slot 12 which, when the blanks 3, 11 are correctly placed on top of each other, at a crest line 13 of the top 10 of the tongue 8 comes to rest. The slot 12 bifurcates at its inner end into two branches 14. The branches 14 bound together a triangular projection 15 of the blank 11, the free tip on the crest line 13 to lie comes, and in each case together with the slot 12, two trapezoidal tabs 16 which are each bent upward along dotted lines 17 to receive the tongue 8 when the blank 11 is pressed against the tongue 8 and the blank 3.

A second tool, which serves together with the plate 1 for compressing the blanks 3, 11, is in Fig. 3 in one too Fig. 1 shown analog perspective view. The second tool also includes a solid steel plate 18 on which a plurality of elongate and angular webs 19, 21 and downers 22 are mounted. To attach the components mentioned z. B. angular clamps serve 23, of which in Fig. 3 for clarity, only a few are shown. The clamping claws 23 each have a slot through which a screw 24 extends. The screws 24 each engage in not visible in the figure threaded rods, which are slidably received in T-slots 25 of the plate 18. The webs 19, 21 and hold-down 22 each have a T-shaped cross section, wherein a crossbar of the T is kept pressed by the clamps 23 against the plate 18 and a foot of the T protrudes from the plate 18. As can easily be seen, in this way the components 19, 21, 22 can be fixed in substantially arbitrary positions on the plate 18.

In the presentation of the Fig. 3 are two elongated webs 19 and angular webs 21 mounted on the plate 18 so that their end faces touching each other and connect their facing away from the plate 18 apex surfaces 26 continuously to each other. Two further elongate webs 19, 20 and an angular web 21 are each shown floating over their intended mounting positions. The profile element 20 differs from the profile elements 19 only by a recess 27 in its apex surface 26, which is complementary to the top 10 of the tongue 8 is formed. It is easily conceivable that when these webs as well as four further elongate webs 19 and an angular web 21 are mounted along the track defined by dotted lines on the plate 18, their vertex surfaces 26 form a closed rectangular contour extending around the blank holders 22 ,

Other contours can be realized without difficulty, if the number of webs used 19, 20, 21 is varied or if necessary, in addition to the webs shown also arcuate webs are used.

Fig. 4 shows a schematic cross section through the two blanks 3, 11, which are superimposed and clamped between the plate 1 and mounted on the plate 18 webs 19, 20, 21 and hold down 22. The compressed air outlet 4 and to its tongue 8 complementary recess 27 of the web 20 are outside the cutting plane of the Fig. 4 in that one of the lugs 16 bent upwards on the tongue 8 is visible on the flank of the tongue 8. The closed contour formed by the apex surfaces 26 of the webs 19, 20 21 holds the edges 28, 29 of the blanks 3, 11 pressed firmly and substantially airtight to each other. Accordingly, the hold-down members 22 cylindrical in axial cross-section hold the blanks 3, 11 pressed against each other at points 30.

While the blanks 3, 11 are held pressed against each other, compressed air is fed via the outlet 4 between the blanks 3, 11. Since the blank 3 rests flat on the plate 1, it can not escape the pressure and remains flat. The blank 11, however, forms, as in Fig. 5 to see in each space between the elements 19, 20, 21, 22 in cross-section of an arc. Since the shape of this arc is not specified by contact with a molding tool away from the apex surfaces 26 of the webs and hold-downs, the contour which sets itself with the least possible expenditure of force and, consequently, also with the smallest possible arrangement of the apex surfaces 26 possible stress of the blank 11 can be realized. The strain hardening associated with the deformation of the blank 11 limits the amount of deflection of the blank 11 in the immediate vicinity of the apexes 26 and prevents the formation of kinks at which the blank 11 could possibly rupture.

Fig. 6 showed a plan view of the blank 11 after expansion. Along the edge 29 and at the points 30, the blank 11 has not been deflected and continues to touch the blank 3 there. The blank 11 is located everywhere in between splayed from the blank 3. Dotted lines 31 each indicate apex lines from which the surface of the blank 11 drops in opposite directions. These lines 31 divide the blank 11 into a zone 32 sloping towards the edge 28 and five recesses 33 surrounding the points 30. The tensile load to which the blank 11 in the vicinity of each point 30 is subjected during expansion is proportional to the areal extent of the respective zone Point 30 surrounding recess 33. To minimize the risk of damage to the blank 11 during expansion, the points 30 are placed so that the surfaces of the surrounding recesses 33 are substantially equal in size.

The two blanks 3, 11 are fastened to each other after deformation. In the simplest case, if the two blanks 3, 11 are exactly congruent, this can be done by attaching spot welds 34 at the points 30 as well as along the edges 28, 29.

Fig. 7 shows a partial cross section through the attached blanks 3, 11 according to a further development of the invention. The edge length of the blank 11 is here slightly larger than that of the blank 3, so that the edge 29 protrudes slightly. After the edges 28, 29 as in the Fig. 7 shown by spot welds 34 have been attached to each other, the protruding portion of the edge 29 can be bent hairpin-shaped as indicated by an arrow around the edge 28 of the blank 3 to clamp this form-fitting. Welding marks on the edge 28 can be obscured by this, which is particularly advantageous when the cut blank 3 is to form a visible side of the finished component.

The bending of the protruding edge 29 may even make a weld along the edges 28, 29 under certain circumstances superfluous.

Of course, according to a second development, the blank 3 may also have the larger edge length and an overhanging portion of its edge 28 may be bent to clamp the edge 29 of the deformed blank 3, as in FIG Fig. 8 shown.

Fig. 9 shows you one Fig. 5 analog section through the blanks 3, 11 inserted between the plates 1, 18 of the processing device according to this second development. The plate 1 is provided with a flachbödigen recess 35 whose outline corresponds to the formed by the apex surfaces 26 of the webs 19, 20, 21 closed contour. At the edges of the recess 35 on the surface 2 of the plate 1 isolated projections 36 are arranged, one of which is formed by the main body 5 of the compressed air outlet. As in Fig. 9 to see the blank 11 would fit into the recess 35, but the edge 28 of the blank 3 is located around the recess 35 on the surface 2 on. The edge 28 is provided in places with cutouts for receiving the projections 36. In Fig. 2 is such on the recess 35 projecting portion of the edge 28 and a cutout 37 formed therein for receiving the base body 5 with shown dashed lines. The projections 36 give the position in which the blanks 3, 11 can be placed on the plate 1 exactly. When the plates 1, 18 are pressed against each other, the blanks 3, 11 are pressed into the recess 35, whereby the protruding portion of the edge 28 is angled and the outside of the webs 19, 20, 21 applies. This simplifies the subsequent bending of the edge 28 to the in Fig. 8 shown hairpin contour.

The blanks 3, 11 are shown in the figures for the sake of simplicity as rectangles; Blanks in this form are suitable, for example, to the wings of a folding Korntankdeckels from DE 10 2007 003 653 A1 known type to form. Body panels of a combine harvester can have more complex shapes, but it is obvious that these too can be processed by means of the profile elements 19, 20, 21 which can be mounted on the plate 18 in a largely arbitrary arrangement. For example, a sheet metal part, also referred to as sliding protection, which forms a wall between the cleaning fan and the wheel arch of a combine harvester, has the shape of a rectangle with a semi-circle attached to a narrow side. Also, such a part is conveniently and economically manufacturable by the above-described technique by circular arc-shaped profile elements are mounted on the plate 18 instead of the rectilinear profile elements 19, 20, 21 shown in the figures for its semicircular edge.

reference numeral

1

plate

2

work surface

3

cut

4

Pressluftauslass

5

body

6

screw

7

Compressed air hose

6

tongue

9

bottom

10

top

11

cut

12

slot

13

crest line

14

branch

15

head Start

16

flap

17

lines

18

plate

19

profile element

20

profile element

21

elbows

22

Stripper plate

23

Spannspratzen

24

screw

25

T-slot

26

apex surface

27

recess

28

edge

29

edge

30

Point

31

line

32

Zone

33

deepening

34

spot welding

35

recess

36

head Start

37

neckline

Claims (15)

Method for manufacturing multi-layered components from flat material with the steps; - overlapping placing at least two flat material blanks (3, 11); Pressing the blanks (3, 11) along a closed contour (26) to define an expandable space between the two blanks (3, 11); - widening the gap by feeding a pressurized fluid between the pressed blanks (3, 11); - Attaching the blanks (3, 11) to each other along the contour (26). Method according to claim 1, with the additional step: - Attaching the blanks (3, 11) to each other at at least one point (30) within the closed contour (26). A method according to claim 2, characterized in that prior to expansion at the at least one point (30), a hold-down (22) is placed to keep the width of the gap at the point (30) less than around the point (30). , A method according to claim 3, characterized in that the width of the gap is kept at zero at point (30) during expansion. Method according to one of claims 2 to 4, characterized in that the blanks (3, 11) are fastened to each other at a plurality of points (30) within the closed contour (26), wherein when widening around each point (30) a recess (33 ) and the areas over which the depressions (33) extend differ by at most a factor of 2, preferably at most by a factor of 1.25. Method according to one of the preceding claims, characterized in that the blanks (3, 11) are secured to each other by welding, in particular spot welding (34), or gluing. Method according to one of the preceding claims, comprising the further step of turning over one edge (28, 29) of one of the blanks (3, 11) projecting beyond the closed contour, around one edge (29, 28) of the other blank (11, 3) ) to form a circumferential groove. Method according to one of the preceding claims, characterized in that the blanks (3, 11) placed between a first and a second tool (1, 18) and the tools (1, 18) to each other to be moved to press the blanks (3; 11) together. A method according to claim 8, characterized in that one of the blanks (3) is placed adjacent to a surface (2; 35) of the first tool (1) which is planar at least along and within the closed contour (26). A method according to claim 8 or 9, characterized in that the closed contour (26) is mounted in advance removably on the second tool (18). A method according to claim 8, 9 or 10, characterized in that the closed contour (26) from a plurality of webs (19, 20, 21) is joined together. Method according to one of claims 8 to 11, as far as dependent on claim 3, characterized in that the at least one hold-down device (22) is detachably mounted in advance on the second tool (18). Device for carrying out the method according to one of the preceding claims, comprising a first and a second tool (1, 18) which are displaceable towards each other, along at least two flat material blanks (3, 11) between the tools (1, 18) a closed contour (26) to clamp, and a source of pressurized fluid (4) for feeding pressurized fluid into an intermediate space defined by the closed contour (26) between the two blanks (3, 11). Apparatus according to claim 13, characterized in that the closed contour (26) by on the second tool (18) variably mountable webs (19, 20, 21) is defined. Apparatus according to claim 12 or 13, characterized by on the second tool (18) variably mountable hold-down (22).

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