EP2802425B1 - Device and method for the deep drawing of shell parts with integrated head and frame trimming - Google Patents

Description

The invention relates to a device for producing shell parts having at least one bottom, a frame and optionally a flange portion of a flat or preformed board with a drawing die and a drawing die, wherein the drawing die has a molding area and at least one trim area, wherein the molding area of Drawing die at the completion of the drawing operation, the outer shape of the drawn and to be cut shell part in the bottom, Zargen- and optionally in the flange region, the drawing die has a molding area and at least one trim area, wherein the forming region of the drawing die at the completion of the drawing process, the inner shape of the drawing and has to be cut shell part with bottom, frame and optional flange area. In addition, the invention relates to a method for the production of shell parts.

Such a device and such a method are eg in the WO-A-2008025387 disclosed.

Shell parts having a bottom portion, a frame portion, and optionally a flange portion are often made by drawing a flat or preformed metal sheet, preferably steel. The prior art discloses methods and devices for producing, in particular, flange-type drawn parts with which drawing parts can be produced from a flat board by deep-drawing and trimming in one working stroke. So is from the textbook " Cutting, punching and Drawing tools ", Öhler and Kaiser, 8th edition (2001 ) known to execute the drawing die, which comprises the bottom portion, frame portion and flange portion of the drawn part, height-displaceable in order to cut the finished drawn part on the flange outside of the driven together tool parts (die and punch) after the performed drawing process, so that in the result the desired , Flange-prone drawing part can be manufactured in a working stroke of the drawing punch. A corresponding drawing die is shown on page 429 in the cited textbook. Due to the height-adjustable drawing die, however, the structure of the known from the prior art cutting-tensile tool is relatively complex.

Furthermore, there are already in the prior art methods and corresponding devices for the production of drawn parts with integrated trimming, which perform to avoid scraping the flange on the cutting edge of the drawing die the cutting process in a stretch-drawing step of the board, so that during the cutting process, the material under heavy tensile load stands and the flange area runs after the cut accordingly. Due to the relatively uncontrolled trailing of the flange so drawn parts can not be made dimensionally accurate with high process reliability. Finally, another problem is that the flange area must additionally extend obliquely to the frame area in order to avoid scraping on the sharp cutting edge. An often desired right-angled course of the flange area to the frame area can not be produced in one method step. Deep-drawing presses do not have a high-precision tool guide, so that trimming operations, especially in the area of the bottom and frame area in Such presses are not possible or can only be carried out very difficult and expensive.

With the not yet published German patent application DE 10 2011 050 002.2 Although the applicant has achieved a solution for trimming the flange area in one step during the drawing. However, there is a similar problem for the Kopfbeschnitt a drawn board. So far, at least two process steps are used, namely pulling the board and performing the cut. If, in addition, a so-called head trimming in the base and frame region and possibly in the flange region of a shell part, additional cutting steps are usually required.

On this basis, the present invention seeks to provide an apparatus and a method for the production of shell parts by deep drawing available with which or with which with as few steps, the production of the shell part and at the same time a dimensionally accurate trim at least in Zargen- and Floor area of the shell part can be achieved.

The above object is achieved according to the teaching of the present invention with a device having the features of the preamble of claim 1, characterized in that the trimming portion of the drawing punch forms a cutting contour with the forming region of the drawing die, with which a separation of the trimming during and at the completion of the drawing process - And shape of the board at least in Zargen- and bottom portion of the finished molded shell part preferably in the last drawing operation is feasible.

By providing the cutting contour between the cutting area of the drawing die and the forming area of the drawing die is achieved that when inserting the drawing die in the drawing die inserted in the drawing die board first in the frame area engages the cutting contour and the finished shell part with completion of the drawing process in Floor area can be separated. In the preferably last drawing process, therefore, a finished, drawn shell part can be produced with bottom and Zanzgenbeschnitt. The shaping region of the drawing punch or of the drawing die forms the region which leads to the transformation of the essentially planar blank or also preformed blank to the finished shell part. The trimming area serves to provide material for a defect-free drawing operation, so that an e.g. wrinkle-free pulling the molding area of the board is guaranteed. By separating the Zargen- and bottom portion of the finished shell part of the trimming area of the board, a finished shaped and trimmed shell part can be prepared in a preferably last drawing operation.

According to a first embodiment of the device according to the invention, the forming area of the drawing punch is recessed in comparison with the trimming area of the drawing punch, and the forming area of the drawing die is increased in comparison to the trimming area of the drawing die. Preferably, the height difference between the trimming and shaping area corresponds at least to the wall thickness of the board to be reshaped. Due to the fact that the forming area of the drawing punch is recessed in comparison to the trimming area of the drawing punch, a normal drawing operation is achieved, as this does not cause any additional material in the bottom area of the board is required due to the greater draw depth of the trim area of the drawing punch. In addition, the height difference between the forming and trimming areas allows dimensionally accurate and complete separation of the finished shell part during and at the completion of the drawing operation. It is also conceivable that the trimming area of the drawing punch is increased and the forming area of the drawing die is formed recessed or a combination of recessed and raised areas, for example the trimming area of the drawing punch with corresponding raised and recessed forming areas in the drawing die is used.

If the cutting contour of the drawing die or the drawing die runs through the frame, bottom and optionally the flange region of the half-shell, the shell part can be completely cut free from the formed blank during the drawing process. This makes it possible, as in a conventional deep-drawing process, for example, to provide additional material in the flange region, which material can flow in during the drawing process in order to specifically shape the flange region. Excess material can then be removed via the cutting contour of the shell part, so that high-dimensional edge regions of the shell part can also be provided, for example, in the flange area.

In order to lower the cutting forces which occur during the drawing process, according to a further embodiment of the device, the cutting contour between the cutting area of the drawing punch and the forming area of the drawing die in the bottom area and optionally in the flange area Lengthwise varying engagement heights on. The varying engagement heights ensure that, during the retraction of the draw punch into the draw die, the engaged die portions of the die and die sink engage different depths of insertion of the draw die just prior to completion of the draw operation and thus a continuous separation process along the cutting contour. which begins point or area, is guaranteed. By not simultaneously separating the molding area and the cutting area of the drawn board along the entire length of the cutting contour, it is ensured that the cutting forces remain moderate and the "cutting stroke" known in the art can be substantially prevented.

Preferably, the various engagement heights between the molding area and the trimming area of the drawing die and / or the drawing die are provided by a designated inlet contour. The inlet contour can have different shapes. Thus, it is possible, for example, to ensure different engagement heights by means of a linear inlet contour, which has inclinations varying in the cutting contour direction.

According to a further embodiment of the device according to the invention a round inlet contour is at least partially provided in areas of the cutting contour of the drawing punch in which a cutting edge is arranged in the corresponding region of the drawing die and / or in the drawing punch at least partially a cutting edge in the areas of the cutting contour of the drawing die provided in which a round inlet contour is provided in the drawing die. Through the combination of round inlet contour, ie the inlet contour has a radius instead of a "sharp" cutting edge, and "sharp" cutting edge can be done simultaneously during the drawing process with the initiation of the cutting process, an improved centering of the drawing die in the drawing die. This results in a particularly accurate cut. It is also conceivable to use two striking "sharp" cutting edges.

Preferably, at least the cutting contour forming parts of the drawing punch and / or the drawing die are designed as exchangeable inserts, since they are subjected to increased wear and can then be easily replaced.

According to a further embodiment of the device optionally a planar board support area is provided, so that the board can be inserted in a simple manner prior to forming and trimming, for example automatically, in the device.

According to a next embodiment of the device, particularly good cutting results could be achieved in that the inlet contour has at least a radius of 0.5 mm and the cutting edge has a radius of not more than 0.05 mm, in particular not more than 0.02 mm. As a result, a particularly good centering of the drawing punch when pulling and trimming the board is achieved, so that a very good dimensional stability can be guaranteed.

Finally, during the drawing process, the flow of material can be additionally controlled by providing a hold-down device for holding down the sheet to be pulled during drawing.

According to a next teaching of the present invention, the object is achieved by a method for producing shell parts with a bottom, frame and optionally a flange portion of a flat or preformed circuit board by pulling using the device according to the invention, wherein a metal circuit board, preferably steel, is inserted into the device and pulled by retraction of the drawing die in the drawing die the board and is trimmed during the forming process at least in the bottom and Zargenbereich by the provided cutting contour, so that a trimming area and a molding area of the board is at least partially separated and a finished shell part, which has substantially the shape of the molding area of the drawing die and the drawing die, is produced. As already explained above, it is achieved by the method according to the invention using the device according to the invention that a shell part can preferably be produced from a flat or preformed board in a last drawing operation, which is simultaneously trimmed at least in the bottom and frame region. With the method according to the invention shell parts can be produced in a particularly economical manner.

According to one embodiment of the method, this is formed by the forming region of the drawing punch and the drawing die Shell part with completion of the drawing process completely separated from the trim area.

Alternatively, it is also possible according to a further embodiment of the method, along the cutting line partially material, preferably in the form of webs, to stand, i. to produce an interrupted cut line, whereby the shell part is at least partially still connected to the trim area and at the same time can be removed from the tool. In a further separation process, the cut area can then be separated from the good part.

In order to keep the cutting forces moderate during trimming of the board and to substantially prevent the so-called "chipping", the trimming of the board in the ground and optionally in the flange area is preferably carried out at least partially continuously starting from the first engaged areas of the cutting contour between the molding area and trimming area of the drawing punch and drawing die. Due to the fact that not the complete cutting contour is engaged at a certain depth of insertion of the drawing punch, it is possible to achieve a continuous trimming of the board during the drawing process or at the completion of the drawing process.

Finally, it is particularly advantageous for steel blanks when these blanks are hot worked. In a hot forming of a steel plate, the board is preferably heated to a temperature above the AC3 temperature point, hot formed, so that there is a more easily formed structure in the board. Will the board in the closed state of the tool quenched, a press hardening can be achieved if the material of the board allows a transformation into a substantially martensitic structure.

Fig. 1a)

in einer perspektivischen Darstellung ein typisches Schalenteil, welches mit der erfindungsgemäßen Vorrichtung hergestellt werden soll,

Fig. 1b)

eine schematische Draufsicht auf eine umzuformende Platine vor dem Ziehen und Beschneiden,

Fig. 2 bis 4

in einer schematischen Schnittansicht entlang der Schnittlinie S in Fig. 1a) ein Ausführungsbeispiel einer Vorrichtung mit eingelegter Platine während verschiedener Zeitpunkte des Ziehvorganges,

Fig. 5 und 6

in einer perspektivischen Darstellung ein Ausführungsbeispiel einer tiefgezogenen und geschnittenen Platine zu verschiedenen Zeitpunkten des Ziehvorganges,

Fig. 7

in einer perspektivischen Darstellung das Ziehgesenk des Ausführungsbeispiels aus Fig. 2 bis 6,

Fig. 8

in einer perspektivischen Darstellung den Ziehstempel des Ausführungsbeispiels aus Fig. 2 bis 6 und

Fig. 9

schematisch einen beispielhaften Verlauf der Eingriffshöhe entlang der Schneidkontur im Boden- und optional im Flanschbereich.

In addition, the invention will be explained in more detail with reference to embodiments in conjunction with the drawings. The drawing shows in

Fig. 1a)

in a perspective view of a typical shell part, which is to be produced with the device according to the invention,

Fig. 1b)

a schematic plan view of a reshaped board before pulling and trimming,

Fig. 2 to 4

in a schematic sectional view along the section line S in Fig. 1a ) an embodiment of a device with inserted board during different times of the drawing process,

FIGS. 5 and 6

in a perspective view of an embodiment of a deep-drawn and cut board at different times of the drawing process,

Fig. 7

in a perspective view of the drawing die of the embodiment Fig. 2 to 6 .

Fig. 8

in a perspective view of the drawing punch of the embodiment Fig. 2 to 6 and

Fig. 9

schematically an exemplary profile of the engagement height along the cutting contour in the ground and optionally in the flange area.

First shows Fig. 1a ) A shell part 1 with a bottom portion 2, a frame portion 3 and a flange 4. A corresponding shell part 1 can be used for example for producing a support of a motor vehicle, wherein the shell part 1, for example, connected to a further shell part on the flanges 4 and can form a stable hollow body. Further shows Fig. 1a ) a section line S, which indicates the section line in which the Fig. 2 to 4 are shown.

Starting material, for example, in Fig. 1b ) in a schematic plan view shown board 5, which has a trimming area 5a and a molding area 5b, wherein in the present embodiment, the trimming area 5a is arranged circumferentially around the molding area 5b. The trimming area 5a forms the area of the board, which after forming and trimming is no longer part of the finished shell part 1. Corresponding trim and shaping areas are also provided in the device for producing the shell parts in order to differently shape and separate the different areas.

An embodiment of an apparatus for producing a shell part 1 from a board 5 along the section line S is shown in FIG Fig. 2 shown. Fig. 2 shows a planar board 5, which is inserted into a drawing die 6. The drawing punch 7 comprises two hold-downs 7a, with which the material feeder can be controlled when pulling. In addition, the drawing punch 7 has a trimming area 8 and a forming area 9. The drawing die 6 also has a trimming area 8 'and a forming area 9'. The molding area 9 of the drawing punch 7 has the inner mold 10 (FIG. Fig. 1 ) of the shell part and the mold portion 9 'of the drawing die 6, the outer mold 11 of the finished shell part 1. The trimming area 8 of the drawing punch 7 forms, with the forming area 9 'of the drawing die, a cutting contour 12 which makes it possible to separate the forming area 5b of the formed blank 5 and thus the shell part 1 from the trimming area 5a of the board 5 at least in the bottom area 2 and in the frame area 4 , The separation takes place during the drawing process, as in the Fig. 3 and 4 will be shown. The cutting contour 12 is preferably provided by inserts 7b, 6a both in the drawing punch 7 and also in the drawing die 6 in order to be able to carry out a simple replacement when worn.

As in Fig. 3 First, the drawing punch 7 dips into the drawing die 6 and deforms the blank 5 with the protruding cutting area 8 in such a way that the blank is drawn without folds in the forming area 9 or 9 'of the drawing die 6 or of the drawing die 7. This is ensured, for example, by the fact that, as in the present embodiment of the Fig. 3 and 4 illustrated, the forming portion 9 of the drawing die is formed recessed relative to the trimming portion 8 of the drawing die, wherein the height difference a between the trimming area and the forming area of the drawing punch is at least the wall thickness of the board. As in Fig. 3 Also shown, the forming area 9 'of the drawing die has an inlet rounding 13 at the transition to the cutting area 8'. This inlet rounding 13, together with the cutting edge 14 provided in the drawing punch during the transition from the shaping area 9 into the trimming area 8, improves the centering of the drawing punch without expensive guiding measures. If the drawing punch 7 now penetrates even deeper into the drawing die 6 and reaches its end position, the shell part 1 is separated in the forming area from the cutting area 15 of the formed blank via the cutting edge 14 and the inlet rounding 13, so that the cutting line through the frame area 3 and the Floor area 2 of the shell part 1 extends. Preferably, the trimming area 8 of the drawing punch 7 or the trimming area 8 'of the drawing die 6 also runs circumferentially around the flange area 4 of the finished shell part 1, so that the edges of the flange area 4 are trimmed during the drawing process and thus free from influences of the drawing process.

The Fig. 5 and 6 show in a perspective view of the drawing and cutting process on a formed board 5, which has a trimming area 5a and a molding area 5b. As in Fig. 5 During the pulling process, the shell part 1 or the forming area 5a of the board is completely separated out until the completion of the drawing process, during the drawing process, the cutting process begins on the frame 3 of the later shell part 1. Fig. 6 , The trimming is preferably carried out both in the frame area 3 and in the floor area 2. In the illustrated Embodiment additionally, the flange 4 is cut free at the end of the drawing process.

Fig. 7 and Fig. 8 show an embodiment of the drawing punch 7 and the drawing die 6 in a perspective view. In Fig. 7 It can be clearly seen that the molding area 9 'in the drawing die is raised in relation to the immediately adjacent cutting area 8'. In return, in the drawing stamp 7, which in Fig. 8 is shown, the molding area 9 formed recessed relative to the immediately adjacent Beschnittbereich 8. This ensures that over the projecting areas of the trimming area 8 of the drawing punch 7, the board can be pulled wrinkle-free and without damage by the "sharp" edges of the tool to then the shape of the molding area 9 'or 9 of the drawing die 6 respectively of the drawing punch. 7 to accept. At the same time, the shell part 1 is completely trimmed over the cutting contour 12 of the drawing punch 7 or cutting contour 12 'of the drawing die 6. In the Zargenbereich it comes to a complete overlap of the cut edges of the drawing punch 7 and the drawing die. 6

In Fig. 9 is now shown schematically the cutting contour 12 of the drawing punch 7 for the bottom and possibly flange area. The engagement height 16, ie the height at which the drawing punch 7 and the drawing die 6 engage and cut the board 5, is shown as a section line 16. The section line 16 shows a varying height, so that the cutting process begins first in the areas 16a and continues with increasing depth of insertion of the drawing punch in the arrow direction. As a result, the cutting forces can be kept moderate. For the course of the Engagement line 7 of the cutting contour 12 are different forms conceivable, for example, a linear, a wavy or, for example, a sawtooth course.

In the illustrated embodiment, the drawing punch 7 is provided with a recessed molding area 9. The drawing die 6 of the embodiment has an elevated molding area 9 '. It is also conceivable, however, as already stated, that the drawing die 6 has a recessed molding area and the drawing punch 7 has a protruding molding area or a combination of both is provided.

By using the device according to the invention, as already explained, a flat or, for example, preformed board 5 can be formed into a shell part 1 with an optional flange area 4 in a last drawing operation and at the same time be cut to size. The typical Kopfbeschnitt the drawn parts, which usually takes place in several steps, is then no longer necessary. The production of shell parts 1 can be made significantly more economical.

Claims (13)

1. Device for producing shell components (1) having at least a lower region (2), a frame region (3) and optionally a flange region (4) from a planar or preformed plate (5) with a drawing die (6) and a drawing punch (7), the drawing die (6) having a shaping region (9') and at least one cutting region (8'), the shaping region (9') of the drawing die (6) having at the end of the drawing operation the outer shape (11) of the shell component (1) to be drawn and to be cut in the lower region (2), frame region (3) and optionally in the flange region (4), the drawing punch (7) having a shaping region (9) and at least one cutting region (8), the shaping region (9) of the drawing punch (7) having, at the end of the drawing operation, the inner shape (10) of the shell component (1) to be drawn and to be cut with a lower region, frame region and optionally a flange region (2, 3, 4),
   characterised in that
   the cutting region (8) of the drawing punch (7) forms with the shaping region (9') of the drawing die (6) a cutting contour (12) with which, during and at the end of the drawing operation, a separation of the cutting region and shaping region (5a, 5b) of the plate (5) can be carried out at least in the frame region, lower region (2, 3) and optionally in the flange region (4) of the completely formed shell component (2), preferably in the final drawing operation.
2. Device according to claim 1,
   characterised in that
   the shaping region (9) of the drawing punch (7) is constructed so as to be recessed in comparison with the cutting region (8) of the drawing punch (7) and the shaping region (9') of the drawing die (6) is constructed so as to be raised in comparison with the cutting region (8') of the drawing die (6).
3. Device according to claim 1 or 2,
   characterised in that
   the cutting contour extends through the frame region, lower region and flange region (2, 3,4) of the shell component (1).
4. Device according to any one of claims 1 to 3,
   characterised in that
   the cutting contour (12) between the cutting region (8) of the drawing punch (7) and the shaping region (9') of the drawing die (6) has engagement depths (16) which vary in a longitudinal direction in the lower region and optionally in the flange region (3, 4).
5. Device according to any one of claims 1 to 4,
   characterised in that
   an introduction contour (13,14) is provided between the shaping region (9,9') and the cutting region (8,8') of the drawing punch (7) and/or the drawing die (6).
6. Device according to any one of claims 1 to 5,
   characterised in that
   a round introduction contour is provided in the drawing punch (7) at least partially in regions of the cutting contour (12) of the drawing punch (7), in which regions a cutting edge is arranged in the corresponding region of the drawing die (6) and/or a cutting edge (14) is provided at least partially in the drawing punch (7) in the regions of the cutting contour (12) of the drawing die (6), in which regions a round introduction contour (13) is provided in the drawing die (6).
7. Device according to any one of claims 1 to 6,
   characterised in that
   the portions of the drawing punch (7) and/or the drawing die (6) forming the cutting contour (12) are in the form of exchangeable inserts (7b, 6a).
8. Device according to any one of claims 1 to 7,
   characterised in that
   the introduction contour (13) has at least a radius of 0.5 mm and the cutting edge (14) has a radius of a maximum of 0.05 mm.
9. Device according to any one of claims 1 to 8,
   characterised in that
   a retention member (7a) is provided for retaining the plate (5) to be drawn during the drawing operation.
10. Method for producing shell components having a lower region, frame region and an optional flange region from a planar or preformed plate by drawing using a device according to any one of claims 1 to 9, wherein the plate is inserted into the device and the plate is drawn by introducing the drawing punch into the drawing die and is cut by the provided cutting contour during the shaping operation at least in the lower region and frame region so that a cutting region and a shaping region of the plate is at least partially separated and a finished shell component which substantially has the shape of the shaping region of the drawing punch and the drawing die is produced.
11. Method according to claim 10,
    characterised in that
    the shell component drawn by the shaping region of the drawing punch and the drawing die is completely separated from the cutting region of the plate when the drawing operation is finished.
12. Method according to claim 10 or 11,
    characterised in that
    the cutting of the plate is carried out in the lower region and optionally in the flange region at least partially continuously beginning from the regions of the cutting contour initially in engagement between the shaping region and the cutting region of the drawing punch and the drawing die.
13. Method according to claims 10 to 12, characterised in that the plate is shaped in the hot state.

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