DE102009053365A1 - Complex and pre-finished sheet metal shaped part i.e. motor vehicle body part, producing method, involves shaping surface section of blank and inhibiting continued flow of sheet metal material to edge-close section - Google Patents

Abstract

The method involves providing a starting blank formed of sheet metal material. The blank is placed in a forming tool and the forming tool is closed, where clamping of the starting blank takes place in an edge-close section (28). Flange sections (21, 22) of the blank are bent, where the flange sections lie in an outward manner with respect to the edge-close section. A surface section (27) of the blank is shaped, where the surface section lies in an inward manner with respect to the edge-close section. Continued flow of the sheet metal material to the edge-close section is inhibited. An independent claim is also included for a forming tool for producing a complex and pre-finished sheet metal shaped part.

Description

The invention relates to a method for producing a complex and substantially ready for molding ready-to-use sheet metal part. The invention further relates to a forming tool which is suitable for carrying out this method.

A complex sheet-metal shaped part is understood to be a component formed from a sheet metal material, which has a complex shape, which in particular also includes free-form surfaces. Such sheet metal parts are z. B. body parts for motor vehicles. According to the current industrial state of the art, the production of complex sheet metal parts is carried out in a drawing process (eg deep drawing process) by means of a tool set comprising a plurality of tools which carry out various forming operations and cutting operations. Due to the process, the output board for the shaping is oversized with respect to a flat development of the sheet metal part geometry. The trimming of the sheet metal part is usually done after completion of the molding, wherein the cut sheet metal material is obtained as metal scrap.

The invention has for its object to further develop a conventional method for producing a complex sheet metal part to the effect that the smallest possible number of tools is necessary and that the sheet material consumption is substantially reduced.

The same task is also the DE 103 34 483 A1 underlying, which proposes to clamp the output board edge in a bead element, said bead is slidably mounted in the forming tool.

Deviating from the proposed solution of DE 103 34 483 A1 a method according to the features of claim 1 is proposed. The dependent claims relate to preferred developments. Furthermore, a forming tool according to the independent claim is proposed. The solution of the problem also extends to a produced by the method and / or forming tool sheet metal part, which is primarily a body part and in particular is an outer skin part or structural part.

The method according to the invention serves to produce a complex sheet metal part which is essentially ready to be molded from the shape of a sheet material. "Substantially ready to install" means that the sheet metal part produced subsequently no significant, the molding characteristics changing forming operations are performed more.

• – Bereitstellen einer insbesondere ebenen, durch einen Außenrand in ihrer Form definierten Ausgangsplatine aus einem Blechmaterial, insbesondere aus einem Feinblechmaterial eines Stahl- oder Aluminiumwerkstoffs;
• – Einlegen dieser Ausgangsplatine in ein Umformwerkzeug und Schließen des Umformwerkzeugs, wobei ein Einspannen und insbesondere festes Einspannen bzw. Einklemmen der Ausgangsplatine zumindest in einem randnahen Abschnitt bzw. Flächenabschnitt erfolgt;
• – zumindest teilweises Abkanten wenigstens eines bezüglich des eingespannten randnahen Abschnitts außenliegenden Flanschabschnitts der Ausgangsplatine; und
• – Umformen wenigstens eines bezüglich des eingespannten randnahen Abschnitts innenliegenden Flächenabschnitts der Ausgangsplatine, insbesondere mittels wenigstens eines zum Umformwerkzeug gehörenden Formstempels, wobei ein Nachfließen des Blechmaterials aus dem eingespannten randnahen Abschnitt weitgehend bzw. im Wesentlichen unterbunden ist.

The method according to the invention comprises the following steps:

• - Providing a particular flat, defined by an outer edge in its shape output board of a sheet material, in particular of a sheet material of a steel or aluminum material;
• - Inserting this output board in a forming tool and closing the forming tool, wherein a clamping and in particular fixed clamping or pinching the output board takes place at least in a near-edge portion or surface portion;
• - At least partially folding at least one with respect to the clamped edge near portion outer flange portion of the output board; and
• - Forming at least one with respect to the clamped edge near portion inside surface portion of the output board, in particular by means of at least one belonging to the forming die, wherein a Nachfließen the sheet material from the clamped near-edge portion is substantially or substantially prevented.

A "folding" is understood to mean the stopping (or bending or also bending) of a surface section of the sheet metal material with respect to another surface section along a bending line or bending edge.

Individual steps of the procedure may overlap in time. In addition, the method may have in detail unspecified intermediate steps and / or sub-steps. When the shaping is completed, the forming tool is opened and the essentially ready-to-install or verbaufertige sheet metal part can be removed. Subsequently, no more cutting operations are provided (although this would be possible), which saves cutting tools compared to the current production methods and the sheet material consumption can be significantly reduced by up to 50%, which has a decisive positive influence on the manufacturing cost. Consequently, it is a waste-free design.

The forming of an inner surface portion in which z. B. a free-form surface is formed takes place in a stretch-drawing process, wherein a subsequent flow of the sheet material due to the clamping of the output board and the bending of the sheet material outside this clamping is effectively prevented. In the forming tool, therefore, no or only slight relative movements occur between the sheet metal material and the tool parts or their active surfaces involved in the shaping, so that also advantageous coated and in particular painted or laminated sheet materials can be formed.

The shaping steps of the method according to the invention are preferably carried out in only one forming tool. Ie. the sheet metal part is finished in a forming tool (Gesamtformstufe) with in particular a hub. Compared to today's manufacturing process thus forming tools can be saved. Because of the lower investment costs, the invention is particularly suitable for the application of small quantities. A forming tool which is suitable for carrying out the method according to the invention is the subject of the independent claim. Such a forming tool is usually installed in a forming press and comprises a plurality of tool parts which are axially movable relative to each other and separately from one another, as explained in more detail below in connection with the figures.

A clamped or clamped sections can be divided into several sections. According to a preferred embodiment, it is provided that the clamping of the output board in the forming tool takes place along a circumferential edge near section. The term "near the edge" refers to the outer edge of the output board. Preferably, between a clamped portion and the outer edge is still a abzukantender flange.

According to a preferred embodiment, it is provided that the width of the clamped edge near section is at least 5 mm, preferably at least 10 mm, particularly preferably at least 20 mm and in particular at least 40 mm. A preferred upper value is 200 mm in each case. This width is determined in a direction perpendicular to the outer edge of the output board.

According to a particularly preferred embodiment, it is provided that during clamping of the output board already has a defined shape, which later appears on the ready-to-install sheet metal part. For this purpose, provided for clamping or clamping tool parts or their active surfaces are to be designed accordingly. This makes it possible to form contour edges already at the beginning of the shaping, which are used for the mechanical reinforcement of the sheet metal part and / or as design elements (eg character lines), wherein their expression can be further increased in subsequent shaping steps. Such contour edges and / or design elements are usually introduced into the sheet material in a Nachformungsschritt in accordance with the current production methods.

According to a preferred embodiment, it is provided that the output board is folded circumferentially. For this, it may be necessary to provide cutouts in corner areas when cutting the output board. The folding preferably takes place directly adjacent to a clamped section along a defined bending line or bending edge. The bending line is preferably straight. However, the bending line may also have a curved course.

According to a preferred development, it is provided that the bending angle at the bending edge amounts to a maximum of 140 °, preferably a maximum of 120 °, particularly preferably a maximum of 100 ° and in particular about 90 °. The bending angle indicates the angle between the folded flange portion and the adjacent sheet metal plane. Different flange sections can be folded with different bending angles. A bending angle can also have a variable course.

The retention or retention of the sheet metal material can be adjusted primarily via the choice of the clamping force, the bending angle and / or the bending radius along the bending edge.

According to a preferred embodiment, it is provided that the sheet material is folded double when folding, whereby the retention can be strengthened. This will be explained in more detail below in connection with the figures.

According to a preferred embodiment, it is provided that at least one counter-shaped surface section is formed within at least one inner surface section and in particular already formed inner surface section in a counter-deformation. In this way, by means of the forming tool used for shaping also so-called. Gegenformelemente can form.

According to a preferred embodiment, it is provided that at the end of molding a compression molding takes place. Here, applying high forming forces between at least two active surfaces of the forming tool, a final calibration of the sheet metal part is carried out to dimensional accuracy.

According to a preferred embodiment, it is provided that in at least one surface section, the sheet material is provided with a structuring. The structuring can be patterned and z. B. during compression molding, as described above, are generated. Such structuring serves primarily to increase the mechanical stability of the sheet metal part. Such Structuring can also be created in a clamped near-edge section.

According to a preferred embodiment, it is provided that the blank of the output board deviates from a planar development of the sheet metal part. When determining the cut, the stretch-draw components must be taken into account. In particular, it is additionally provided that holes which are already in the exact position and / or recesses are introduced into the blank before forming, which ideally takes place during the blank production.

The invention will be explained in more detail by way of example with reference to the figures. Show it:

1 a produced by the novel process sheet metal part in a perspective view and its output board in a plan view;

2 in a sequence of an inventive shaping of the sheet metal part from the 1 in several schematic views;

3 in a detail drawing a double fold in a schematic view; and

4 a further produced by the novel process sheet metal part in a perspective view.

1a shows a prepared by the process according to the invention complex sheet metal part 20 which is formed of a sheet material. In the shown sheet metal part 20 is it z. B. to an outer skin part for a motor vehicle body. The sheet metal part 20 has circumferentially bent flange portions, of which in the illustration shown only the flange portions 21 and 22 are visible. The flange sections are along bending edges 23 to 26 with a bending angle of about 90 ° with respect to the adjacent metal sheets of the sheet metal part 20 angled. The bending edges 23 to 26 comprise a central inner surface section 27 , which can also be called a mid-range. This central interior surface section 27 is along a contour edge 29 to a circumferential near-edge section or area section 28 delimited, this directly to the bending edges 23 to 26 adjacent marginal section 28 is firmly clamped during shaping in the forming tool between at least two corresponding tool parts, as explained in more detail below. Furthermore, the sheet metal part 20 in the inner surface section 27 a counter-shaped surface section 30 on, where it is z. B. can act as a recessed grip.

1b shows the output board 10 , from which in the 1a shown sheet metal part 20 is produced by the method according to the invention. The output board 10 is cut in a preceding cutting process from a metal sheet or a Blechcoil. In general, the shape of the output board corresponds 10 not an exact handling of the sheet metal part 20 in the plane. The output board 10 has an outer edge 11 on, with this outer edge 11 after shaping also forms the outer edge of the sheet metal part. The bending lines 23 to 26 along which the flange sections are bent, as well as the contour edges formed during the molding 29 and the counter-shaped surface portion 30 are shown by dashed lines. In the corner areas between the flange sections free cuts 12 provided, as an example between the flange sections 21 and 22 specified.

The following is based on the 2 the production of the sheet metal part 20 in a sequence starting from the provided output board 10 explained. The shaping takes place in a forming tool which is a tool upper part 110 and a tool base 120 is incorporated and in a multi-acting forming press (not shown) is installed, which provides the forming force required for the shaping. Preferably, the complete shaping takes place during a press stroke.

After the exact insertion of the output board 10 into the opened forming tool 100 becomes the forming tool 100 by axial relative movement of the upper tool 110 to lower tool part 120 closed, taking first the output board 10 in the circumferential near-edge section 28 (see. 1 ) firmly between an upper clamping frame 111 and a lower clamping frame 121 is clamped, as in 2a shown. The flange sections of the output board 10 stand outwards over the clamping frames 111 and 121 as shown on the right side with the reference numeral 22 specified. Closing the forming tool 100 and clamping the output board 10 can also be decoupled from each other. The clamping or the clamping of the near-edge section 28 the output board 10 ideally remains throughout the shaping. With 131 is a positioning element for exact insertion of the output board 10 designated.

When clamping the output board 10 between the clamping frames 111 and 121 already takes place a first shaping, in which the contour edges 29 (see. 1 ) are formed or at least partially formed, including the clamping frame 111 and 121 are formed with corresponding active surfaces. As in 2a shown by way of example, the clamping of the output board takes place 10 on same level, but this does not necessarily have to be the case.

In a subsequent step, the over the clamping frame 111 and 112 outwardly projecting flange portions by means of an upper tool 110 belonging Abkantrahmens 112 bent downward, for example, so that these flange sections a Abkantwinkel of about 90 ° to the sheet plane of the clamped output board 10 taking. This is in 2 B shown. (Depending on the tool design, it is also possible to edge the outwardly protruding flange sections in different directions.)

In a subsequent step is now with respect to the clamped near-edge section 28 internal center area of the output board 10 , the inner surface section 27 forms, by means of one to the lower tool 120 belonging form stamp 124 reshaped, as in 2c shown. Depending on the desired geometry of the sheet metal part 20 The die can also in the upper tool 110 be arranged. The reshaping of the inner surface portion, wherein this surface portion substantially the contour of the punch working surface of the forming punch 124 takes place, carried out in a ironing process in which a subsequent flow of the sheet material from the surrounding, near-edge section 28 is prevented, which by clamping between the clamping frame 111 and 121 and achieved by the folding of the flange sections. Also the Abkantrahmen 112 ideally retains its position during reshaping of the inner surface portion. When reshaping the inner surface section, the expression of the contour edges also becomes the same 29 strengthened.

An essential idea of the invention is to be seen in the fact that the retention or retention of the sheet material during shaping takes place within the sheet metal part geometry (sometimes the retention takes place in flange sections located outside with respect to the sheet metal part geometry), thereby saving sheet material, but also the overall smaller and can be sized more easily. The latter makes it possible for several forming tools according to the invention to be installed in a press if necessary. Any removal of the retaining elements (clamping frame) in the sheet metal material can be used for the targeted introduction of contour edges and / or design elements, as explained above.

In a subsequent step, the formation of the counter-shaped area section now takes place 30 (see. 1 ) by means of an upper tool 110 belonging Gegenstempel 114 , as in 2d shown. This can then be followed by compression molding, the two punches 114 and 124 be pressed against each other with great force.

The forming tool 100 is now by axially moving away the upper part of the tool 110 relative to the lower tool part 120 (or vice versa) opened and the finished sheet metal part 20 can be removed. The folded flange sections may, for. B. for installation of the sheet metal part 20 be used.

A forming tool 100 , which is suitable for carrying out the method according to the invention and in particular its shaping steps, can be realized with different tool designs depending on the requirements. The concrete design of such a forming tool is within the skill of the art.

3 shows in a detailed view by way of example a preferred double fold of the flange portion 22 , Here, the outer portion of the flange portion 22 by means of a bottom tool belonging to the lower Abkantrahmens 212 bent in a reverse direction. As a result, a stronger retention of the sheet material can be realized. The selected bending angles and / or radii depend on the desired retention and / or on the structurally predetermined sheet metal part geometry. In 3 is also the possible formation of a contour edge 29 by means of the clamping frame 111 and 121 clearly illustrated.

4 shows another produced by the novel process sheet metal part 20a , Notwithstanding the in 1a shown sheet metal part 20 was the output board during molding only in the two near-edge sections or surface sections 281a and 282a , and thus not encircling, clamped, whereupon the respective outer flange portions were bent, as shown on the front flange portion 21a shown. This was followed by the transformation of the surface section 27 (which in this case is only a partial stretch-forming). For example. can be a large-sized sheet metal component of several sheet metal parts 20a be composed, which at the open, ie not folded outer edges, in particular overlapping, are joined together.

LIST OF REFERENCE NUMBERS

10

output board

11

outer edge

12

Clear cut

20

complex sheet metal part

21

flange

22

flange

23-26

Bending edge (s)

27

internal surface section

28

near-edge section

281, 282

marginal sections

29

contour edge

30

counter-shaped area section

100

forming tool

110

upper tool

111

upper clamping frame

112

Upper bending frame

114

Against forming die

120

lower tool

121

lower clamping frame

122

lower frame

124

Shaping stamp, drawing punch

131

Positioning (e)

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10334483 A1 [0004, 0005]

Claims (14)

Process for producing a complex sheet-metal molded part which is essentially ready for molding ( 20 ), comprising the following steps: - providing an output board ( 10 ) of a sheet material; - insert the output board into a forming tool ( 100 ) and closing this forming tool, wherein a clamping of the output board ( 10 ) at least in a section close to the edge ( 28 ) he follows; - Bending at least one with respect to the clamped edge near section ( 28 ) outer flange portion ( 21 . 22 ) of the output board ( 10 ); and - forming at least one with respect to the clamped near-edge portion ( 28 ) inner surface section ( 27 ) of the output board ( 10 ), wherein a subsequent flow of the sheet material from the clamped near-edge portion ( 28 ) is substantially prevented. A method according to claim 1, characterized in that the clamping of the output board ( 10 ) along a circumferential edge near section ( 28 ) he follows. A method according to claim 1 or 2, characterized in that the width of the clamped edge near section ( 28 ) is at least 5 mm, preferably at least 10 mm, particularly preferably at least 20 mm and in particular at least 40 mm. Method according to one of the preceding claims, characterized in that during clamping of the output board ( 10 ) already has a defined shaping, which is located on the ready-to-install sheet metal part ( 20 ). Method according to one of the preceding claims, characterized in that the output board ( 10 ) is folded circumferentially. Method according to one of the preceding claims, characterized in that the bending angle is at least 140 °, preferably at least 120 ° and in particular 90 °. Method according to one of the preceding claims, characterized in that the sheet metal material is folded double during bending. Method according to one of the preceding claims, characterized in that within at least one reshaped surface section ( 27 ) in a counter-forming at least one counter-shaped surface portion ( 30 ) is formed. Method according to one of the preceding claims, characterized in that at the end of molding a compression molding takes place. Method according to one of the preceding claims and in particular according to claim 8, characterized in that in at least one surface section ( 27 ) the sheet material is provided with a structuring. Method according to one of the preceding claims, characterized in that a blank of the output board ( 10 ) of the flat development of the sheet metal part ( 20 ) deviates. A method according to claim 11, characterized in that prior to forming already positionally accurate perforations and / or recesses are introduced into the blank. Forming tool ( 100 ) which is suitable for carrying out a method and in particular the shaping steps according to one of the preceding claims. Sheet metal part produced by a method and / or with a forming tool ( 100 ) according to any one of the preceding claims.

Images