DE102009037362A1 - Method and device for post-forming sheet metal - Google Patents

Abstract

The invention relates to a method for the post-forming of sheet metal (1), in particular magnesium and / or aluminum-containing light metal sheet for motor vehicles in the area of their edges. According to the invention, a) a preformed sheet (1) is positioned on a storage surface (2), b) a hold-down device is lowered onto the sheet (1), c) after the sheet (1) has been heated to the forming temperature, by lowering the sheet ( 1) brought into contact with the support surface (2) and the hold-down device (3) and / or by lifting a folding punch (4, 5) with the surface of the folding punch (2), d) a folding slide (6) on the for reshaping Areas to be formed (9a) and the edge (10) of the sheet (1) are moved and e) after releasing the hold-down device (3), the folding ram (4, 5) and the folding slide (6), the post-formed sheet (1) from the storage surface is removed.

Description

The The invention relates to a method for post-forming sheet metal, in particular magnesium and / or aluminum-containing lightweight sheets for motor vehicles in the area of their edges and a device for carrying out the method.

magnesium is an extremely lightweight material that has been mainly because of its relatively low elongation at break in the automotive industry rather rarely used. By heating the board or However, the forming properties, the forming properties can significantly be improved.

From the DE 101 28 199 A1 For this purpose, a device for forming metal sheets, in particular magnesium sheets is known, wherein the metal sheet in the forming space between the upper and lower tool should be at least partially heated. For this purpose, hot air is passed through provided in the upper tool and / or lower tool flow channels in the forming space. Proposed is also an indirect heating, wherein the heat transfer via the press tool, ie upper tool and / or lower tool, which in turn are heated, takes place. The hot forming should be carried out at temperatures between 90 ° and 350 ° C, preferably at a temperature of about 280 ° C.

at the manufacture of larger vehicle components, z. B. in the production of a roof skin made of magnesium It is often necessary after a first forming process to further reshape the edge areas of the sheets by post-forming. Here, above all, the relatively high thermal expansion coefficient applies to be considered by magnesium. The dimensions of the reshaped Components can vary depending on the size of the component Change significantly when heating up to the required forming temperature. There are special features for the tool function, in the design of a post-mold resource for Magnesium sheets must be considered. Since the nachzuformende component in the cold state not yet on the larger, considering the thermal expansion Nachformstempel fits and is not sufficiently formable, must this special measures are taken.

Of the The invention is therefore based on the object, a method and a Apparatus for reshaping sheets, in particular magnesium and / or To propose aluminum-containing lightweight sheets, in which the mentioned problems do not occur.

• a) ein vorgeformtes Blech auf einer Ablagefläche positioniert,
• b) ein Niederhalter auf das Blech abgesenkt,
• c) nach Aufheizen des Bleches auf Umformtemperatur dieses durch Absenken des Bleches gemeinsam mit der Auflagefläche und dem Niederhalter und/oder durch Anheben eines Abkantstempels mit der Oberfläche des Abkantstempels in Berührung gebracht,
• d) zur Nachumformung ein Abkantschieber auf die umzuformenden Bereiche und den Rand des Bleches zubewegt und
• e) nach Lösen des Niederhalters, des Abkantstempels und des Abkantschiebers das nachumgeformte Blech von der Ablagefläche entnommen wird.

To solve this problem, a method is proposed, wherein

• a) positioned a preformed sheet on a shelf,
• b) lowered a hold-down on the sheet,
• c) after heating the sheet to forming temperature of this brought by lowering the sheet together with the support surface and the blank holder and / or by raising a Abkantstempels with the surface of the Abkantstempels,
• d) for Nachumformung a Abkantschieber moved to the reshaped areas and the edge of the sheet and
• e) after loosening the hold-down, the press brake and the press brake, the reshaped sheet is removed from the shelf.

According to the invention So the sheet before post-forming, ideally heated in the tool, wherein preferably at least one of the tools, ie the storage surface, the hold-down and the punch stamp directly and / or indirectly heated and only after reaching the required forming temperature the Abkantstempel with the edge of the sheet to be formed associated, then the actual Bend gate the edge area around the existing on the punch punch outer Contour can shape around.

The invention will be apparent from the attached 1 - 6 for example, explained in more detail. Show it

1 in plan view and schematically, apart from the hold-down 3 the forming tools, punch marks 4 and 5 and folding gate 6 .

2 a cut to the line AA too 1 .

3 a section along the line BB of 1 in the heating phase,

4 a section along the line BB of 1 in the phase of lowering and closing the tools,

5 a section along the line BB of 1 in the phase of reshaping and

6 a section along the line BB of 1 in the phase of removal of the reshaped component.

In the figures, the structure of a resource for reshaping an edge flange with undercut for a metal sheet 1 made of magnesium. The equipment has a be heatable, designed as a controllable lifting element storage space 2 for the sheet metal 1 , wherein the nachzuformende sheet 1 in an ascending position over as large a storage area as possible 2 is brought to the appropriate forming temperature. Since the temperature application is best carried out from both sides and in the clamped state, as a counter bearing is also a heatable, preferably full-surface resting hold-down 3 intended. After the heating phase, the sheet is 1 on the, after the thermal expansion suitable, preferably also heated Abkantstempel 4 . 5 freely stored. In 2 this is a rigid punch stamp 4 while in the 3 - 6 a horizontally adjustable (see double arrow P4) movable Abkantstempel 5 , which is also referred to as a filling slide, is shown. These also heated filling slide are used in particular for forming undercuts, which are formed by the present at the upper left end of the filling slide projection. After positioning the press brake 4 or 5 takes place with closed downholder 3 the actual Nachformvorgang by moving the Abkantschiebers 6 in the direction of the double arrow P3. For removing the finished sheet 1 become the folding gate valves 6 moved back to their original position and the shelf space 2 in the direction of the double arrow P1 are moved upward, wherein also the spring-loaded hold-down 3 against the spring 8th in the direction of the double arrow P2 is moved upward and at the end so far away that the sheet can be removed (see. 6 ). The shelf 2 is using the spring 7 or a similar device controlled in the direction of the double arrow P1 moves.

In the 2 and 3 is additionally in dashed line the position of the reshaped area 9b of the sheet 1 shown if this is not heated. By heating the sheet 1 The area to be reshaped takes the position when hot 9a one, so the punch marks 4 and 5 can then be brought exactly in the forming position. In the 2 - 6 is also the outer edge of the sheet 1 With 10 designated while not on the support surface 2 resting part of the sheet 1 the outer area 11 forms.

The particular of the proposal according to the invention is that only after heating of the sheet 1 on forming temperature and thus only after reaching the final extent of the rigid Abkantstempel 4 or the formed as a filling slide Abkantstempel 5 is brought into the exact position.

LIST OF REFERENCE NUMBERS

1

sheet

2

shelf for 1 (controlled, heated lift)

3

Stripper plate (sprung and heated)

4

Abkantstempel (rigid, heated)

5

Abkantstempel (Filling slide, heated)

6

folding slide

7

feather

8th

feather

9a

re-shaping Range of 3 (heated up)

9b

re-shaping Range of 3 (cold)

9c

re-shaping Range of 3 (after reshaping)

10

edge Of 3

11

outer Range of 3 (not on 2)

P1

double arrow (Direction of movement of 2)

P2

double arrow (Direction of movement of 3)

P3

double arrow (Direction of movement of 6)

P4

double arrow (Direction of movement of 5)

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10128199 A1 [0003]

Claims (8)

Method for post-forming sheet metal ( 1 ), in particular magnesium and / or aluminum-containing lightweight sheets for motor vehicles in the region of their edges, wherein a) a preformed sheet metal ( 1 ) on a shelf ( 2 ), b) a hold-down device ( 3 ) on the sheet ( 1 ), c) after heating the sheet ( 1 ) to forming temperature this by lowering the sheet ( 1 ) together with the bearing surface ( 2 ) and the hold-down ( 3 ) and / or by raising a Abkantstempels ( 4 . 5 ) with the surface of the Abkantstempels ( 4 . 5 d) for reshaping a Abkantschieber ( 6 ) on the areas to be reshaped ( 9a ) and the edge ( 10 ) of the sheet ( 1 ) and e) after releasing the hold-down ( 3 ), the Abkantstempels ( 4 . 5 ) and the Abkantschiebers ( 6 ) the reshaped sheet ( 1 ) from the shelf ( 2 ) is taken. A method according to claim 1, characterized in that for heating the sheet ( 1 ) on forming temperature one or more of the forming tools shelf ( 2 ), Stripper plate ( 3 ), Punch marks ( 4 . 5 ) are heated directly or indirectly. Method according to claim 1 or 2, characterized in that the sheet ( 1 ) already heated on the shelf ( 2 ) is launched. Device for post-forming sheet metal ( 1 ), in particular magnesium and / or aluminum-containing lightweight sheets for motor vehicles in the region of their edges for carrying out the method according to the preceding claims with a bearing surface ( 2 ) for the sheets ( 1 ), a hold-down ( 3 ), Punch marks ( 4 . 5 ) and a Abkantschieber ( 6 ) for reshaping the sheet ( 1 ) in the edge region, characterized in that at least one of the tools storage surface ( 2 ), Stripper plate ( 3 ) and punch marks ( 4 . 5 ) are directly and / or indirectly heated. Apparatus according to claim 4, characterized in that the storage surface ( 2 ) is designed as a controlled lift. Device according to claim 4 or 5, characterized in that the hold-down device ( 3 ) is sprung trained. Apparatus according to claim 4, characterized in that the Abkantstempel ( 4 . 5 ) is vertically and / or horizontally movable. Apparatus according to claim 4, characterized in that the Abkantschieber ( 6 ) from the outside against the areas to be reshaped ( 9a . 10 ) of the sheet ( 1 ) is movable.

Images