METHOD FOR FORMING A SHEET BLANK AS A WORKPIECE IN A FORMING TOOL

Abstract

A method is provided for forming a flat metal blank as a workpiece in a forming die.

Claims

1. A method of forming a flat metal blank as a workpiece in a forming die, comprising the steps of: providing a forming die with at least one cavity; providing at least one blankholder for fixing a workpiece to the at least one cavity during the forming; heating the workpiece to a solution heat treatment temperature; and forming the material of the workpiece to be formed by selecting a pressure of the at least one blankholder or of a marginal region of the at least one cavity onto the workpiece to enable the material of the workpiece to flow from a region of the at least one blankholder or of the marginal region of the at least one cavity into the cavity; and/or actively pushing the material of the workpiece into the at least one cavity, or forming entirely without any additional workpiece material in the at least one cavity.

2. A method of forming a hollow body blank as a working piece in a forming die, comprising the steps of: providing at least one locking apparatus for a hollow body blank; providing a forming die with at least one cavity for receiving the hollow body blank during the forming; heating the hollow body blank to a solution heat treatment temperature; and forming the hollow body blank by holding the hollow body blank by the at least one locking apparatus to enable the material of the hollow body blank to flow into the cavity; and/or actively pushing the material of the hollow body blank into the at least one cavity, or forming on the basis of the material of the hollow body blank that is located within the cavity.

3. A method in accordance with claim 1, wherein the process of heating the flat metal blank to the solution heat treatment temperature is concluded before the start of the forming.

4. A method in accordance with claim 1, wherein the forming of the flat metal blank begins during the process of heating the flat metal blank to the solution heat treatment temperature.

5. A method in accordance with claim 4, wherein process of heating the flat metal blank to the solution heat treatment temperature is concluded during the forming of the flat metal blank.

6. A method in accordance with claim 1, wherein the flat metal blank is heated to the solution heat treatment temperature before the introduction into the forming die.

7. A method in accordance with claim 1, wherein the flat metal blank is removed from the forming die and is supplied to a hardening process after conclusion of the forming process and/or after conclusion of the heating process.

8. A method in accordance with claim 7, wherein the hardening process comprises a cooling process and/or a forming process in a further forming die.

9. A method in accordance with claim 1, further comprising a step of setting a temperature profile in the at least one cavity by a temperature control device in dependence on the formation of a material reserve at the flat metal blank desired at a predefined location in the at least one cavity.

10. A method in accordance with claim 1, further comprising a step of applying a roughness profile to the at least one cavity in dependence on the formation of a material reserve at the flat metal blank desired at a predefined location in the at least one cavity.

11. A method in accordance with claim 9, further comprising: a step of applying a roughness profile to the at least one cavity in dependence on the formation of a material reserve at the flat metal blank desired at a predefined location in the at least one cavity; and applying the temperature profile in the region of the arrangement of the roughness profile in the at least one cavity.

12. A method in accordance with claim 1, wherein the forming takes place under gas pressure and/or mechanically.

13. A method in accordance with claim 1, further comprising a step of providing a sealing element for gas forming to minimize the outlet of gas between the flat metal blank and the at least one cavity, or the flat metal blank and the at least one blankholder, or between the at least one blankholder and the flat metal blank.

14. A method in accordance with claim 1, wherein subsequent to the forming process, the flat metal blank is captured by the at least one blankholder, or by the at least one cavity to prevent the flow of the flat metal blank material into the at least one cavity for a calibration of the flat metal blank in the at least one cavity, the calibration being provided by a high gas pressure up to 1000 bar.

15. A method in accordance with claim 1, wherein the cycle time between the charging of the forming die with the flat metal blank to be formed and the removal of the formed flat metal blank from the forming die amounts to a minute; on forming under gas pressure 20 seconds; and on a mechanical forming 10 seconds.

16. A method in accordance with claim 1, wherein the forming die and/or the flat metal blank is/are set to the solution heat treatment temperature specific to the flat metal blank.

17. A method in accordance with claim 1, wherein the heat treatment temperature follows a heat treatment temperature profile.

18. A method of forming a flat metal blank or a hollow body blank having at least one aperture in one or more forming dies arranged behind one another in a forming press line, comprising the step of forming that takes place in the solution heat treatment temperature range or in the austenitization temperature range of the material of the flat metal blank or hollow body blank to be formed with cycle times for a hollow body blank of less than 40 seconds or less than 20 seconds, and for a flat metal blank less than 30 seconds, or between 4 and 10 seconds.

19. A method in accordance with claim 18, wherein the heat treatment temperature follows a heat treatment temperature profile.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The invention will be described in more detail below by way of example with reference to the drawings. There are thus shown

[0022] FIG. 1a and FIG. 1b show a forming press for forming a metallic flat blank using mechanical forming and additionally with gas pressure forming;

[0023] FIG. 1c to FIG. 1e show a forming process of a flat metal blank in three steps in different tools; and

[0024] FIG. 2 shows a forming press for the forming of a hollow body blank.

DETAILED DESCRIPTION OF THE INVENTION

[0025] In detail, the cavity or die is shown by 2 and the punch by 3 in the forming press 1 of FIGS. 1a-1e. A gas supply is schematically indicated by 4. The flat metal blank has the reference numeral 10.

[0026] In this connection, a cavity or die and a punch for a purely mechanical forming of the flat metal blank 10 results from FIG. 1a. A blankholder for the flat metal blank has the reference numeral 6.

[0027] FIG. 1b shows a mechanical forming in combination with a gas pressure calibration, with here a gas supply 4 being provided in the region above the flat metal blank, that is in the region of the punch 3. A blankholder 6 is also provided here. The blankholder applies a pressing force onto the flat metal blank in conjunction with the cavity or die 2.

[0028] FIG. 1c shows a forming press in which the forming takes place by internal gas pressure in a first forming step. An internal pressure of, for example, 20 bar can be provided here, and indeed in dependence on the wall thickness and on the material, with material being able to be pushed into the cavity actively above the lower tool frame 5 in order to have sufficient material available, for example in a subsequent cold forming.

[0029] FIG. 1d shows a purely mechanical forming as a second forming step using a punch 3 and a cavity or die 2, with the material of the workpiece being able to be freely tracked. A free material feed is also spoken of here.

[0030] In FIG. 1e, a gas feed 4 into the space above the punch 3 is in turn provided for calibration in the third forming step, with the surface of the formed component being smoothed with a closed die at a high pressure of up to approximately 1000 bar, advantageously up to 200 bar, with sealed marginal regions. No material advance into the cavity takes place here.

[0031] FIG. 2 shows a forming press 1 having two die halves 2 for forming a hollow body blank 11. The hollow body blank is supported in the region between the die halves, with the cavities forming the negative mold for the final form formed from the hollow body blank. The blank sealing and blank feeding or locking apparatus 12 engages laterally at the hollow body blank. The locking apparatus 12 comprises a sealing cylinder 13 at each of the two sides of the hollow body blank that is also able push material of the hollow body blank into the space between the two cavities. At least one of the cylinders 13 can have an opening 4 for supplying a gas for forming the hollow body blank.

REFERENCE NUMERAL LIST

[0032] 1 forming press [0033] 2 cavity or die [0034] 3 punch [0035] 4 gas supply [0036] 5 lower tool frame [0037] 6 blankholder [0038] 10 flat metal blank [0039] 11 hollow body blank [0040] 12 locking apparatus [0041] 13 cylinder of the locking apparatus