Molding Tool for Producing Hot-Formed Components

Abstract

A molding tool is provided for producing hot-formed components, in particular formed sheet metal parts. The molding tool includes a tool lower part and a tool upper part which are movable in relation to each other, and which include corresponding operative faces for shaping a hot-formed component. The operative face of at least one of the tool parts is configured so as to be coolable and that tool part includes cooling lines therein. At least one of the tool parts includes a clearance which in a closed state of the molding tool, conjointly with the hot-formed component, forms an air chamber. The air chamber functions as a thermal insulator between the hot-formed component and the tool part.

Claims

1. A molding tool for producing a hot-formed component such as a formed sheet metal part, comprising: a tool lower part and a tool upper part which are movable in relation to each other, and which include corresponding operative faces for shaping the component, where the operative face of at least one of the tool lower and upper parts is at least in part configured so as to be coolable and the at least one of the tool lower and upper parts includes cooling lines therein, wherein at least one of the tool lower and upper parts includes at least one clearance which in a closed state of the molding tool, conjointly with the component, forms an air chamber which functions as a thermal insulator between the component and the at least one of the tool lower and upper parts which includes the at least one clearance.

2. The molding tool according to claim 1, wherein the at least one clearance is configured so as to be variable in volume.

3. The molding tool according to claim 1, wherein the at least one of the tool lower and upper parts which includes the at least one clearance has an insert therein that forms a tool-side rear wall of the air chamber.

4. The molding tool according to claim 2, wherein the at least one of the tool lower and upper parts which includes the at least one clearance has an insert therein that forms a tool-side rear wall of the air chamber.

5. The molding tool according to claim 3, wherein the insert is movably disposed in the at least one of the tool lower and upper parts which includes the at least one clearance.

6. The molding tool according to claim 5, wherein the insert is displaceable in a linear manner.

7. The molding tool according to claim 5, wherein the insert in a closed state of the molding tool is in a retracted position in order for the at least one clearance to be generated.

8. The molding tool according to claim 6, wherein the insert in a closed state of the molding tool is in a retracted position in order for the at least one clearance to be generated.

9. The molding tool according to claim 5, wherein the insert in an opened state of the molding tool is in an advanced position in which a volume of the at least one clearance is reduced in relation to a volume of the at least one clearance in a retracted position of the insert.

10. The molding tool according to claim 8, wherein the insert in an opened state of the molding tool is in an advanced position in which a volume of the at least one clearance is reduced in relation to a volume of the at least one clearance in a retracted position of the insert.

11. The molding tool according to claim 3, wherein the insert includes ducts therein.

12. The molding tool according to claim 10, wherein the insert includes ducts therein.

13. The molding tool according to claim 1, wherein the hot-formed component is a formed sheet metal part configured from either a ferrous metal or a non-ferrous metal.

14. The molding tool according to claim 13, wherein the formed sheet metal part is configured at least in part from one of steel, aluminum and magnesium.

15. The molding tool according to claim 3, wherein the insert is configured from metal, non-metal, or a combination thereof.

16. The molding tool according to claim 15, wherein the non-metal includes concrete and wood.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0021] FIG. 1 is a sectional view through a molding tool.

DETAILED DESCRIPTION OF THE DRAWING

[0022] FIG. 1 shows a molding tool 10 that is employable in presses for hot-forming tools, in particular sheet metal blanks, to form sheet metal components 17. The molding tool 10 has a lower tool half 12u which bears on a base plate 11. The lower tool half 12u interacts with an upper tool half 12o. The mutually facing operative faces of the upper tool half 12o and the lower tool half 12u are configured so as to be mutually corresponding such that they act like a die and a punch of a press tool. In the example illustrated in FIG. 1, the upper tool half 12o is configured as the punch, and the lower tool half 12u is configured as the die. Without departing from the scope of the invention, in alternative embodiments (not shown), the upper and the lower molding-tool halves may be reversed in terms of their arrangement, such that the upper tool functions as a die, and the lower tool functions as a punch. The upper tool half 12o and the lower tool half 12u are movable in relation to one another. The molding-tool halves 12o, 12u, as illustrated in FIG. 1, can be moved apart and moved back together. During moving together of the molding-tool halves, a sheet metal piece or a sheet metal blank is caught between the molding-tool halves, and is encompassed and formed by the operative faces of the molding-tool halves 12o, 12u. The state illustrated in FIG. 1 corresponds to a terminal position of the tool halves 12u, 12o in the case of a forming procedure in which the sheet metal component 17 is fully formed.

[0023] An insert 16 which is movable along the double arrow B in relation to the upper tool half 12o is shown in the upper tool half 12o. The insert 16 is thus displaceable in a linear manner in the direction toward the component 17, and away from the component 17. The insert 16 in FIG. 1 carries out a linear movement that is substantially perpendicular to the component surface. Alternatively thereto, a movement that is oblique to the component surface may also be carried out, however. In the closed state of the tool 10, as illustrated in FIG. 1, the insert 16 forms a clearance 15. The clearance 15 functions as a chamber which is filled with air. This chamber 15 is encompassed by a surface of the insert 16 that faces the component 17, by an internal surface of the breakout through the upper tool half 12o, the insert 16 being incorporated therein, and by a portion of the surface of the component 17. The air in this chamber 15 insulates the warm sheet metal part 17 emerging from the furnace in relation to the upper tool half 12o and the insert 16 that is located in the latter. Thus, the heat transfer from the component 17 to the molding tool 10 at this location is slower than in the remaining component regions in which the component 17 is in direct physical contact with the tool 10. The component 17 in the region of the air chamber 15 cools more slowly, such that a microstructure having low mechanical characteristics, in particular having low strength values, is established in this region. The air gap 15 thus covers exactly that region that in the later component, or vehicle, respectively, is characterized by low strength and thus high ductility. The properties of the component may thus be set such that targeted deformation of the ductile region results in the case of a vehicle crash.

[0024] The size of the air chamber 15 may be varied by displacing the insert 16. Depending on the chosen position of the insert 16, that is to say depending on the size of the air chamber 15, correspondingly different desired strength values may be set in the region of the component. The air chamber 15 herein, having in particular a small volume, may also be configured as a gap.

[0025] As an alternative to the medium of air, other gases may also be used for filling the chamber 15.

[0026] According to one embodiment of the invention, ducts 18 which serve for controlling the temperature of the insert may optionally be disposed in the insert 16.

[0027] To this end, the insert 16 is purged with a temperature-controlled medium, and is set to a predetermined temperature. The medium herein is pre-temperature-controlled in a heating and/or cooling installation, and is directed through the ducts 16 of the insert 18. The temperature of the insert 16 and thus of the air in the chamber 15 may thus be controlled or regulated by way of the temperature of the medium. Gases, for example inert gases, or liquids, for example oil or water, are particularly suitable as media. However, the provision of ducts 18 is only optional. In other embodiments of the invention, the insert 16 may also be configured without the medium-carrying ducts 18.

[0028] A mold insert 13 in which a cooling system that has a plurality of cooling lines 14 is integrated is provided in the lower molding-tool half 12u. On the one hand, the use of molding insert 13 of this type offers the advantage that dissimilar component contours may be embossed using one lower molding tool 12u, in that the mold insert 13 may be replaced so as to correspond to the desired component shape. The cooling lines 14 are in fluidic communication with a distributor or connector system. The coolant is thus introduced by way of the connector system and distributed to the cooling lines 14.

[0029] The cooling lines 14 illustrated in FIG. 1 run in a manner substantially parallel with the surface of the component 17, and thus also substantially parallel with the operative face of the molding-tool halves 12u, 12o. The cooling lines 14 thus follow the component contour at a specific spacing therefrom into the mold insert 13 of the lower molding-tool half 12u.

[0030] Gaseous cooling media, liquid cooling media, or a combination thereof are suitable as coolants for the cooling lines 14.

[0031] Only a single insert 16 which is disposed in the upper tool part 12o is depicted in FIG. 1. In the case of a further embodiment of the invention (not illustrated), the insert may be disposed in the lower tool part 12u. Alternatively, one or a plurality of inserts 16 may be positioned both in the upper as well as in the lower tool half 12o, 12u. Moreover, only the lower tool half 12u is provided with cooling lines 14 in the exemplary embodiment shown in FIG. 1. Alternatively thereto, the arrangement of the cooling system, that is to say the connector system and the cooling lines 14, in further embodiments of the invention, may also be disposed in the upper tool half 12o. In one further alternative embodiment, cooling lines 14 may be provided both in the upper tool half 12o as well as in the lower tool half 12u. Moreover, a mold insert 13 may alternatively be disposed in the upper tool half 12o, or in both tool halves.

LIST OF REFERENCE SIGNS

[0032] 10 Molding tool [0033] 11 Tool base plate [0034] 12u Tool lower part [0035] 12o Tool upper part [0036] 13 Tool insert [0037] 14 Cooling lines [0038] 15 Clearance [0039] 16 Insert [0040] 17 Component [0041] 18 Ducts

[0042] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.