Method and tool for calibration of a hollow profile component produced by extrusion for automobile manufacturing

Abstract

A method for the calibration or end sizing of a hollow profile component produced by extrusion for automobile manufacturing. The hollow profile component is inserted into the cavity of an opened press tool and closing the press tool. Expandable mandrels are introduced into the open profile ends of the hollow profile component. The hollow profile component is calibrated or end-sized by applying force simultaneously on the outside and on the inside. The expandable mandrels are retracted, opening of the press tool, and removing of the hollow profile component.

Claims

1. A method for the calibration or end sizing of a hollow profile component produced by extrusion for automobile manufacturing, comprising the steps: inserting the hollow profile component into a bottom tool part of an opened press tool and closing the press tool by lowering a top tool part of the press tool; introducing expandable mandrels into the open profile ends of the hollow profile component; calibrating or end sizing of the hollow profile component by use of a press ram traversing a height direction of the hollow profile component to simultaneously apply force to both the top tool part and the expandable mandrels, such that the hollow profile component is plastically deformed as a result of: exertion of an external force upon the hollow profile component by the top tool part and the bottom tool part; and expansion of the expandable mandrels transversely to a longitudinal direction of the hollow profile component in response to the force applied by the press ram, the expansion exerting an internal force upon the hollow profile component, and retracting the expandable mandrels, opening the press tool by raising the top tool part, and removing the hollow profile component.

2. The method as claimed in claim 1, wherein the expandable mandrels each comprise at least two mandrel jaws, a first wedge, and a second wedge, wherein the at least two mandrel jaws are forced apart via the first wedge, which is configured to move axially with respect to the hollow profile component being calibrated or end sized, wherein the first wedge is actuated by the second wedge, which acts upon a sloped surface of the first wedge, and wherein the second wedge is coupled to and acted upon by the press ram either directly or via the top tool part.

3. The method as claimed in claim 1, wherein only the end regions of the hollow profile component are calibrated or end sized.

4. The method as claimed in claim 3, wherein during the calibration, functional geometries are also formed in the hollow profile component.

5. The method as claimed in claim 1, wherein during the calibration, the cross section of the hollow profile component is scaled with a scaling factor of <1.

6. A press tool for the calibration or end sizing of an extruded hollow profile component for automobile manufacture, comprising: a bottom tool part and a top tool part, which are configured to move relatively to each other and which have a cavity for taking up the hollow profile component; two expandable mandrels, which are configured to be introduced into open profile ends of the hollow profile component taken up in the cavity; and a press ram, which is configured to traverse a height direction of the hollow profile component and which acts upon both the top tool part and the two expandable mandrels, simultaneously distributing force to both the top tool part and the two expandable mandrels, wherein the top tool part and the bottom tool part are further configured to exert an external force upon the hollow profile component in response to force applied by the press ram, and wherein the two expandable mandrels are further configured to expand transversely to a longitudinal direction of the hollow profile component in response to force applied by the press ram, thereby exerting an internal force upon the hollow profile component.

7. The press tool as claimed in claim 6, wherein the expandable mandrels each comprise a first wedge and at least two jaws, and wherein the at least two jaws are configured to be forced apart from one another by pushing the first wedge between the at least two jaws.

8. The press tool as claimed in claim 7, wherein the expandable mandrels each further comprise a second wedge, which acts upon a sloped surface of the first wedge to push the first wedge between the at least two jaws, wherein the second wedges are each coupled to and acted upon by the press ram either directly or via the top tool part.

9. The press tool as claimed in claim 6, wherein the bottom tool part is designed as a die and the top tool part as a punch.

10. A method for producing a hollow profile component for automobile manufacturing, comprising the steps: creating a hollow profile by extrusion; creating the hollow profile component by separating a piece from the hollow profile; and calibrating or end sizing the hollow profile component using the method according to claim 1.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) The invention shall now be explained more closely with reference to the drawing. The features shown in the figures of the drawing and/or explained below may be general features of the invention and enhance the invention accordingly, even independently from defined feature combinations.

(2) FIG. 1 shows a hollow profile component in a perspective view.

(3) FIG. 2 illustrates schematically in a perspective representation the calibration or end sizing of the hollow profile component of FIG. 1.

DETAILED DESCRIPTION

(4) The hollow profile component 100 shown in FIG. 1 is formed from an extruded aluminum rectangular profile. The hollow profile component 100 may have an axial length of, e.g., 1000 mm and it may be installed as a longitudinal or transverse beam in an automobile, e.g., as part of a space-frame bodywork structure. Because of the extruded production, the hollow profile component 100 may have dimensional and shape deviations, e.g., in the form of warping or buckling, so that prior to installing it, especially in regard to the joining technologies used, a calibration or an end sizing is required.

(5) FIG. 2 shows a press tool 200 according to the invention for the calibration of the hollow profile component 100. The press tool 200 installed in a forming press comprises a bottom tool part 210 fashioned as a die, of which only the operative tool surface is shown, and a top tool part 220 fashioned as a punch, of which likewise only the operative tool surface is shown. The design configuration of the die 210 and the punch 220 lies within the competence of the person skilled in the art. Moreover, the press tool 200 includes two expandable mandrels or mandrel sets 230 and 240.

(6) For the calibration, the hollow profile component 100 is inserted into the die 210 of the press tool 200, as shown in FIG. 2. By lowering the punch 220, the press tool 200 is closed, so that the hollow profile component 100 is totally enclosed by the tool cavity, except at its open profile ends 130 and 140. The expandable mandrels 230 and 240 are introduced into the open profile ends 130 and 140 of the hollow profile component 100. By external application of force by means of the punch 220 and by simultaneous internal application of force by means of the expandable mandrels 230 and 240 (which are expanded for this purpose), the hollow profile component 100 is calibrated in its two end regions 110 and 120, determined by the insertion lengths of the mandrels 230 and 240 (for example, 100 mm). The functional geometries 150 and 160 may also be formed in this process. The end sizing and the forming of the functional geometries 150 and 160 occurs in the cold state within a single press stroke. After the expandable mandrels 230 and 240 have been returned to a non-expanded state and retracted from the hollow profile component 100, the press tool 200 can be opened and the calibrated hollow profile component 100 can be removed and further processed.

(7) The bottom tool part 210 and the top tool part 220 form a kind of external tool for the applying of external shaping forces and the two expandable mandrels 230 and 240 form a kind of internal tool for the simultaneous applying of internal shaping forces. The external tool 210/220 and the internal tools 230/240 are coordinated with each other such that the nominal geometry of the hollow profile component 100 can be formed with them. The internal cross sections of the external tool 210/220 and the external cross sections of the internal tools 230/240 are, for example, coordinated with each other such that the respective gap between introduced expanded internal tool 230/240 and external tool 210/220 corresponds to the respective nominal profile of the hollow profile component 100.

(8) The mandrels 230 and 240 each comprise two mandrel jaws 231 and 232 as well as 241 and 242, configured here as top and bottom mandrel jaws 231/232 or 241/242 and able to be forced apart transversely to the longitudinal or axial direction of the hollow profile component 100 with the aid of a first wedge 235 or 245, which can be pushed between them in the longitudinal or axial direction. The first wedges 235 and 245 are activated via exterior sloping surfaces 236 and 246 by means of second wedges 250 and 260, which are coupled, in particular, with the top tool part 220 or the press ram 201. The double V-slide mechanisms make possible a very good adapting of the force and displacement transmission, so that the press tool 200 can also be used in forming presses with slight pressing force. The jaws and wedges are preferably made of a steel material, especially a hardened steel material. The resetting can be conducted by means of spring elements, not shown.