Device and method for producing at least partially closed profiles or tubular components from metal sheet

Abstract

The invention relates to a device and method for producing at least partially closed profiles from metal sheet, having a first tool part, a second tool part, and at least one supporting core. The insertion movement of the supporting core between the bending jaws is limited by a stop and, in its insertion position limited by the stop, protrudes with respect to the bending jaws in the direction of the die, in that the supporting core is arranged on a carrier that is movable relative to the die, and in that the bending jaws are assigned at least one displacement element connected rigidly thereto, the displacement element coming into contact with the carrier when the bent metal sheet portion engages around the supporting core.

Claims

1. A device for producing at least partially closed profiles or tubular components from a metal sheet, the device comprising: a first tool part having a die, a second tool part having bending jaws and at least one supporting core, which is insertable between the bending jaws in contact with a cut-to-size metal sheet portion formed in a U-shape, wherein the insertion movement of the supporting core between the bending jaws is limited by a stop defined by an inner shoulder of the bending jaws and the supporting core, in its insertion position limited by the stop, protrudes in the direction of the die in relation to the bending jaws, the supporting core being arranged on a carrier that is movable relative to the die, and the bending jaws being assigned at least one displacement element rigidly connected thereto, which touches the carrier when the bent metal sheet portion engages around the supporting core, and, upon continued movement of the bending jaws in the direction of the die, displaces the carrier and/or the carrier is moved so that the profile or component formed from the metal sheet portion is introducible into the die for the purpose of its calibration and/or compression with the supporting core, wherein the carrier is provided with a guide supporting the supporting core, said guide having at least two guide portions, which are spaced apart from one another and in which channel-shaped guide paths that align with one another are configured to receive the supporting core, the die being arranged between the two guide portions.

2. The device according to claim 1, wherein arranged between the bending jaws is a movable pressure piece, which is moved with the supporting core upon bending of the metal sheet portion by means of the bending jaws, the pressure piece preferably being resiliently mounted and preferably being displaced by the supporting core.

3. The device according to claim 2, wherein the bending jaws and the displacement element(s) are connected to one another by a head plate.

4. The device according to claim 3, wherein the head plate has bores or openings to guide guide pins connected to the pressure piece.

5. The device according to claim 1, wherein the carrier is resiliently supported on a base plate by means of a large number of spring elements, preferably lower air pins.

6. The device according to claim 5, wherein downwardly protruding spacer elements are provided on the lower side of the carrier.

7. The device according to claim 1, wherein it is configured as a follow-on composite tool for a follow-on composite press.

8. The device according to claim 1, wherein the supporting core has two, three or more portions with a different cross-sectional shape, the diameter of the cross-sectional shape in the case of three or more portions increasing step-wise or continuously from a smallest diameter to a largest diameter, and the bending jaws limiting a recess which receives the supporting core with a metal sheet portion resting thereon and is widened step-wise or continuously in accordance with the supporting core.

9. The device according to claim 1, wherein a second supporting core is present, which is symmetrical with the first supporting core or has a different cross-sectional shape to the first supporting core.

10. The device according to claim 9, wherein the second supporting core has two, three or more portions with a different cross-sectional shape, the diameter of the cross-sectional shape in the case of three or more portions increasing step-wise or continuously from a smallest diameter to a largest diameter, and the bending jaws limiting a recess which receives the second supporting core with a metal sheet portion resting thereon and is widened step-wise or continuously in accordance with the second supporting core.

11. The device according to claim 1, wherein it is configured as a double tool or double follow-on composite tool for the simultaneous forming of two at least partially closed profiles or two tubular components.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be described in more detail below with the aid of drawings showing embodiments, in which, schematically:

(2) FIG. 1 and FIG. 2 show an embodiment of a device according to the invention in a perspective view and in a side view, respectively;

(3) FIG. 3 is a sectional view of the device along the section line III-Ill of FIG. 2 with a metal sheet portion that is preformed in a U-shape;

(4) FIG. 4 to FIG. 6 are sectional views of the device during various instants when a method according to the invention is being carried out to produce an at least partially closed profile or tubular component from metal sheet;

(5) FIG. 7 shows the device in a perspective view at the instant according to FIG. 6;

(6) FIG. 8 shows the device in an open state in a sectional view with the completely formed profile or component;

(7) FIG. 9 shows a strip-like or band-like metal sheet, in which sheet portions to be formed are cut free, preformed or formed to form a closed profile (tubular component), in a perspective view; and

(8) FIG. 10 shows a device according to the invention, which is configured as a follow-on composite tool for a follow-on composite press, and a strip-like or band-like metal sheet according to FIG. 9, in a perspective view.

DETAILED DESCRIPTION OF THE INVENTION

(9) FIGS. 1 and 2 show an embodiment of a device according to the invention for producing at least partially closed profiles or tubular components from metal sheet. The device will be, or is, integrated in a follow-on composite press, in which blank-like workpieces 2 are initially cut free from a strip-like or band-like metal sheet 1 by means of stamping tools (not shown) or the like (see FIGS. 9 and 10).

(10) The workpieces (blanks) 2 that have been cut free remain connected to the strip-like or band-like metal sheet 1 by two connecting webs 3 during their forming in the device according to the invention. The connecting webs 3, which remain on the sides of the respective workpiece 2 running transversely to the transporting direction of the metal sheet band 1, can be separated from the metal sheet band 1 after conclusion of a calibration of the component 2 formed by bending or optionally only after welding of the longitudinal edges 4 of the respective tubular component 2.

(11) Before entry into the device according to the invention, the front and rear edge regions 2.1, 2.2, viewed in the transporting direction, of the blank 2 connected to the metal sheet band 1 are bent, so the blank 2 then has a substantially U-shaped cross-sectional shape as the preform. The bent edge regions 2.1, 2.2 of the blank 2 are relatively narrow here. Placed next to one another they together form one side, for example a base 2.3, of the hollow profile (component) 2 to be produced.

(12) The blank 2 connected to the metal sheet band 1 and preformed in this manner is then formed into an at least partially closed profile or tubular component 2 in the device according to the invention by means of bending jaws 5.1, 5.2 and at least one supporting core 6 that is insertably positionable between the bending jaws.

(13) The device according to the invention, which can also be called a follow-on composite tool, comprises a first tool part having a die 7, a second tool part having the bending jaws 5.1, 5.2 and the at least one supporting core (slider) 6. The bending jaws 5.1, 5.2 arranged at a specific spacing from one another define a gap 8, in which the supporting core 6 can be inserted in contact with the sheet portion 2 that has been cut free and has been preformed in a U-shape.

(14) The bending jaws 5.1, 5.2 are attached or releasably fastened to a head plate 9. The gap (hollow space) 8, which is limited by the bending jaws 5.1, 5.2 and into which the supporting core 6 can be inserted, passes into a narrower gap (hollow space) 10. The insertion movement of the supporting core 6 is limited by the shoulder defining a stop 11 between the wider gap 8 and the narrower gap 10.

(15) A pressure piece (die inlay, holding-down device) 12 is arranged between the bending jaws 5.1, 5.2, said pressure piece preferably being resiliently mounted or supported on the head plate 9. The pressure piece 12, on insertion of the supporting core 6 into the wider gap 8 defined by the bending jaws 5.1, 5.2, is displaced therefrom into the narrower gap 10. The gap 8 and the supporting core 6 are dimensioned such that the supporting core protrudes in the direction of the die 7 relative to the bending jaws 5.1, 5.2 in its insertion position limited by the stop 11 (cf. FIG. 5). The pressure piece 12 can also be actively activated or driven by other current means, for example by hydraulic and/or pneumatic means.

(16) The pressure piece 12 is provided with a row of pins (bolts) 13 spaced apart from one another, which are guided in a sliding manner in bores or openings 14, which are introduced adjacent to the narrower gap 10 between the bending jaws 5.1, 5.2 into the head plate 9.

(17) The supporting core 6 is arranged on a carrier 15. The carrier 15 is plate-like or frame-like and preferably resiliently mounted on a base plate 16. The carrier 15 may, however, also be actively controlled or driven by other current means, for example by hydraulic and/or pneumatic means.

(18) The carrier 15 is provided with a guide 17 supporting the supporting core 6. The guide 17 is, for example, formed from to guide portions 17.1, 17.2, which are spaced apart from one another and in which channel-like guide paths 18.1, 18.2 that align with one another are configured to receive the supporting core 6. One (17.1) of the guide portions is substantially longer here than the other guide portion 17.2. The length of the longer guide portion 17.1 preferably corresponds at least to the length of the supporting core 6 (see FIGS. 1 and 2). The length of the guide channel 18.2 of the shorter guide portion 17.2 is a fraction of the length of the supporting core 6 or of the guide channel 18.1 of the longer guide portion 17.1, for example less than of the length of the longer guide portion 17.1.

(19) The plate-like or frame-like carrier 15 is preferably resiliently supported on the base plate 16 by means of a large number of lower air pins 19 or alternative suspension elements. The carrier 15 can also be called a spring base. Attached to the resiliently mounted carrier 15 are spacer elements 20, which protrude in relation to the lower side thereof in the direction of the base plate 16. The carrier 15 has a window-like recess 15.1, which surrounds the die 7 mounted on the base plate 16 with play. The die 7 is arranged between the two guide portions 17.1, 17.2 and preferably releasably mounted on the base plate 16. The carrier (spring base) 15 is thus movable relative to the die 7 with the supporting core 8 held thereon in the guide 17.

(20) The head plate 9 is provided with displacement elements 21 on its lower side next to the bending jaws 5.1, 5.2. The displacement elements (displacers) 21 are preferably pin-like or bolt-like. When the follow-on composite tool according to the invention is closed, the displacement elements 21 touch the carrier 15, which is preferably resiliently mounted on the base plate 16, or the guide portions 17.1, 17.2, which are connected to the carrier and hold the supporting core 6.

(21) The mode of functioning of the follow-on composite tool according to the invention will be described below with the aid of FIGS. 3 to 8.

(22) FIG. 3 shows a starting position, in which the follow-on composite tool is open, in that the upper tool part has been moved up relative to the lower tool part. The strip-like metal sheet 1 is located with the sheet portion 2, which has been cut free and has been preformed in a U-shape and which is still integrally connected to the strip-like metal sheet 1 by means of connecting webs 3 (cf. FIG. 9), in the working region of the tool, the strip-like metal sheet 1 being raised to a specific transporting height. The supporting core 6 provided with a drive (not shown) is located in a drawn-back position on the larger portion 17.1 of the guide 17. The preferably spring-loaded pressure piece (die inlay) 12 is located in the wider gap 8 defined by the bending jaws 5.1, 5.2 and protrudes slightly in relation to the end faces 5.3, 5.4 of the bending jaws 5.1, 5.2 facing the die. The spring base (carrier) 15 with the supporting core 6 guided thereon is in its raised position maximally spaced apart from the base plate 16.

(23) FIG. 4 shows a situation in which the supporting core 6 is moved below the preformed sheet portion 2 so the supporting core 6 rests on the two portions 17.1, 17.2 of the guide 17 and bridges the window-like recess 15.1 of the plate-like carrier 15. The strip like metal sheet 1 has been lowered onto a working plane, so the preformed sheet portion 2 rests on the supporting core 6. In addition, the upper tool part has been lowered, so the preformed sheet portion 2 is clamped between the supporting core (slider) 6 and pressure piece (die inlay) 12. The counter-pressure exerted by the lower air pins 19 (or the corresponding counter-force) is greater than the force required to bend the preformed sheet portion 2 plus the force exerted by the pressure piece 12.

(24) FIG. 5 then shows the situation, in which the preformed sheet portion 2 has been bent, in that the upper tool part has been lowered to such an extent that the supporting core 6 with the sheet portion 2 is inserted in the gap (hollow space) 8 between the bending jaws 5.1, 5.2 and rests on the stop 11 defined by the bending jaws. At the same time, the pressure piece 12 clamping the sheet portion 2 has been displaced into the upper, narrower gap (hollow space) 10. The guide elements 13 connected to the pressure piece 12 now protrude in relation to the upper side of the head plate 9. Furthermore, the displacement elements (displacers) 21 have been placed, in this situation, on the guide 17 and therefore on the preferably resiliently mounted carrier 15. The longitudinal edges 4 of the slot profile 2 thus produced face one another on the lower side of the supporting core 6. The longitudinal edges 4 may touch one another here or be spaced apart from one another by a very narrow slot 22.

(25) If the upper tool part is further lowered relative to the situation shown in FIG. 5, the displacement elements (displacers) 21, with displacement of the lower air pins 1.9 or compression of corresponding alternative spring elements, press against the guide 17 and therefore against the carrier 15. The carrier 15 is, or can be, displaced to such an extent in the direction of the base plate 16 until the spacer elements 20 bear on the base plate 16. In this case, the at least partially closed profile 2 with the supporting core 6 arranged therein is pressed into the recess 7.1 of the die 7 and thereby compressed or calibrated (see FIGS. 6 and 7). Not only is an uncontrolled springback counteracted in his manner but internal stresses in the component 2 can also thus be minimised.

(26) The upper tool part is then raised again, the lower air pins 19 (or similar spring elements) pushing the carrier 15 back into its starting position.

(27) Finally, the situation is shown in FIG. 8, in which the tool according to the invention is again located in its starting position. The supporting core (slider) 6 is moved back out of the working region and frees the tubular component or slot profile 2 produced, which is still connected by the connecting webs 3 to the strip-like metal sheet 1 (cf. FIG. 10).

(28) The longitudinal edges 4 of the slot profile 2 are welded to one another in a butt joint into a closed hollow profile in a following process step, a laser welding device (not shown) preferably being used for this. The components 2 produced in this manner are preferably used as structural components in vehicle construction, for example as closed profiles for bumpers, so-called crash boxes, longitudinal beams, transverse beams, seat carrier profiles etc. The longitudinal edges 4 can optionally also be welded at a later instant in a separate device.

(29) The implementation of the invention is not limited to the embodiments shown in the drawings and described above. Rather, numerous variants are conceivable, which, even with a configuration differing from the examples shown, make use of the invention disclosed in the accompanying claims. Thus, the method according to the invention also, for example, comprises embodiments, in which two supporting cores 6 are used, which have different cross-sectional shapes and are brought together from opposing sides and are moved apart after the forming of the profile or component. Furthermore, the method according to the invention also, for example, comprises embodiments, in which at least one of the supporting cores 6 has two, three or more portions with a different cross-sectional shape, the diameter of the cross-sectional shape, in the case of three or more portions of the supporting core, increasing step-wise or continuously from a smallest diameter to a largest diameter, and the bending jaws 5.1, 5.2 limiting a recess which receives the supporting core 6 with a metal sheet portion 2 resting thereon and is widened step-wise or continuously in accordance with the supporting core 6.