EP2060336B1 - Tool for cutting and flanging flat workpieces - Google Patents

Description

The invention relates to a tool for modesty and flanging of flat workpieces according to the preamble of claim 1.

In the manufacture of vehicle body parts planar sheet metal plates or boards are brought into their actual component form by deep drawing. In a subsequent cutting process, the waste wreath arising during deep drawing is separated off at the component circumference. Subsequently, the edge of the component can be bent by an angle in a bending or crimping operation, whereby a form-locking connection with another component is made possible.

From the DE 39 01 703 C1 a deep-drawing tool is known in which a sheet metal blank is deep-drawn into a predetermined component shape. The tool has a Faltehhalter, which cooperates as a cutting and flanging jaws with a Gegenschneideiement against which the workpiece is pressed by the crimping and cutting jaws during the cutting process.

From the JP 07032057 A is a tool according to the preamble of claim 1 is known.

The invention is based on a cutting and flanging tool for a flat workpiece, in particular a drawn part, which is between a stamp and a hold-down is fixed and has a crimping and cutting jaws, which is guided in relation to the fixed workpiece in a working direction on the workpiece. The crimping and cutting jaws are assigned a counter cutting element, against which the workpiece presses during the cutting operation of the crimping and cutting jaws. The counter-cutting element is supported by a support element, such as a spring base, with which the counter-cutting element after the cutting process is coupled in a movement-coupled manner with the crimping and cutting jaws in the working direction.

Usually, the cutting and flanging operations are technically complex with separate cutting and flanging tools in different steps.

The object of the invention is to provide a cutting and flanging tool or a cutting and flaring method in which workpiece flanges of different sizes can be folded in a simple and reduced-component manner, and in the good operating conditions good vagina and flare results achieved are.

The object is solved by the features of claim 1. Advantageous developments of the invention are disclosed in the subclaims.

According to the invention therefore crimping and cutting jaws are performed in the cutting process relative to the support member to each other adjustable. In the crimping process, however, the crimping and cutting jaws and the counter-cutting element are guided past the workpiece as a movement-coupled composite in order to stop or edge off the workpiece side flange.

For a motion-coupled adjustment movement of the above-mentioned composite of crimping and cutting jaws and counter cutting element of the Crimping and cutting jaws on a tool upper part and / or the support element of the counter cutting element in the working direction or flanging be movable. Preferably, the trimming and flanging of the workpiece can be carried out in successive steps. In terms of manufacturing technology, it is preferred in this case if the crimping process is carried out only after the cutting process. In this way it is prevented that the not yet trimmed workpiece side flange is folded in the crimping, which can lead to a disadvantageous further material extension of the side flange.

A coupling element or spacer element can be provided between a tool part carrying the crimping and cutting jaws and the support element of the counter-cutting element. After the cutting operation, the spacer formed about the tool part can be brought into abutment with the support element of the counter cutting element. In the case of a further flanging movement taking place after the cutting operation, the supporting element of the counter-cutting element is thus carried along with the crimping and cutting jaws in a motion-coupled manner.

For a proper cutting operation, the tool support surfaces of the punch and the counter cutting element can be aligned flush with each other. The workpiece can thus be fixed stress-free between the hold-down and the punch, without resulting in a deformation of the lying on the counter cutting element workpiece side flange due to a height offset.

Preferably, in the cutting operation of the cutting and flanging jaws can be fixed fixed to one, in particular upper tool part. The upper tool part can move downward with a cutting force in the working direction, while the counter cutting element with a counter force against the Working direction is acted upon. For a favorable cutting result, it is preferred if, during the cutting process, the tool bearing surfaces are aligned flush with each other, as already described above. This is inventively achieved in that the punch is guided in the working direction movable on a second tool part.

The loaded with the counter force support member of the counter-cutting element may have a driver which raises the movable punch against the working direction by a vertical distance during the cutting operation. This ensures that the two tool support surfaces of the punch and the counter cutting element remain aligned flush with each other.

The flanging process can - as well as the cutting process - done in the same direction. During the crimping process, the composite of counter-cutting element as well as crimping and cutting jaws can be guided in a motion-coupled manner. Here, the punch is guided together with the composite against a movement stop of a second or lower tool part, while the motion-coupled composite of the crimping and cutting jaws and the counter-cutting element is continued in the working direction. As a result, the crimping and cutting jaws with its crimping edge are guided past the workpiece side flange and bent at the edge of the die accordingly.

To increase the dimensional stability, it may be advantageous if an insertion gap is provided between the punch and the counter-cutting element, can enter in the cutting process of crimping and cutting jaws. In this case, the crimping and cutting jaws can be supported transversely to the working direction between the punch and the counter-cutting element. The crimping and cutting jaws can in this case have separate cutting and flanging edges. The cutting edge may be spaced from the punch over a cutting distance, while the flanging edge may be provided in a transverse direction to the working direction within the cutting distance. It can project beyond the hold-down and the punch laterally and rest on the counter-cutting element with a fixed workpiece to be cut off and abzustellende workpiece side flange.

The hold-down device may preferably press the workpiece against the punch in the upper tool part with a holding force. Both the holding force and the counteracting force exerted by the counter cutting element can be constant during the cutting and crimping process. As a result, the workpiece is held on the punch both during the cutting process and during the flanging process, without impairing a flanging movement or cutting movement of the punch.

Hereinafter, an embodiment of the invention with reference to the accompanying figures is shown.

Fig. 1 und 2

in einer Gesamtseitenansicht sowie in einer vergrößerten Einzelheit das erfindungsgemäße Schneide- und Bördelwerk- zeug bei durch einen Niederhalter fixiertem Werkstück;

Fig. 3 und 4

entsprechende Ansichten des Werkzeugs zur Veranschau- lichung des Schneidevorgangs;

Fig. 5 und 6

jeweils Ansichten zur Veranschaulichung des nach dem Schneidevorgang erfolgenden Bördelvorgangs; sowie

Fig. 7

in vergrößerter Querschnittsansicht den Schneid- und Bördel- backen.

Show it:

Fig. 1 and 2

in an overall side view and in an enlarged detail the cutting and flanging tool according to the invention with workpiece fixed by a hold-down;

3 and 4

corresponding views of the tool to illustrate the cutting process;

FIGS. 5 and 6

each views to illustrate the taking place after the cutting process crimping; such as

Fig. 7

in an enlarged cross-sectional view of the cutting and flanging jaws.

In the Fig. 1 a cutting and flaring tool is shown having an upper tool part 1 and a lower tool part 3. In the upper tool part 1, a hold-7 is slidably mounted in the vertical direction by means of pressure pin 5. The hold-7 is opposite a punch 9, which is provided in the lower tool part 3. Between the hold-down 7 and the punch 9 is fixed as a workpiece to be machined, a sheet metal part 11, which has already been deep-drawn in a previous process step in a deep-drawing tool, not shown. In the Fig. 1 presses the hold-down 7 with a hold-down force F _1, the sheet metal part 11 against the punch. 9

The sheet metal part 11 is folded in the cutting and flanging tool. In addition, a peripheral material waste ring is separated from the sheet metal part 11.

The punch 9 is mounted movably in the tool lower part 3 by a vertical distance a. I'm in the Fig. 1 shown fixing state of the punch 9 is raised by the vertical distance a by means of a later described annular support member 13 and pressed with a counter force F ₂ against the hold-7.

The stamp 9 rests on a support base 14 of the lower tool part 3 and is surrounded radially on the outside by the annular support element 13, on which a counter cutting element 15 is seated, which is provided with an opposite, on cutting tool 1 provided cutting and crimping 17 cooperates.

The support element 13 is designed here as a so-called spring base. This is acted upon by an air cushion, not shown, via pressure pin 18 with the vertically upward opposing force F ₂ . The support member 13 has on its lower side a trained as an inner ring collar 21 driver on which the punch 9 is supported and with which the punch 9 is vertically movable upwards. The support member 13 may also drive in a vertical movement downwards with its annular collar 21 on the outside over the support base 14 of the lower tool part 3.

When a force is applied to the support member 13 by the pressure pin 18, the support element 13 engages under its annular collar 21, the vertically movable punch 9 and lifts it in the in the Fig. 1 shown starting position.

Like from the Fig. 2 shows, provided on Tragelemt 13 counter-cutting element 15 is radially spaced from the punch 9 via an insertion gap 23. During the cutting process, a projection 25 of the cutting and flanging jaws 17 is retracted into the insertion gap 23. The gap width b is dimensioned such that the opposing gap walls with the projection 25 of the cutting and crimping jaws 17 are in sliding contact and support this dimensionally stable.

Like from the Fig. 2 shows, the crimping and cutting jaws 17 at its projection 25 a spaced over a cutting distance c from the punch 9 cutting edge 27 on. At its side facing the hold-down device 7, the projection has a flanged edge 29.

In the Fig. 7 the crimping and cutting jaws 17 is shown in the cross-sectional profile. The integrally formed on the projection 25 of the crimping and cutting jaw 17 cutting edge 27 runs at an acute angle α in the working direction I at an angle. The clearance angle α is enclosed between a horizontal and a free surface 28 facing in the working direction I, which extends in the radial direction over a width d. The free surface 28 is followed by a profile S-shaped back 30 back. The back of the jaw 30 merges with the crimping edge 29, which is rounded off by a crimping radius r, into the crimping surface 32 of the crimping and cutting jaw 17 facing the downholder 7.

The following describes the cutting operation performed by the tool and the subsequent flanging operation. In the Fig. 1 and 2 the sheet metal part 11 is shown in its fixed state in which the punch 9 presses the sheet metal part against the hold-down 7 via the support element 13 and the pressure bolts 18. The hold-down 7 exerts the oppositely directed holding force F ₁ . The tool support surfaces 31 and 33 of the punch 9 and the counter cutting element 15 are according to the Fig. 2 horizontally flush with each other to ensure a stress-free support of the sheet metal part 11 on the punch 9 and the counter-cutting element 15.

To carry out the cutting process, the upper tool part 1 is acted upon by a cutting force F ₃ . As a result, the upper tool part 1 moves together with the cutting and flanging jaws 17 in the working direction I down. At the same time the punch 9 displaces the hold-down 7 against its holding force F ₁ vertically upward. The projection 25 of the cutting and crimping jaw 17 is used in the cutting process with a small cutting path e (FIG. Fig. 4 ) in the insertion gap 23 between the punch 9 and the counter cutting element 15 retracted. The cutting path e is kept comparatively small, whereby a total of the length of the Projection 25 of the cutting and crimping can be kept reduced. Due to the reduced length of the projection 25, this can be designed with a comparatively low material thickness, that is to say approximately the gap width b, and nevertheless its dimensional stability can be maintained. Due to the low material thickness of the projection 25 according to the invention even side flanges can be folded with a small wall height.

As can be seen from the figures, spacers 35 are provided on the upper tool part 1, which in the starting position according to the Fig. 1 are spaced from the designed as a spring base support member 13. In the cutting process, the spacer elements 35 are moved together with the upper tool part 1 in the working direction I down and come the spacer elements 35 into abutment with the support member 13th

The tool upper part 1 moving downwards in the working direction I with the cutting force F ₃ displaces the supporting element 13 acted upon by the counterforce F ₂ downwards. In this way, the tool upper part 1 is moved together with the hold-down 7, the punch 9 and the support member 13 as a motion-coupled composite in the working direction I down until the punch 9 touches on the support base 14 of the tool base 3, as shown in the Fig. 5 is shown.

After placing the punch 9 on the support base 14 of the lower tool part 3, which is acted upon by the upper tool part 1 with the force F _{3 support member} 13 dissolves with its annular collar 21 from the punch 9. This allows the sitting on the upper tool part 1 cutting and flaring jaws 17 pass with its flanged edge 29 on the workpiece side flange 41 and this edge.

As described above, the cutting and crimping jaw 17 and the counter cutting element 15 are guided in the working direction I in a motion-coupled manner to edge the workpiece flange 41.

This movement coupling prevents the cutting and crimping jaw 17 from traveling against a stationarily supported counter cutting element 15 during its crimping movement in the working direction I. In order to avoid a collision with the cutting and crimping jaws 17 in the case of such a counter-cutting element 15 fixedly arranged during the crimping process, the cutting and crimping jaws 17 would have to be disadvantageously provided with an additional insertion recess into which the counter-cutting element 15 can retract. In this case, however, would inevitably increase the free height of the projection 25, which would significantly reduce its dimensional stability.

Claims (14)

1. Tool for cutting and flanging a flat workpiece (11), in particular a drawn part, comprising a first tool part (1) and a second tool part (3), a punch (9) and a hold-down (7), between which the workpiece (11) can be fixed, and comprising a flanging and cutting jaw (17) which is movable in a working direction (I) with respect to the fixed workpiece (11) and has an associated counter-cutting element (15), on which the workpiece (11) rests during the cutting operation and which is supported by a supporting element (13), with which the counter-cutting element (15), after the cutting operation has been carried out, can be guided in the working direction (I) in such a way as to be motionally coupled to the flanging and cutting jaw (17), characterized in that the punch (9) is movably guided on a second tool part (3) in the working direction (I), and the supporting element (13) has a driver (21) which lifts the movable punch (9) from the second tool part (3) against the working direction (I) with a counter force (F₂) during the cutting operation, wherein the second tool part (3) has a motion stop (14) for the punch (9), which the punch (9) strikes during a movement in the working direction (I), while the supporting element (13) can continue to be guided in the working direction (I).
2. Tool according to Claim 1, characterized in that the supporting element (13) of the counter-cutting element (15) is movable in the working direction (I).
3. Tool according to Claim 1 or 2, characterized in that, during a movement of the flanging and cutting jaw (17) in the working direction (I), the flanging operation takes place after the cutting operation.
4. Tool according to Claims 1 to 3, characterized in that the flanging and cutting jaw (17) is motionally uncoupled from the counter-cutting element (15) during the cutting operation, and the flanging and cutting jaw (17) forms a motionally coupled combination together with the counter-cutting element (15) during the flanging operation.
5. Tool according to one of the preceding claims, characterized in that a coupling element or distance element (35) is provided between a tool part (1) supporting the flanging and cutting jaw (17) and the supporting element (13) of the counter-cutting element (15), by means of which coupling element or distance element (35) the tool part (1) shifts the supporting element (13) in the working direction (I) for carrying out the flanging operation after the cutting operation has been carried out.
6. Tool according to one of the preceding claims, characterized in that the flanging and cutting jaw (17) can be moved with a cutting force (F₃) in the working direction (I) against the counter-cutting element (15) during the cutting operation.
7. Tool according to Claim 6, characterized in that the tool part (1) supporting the flanging and cutting jaw (17) shifts the supporting element (13) in the working direction (I) via the distance element (35) after the cutting operation.
8. Tool according to one of the preceding claims, characterized in that the tool bearing surfaces (31, 33) of the punch (9) and of the counter-cutting element (15) are oriented in a flush manner for the cutting operation.
9. Tool according to one of Claims 6 to 8, characterized in that, during the flanging operation, which follows the cutting operation, the flanging and cutting jaw (17) motionally coupled to the counter-cutting element (15) can be guided further in the first working direction (I), in particular vertically downwards.
10. Tool according to one of the preceding claims, characterized in that an insertion gap (23) into which the flanging and cutting jaw (17) can be inserted during the cutting operation is provided between the punch (9) and the counter-cutting element (15).
11. Tool according to one of the preceding claims, characterized in that, when the workpiece (11) is fixed between the hold-down (7) and the punch (9), a side flange, to be cut off or folded, of the workpiece (11) projects laterally beyond the hold-down (7) and the punch (9) .
12. Tool according to one of the preceding claims, characterized in that the flanging and cutting jaw (17) has a cutting edge (27) and a flanging edge (29).
13. Tool according to Claim 12, characterized in that the cutting edge (27) is at a distance from the punch (9) via a cutting gap (c), and the flanging edge (29) is arranged in a transverse direction to the working direction within the cutting gap (c).
14. Tool according to one of the preceding claims, characterized in that the hold-down (7) in the tool part (1) is acted upon by a holding force (F₁) which is less than the counterforce (F₂) exerted by the counter-cutting element (15) and oriented in the opposite direction.

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