Flanging device for pre-flanging and flanging of components

The present invention pertains to a hemming device according to the preamble of patent claims 1 and 2 .

“Hemming” is defined as the positive-locking connection of two parts by folding over a flange. Especially an outer sheet metal and an inner sheet metal are connected to one another hereby in the manufacture of vehicle bodies.

For example, the following systems are available for the hemming of body parts:

1. Hemming tools which are used in presses and perform the prehemming or finishing hemming of the flange by a vertical movement of the upper part of the tool. Such a hemming process has been known from DE 44 18 684 A1, where a slide moves radially inwardly and subsequently again radially outwardly for the prehemming and a second hemming tool is displaced vertically by means of the press punch for the finishing hemming. Special efforts are needed for feeding and removing the components due to the arrangement of the press above the folding bed. Above all, the upper tool must perform a long stroke.

2. Hemming devices in which the hemming bed is stationary and the flange to be hemmed is bent over by hydraulically or electrically operated slides or mechanical rocker arm elements. The actuation and operation of the hemming slides and the rocker arm element are complicated (cf. DE 197 47 292 C1).

3. A hemming device of this class has been known from U.S. Pat. No. 5,150,508, in which the lower folding bed, on which the sheet metals to be connected are placed, performs a separate hemming stroke for the prehemming and the finishing hemming and presses in the process the flange to be folded one after another against the stationary prefolding jaws and finishing folding jaws. The prefolding and finishing folding jaws are arranged rigidly on a horizontally displaceable slide. The folding bed must be displaced vertically and the folding jaws horizontally for the prefolding and the finishing folding. The folding bed must then perform a long displacement travel between the prefolding operation and the finishing folding operation and the hemming stroke proper in the particular positions.

The basic object of the present invention is to propose a device of this class, in which the vertical movement of the folding bed is limited to a minimum and the prefolding and finishing folding jaws are brought into position by secure and simple movements.

To accomplish this object, it is proposed that the prefolding jaw is also displaceable from the outside to the inside into the prehemming position by means of a slide and relative to the slide of the finishing folding jaw.

As an alternative to the displaceability of the prefolding jaw, it is proposed according to the present invention that the prefolding jaw is fastened to a pivoting plate and can be pivoted from the outside to the inside into the prehemming position by actuating the pivoting plate, and that the pivoting plate can be locked with the prefolding jaw fastened to it in the prehemming position. Meaningful embodiments for this are shown in the subclaims 3 through 10 .

Due to the fact that the folding jaws can be displaced according to the present invention on slides of their own possibly independently from one another into the hemming position above the folding bed for the prefolding and the finishing folding, the displacement travel of the folding bed can be considerably reduced. The prefolding and finishing folding jaws can be brought one after another into the same hemming position especially if the guide paths of the two slides are arranged at acute angles in relation to one another, so that a long adjustment movement of the folding bed between the prefolding and the finishing folding is not necessary. Consequently, the folding bed performs only the hemming stroke proper each time for the prefolding and the finishing folding, and this hemming stroke takes place at one and the same point. The same is also possible in the alternative embodiment, the combination of the pivotable prefolding jaw with the displaceable to finishing folding jaw.

It proved to be favorable to arrange the slide for prefolding or the pivoting plate on the slide for finishing folding or vice versa. In this so-called piggyback arrangement or slide-on-slide arrangement, the displacement travels for the individual slides are limited to a minimum. In addition, an especially compact design is possible. A spring actuated holding-down device, which fixes the two sheet metals on the surface of the folding bed already before the beginning of the prefolding and finishing holding operation, may be arranged on the upper slide, preferably the slide for the prefolding or on the pivoting plate.

It proved to be favorable in the alternative embodiment according to the present invention to mount the drives for the slide with the finishing folding jaw and the pivoting plate on a common bracket in an articulated manner, wherein the bracket itself is rigidly connected to the base. Moreover, the pivoting plate may be mounted on another bracket, which is likewise rigidly connected to the base or to the slide, in a rotatingly movable manner via an additional hinge.

The pivoting plate can be locked in the working position by a locking unit, which is brought into the locked position by a movement of the slide for the finishing folding with the existing drive unit being arranged on the slide for the finishing folding. However, the pivoting plate and the slide may also be coupled with one another such that the prefolding and finishing folding jaws can be forcibly moved one after another into the working position with a common drive unit. It proved to be favorable in this connection to arrange stops at the pivoting plate and the slide, which are brought into contact for locking the prefolding jaws. The pivoting plate can then be pivoted upwards by means of a connecting link guide present at the slide for the subsequent finishing folding. Only one drive unit is necessary here for the linear movement of the slide, because the pivoting plate is inevitably also actuated at the same time with the movement of the slide.

The present invention will be explained in greater detail on the basis of FIGS. 1 through 7 attached. In the drawings,

FIG. 1 shows a side view of a detail of the slide-on-slide arrangement,

FIG. 2 shows a sectional view for FIG. 1 in the so-called zero position,

FIG. 3 shows a corresponding sectional view in the prefolding position,

FIG. 4 shows a sectional view in the finishing folding position,

FIG. 5 shows a side view of a detail of the combination of the pivoting plate and the slide in the prefolding position,

FIG. 6 shows the pivoted-back position of the pivoting plate for FIG. 5, and

FIG. 7 shows an embodiment for the actuation of the pivoting plate and the slide with a drive unit.

The figures show the outer edge of a folding bed 4 with the outer edges of the body sheets 5 and 6 , which outer edges lie on the said outer edge. For hemming, e.g., an automobile door, a folding bed 4 is arranged under the entire door. The folding bed 4 with the sheets 5 , 6 lying on it is raised with the hemming stroke and pressed one after another against the oblique contact surface 14 of the prefolding jaw 9 and against the horizontal contact surface 15 of the finishing folding jaw 10 for the two-step folding over of the upright flange 7 with the exception of the flat edge area 8 . As is apparent from FIG. 1, the lower slide 2 is displaceable for the finishing folding on a base 1 on horizontal guide paths 19 . The drive 12 for the slide 2 is supported on the frame 1 via the fastening 11 . On the side facing the folding bed 4 , the finishing folding jaw 10 is detachably fastened to the lower slide 2 , e.g., by a screw connection. The upper slide 3 is displaceable on the slide 2 for prefolding on the guide paths 20 in the direction of the double arrow shown. The guide paths 20 are arranged at an acute angle, preferably at an angle of 25° in relation to the guide paths 19 . The drive 13 for the slide 3 is supported on the slide 2 via the fastening 16 . The prefolding jaw 9 is preferably fastened detachably to the slide 3 .

In the zero position shown in FIG. 2, the upper slide 3 with the prefolding jaw 9 and the lower slide 2 with the finishing folding jaw 10 are in the retracted position The folding bed 4 with the components 5 and 6 is lowered into the lower end position. The holding-down device 17 fastened to the upper slide 3 is held in the extended lower position by the spring 18 or in some other way.

In the prefolding position according to FIG. 3, the slide 2 with the finishing jaw 10 is in the zero position. The slide 3 with the prefolding jaw 9 moves by about 50-60 mm at an angle of 25° in relation to the horizontal direction and can be locked by means of toggle levers, not shown, or in some other way. The holding-down device 17 is in the extended position under the force of a spring. The folding bed 4 moves upward into the hemming stroke, while the sheet 6 is fixed in its position by the holding-down device 17 by the force of a spring. The flange 7 is brought into an approximately 45° position during the hemming stroke by the oblique contact surface 14 of the prefolding jaw 9 . After the conclusion of the prefolding operation, the folding bed 4 moves downward by the hemming stroke and the slide 3 returns into the zero position.

In the finishing folding position according to FIG. 4, the slide 3 with the prefolding jaw 9 is in the zero position. The slide 2 with the finishing folding jaw 10 moves to the stop. The holding-down device 17 is in the extended position under spring force. The folding bed 4 moves upward by the hemming stroke, while the sheet 6 is fixed in its position by the holding-down device 17 by spring force. After the conclusion of the folding operation, the folding bed 4 moves downward by the hemming stroke and the slides 2 and 3 return into the zero position.

The hemming device according to the present invention makes possible a substantial reduction of the vertical movements of the folding bed 4 . This happens due to the fact that the prefolding and finishing jaws are brought one after another into the same folding position by means of a hydraulic, pneumatic or electric drive.

In the views in FIGS. 5 and 6, the prefolding jaw 21 is rigidly connected to the pivoting plate 24 . The pivoting plate 24 is mounted on the bracket 28 in a rotatingly movable manner by means of the hinge 26 , on the one hand, and, on the other hand, it is pivoted by means of the drive 22 . The drive 22 is connected via the hinge 25 to the pivoting plate 24 and via another hinge to the bracket 23 which is fastened to the base 1 . In the prefolding position according to FIG. 5, the pivoting plate 24 is secured by means of the locking mechanism 29 . The locking mechanism 29 arranged rigidly on the slide 2 is moved to and fro together with the slide 2 by actuating the drive 12 . According to FIG. 6, the bracket 28 is rigidly connected to the base 1 . To make possible a relative movement between the slide 2 and the bracket 28 , the slide 2 is provided with an elongated hole in the area of the hinge 26 .

In the embodiment according to FIG. 7, only one drive unit 30 , which moves the slide 2 linearly to and fro, is provided, contrary to the embodiment according to FIGS. 5 and 6, instead of the two drive units 12 and 22 . To lock the prefolding jaw 21 in the prefolding position being shown, a lower stop 32 is fastened to the slide 2 and an upper stop 33 is fastened to the pivoting plate 24 . When the slide 2 is moved to the left in the view by means of the drive unit 30 after the conclusion of the prefolding, the connecting link guide 31 arranged rigidly on the slide 2 is also moved at the same time, and the pivoting plate 24 fastened to the bracket 28 is moved with the roller 34 in the connecting link guide 31 such that the prefolding jaw 21 is pivoted upward in the process.

The process is essentially as follows in the “slide-on-slide” system:

1. Transfer of the components 5 , 6 to the folding bed 4

2. The upper slide 3 with the prefolding jaw 9 moves forward into the folding position

3. The folding bed 4 with the components 5 , 6 lying on it moves upward against the prefolding jaws 9 (prefolding)

4. The folding bed 4 with the prefolded flange 7 moves into the lowermost position

5. The upper slide 3 moves back

6. The lower slide 2 with the finishing folding jaw 10 moves forward into the folding position

7. The folding bed 4 with the components 5 , 6 lying on it moves upward against the finishing folding jaws 10 (finishing folding)

8. The folding bed 4 with the finished folded component moves into the lowermost position

9. The lower slide 2 moves back

10. The finished folded component is removed.

The process is essentially as follows in the “pivoting plate and slide” system:

1. Transfer of the components 5 , 6 to the folding bed 4

2. Pivoting of the prefolding jaws 21 into the prefolding position

3. Forward movement of the slide 2 to lock 29 the prefolding jaws 21 (see FIG. 5)

4. The folding bed 4 with the components 5 , 6 lying on it moves upward against the prefolding jaws 21 (prefolding)

5. The folding bed 4 with the prefolded flange 7 moves into the lowermost position

6. The slide 2 moves back to unlock the prefolding jaws 21

7. Pivoting back of the pivoting plate 24 into the position according to FIG. 6

8. The slide 2 with the finishing folding jaws 10 moves forward into the finishing folding position

9. The folding bed 4 with the component lying on it moves upward against the finishing folding jaws 10 (finishing folding)

10. The folding bed 4 with the folded component moves into the lowermost position

11. The slide 2 moves back

12. The finished folded component is removed.

The process is as follows for the system according to FIG. 7 :

1. The slide 2 is in the intermediate position, the pivoting plate 24 is pivoted up

2. The components are transferred to the folding bed 4

3. The slide 2 with the connecting link guide 31 moves back, the prefolding jaw 21 is pivoted in downward, automatic locking by the stops 32 and 33 (see FIG. 7)

4. The folding bed 4 with the components 5 , 6 lying on it moves upward against the prefolding jaws 21 for prefolding

5. The folding bed 4 with the prefolded components moves into the lowermost position

6. The slide 2 moves forward until the prefolding jaw 10 is in the finishing folding position; pivoting up of the prefolding jaw 21 at the same time

7. The folding bed 4 with the prefolded component lying on it moves upward against the finishing folding jaws 10 for the finishing folding

8. The folding bed 4 with the finished folded component moves into the lowermost position

9. The slide 2 moves back into the intermediate position

10. The finished folded component is removed.

1 Base

2 Lower slide (for finishing folding)

3 Upper slide (for prefolding)

4 Folding bed

5 Lower component, body sheet

6 Upper component, body sheet

7 Upright flange of 5

8 Flat edge area of 6 (horizontal)

9 Prefolding jaw

10 Finishing folding jaw

11 Fastening for 12 to 1

12 Drive for 2

13 Drive for 3

14 Contact surface on 9 (oblique)

15 Contact surface on 10 (horizontal)

16 Fastening for 13 to 2

17 Holding down device

18 Spring

19 Horizontal guide path of 2

20 Oblique guide path of 3

21 Prefolding jaw

22 Drive for 21

23 Bracket for 12 and 22 on 1

24 Pivoting plate

25 Hinge between 22 and 24

26 Hinge between 24 and 28

27 Elongated hole in 2 for 26

28 Bracket on 1

29 Locking mechanism on 2 for 21

30 Common drive unit for 2 and 14

31 Connecting link guide (rigidly attached to 2 )

32 Stop, lower (rigidly attached to 2 )

33 Stop, upper (rigidly attached to 24 )

34 Roller on 24