DE29700868U1 - Push through device - Google Patents

Description

■*■ Avdel Fasteners GmbH, Klusriede 24, D-30581 Langenhagen

Device for clinching.

The present invention relates to a device for joining overlapping sheet metal parts with a punch and an anvil on which at least two die parts are supported in a laterally movable manner, which delimit an opening, so that when the punch moves into the opening they move laterally when the sheets are deformed, thus creating a

joining point is formed.
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The problem with all previously known methods and devices for clinching is that the undercut of the punch-side sheet metal at the anvil-side outer edge of the joining point must be as strong as possible so that the joining point achieves the required strength.

The devices for clinching according to the state of the art OQ technology (for example U.S. Patent 4,910,853) previously had an anvil that had a diameter only slightly larger than the punch. The anvil was surrounded by the die parts that were elongated in the direction of movement of the punch and that were spread apart from the anvil during the backflow process by which the undercut was formed. However, this meant that the material of the joining point could be removed.

flow downwards along the outside of the anvil. The undercuts therefore remained relatively small and the strength of the joining point was insufficient.

In order to remedy this problem, multi-stage clinching processes have already been proposed in the prior art, in which the joining point is compressed again after clinching. However, this multi-stage clinching can only be implemented with a very complicated device and requires a large number of work steps.

It is therefore an object of the present invention to provide a device for clinching which achieves better strength of the joining points without additional equipment expenditure in the joining device and without additional processing steps.

This object can be achieved according to the invention in that the anvil has a surface facing the punch which supports at least the entire surface over which

the joining point at the end of the joining process.
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It is particularly preferred to produce the die parts from L-shaped bent spring steel sheet parts, one leg of the L extending over the surface of the anvil facing the punch, while the other leg runs parallel to the anvil and is attached to the anvil at the distal end. In this way, the particularly thin die required for the device according to claim 1 can be realized most easily.

It is also preferred to design the anvil in the shape of a cuboid and to provide two die parts on opposite side surfaces of the cuboid. In this way, the construction of the die becomes particularly simple and economical.
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Furthermore, it is also preferable to design the anvil in the shape of a cuboid and to arrange a die part on each of the four sides of the cuboid. This ensures that the die opening widens as evenly as possible during the backflow process.

Furthermore, the object of the invention can be achieved by separating the die parts by gaps that do not run radially. According to the state of the art, radial gaps were always provided between the die parts. During the backflow process, the die parts must move outwards. This creates gaps between the die parts.

parts into which the material could escape, so that at these points a proper backflow process did not take place and these areas did not contribute to the strength of the joint.
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To solve this problem, it is particularly preferred that the joints run obliquely to the radial direction.

If the opening of the die has a circular cross-section, it is particularly preferred to arrange the joints tangentially to it.

It is particularly preferred if the opening of the die has a circular cross-section and the joints are in the form of inwardly curved arches, so that the

Opening like an iris diaphragm. With this solution, no gaps are created at all and this results in a uniform undercut process over the entire circumference of the joint point. The undercut is equally strong and firm everywhere. Particularly good results can of course be achieved by combining the features of claims 1 to 4 and 5 to 8.

Q The present invention will now be explained in more detail with reference to the embodiments shown in the drawings.

FIGURE 1 shows a single-stage clinching device without cutting component according to the prior art;

FIGURE 2 shows a joining point produced with the device according to Figure 1;

FIGURE 3 shows a single-stage clinching device according to the invention without cutting portion with enlarged anvil;

FIGURE 4 shows a device produced with the device according to Figure 3.

joining point;

FIGURE 5 shows an anvil-die arrangement according to the invention in perspective view;

FIGURE 6 the arrangement of Figure 5 in sectional view cut perpendicular to the joint;

FIGURE 7 shows another anvil-die arrangement according to the invention in perspective view;

FIGURE 8 shows a matrix part of Figure 7 in perspective view;

FIGURE 9 shows a matrix arrangement with radially extending joints according to the prior art in the closed state;

FIGURE 10 shows the arrangement of Figure 9 in the open state (during the backflow process);

FIGURE 11 shows a joining point produced with the matrix arrangement according to the prior art according to Figure 9 in top view;

FIGURE 12 is a section along the line a-a of Figure 11; FIGURE 13 is a section along the line b-b of Figure 11;

FIGURE 14 shows a matrix arrangement according to the invention in "iris diaphragm form" in the closed state;

FIGURE 15 the arrangement of Figure 14 in opened state

(during the backflow process);

FIGURE 16 shows another matrix arrangement according to the invention in iris diaphragm form made of only two parts and

FIGURE 17 shows the die arrangement of Figure 16 mounted on the anvil in a sectional view.

For a better understanding of the present invention, Figure 1 first shows the function of a clinching device

according to the prior art (for example U.S. Patent 4,910,853). Figure 1 shows the state at the end of the backflow process. The punch 10 is lowered as far as possible onto the anvil 12. The die parts 14, 16 are pressed apart as far as possible so that the two sheets 18, 20 to be joined are already beginning to flow downwards over the side edges of the anvil 12.

This flow process is shown in detail in Figure 2, where the arrows A indicate the flow direction of the material. As shown in Figure 2, this process creates an undercut of depth d _x . The strength of a joining point depends essentially on the size of this undercut U ₁ ,

Figure 3, on the other hand, shows a clinching device according to the invention, in which the anvil 112 is considerably wider 20

than the punch 10. This device is also shown during a joining process at the time of completion of the backflow process. As can be clearly seen in Figure 3, the material cannot be pushed around the side edges of the anvil.

because it is considerably wider. The matrix parts 114, 116, which are of course made thinner here, are also opened to the maximum.

0 Figure 4 shows the resulting joining point, whereby in this case the arrows B indicate the flow direction. As can be clearly seen, this flow direction in the device according to the invention points horizontally to the side (arrows B in Figure 4), while in Figure 2 the arrows A point sideways downwards at about 45°. As can be clearly seen in Figure 4, this creates a much wider undercut d ₂ . The joining point is therefore

point according to Figure 4 is considerably stronger than the joining point according to Figure 2.

Figure 5 shows an anvil-die arrangement according to the invention, as can be used in Figure 3, for example. The anvil 112 is essentially cube-shaped. Its edge length is greater than the maximum diameter of the joining point. The two die parts 114, 116 consist of L-shaped spring steel angles, which enclose the opening 117 for the joining point between them. The other legs of the L-shaped die parts are connected at their distal end, i.e. away from the edge, to the side surface of the anvil by riveting or screwing.

For further explanation, Figure β shows a corresponding sectional view through the matrix-anvil arrangement according to the invention in Figure 5.

Figure 7 shows another die-anvil arrangement according to the invention, in which the die is formed by four L-shaped spring steel angles 213, 214, 215, 216. These are

then divided diagonally so that the opening 217 is bordered by all four die parts. The attachment to the anvil body corresponds to the arrangement in Figure 5.

For further illustration, a single die element 213 is shown in Figure 8.

To understand the further solution according to the invention with the "iris-shaped" matrix arrangement, the state of the art is again shown in Figures 9 to 13.

Figure 9 shows a currently common matrix arrangement consisting of

• ···« m 9 »

four matrix elements 313, 314, 315, 316 separated by radial joints 300, each forming a quarter circle.

Figure 10 shows the same arrangement in the open state, i.e. at the end of the backflow process, when the matrix elements 313, 314, 315, 316 are pushed apart as far as possible by the flow of the joining point.

Figure 11 shows a joining point produced with the die device according to Figures 9 and 10, in plan view. It is clearly visible that the joining point is not completely round, but has recesses caused by the gap 300 at the points where the individual die elements 313 to 316 abut one another.

As can be seen from Figures 12 and 13, these recesses lead to a
of the joining point.

measurements lead to a significant reduction in strength

Figure 12 shows a section through the joining point of the fi-

gur 11 along the line a-a. As can be seen, the undercut is good there and the joining point therefore appears to have good strength values.

However, if one cuts along the line b-b of Figure 11, as shown in Figure 13, whereby the cut then runs through the recesses of the joining point formed by the gap 300, one can see from Figure 13 that almost no undercut has been formed here. These areas of the joining point therefore do not contribute to the strength. The joining point produced according to the state of the art therefore lacks

a significant part of the theoretically achievable maximum strength.

In order to remedy this disadvantage, the present invention teaches that the corresponding gaps 300 should not run radially (in the flow direction of the backflow process). A particularly preferred embodiment is shown in Figure 14. Here, the gaps 400 between the individual die elements 413 to 416 are curved so that no gaps can form even when the die is pushed open by the backflow process, since the individual die elements 413 to 416 can move apart without forming gaps, as shown in Figure 15.

Since no gaps can form between the individual matrix elements in this solution according to the invention, a simplified arrangement according to Figure 16 with only two

matrix elements 414, 416. Of course, this arrangement also works with a different number of matrix elements. With more than five matrix elements,

However, the construction would be too complex.
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Figure 17 shows a sectional view of the die-anvil arrangement for a die shape according to Figure 16. The anvil 412 is also wider than the maximum width of the joining point. The L-shaped die elements 414 and 416 are attached to the side surfaces of the anvil. They are held in their position by a spring ring 420 so that they can move and elastically spring back.

The present invention enables a considerably higher productivity through a relatively simple modification of the anvil-die arrangement.

Better strength of the joining points can be achieved without the need for additional work steps in the clinching process.

Claims (8)

Beautiful Brose & ßrose Dipl.-!ng. Kar! A, Brose j 21.01.1997 Dipl.-Ing. D. Karl Brcse Dipl.-ing. Alexander Beck Be-au Poetf. 1164 - Leutstetlenöf Str. ^3 D-82301 Siarnberg Te». 08151 /72412 - Fsx -/72712 Avdel Fasteners GmbH, Klusriede 24, D-30851 Langenhagen PROTECTION CLAIMS 1. Device for the clinching of overlapping sheet metal parts, with a punch and an anvil on which at least two die parts are laterally movably supported, which delimit an opening so that they move laterally when the punch moves into the opening when the sheets are deformed and a joining point is thus formed, characterized in that the anvil (112) has a surface facing the punch (10) which supports at least the entire area over which the joining point extends at the end of the joining process. 2. Device according to claim 1, characterized in that the die parts (114, 116; 213, 214, 215, 216) consist of L-shaped bent spring steel sheets, which extend with one leg of the L over the surface of the anvil (112) facing the punch (10), while the other leg runs parallel to the anvil (112) and at the distal end is attached to the anvil (112). 3. Device according to claim 2, characterized in that the anvil (112) is cuboid-shaped and two die parts (114, 116) are provided on opposite side surfaces of the cuboid. 4. Device according to claim 2, characterized in that the anvil (112) is cuboid-shaped and a die part (213, 214, 215, 216) is arranged on each of the four side surfaces of the cuboid. 5. Device for joining overlapping sheet metal parts, with a punch and an anvil on which at least two die parts are supported in a laterally movable manner, which delimit an opening so that they move laterally when the punch moves into the opening when the sheets are deformed and a joining point is thus formed, characterized in that the die parts (413, 414, 415, 416) separated by joints (400) which do not run radially. 6. Device according to claim 5, characterized in that the joints (400) run obliquely to the radial direction.
25 7. Device according to claim 6, characterized in that the opening (417) of the die has a circular cross-section and the joints (400) run tangentially thereto. 8. Device according to claim 5, characterized in that the opening (417) of the die has a circular cross-section and the joints (400) run in the form of inwardly curved arches so that the opening can open like an iris diaphragm.