EP1549447A1

EP1549447A1 - Method and device for permanently joining overlapping, plate-shaped parts

Info

Publication number: EP1549447A1
Application number: EP03753483A
Authority: EP
Inventors: Stephan Dietrich; Reinhard Mauermann
Original assignee: Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Current assignee: Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Priority date: 2002-09-30
Filing date: 2003-09-30
Publication date: 2005-07-06
Anticipated expiration: 2023-09-30
Also published as: DE10245604A1; EP1549447B1; WO2004030844A1; AU2003271664A1; US20050229378A1; DE50306401D1

Abstract

The aim of the invention is especially to increase the process security and reliability of permanent connections between overlapping materials. Said aim is achieved by a method for permanently joining overlapping, plate-shaped parts, particularly metal sheets, in which an undercut between the parts is produced in a deforming manner. Said method comprises the following steps: the parts that are to be joined are disposed between a protrusion of a male die and a support area of a female die; a temporary elevation is formed on the side of the parts, which faces the female die, by pressing the protrusion of the male die into the parts that are to be joined and against the support area at least until the parts rise from the support area outside the forming elevation; and an undercut is formed in the parts by flattening the elevation between the male die and the female, the male die being further approached to the female die. Also disclosed is a device for carrying out the inventive method.

Description

Method and device for the permanent connection of overlapping, plate-shaped components

The present invention relates to a method for permanently connecting overlapping, plate-shaped components, in particular sheet metal, by forming an undercut between the components.

In addition, the invention relates to a device for the permanent connection of overlapping, plate-shaped components, in particular sheet metal, by forming an undercut between the components, with a stamping tool that can be moved along a main working direction towards and away from a counter tool.

In the sheet metal processing industry, individual parts are connected by manufacturing processes of mechanical joining technology. In the automotive industry in particular, inexpensive processes are used in which at least two components are connected to one another by plastic deformation of the same without a pre-hole and without the use of additional auxiliary joining parts.

For many years, methods and devices for connecting overlapping, in particular plate-shaped, components have been known from the prior art, in which an undercut connection is produced by local deformation of the components to be joined together. These methods are referred to in the specialist literature as clinching.

In this method, an overlap area of the two or more components to be connected to one another is arranged between a stamping tool and a counter-tool (die). This stamping tool is then pressed directly into the joining area of the (two) components with high force, as a result of which both components are first deep-drawn into a recess formed in the die in the area of the stamping attack, and the base area of the deep-drawn surface parts is then squeezed. The die is designed in such a way that undercuts between the components can form when the bottom area of the deep-drawn surface parts is squeezed. The methods used are differentiated according to the different embodiments of the respective matrices. The use of rigid one-part matrices is known, for example from DE 3532 900 A1, DE 36 13324 A1 or DE 19929 375 A1. In addition, rigid multi-part matrices, for example from DE 3923 18 A1, movable multi-part matrices, for example from DE 31 06 313 A1 or DE 37 13 083 A1 and mixed forms, for example from DE 101 16 736 A1, are known.

Common to all these different methods is the use of a contoured die as a counter tool. The contouring enables deep drawing or penetration of the components to be connected locally by means of a recess into which the material of the components can be molded.

Furthermore, the contouring allows a material flow in the radial direction due to its specific shape or the mobility of individual parts of the die, which leads to the formation of the undercut.

With all such methods, however, an exact axial alignment of the tools with respect to one another, in particular of the die and punch, is absolutely necessary in order to be able to produce quality connections. In practice, this leads to a high level of manufacturing accuracy required for the tools and machines, as well as to the time required to set up these joining devices.

In addition, the joining devices must be designed to be very rigid so that the high forces during the joining process and the resulting bending on the joining devices do not lead to the occurrence of quality-reducing offsets of the tools relative to one another.

The invention is therefore based on the object of providing a method for mechanically connecting plate-shaped components which are at least partially arranged one above the other, with the aid of which secure and high-quality connections of components can be produced more cost-effectively and reliably than previously. Furthermore, the invention is based on the object of improving a device of the type mentioned at the outset in such a way that the requirements for the manufacturing tolerances and for the alignment of the tools of the device can be reduced, so as to increase process reliability.

This object is achieved according to the invention in a method for the permanent connection of overlapping, plate-shaped components, in particular sheet metal, by forming an undercut between the components in one working stroke with the individual steps: arranging the components to be connected between a stamp projection of a stamping tool and a support surface a counter tool, pressing the stamp projection into the components to be connected, forming a temporary elevation on the side of the components facing the counter tool and separating regions thereof outside an area of influence of the stamp projection from a contact surface of the counter tool, and forming an undercut of the components by further reducing one Soil thickness in the survey.

Furthermore, the object for a device of the type mentioned at the outset is achieved according to the invention in that the counter tool is essentially flat on its side facing the stamp tool.

With the invention, it becomes possible, through the interaction of a stamping tool and a counter-tool, to produce permanent connections between at least partially superimposed plate-shaped components, in particular metal sheets, the connection produced having undercut areas that form a geometric interlocking of the components to be connected.

Flat here should be understood to mean essentially “flat” or “plan”.

Due to the flat counter tool, which is preferably designed in the form of a flat anvil, the axial alignment of the anvil and punch with respect to one another is of secondary importance in contrast to the conventional clinching method. The necessary manufacturing accuracy for tools and machines is reduced, as is the time required to set up the joining devices. Offsets that occur during the joining process due to the high forces between the anvil and the punch have little or no influence on the formation of the connection. The process reliability of the method increases because the counter tool is subject to less wear due to its flat shape, and the quality is independent of an exact alignment of the tools to one another.

The connection created has a geometrical undercut area, so that a pretreatment for activating the surface of the joining partners to be joined together is not necessary.

An undercut connection similar to a clinch connection can thus be produced in the present invention. In contrast to traditional clinch connections, the connection is not formed by a deep-drawing process with subsequent squeezing of the bottom area of the deep-drawn surface parts, which require a die with a recess, but by a backward extrusion process, followed by a squeezing of the material remaining under a punch face , the process can be combined with a simultaneous emergence of the neck area.

When the plunger is pressed in, there is a material flow opposite to the plunger movement when the hold-down force is limited, and thus an elevation is formed on the side of the counter tool.

In the further course of the process, only this elevation has contact with the counter tool. When the material pressed out of the plane of the lower plate is squeezed out in this elevation, the undercut is formed by the radial flow of material. The recess of the counter tool, which is usually necessary for the clinching process, is not necessary for the implementation of this process principle.

Subsequent to the formation of the undercut, a further stamp movement can preferably be carried out in the direction of flattening the connection area of the two the workpieces. Attention must be paid to the corresponding force limitation for tool safety.

A wobbling movement of the die to realize the formation of the undercut is not necessary. However, it can be overlaid to reduce the joining forces. Such a superimposed movement can have a circular or a rosette shape.

Furthermore, an additional cyclic force can be superimposed on the active axial feed movement. When using the wobble overlay with rosette shape together with the cyclical force overlay, both overlays are coordinated so that the wobble direction of the stamp and the cyclical additional stamp force are clearly dependent on each other. A specific wobble direction of the punch, preferably when the wobble angle increases to the maximum wobble angle α in the wobble direction outwards, is assigned the maximum superimposition force in order to achieve an optimal material flow.

According to a preferred embodiment, the method according to the invention includes a step of moving a hold-down device towards the counter-tool, and as a result, a defined holding force is exerted on the components during the plastic deformation. Furthermore, an additional step of stabilizing the components by means of a counterholder is conceivable, by means of which the components are urged towards the stamping tool against the direction of movement thereof.

It is possible that the movement of the stamp projection on the counter tool is superimposed with a wobble movement at least during part of the stamp path. The wobble can be circular or rosette-shaped. It is also desirable that the punch, the hold-down device and / or the counter-holder be hydraulically, pneumatically, magnetically, mechanically or piezoelectrically acted upon, the application of force preferably taking place by means of one or more pulses.

It is also conceivable that the application of force takes place during at least part of the stamp path by superimposing an additional cyclical force, with Use of the wobble overlay with a rosette shape or wobble angle of the stamp and the additional cyclical stamp force are clearly coordinated with each other.

According to a preferred embodiment, the application of force to the hold-down device is controlled and increases particularly at a defined point in the movement of the punch. This stops the movement of the components directed against the direction of movement of the stamp and vice versa.

With such a method, it is possible for the movement of the components directed against the direction of movement of the stamp at a defined point of movement of the stamp to be stopped by a stamp shoulder and vice versa. It is also possible that the movement of the components directed against the direction of movement of the stamp is stopped by a direct or indirect mechanical stop of the hold-down device on the stamp and vice versa at a defined point of movement of the stamp. After the formation of the undercut, a tool movement is preferably carried out in the direction of flattening the elevation.

In the case of a device for the permanent connection of overlapping, plate-shaped components, in particular sheet metal, by forming an undercut between the components, in particular for carrying out the aforementioned method, the latter has a stamping tool that points towards and from a counter tool along a main working direction is movable away, with the counter tool on its side facing the stamp tool, at least in the entire area of the stamp tool, in particular a stamp end face and a stamp shoulder, preferably also a hold-down device, being essentially flat. It is desirable here that a main body of the stamping tool has a stamped shoulder on its side facing the counter-tool, from which a stamped shoulder protrudes.

Preferably, at least one main body of the stamping tool is surrounded by a hold-down which is movable relative to the main body. The main body is preferably relative to the hold-down device by means of a prestressing element, in particular re a hold-down spring, biased against a feed direction of the stamping tool.

According to a further preferred embodiment, the main body of the stamping tool can be moved in a wobbling motion at least during part of its movement towards the counter tool. In this case, a stamp face arranged on the stamp shoulder is essentially flat, in particular flat, slightly spherical or slightly conical. In this case, the stamp projection can be designed to be slightly tapered towards the stamp end face.

It is possible that a stamp end face arranged on the stamp shoulder is essentially at right angles to a main working direction or slightly inclined to it. It is also conceivable that a transition from the stamp face to a lateral surface of the stamp projection is designed in the form of a radius or a trailing curve. It is also possible that a transition from the stamp face to a lateral surface of the stamp projection is in the form of a chamfer or a double chamfer.

Here, the shape element forming the transition from the stamp face to the lateral surface is less than 0.2 millimeters. In all embodiments, the counter tool is preferably designed as a one-piece anvil, its side facing the stamp tool being designed as an essentially flat, in particular flat, slightly convex or slightly conical contact surface for the components.

According to a particularly preferred embodiment, the contact surface of the counter tool is larger than the elevation formed on the components, preferably larger than the projection surface of the stamp tool facing it, but in particular of the stamp projection and the stamp shoulder, which can also be formed by the hold-down device. It is desirable that the dimensions of the contact surface of the counter tool be larger or substantially equal to the outer dimensions of the hold-down device.

Both an area of the support surface of the counter tool lying opposite the stamp end face and an area of the support surface of the counter tool opposite the stamp shoulder are preferably essentially on one Main working direction vertical plane. The contact surface is formed free of shoulders or recesses at least in the region of the projection of the stamp face and the stamp shoulder, preferably also of the hold-down device.

In these embodiments, it is conceivable that the anvil of the counter tool is at least partially surrounded by a counter holder which is movable relative to the anvil in the main working direction. This counterholder can be acted upon pneumatically, hydraulically, magnetically, mechanically and / or piezoelectrically with a force which is directed counter to a punch and / or hold-down force.

According to one embodiment, the main body of the stamping tool, the hold-down device, the anvil and / or the counter-holder have circular or annular cross sections. Alternatively, the main body of the stamping tool, the hold-down device, the anvil and / or the counter-holder have a cross-section deviating from a circular shape, in particular an angular cross-section.

Further preferred embodiments of the method and the device are the subject of the respective subclaims.

The invention is explained in more detail below with reference to a schematic drawing, for example and with further details. Show:

Fig. 1 a) - c) a first embodiment of the device according to the invention

Implementation of the method according to the invention, here: FIG. 1a) an initial state,

1 b) an intermediate state, and

1c) a final state after the connection;

2 a) - c) a second embodiment of the device according to the invention with a holding-down device moving on a block when carrying out the method according to the invention, here:

2a) an initial state,

Fig. 2b) an intermediate state, and 2c) a final state after the connection;

3 a) - d) a third embodiment of the device according to the invention with an anvil with spring-loaded outer ring and with a hold-down device moving on a block when carrying out the method according to the invention, here:

3a) an initial state,

3b) a first intermediate state before the stamping die penetration into the components,

3c) a further intermediate state after the formation of a temporary elevation, and

3d) a final state after connecting the components; and

4 shows an alternative embodiment of the device according to the invention with a stamping tool with a tumbling stamp when the method according to the invention is carried out in an intermediate state.

A first exemplary embodiment of the invention will now be explained in more detail with reference to FIGS. 1a) to 1c). In the description of the embodiments, for the sake of clarity, the directions of movement and the relative arrangements of the components are denoted by the terms “above” and “below”, as shown in the figures; it goes without saying that any other spatial arrangement is possible accordingly.

In the exemplary embodiment shown in FIG. 1, an upper component 1 is connected to a lower component 2. In the initial state, as shown in FIG. 1 a, the two components 1, 2 to be connected to one another are arranged on a substantially flat contact surface 3 c of the counter tool 3, preferably a one-piece anvil 3 b.

To establish the connection, a stamping tool 4 with a main body 4e and a hold-down 5 is then moved in the direction of the components 1, 2 along a main working direction A towards the counter tool 3. With the hold-down 5 a defined holding force is exerted on the components 1, 2 by means of raul, pneumatically, piezoelectrically, magnetically or by springs.

A stamp projection 4b is formed on the (lower) side of the main body 4e facing the counter tool 3, the cross section of which is preferably smaller than the cross section of the remaining (upper) part of the main body 4e. A stamp shoulder 4a is formed at the transition, which is preferably flat and orthogonal or flat and slightly (e.g. up to approximately 6 °) inclined to a main working direction A in one plane.

At the beginning of the actual clinching process, the punch projection 4b is then pressed into the components 1, 2 hydraulically, pneumatically, magnetically, piezoelectrically or mechanically with high force. The foremost (lowermost) section of the stamp projection 4b, which is referred to as the stamp end face 4c, penetrates through the cross section of the upper component 1 into the component 2, but without penetrating one of the components, so that in front of the stamp end face during the entire process material of all components to be connected remains.

The respective material of the components 1, 2 to be connected is displaced locally and first moves radially outwards and then in a controlled manner upward from the holding-down device 5 and / or from the stamp shoulder 4a against the direction of movement of the stamp main body 4e.

The components 1, 2 are lifted off the support surface 3c of the counter tool 3 (anvil 3b). By moving the sections of the components 1, 2, which are not clamped between the stamp end face 4c and the bearing surface 3c of the counter tool 3, upward (towards the stamp tool 4) from the pushed-away material of the components, one is formed in the region of the stamp projection 4b Elevation 2a out.

Only in this area there is still contact between the lower component 2 and the anvil 3b on the underside of the lower component 2. 1b shows an intermediate state in which this can be clearly seen. As soon as the material of the upper component 1 has contact with the shoulder 4a of the stamp main body 4e, the further movement of the material of the components 1, 2 to be connected is impeded against the direction of the stamp movement. The elevation 2a formed is therefore reduced in size when the stamping tool 4 is advanced, and the material still located under the end face 4c of the stamp 4 must flow radially outward. As shown in FIG. 1c, an undercut 1a is formed.

The ratio of the cross sections or diameters of stamp projection 4b and stamp shoulder 4a can be selected depending on the strength of the materials to be connected and the joining force such that no lasting impression of the stamp shoulder 4a is caused in the upper component 1.

The stamp projection 4b can be slightly conical in order to ensure that the stamp projection can be simply pulled out of the components 1, 2 which are connected to one another. The stamp end face 4c arranged on the stamp projection 4b is preferably flat, in particular flat, or else slightly spherical or slightly conical.

Here, a transition from the stamp face 4c to a lateral surface 4d of the stamp projection 4b is formed in the form of a radius or a trailing curve; however, the transition from the stamp face 4c to the lateral surface 4d of the stamp projection 4b can also be designed in the form of a chamfer or a double chamfer, in any case preferably the shaped element forming the transition from the stamp face 4c to the lateral surface 4d is less than 0.2 millimeters.

As shown in the figures of the first embodiment, the counter tool 3 is designed as a one-piece anvil 3b, the side facing the stamping tool 4 as a substantially flat, in particular flat, but also as a slightly spherical or slightly conical contact surface 3c for the components 1, 2 is trained.

In this case, in each embodiment, the contact surface 3c of the counter tool 3 is larger than the diameter of an elevation 2a, so that the material of the components 1, 2 cannot be pushed past to the side next to the contact surface. Are preferred the dimensions of the contact surface 3c of the counter tool 3 are larger or substantially equal to the outer dimensions of the hold-down device 5.

A region of the bearing surface 3c of the counter-tool 3 opposite the stamp end face 4c and also a region of the bearing surface 3c of the counter-tool 3 opposite the stamp shoulder 4a lie essentially on a plane perpendicular to the main working direction A, although a slight curvature of the entire surface up or down is conceivable is.

In each of the embodiments, the contact surface 3c is free of shoulders, recesses, depressions, depressions or the like.

It is conceivable that the main body 4e of the stamping tool 4, the hold-down 5, and / or the anvil 3b have circular or annular cross-sections, as well as that the main body 4e of the stamping tool 4, the hold-down 5, and / or the Anvil 3b has a cross-section deviating from a circular shape, in particular an angular cross-section. The individual components are preferably matched to one another, but are also designed to be movable independently of one another.

A second exemplary embodiment of the invention is described below with reference to FIGS. 2a) to 2c). Parts and components that correspond to those described above have the same reference numerals and will only be described again to the extent necessary.

A device for the permanent connection of two or more flat components can be seen in another embodiment in FIG. 2. In the initial state, as shown in FIG. 2a, the (two) components 1, 2 to be connected to one another rest on the flat counter tool 3, here the anvil 3b.

To establish the connection, a stamping tool 4 is moved hydraulically, pneumatically, magnetically, piezoelectrically or mechanically with high force in the direction of the components 1, 2. In this embodiment, the stamp tool 4 has a stamp main body 4e, a hold-down 5, a stamp carrier 6, a hold-down sleeve 7 and a hold-down spring 8.

First, the hold-down 5 is placed on the components 1, 2 to be connected. The hold-down spring 8 is compressed here. Then, the end face 4c of the stamp protrusion 4b of the stamp main body 4e comes into contact with the upper member 1.

The stamp projection 4b is now fully or partially pressed into the components 1, 2. The material of the components 1, 2 to be connected is displaced locally and first moves radially outwards and then in a controlled manner from the holding-down device 5 upward against the direction of movement of the stamping tool 4. Components 1, 2 are lifted off the anvil 3b. Only in the area of the emerging elevation 2a on the underside of the lower component 2 is there still contact between the lower component 2 and the anvil 3b. 2b shows an intermediate state in which this can be clearly seen.

As soon as an upper stop 5a of the hold-down 5 comes into contact with a lower stop 6a of the stamp carrier 6, the further movement of the material of the components 1, 2 to be connected is prevented in the opposite direction to the stamp movement. The elevation 2a formed is therefore reduced in size when the stamping tool 4 is further advanced and the material still located under the end face 4c of the stamping projection 4b of the stamping main body 4e must flow radially outwards.

As shown in FIG. 2c, an undercut 1a is formed. The ratio of the dimensions (or diameter) of the punch face 4c and the underside of the hold-down 5 can be selected depending on the strength of the materials to be connected and the joining force so that no lasting impression of the hold-down 5 is caused in the upper component 1.

A third exemplary embodiment can be seen in FIGS. 3a) to 3d). Parts and components that correspond to those described above have the same reference numerals and will only be described again to the extent necessary. In an initial state, as shown in FIG. 3a, the (two) components 1, 2 to be connected to one another rest on a preferably spring-loaded or otherwise pressurized counter-holder 3a (outer ring) of an anvil 3b of the counter-tool 3.

To establish the connection, the hold-down 5 and the main body 4e of the stamping tool 4 are moved in the direction of the components 1, 2. The hold-down 5 is used hydraulically, pneumatically, piezoelectrically, magnetically, mechanically or in another way, in particular e.g. by springs, a defined force on the components 1, 2 and on the counter-holder 3a. The force with which the hold-down device 5 is acted upon is preferably selected to be greater than the counteracting force of the counter-holder 3a.

As a result, as shown in FIG. 3b, the counter-holder 3a is pushed back until the components 1, 2 to be connected are placed on the anvil 3b. The stamp projection 4b is then, as described above, pressed into the components 1, 2 with high force. The material of the components 1, 2 to be connected is displaced locally and moves first radially outwards and then controlled by the hold-down device 5 as well as by the counter-holder 3a upward against the direction of movement of the stamping tool 4. This results in the components 1, 2 being lifted off the anvil 3b.

Only in the region of the elevation 2a that forms on the underside of the lower component 2 is there still contact of the lower component 2 with the contact surface of the counter tool 3, the anvil 3b.

In contrast to the exemplary embodiments already described, the material moving in opposition to the punch movement is no longer prevented from moving by the entire holding-down force, but only by the difference in the forces acting on the holding-down device 5 and the counter-holding device 3a. As a result, with minimal hindrance to the lifting of the components 1, 2 from the anvil 3b, high holding forces can be applied which prevent the components 1, 2 from bending or the formation of a gap between the components. It is conceivable that the counter-holder 3a has a circular or circular cross-section, as well as that the counter-holder 3a has a cross-section that deviates from a circular shape, in particular an angular cross-section. The individual components (main body 4e of the stamping tool 4, hold-down 5, anvil 3b and counter-holder 3a) are preferably matched to one another, but are also designed to be movable independently of one another.

A further intermediate state is shown in FIG. 3c. As soon as the material of the upper component 1 has contact with the shoulder 4a of the stamp main body 4e, the further movement of the material of the components to be connected is prevented in the opposite direction to the stamp movement. The elevation 2a formed is therefore reduced in size when the stamping tool 4 is further advanced, and the material still located under the end face 4c of the stamping projection 4b must flow radially outward. As shown in FIG. 3d, an undercut 1a is formed.

Due to the high force with which the hold-down device 5 can be acted on in this exemplary embodiment without the connection process being impaired, the joined components 1, 2 are easily stripped from the punch projection 4b after the joining process when the tools 3, 4 are moved apart.

The ratio of the cross-sections (diameter) of the stamp face 4c and the stamp set 4 can, depending on the strength of the materials to be connected and the joining force, again be chosen such that no permanent impression of the stamp shoulder 4a in the upper component 1 is caused.

In this exemplary embodiment, too, no high accuracies are required with regard to the coaxiality from the stamping tool 4 to the counter tool 3, since the counter holder 3a has no part in the formation of the connection and only takes on a holding task. In order to achieve high forces with short travel, both the hold-down 5 and the counter-holder 3a can already be preloaded in the initial state.

An alternative (fourth) embodiment, the teaching of which can be combined with each of the previously described embodiments (as well as the first three embodiments with one another) is shown in FIG. It is shown here that the stamp main body 4e of the stamping tool 4 can also have a wobble movement with a maximum wobble angle α between the main working direction A and an axis B of the stamp main body 4e superimposed on it to reduce the force.

It is important here that, as described in the exemplary embodiments already explained, the force of the holding-down device 5 is dimensioned such that a deflection of the components 1, 2 to be connected or a gap formation between the two components 1, 2 is largely avoided, but at the same time a formation of the elevation 2a and thus a movement of the components 1, 2 opposite to the axial movement of the main stamp body 4e is made possible. A counter-holder 3a, as shown in the third exemplary embodiment, can be provided for this.

As soon as the material of the upper component 1 comes into contact with the shoulder 4a of the stamp main body 4e, the further movement of the material of the components 1, 2 to be connected is impeded against the direction of the stamp movement. The elevation 2a formed is therefore reduced in size when the stamping tool 4 is further advanced and the material still located under the, preferably conical, end face 4c of the stamp main body 4 must flow radially outward. As described in the other exemplary embodiments, an undercut is formed.

The ratio of the diameter of the stamp end face 4c and stamp shoulder 4a can in turn be selected depending on the strength of the materials to be connected and the joining force such that no permanent impression of the stamp shoulder 4a is caused in the upper component 1.

It goes without saying that more than two components can also be connected to one another using the method according to the invention and the device according to the invention. It is also clear that the counter tool can also or exclusively be designed as a moving component. The arrangement of the tools in the room is also arbitrary. It is also conceivable to effect a plurality of connections at the same time. The geometric contour of the tools and the joints can essentially be selected as desired.

All elastically deformable materials, in particular sheets and plastics, are conceivable as the material for the components to be joined. The individual components can also consist of different materials.

Claims

claims:

1. Method for the permanent connection of overlapping, plate-shaped components (1, 2), in particular of sheet metal, by forming an undercut (1a) between the components (1, 2) in one working stroke with the individual steps:

Arranging the components (1, 2) to be connected between a stamp projection (4b) of a stamp tool (4) and a contact surface (3c) of a counter tool (3),

• Pushing the punch projection (4b) into the components (1, 2) to be connected, forming a temporary elevation (2a) on the side of the components (1, 2) facing the counter tool (3) and separating areas thereof outside an area of influence of the Stamp projection (4b) from a support surface (3c) of the counter tool (3), and

• Forming an undercut (1 a) of the components (1, 2) by further reducing a base thickness in the elevation (2a).

2. The method according to claim 1, characterized by a step of moving a hold-down device (5) towards the counter tool (3), and thereby exerting a defined holding force on the components (1, 2) during the plastic deformation.

3. The method according to at least one of claims 1 or 2, characterized by an additional step of stabilizing the components (1, 2) by means of a counter-holder (3a), through which the components (1, 2) against the direction of movement of the stamping tool (4) be pushed towards this.

4. The method according to at least one of claims 1 to 3, characterized in that the movement of the stamp projection (4b) on the counter tool (3) is superimposed with a wobble movement at least during part of the stamp path, the wobble movement preferably being circular or rosette-shaped he follows.

5. The method according to at least one of claims 1 to 4, characterized in that the stamp (4), the hold-down (5) and / or the counter-holder (3a) hydraulic be applied forcefully, pneumatically, magnetically, mechanically or piezoelectrically, wherein the force is preferably applied by means of one or more pulses.

6. The method according to claim 5, characterized in that the application of force takes place during at least part of the stamp path by superimposing an additional cyclic force, the wobble angle of the stamp and the additional cyclical stamp force being coordinated with one another in a clear dependence on one another when using the wobble superimposition with a rosette shape ,

7. The method according to at least one of claims 5 or 6, characterized in that the application of force to the hold-down device (5) takes place in a controlled manner and in particular increases sharply at a defined point of movement of the stamp (4) and thereby counter to the direction of movement of the stamp (4 ) directed movement of the components (1, 2) stops and reverses, or that the movement of the components (1, 2) directed against the direction of movement of the stamp (4) at a defined point of movement of the stamp (4) by a stamp shoulder ( 4a) is stopped and vice versa, or that at a defined point of movement of the punch (4) the movement of the components (1, 2) directed against the direction of movement of the punch (4) by an indirect or direct mechanical stop (6a) of the hold-down device (5) is stopped at the stamp and vice versa.

8. The method according to at least one of claims 1 to 7, characterized in that, following the formation of the undercut (1a), a tool movement takes place in the direction of flattening the elevation (2a).

9. Device for the permanent connection of overlapping, plate-shaped components (1, 2), in particular sheet metal, by forming an undercut (1a) between the components (1, 2), in particular for carrying out a method according to claim 1, with: a stamping tool (4) which can be moved towards and away from a counter tool (3) along a main working direction (A), characterized in that the counter tool (3) on its Tool (4) facing side is substantially flat.

10. The device according to claim 9, characterized in that a main body (4e) of the stamping tool (4) on its side facing the counter-tool (3) has a heel (4a) from which a stamped shoulder (4b) protrudes.

11. Device according to one of claims 9 or 10, characterized in that at least one main body (4e) of the stamping tool (4) is surrounded by a hold-down device (5) which is movable relative to the main body (4e), preferably the main body (4e) is biased relative to the hold-down device (5) by means of a biasing element, in particular a hold-down spring (8), against a feed direction of the stamping tool (4).

12. The device according to at least one of claims 9 to 11, characterized in that the main body (4e) of the stamping tool (4) can be moved in a wobbling movement at least during part of its movement towards the counter-tool (3).

13. The device according to at least one of claims 9 to 12, characterized in that a stamp end face (4c) arranged on the stamp shoulder (4b) is essentially flat, in particular flat, slightly spherical or slightly conical, preferably the stamp projection (4b). is slightly tapered towards the stamp face (4c).

14. The device according to at least one of claims 9 to 13, characterized in that a stamp end face (4c) arranged on the stamp shoulder (4b) is substantially at right angles to a main working direction (A) or slightly inclined to it.

15. The device according to at least one of claims 9 to 14, characterized in that a transition from the stamp face (4c) to a lateral surface (4d) of the stamp projection (4b) is designed in the form of a radius or a trailing curve, or a transition from the Stamp end face (4c) to form a lateral surface (4d) of the stamp projection (4b) in the form of a chamfer or a double chamfer is in any case preferably the shape element forming the transition from the stamp end face (4c) to the outer surface (4d) is less than 0.2 millimeters.

16. The device according to at least one of claims 9 to 15, characterized in that the counter tool (3) is designed as a one-piece anvil (3b), the side facing the stamping tool (4) as a substantially flat, in particular flat, slightly convex or slightly tapered support surface (3c) for the components (1, 2) is formed, the support surface (3c) of the counter tool (3) preferably being larger than the elevation (2a) formed on the components (1,2).

17. The apparatus according to claim 16, characterized in that the dimensions of the support surface (3c) of the counter tool (3) are larger or substantially equal to the outer dimensions of the hold-down device (5) and / or that the support surface (3c) is free of paragraphs or Recesses is formed.

18. The device according to at least one of claims 16 or 17, characterized in that both an area of the support surface (3c) of the counter tool (3) opposite the stamp end face (4c) and an area of the support surface (3c) opposite the stamp shoulder (4a) of the counter tool (3) lie essentially on a plane perpendicular to the main working direction (A).

19. The device according to at least one of claims 16 to 18, characterized in that the anvil (3b) of the counter tool (3) is at least partially surrounded by a counterholder (3a) which is relative to the anvil (3b) in the main working direction (A) Can be moved, wherein preferably the counter-holder (3a) can be applied pneumatically, hydraulically, magnetically, mechanically and / or piezoelectrically with a force which is directed against a punch and / or hold-down force.

20. The device according to at least one of claims 9 to 19, characterized in that the main body (4e) of the stamping tool (4), the hold-down (5), the anvil (3b) and / or the counter-holder (3a) circular or annular Have cross sections, or that the main body (4e) of the stamping tool (4), the never the holder (5), the anvil (3b) and / or the counter-holder (3a) have a cross-section deviating from a circular shape, in particular an angular cross-section.