ES2457498T3 - Device for joining work pieces - Google Patents

Abstract

Device for joining a first workpiece (1) and a second workpiece (2) with a first tool (5) presenting a first contour (5.1) and with a second tool (6) presenting a second contour (6.1), between which the first workpiece (1) and the second workpiece (2) can be superimposed on a forming plane (3), the first contour (5.1) being pressed against each other and the second contour (6.1) through a forming zone (4) and at least one radiation source (7) to provide electromagnetic radiation that serves to heat the work pieces (1, 2) between the tools (5, 6), characterized in that - laterally to the tools (5, 6), at least, in each case, a radiation source (7) is respectively arranged, such that its electromagnetic radiation is directed respectively on the part working (1, 2) directed to the rad source iation (7) and the forming area (4) and - each of the radiation sources (7) is formed by at least one emitter of direct irradiation diodes, each radiation source (7) being formed by diode emitters of direct irradiation arranged annularly around the tool (5, 6).

Description

Device for joining work pieces

The invention relates to a device for joining work pieces according to the preamble of claim 1, as is known generically by DE 10 2004 062 896 B4.

Increasingly, the increasing demand for construction pieces and light constructions is taken into account and, despite this, stable through the use of high-strength materials. In the field of steel development, in recent years a plurality of developments have been made that allow steels with resistances well above 1000 N / mm2 to be produced and used in series manufacturing products, for example, in automobiles.

However, with the increase in resistance in steels and metallic materials in general, the fluidity and, therefore, the dilatability, that is, a dilation that ends with a breakage, due to the stresses of the flow that

15 grow enormously a narrow limit is set that can be found even at less than 5%.

For further processing of metallic materials, for example, in the form of sheets as shaped pieces or as semi-finished products (work pieces), this means that the materials can be deformed only slightly and then only with very high forces. If such work pieces are welded (fusion welding), the material melts. After solidification of the melt, the weld bead is produced. In the welding bead and in a zone of thermal influence limiting with the welding bead, a change in the structure of the materials of the work pieces welded to each other is produced by melting. Such structure changes most of the time reduce the resistance or energy absorption capacity of the weld bead compared to areas of the workpieces without structure changes.

25 If the work pieces have a coating, for example, aluminum coatings on work pieces hardened in the press, remains of the coatings may be distributed in the weld bead and influence fatigue resistance.

In the case of the application of mechanical joining procedures, work pieces are formed, for example, in a forming plane, forming a positive and / or non-positive joint closure. An example is the cold strain joint, in which two overlapping work pieces are deformed in such a way that a positive and non-positive bond between the two is produced. For this it is necessary that the materials of the work pieces have a minimum dilatability. If it is too low, a brittle breakage occurs during forming. To the

At the same time, tools can be damaged due to the appearance of forces that are too large. For this reason, materials such as, for example, Usibor® are currently not considered suitable for bonding.

Mechanical procedures do not cause changes in the thermal cause structure, however, with high resistance, for example, in the case of more than 600 MPa and, therefore, the appearance of high flow tensions, they reach their limits of use when a bonding process at the same time deformations are required.

In order to cause a reduction in the flow stress of the materials, the forming is thermally supported, that is, the work pieces before forming. Therefore, there is enough energy in the materials to induce displacement movements caused by deformation and enable a plastic deformation without the appearance of

45 brittle breakage. A change of the structure at temperatures of up to 900 ° C is not considered harmful in this regard.

In a procedure according to DE 10 2004 062 896 B4, they are joined together with two positive joints

or several metal work pieces when they are formed with thermal backup through a forming area. For this there are at least two tools that can be pressed together with a compression force. The work pieces limit each other in a plane of forming between the tools and are irradiated with electromagnetic radiation from a laser light source, in such a way that thermal activation or heating of the work pieces through the area is achieved of forming. In this regard, electromagnetic radiation is directed through a transparent material for electromagnetic radiation in at least one of

55 the tools on the forming area.

In this solution it is disadvantageous that there must be a passage or passage inside the tool to house the transparent material for electromagnetic radiation. Therefore, the production of the tool is complicated and high costs. In addition, the strength of the tool and the size of a focal spot in which the electromagnetic radiation in the forming plane on a workpiece is reproduced can not be easily adapted to the changed requirements of the joining process. .

A solution according to US 2003/0037428 A1 works without a passage. In it, electrodes are assigned to the tools. If the tools are brought into contact with the work pieces to be joined, a current can flow into the work pieces, for example, through the forming area between the electrodes and through the electrically conductive work pieces. As a consequence of the flow of current

the forming zone is heated. The tools, to house the electrodes as well as for their electrical isolation, are designed in a complicated way and are weakened in their resistance.

From WO 02/062499 A1 it is known that a radiation source that emits a radiation can be

5 arranged next to the tools. Cylinders are used as tools by means of which a flat workpiece can be formed without chip removal until a profile is given. Through the radiation source, for example, a laser radiation is directed to a focal spot on the surface of the workpiece. The focal spot is generated in an area of a cylinder inlet, that is, in front of the forming zone itself, whereby unwanted heat losses appear.

The invention is based on the objective of proposing a device with tools that can be produced in a simple way, that can be adapted easily to changed requirements of the joining process.

The objective is achieved by a device for joining a first workpiece and a second piece

15 according to claim 1, the device presenting a first tool having a first contour and a second tool having a second contour. Between the tools, the first work piece and the second work piece can be arranged in an overlapping forming plane. The first contour and the second contour can be pressed against each other through a forming zone. The device has at least one source of radiation to facilitate electromagnetic radiation that serves to heat the work pieces between the tools. The device according to the invention is characterized in that laterally to the tools there is arranged, respectively, at least in each case a radiation source such that its electromagnetic radiation is directed, respectively, on the workpiece directed towards the source of radiation and the forming area. Each of the radiation sources is formed by at least one emitter of direct irradiation diodes. In this regard, each source of

Radiation is formed by emitters of directly radiating diodes arranged annularly around the tool.

The one or more diode emitters may be arranged in a module. In addition, an optics may be present whereby the electromagnetic radiation of each of the radiation sources is influenced, for example, is grouped and directed. The radiation sources are advantageously linked to a control by which parameters of the electromagnetic radiation emitted by the radiation sources can be controlled, for example, duration of emission and intensity.

Preferably, the at least one diode emitter of a radiation source is arranged such that at

Through the electromagnetic radiation emitted by the radiation source and directed to the forming zone, a focal spot is formed in the forming zone.

The radiation source is preferably arranged in such a way that the electromagnetic radiation is directed from a direction on the side of the tool to the forming plane and the forming area.

In this regard, it is particularly preferred that the radiation source be arranged near and next to the side directed towards the forming area of one of the tools.

Preferably, they are directed from an area near and next to the side of each tool to the forming area 45 which is directed respectively to the forming area.

For joining, a first workpiece and a second workpiece are placed between the first tool that has a first contour and the second tool that has a second contour in the overlapping forming plane, such that they are placed in contact through a forming zone. Now, on each side directed towards the outside of the work pieces, electromagnetic radiation is directed through the forming zone and the forming zone on the side of each work piece is simultaneously exposed to electromagnetic radiation.

After heating, the first contour and the second contour are pressed together, in such a way

55 that the work pieces are formed through the heated forming zone corresponding to the first contour and the second contour.

Electromagnetic radiation can be all radiation that is suitable for heating the materials to be formed. Preferably, electromagnetic radiation is a laser radiation.

The use of diodes or emitters of direct radiation diodes has the advantage that the emitted radiation can be directed without major losses by absorption and dispersion to the forming area and an energy-efficient heating of the work pieces can be performed. By direction of the electromagnetic radiation from laterally in each case of one of the tools, tools can be used without steps or similar devices permeable to radiation. In addition, a focal spot in the forming plane can be easily controlled and corrected in relation to its size, shape, location and intensity distribution (in the

space time). The parameters mentioned above must be adapted, for example, to the material, the thickness of the material, etc. of the work pieces to be shaped or to be corrected during a series of forming procedures.

5 It is possible to use pulse electromagnetic radiation, there being a simultaneous exposure also when the electromagnetic radiation to which one of the work pieces is exposed and the electromagnetic radiation to which the other work piece is exposed have phase shifting from each other. Thanks to the exposure made from both sides, the work pieces are heated at least through their forming area. The work pieces are then formed by compression of the tools.

The invention is explained in more detail in the following by means of the figures and the examples of embodiment. In this regard they show

Figure 1, a first embodiment of the device as a basic scheme;

Figure 2, a second embodiment of the device with a diode emitter module;

Figure 3, a third embodiment of the device with two radiation sources per tool;

Figure 4, an embodiment of the device according to the invention with a source of annular radiation in a tool.

As essential parts of a device according to the invention are shown in Figure 1 a first tool 5 with a first contour 5.1 and a second tool 6 with a second contour 6.1, as well as two

25 radiation sources 7, a radiation source 7 being arranged next to the first tool 5 and the other radiation source 7, next to the second tool 6.

The first tool 5 and the second tool 6 can be moved in an approach direction 11 or against the approach direction 11 and can be brought closer together. The first contour 5.1 and the second contour 6.1 are present, respectively, on a front surface that has a perpendicular path with respect to the approach direction 11 of the first tool 5 or the second tool 6 as elevations and cavities complementary to each other. The first contour 5.1 and the second contour 6.1 may have been brought into direct contact with each other by approaching the first tool 5 and the second tool 6 in a forming plane 3.

35 In the forming plane 3, a first workpiece 1 and a second workpiece 2 are placed one above the other and can be moved along a transport direction 10. No fasteners of the workpieces 1 are shown. , 2 and means for transporting work pieces 1, 2 in the transport direction 10.

If the first tool 5 and the second tool 6 are close to each other, their first contour 5.1 and second contour 6.1 are in the forming plane 3. A forming area 4 of the first tool 5 and the second tool 6 is gives by extending the first contour 5.1 and the second contour 6.1 in the forming plane 3.

The first contour 5.1 is configured as an elevation and the second contour 6.1 as a cavity, the dimensions of the elevation allowing a pressurized introduction of the existing material in the forming area 4 of a first workpiece 1 and a second piece of Work 2 in the cavity of the second contour 6.1 (not shown). A matrix is formed through the first tool 5 and the second tool 6 as well as their contours 5.1 and 6.1.

Laterally next to the first tool 5 and the second tool 6 there is respectively a radiation source 7 to facilitate electromagnetic radiation. The radiation source 7 is formed by a direct irradiation diode emitter. The electromagnetic radiation is directed along respectively a ray path (shown schematically) in, in each case, an irradiation direction 8 on respectively the part

Working 55 or 1 that is directed towards the respective radiation source 7. In this respect, the electromagnetic radiation is directed, respectively, to the forming plane 3 and the forming area 4, such that on the surfaces of the Workpieces 1 or 2 that are directed towards the respective radiation sources 7 are reproduced electromagnetic radiation in, in each case, a focal spot 9 (see Figure 2). The size and shape as well as the distribution of energy through the focal spot 9 are chosen in such a way that the first workpiece 1 and the second workpiece 2 are heated through the forming area 4.

By means of a control 13 which is connected with signal conduction with the radiation sources 7, the radiation sources 7 can be controlled in relation to the parameters of the emitted electromagnetic radiation as well as the

65 duration of emission and intensity.

In other embodiments, the first contour 5.1 and the second contour 6.1 may be otherwise formed, for example, rounded, widening at the base (for example for cold deformation joining) or be conical. There may also be more than two pieces of work in the forming plane 3.

5 In a second embodiment of the device according to Figure 2, the radiation source 7 arranged next to the first tool 5 is configured as a module composed of several emitters of directly radiating diodes. In front of the emitters of diodes there is an optics 12 whereby the electromagnetic radiation emitted by the emitters of diodes is grouped, directed along the direction of radiation 8 and reproduced in a focal spot 9 on the surface of the first Workpiece 1. For the radiation source 7 arranged next to the second tool 6, the foregoing is fulfilled correspondingly (not shown). The module is connected to a control 13.

In a third embodiment of the device, according to Figure 3 laterally to the tools 5, 6, two radiation sources 7 are respectively arranged, whose emitted electromagnetic radiation is reproduced in

15 a focal spot 9 common on the surface of the first workpiece 1 or the second workpiece 2. The radiation sources 7 in other embodiments can be configured, respectively, also as a module composed of several diode emitters of direct irradiation, to which an optic 12 is placed. The radiation sources 7 can be controlled individually through the control 13.

An embodiment of the device according to the invention is shown in Figure 4, in which the radiation source 7 is formed by emitters of direct irradiation diodes arranged annularly around a tool 5, 6 (shown very schematically). A view in the direction of approach 11 to the first contour 5.1 of the first tool 5 and on the radiation source 7 is shown by way of example only.

In other embodiments of the device according to the invention, the radiation sources 7 on both sides of the forming plane 3 may be of the same type, for example, as shown in Figure 1 or Figure 2, or they may be of different type. Thus, the radiation sources 7 shown in Figures 1 and 2 can be combined in one device. There may also be other amounts of radiation sources 7 on one side of the forming plane 3 which, in turn, can be of the same or different type.

Next, the operation of the device according to Figure 1 will be explained. A first work piece and a second work piece 2 are superimposed on the forming plane 3 and are kept there. The first workpiece 1 is directed upwards, the second workpiece 2 is directed downwards. The two pieces of work 1 and 2 will be prepared in such a way that an area through which they are to be

35 forming the two work pieces 1 and 2 coincides with the forming area 4. The radiation sources 7 are connected and the electromagnetic radiation is directed, respectively, to the forming plane 3 and the forming area 4, whereby they heat the first workpiece 1 and the second workpiece 2 through the forming area 4. If the two workpieces 1 and 2 have been sufficiently heated, the radiation sources 7 and the upper tool 5 are disconnected and the lower tool 6 approach each other along the approach direction 11 until the material of the two work pieces 1 and 2 has been pressurized through the forming area 4 to the first contour 5.1 in the second contour 6.1. In this respect, the first workpiece 1 and the second workpiece 2 are deformed plastically through the forming area 4. After forming, the upper tool 5 and the lower tool 6 are separated again along of the approach direction 11 and the work pieces 1 and 2 move along a

45 transport direction 10 in the forming plane 3 until the next area through which the first workpiece 1 and the second workpiece 2 have to be formed are in the forming zone 4.

The device according to the invention can be applied in the technological fields of the joining technique, for example, in the construction of bodies.

Reference List

1 first piece of work

55 2 second work piece 3 forming plane 4 forming area 5 first tool

5.1

first contour 6 second tool

6.1

second contour 7 radiation source 8 radiation direction 9 focal spot

65 10 transport address 11 approach address

12 optics 13 control

Claims (2)

1. Device for joining a first workpiece (1) and a second workpiece (2) with a first tool (5) presenting a first contour (5.1) and with a second tool (6) presenting a second 5 contour (6.1), between which the first workpiece (1) and the second workpiece (2) can be superimposed on a forming plane (3), the first contour being able to be pressed against each other ( 5.1) and the second contour (6.1) through a forming area (4) and at least one radiation source (7) to provide electromagnetic radiation that serves to heat the work pieces (1, 2) between the tools (5, 6), characterized in that 10 -laterally to the tools (5, 6), respectively, at least, in each case, a radiation source (7) is arranged, so that its electromagnetic radiation is directed respectively on the workpiece (1, 2) directed to the radiation source (7) and the forming zone (4) and -each one of the radiation sources (7) is formed by at least one emitter of direct irradiation diodes, 15 each radiation source (7) being formed by emitters of direct irradiation diodes arranged annularly around the tool (5, 6). 2. Device according to claim 1, characterized in that the at least one diode emitter of a radiation source (7) is arranged in such a way that by means of the electromagnetic radiation emitted by the 20 radiation source (7) and directed towards the forming area (4) is formed, on the surface located in the forming area (4) of the workpiece (1, 2) directed towards the radiation source (7 ), a focal spot (9) whose size, shape, location and intensity distribution in space / time can be controlled.