WO2015032719A1

WO2015032719A1 - Beam-assisted joining machine, in particular laser transmission welding device having a clamping means formed by a flexible clamping hose

Info

Publication number: WO2015032719A1
Application number: PCT/EP2014/068513
Authority: WO
Inventors: Michael Bauer; Sebastian Loy; Stefan Schlauderer
Original assignee: Lpkf Laser & Electronics Ag
Priority date: 2013-09-04
Filing date: 2014-09-01
Publication date: 2015-03-12
Also published as: DE102013217647A1

Abstract

The invention relates to a beam-assisted joining machine, in particular a laser transmission welding device, comprising a beam head (1) for providing a joining beam (L) that produces a weld (5) between two components (3, 4), a holder (6) for supporting the first component (3), a clamping device (2) for clamping the components (3, 4), in particular for clamping components (3, 4) having a weld (5) extending in three dimensions, which clamping device (2) has a clamping frame (11) that cooperates with the holder (6) and has a clamping means for producing a clamping force (F) between the two components (3, 4) at least in the region of the particular joining zone to which the joining beam (L) is applied, and a flexible clamping hose (9), which acts on the two components (3, 4) as a clamping means and is arranged the cross-section of the clamping hose between the clamping frame (11) and the components (3, 4) and the clamping force (F) of which is produced by introducing a pressure fluid into the hose lumen (SL).

Description

BEAM-SUPPORTED SLOT MACHINE, ESPECIALLY LASER RADIATION WELDING DEVICE WITH A SPANNER SHAPED BY A FLEXIBLE SPANNING TUBE

The content of German Patent Application 10 2013 217 647.3 is incorporated herein by reference.

The invention relates to a beam-assisted joining machine and in particular a laser transmission welding device with the in the preamble of

Claim 1 features specified.

10

Such joining machines can also be realized by laser butt welding, laser soldering or the like in addition to the aforementioned laser beam welding.

As is known, for example, from DE 10 2007 042 739 A1

beam-assisted joining machines, a jet head for providing a connecting seam between the two components generating joining beam, a receptacle for mounting a first component and a clamping device for clamping the two components. In the clamping device according to the above-mentioned document 0 an inner clamping punch is provided which the

Clamping force in the area bordered by the weld initiates. Another embodiment - the above-mentioned DCD technique - this tensioning device is based on thin webs that mechanically connect an outer clamping frame with the inner clamping punch. In this case, there is a sufficient gap between the outer and inner clamping technology

Form weld. A holder of the inner clamping punch on a transparent glass plate is known. This type of tensioning device is problematic for a three-dimensionally extending joint seam, since then the frame-shaped inner clamping jaws or the individual clamping jaws which grip from the outside inwards become very complicated in terms of their mounting and construction. A disadvantage of the use of the above-described stamp clamping technique in combination with the contour welding method is also the relatively poor gap bridging. This is due to the fact that the clamping die is in full-surface contact with the component, but the material is plasticized only at certain points.

DE 101 33 956 AI discloses a clamping device for laser soldering or laser welding, in which there is a so-called geometry clamping means is provided which has a shape adapted to the contour of the respective component. By a negative pressure, which is generated in particular by a plurality of individual suction cups, the component applies against a surface of the mold non-positively and flat. The disclosed clamping device is also very complex and problematic due to the suction cups used in the tension of components with three-dimensional running joint seam.

DE 100 60 394 AI discloses a device for fixing by means of a laser to be welded components. The jaws are made of a material transmissive to the laser beam. As far as the current state of the clamping technology is concerned, it should be noted that mainly the above-mentioned inner clamping punches are used, which are designed as three-dimensional negative forms of the upper component. These have several disadvantages, such as the high cost associated with their manufacture. Furthermore, sensitive surfaces of the components to be joined can be a problem. Then special precautions must be taken in the known clamping techniques to prevent scratching of the workpieces.

Another problem area is the necessary constant distribution of the clamping force along the weld during laser welding of plastics. If the manufacturing tolerances of the component holder on the one hand and the machined, for example, injection-molded components on the other hand taken into account, it is difficult to ensure a constant distribution of clamping force. In addition, the "rigid" clamping technique described in the prior art does not permit any melting path when using a contour welding process.The reason for this is that in this variant of the method the laser beam is guided relatively slowly along the welding contour, whereby only a very small area of the seam is constantly used melted, the surrounding, unplasticized areas prevent setting of the transparent, upper member relative to the lower.

To the current state of the clamping technology are finally still local clamping techniques to mention, which selectively compress the components to be welded at the point of the current welding. This can be done, for example, by means of a tensioning roller or a glass ball used at the same time as an optical element.

These selective clamping techniques also have the disadvantage that they can lead to damage to the component Oberiläche. Furthermore, the fact that these clamping techniques are fixed on the welding head are build and down to the component protrude, to the fact that a variety of component geometries are not editable, as it would lead to a collision between clamping components and component. Based on the described problems of the prior art, the present invention seeks to improve a beam-assisted joining machine with respect to their clamping device for clamping the components so that a high clamping force applied even with a joint seam with a complex course in an effective and flexible manner on the components can be.

This object is achieved conceptually by the features stated in the characterizing part of claim 1. Accordingly, the tensioning means is formed by a flexible tensioning hose which acts on the two components and is arranged with its cross section between the tensioning frame and the components. The clamping force on the components is generated by applying a pressure fluid to the tube volume. The function of the component voltage is thus taken over by a flexible component in the form of the clamping tube, which ensures a very uniform distribution of the clamping force across the components. This hose technology also protects the components to a particular degree, because the clamping force is applied over the entire clamping zone by means of a flexible element. Due to the flexibility of this clamping means and no exactly adapted to the shape of the components to be clamped clamping means must be provided. It is sufficient if the tension hose to a roughly the shape of the components to be clamped following tenter is attached. Incidentally, the latter can also be designed as a transparent lid for the joining beam.

The flexibility of the tension hose also brings with it the advantage that setting paths of the components can proceed unhindered during the joining. Thus, also component tolerances can be better compensated.

Preferred developments of the subject invention are specified in the dependent claims. Thus, a particularly effective tension of the components is ensured when the tension hose runs along the clamping frame and the two components in its peripheral edge region - ie applied along the joining zone - with the clamping force. The application of the clamping force on the components and the effective zone of the clamping force are thus optimally close to each other.

In order to make it possible to join the components even in the region of the components covered by the tensioning tube, the tensioning tube consists of a material transmissive to the joining beam. Compressed air as compressed air is an advantage since it is also highly transmissive to the joining jet and is usually available as a working medium at production sites.

The tension hose is preferably made of an elastic material, so that uniform tensioning properties are ensured even over a longer service life of the joining machine. A high elasticity with simultaneous resistance to higher process temperatures is beneficial for the tubing. These properties are fulfilled, for example, by PTFE or ETFE hoses. Further preferred embodiments relate to the implementation of the tension hose conception in an internal, external or combined clamping technology. Thus, the tensioning hose can be positioned on the outside at a clamping frame arranged within the joining seam contour of the components, a position-related reverse positioning is likewise possible. As a combination of both variants combined inner and outer frames can be used, which are interconnected, for example, via the above-mentioned to the prior art DCD clamping technology.

Further alternative embodiments of the subject invention relate to the formation of the tensioning tube itself as either closed ring tube or as end open hose. Further features, details and advantages of the invention will become apparent from the following description of an embodiment with reference to the accompanying drawings. 1 shows a section through a tensioning device with a schematically illustrated jet head,

Fig. 2 is a perspective view of the clamping device in the closed state, and Fig. 3 is a schematic sectional view of the clamping device according to the

Section line III-III of FIG. 1.

As is clear from FIG. 1, the laser transmission beam shown as an example for a beam-supported joining machine has Welding device on a jet head 1, to which a laser beam, not shown, a laser beam L suitable for conventional transmission welding is brought to. The jet head 1 is - as also not shown in detail - performed by a corresponding multi-axis handling device according to the three-dimensional contour of the weld 5 to be produced (see Fig. 3) between the two held in the clamping device 2 components 3, 4 of a product designed as a hollow body , This product may be, for example, a tail lamp unit of a motor vehicle, wherein the first component 3 is formed by the rear housing of the lamp. This housing consists of a laser-absorbing material, whereas the laser-transmissive and translucent cover of the luminaire forms the second component 4. The two components 3, 4 are acted upon for welding in the clamping device 2 with a corresponding clamping force F in order to produce a perfect, continuous joint seam in the form of a weld 5 (see FIG. 3) between the two components. The lower, housing-like component 3 is thereby inserted into a receptacle 6 of the clamping device 2 in a defined position. For this purpose, the receptacle 6 a the component 3 in the form adapted receiving opening 7, the bottom 8 serves as a support surface for the component 3. As the actual tensioning device, a function along the contour of the

Weld 5 circumferential clamping hose 9 made of a very elastic, for the laser beam L highly permeable PTFE material which is attached to a frame cover 12. For this purpose, the tensioning tube 9 in a trained as a groove mounting surface 10 to the corresponding, the Frame cover 12 forming frame struts 13 secured by means of a suitable adhesive.

As becomes clear in particular from FIG. 3, the tensioning hose extends with its cross section between the clamping frame designated as a whole by 1 1 and the components 3, 4 formed by the frame cover 12.

The clamping hose 9 designed as a circumferential annular hose is-as indicated in FIG. 3-provided with a connection 15 for a compressed-air line 16, which-as is indicated schematically in FIG. 1-is connected to a suitable compressed-air source 17. By applying the hose lumen SL with compressed air, the clamping force F is now applied to the components 3, 4.

The frame cover 12 itself is hinged on a narrow side via integrally formed bearing flanges 18 on a bearing block 19 on the receptacle 6 by means of the bearing pin 20 pivotally. The bearing pin 20 is secured on both sides with locking rings, not shown in its mounting position shown in Fig. 2. The bearing block 19 is bolted four times with the receptacle 6.

For fixing the frame cover 12 in the closed position shown in FIG. 2, a quick-release closure 21 is provided with an actuating handle 22, a retaining clip 23 pivotally mounted thereto and a hook 24 on the frame cover 12. The quick-release shutter 21 is based in its function on a conventional over-center kinematic. After insertion of the components 3, 4 and the closing of the frame cover described above, the components 3, 4 are braced by Drackluft- beauschlagung the hose lumen SL. This can be the

Start welding process, wherein the laser beam L penetrates both the tension hose 9 and the transparent upper component 4. It is absorbed in the usual way by the lower component 3, whereby a melting takes place with a corresponding heat transfer to the upper component 4 with a corresponding cohesive connection to form the weld 5. After completion of the welding process, the tension hose is vented and thus removed the clamping force F, the frame cover 12 can be opened and the thus finished welded product can be removed from the jig 2.

Claims

claims

1. Beam-supported joining machine, in particular laser Durchstrahl- welding device comprising

a jet head (1) for providing a joining jet (L) which generates a joining seam (5) between two components (3, 4),

- A receptacle (6) for mounting the first component (3), and

- A clamping device (2) for clamping the components (3, 4), in particular for clamping of components (3, 4) with a three-dimensionally extending joint seam (5), which clamping device (2) cooperating with the receptacle (6) clamping frame ( 1 1) and a clamping means for generating a clamping force (F) between the two components (3, 4) at least in the region of each of the joining beam (L) acted upon joining zone,

characterized in that

- The clamping means by one of the two components (3, 4) acted upon, flexible clamping hose (9) is formed, which arranged with its cross section between the clamping frame (1 1) and the components (3, 4) and its clamping force (F) Actuation of the tube lumen (SL) is generated with a pressurized fluid.

2. Joining machine according to claim 1, characterized in that the

Clamping hose (9) along the clamping frame (1 1) extends and the two components (3, 4) acted on in its peripheral edge region with the clamping force.

3. Joining machine according to claim 2, characterized in that the

Tensioning tube (9) made of a material that is transmissive to the joining beam (L) material exists.

4. Joining machine according to one of the preceding claims, characterized in that the pressurized fluid is compressed air.

5. Joining machine according to one of the preceding claims, characterized in that the clamping hose (9) consists of an elastic material.

6. Joining machine according to one of the preceding claims, characterized in that the clamping hose (9) is positioned on the outside of a within the contour of the joining seam (5) of the components (3, 4) arranged clamping frame.

7. Joining machine according to one of the preceding claims, characterized in that the clamping hose (9) is positioned on the inside of a outside of the contour of the joining seam (5) of the components (3, 4) arranged clamping frame (1 1).

8. Joining machine according to one of the preceding claims, characterized in that the clamping hose (9) in the clamping frame (1 1) is glued.

9. Joining machine according to one of the preceding claims, character- ized in that the clamping tube (9) is designed as a closed annular tube with a connection (15) for filling with the pressurized fluid.

10. Joining machine according to one of claims 1 to 8, characterized in that the tensioning hose is designed as an open end hose, wherein the pressurized fluid can be fed via at least one of the open ends.