WO2010069599A1

WO2010069599A1 - Device and method for laser beam joining

Info

Publication number: WO2010069599A1
Application number: PCT/EP2009/009156
Authority: WO
Inventors: Andrei Boglea; Michael Aleff; Arnold Gilner
Original assignee: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
Priority date: 2008-12-19
Filing date: 2009-12-18
Publication date: 2010-06-24
Also published as: DE102008063975A1

Abstract

The invention relates to a clamping device for bracing two joining parts (1,2), which comprises a reservoir (10) that is or can be filled with a gaseous or liquid medium and bordered on at least a portion of the circumference thereof by a flexible element (3), wherein the joining parts (1,2) to be braced can be brought in contact with the flexible element (3) such that a force can be applied to at least one of the joining parts (1,2) to be braced by means of a pressure that can be generated in the reservoir (10) by way of the flexible element (3). The invention also relates to a method for laser beam joining two joining parts (1,2) which is performed using said clamping device.

Description

FPL case number 08F49691 ILT 1 16 12 2009

Patent Application:

Apparatus and method for laser beam joining

Applicant: Fraunhofer-Gesellschaft for the promotion of applied research e.V.

Technical application

The invention also relates to a corresponding method for laser beam jointing of two joint partners, in which the joint partners braced with each other before and / or during the application of laser radiation The preferred field of application is the Laserdurchstrahlfugen of components, such as the welding of plastic components, in particular of thermoplastic materials, and the laser beam bonding of silicon and glass Another field of application is, for example, the glass soldering

State of the art

Since the beginning of the 90s, the laser transmission joints, in particular the laser transmission joints of plastics, has become an established method. Growing components by creating a laser beam overlapping connection between a component that is transparent to the laser beam and a component that absorbs the laser beam is called Laser transmission welding The most well-known method of application of the method is plastic welding, but also for other materials that are transparent or at least partially transparent for laser radiation, such as Sihzium glass composites and glass solders, the method of laser transmission is used in all these methods FPL case number 08F49691 ILT 2 16 12 2009

Fugal partner arranged so that the laser beam first meets the transparent Fugepartner and this penetrates After passing through the first Fugepartner the laser beam strikes the second Fugepartner, which is itself absorbing for the laser radiation or grouted by a laser radiation absorbing cover layer by the irradiation of the absorbent Fugepartners creates heat, which leads with sufficient thermal contact, depending on the method to a melting of the joint partners or to a thermally induced chemical reaction

In the case of plastic welding, not only the absorbent, but also the transparent joint partner is plasticized so that the molecular chains can diffuse into one another. In plastic welding, residual gaps of up to 150 μm can be bridged due to the thermal expansion of the absorbing joint partner the manufacturing process tolerances in terms of accuracy of fit on These are the greater, the more complex and larger the components are often the resulting residual gaps between the joint partners, however, are larger than 150 microns, so that the heat conduction between the joint partners is prevented This leads in many cases to one Insufficient plasticization of the transparent joint partner and thus insufficient strength of the welded joint

The laser beam bonding of silicon and glass is based on the use of adhesion forces and the formation of chemical compounds at the Fugestelle Since this process thermal expansion can not be used due to the small expansion coefficients, the components are here even with zero gap to fix each other

In the above-mentioned and further examples of application, it is therefore necessary for the joint partners to be braced in advance in order to exclude or at least minimize residual gaps between the joint partners

Special requirements are placed on the clamping technology. Thus, the laser beam should not be obstructed or shaded by the clamping device. For complex components with three-dimensional contours and sudden contour changes, the clamping of the joint partners can be achieved by conventional methods FPL Case Number 08F49691-ILT 3 16 12 2009

Therefore, do not use inserts or only with very complex clamping devices.

For transferring the joining pressure necessary for bracing, e.g. from E. Haberstroh et al.: "Laser transmission welding of plastics", KGK - Rubber Gummi Kunststoffe 11/2006, S. 590-595 the use of a glass plate known. This is pressed against the components to be clamped. The glass plate is transparent to the laser beam and is therefore suitable as the laser source facing jaw To clamp three-dimensional or inaccurately made two-dimensional surfaces, a glass plate is unsuitable, since glass plates usually have flat surfaces. The pressure can therefore not be applied homogeneously over the seam geometry in the case of complex components. Although it is possible to provide the glass plate additionally with a transparent and adapted to the weld stamp. Due to the component-specific stamp to be produced, however, the replaceability of the clamping device is severely limited. Alternatively, it is also possible to use a clamping goggle adapted to the component contour, which applies the pressing pressure from the outside. The area to be welded remains free. However, the parts to be joined must be designed with a peripheral edge as support surface for the tensioning goggles. In addition, the non-symmetrical pressurization can lead to mechanical distortion or to additional gap formation.

In addition, EP 1405713 A1 discloses the bracing of two plastic workpieces by mechanical pressing by means of a transparent glass ball. This can be moved rolling over the transparent joining partner and also serves as a focusing lens for the laser radiation. Although three-dimensional joining partners can be clamped together with this arrangement, the concave seam courses must have larger radii than those of the glass ball; in particular, sudden contour changes (eg 90 ° angles) can not be clamped in this way. FPL case number O8F49691-ILT 4 16 12 2009

The invention is therefore based on the object to provide a device and a method for clamping two joining partners, which mechanical stresses and an additional gap formation are avoided, which / moreover quickly and flexibly for differently shaped, especially for very complex three-dimensional components used , and which / which is particularly suitable for the laser transmission joining.

Presentation of the invention

The solution of this technical problem is achieved by a method and a device according to the independent claims. Advantageous embodiments and further developments are indicated by the dependent claims or can be taken from the following description and the exemplary embodiments.

According to the invention, it has been recognized that the technical problem is solved by a clamping device for clamping two joining partners, which comprises a reservoir which is filled or filled with a gaseous or liquid medium and which is delimited at least partly by a flexible element. The joint partners to be clamped can be brought into contact with the flexible element in such a way that a force can be exerted on at least one of the joint partners to be clamped by a pressure that can be generated in the reservoir via the flexible element.

The invention thus avoids uneven pressurization. The pressure which can be generated in the reservoir according to the invention results in a flexible element against the joining partners, and thus indirectly in a force pressing against one another against the joining partners. Since the pressure in the reservoir is homogeneous or nearly homogeneous, the force acting on the flexible element or indirectly on the joining partners is distributed spatially very homogeneously. Mechanical tensions or additional gap formations between the Fügepartπern be avoided. FPL Case Number 08F49691 ILT 5 16 12 2009

The element that is brought into contact with the joint partners to be clamped, is flexible, ie not stiff but yielding, so that it is deformable in the force generated by the pressure generated in the reservoir It may for example be elastic, in particular so elastic that it at The force effect by the pressure generated in the reservoir can change its shape and preferably returns to its original shape after its removal or at least largely returns to its original form. However, it can also be elastic only to a limited extent, in particular it can be viscoelastic or plastically deformable In any case, it is preferably deformable again, at least after deformation, so that it can be used many times in succession for bracing, whereby the duration of the process is shortened and the service life of the device is increased

The flexibility, ie in particular the flexibility, flexibility and deformability, of the flexible element makes it possible and is preferably so pronounced that its surface topography can conform to the contour of a joint partner to be clamped. In particular, the flexible element can be stretched, stretched or curved The flexible element is able to fit tightly to the contour of the joint partners when the pressure is suitably selected. The choice of the flexible element, and in particular its compliance or deformability, and the height of the pressure generated in the reservoir, are expressed differently As a result of this pressure, the flexible element fits tightly against the contour of the joint partners. As a result, the force effect is distributed spatially homogeneously over the entire surface of the joint partners facing the elastic element

Therefore, the joint partners can in particular be designed three-dimensionally - ie the method is not limited to pure flat structures - without a specially adapted to these Fugepartner pressing must be made The clamping device is thus very versatile, without long Umrustzeiten occur

In particular, the device according to the invention has particular advantages in laser beam jointing. In this case, the device can be configured in a simple way, in particular, such that when the joint partner is braced FPL Case Number 08F49691 ILT 6 16 12 2009

Shading of the laser beam, with which the joint partners grooved, can be avoided altogether Preferably, the clamping device for this purpose has an optical access through which a loading of the joint partners with radiation of the laser beam source is made possible. In particular, the flexible element is suitably designed for this purpose is the flexible element for radiation in the range of 400 to 3000 nm, preferably in the range of 700 to 2200 nm, and in particular for the radiation of the laser beam source transparent or at least substantially transparent Thus, a laser exposure of the joint partner through the flexible element can be carried out

A suitable flexible element may, for example, comprise a polymer component or consist of a polymer. The flexible element preferably has a silicone and / or Teflon component or consists of silicone and / or Teflon silicone has a high transmission in said radiation region and a high degree of flexibility, Teflon has a high temperature resistance

The medium used to charge the reservoir is or is a gaseous or liquid medium. For use in laser beam grouting, the medium is preferably also for radiation in the range from 400 to 3000 nm, preferably in the range from 700 to 2200 nm , and in particular for the radiation of the laser beam source used transparent or at least substantially transparent As a medium well suited, especially for use in laser beam joints, for example, air, which is characterized in particular by the fact that it is highly transparent and very readily available and leaves no pollution, so that the equipment and financial expenditure comparatively low remains The same advantages have water, which in addition a high thermal conductivity is given

The reservoir is a space which is at least tight during the tensioning process for the contained gaseous or liquid medium. The tensioning device may comprise one or more closable inlet means for admitting the medium into the reservoir, with which the pressure of the medium in the reservoir is preferably adjustable will at least teilumfanghch FPL case number 08F49691-ILT 7 16 12 2009

bounded by the flexible element. The volume of the reservoir is preferably variable due to the flexibility of the flexible element.

It is also possible that the reservoir is completely bounded by the flexible element. In this case, the reservoir bounded by the flexible element constitutes a "fluid pad."

Preferably, the clamping device has one or more limiting means, which alone or together with the joining partners to be clamped a chamber or together with the joining partners to be clamped and with a support element on which the Fύgepartner placed or can be fixed to the joining partners, can form a chamber which is impermeable to the flexible element located therein.

The one or more limiting means can thus, according to a first alternative, already alone form a chamber; in order to clamp two joining partners, they must first be opened in this case and the joining partners with the relative positioning with which they are to be connected are to be placed therein; then the chamber is to be resealed so that it is impermeable to the flexible element located therein. Such a chamber could e.g. by a base plate as a first limiting means on which the joining partners can be placed and one or more further limiting means in the manner of a bell, which is placed on the base plate, the joining partners in the chamber, is placed realized.

Depending on the application, it may also be advantageous if the one or more limiting means not yet alone, but together with the joining partners to be clamped, or together with the joining partners to be clamped and with a support element, form a chamber. In this case, the chamber is thus not part of the tensioning device, but is formed during the tensioning process. For this purpose, the one or more limiting means is brought into contact with at least one of the joint partners to be clamped, for example, on it, that forms a cavity between them, so they together form a chamber. FPL case number 08F49691-ILT 8 16 12 2009

Alternatively, the one or more limiting means is so brought into contact with the support element on which the Fugepartner or to which they are fixed, z B on it, that they together form the chamber For the support element many embodiments are conceivable Provided for the support element alone, that the Fugepartner can be placed on it or can be fixed thereto and that it is suitable to oppose during the tensioning operation on at least one of the force to be clamped Fugepartner a counterforce, preferably the support element is rigid and in the direction of at least one The support element can, but need not be part of the clamping device It can thus be a used in each clamping component, but it is also possible that a support element is provided individually for each clamping operation As a support element esp especially a table or the support surface of a conveyor belt in question

Regardless of whether the chamber is already part of the clamping device or is formed only during the clamping operation together with the joint partners to be clamped or together with the joint partners to be clamped and with the support element, it is or is in any case designed so that they for the then flexible element is impenetrable

By virtue of the fact that it is impermeable to the flexible element located therein, the chamber constitutes the outer boundary for the reservoir. In this way, the force produced in the reservoir can be metered and homogeneously forwarded to the joint partners in a force acting homogeneously on the flexible element

The flexible element in the chamber preferably separates the reservoir from a region provided for receiving the joint partners. The chamber thus has two regions, namely a region containing the reservoir and an area provided for receiving the joint partners Element separated, in particular, this is a preferably airtight and tight in relation to the medium given separation This causes a simple and fast FPL case number O8F49691 ILT 9 16 122009

Handling of the device and thus its economic usability in mass production

The or the limiting means or is designed so that they and in particular the chamber can withstand the pressure generated in the reservoir during the tensioning operation Preferably, to ensure the tightness of the chamber and / or that the chamber for the flexible element located therein is impenetrable For this purpose, a bell, which is placed over a base plate and the lying thereon Fugepartner be doing with a fixing force to the base plate to be printed, which is sufficient that the bell is due to the production of the pressure in the reservoir does not repel the base plate and thus withstand this pressure

The generation of the pressure in the reservoir can be particularly simple if the clamping device comprises a Druckeinstelleinπchtung for changing the pressure of the medium in the reservoir For this purpose, the Druckeinstelleinπchtung preferably at least one means, with which increases the amount of the medium in the reservoir and / or at least one means with which the volume of the reservoir can be reduced

For example, as an agent for increasing the amount of the medium in the reservoir, an inlet device for introducing the medium into the reservoir may be present. This can easily increase the pressure of the medium in the reservoir. The pressure that can be generated in the reservoir, through which a force is applied via the flexible element can be exercised on at least one of the joint partners to be clamped or the force acting on at least one of the joint partner to be clamped by the flexible element force can thus be adjusted accurately and reproducibly with little effort

Alternatively (or additionally), a means may be provided with which the volume of the chamber, in particular of the reservoir, can be reduced. For example, the clamping device may comprise an adjusting device with which a limiting means or the support element relative to a (other) limiting means and / or or the flexible element can be moved so that FPL Case Number 08F49691 ILT 10 16 12 2009

For example, for a limiting element may be designed as a hollow body, in which a further limiting element or the support element is guided in the manner of a Zyhnderkolbens to mechanically generate the required pressure in the reservoir in this way

The pressure which can be generated in the reservoir is typically between 1 bar and 200 bar, preferably between 2 bar and 7 bar. In cooperation with the elastic element, this enables an optimal clamping effect

In a particularly preferred embodiment of the invention, the tensioning device has a heating device with which the temperature of the medium can be increased. The temperature increase by means of the heating device can take place either within the reservoir or even before the medium enters the reservoir

Due to the increased temperature of the medium, the jointing process can be further supported. The warming of the flexible element caused by the warm medium further increases its flexibility. This increases the adaptability of the flexible element to the contour of the joint partners, whereby the homogeneity of the force on the joint partners increased again and the risk of caused by the clamping process mechanical tension or additional gap formation between the joint partners is further reduced

Also, the Fugepartner, in particular the upper Fugepartner, are heated indirectly, namely by the warm medium (and by the thus heated flexible element) This also facilitates the contact pressure and the melting of the Fugepartner By the effective heating of the upper Fugepartners, with the same energy of Preferably, the temperature of the medium during the clamping process is selected so that the rigidity is markedly reduced by the resulting heating of the upper joint partner. At the same time, the temperature of the medium during the clamping process is, of course, below the melting temperature of the flexible element The selection of the flexible element and the preheating of the medium is so far corresponding to each other and on the joint partner to be clamped FPL case number 08F49691-ILT 11 16 12 2009

or at least matched the upper joint partner. Typically, the temperature of the preheated medium is between 40 and 500 ^° C.

By reducing the rigidity of the upper joining partner stress cracks due to residual stresses can be avoided. Due to the greater flexibility of the heated joint partners or larger gap masses can be bridged between the joining partners beyond.

As already stated, the joining partners to be clamped according to the invention are brought into contact with the flexible element in such a way that a force that can be generated in the reservoir can be exerted on at least one of the joining partners to be clamped via the flexible element. Typically, the two joining partners are placed in the desired positioning to each other on a support element or fixed thereto. As a rule, the joining partners are thus brought into contact with the flexible element directly and directly during the clamping process, namely only their surface areas, which constitute an immediate interface of the chamber formed during the clamping process; In many applications, there is a direct direct contact especially or essentially only with one of the joining partners, in extreme cases, the direct contact can be made exclusively with one of the joining partners.

It is of course also possible that the joint partners are only partially braced. In particular, it is possible with very extensive joining partners that several areas are successively processed by the clamping device. On the other hand, it is advantageous if the clamping device is designed such that even very large joining partners can be clamped during the duration of only one clamping operation. For this purpose, the Spannvorrichung according to a preferred embodiment, two or more reservoirs. Each reservoir is filled or filled with a gaseous or liquid medium, the medium may, but in the general case does not have to be the same in every reservoir. In each case there is a flexible element which at least partially delimits a reservoir. Preferably, the clamping device is designed so that in at least FPL case number 08F49691-ILT 12 16 12 2009

two reservoirs of pressure can be set independently. In this way it is possible, if necessary, to clamp the joining partners with different power distribution

According to a further aspect, the problem underlying the invention is achieved by a method for laser beam joining of two joining partners, in which the joining partners are braced with each other before and / or during the application of laser radiation, in which the joining partner to be clamped with a flexible element in Contact be brought, and in which by a filled with a gaseous or liquid medium and at least partially producible by the flexible element reservoir pressure generated via the flexible element, a force on at least one of the joining partners to be clamped.

Brief description of the drawings

The present invention will be explained in more detail below with reference to exemplary embodiments in conjunction with the drawings without limiting the scope of protection specified by the claims. Hereby show:

Fig. 1 Schematic representation of a first embodiment of the invention

Fig. 2 Schematic representation of the embodiment of FIG. 1 when generating a pressure in the reservoir

Fig. 3: Schematic representation of a second embodiment of the invention

Fig. 4: Schematic representation of the embodiment of FIG. 3 when generating a pressure in the reservoir

Fig. 5: Schematic representation of a third embodiment of the invention FPL case number 08F49691 ILT 13 16 12 2009

Ways to carry out the invention

1 and 2 show the process sequence for a first embodiment of the device according to the invention. A second joint partner 2 is arranged above a first joint partner 1, joint partner 1 rests on a support element 7 designed as a base plate. The joint partner 1, 2 then becomes a flexible one Element 3 placed as a hollow body formed first limiting means 5 and, designed here as a glass plate, second limiting means 6 together form a "bell" which, the joint partner 1,

2, the flexible element 3 may be formed in particular as shown here as a film, which is fixed only during or by the placement of the bell formed by the limiting means 5, 6 on the Auflagenelemeπt 7 The flexible element

Instead, however, 3 may also be permanently connected to one of the limiting means, eg, the hollow body 5, eg, as a membrane permanently connected to the hollow body, which on lowering the bell formed by the limiting means 5, 6 is lowered onto the joint partners 1, 2 becomes

The limiting means 5, 6 and the support element 7 (which could also be considered as a further limiting means) form or enclose a chamber 9 together. This comprises the reservoir 10 filled or filled with a gaseous or liquid medium, which is accessible from the flexible element 3 and through the Limiting means 5, 6 formed bell is limited and apart from a closable inlet opening 12 for the medium is tight The chamber 9 further comprises a provided for receiving the Fugepartπer 1, 2 area 11 This area 11 is separated from the reservoir 10 by the flexible element 3

2 shows the further course of the process for this first embodiment. According to the invention, a pressure is generated in the reservoir 10. This happens in the present case, by the pressure p of the medium in the reservoir 10 by feeding the medium through the inlet opening 12, for in one of the limiting means, here Thus, the reservoir 10 is expanded in the chamber 9, this is made possible by the FPL case number 08F49691-ILT 14 16 12 2009

Flexibility of the Flexible Element 3. The remaining boundary surfaces of the reservoir 10 are associated with the limiting means 5, 6, which are designed in such a way, in particular sufficiently rigid and suitably fixed that they remain motionless despite the increased pressure in the reservoir 10. For this purpose, for example, as indicated here, a defined force F are introduced via the hollow body 5, which is sufficiently large that the bell formed by the limiting means 5, 6 is not repelled by the base plate 7 and the circumferential seal 4 is sufficiently compressed to to withstand the pressure prevailing in the bell. For example, a pressure of p = 7 bar is set in the chamber and the bell is fixed on the base plate with a force of F = 7000 N, the bell enclosing an area of 10000 mm ² on the base plate.

Thus, in particular, the entire chamber 9 withstands the pressure generated, ie forms a rigid, not displaced by the increased pressure or not displaceable outer boundary for the reservoir 10. The reservoir 10 expands due to the pressure generated at most as far as it Allow chamber 9 and the joining partners 1, 2 therein. The expansion of the reservoir thus ultimately leads to the flexible element 3, or at least a portion of the flexible element 3, fitting snugly against the joining partners 1, 2. The pressure in the reservoir 10 causes a flexible element 3 in the direction of the joining partners 1, 2 driving, symbolized in the figure by arrows force, ie the flexible element 3 is pressed against the joining partners 1, 2. The flexible element 3, here a film of silicone, is designed in this case, in particular so elastic that it adapts to the given contour at a suitably selected pressure. The flexible element 3 thus exerts a homogeneous force to be set via the pressure on the joining partners 1, 2, immediately above all on the upper joining partner 2. This upper joining partner 2 is pressed against the lower joining partner in this manner. Due to the spatially homogeneous distribution of this force, which is exactly adjustable by the pressure control in the reservoir 10, an optimal clamping effect can be achieved without causing undesirable mechanical tension. FPL case number 08F49691-ILT 15 16 12 2009

The tensioning device shown in FIGS. 1 and 2 is suitable and preferably serves as part of a device for laser beam joining. For this purpose, a not shown in the figures laser beam of a laser beam source by means of an optical access, which is here realized by the glass plate 6, coupled into the chamber 9 and on the means of the clamping device - as shown in Fig. 2 - mutually braced joint partner 1, 2 directed. In the case of laser transmission joining, the joining partner 2 is a workpiece that is transparent or at least substantially transparent to the wavelength of the laser beam, so that the laser beam penetrates the latter and subsequently strikes the joining partner 1. This is absorbing for the wavelength of the laser beam or at least in regions, e.g. in the form of an absorbent cover layer, absorbing sufficiently that the resulting heat in the case of plastic welding can cause plasticization of both joining partners 1, 2 and thus a melting. The flexible element 3 is also transparent or at least substantially transparent to the wavelength of the laser radiation used, as well as the medium used in the reservoir 10.

Thus, any area of the interface between the two joining partners 1, 2 and formed by them with the laser beam can be achieved without difficulty.

As an alternative to the example shown in FIGS. 1 and 2, it is also possible for the laser radiation to be coupled in by the support element 7 instead of by a limiting means 6. In this case, the absorption or transmission property would be reversed exactly, so that about the resting on the support member 7 or fixed thereto "lower" joint partner 1 in this case, the transparent joining partner and joining partner 2 of the absorbent joining partners would be. In this embodiment, particular transmissive properties of flexible element 3 and medium would obviously not be required.

Incidentally, it should be emphasized that the devices shown in FIGS. 1 to 5, of course, indicate only a relative arrangement of the individual components relative to one another. Thus, the joining partners 1, 2, for example, obviously not in FPL case number 08F49691 ILT 16 16 12 2009

Gravity senses "rest on the support member 7, ie, if necessary, the support member 7 (inside the jig) within the jig also" up ", for example, be located on the upper side of the chamber 9. It is crucial that the support member 7 is suitable during the tensioning process to oppose an opposing force to the force acting on Fugepartπer 1, 2 force

3 and 4 show the procedure for a second embodiment of the inventive device The difference from the first embodiment consists in the design and fixation of the flexible element 3 This is here permanently connected to one of the limiting means, in this case the hollow body 5 and thus will not necessarily fixed only when or by the placement of the bell formed by the limiting means 5, 6 on the support member 7

Specifically, the fixation consists of a compound of the flexible element 3 with a limiting means 5 along a closed path on the inside of the limiting means 5, while an inlet opening 12 for the medium enclosing the flexible element 3 forms in particular a bag-like structure or a structure which as Can be called fluid cushion, and which can be pressurized from outside of the limiting means 5 by emmission of the medium with pressure

In this exemplary embodiment, the reservoir 10 consists of the volume enclosed by the flexible element 3, otherwise it is limited (apart from the closable inlet opening) exclusively by the flexible element 3. With sufficient pressurization, the sack-like structure or fluid cushion formed by the flexible element 3 will lie fully peripherally the inside of the formed chamber 9 and the joint partners 1, 2 at

Although in this embodiment of the invention, care must be taken that the bell formed by the Begreπzungsmittel 5, 6 does not repel from the base plate 7, such as again by means of a defined force F, which is introduced via the hollow body 5 However, no here precaution FPL case number 08F49691 ILT 17 16 12 2009

be taken to seal the chamber 9, z B in the form of a circumferential seal 4, since the pressurized reservoir 10 is sealed by the flexible member 3 in this case in itself

With regard to the suitability and use of the embodiment of Figure 3 for the laser beam joints apply the statements with respect to FIGS. 1 and 2 in the same sense

A further exemplary embodiment according to the invention is shown in FIG. 5. Like the example shown in FIGS. 3 and 4, it has a flexible element 3 in the form of a bag-like structure or a fluid cushion. According to this further example, the reservoir 10 surrounded by this flexible element 3 is provided with a reservoir The reservoir 10 thus in particular requires no inlet opening and, in particular, due to the surrounding flexible element 3, can be formed completely dense for the medium filled in the production of the reservoir 10 flexible element 3 surrounded reservoir 10 may, but need not be fixed to one of the limiting means 5, 6

Thus, in this embodiment, the pressure is not generated by an increase in the amount of the medium in the reservoir 10. Instead, a means is provided with which the volume of the chamber 9 can be reduced, for example, as shown in Figure 5, the support member 7 relative Sufficient reduction of the chamber 9 leads to a mechanical pressure on the reservoir 10 surrounded by the flexible element 3. Similar to the exemplary embodiment of FIGS. 3 and 4, finally, this process situation is shown in FIG completely surrounded by the flexible element 3 reservoir 10 to the inside of the (reduced in this case) chamber 9 and the joint partners 1, 2 at the acting on reduction of the chamber 9 to the reservoir 10 pressure is in this way on the joint partners 1, 2 By sufficient size of the reservoir 10 it is ensured that the force on the joint partner 1, 2 is spatially homogeneous It is sufficient that the force on the FPL case number 08F49691 ILT 18 16 12 2009

Fugue partner 2 is essentially due only to the homogeneous pressure in the reservoir 10

Figure 6 shows an embodiment of the invention, which is particularly suitable for very extensive joint partners 1, 2 or for an application in which the bracing is to take place with a special pressure distribution

For this purpose, the tensioning device has a plurality of reservoirs 10, 10 ', 10 ". There are one or more flexible elements 3, 3', 3", in particular, in each case a flexible element 3, 3 for each reservoir 10, 10 ', 10 " In the present case, each flexible element 3, 3 ', 3 "is associated with a reservoir 10, 10', 10". In these reservoirs 10, 10 ' , 10 "is in each case a certain pressure generated, so that the flexible elements 3, 3 ', 3" are each brought into contact with a portion of the joint partners to be clamped 1, 2 and thus according to the general inventive concept in each case a force on a portion of at least one of the joint partners 1, 2 to be clamped

The limiting means 5, 6 are designed so that when placing these limiting means 5, 6 on the support element 7 or the joint partners 1, 2 several separate chambers 9, 9 ', 9 "are formed The flexible elements 3, 3', 3" may be different from each other have the various embodiments already described The example shown in Figure 6 illustrates this, by an elastic element 3 "is performed as in the embodiment shown in Figures 1 and 2 as a film, another elastic element 3 as in the in Fig 3 and 4 illustrated embodiment as externally fillable with a medium fluid cushion and finally a third elastic element 3 'according to the embodiment shown in Figure 5 as gefulltes fluid pad, which is not further filled from the outside or is fillable

With the embodiment of Figure 6, it is possible to apply different sections of the joint partners 1, 2 with a mutually different pressure and thus to produce a tension of the joint partners 1, 2 with a defined pressure distribution FPL Case Number 08F49691-ILT 19 16 12.2009

Reservoirs 10, 10 ', 10 "a different medium or a different preheating of the media or be provided.

Of course, more than the three reservoirs 10, 10 ', 10 "or chambers 9, 9', 9" shown can also be provided; in particular, they can also be arranged in a planar structure and not merely in series, as shown here.

FPL case number 08F49691-ILT 20 16 12 2009

LIST OF REFERENCE NUMBERS

1 fugal partner

2 joint partners

3 flexible element

4 seal

5 limiting means

6 transparent limiting means

7 support element

9 chamber

10 reservoir

11 provided for receiving the Fugepartner intended area of the reservoir

12 inlet opening

Claims

FPL case number O8F49691-ILT 21 16 122009Patentansprüche

1. Spanπvorrichtung for clamping two joining partners (1, 2), characterized in that it comprises a filled or filled with a gaseous or liquid medium reservoir (10) which is at least partially bounded by a flexible element (3), wherein the clamping partner (1, 2) can be brought into contact with the flexible element (3) such that a force that can be generated in the reservoir (10) via the flexible element (3) is applied to at least one of the joining partners (1, 2) can be exercised.

2 tensioning device according to the preceding claim, characterized in that the flexible element (3) is elastic, in particular a film or a membrane.

3. Clamping device according to one of the preceding claims, characterized in that the flexible element (3) consists of a polymer, in particular of silicone or Teflon, or contains this.

4. Clamping device according to one preceding claim, characterized in that the flexible element (3) is designed such that its surface topography can be adapted to the contour of a joining partner (1, 2) to be clamped.

5. Clamping device according to one of the preceding claims, characterized in that it comprises one or more limiting means (5, 6) and that the one or more limiting means (5, 6)

^• forms / form a chamber (9) or together with the joining partners (1, 2) to be clamped can form a chamber (9) or

^■ together with the joining partners (1, 2) to be clamped and with a support element (7) on which the joining partners (1, 2) are placed or on the FPL case number 08F49691-ILT 22 16 12 2009

the joint partners (1, 2) can be fixed, can form a chamber (9), such that the chamber (9) is impermeable to the then-flexible element (3)

6. Tensioning device according to the preceding claim, characterized in that the flexible element (3) in the chamber (9) separates the reservoir (10) from a region (11) provided for receiving the joint partners (1, 2)

7. Tensioning device according to one of the preceding claims, characterized by a pressure adjustment device for changing the pressure of the medium in the reservoir (10).

8 clamping device according to the preceding claim, characterized in that the Druckeinstellemπchtuπg comprises means by which the amount of the medium in the reservoir (10) can be increased

9. Clamping device according to one of the two preceding claims, characterized in that the Druckeinstelleinnchtung comprises means, with which the volume of the reservoir (10) can be reduced

10. Clamping device according to one of the preceding claims, characterized by a heating device, with which the temperature of the medium can be increased

11. Clamping device according to one of the preceding claims, characterized in that it comprises two or more reservoirs (10, 10 ', 10 ")

12 tensioning device according to the preceding claim, characterized in that in at least two reservoirs (10, 10 ', 10 "), the pressure can be set independently

13 apparatus for Laserstrahlfugen of two joint partners (1, 2) with a laser beam source and a Spannvoπchtung according to any one of the preceding claims, characterized in that the clamping device has an optical access (6) through which FPL case number O8F49691-ILT 23 16.12 2009

an exposure of the joining partners (1, 2) with radiation of the laser beam source is made possible.

14. Device according to the preceding claim, characterized in that the flexible element (3) for the radiation of the laser beam source is substantially transparent.

15. A method for laser beam joining of two joining partners (1, 2), in particular with a device according to one of the two preceding claims, wherein the joining partners (1, 2) before and / or during the application of laser radiation are clamped together, characterized in that the joining partners (1, 2) to be clamped are brought into contact with a flexible element (3), and that by a reservoir (10) filled with a gaseous or liquid medium and at least partially surrounded by the flexible element (3). producible pressure via the flexible element (3) a force is exerted on at least one of the joining partners (1, 2) to be clamped.

16. A method for laser beam joining of two joining partners (1, 2) according to the preceding claim, characterized in that at least one of the joint partners to be clamped (1, 2) is heated by the medium.