Hold-down tool

Abstract

The invention relates to a hold-down tool (9) for a laser welding system, comprising a tubular hollow body (20) which has a lateral surface (26) that is designed to be closed in a laminar manner at least in some sections, and a tool insert (40) as a contact element which is flexibly held on the hollow body (20) and provides a tool contact surface (53) for bringing the tool insert (40) into contact with a first contact component (1) to be welded.

Description

[0001] Hold-down tool

[0002] The invention relates to a hold-down tool for a laser welding system.

[0003] Conventional laser welding systems have been used for many years, particularly for bonding metallic contact components. However, these systems currently have only limited capabilities for compensating for the shape and position tolerances of the contact components.

[0004] The object of the present invention is to provide an improved hold-down tool for a laser welding system.

[0005] To achieve this object, the invention has the features of patent claim 1. Accordingly, a hold-down tool for a laser welding system comprises a tubular hollow body which has a jacket surface that is at least partially closed, and a tool insert. The tool insert is held flexibly on the hollow body and, as a contact element of the hold-down tool, provides a tool contact surface for applying the tool insert to a first contact component to be welded. The particular advantage of the invention is that the laser beam for welding the contact components can be guided through the tubular hollow body to a connection point, and the hold-down tool and the tool insert can simultaneously compensate for shape and position tolerances of the contact components to be welded.The compensation of shape and position tolerances and, in particular, the flat pressing of the contact components together promotes reliable and flawless welding. Furthermore, the contact of the tool insert, which is held flexibly relative to the hollow body, against the contact component facing the hold-down tool, especially the upper one to be welded, prevents contamination of the surrounding area during the weld process.

[0006] The hold-down tool, with its tubular hollow body on the one hand and the tool insert held flexibly against the hollow body on the other, thus performs a multiple function. It shields the laser beam, thus counteracting any undirected reflection of the laser beam, which is particularly critical from a safety perspective. Furthermore, by pressing the hold-down tool against the upper contact component to be welded, shape and position tolerances of the contact components can be compensated. The flexibility between the tool insert and the hollow body counteracts mechanical damage to the contact components to be connected. This is particularly important for sensitive electronic components. Finally, the hold-down tool, with its tubular hollow body and the tool insert held flexibly within it, mechanically shields the weld point.This also prevents environmental contamination from splashes, for example, caused by welding.

[0007] According to a preferred embodiment of the invention, the tool insert is resiliently mounted on the hollow body. It has advantageously been shown that the resilient mounting of the tool insert on the hollow body can be implemented both inexpensively and robustly. Corresponding hold-down tools are therefore durable and, at the same time, highly economical. According to a further development of the invention, a pressure spring is provided for the resilient mounting of the tool insert on the hollow body. The pressure spring is implemented in particular as an internal pressure spring which is encompassed by the hollow body and / or the tool insert. The provision of the internal pressure spring advantageously provides mechanical protection for the pressure spring against external influences. This prevents damage to the pressure spring.

[0008] According to a further development of the invention, the tool insert is designed in the manner of a hollow spherical ring segment. It therefore has a spherical ring segment surface that can be placed against a support surface provided by the hollow body and shaped to correspond to the spherical ring segment surface. Furthermore, the flexible or resilient association of the tool insert with the hollow body is realized such that the tool insert is pivotably arranged relative to the hollow body. Advantageously, by providing the spherical ring segment surface and the support surface, as well as pivotably arranging the tool insert with the hollow body, the hold-down tool, which is typically movable along a vertical axis, can be applied to the upper contact component to be welded even if the upper contact component is inclined to the horizontal.The ball ring segment surface and the corresponding support surface of the hollow body ensure that the tool insert always rests flat against the hollow body. This ensures maximum stability and robustness regardless of the pivoting position.

[0009] According to a further development of the invention, the tool insert is pivoted relative to the hollow body about a pivot point which, in a contact position in which the tool contact surface of the tool insert is in surface contact with a surface of the first contact component, is formed on the surface of the first contact component. Advantageously, this, together with the flexible and pivotable association of the tool insert with the hollow body of the hold-down tool, ensures that the hold-down tool can be placed flat against the upper contact component to be welded in an oblique orientation, without a relative movement in the sense of rubbing or sliding occurring between the hold-down tool or the tool insert of the hold-down tool having the tool contact surface on the one hand and the upper contact component on the other.By avoiding relative movement, the mechanical stress on the surface of the contact components is reduced and damage to, for example, electronic components mounted on the surface of the contact component is prevented.

[0010] According to a further development of the invention, the tool contact surface of the tool insert is annular or flat. The annular, preferably circumferentially closed and flat tool contact surface ensures a uniform and distributed force application when the hold-down tool is applied to the upper contact component to be welded. Furthermore, this results in improved shielding of the weld point, both with respect to the reflected laser beam and with respect to mechanical contamination, which can arise, for example, from splashes released from the melt.

[0011] According to a further development of the invention, the tool insert includes a protrusion protruding from the hollow body, the protrusion providing the tool contact surface and thus facing the upper contact component to be welded. The provision of the protrusion protruding from or projecting from the hollow body improves the handling of the blank holder tool. In particular, small, delicate joints can be approached or formed by the provision of the protrusion. The protrusion thus forms a tapered portion of the tool insert toward the contact components.

[0012] According to a further development of the invention, the hollow body is constructed in multiple parts. It comprises a shell part providing the annular surface and a support part providing the support surface for the tool insert. Optionally, a cap can also be provided, which also partially encompasses the support part or the tool insert of the hold-down tool. The multi-part design of the hollow body advantageously results in structural and manufacturing advantages. In particular, the support surface can be manufactured as part of the support part, separate from the shell part, and the support part can be subsequently connected to the other parts of the hollow body.

[0013] According to a further development of the invention, the tool insert is constructed in multiple parts. For example, it provides an interchangeable body providing the tool contact surface, which is interchangeably mounted on an attachment component of the tool insert. Advantageously, the multi-part tool insert with the interchangeable body providing the tool contact surface can offer significant cost advantages during ongoing operation. With increasing wear, for example in the area of ​​the tool contact surface, only the interchangeable body of the tool insert needs to be replaced, while the attachment component and other components of the tool insert can continue to be used. The interchangeable body can therefore be designed as a cost-effective wear part.

[0014] According to a further development of the invention, the tool insert provides an upper part that provides the ball ring segment surface. Unlike the interchangeable body, the upper part is preferably not designed as a wear part of the tool insert or hold-down device. Regular replacement of the upper part with the ball ring segment surface, which is complex to manufacture, is then unnecessary.

[0015] According to a further development of the invention, the upper part of the tool insert serves as an attachment component for the interchangeable body. The tool insert can then, for example, provide two essential functional components, namely the upper part and the interchangeable body.

[0016] According to a further development of the invention, the interchangeable body is fastened to the attachment component in a force-fitting or form-fitting manner. In particular, a quick-release mechanism can be provided for fastening the interchangeable body to the attachment component. For example, a bayonet lock can be provided as a quick-release lock for tool-free fastening of the interchangeable body to the attachment component. For example, circumferential grooves can be provided on the attachment component on the one hand and the interchangeable body on the other, into which an annular, elastic retaining spring is inserted. The retaining spring can be designed to be flexible in such a way that the interchangeable body can be connected to the attachment component and secured thereto by means of the retaining spring without the need for tools. The retaining spring engaging in the circumferential grooves defines the relative position of the interchangeable body and the attachment component.

[0017] According to a further development of the invention, a laser channel, through which the laser beam can be guided to the upper contact component to be welded, extends through the tubular hollow body and the tool insert. In particular, it can be provided that the laser channel extends through the casing part and / or the support part of the hollow body as well as the upper part, the attachment component, and / or the interchangeable body of the tool insert. A longitudinal center axis of the hold-down tool can run through the laser channel.

[0018] According to a further development of the invention, the hold-down tool provides a gas channel that serves to guide a gas as a purge gas, for example, air or an inert protective gas, preferably argon or nitrogen, to a working chamber formed on the tool insert, which is adjacent to the upper contact component. The working chamber, which can be formed, for example, in the area of ​​the attachment, provides a gas outlet opening as the end of the gas channel. The gas channel itself preferably extends through the hollow body on the one hand and the tool insert on the other.

[0019] According to a further development of the invention, the gas supplied to the work chamber via the gas channel can be discharged via the laser channel. For example, the gas can be extracted via the laser channel.

[0020] For example, ambient air can enter the tool insert or the work area via inlet openings provided on the tool insert. In particular, the ambient air can be drawn in through the inlet openings, while the gas supplied via the gas duct is extracted. An extraction device can thus extract the gas supplied via the gas duct, the ambient air supplied via the inlet openings, and / or the gas-ambient air mixture. The inlet openings are preferably provided above the outlet opening of the gas duct and / or the attachment, i.e., at a greater distance from the tool contact surface.

[0021] According to a further development of the invention, the tool insert or parts thereof, in particular the interchangeable body of the tool insert, are formed from an electrically insulating material, at least in an area comprising the tool contact surface. Preferably, a technical ceramic can be used as the material.

[0022] Further advantages, features, and details of the invention can be gathered from the further subclaims and the following description. The features mentioned therein may be essential to the invention individually or in any combination. The drawings serve merely as examples to clarify the invention and are not limiting in nature.

[0023] They show:

[0024] Fig. 1 is a schematic diagram of a laser welding arrangement with a hold-down tool with an ideally perpendicular orientation of a working plane to a longitudinal center axis of the hold-down tool and extension of the contact components to be welded by laser in the working plane,

[0025] Fig. 2 shows a first embodiment of a hold-down tool with a hollow body and a tool insert in a perspective view obliquely from below,

[0026] Fig. 3 the hold-down tool in the first embodiment in a perspective view obliquely from above,

[0027] Fig. 4 is a first longitudinal sectional view of the hold-down tool in the first embodiment, Fig. 5 is a second longitudinal sectional view of the hold-down tool in the first embodiment rotated by 90° to the first longitudinal sectional view,

[0028] Fig. 6 is a perspective top view of an upper part of the tool insert of the hold-down tool in the first embodiment,

[0029] Fig. 7 is a perspective bottom view of the upper part of the tool insert according to Fig. 6,

[0030] Fig. 8 is a perspective top view of a support part of the hollow body of the hold-down tool facing the tool insert in the first embodiment,

[0031] Fig. 9 is a perspective bottom view of the support part of the hollow body according to Fig. 8,

[0032] Fig. 10 shows a first working position of the hold-down tool in the first embodiment during laser welding of a first contact component oriented in the working plane,

[0033] Fig. 11 shows a second working position of the hold-down tool in the first embodiment during laser welding of a first contact component oriented in the working plane,

[0034] Fig. 12 shows a first working position of the hold-down tool in the first embodiment during laser welding of a first contact component oriented obliquely to the working plane and a second contact component extending in the working plane,

[0035] Fig. 13 shows a second working position of the hold-down tool in the first embodiment during laser welding of the first contact component oriented obliquely to the working plane and the second contact component extending in the working plane. Fig. 14 shows a third working position of the hold-down tool in the first embodiment during laser welding of the first contact component oriented obliquely to the working plane and the second contact component extending in the working plane.

[0036] Fig. 15 shows a fourth working position of the hold-down tool in the first embodiment during laser welding of the first contact component previously oriented obliquely to the working plane and the second contact component extending in the working plane,

[0037] Fig. 16 shows a first working position of the hold-down tool in the first embodiment during laser welding of two contact components that are oriented obliquely to the working plane and spaced apart from each other,

[0038] Fig. 17 shows a second working position of the hold-down tool in the first embodiment during laser welding of the two contact components which are oriented obliquely to the working plane and spaced apart from each other,

[0039] Fig. 18 shows a third working position of the hold-down tool in the first embodiment during laser welding of the two contact components which are oriented obliquely to the working plane and were previously spaced apart from each other,

[0040] Fig. 19 a longitudinal section through the hold-down tool in a second embodiment with a tool insert in an assembly position,

[0041] Fig. 20 a longitudinal section through the hold-down tool in a second embodiment with a tool insert in a removal position,

[0042] Fig. 21 is a perspective view of the hold-down tool in the second embodiment with the tool insert in the assembly position, Fig. 22 is a perspective view of the hold-down tool in the second embodiment with the tool insert in the removal position,

[0043] Fig. 23 a first longitudinal sectional view of the hold-down tool in a third embodiment and

[0044] Fig. 24 is a second longitudinal sectional view of the hold-down tool in the third embodiment, rotated by 90° to the first longitudinal sectional view.

[0045] Laser welding systems with a laser source 3 as the energy source are used, among others, for welding metallic contact components 1, 2 in electrical engineering, battery technology, or power electronics. A laser beam 7 provided by the laser source 3 is typically guided through an optical fiber to an optic 4 located above the working plane 5. The optic 4 is aligned such that the axis of symmetry 6 of the focused laser beam 7 is collinear with a typically vertically extending symmetry or longitudinal center axis 8 of a hold-down tool 9 of the laser welding system and perpendicular to the working plane 5 (see Fig. 1).

[0046] The contact components 1, 2 to be welded, or their contact surfaces, ideally extend in the working plane 5 or are parallel to it. Facing contact surfaces of the contact components 1, 2 run plane-parallel to each other. The hold-down tool 9 then serves to press the contact components 1, 2 together without a gap and to shield the weld. Particularly with the preferred deep penetration welding method, the contact components 1, 2 to be welded must lie flush on top of each other. There must be no gap between the contact components 1, 2; otherwise, a high-quality, low-spatter or spatter-free weld is not possible.

[0047] The contact points of the contact components 1, 2 to be connected can, if the topology permits, be aligned so that they are directly connected to one another. In this case, no additional conductors (with round or rectangular cross-sections) are required to establish an electrically conductive connection. If the number of contact points is large or the contact points are spatially distributed, a direct connection of the contact points is therefore not possible. Additional conductors are then required, which must be brought to the contact points and connected there to the contact points of the contact components 1, 2 using a suitable connection technology.To avoid having to bring the conductors individually to the respective contact points, it is advisable to combine the required connections in an additional contact system, similar to a printed circuit board, which contains all the lines for connecting the individual components as a first contact component 1. Such contact systems are used, for example, for wiring or contacting larger battery modules or other matrix-arranged contact components, which are to be connected to the first contact component 1 as a second contact component 2. At the locations where the contact points of the module to be electrically contacted are located, the contact system has cutouts from which a contact strip emerges and can be connected to the module's contact.

[0048] The contact system, for example, is designed cost-effectively as a stamped sheet metal part and is therefore subject to tolerances or is not perfectly flat. Furthermore, in practice, it is observed that the individual battery cells of a battery module, for example, are assigned to each other with tolerances. These tolerances must then also be compensated for during the production of the welded joint.

[0049] In order to produce the integral welded connection of the contact components 1, 2, the hold-down tool 9 provides a laser channel 10 for the laser beam 7. The hold-down tool 9, with a tool contact surface 53 facing away from the optics 4, is placed flat against the first, upper contact component 1 facing the optics 4 and is dimensioned and positioned such that the focused laser beam 7 passes through the laser channel 10 and strikes the first contact component 1 on the end face of the hold-down tool 9 facing away from the optics 4. The flat contact of the hold-down tool 9 against the upper, first contact component 1 and the at least partially closed lateral surface 26 of the hold-down tool 9 have a shielding effect and ensure that molten material does not splash uncontrollably during welding.The hold-down tool 9 thus prevents contamination of the environment and counteracts later malfunctions caused by the formation of defective, unintentional, electrically conductive contacts.

[0050] The modules can contain contact points or surfaces at different heights. The hold-down tool 9 is firmly connected to an axis system of the laser welding system, which is mounted for vertical movement. The hold-down tool 9 can therefore reach contact points or surfaces at different heights. The orientation of the hold-down tool 9 is typically perpendicular to the working plane 5. Furthermore, it can be provided that the hold-down tool 9 is moved and positioned horizontally via a suitable xy kinematics of the laser welding system.

[0051] In the present case, the optics 4 can be controlled by a controller 11 of the laser welding system and is configured to move the focused laser beam 7 along the contact components 1, 2 and to form a linear or planar weld.

[0052] In practice, it is often observed that the contact elements 1, 2 are not arranged exactly in the working plane 5 and / or do not extend plane-parallel to one another. For example, due to their shape, the contact elements 1, 2 may only touch at a few points and / or be arranged obliquely to the working plane 5. In this case, a flat contact of the contact components 1, 2 against one another and / or a flat contact of the hold-down tool 9 against the first, upper contact component 1 is not easily possible. Rather, the contact components 1, 2 must be aligned with one another and / or placed flat against one another in order to ensure a zero gap and thus produce a high-quality welded connection.In order to achieve this, the hold-down tool 9 according to the invention provides a tubular hollow body 20, that is to say having a through-hole for the laser beam 7, and a tool insert 40 with the tool contact surface 53, which is held on the hollow body 20 in a flexible manner with respect to the latter.

[0053] The following explains the possible design and function of the hold-down tool 9 using three exemplary embodiments. A first embodiment of the hold-down tool 9 is shown in Figs. 2 to 5. Accordingly, the hold-down tool 9 comprises, as essential functional components, the hollow body 20 with a casing part 25, a support part 21, and a cap 30, as well as the tool insert 40 with an upper part 44 and an interchangeable body 50. The upper part 44 of the tool insert 40 is shown in detail in Figs. 6 and 7. Figs. 8 and 9 show the support part 21 of the hollow body 20.

[0054] The hollow body 20 provides the shell part 25 with a closed shell surface 26. A portion of the laser channel 10 extends through the shell part 25 in the direction of the longitudinal center axis 8 of the blank holder tool 9.

[0055] The support part 21 is assigned to the casing part 25 in the region of an end face facing the tool insert 40 or the first, upper contact component 1. The support part 21 provides a support surface 22 resembling a spherical ring segment, against which the tool insert 40 can be placed. The support part 21 is secured to the hollow body 20 by screws 24 that engage in through-holes 23 in the support part 21.

[0056] Furthermore, the cap 30 is attached to the casing part 25 of the hollow body 20. The cap 30 surrounds the support part 21 with the support surface 22. Furthermore, the cap 30 partially surrounds the tool insert 40. Screws 31 are used to secure the cap 30 to the hollow body 20.

[0057] Like the hollow body 20, the tool insert 40 is constructed in several parts. It comprises the upper part 44 and the interchangeable body 50, which is secured to the upper part 44 by screws 56. To accommodate the screws 56, the upper part 44 provides a total of three blind holes 46 distributed in a circumferential direction.

[0058] The upper part 44 provides, on an upper side facing the support part 21 of the hollow body 20, a ball ring segment surface 48 which is shaped like a ball ring segment surface corresponding to the support surface 22 of the support part 21. On an underside opposite the upper side, three ball seats 49 are formed on the upper part 44 of the tool insert 40, arranged in a circumferential direction. The ball seats 49 each have a substantially wedge-shaped groove projecting radially away from the longitudinal center axis 8 of the hold-down tool 9. They serve to support the tool insert 40 against the cap 30 of the hollow body 20 via three support balls 14. The cap 30 has three through holes 33 opposite the ball seats 49 as a receptacle for the support balls 14.

[0059] The interchangeable body 50 is positioned against an insert shoulder 43 of the upper part 44 of the tool insert 40 and thus assumes a fixed position relative to the upper part 44 of the tool insert 40. It provides a tapered attachment 59, which protrudes beyond the cap 30 of the hollow body 20. The attachment 59 of the interchangeable body 50 provides the tool contact surface 53. The tool contact surface 53 is flat and surrounds the attachment 59 in a circumferential ring.

[0060] In order to secure the tool insert 40 to the hollow body 20 in a rotationally secure manner, three outwardly projecting arms 58 are formed on the tool insert 40, regularly spaced in the circumferential direction. The arms 58 are guided through three recesses 32 formed on the shell side of the cap 30 of the hollow body 20 with such play that the tool insert 40 can be pivoted relative to the hollow body 20 or the cap 30.

[0061] The tool insert 40 is assigned to the hollow body 20 in the direction of the longitudinal center axis 8 of the hold-down tool 9 by means of a pressure spring 13, which, as an internal pressure spring 13, is encompassed on the outside by the casing part 25, the support part 21, and the cap 30 of the hollow body 20. The pressure spring 13 is applied with two opposite end faces against a shoulder 28 formed on the casing part 25 of the hollow body 20.

[0062] Furthermore, the pressure spring 13 rests against a further shoulder 47 formed on the upper part 44 of the tool insert 40. The pressure spring 13 is dimensioned such that, in a non-contact position of the hold-down tool 9 shown in Figs. 2 to 5, the tool insert 40 is arranged at a distance from the support part 21 of the hollow body 20 in the direction of the longitudinal center axis 8 and is simultaneously supported against the cap 30 via the support balls 14, which engage in the through-bores 33 of the cap 30 and are leaned against the ball seats 49. The laser channel 10, which runs in the direction of the longitudinal center axis 8 of the hold-down tool 9, is guided through the entire hollow body 20 with the casing part 25, the support part 21, and the cap 30. Furthermore, the laser channel 10 is guided through the tool insert 40 with the upper part 44 and the interchangeable body 50.The laser channel 10 provides a laser inlet opening 27 on the end face of the casing part 25 of the hollow body 20 and a laser outlet opening 54 surrounded by the tool contact surface 53 in the area of ​​the attachment 59. In the area of ​​the attachment 59, the laser channel 10 simultaneously defines a working space 51. In the area of ​​the working space 51, the laser beam 7 strikes the first, upper contact component 1.

[0063] In addition to the laser channel 10, the hold-down tool 9 includes a gas channel 12. The gas channel 12 serves to supply a gas as a purge gas to the work chamber 51. The work chamber 51 provides a gas outlet opening 52 as the end of the gas channel 12. The gas is returned, for example, through the laser channel 10. For this purpose, in particular, an extraction device (not shown in the drawings) can be provided.

[0064] The extraction device can also be used to draw in ambient air flowing in through inlet openings 62 provided on the tool insert 40 and through the laser channel 10.

[0065] 10 and 11 illustrate the operation of the hold-down device 9 in the first embodiment when it is placed on a flat surface of the first contact component 1 extending parallel to the working plane 5. The hold-down device 9, which in the non-contact position is initially provided at a distance from the first contact component 1, is lowered with the attachment 59 of the tool insert 40 leading in the direction of the first contact component 1. The longitudinal center axis 8 of the hold-down device 9 is oriented perpendicular to the working plane 5. As soon as the tool contact surface 53 of the tool insert 40 is in surface contact with the surface of the first contact component 1 (contact position) and the hollow body 20 of the hold-down tool 9 is lowered further, the tool insert 40 springs in.The pressure spring 13 is compressed until the tool insert 40, with the ball ring segment surface 48, rests against the support surface 22 of the support part 21 and a contact position is reached. At the same time, the ball seats 49 are released from the support balls 14.

[0066] As soon as the hold-down device 9 has been moved from the non-contact position shown in Fig. 10 to the contact position shown in Fig. 11, welding can begin. For this purpose, the gas can be supplied via the gas channel 12 and enter the working chamber 51 through the gas outlet opening 52. Additionally, the laser source 3 is activated, so that the laser beam 7 passes through the laser channel 10 and strikes the first contact component 1. This is then melted by the energy of the laser beam 7 and bonded to the second contact component 2 (not shown here).

[0067] If the first contact component 1 does not lie flat against the second contact component 2 and the first contact component 1 does not extend perpendicular to the longitudinal center axis 8 of the hold-down device 9, a gap is formed between the first and second contact components 1, 2. This initial situation is shown in Fig. 12. In order to weld the contact components 1, 2 together safely and reliably despite the unfavorable arrangement of the contact components 1, 2, the hold-down tool 9 is lowered in the first step until contact is made with the first contact component 1 (cf. Fig. 13). Subsequently, due to the contact and the material stiffness of the first contact component 1, the tool insert 40, of which only the attachment 59 protrudes from the cap 30 and is visible in Fig. 14, is pivoted relative to the tool longitudinal axis 8 such that the tool insert 40 is placed flat against the first contact component 1 with the tool contact surface 53.From the moment the tool contact surface 53 makes flat contact with the surface of the first contact components 1, the latter are in the contact position. Subsequently, during further lowering, the first contact component 1 is pressed flat against the second contact component 2 using the hold-down tool 9. The tool insert 40 pivots back, forming the flat contact between the contact components 1, 2 shown in Fig. 15. Welding can now be carried out as described above.

[0068] 16 to 18 show an initial configuration for laser welding, in which the contact elements 1, 2 do not extend in the working plane 5 or are not oriented perpendicular to the longitudinal center axis 8 of the hold-down tool 9, and in which a gap is additionally formed between the contact components 1, 2. As before, the hold-down tool 9 is lowered in a first step until a first contact is formed between the attachment 59 of the tool insert 40 and the first contact component 1. The tool insert 40 then pivots such that the tool contact surface 53 rests flat against the first contact component 1, and presses the first contact component 1 against the second contact component 2 until the gap between the contact components 1, 2 is closed. With the tool insert 40 in the inclined arrangement, the welding can now take place.The tool insert 40 is supported by the ball ring segment surface 48 in a known manner against the support surface 22 of the support part 21. A maximum pivoting angle is functionally necessarily matched to a transverse dimension of the laser channel 10 so that the laser beam 7 is directed despite the inclination of the.

[0069] Tool insert 40 passes through the laser channel 10 and impinges unhindered on the first contact component 1.

[0070] While the interchangeable body 50 according to the first embodiment of the hold-down tool 9 is screwed to the upper part 44 of the tool insert 40 and can therefore only be replaced with the aid of a tool, a second embodiment of the hold-down tool 9, shown in Figs. 19 to 22, shows a tool insert 40 in which an interchangeable body 50 is fixed to the upper part 44 of the tool insert 40 via a retaining spring 15 and can be replaced without tools. The retaining spring 15 is an annular spring that is elastic and deformable in the circumferential and radial directions, so that the interchangeable body 50 can be inserted into the upper part 44 by deforming the retaining spring 15. The retaining spring 15 engages in two circumferential retaining spring grooves 45, 60 formed correspondingly on the interchangeable body 50 and the upper part 44.

[0071] The tool-free replacement of the interchangeable body 50 allows for a worn and / or contaminated interchangeable body 50 to be quickly replaced during production. The use of the hold-down tool 9 in the second embodiment is therefore optimized for high productivity and short downtimes. The relative assignment of the interchangeable body 50 to the upper part 44 in the direction of the longitudinal center axis 8 is realized by an end face 61 formed on the interchangeable body 50 and a correspondingly designed insert shoulder 43 of the upper part 44.

[0072] Figs. 23 and 24 show a third embodiment of the hold-down tool 9. Here, the tool insert 40 is formed in one piece. The one-piece tool insert 40 provides the attachment 59, a portion of the gas channel 12, and the ball ring segment surface 48, and also provides the shoulder 47 against which the pressure spring 13 is applied. In this respect, it interprets the functions of the support part 21 and the interchangeable body 50 of the tool insert 40 of the hold-down tool 9 according to the first embodiment.

[0073] Identical components and component functions are identified by the same reference symbols.

[0074] List of reference symbols

[0075] 1 contact component

[0076] 2 Contact component

[0077] 3 Laser source

[0078] 4 Optics

[0079] 5 Working level

[0080] 6 axis of symmetry

[0081] 7 focused laser beam

[0082] 8 Longitudinal center axis

[0083] 9 hold-down tool

[0084] 10 laser channels

[0085] 11 Control

[0086] 12 Gas duct

[0087] 13 Pressure spring

[0088] 14 Support ball

[0089] 15 Retaining spring

[0090] 20 hollow bodies

[0091] 21 Support part

[0092] 22 Support surface

[0093] 23 through-holes

[0094] 24 Screw (for support part)

[0095] 25 Sheath part

[0096] 26 Shell surface

[0097] 27 Laser entrance opening

[0098] 28 Shoulder (for pressure spring)

[0099] 30 cap

[0100] 31 Screw (for cap)

[0101] 32 recess (for arm)

[0102] 33 Through hole (for ball)

[0103] 40 tool insert

[0104] 43 Insert shoulder upper part

[0105] Retaining spring groove

[0106] blind hole

[0107] Shoulder (for pressure spring)

[0108] Ball ring segment surface

[0109] ball seat

[0110] Interchangeable bodies

[0111] workspace

[0112] Gas outlet opening

[0113] Tool contact surface

[0114] Laser exit aperture

[0115] screw

[0116] arm

[0117] Intent

[0118] Retaining spring groove

[0119] frontal surface

[0120] Entrance opening

Claims

Patent claims 1. A hold-down tool (9) for a laser welding system comprising a tubular hollow body (20) which has a jacket surface (26) which is at least partially closed in planar form, and a tool insert (40) as a contact element which is held resiliently on the hollow body (20) and provides a tool contact surface (53) for placing the tool insert (40) on a first contact component (1) to be welded.

2. Hold-down tool (9) according to claim 1, characterized in that the tool insert (40) is resiliently mounted on the hollow body (20).

3. Hold-down tool (9) according to claim 1 or 2, characterized in that the tool contact surface (53) is annular and / or flat.

4. Hold-down tool (9) according to one of claims 1 to 3, characterized in that the tool insert (40) is designed as a hollow ball ring segment and / or hollow ball ring segment-like.

5. Hold-down tool (9) according to claim 4, characterized in that the tool insert (40) formed in the manner of a hollow spherical ring segment has a spherical ring segment surface (48), that the hollow body (20) provides a support surface (22) shaped corresponding to the spherical ring segment surface (48), against which support surface the tool insert (40) can be placed with the spherical ring segment surface (48), and that the tool insert (40) is arranged to be pivotable relative to the hollow body (20), wherein the tool insert (40) is preferably pivoted about a pivot point which, in a contact position in which the tool contact surface (53) of the tool insert (40) is in planar contact with a surface of the first contact component (1), is formed on the surface of the first contact component (1).

6. Hold-down tool (9) according to one of claims 1 to 5, characterized in that the tool insert (40) is designed in several parts.

7. Hold-down tool (9) according to claim 6, characterized in that the tool insert (40) provides an interchangeable body (50) held interchangeably on an attachment component of the tool insert (40), wherein the interchangeable body (50) provides the tool contact surface (53).

8. Hold-down tool (9) according to claim 7, characterized in that the interchangeable body (50) is fixed to the attachment component in a force-fitting and / or form-fitting manner.

9. Hold-down tool (9) according to claim 7 or 8, characterized in that the tool insert (40) provides an upper part (44), wherein the upper part (44) serves as the attachment component and provides the ball ring segment surface (48).

10. Hold-down tool (9) according to one of claims 1 to 9, characterized in that the tool insert (40) provides an attachment (59) projecting relative to the hollow body (20) and that the attachment (59) provides the tool contact surface (53).

11. Hold-down tool (9) according to one of claims 1 to 10, characterized in that the tool insert (40) is supported relative to the hollow body (20) via at least one supporting ball (14) and / or that the tool insert (40) on the one hand and the hollow body (20) on the other hand each provide a number of ball seats (49) and / or through-bores (33) corresponding to a number of supporting balls (14).

12. Hold-down tool (9) according to one of claims 2 to 11, characterized in that a pressure spring (13) is provided for resiliently mounting the tool insert (40) on the hollow body (20) and / or that the pressure spring (13) is realized as an internal pressure spring (13) which is encompassed by the hollow body (20) and / or the tool insert (40).

13. Hold-down tool (9) according to one of claims 1 to 12, characterized in that the hollow body (20) is formed in several parts and / or that the hollow body (20) provides a support part (21), wherein the support part (21) provides the support surface (22) shaped corresponding to the ball ring segment surface (48).

14. Hold-down tool (9) according to claim 13, characterized in that the hollow body (20) provides a casing part (25) providing the casing surface (26) and / or a cap (30) and / or that the cap (30) encompasses the support part (21) of the hollow body (20) and / or the tool insert (40) at least in sections.

15. Hold-down tool (9) according to one of claims 1 to 14, characterized in that a gas channel (12) is provided, via which a gas can be supplied to a working space (51) formed on the tool insert (40), and / or that the gas channel (12) extends through the hollow body (20) and / or the tool insert (40).

16. Hold-down tool (9) according to one of claims 1 to 15, characterized in that a laser channel (10) is provided through which a laser beam can be guided to the contact component (1) to be welded, and / or that the laser channel (10) extends through the hollow body (20) and / or the tool insert (40).

17. Hold-down tool (9) according to one of claims 1 to 16, characterized in that the tool insert (40) and / or the interchangeable body (50) of the tool insert (40) and / or the hollow body (20) is made of an electrically insulating material and preferably of a technical ceramic, at least in a region having the tool contact surface (53).

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