Method and device for joining joining partners to form a component

Abstract

Method for joining joining partners to form a component (8, 10, 12) by means of laser welding, comprising the following steps (a) equipping a first component holder (1) with a first joining partner (6) and holding the first joining partner (6) by the latter; (b) equipping a second component holder (3) with a second joining partner (7) and holding the second joining partner (7) by the latter; (c) heating the joining surfaces of the joining partners (6, 7) arranged in the component receptacles (1, 3) by means of an irradiation unit (5) having at least one laser beam source and designed to emit a first radiation and a second radiation, wherein the first component receptacle (1) and the second component receptacle (3) are each arranged in a heating position in which the joining partners (6, 7) are arranged relative to the irradiation unit (5) in such a way that the joining surface of the first joining partner (6) intended for joining can be heated by the first radiation and the joining surface of the second joining partner (7) intended for joining can be heated by the second radiation; (d) arranging the component holders (1, 3) with the joining partners (6, 7) held thereby in a joining position in which the joining surfaces of the joining partners (6, 7) are arranged opposite one another; (e) joining the joining partners (6, 7) to form a first component (8), in particular comprising a step of moving the component holders (1, 3) towards one another; (f) Detaching the second joining partner (7) from the second component receptacle (3) and holding the first component (8) in the first component receptacle (1); characterized by repeating steps (b) to (f) at least once, wherein the second component receptacle (3) is equipped with a further joining partner (9) and is joined to form a second component (10) with the first component (8) remaining in the first component receptacle (1), and wherein the heating position of the first component receptacle (1) is selected as a function of the component (8, 10, 12) arranged in the first component receptacle (1) and / or as a function of the shape of the component (8, 10, 12) to be joined, wherein the new heating position of the first component receptacle (1) differs from the preceding heating position of the first component receptacle (1).

Description

[0001] The invention relates to a method for joining joining partners to form a component by means of laser welding according to the preamble of claim 1 and to a device for joining joining partners to form a component by means of laser welding according to claim 17.

[0002] From the prior art according to DE 10 2019 215 516 B4, a device for the material-to-material joining of two plastic workpieces by means of laser welding, which is also referred to as plastic welding, is known. The device comprises two holders for arranging one of the two workpieces to be joined together to form a component in each of these holders. In a first position of the holders, the workpieces arranged in the holders are heated on the respective surfaces intended for joining using laser energy emitted by a beam source. By a controlled movement, the holders are then moved to a second position in which the joining surfaces of the workpieces face each other parallel and spaced apart. The holders are then moved towards each other in a direction perpendicular to the joining surfaces into a third position in which the workpieces are brought into contact.After the workpieces have been joined to form the component, the fixtures containing the produced component are returned to the first position in one of the two fixtures, and the component is then removed from this fixture. The described fixture movements are specifically controlled by a positively guided cam control.

[0003] Furthermore, DE 10 2021 209 203 B3 discloses a device for joining two joining partners, comprising a first and a second component holder, each of which holds a joining partner. The first component holder is rotatable about a first axis of rotation, and the second component holder is rotatable about a second axis of rotation, which is perpendicular to the first axis of rotation. Specifically, the component holders rotate between a loading and unloading position, in which the joining partners are loaded and unloaded, a heating position, in which the joining surface of the respective joining partner is heated, and a joining position, in which the joining partners are joined together. The two joining partners connected to form a workpiece remaining in one of the component holders are then removed from the workpiece in the unloading position.

[0004] Another device for joining two plastic molded parts, wherein the device has a heat source for generating laser beams and the plastic molded parts are joined together after heating, is known from DE 10 2008 042 663 A1.

[0005] From DE 10 2016 210 086 A1, a method for producing a structural component for an aircraft or spacecraft is also known, in which a skin element is formed in a forming tool part and stringers or frames are then welded to the skin element.

[0006] Based on the above-mentioned prior art, the object is to provide a method and a device for joining joining partners using the principle of laser welding, which enable a flexible joining of joining partners to form complex components in a simple and advantageous manner.

[0007] This object is achieved by a method for joining joining partners to form a component by means of laser welding according to claim 1 and by a device according to claim 17. Advantageous embodiments and expedient further developments of the invention can be found in the subclaims.

[0008] The method for joining joining partners to form a component by means of laser or plastic welding comprises the steps described in detail below and preferably carried out in the order mentioned.

[0009] First, a first component holder is loaded with a first joining partner, in particular in a starting position of the first component holder, and the first joining partner is held by the first component holder or fixed in this first component holder. Next, a second component holder is loaded with a second joining partner, in particular in a starting position of the second component holder, and the second joining partner is held by the second component holder or fixed in this second component holder. The joining partners are preferably made of (reversible or thermoplastically deformable) plastic, in particular made of a thermoplastic, which can be brought to a temperature greater than or equal to the melting temperature of the plastic and at least partially melted by absorbing laser energy or laser radiation.The joining partners inserted into the component holders can be made of the same plastic or different plastics, or even contain different additives, such as dyes, soot particles, glass fibers, carbon fibers, etc. Furthermore, the individual joining partners can have identical or different geometries. Holding the joining partners by the component holders or fixing them in the component holders can be achieved, for example, by clamping the joining partners with a clamping device. However, holding or fixing is also possible using a suction device or a magnetic holding unit or other fixing device.

[0010] Furthermore, the joining surfaces of the joining partners held by the component holders are heated by an irradiation unit having at least one (laser) beam source. The irradiation unit is designed to emit a first and a second radiation. For heating, the first component holder and the second component holder are each arranged in a heating position. In the heating positions, the joining partners arranged in the component holders are positioned relative to the irradiation unit such that the joining surfaces of the joining partners intended for joining can be heated by the irradiation unit. According to the invention, the joining surface of the first joining partner intended for joining can be heated by the first radiation and the joining surface of the second joining partner intended for joining can be heated by the second radiation.The (laser) radiation emitted by the at least one laser beam source preferably strikes the respective joining surface essentially perpendicularly. The arrangement of the component holders in the heating position can be achieved by moving the component holders starting from the respective starting position in which the component holders are equipped with the joining partners. The component holders are designed to be movable for this purpose and can be moved by appropriately controlling an associated drive. In addition to moving the component holders from the respective starting position to the heating position, it is also possible for the starting position of the respective component holder to already be the heating position, so that no movement of the component holder is required to arrange it in the corresponding heating position.In principle, it is also conceivable and encompassed by the invention that the irradiation unit is moved relative to the component holders in order to arrange them in the heating position. The joining surfaces or joining regions of the joining partners provided for joining are in particular joining surfaces that correspond to one another or are essentially identical in shape. The geometric design of the joining surfaces, in particular the depth of the joining surface into the interior of the joining partner, is selected in particular depending on the design of the joining partners or the component to be joined. For the joining of the joining partners, heating to temperatures above the melting temperature of the respective joining partner is carried out. The heating of the two joining partners preferably takes place simultaneously. However, staggered heating is also possible.In particular, depending on the materials of the joining partners, especially the absorption capacity of the joining surfaces, as well as the depth of the joining surface to be heated, the parameters for heating the joining surfaces, such as the respective heating time or the amount of energy introduced, can differ.

[0011] In a further step, in particular immediately after heating the joining surfaces or shortly thereafter, the component holders are arranged with the joining partners arranged therein and heated at the joining surfaces in a joining position, wherein the joining surfaces of the joining partners are arranged opposite one another in the joining position. The arrangement of the component holders in the respective joining position can be achieved by moving the component holders starting from the respective heating position. However, it is also possible that one of the heating positions of the component holders is already the joining position of this component holder, so that no movement of this component holder is required for arrangement in the joining position and only the other component holder is moved from the heating position to the joining position.

[0012] The joining partners are then joined to form a first component. This is done specifically by moving the component holders towards each other and pressing the heated joining surfaces together. The movement of the component holders towards each other can occur by moving one or both component holders in the direction of the other component holder. For example, as described in more detail below, the movement of the component holders towards each other can be force-controlled, i.e. until a predetermined force is reached for bringing the component holders or joining partners together, or position-controlled, i.e. until a predetermined end position of the component holders or a predetermined distance between the joining partners relative to each other is reached. The joining partners are held in the brought together position until the joining surfaces have cooled down sufficiently.In particular, the joining partners are held in this joined position until a specified holding time is reached, specifically until the joining surfaces have a temperature below their respective melting temperature, thus creating a solid bond. Active or controlled cooling is also conceivable to accelerate or control the cooling process. By joining, the two joining partners are firmly and firmly bonded to each other at the joining surfaces.

[0013] The second joining partner is then released from the second component holder and the first component, which consists of the two joined joining partners, is held in the first component holder.

[0014] According to the invention, the method is characterized by repeating the above-mentioned steps at least once, beginning with loading the second component holder with a further joining partner, wherein this further joining partner is joined to form a second component with the first component remaining in the first component holder. The first component to be joined to form the second component with the further joining partner is also referred to as the "joining partner" in the following, in particular to simplify the description, at appropriate points. The heating positions as well as the joining positions of the component holders and the position in which the loading of the second component holder takes place can differ in the further or repeated process run from the positions of the previous run.Furthermore, the joining process, specifically the movement of the component holders toward each other and the dwell time in the pressed-together position until the joining surfaces cool down, can be designed differently from the previous joining process or individually adapted to the new joining partners. For example, a different control can be provided for the movement of the component holders toward each other, in particular also a different movement control of the component holders, specifically an adapted force- or position-dependent control as well as adapted target values, or a different holding time until cooling down. Furthermore, the material of the additional joining partner can be different from that of the first or second joining partner, or even identical to it. The same applies to the geometry of the additional joining partner.By repeating the above-mentioned process steps, which are in particular individually adapted to the two joining partners to be joined to form the second component, a flexible joining to form a final, complex component composed of several joining partners is possible in a fast, simple and process-technically advantageous manner.

[0015] In an advantageous embodiment of the method, the first component holder and / or the second component holder are loaded and / or the joining partners are preferably also fixed in these in a starting position of the respective component holder. The starting position is specifically a position in which the respective component holder has the freest possible access and can therefore be easily loaded with a joining partner. In a preferred embodiment, this is a fixed starting position or one that remains the same for each repetition of the method. However, an adapted selection of the starting position is also possible, in particular depending on the joining partner to be introduced. For example, in the case of very large joining partners, a starting position with improved access to the component holder can be selected.The first and / or the second component holder can be moved into the respective starting position, in particular after the method step of releasing the preceding joining partner from the second component holder, preferably immediately after this method step. This allows the method according to the invention to be continued immediately, in particular by loading the second component holder with the further joining partner. Since the first component remains in the first component holder for joining with the further joining partner and the first component holder is not loaded with a new joining partner, the first component holder can, in an advantageous embodiment, also be moved into the new heating position immediately after the method step of joining to form the first component or releasing the second joining partner from the second component holder.This avoids, in particular, unnecessary movement of the first component holder into its initial position.

[0016] As already mentioned, the heating position of the first and / or second component holder can basically correspond to the starting position of the respective component holder. In a particularly preferred embodiment, however, the starting position and the heating position of one or both component holders can differ from one another, so that the first component holder and / or the second component holder can move from the starting position to the heating position if necessary. This ensures, in particular, advantageous positioning of the component holder for the respective method step, specifically such that in the starting position there is free access to the respective component holder and, in particular, access that is not impaired by the irradiation unit, and in the heating position there is an optimal position of the joining partner relative to the irradiation unit for heating.

[0017] In an advantageous embodiment, the joining surfaces in the heating position each have a fixed predetermined position relative to the irradiation unit, in particular a predetermined distance and / or a predetermined orientation to the latter.

[0018] According to the invention, the heating position of the first component holder is selected depending on the previously joined component arranged in the first component holder and / or depending on the shape of the component to be joined, wherein the new heating position of the first component holder differs from the previous heating position of the first component holder. Preferably, the heating position of the second component holder can also be selected depending on the joining partner arranged in the second component holder or previously joined component. Alternatively or additionally, the heating position of the second component holder can be selected depending on the shape of the component to be joined. In addition to the distance of the component holder from the irradiation unit, a suitable orientation of the component holder to the irradiation unit can therefore be selected for each run of the method.The orientation of the component holder relative to the irradiation unit depends in particular on the arrangement of the joining partner in the component holder and the position of the joining surface to which the joining partner arranged in the other component holder is to be attached. For example, it is conceivable that the further joining partner arranged in the second component holder is attached to the first component remaining in the first component holder at its upper side facing away from the first component holder or at one of the side surfaces of the component. Accordingly, the first component holder, which is designed to be movable for this purpose, must be moved into the appropriate heating position in which the intended joining surface can be heated. The movement of the component holders into the heating position can be a translational movement, a rotational or tilting movement, or a combination of these.The heating position of the first and / or second component holder selected individually for each process run can therefore differ from the previous heating position of the first and / or second component holder. The position of the component holders is preferably detected by a detection unit, for example by a camera system, wherein a correction is made if necessary depending on the detected position of the component holders in order to achieve the desired positioning in the heating position. In a further preferred embodiment, the movement of the first and / or second component holder from the respective heating position to the joining position can be fixed and specifically independent of the individually selected heating position of the component holders. This achieves a targeted and precise arrangement of the component holders in the respective joining position.

[0019] In accordance with the individual selection of the respective heating position, and in particular also in addition thereto, in an advantageous embodiment the joining position of the first and / or second component holder is also individually selected depending on the joining partner or component arranged in the first and / or second component holder and / or depending on the shape of the component to be joined. In particular, the new joining position of the first and / or second component holder differs from the previous joining position of the first and / or second component holder. It is also conceivable for one of the two component holders to have a fixed joining position and for only the joining position of the other component holder to be individually selected and adapted to the component to be joined. Preferably, the correct positioning of the component holders is also detected by a detection unit, wherein, depending on the detected position of the component holders,a correction is made to achieve the desired positioning of the component holder.

[0020] In a particularly advantageous embodiment, the first component holder is removed relative to the irradiation unit when the first component holder is moved from the heating position to the joining position, in particular by a relative movement of the first component holder substantially parallel to an irradiation direction of the irradiation unit, along which the irradiation of the joining partner arranged in the first component holder takes place. The term "substantially parallel," also used below, is to be understood in particular to mean that the aforementioned directions enclose an angle of less than or equal to 30°, preferably less than or equal to 20°, particularly preferably less than or equal to 10°.Furthermore, in a preferred embodiment, the second component holder pivots when moving the second component holder from the heating position to the joining position, in particular pivoting the second component holder about a pivot axis running perpendicular to the irradiation direction of the irradiation unit. Preferably, pivoting by more than 90° is provided, particularly preferably pivoting in the range from 120° to 180°, and most particularly preferably pivoting by approximately 180°. The aforementioned embodiments provide for an advantageous and, in particular, targeted movement of the component holders from the heating position to the respective joining position.

[0021] In a further advantageous embodiment, the irradiation unit is designed such that it can emit (laser) radiation with at least two different wavelengths. In particular, the irradiation unit can have two or more laser beam sources that emit radiation with different wavelengths. These can, in particular, be radiation sources that emit radiation with a wavelength in the near-infrared range (NIR) or in the short-wave infrared light range (780 nm to 3000 nm), in the mid-infrared light range (3000 nm to 8000 nm), or in the long-wave infrared light range (8000 nm to 15000 nm). For cost and performance reasons, laser beam sources with wavelengths in the range from 800 nm to 1070 nm are particularly preferred.In a preferred embodiment, the radiation used to heat a joining partner is selected depending on the respective joining partner, in particular depending on the detected or previously known material or absorption behavior of the respective joining partner. In this case, it is also possible, in particular, for the two joining partners to be joined to be heated using radiation with different wavelengths. This makes it possible to heat the joining surface in a way that is adapted to the respective joining partner. Furthermore, the irradiation unit can also have a corresponding optical device for aligning and focusing the radiation, in particular a controllable mirror arrangement. In a preferred embodiment of the method, the focus diameter of the radiation is adapted depending on a joining partner to be heated or the two joining partners to be heated or the respective joining surfaces to be heated.

[0022] In an advantageous embodiment of the method, the temperature of the joining surfaces of at least one or both joining partners is recorded during heating. In particular, the recording takes place until a temperature value specified for the respective joining partner is reached, specifically a temperature value above the melting temperature of the joining partner. By recording the temperature, a controlled heating of the joining partner is possible. Depending on the recorded temperature, the heating can be adjusted by the irradiation unit if necessary in order to achieve a desired or specified heating level.

[0023] In a further advantageous embodiment, the joining partner(s) is / are heated within a predetermined heating or irradiation time, for example a heating time of a few seconds, in particular less than 60 seconds, particularly preferably less than 40 seconds. Additionally or alternatively, heating can be carried out until smoke development at the joining surface is detected, or heating can be carried out until a predetermined change in the reflective properties of the joining surface occurring as a result of the heating is detected. The smoke development or the reflective properties of the joining surface can be detected by an appropriate optical detection unit. The aforementioned embodiments of the method make it easy to achieve the desired heating of the joining surface.

[0024] Preferably, the joining partners are joined to form a component by a position-controlled movement of the component holders along a predetermined movement path or a movement path with a predetermined distance towards one another. The movement of the component holders can be controlled and detected in particular by controlling corresponding movement drives of the component holders, for example a servo motor. In addition or alternatively, however, it is also possible to detect the movement using an optical detection device, for example a camera, and to control the movement of the component holder depending on the movement detected thereby. Alternatively, the joining of the joining partners can also be force-controlled, namely in such a way that the joining partners are pressed against one another until a predetermined force or a predetermined resistance is reached when the component holders move towards one another.The component holders can be equipped with a corresponding force sensor for this purpose. Alternatively or additionally, a corresponding control system can be implemented, taking into account the power loss of the drives when moving the component holder. These configurations allow the connection of the joining partners, in particular the penetration depth of the joining partners at the molten joining surfaces, to be controlled and adjusted as required.

[0025] In a preferred embodiment of the method, at least one dimension of the joining partners joined to form a component is recorded. Alternatively or additionally, the joining point of the joining partners joined to form a component can be recorded. Likewise, the movement path of the component holders during assembly to form a component can be recorded. The aforementioned recordings can be carried out by an appropriate detection device, for example a camera system or a motion sensor coupled to the component holder, etc. The implementation of the subsequent method steps, in particular the subsequent pass of the method for joining the further component, then takes place specifically depending on the recorded parameters. This can be used to correct any deviations from a predetermined target value of the component.Specifically, this can be achieved by adjusting the heating of the joining surfaces of the subsequently joined components or by adjusting the control of the movement of the component holders during the joining of the subsequently joined components. For example, in the case of a component consisting of several components to be joined to form a stack or one on top of the other, height deviations of a preceding intermediate component from a target value can be compensated. By increasing the melting depth of the components and adjusting the position- or force-dependent control of the movement of the component holders during the joining process, a greater penetration depth can be achieved, for example, which can compensate for exceeding a specified height value or at least reduce the deviation.Accordingly, if a dimension target value is undershot, the penetration depth can be reduced during merging, for example by moving the component holders only up to a specified distance from each other.

[0026] In an advantageous embodiment of the method, the first joining partner is released from the first component holder only after all joining partners have been joined to form a finished or final component, i.e., without an interim and time-consuming release of the first joining partner from the first component holder. The removal of the final component particularly preferably takes place after the first component holder has been moved to a starting position of the first component holder, in which free access is provided and thus easy removal of the finished component is possible.

[0027] The invention further comprises a corresponding device for joining joining partners to form a component by means of laser welding. The device comprises a first component holder and a second component holder for receiving and holding one of the joining partners each. The component holders are movable, in particular translationally movable, rotatable, or pivotable, and are designed to be controllable for a desired movement. In particular, the component holders have correspondingly controllable drives. The device further comprises an irradiation unit with at least one laser beam source for emitting (laser) radiation along at least one irradiation direction for heating joining surfaces of joining partners arranged in the component holders.The irradiation unit is configured to emit a first radiation for irradiating a joining partner arranged in the first component holder and a second radiation for irradiating a second joining partner arranged in the second component holder. According to the invention, the device is characterized in that it comprises a control device configured to carry out the above-mentioned method. Specifically, the device can also comprise one of the configurations described above.

[0028] Preferably, the joining partners are heated in such a way that, in the heating positions of the component holders, the joining surfaces to be heated are aligned substantially perpendicular to the at least one irradiation direction. In a particularly preferred embodiment of the irradiation unit, it is designed to emit the first radiation along a first irradiation direction for irradiating the joining surface of a joining partner arranged in the first component holder and to emit the second radiation along a second irradiation direction for irradiating the joining surface of a joining partner arranged in the second component holder. Alternatively or additionally, the irradiation unit can be designed to emit (laser) radiation with at least two different wavelengths. In particular, the irradiation unit can have at least two laser beam sources that emit (laser) radiation with different wavelengths.In a further preferred embodiment, the irradiation unit is capable of adjusting the focus diameter of the radiation used to heat the joining surfaces. These embodiments enable targeted irradiation suitable for the respective joining surfaces to achieve the desired heating.

[0029] In an advantageous embodiment, the first component holder and / or the second component holder are displaceable substantially parallel and / or perpendicular to the one irradiation direction or an irradiation direction associated with the respective component holder of an irradiation unit that emits radiation along two irradiation directions. Additionally or alternatively, the first and / or the second component holder can be rotated about a rotation axis running parallel to the one or the associated irradiation direction or pivoted about a tilt or pivot axis running perpendicular to the one or the associated irradiation direction. The aforementioned embodiments provide a high degree of mobility of the component holders, which provides a high degree of flexibility for arranging the component holders in the starting, heating, and joining positions, or for moving them into these positions, and allows complex components to be joined.In a particularly advantageous design, the first component holder is displaceable at least substantially parallel to one or the associated irradiation direction and the second component holder is pivotable about a pivot axis running perpendicular to one or the associated irradiation direction, in particular about an angle greater than 90°, preferably about an angle greater than 120° or 150°, particularly preferably about an angle of approximately 180°.

[0030] Preferably, the component holders have a fixing unit for fixing a joining partner therein. In particular, the fixing unit can be configured as a clamping unit, a magnetic fixing unit, a suction unit, or another device that ensures secure and precisely positioned holding of the joining partners in the component holder.

[0031] Furthermore, in an advantageous embodiment, the device has at least one detection unit, for example a camera system, via which properties and changes of at least one, preferably both, joining surfaces, for example their temperature or reflection properties or smoke development at them, can be recorded. In addition or alternatively, the detection unit can record at least one dimension of the joining partners joined to form a component or the current position or movement of the component holders, in particular the movement of the component holders during assembly to form a component. The detection unit provides controlled and targeted control of the joining processes and, in particular, the possibility of adapting the control of the device in the subsequent process steps depending on the recorded parameters.

[0032] These and other features, advantages, and effects of the method according to the invention and the device according to the invention for joining parts to form a component by means of laser welding will become apparent from the following exemplary embodiments described in more detail with reference to the accompanying drawings. The drawings show: Fig. 1 to Fig. 6 a flow diagram of an exemplary joining of two joining partners to form a first component; Fig. 7 to Fig. 13 a flow diagram of an exemplary joining of a further, third joining partner and the Fig. 1 to Fig. 5 produced first component to a second component; Fig. 14 to Fig. 17A Flow diagrams of exemplary joining of a further, fourth joining partner and the Fig. 6 to Fig. 14 generated second component to a third component.

[0033] In Fig. 1 to Fig. Figure 6 shows an example of the process of a first joining of two joining partners 6, 7. The device, which is shown in a highly simplified manner in the figures, has a first component holder 1 with a first fixing unit 2 and a second component holder 3 with a second fixing unit 4. The fixing units 2, 4, shown here as clamping devices, can be used to releasably hold the joining partners 6, 7 in the respective component holder 1, 3. The device further comprises an irradiation unit 5 with at least one laser beam source for emitting laser radiation. The irradiation unit 5, shown in a simplified manner, can in particular also have a plurality of laser beam sources and an optical device for aligning and focusing the emitted laser radiation, such as a controllable mirror arrangement.For the sake of simplicity, it is assumed that the irradiation unit 5 has a central irradiation direction R, with the laser radiation being emitted by the irradiation unit 5 at least substantially in the irradiation direction R. However, other configurations are also possible. For example, the irradiation unit 5 can be configured to emit radiation along a first and a different second irradiation direction.

[0034] Fig. 1 shows the loading of the component holders 1, 3 with one joining partner 6, 7 each. Specifically, the first component holder 1 is already loaded with a first joining partner 6 fixed by the first fixing unit 2 and a second joining partner 7 is inserted into the second component holder 3 and, as in Fig. 2, is held by the second fixing unit 4. The component holders 1, 3 are located for the Fig. 1, each assembly is shown in a starting position, which, in particular, provides easy access to the component holders 1, 3. The joining partners 6, 7 are specifically made of a (reversibly or thermoplastically deformable) plastic, in particular a thermoplastic. The joining partners 6, 7 can, but do not necessarily have to, be made of the same materials. Furthermore, the joining partners 6, 7 can have the same or different geometries.

[0035] Fig. 2 shows the heating of the joining partners 6, 7 by the irradiation unit 5. Specifically, the joining surfaces of the joining partners 6, 7 intended for joining are heated by laser radiation from the irradiation unit 5 to a temperature above the melting point of the respective joining partner 6, 7. The laser radiation preferably strikes the joining surfaces at least substantially perpendicularly. This can be achieved, for example, by an irradiation unit 5 with more than one laser beam source or by an optical device for aligning the radiation. The heating intended for the individual joining partners 6, 7, specifically the laser radiation used, the irradiation duration, the irradiation intensity / power, or the intended final temperature, can be individually selected depending on the joining partner 6, 7 or the joining surface to be heated. For heating, the component holders 1, 3 are arranged in a heating position.In the present embodiment, the joining surfaces are at a predetermined distance from the irradiation unit. The heating position can, as in the present case, already be the starting position. Depending on the configuration of the joining partners 6, 7, however, it is also possible to move one or both component holders 1, 3 parallel to the irradiation direction R in order to maintain the predetermined distance of the joining surface from the irradiation unit 5. Instead of moving the component holders 1, 3, it is also conceivable in principle to move the irradiation unit 5 relative to the component holders 1, 3.

[0036] After heating, the component holders 1, 3 are inserted into the Fig. 3. Specifically, in the present embodiment, the first component holder 1 is moved downwards parallel to the irradiation direction R and the second component holder 3 is pivoted by approximately 180° about a pivot axis S running perpendicular to the irradiation direction R. As shown in Fig. 3, the heated joining surfaces intended for joining are arranged opposite one another in the joining position. In addition to the movement of the component holders 1, 3 into the joining position shown as an example, numerous other movement sequences or corresponding configurations of the component holders 1, 3 are also conceivable. For example, a rotation of the component holder 3 by 180° about a rotation or pivot axis running through its center is possible, together with a translational movement of the second component holder 3 parallel to the x-axis to the left.

[0037] To join the joining partners 6, 7 to a first component 8, the component holders 1, 3 are used as shown in Fig. 4, as shown, towards one another, whereby the heated joining surfaces are pressed together. Specifically, in the present exemplary embodiment, the first component holder 1 is moved upwards parallel to the irradiation direction R or along the z-axis. Alternatively or additionally, a movement of the second component holder 3 downwards parallel to the irradiation direction R is also conceivable. The movement of the first component holder 1 can take place either in a force-dependent manner, i.e. until a predetermined force or resistance value detected by a sensor is reached or until a corresponding power decrease in a drive used to move the component holders 1 is achieved. Alternatively, with knowledge of the dimensions of the joining partners 6, 7, a position-dependent movement of the first component holder 1 along a predetermined movement path upwards is also possible.In order to firmly connect the joining partners 6, 7 to the first component 8, the component holders 1, 3 are held in the position shown in . Fig. 4 until a predetermined or sufficient cooling of the joining surfaces or the joining zone has taken place and the joining partners 6, 7 are firmly connected to the first component 8.

[0038] After joining the joining partners 6, 7 to the first component 8, the second joining partner 7 is, as in Fig. 5, by opening the second fixing unit 4 from the second component holder 3, so that the first component 8 is only held by the first fixing unit 2 in the first component holder 1. Subsequently, as in Fig. 6, a movement of the component holders 1, 3 back into the Fig. 1. Specifically, in this case, the first component holder 1, together with the first component 8 held therein, is moved upwards parallel to the irradiation direction R, and the second component holder 3 is pivoted back by 180° about the pivot axis S.

[0039] Fig. 7 to Fig. 13 show, by way of example, the joining of the first component 8 remaining in the first component holder 1 with a further, third joining partner 9, wherein the third joining partner 9 is attached above the second joining partner 7 in the present exemplary embodiment. The geometry and material of the third joining partner 9 can, in principle, be the same as or different from those of the first two joining partners 6, 7. The above statements regarding the joining process of the first component 8 apply accordingly, so that the differences from the first joining process are essentially discussed here.

[0040] As in Fig. 7 and Fig. 8, the third joining partner 9 is inserted into the second component holder 3 and fixed therein by the second fixing unit 4. At the same time, or possibly subsequently, the first component holder 1 is moved downwards parallel to the irradiation direction R into the new heating position, in which the intended joining surface of the first component 8 has a predetermined distance from the irradiation unit 5. As the comparison of Fig. 2 and Fig. 8 shows, the new heating position of the first component holder 1 differs from the previous heating position of the first component holder 1 due to the greater height of the first component 8 compared to the first joining partner 6. In addition to the sketched movement sequence, in which the first component holder 1 is moved into the position shown in Fig. 7 shown starting position, it is also possible that the first component holder 1 is moved directly from the Fig. 5 shown position into the Fig. 8 or Fig. 9. A movement of the second component holder 3 from the starting position to the heating position shown in Fig. The heating position shown in Figure 8 is not required in this case. However, depending on the design of the third joining partner 9, the second component holder 3 can also be moved from the starting position to the heating position.

[0041] Following the Fig. 8 shown moving the component holders 1, 3 into the heating position and the Fig. 9 shown heating of the joining surfaces takes place in Fig. 10 and Fig. 11 shows the joining of the first component 8 and the third joining partner 9. In this case, deviations of the first component 8 from a predetermined target value, which are detected by a detection device (not shown), can be taken into account. In the present case, the predetermined target value can be, in particular, the height of the first component 8 in the z-direction, whereby deviations from this target value can arise as a result of the joining of the first two joining partners 6, 7 to form the first component 8. To compensate for a detected excessive height of the first component 8, for example, the joining surfaces can be heated deeper into the first component 8 and / or the third joining partner 9 and the first component 8 and the third joining partner 9 can be pressed together during joining in such a way that a greater sinking of the joining surfaces is achieved.Accordingly, if the height of the first component 8 is too low, the control can be adjusted to a lesser degree of heating and a lesser sinking of the joining surfaces. Of course, other deviations from a specified target value, for example, detected deviations of the third joining partner 9 to be joined, can also be taken into account during heating and joining to form the second component 10.

[0042] Fig. 12 and Fig. 13 show the subsequent release of the third joining partner 9 from the second component holder 3 and the movement of the component holders 1, 3 with the second component 10 remaining in the first component holder 1 into their starting positions.

[0043] If the second component 10 is already the final component to be manufactured, it can then be released and removed from the first component holder 1. However, it is also possible, as starting with the assembly in Fig. 14, the second component 10 and a further, fourth joining partner 11 are joined together to form a third component 12.

[0044] In Fig. 15 to Fig. Figure 17A shows three examples of joining the second component 10 and the fourth joining partner 11 to form a third component 12. Specifically, the figures show the arrangement of the component holders 1, 3 in the heating positions and the resulting third component 12.

[0045] In Fig. 15, the fourth joining partner 11 is placed above the third joining partner 10 on the second component 10 to the Fig. 15A shown third component 12. As the comparison of Fig. 15 with Fig. 2 and Fig. 8 shows, the new heating position differs from the previous heating positions of the first component holder 1 due to the greater height of the second component 10 compared to the first joining partner 6 or the first component 8.

[0046] In the Fig. 16, the fourth joining partner 11 is also joined above the third joining partner 10 to the second component 10, but in comparison to the example from Fig. 15 to the right. As in Fig. As shown in Figure 16, the first component holder 1 is moved downwards and parallel to the x-direction to the left into the heating position. The resulting third component 12 is in Fig. 16A shown

[0047] In Fig. 17 is an example of the joining of the fourth joining partner 11 laterally to the second component 10 to the Fig. 17A. For simplification, the first component holder 1 is designed in such a way that it can also be tilted about a tilt axis K that can be tilted perpendicular to the irradiation direction R into the Fig. 17, the heating position shown can be tilted. However, other designs are also conceivable. Reference symbol 1 First component recording 2 First fixation unit 3 Second component recording 4 Second fixation unit 5 Irradiation unit 6 First joining partner 7 Second joining partner 8 First component 9 Third joining partner 10 Second component 11 Fourth joining partner 12 Third component R Irradiation direction S swivel axis K Tilt axis

Claims

[1] Method for joining joining partners to form a component (8, 10, 12) by means of laser welding, comprising the following steps (a) equipping a first component holder (1) with a first joining partner (6) and holding the first joining partner (6) by the latter; (b) equipping a second component holder (3) with a second joining partner (7) and holding the second joining partner (7) by the latter; (c) heating the joining surfaces of the joining partners (6, 7) arranged in the component receptacles (1, 3) by means of an irradiation unit (5) having at least one laser beam source and designed to emit a first radiation and a second radiation, wherein the first component receptacle (1) and the second component receptacle (3) are each arranged in a heating position in which the joining partners (6, 7) are arranged relative to the irradiation unit (5) in such a way that the joining surface of the first joining partner (6) intended for joining can be heated by the first radiation and the joining surface of the second joining partner (7) intended for joining can be heated by the second radiation; (d) arranging the component holders (1, 3) with the joining partners (6, 7) held thereby in a joining position in which the joining surfaces of the joining partners (6, 7) are arranged opposite one another; (e) joining the joining partners (6, 7) to form a first component (8), in particular comprising a step of moving the component holders (1, 3) towards one another; (f) releasing the second joining partner (7) from the second component holder (3) and holding the first component (8) in the first component holder (1); characterized by repeating steps (b) to (f) at least once, wherein the second component holder (3) is equipped with a further joining partner (9) and is joined to a second component (10) with the first component (8) remaining in the first component holder (1), and wherein the heating position of the first component holder (1) is selected as a function of the component (8, 10, 12) arranged in the first component holder (1) and / or as a function of the shape of the component (8, 10, 12) to be joined, wherein the new heating position of the first component holder (1) differs from the preceding heating position of the first component holder (1). [2] Method according to claim 1, characterized by that the loading of the first component holder (1) and / or the loading of the second component holder (3) each takes place in a starting position, and in particular after step (f) the first component holder (1) and / or the second component holder (3) is moved into the respective starting position. [3] Method according to claim 2, characterized by a movement of the first component holder (1) and / or the second component holder (3) from the starting position into the heating position. [4] Method according to one of the preceding claims, characterized by that the first component holder (1) is moved directly into the new heating position after being joined to the component (8), in particular without moving into a starting position of the first component holder (1). [5] Method according to one of the preceding claims, characterized bythat the joining surfaces in the heating position each have a fixed predetermined position relative to the irradiation unit (5), in particular a predetermined distance and / or a predetermined alignment thereto. [6] Method according to one of the preceding claims, characterized by that the heating position of the second component holder (1, 3) is selected depending on the joining partner arranged in the second component holder (1, 3) and / or depending on the shape of the component (8, 10, 12) to be joined, wherein in particular the new heating position of the second component holder (1, 3) differs from the preceding heating position of the second component holder (1, 3). [7] Method according to one of the preceding claims, characterized by a fixed movement of the first component holder (1, 3) from the heating position to the joining position, which is independent of the individual heating position. [8] Method according to one of the preceding claims, characterized by that the joining position of the first and / or second component holder (1, 3) is selected as a function of the joining partner or component (8, 10, 12) arranged in the first and / or second component holder (1, 3) and / or as a function of the shape of the component (8, 10, 12) to be joined, in particular that the new joining position of the first and / or second component holder (1, 3) differs from the preceding joining position of the first and / or second component holder (1, 3). [9] Method according to one of the preceding claims, characterized bya removal of the first component holder (1) from the irradiation unit (5) when the first component holder (1) is moved from the heating position into the joining position, in particular by a relative movement of the first component holder (1) substantially parallel to an irradiation direction (R) of the irradiation unit (5), and / or a pivoting of the second component holder (3) when the second component holder (3) is moved from the heating position into the joining position, in particular a pivoting of the second component holder (3) about a pivot axis (S) running perpendicular to an irradiation direction (R) of the irradiation unit (5), particularly preferably a pivoting by more than 90°, particularly preferably a pivoting in the range from 120° to 180°. [10] Method according to one of the preceding claims, characterized bythat the irradiation unit (5) can emit radiation with at least two different wavelengths, in particular has two laser beam sources which emit radiation with different wavelengths, and a selection of the radiation used for the respective heating of a joining partner (6, 7, 8, 9, 10, 11) takes place depending on the respective joining partner (6, 7, 8, 9, 10, 11), in particular depending on the detected and / or previously known material and / or absorption behavior of the respective joining partner (6, 7, 8, 9, 10, 11). [11] Method according to one of the preceding claims, characterized by an adjustment of the focus diameter of the radiation depending on one or both joining partners to be heated (6, 7, 8, 9, 10, 11). [12] Method according to one of the preceding claims, characterized bydetecting the temperature of the joining surfaces of at least one, preferably both, joining partners (6, 7, 8, 9, 10, 11) during heating, in particular until a temperature value predetermined for the respective joining partner (6, 7, 8, 9, 10, 11) is reached. [13] Method according to one of the preceding claims, characterized by a predetermined heating time within which heating of the joining partner(s) (6, 7, 8, 9, 10, 11) takes place and / or heating until smoke development is detected at the joining surface and / or heating until a predetermined change in the reflection properties of the joining surface is detected. [14] Method according to one of the preceding claims, characterized bythat the joining of the joining partners (6, 7, 8, 9, 10, 11) to form a component (8, 10, 12) is carried out in a position-controlled manner by a predetermined movement of the component holders (1, 3) towards one another and / or in a force-controlled manner, in particular until a predetermined force or a predetermined resistance is reached when the component holders (1, 3) are moved towards one another. [15] Method according to one of the preceding claims, characterized by detecting at least one dimension of the joining partners (6, 7, 8, 9, 10, 11) joined to form a component (8, 10, 12) and / or detecting the joining point of the joining partners (6, 7, 8, 9, 10, 11) joined to form a component (8, 10, 12) and / or detecting the movement path of the component holders (1, 3) when joining to form a component (8, 10, 12), as well as carrying out the subsequent method steps depending on the detected parameters in order to compensate for a deviation from a predetermined target value, wherein in particular an adapted heating of the joining surfaces of the joining partners (6, 7, 8, 9, 10, 11) to be joined subsequently and / or an adapted control of the movement of the component holders (1, 3) during Joining together the joining partners (6, 7, 8, 9, 10, 11) to be joined subsequently takes place. [16] Method according to one of the preceding claims, characterized by a release of the first joining partner (6) from the first component holder (1) after the joining of all joining partners (6, 7, 8, 9, 10, 11) to form a finished component (10, 12), in particular without an intermediate release of the first joining partner (6) from the first component holder (1), and a removal of the finished component (10, 12) from the first component holder (1), particularly preferably from the first component holder (1) arranged in a starting position. [17] Device for joining joining partners to form a component (8, 10, 12) by means of laser welding, comprising a movably mounted first component holder (1) and a movably mounted second component holder (3) for receiving and holding a joining partner and an irradiation unit (5) for heating joining surfaces of joining partners arranged in the component holders (1, 3) with at least one laser beam source for emitting radiation along at least one irradiation direction (R), wherein the irradiation unit (5) is designed to emit a first radiation for irradiating a first joining partner arranged in the first component holder (1) and a second radiation for irradiating a second joining partner arranged in the second component holder (3), characterized by that the device has a control device configured to carry out the method according to one of claims 1 to 16. [18] Device according to claim 17, characterized by that the irradiation unit (5) is designed to emit the first radiation along a first irradiation direction for irradiating the joining surface of the joining partner arranged in the first component holder (1) and to emit the second radiation along a second irradiation direction for irradiating the joining surface of the joining partner arranged in the second component holder (3) and / or that the irradiation unit (5) is designed to emit radiation with at least two different wavelengths, in particular has two laser beam sources which emit radiation with different wavelengths and / or that the irradiation unit (5) is designed to adapt the focus diameter of the radiation used for heating the joining surfaces. [19] Device according to claim 17 or 18, characterized bythat the first and / or the second component holder (1, 3) are displaceable substantially parallel and / or perpendicular to the one or the associated irradiation direction (R). [20] Device according to one of claims 17 to 19, characterized bythat the first and / or the second component holder (1, 3) is rotatable about a rotation axis running parallel to the one or the associated irradiation direction (R) and / or that the first and / or the second component holder (1, 3) is pivotable about a tilt axis (K) or pivot axis (S) running perpendicular to the one or the associated irradiation direction (R), in particular that the first component holder (1) is displaceable at least substantially parallel to the one or the associated irradiation direction (R) and the second component holder (3) is pivotable about a pivot axis (S) running perpendicular to the one or the associated irradiation direction (R), in particular about an angle greater than 90°. [21] Device according to one of claims 17 to 20, characterized by that the first component holder (1) and / or the second component holder (3) has a fixing unit (2, 4) for fixing the joining partner in it. [22] Device according to one of claims 17 to 21, characterized by at least one detection unit for detecting a change in the joining surfaces, in particular for detecting the temperature of at least one joining surface and / or for detecting the reflection properties of at least one joining surface and / or for detecting smoke development on at least one joining surface, and / or a detection unit for detecting at least one dimension of the joined components (8, 10, 12) and / or the joining partners (6, 7, 8, 9, 10, 11) to be joined to form a component (8, 10, 12).

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