Rectifier for a welding transformer of a welding device and method for manufacturing such a rectifier

Abstract

Rectifiers (40; 40A, 400) for a welding transformer (30) of a welding device (2; 3) for welding at least one component (5, 6) and a method for manufacturing such a rectifier (40; 40A, 400). The rectifier (40; 40A, 400) includes a first side member (47), a second side member (48), an intermediate member (49) disposed between the first and second side members (47, 48), and at least two semiconductor modules (401), the semiconductor modules being connected between an output of a welding tool (10) of the welding device (2; 3) and an output of the welding transformer (30), wherein the first side member (47) and the second side member (48) are designed asymmetrically such that an exchange of the arrangement structure of the side members (47, 48) relative to the intermediate member (49) changes the number of semiconductor modules (401) that can be clamped between one of the side members (47, 48) and the intermediate member (49).

Description

Field of the Invention

[0001] The present invention relates to a rectifier for a welding transformer of a welding device and a method for manufacturing such a rectifier. Background Art

[0002] Welding devices are used, for example, in production facilities, especially in production lines for vehicles and the like, in order to connect metal components by welding with the aid of the welding tools of the welding device. The welding tools are, for example, welding tongs, which are supplied with welding current by a welding transformer. The welding tools are especially resistance welding tools. In addition, welding devices can be used in single-piece production. If necessary, it may be possible to control the welding device at least partly manually.

[0003] The welding transformer can preferably be implemented as an intermediate frequency direct current transformer (MF-DC transformer). For this purpose, a rectifier is mounted on the welding transformer. Such a welding transformer is also referred to as a transformer-rectifier unit.

[0004] Due to the direct current during welding, magnetization of the welded components may occur. Therefore, it becomes difficult to further process the welded metal components. Through the possible magnetization of the facility components, contamination and malfunctions in the welding facility can be caused.

[0005] In addition, through the different alloys for the welded sheets, different combinations of sheet thicknesses, and the Peltier effect in aluminum, undesired burn-off or material migration on the welding electrodes can occur depending on the welding current direction.

[0006] These effects occur especially during the resistance welding of links and during the welding of heating elements.

[0007] In order to avoid these effects, it may be possible to perform polarity switching in the welding transformer. Therefore, different from a conventional diode rectifier, the disturbing magnetization effects formed can be avoided very effectively, simply, and inexpensively.

[0008] Such a transformer-rectifier unit has better operating characteristics compared to a diode rectifier, because a rectifier with four thyristors has higher losses and lower power. In view of the economical use of resources, the poor operating characteristics are not desired. In addition, the poor operating characteristics result in higher costs for the users of resistance welding devices.

[0009] However, depending on the requirements, a transformer-rectifier unit with or without polarity switching is needed. Now, the two variant solutions are very different in terms of the type of construction. This results in higher costs in terms of providing different components for the transformer-rectifier unit. In addition, the employees and / or machines used for installing the transformer-rectifier unit have to learn and prepare expensively for installing different transformer-rectifier units. Summary of the Invention

[0010] Accordingly, the object of the present invention is to provide a rectifier for a welding transformer of a welding device and a method for manufacturing such a rectifier, by means of which the problems mentioned above can be solved. In particular, a rectifier for a welding transformer of a welding device and a method for manufacturing such a rectifier should be provided, wherein the manufacture of the rectifier and thus of the transformer-rectifier unit is simplified and the transformer-rectifier unit is configured with or without polarity switching according to the requirements.

[0011] This object is solved by a rectifier for a welding transformer of a welding device according to claim 1. The rectifier has a first side member, a second side member, an intermediate member arranged between the first and second side members, and at least two semiconductor modules, which are connected between the welding tool of the welding device and the output of the welding transformer, wherein the first side member and the second side member are designed asymmetrically such that an exchange of the arrangement structure of the side members relative to the intermediate member changes the number of semiconductor modules, which can be clamped between one of the side members and the intermediate member.

[0012] The rectifier claimed in the claims is configured such that different variant solutions of the rectifier can be installed very inexpensively and with an almost minimal probability of failure. The components of the rectifier are designed such that two different structural variant solutions of the rectifier can still be achieved with a minimum number of components.

[0013] In addition, the rectifier has a common part for a semiconductor structure group, in particular MOSFETs. The semiconductor structure group has a significant energy saving compared to conventional welding transformers. With the variant solution of pole switching or polarity switching, the user of the transformer-rectifier unit achieves great process advantages.

[0014] The design of the side members and the use of the common part in the rectifier optimize the costs of the two transformer variant solutions with and without pole switching, such that the installation of the rectifier is not as complex as before. Thereby, not only is the provision of the components less costly, but also the training of the employees and / or the setting of the machines used for manufacturing is less complex. Accordingly, the error rate regarding the manufacture of the rectifier also decreases. Thus, the quality of the rectifier is improved and the number of defective products during manufacture is reduced. Overall, the resource requirements can thereby be reduced.

[0015] Furthermore, rectifiers with or without polarity switching are identically constructed in their external shape and size. This results in the fact that devices for moving the welding device in space (such as robots) do not have to be differently taught for different types of transformer-rectifier units and do not have to be switched during operation. This also helps to simplify the commissioning, operation, and maintenance of the welding facility.

[0016] Overall, the rectifier claimed in the claims is constructed such that simple polarity switching of the welding transformer can be achieved with small structural dimensions and low losses as required. However, the rectifier can subsequently also be very inexpensively retrofitted to the corresponding other variants as required.

[0017] Advantageous further design options of the rectifier are specified in the dependent claims.

[0018] In the rectifier, the arrangement of the first side member to the left of the intermediate member and the arrangement of the second side member to the right of the intermediate member provide a space for arranging one of at least two semiconductor modules between the first side member and the intermediate member and a space for arranging one of at least two semiconductor modules between the second side member and the intermediate member, and the arrangement of the first side member to the right of the intermediate member and the arrangement of the second side member to the left of the intermediate member provide a space for arranging two of at least four semiconductor modules between the first side member and the intermediate member in the case of pole switching and a space for arranging two of at least four semiconductor modules between the second side member and the intermediate member in the case of pole switching.

[0019] It is possible that at least two semiconductor modules are designed as universal parts, which are either arranged together between one of the side members and the intermediate member and connected as a series circuit consisting of two transistors between the welding tool and the output of the welding transformer, or are arranged individually between the side member and the intermediate member and connected between the welding tool and the output of the welding transformer.

[0020] It is conceivable here that at least two semiconductor modules each have at least one transistor, where the polarity of one transistor of the series circuit is rotated relative to the polarity of the other transistor of the series circuit in a preset direction in order to achieve a polarity-switchable welding voltage and a polarity-switchable welding current on the welding transformer in the case of the series circuit. Here, the transistor with the rotated polarity can be provided for connection to the welding tool.

[0021] In one design variant, the transistor is a metal-oxide-semiconductor field-effect transistor.

[0022] To this end, the rectifier can also have fastening elements for fastening the lateral parts to the welding transformer, wherein the fastening elements are arranged on the lateral parts, so that the same fastening points can be used on the welding transformer regardless of how the lateral parts are arranged relative to the intermediate part, whereby a polarity-switchable welding current can or cannot be achieved.

[0023] At least one of the previously described rectifiers can be part of a welding device, which furthermore has a welding tool with at least one welding electrode, which contacts at least one component for welding, and the welding device also has at least one welding transformer for delivering current to the welding tool when welding at least one component. Here, at least one rectifier can be connected to at least one welding transformer.

[0024] It is possible that the welding transformer has at least two, but preferably three, output terminals, on two of which there are respectively series circuits consisting of two transistors, the ends of the series circuits being connected to each other and leading to the welding tool together with a possible third output terminal of the welding transformer. Furthermore, it is possible that the series circuit of the transistors also consists only of one or more transistors connected in parallel with the same polarity. Furthermore, it is possible that the series circuit consists only of one transistor for a non-polarity-switching variant. The welding tool may furthermore have a control device for switching on the transistors connected in series in a negatively conductive manner with respect to the current in synchronous operation.

[0025] It is conceivable that the welding tool is a welding pliers with two welding electrodes, between which at least one component is arranged during welding.

[0026] The previously described welding device can be part of a facility that is set up to process an object using the welding device. Here, the welding device can be set up to weld at least one component that is set up to process at least one of the objects. Here, the facility can be designed to manufacture a vehicle body-in-white or a heating body or a chain as the object.

[0027] This task is furthermore solved by a method for a rectifier for a welding transformer of a welding device according to claim 14. The method has the following steps: arranging an intermediate part between a first and a second lateral part, and arranging at least one semiconductor module each between the intermediate part and the first and second lateral parts, wherein the first lateral part and the second lateral part are designed asymmetrically, so that an exchange of the arrangement structure of the lateral parts relative to the intermediate part changes the number of semiconductor modules that can be clamped between one of the lateral parts and the intermediate part, and electrically connecting at least two semiconductor modules between the welding tool and the output terminals of the welding transformer.

[0028] This method achieves the same advantages as those previously mentioned for the rectifier.

[0029] Further possible embodiments of the present invention also include combinations of features or embodiments not specifically mentioned that were described previously or subsequently in connection with the examples. Here, those skilled in the art may also add individual aspects as improvements or supplements to the corresponding basic forms of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be described in detail hereinafter with reference to the drawings and by way of examples. Among them:

[0031] Figure 1 shows a block diagram of a facility having a welding device according to a first embodiment;

[0032] Figure 2 shows a three-dimensional view of a semiconductor module of a rectifier for a welding device according to a first embodiment;

[0033] Figure 3 shows a three-dimensional view of a rectifier for a welding transformer with polarity switching according to a first embodiment;

[0034] Figure 4 and Figure 5 respectively show Figure 3 side views of the rectifier;

[0035] Figure 6 shows a three-dimensional view of a welding transformer without polarity switching for a resistance welding device according to a second embodiment;

[0036] Figure 7 and Figure 8 respectively show Figure 6 side views of the rectifier; and

[0037] Figure 9 shows a block diagram of a facility having a resistance welding device according to a third embodiment.. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] In the drawings, unless otherwise stated, the same or functionally identical elements are provided with the same reference numerals.

[0039] Figure 1 A facility 1 having a welding device 2 is shown very schematically. The welding device is in particular a resistance welding device. The facility 1 is, for example, a manufacturing facility for objects 4, such as vehicles, furniture, heating elements, etc.

[0040] In facility 1, metal components 5, 6 can be connected by welding, in particular by resistance welding, thereby establishing a welded connection 7. For this purpose, the welding device 2 has a welding tool 10 in the form of a welding pliers with two welding electrodes 11, 12, a control device 20, a welding transformer 30 with three output terminals 31, 32, 33, and a rectifier 40, which is composed of a first transistor 41, a second transistor 42, a third transistor 43, and a fourth transistor 44. In Figure 1 the example of

[0041] the welding device 2 furthermore has a device 50 for guiding the welding tool 10.

[0042] The welding device 2 can establish the welded connection 7 using the welding tool 10 under the control of the control device 20.

[0043] Here it is possible, for example, that two edges or margins or corners of a single component 5 are interconnected by resistance welding using one or more welded connections 7. Irrespective of how many components 5, 6 are interconnected by the welded connection 7, the welded connection 7 can be implemented as spot welding or a weld seam or a combination thereof.

[0044] On the secondary side of the welding transformer 30, a first secondary voltage U21 exists between the first and second output terminals 31, 32 of the welding transformer 30. Furthermore, a second secondary voltage U22 exists between the second and third output terminals 32, 33 of the welding transformer 30. The first secondary voltage U21 and the second secondary voltage U22 form a welding voltage U23 after the rectifier unit 40, which causes a welding current I2.

[0045] The first transistor 41 is connected to the first output terminal 31 of the welding transformer 30. The second transistor 42 is connected in series with the first transistor 41. Thereby, the series circuit composed of the first and second transistors 41, 42 is connected between the welding transformer 30 and the welding tool 10. More precisely, the series circuit composed of the first and second transistors 41, 42 is connected between the welding transformer 30 and the first welding electrode 11.

[0046] The second welding electrode 12 is directly connected to the second output terminal 32 of the welding transformer 30.

[0047] A third transistor 43 is connected to the third output terminal 32 of the welding transformer 30. A fourth transistor 44 is connected in series with the third transistor 43. Thus, the series circuit formed by the third and fourth transistors 43, 44 is connected between the welding transformer 30 and the welding tool 10. More precisely, the series circuit formed by the third and fourth transistors 43, 44 is connected between the welding transformer 30 and the first welding electrode 11.

[0048] The control device 20 can also switch the polarity of the welding voltage U23 on the welding electrodes 11 and 12 as desired through the corresponding control transistors 41, 42, 43, 44. The control device 20 is designed to turn on the transistors in the transistors 41, 42, 43, 44 respectively according to the output voltage and polarity preselection. The series-connected transistors of the transistors 41, 42, 43, 44 are then turned on in a negative-conduction manner in synchronous operation in terms of current.

[0049] For example, the control device 20 turns on the first transistor 41 respectively according to the output voltage and polarity preselection. The series-connected second transistor 42 is turned on in a negative-conduction manner in synchronous operation in terms of current. In this case, the welding current I2 is the current flowing out positively from the electrode 11. The electrode 11 is thus positively polarized. The electrode 12 is negatively polarized.

[0050] If the welding current I2 is polarized conversely, then other transistors 42, 44 are used for polarity preselection respectively, and the relevant transistors are switched to negative conduction. The electrode 11 is thus negatively polarized. The electrode 12 is positively polarized.

[0051] Then, thus, in the rectifier 40, in each rectifier branch, two transistors, namely the transistors 41, 42 in this example, are connected in series. The same situation applies in the same way to the series circuit formed by the third and fourth transistors 43, 44 (which is another rectifier branch of the rectifier 40).

[0052] In this way, a polarity-switchable welding voltage U23 and a polarity-switchable welding current I2 between the welding electrodes 11, 12 can be achieved on the welding transformer 30.

[0053] In a welding method for welding at least one component 5, 6 using the welding device 2, especially resistance welding, at least one welding electrode 11, 12 contacts at least one component 5, 6, and at least one welding transformer 30 is used to deliver current to the welding tool 30 when welding at least one component 5, 6. Here, a series circuit composed of two transistors 41, 42; 43, 44 is provided for pole switching, and the transistors are connected between the welding tool 10 and the output terminals 31, 33 of the welding transformer 30, as Figure 1as shown. The following steps are performed in the welding method, namely, two transistors 41, 42 of the same polarity are selected; the polarity of 43, 44, and the method is to preselect and turn on the transistors from the pair 41, 42 or the transistors from the pair 43, 44 according to the output voltage and polarity of the welding transformer 30. In addition, in the synchronous operation, the step of turning on the transistors 41 or 42; 43 or 44 connected in series with the turned-on transistors 41 or 42; 43 or 44 in a negative conduction manner is performed in terms of current. Thus, the polarity of one transistor 42; 44 of the series circuit rotates relative to the polarity of the other transistor 41; 43 of the series circuit, so as to achieve a polarity-switchable welding voltage U23 and a polarity-switchable welding current I2 on the welding transformer 30.

[0054] The transistors with rotating polarities can be arranged for connection to the welding tool 10. More precisely, in the rectifier 40, two series circuit branches are combined together and then led to the welding tool 10.

[0055] The welding device 2 can be used particularly advantageously in sheet combinations, where it causes undesirable burning or material migration of the welding electrodes in the welding pliers. In addition, the resistance welding device 3 can be used particularly advantageously in welding links and in welding heating elements.

[0056] Figure 2 The mechanical structure of the semiconductor module 401 of one of the transistors 41 to 44 for the rectifier 40 is shown simplified. The semiconductor module 401 has a parallel circuit of a plurality of semiconductor components 4015, and the semiconductor components are especially transistors. The semiconductor module 401 has a substrate 4011 and a cover plate 4012, and their corners are respectively left empty. Thus, the semiconductor module 401 approximately has a cross shape. On the sides of the cross, connection tabs or direct connectors 4013 protrude outwards, which are also shown in Figure 3 and can be inserted into the connector 402 of a conductor plate or a drive circuit board 403 not shown in detail according to Figure 2 For this purpose, the semiconductor modules 401 are placed back to back with each other, so that the connection tabs and thus the connectors 402 can be arranged side by side, as can also be deduced from the overview of Figure 3

[0057] The direct connector 4013 is arranged on the substrate 4011. Both the substrate 4011 and the cover plate 4012 are made of a highly conductive material, which is highly thermally conductive and highly electrically conductive. An additional metal layer 4014, especially a copper layer, etc., is applied on the substrate 4011, and the metal layer is insulated from the substrate 4011 by an insulating material. The additional metal layer 4014, especially a copper layer, etc., is applied by a method common in the manufacture of conductor plates. Obviously, other methods can also be considered for the application.

[0058] The semiconductor structural element 4015 is introduced in a sandwich structure between the substrate 4011 and the cover plate 4012 by means of a soldering method and is in contact with the corresponding plates 4011, 4012 and the lines and / or the interfaces for signals. For the sake of clarity, in Figure 3 not all semiconductor structural elements 4015 are provided with reference numerals.

[0059] The module 401 thus accommodates a parallel circuit of transistors or semiconductor elements 4015 between the substrate 4011 and the cover plate 4012. In the intermediate space between the substrate 4011 and the cover plate 4012, a plurality of semiconductor structural elements 4015, for example between 30 and 50, are connected in parallel. The semiconductor structural element 4015 has, for example, a metal-insulator-field-effect transistor (MISFET), in particular a metal-oxide-field-effect transistor (MOSFET), the type of which can be selected according to the application.

[0060] The module 401 is at least partially, in particular entirely, gold-plated in order to improve the conductivity at the interfaces implemented by means of the direct connector 4013 and / or at the interfaces of the parallel circuit of the semiconductor structural elements 4015 on the substrate 4011 and the cover plate 4012.

[0061] In Figure 2 the drive circuit board 403 of can also arrange the control device 20. The semiconductor modules 401 are designed identically. Therefore, the semiconductor module 401 is a universal component.

[0062] Each semiconductor module 401 has at least one field-effect transistor, however, in particular between 30 and 50 according to the type, which is in particular a field-effect transistor, in particular an NMOS-FET. Therefore, the module 401 can also be referred to as an IGFET module. The IGFET module can in particular have at least one metal-oxide-semiconductor-field-effect transistor (metal-oxide-semiconductor field-effect transistor = MOSFET).

[0063] The connector 402 for plugging (which can be designed as a direct plug) is arranged eccentrically on the semiconductor module 401. Thereby, two semiconductor modules 401 can be brought into contact with each other via the conductor plate of the drive circuit board 403 by means of their substrates 4011. The drive circuit board 403 with the driver 404 and the control device 20 are constructed in such a way that two functions of the rectifier 40 with or without pole switching or polarity switching can be realized according to the equipment variant.

[0064] Figure 3More accurately shows the mechanical structure of the rectifier 40 according to the current embodiment on the installation accommodation unit 51 of the device 50. The installation accommodation unit 51 is for welding the output end of the electrode 11. Figure 4 and Figure 5 Shows different side views of the rectifier 40.

[0065] The rectifier 40 has a first pressure plate 45, a second pressure plate 46, an A side member 47, a B side member 48, and an intermediate member 49. Between the A side member 47 and the intermediate member 49, two semiconductor modules 401 are arranged. Between the B side member 48 and the intermediate member 49, two semiconductor modules 401 are also arranged. In Figure 3 only the connection tabs of the semiconductor modules 401 for connecting the connectors 402 can be seen respectively. Therefore, with the rectifier 40, a function with pole switching or polarity switching can be achieved, as described previously with Figure 1 described. In the case of no pole switching, only two modules 401 exist, and this will be described in detail later with reference to Figures 6 to 8 this.

[0066] According to Figures 3 to 5 , the rectifier 40 has a sandwich structure, where the intermediate member 49 is arranged between the A side member 47 and the B side member 48. In addition, the combination composed of the members 47, 49, 48 is arranged between the A side member 47 and the B side member 48. Therefore, the first pressure plate 45, the A side member 47, the intermediate member 49, the B side member 48, and the second pressure plate 46 are arranged in the mentioned order successively or side by side. The mentioned combination 45, 47, 49, 48, 46 is fastened to each other by fastening elements 451. The fastening elements 451 penetrate through the combination 45, 47, 49, 48, 46. This can be seen better in Figure 4 this. In particular, at least one of the fastening elements 451 can be a screw screwed into the invisible thread of the pressure plate 46. Alternatively, at least one of the fastening elements 451 can be a screw screwed into a nut accommodated in the pressure plate 46.

[0067] The side members 47, 48 are implemented as conductive plates, especially copper plates, etc. Obviously, other conductive materials, especially metals, can be used for the side members 47, 48. The side members 47, 48 can also be referred to as transformer - AC voltage - copper plates.

[0068] The intermediate part 49 is made of a conductive material. The intermediate part 49 is conductively fastened, in particular screwed, to the mounting receiving unit 51 and is thus part of the current output terminal in the direction of the welding electrode 11. The side parts 47, 48 (which are made of a conductive material as described above) are insulatingly fastened, in particular screwed, to the mounting plate 51. The pressure plates 45, 46 are made of a conductive material in the present example. The pressure plates 45, 46 are insulated from the adjacent side parts 47, 48 by the insulating discs 450. Alternatively, it is possible that the pressure plates 45, 46 are made of a non-conductive material, so that the insulating discs 450 can be dispensed with. In other words, an insulating disc 450 is arranged between the intermediate part 47 and the pressure plate 45. Even when the insulating disc 450 is not visible in Figure 3 , an insulating disc 450 for non-contact mounting is also provided between the side part 48 and the pressure plate 46.

[0069] The side parts 47, 48 and the intermediate part 49 are fastened to the mounting receiving unit 51 by fastening elements 511 to 513. Here, the side parts 47, 48 (regardless of whether they are placed on the left or right or vice versa relative to the intermediate part 49) are fastened to the mounting receiving unit 51 by an insulating member, in particular implemented as at least one insulating disc. The fastening elements 511 to 513 are Figure 3 screws in the example, which are fastened in the openings of the side parts 47, 48, the intermediate part 49 and the mounting receiving unit 51. Due to the required insulation between the side parts 47, 48 and the mounting receiving unit 51, the fastening elements 511 and 513 require additional insulating discs 450 for the non-contact but fixed mounting of the respective parts 47, 48, 49.

[0070] The opening 514 is for fastening another conductive plate, in particular a copper plate, etc., and then it forms the shaping of the interface of the completed transformer 30. The opening 514 can have an internal thread in the mounting receiving unit 51.

[0071] In addition, the mounting receiving unit 51 has an opening 515, which can be used to cool the rectifier 40. For cooling, a liquid or gaseous medium, in particular water, oil or air, etc., can be used as the cooling medium.

[0072] The side parts 47, 48 have an asymmetric thickness in order to clamp one or two semiconductor modules 401 each. Therefore, in the rectifier 40 according to Figures 3 to 5 , the side parts 47, 48 are each designed asymmetrically. In Figures 3 to 5 , the side parts 47, 48 are arranged such that two semiconductor modules 401 can be clamped by the side parts 47, 48, as mentioned above. For this purpose, the A side part 47 is Figure 3 arranged on the left side of the intermediate part 49. In addition, the B side part 48 isFigure 3 is arranged on the right side of the intermediate member 49.

[0073] At least one fastening element 471 is provided on the A-side member 47, by means of which the transformer 30 can be conductively fastened to the rectifier 40, in particular can be screwed to the rectifier 40 by means of a screw. The opening 472 can be used for cooling the rectifier 40. For cooling, a liquid or gaseous medium, in particular water, oil or air, etc., can be used as the cooling medium.

[0074] At least one fastening element 481 is provided on the B-side member 48, by means of which the transformer 30 can be conductively fastened to the rectifier 40, in particular can be screwed to the rectifier. The opening 482 can be used for cooling the rectifier 40.

[0075] As can be seen more precisely from Figure 4 the transformer 30 can be fastened to the rectifier 40 by means of the fastening element 471 at up to two fastening sites. In addition, the transformer 30 can be fastened to the rectifier 40 by means of the fastening element 481 at up to two fastening sites. The openings 472, 482 are spaced apart from each other by distances a, b, c, d, as described in Figure 4 One of the two openings 472, 482 forms a delivery part or inlet for the cooling medium to the rectifier 40. Each of the other two openings 472, 482 forms an outlet for the cooling medium to the rectifier 40A.

[0076] In the rectifier 40, fastening elements 511 to 514 (in the form of screws and / or rivets) are provided on the mounting plate 51, so that the side members 47, 48 and the intermediate member 49 can be fastened to one of the mounting receiving units 51, 52 for two mounting variants of the side members 47, 48. Other mounting variants are subsequently referred to Figures 6 to 8 described.

[0077] Alternatively, it is possible to use a slotted hole solution as the fastening elements 471, 481 and / or 511 to 513 in order to enable the mounting of the side members 47, 48 for two different positions. This is described in more detail in Figures 7 to 9 According to a further alternative, two screw holes can be used in the transformer 30. In addition, even when the fastening elements 511, 513 and the side members 47, 48 have slotted holes as fastening openings, for Figures 3 to 5 the transformer variant (with pole switching) and for Figures 6 to 8 the transformer variant (without pole switching), the same fastening openings can still be used on the transformer 30.

[0078] Figures 6 to 8The structure of the rectifier 40A without pole switching or polarity switching is shown. The rectifier 40A is constructed in the same manner as previously described for the previous embodiments in a plurality of components, i.e., an embodiment with pole switching for the rectifier 40.

[0079] Differently from the previous embodiments, in the Figures 6 to 8 rectifier 40A, the side components 47, 48 are arranged interchangeably with respect to the intermediate component 49. Thus, Figure 6 the A-side component 47 in Figure 6 is now arranged on the right side of the intermediate component 49. Further, Figures 6 to 8 the B-side component 48 in Figure 7 is now arranged on the left side of the intermediate component 49. Thus, in the

[0080] embodiment, only two semiconductor modules 401 can be provided in total. Here, only one semiconductor module 401 is arranged between the A-side component 47 and the intermediate component 49. Similarly, only one semiconductor module 401 is arranged between the B-side component 48 and the intermediate component 49. Therefore, for the connection plug connector 402, in

[0081] only two connection tabs or direct plug connectors 4013 of the semiconductor module 401 can be seen. Figure 7 and Figure 8 As a result, in the rectifier 40A, only two semiconductor modules 401 are forced to be cancelled by simply interchanging the side components 47, 48. Thus, a function without pole switching or polarity switching can be achieved, as already mentioned for the previous embodiments. Figure 1 In the Figure 1 pole-switching-free variants of

[0082] and

[0083] only the Figure 2 transistors 42, 44 of Figure 6 are required. Alternatively, only the Figure 6 transistors 41, 43 of Figure 2 can be used.

[0084] In the rectifier 40, fastening elements 521 to 524 are also provided in the form of screws and / or rivets on the mounting receiving unit 52. In addition, the mounting receiving unit 52 has an opening 525, which can be used for cooling the rectifier 40A.

[0085] Accordingly, in Figure 6 , in the rectifier 40A, the side parts 47, 48 and the intermediate part 49 are fastened to the mounting receiving unit 52 by means of the fastening elements 521 to 523. Here, the side parts 47, 48 (regardless of whether they are placed on the left or right of the intermediate part 49 or vice versa) are fastened to the mounting receiving unit 52 by means of an insulating part, in particular implemented as at least one insulating disc 450. The fastening elements 521 to 523 are screws in the Figure 2 example, which are fastened in the openings of the side parts 47, 48, the intermediate part 49 and the mounting receiving unit 52. Based on the required insulation between the side parts 47, 48 and the mounting receiving unit 52, the fastening elements 521 and 523 require additional insulating discs 450 for the non-contact but fixed mounting of the individual parts 47, 48, 49.

[0086] Thereby, the structure of the rectifiers 40, 40A can be implemented very flexibly and inexpensively for the respectively required applications. Here, at the output, a common part of the semiconductor module 401 can be used for the welding transformer 30 with or without pole switching or polarity switching.

[0087] Accordingly, in the rectifiers 40, 40A, the same transistors or semiconductor modules 401, in particular MOSFET modules, can be used for all transistors 41 to 44 by placing plug-in parts or connecting plug connectors 402 on the semiconductor module 401.

[0088] In addition, the transformer 30 with pole switching and the transformer 30 without pole switching can be implemented using the rectifiers 40, 40A with the same side parts 47, 48. In other words, regardless of whether the transformer 30 with pole switching and the transformer 30 without pole switching are combined with the rectifiers 40, 40A, the same parts are used for the rectifiers 40, 40A.

[0089] For this purpose, the transformer 30 with pole switching and the transformer 30 without pole switching can be controlled by the same drive circuit board 403 (with equipment variants), as mentioned before.

[0090] Figure 9Shows a welding device 3 with a rectifier 400 according to a third embodiment. The welding device 3 is in particular a resistance welding device. The welding device 3 is constructed in multiple components in the same way as described for the welding device 2 according to the previous embodiment. The components 41, 42, 43, 44 (which are implemented as modules 401 and thus as general-purpose components) here have at least one transistor, but in particular up to about 50 transistors. However, the quantity can be arbitrarily selected according to the requirements of the respective welding application. BODY diodes are drawn in all components 41, 42, 43, 44.

[0091] Different from the welding device 2 according to the previous embodiment, in the welding device 3 according to the current embodiment, the transistors 41, 42, 43, 44 are each specifically designed as metal-oxide-semiconductor field-effect transistors (MOS-FETs). The metal-oxide-semiconductor field-effect transistors are connected in reverse parallel in the welding device 3.

[0092] Figure 9 Shows a variant with pole switching. If a variant without pole switching is to be implemented, then only transistors 42, 44 are required, where the source interface S is connected to the transformer 30, and the drain interface is connected to the respective electrodes 11, 12.

[0093] As shown in Figure 9 the primary voltage U1 on the primary side of the welding transformer 30 is generated by a bridge circuit 60 of semiconductor switches 61, 62, 63, 64. The semiconductor switches 61, 62, 63, 64 can in particular each be insulated-gate bipolar transistors (IGBT = Insulated-Gate Bipolar Transistor) of an inverter.

[0094] In the circuit 60, the first semiconductor switch 61 and the second semiconductor switch 62 are connected in series. In addition, the third semiconductor switch 63 and the fourth semiconductor switch 64 are connected in series. A primary voltage U1 on the primary side of the welding transformer 30 is formed between a first connection node 71 (which is arranged between the first and second semiconductor switches 61, 62) and a second connection node 72 (which is arranged between the third and fourth semiconductor switches 63, 64).

[0095] On the secondary side of the welding transformer 30, a first secondary voltage U21 exists between the first and second output terminals 31, 32 of the welding transformer 30. In addition, a second secondary voltage U22 exists between the second and third output terminals 32, 33 of the welding transformer 30. The first secondary voltage U21 and the second secondary voltage U22 form a welding voltage U23 of a preselected polarity after being rectified by the rectifier 400.

[0096] The welding transformer 30 converts the primary voltage U1 into first and second secondary voltages U21, U22. Here, the sum of the secondary voltages U21, U22 is less than the value of the primary voltage U1. In addition, the welding transformer 30 converts the primary current I1 on the primary side of the welding transformer 30 into a secondary current I2 on the secondary side of the welding transformer 30. The secondary current I2 (which can also be referred to as the welding current) has a higher value than the primary current I1.

[0097] The circuit shown in Figure 9 the welding device 3 is connected by the control device 20 in the same way as described for the previous embodiment.

[0098] Instead of the welding device 2 according to the previous embodiment, the welding device 3 can be used in the facility 1 according to the previous embodiment. The rectifier 400 can in particular be designed in the same way as described for the first and second embodiments.

[0099] The welding device 3 can also be used particularly advantageously in a sheet combination, in which different degrees of burnout of the welding electrodes result in the welding tongs. In addition, the welding device 3 can be used particularly advantageously in the welding of links and in the welding of heating bodies.

[0100] Thus, it is possible that two of the at least two semiconductor modules 401 are arranged together between one of the side members 47 and the intermediate member 49 and are connected as a series circuit composed of two transistors 41, 42 between the welding tool 10 and one output terminal 31 of the welding transformer 30, and two other semiconductor modules 401 are arranged together between the other side member 48 and the intermediate member 49 and are connected as a series circuit composed of two transistors 43, 44 between the welding tool 10 and the other output terminal 33 of the welding transformer 30. Thereby, pole switching of the transformer 30 is possible, as described previously for the first embodiment. If pole switching of the transformer 30 is not required, then at least two semiconductor modules can be arranged individually between one of the side members 47, 48 and the intermediate member 49 and connected between the welding tool 10 and the output terminals of the welding transformer 30.

[0101] Furthermore, it is possible that the welding transformer 30 has at least two, but preferably three, output terminals, where series circuits each composed of two transistors 41, 42; 43, 44 are respectively arranged on two of the output terminals. The ends of the series circuits are connected to each other, and are connected to or before the welding tool 10 using the preferably third output terminal of the welding transformer 30. Furthermore, it is possible that the series circuits of the transistors 41, 42; 43, 44 are composed of only one or more transistors connected in parallel with the same polarity. Furthermore, for the variant without pole switching, as described with reference to Figure 6 and Figure 7 as described, on two of the output terminals 31, 33, each is composed of only one transistor.

[0102] All of the previously described designs of the facility 1, the welding devices 2, 3, and the method for resistance welding performed thereby can be used individually or in all possible combinations. In particular, all features and / or functions of the previously described embodiments can be combined arbitrarily. Additionally, subsequent modifications are especially conceivable.

[0103] The components shown in the drawings are schematically shown and can be different in exact design from the form shown in the drawings, as long as their previously described functions are ensured.

[0104] The transistors 41, 42, 43, 44 can alternatively be bipolar transistors, where however, an embodiment as a metal-oxide-semiconductor field-effect transistor (MOS-FET) is preferred.

[0105] The welding transformer 30 can be constructed from a parallel circuit of two transformers.

[0106] Possibly, up to four semiconductor modules 401 are arranged between the side members 47, 48 and the intermediate member 49. Obviously, the number of semiconductor modules 401 can be larger according to requirements and design. Additionally, for special applications, 3 or 5 or more semiconductor modules 401 can be arranged between the side members 47, 48 and the intermediate member 49.

[0107] Instead of the welding tool 10 controlled by the device 50, the facility 1 may have a manual tool. The device 50 can alternatively be designed such that the welding tool 10 is a hand-held tool.

[0108] In addition to one of the mentioned implementation variants for the welding tool 10, it is also conceivable that the facility 1 has at least one additional tool, such as a screw, drilling or milling tool, or a riveting tool or a cutting tool or a decontamination tool (Toxwerkzeug) or a stamping tool.

Claims

1. A rectifier (40; 40A, 400) for a welding transformer (30) of a welding device (2; 3) for welding at least one component (5, 6), the rectifier having: A first side component (47) for conductively connecting to the welding transformer, A second side component (48) for conductively connecting to the welding transformer, An intermediate component (49) arranged between the first and second side components (47, 48) and designed for current output in the direction of the welding electrodes of the welding device, and At least two semiconductor modules (401) connected between an output of a welding tool (10) of the welding device (2; 3) and an output of the welding transformer (30), Wherein at least one of the at least two semiconductor modules (401) is arranged between the intermediate component (49) and the first side component (47), Wherein at least one of the at least two semiconductor modules (401) is arranged between the intermediate component (49) and the second side component (48), and wherein the first side component (47) and the second side component (48) are designed asymmetrically such that an exchange of the arrangement structure of the side components (47, 48) relative to the intermediate component (49) changes the number of semiconductor modules (401) that can be clamped between one of the side components (47, 48) and the intermediate component (49).

2. The rectifier (40; 40A, 400) according to claim 1, wherein, When the first side component (47) is arranged to the left of the intermediate component (49) and the second side component (48) is arranged to the right of the intermediate component (49), there is space for arranging two of the at least two semiconductor modules (401) between the first side component (47) and the intermediate component (49), and there is space for arranging two of the at least two semiconductor modules (401) between the second side component (48) and the intermediate component (49), Wherein, when the first side component (47) is arranged to the right of the intermediate component (49) and the second side component (48) is arranged to the left of the intermediate component (49), there is space for arranging only one of the at least two semiconductor modules (401) between the first side component (47) and the intermediate component (49), and there is space for arranging only one of the at least two semiconductor modules (401) between the second side component (48) and the intermediate component (49).

3. The rectifier (40; 40A, 400) according to claim 1 or 2, wherein, The at least two semiconductor modules (401) are designed as universal parts, which are either arranged together between one of the side parts and the intermediate part (49) and connected as a series circuit composed of two transistors (41, 42; 43, 44) between the welding tool (10) and the output terminals of the welding transformer (30), or the at least two semiconductor modules are respectively arranged individually between one of the side parts and the intermediate part (49) and connected between the welding tool (10) and the output terminals of the welding transformer (30).

4. The rectifier (40; 40A, 400) according to claim 3, wherein, The at least two semiconductor modules (401) each have at least one transistor (41 to 44), and wherein the polarity of one transistor (42; 44) of the series circuit is rotated relative to the polarity of the other transistor (41; 43) of the series circuit so as to achieve a weld voltage (U23) with switchable polarity and a weld current (I2) with switchable polarity on the welding transformer (30) in the case of the series circuit.

5. The rectifier (40; 40A, 400) according to claim 4, wherein, The transistors (42; 44) with rotated polarity are arranged via the intermediate part (49) and the mounting receiving unit (51) for connection to the welding tool (10).

6. The rectifier (40; 40A, 400) according to claim 3, wherein, The transistors (41, 42; 43, 44) are metal-oxide-semiconductor field effect transistors.

7. The rectifier (40; 40A, 400) according to claim 1 or 2, further comprising fastening elements (471, 481) for fastening the side members (47, 48) to the welding transformer (30), wherein, The fastening elements (471, 481) are arranged on the side parts (47, 48) such that the same fastening points can be used on the welding transformer (30) regardless of how the side parts (47, 48) are arranged relative to the intermediate part (49), whereby a weld current (I2) with switchable polarity can or cannot be achieved.

8. A welding device (2; 3), comprising:[[]] A welding tool (10) with at least one welding electrode (11, 12), the welding electrode being in contact with at least one component (5, 6) for welding. At least one welding transformer (30) for delivering current to the welding tool (10) when welding at least one component (5, 6), and At least one rectifier (40; 40A, 400) according to any one of the preceding claims. Among them, At least one rectifier (40; 40A, 400) is connected to at least one welding transformer (30).

9. The welding device (2; 3) according to claim 8, wherein, The welding transformer (30) has two output terminals (31, 33), on which a series circuit composed of two transistors (41, 42; 43, 44) is respectively connected before the welding tool (10).

10. The welding device (2; 3) according to claim 9, further comprising a control device (20) for turning on at least one serially connected transistor (41, 42, 43, 44) in a negatively conductive manner in terms of current during synchronous operation.

11. The welding device (2; 3) according to any one of claims 8 to 10, wherein, The welding tool (10) is a welding tong with two welding electrodes (11, 12), and at least one component (5, 6) is arranged between the welding electrodes during welding.

12. A facility (1) for processing an object (4), comprising:[[]] The welding device (2; 3) according to any one of claims 8 to 11. Among them, The welding device (2; 3) is provided for welding at least one component (5, 6), which is provided for processing at least one object (4) therein.

13. The facility (1) according to claim 12, wherein, The facility (1) is designed for manufacturing a vehicle body-in-white or a heating body or a chain as the object (4).

14. A method for a rectifier (40; 40A, 400) according to any one of claims 1 to 7 for a welding transformer (30) of a welding device (2; 3), wherein the method has the following steps: Arranging an intermediate member (49) between a first and a second side member (47, 48), and arranging at least two semiconductor modules (401) between the intermediate member (49) and the first and second side members (47, 48), wherein the first side member (47) and the second side member (48) are designed asymmetrically such that an exchange of the arrangement structure of the side members (47, 48) relative to the intermediate member (49) changes the number of semiconductor modules (401), which can be clamped between one of the side members (47, 48) and the intermediate member (49), and electrically connecting at least two semiconductor modules (401) between an output of a welding tool (10) and a welding transformer (30).

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