Method for manufacturing a contact element and / or a stator-side busbar

Abstract

The invention relates to a method for producing a contact element (8) and / or a stator-side busbar (26) for a high-voltage interface (10), which serves to represent an electrical connection between a stator (25) with the stator-side busbar (26) and a housing-side connection piece (30) of a high-voltage electronics system (35). In order to simplify the production of the contact element (8), a strip of electrically conductive sheet material is formed in such a way that a helical tolerance compensation structure (38) is produced on the contact element (8), which is designed and arranged in such a way that the contact element (8) in an installed state can not only compensate for tolerances along a longitudinal axis (36) of the contact element (8), but also for misalignments of the connecting piece (30) relative to the contact element (8).

Description

[0001] The invention relates to a method for producing a contact element and / or a stator-side busbar for a high-voltage interface, which serves to represent an electrical connection between a stator with the stator-side busbar and a housing-side connection piece of a high-voltage electronics system. State of the art

[0002] German patent application DE 10 2019 207 438 A1 discloses an electrically assisted turbocharger comprising a compressor housing, a stator core of an electric motor coupled to the turbocharger, which is connected to the compressor housing, and an electronics housing of the electric motor, which is connected to the stator core. European patent application EP 3 641 068 B1 discloses a connector with a connection plug and a connection socket, which comprises an annular socket part and a lamella cage arranged at least partially inside the annular socket part. Disclosure of the invention

[0003] The object of the invention is to simplify the production of a contact element and / or a stator-side busbar for a high-voltage interface, which serves to represent an electrical connection between a stator with the stator-side busbar and a housing-side connection piece of a high-voltage electronics system.

[0004] The object is achieved in a method for producing a contact element and / or a stator-side busbar for a high-voltage interface, which serves to create an electrical connection between a stator with the stator-side busbar and a housing-side connection piece of high-voltage electronics, in that a strip of electrically conductive sheet material is formed in such a way that a helical tolerance compensation structure is produced on the contact element, which is designed and arranged in such a way that the contact element, in an installed state, can not only compensate for tolerances along a longitudinal axis of the contact element, but also for misalignments of the connection piece relative to the contact element. The helical tolerance compensation structure is designed essentially in the shape of a circular cylinder shell, at least at its opposite ends.Between its opposite ends, the helical tolerance compensation structure can have a reduced or enlarged diameter. The helical tolerance compensation structure can have a substantially constant diameter along its longitudinal axis, at least when the contact element is unloaded. In the loaded state, particularly when installed, the shape of the helical tolerance compensation structure can change to enable the desired tolerance compensation. This significantly simplifies the assembly of the high-voltage interface. The deliberately permitted change in the shape of the tolerance compensation structure is brought about, on the one hand, by the helical shape. Furthermore, the material from which the contact element is formed, at least in the area of ​​the helical tolerance compensation structure, is elastically deformable to a limited extent.A helix used to represent the helical tolerance compensation structure can comprise a helical cut in the essentially circular-cylindrical tolerance compensation structure. However, the helix can also comprise more than one helical cut. This can improve the tolerance compensation capacity. However, designing the tolerance compensation structure with multiple helical cuts is also more expensive to manufacture. High-voltage interfaces refer to electrical connections that operate with alternating voltages of over thirty volts to one thousand volts or with direct voltages of over sixty volts to one thousand five hundred volts. High safety requirements must be ensured here, particularly with regard to contact protection. The strip of electrically conductive sheet material, which is a starting product in the manufacture of the contact element, preferably has the shape of an elongated rectangle.The strip of electrically conductive sheet material is preferably manufactured cost-effectively, for example, by stamping. The strip of electrically conductive sheet material can be formed relatively inexpensively to create the desired helical tolerance compensation structure in the contact element.

[0005] A preferred embodiment of the method is characterized in that the strip is punched from the electrically conductive sheet material to create a basic shape of the contact element in the electrically conductive sheet material. Thus, a plurality of strips can advantageously be produced in a single process step using a suitable punching device.

[0006] A further preferred embodiment of the method is characterized in that the strip of electrically conductive sheet material is provided with at least one longitudinal slot. The longitudinal slot is preferably created in the electrically conductive sheet material together with the previously described punching process. The longitudinal slot is preferably arranged centrally in the sheet metal strip. The longitudinal slot in the center of the sheet metal strip provides the finished contact element with sufficient elasticity to provide the desired tolerance compensation function.

[0007] A further preferred embodiment of the method is characterized in that the strip of electrically conductive sheet material is repeatedly bent around the longitudinal axis of the contact element. This results in a substantially circular cylindrical shell-shaped shape of the bent sheet material with the desired helical tolerance compensation structure.

[0008] A further preferred embodiment of the method is characterized in that the strip of electrically conductive sheet material is bent at an end facing the connecting piece before being rounded such that, after rounding, this end takes on the shape of a circular ring with a through-hole. The circular ring with the through-hole serves to form a screw connection point, to which the end of the contact element facing the connecting piece can be attached to the connecting piece in a simple, electrically conductive and very stable manner, for example with the aid of a screw. Particularly advantageously, the circular ring does not have to be completely closed in the circumferential direction. This considerably simplifies production. For example, it is sufficient if only a relatively large segment is bent, which serves to form the screw connection point.It is also possible and possibly advantageous if several segments are angled at the end of the strip of electrically conductive sheet material facing the connecting piece, which serve to represent the screw connection point.

[0009] A further preferred embodiment of the method is characterized in that the strip of electrically conductive sheet material is formed into a multifunctional sleeve at an end facing away from the connection piece during the round bending process. The multifunctional sleeve essentially has the shape of a straight circular cylinder shell. The multifunctional sleeve is preferably connected to the contact element as one piece. However, it is also possible for the multifunctional sleeve to be connected to the contact element in another way, for example by a material fit. The electrically conductive connection of the multifunctional sleeve to the busbar is preferably made by a material fit. Depending on the design, the multifunctional sleeve can also be connected to the busbar in another way, for example by a force fit, a form fit, or even as one piece. In addition to its electrical conduction function, the multifunctional sleeve performs at least one further function at the high-voltage interface.This additional function preferably includes at least a sealing function. Furthermore, the multifunctional sleeve advantageously also serves to position the tolerance compensation structure formed on the contact element relative to the connecting piece in such a way that the electrically conductive connection between the end of the contact element facing the connecting piece and the connecting piece is established, preferably with the aid of a screw.

[0010] A further preferred embodiment of the method is characterized in that the busbar is provided at a first end with a through-hole, which represents a multifunctional sleeve that is assigned to an end of the contact element facing away from the connection piece. The through-hole is advantageously realized on the busbar by forming, in particular by deep drawing. The multifunctional sleeve on the busbar is advantageously designed in the same way as, or similar to, the previously described multifunctional sleeve on the contact element. A connection between the multifunctional sleeve and the contact element is preferably designed with a material fit. The material fit is created, for example, by welding.

[0011] A further preferred embodiment of the method is characterized in that the busbar is provided with a crimp geometry at a second end. The crimp geometry simplifies the connection of a stator line to the busbar. The crimp geometry at the second end of the busbar is preferably produced by forming.

[0012] A further preferred embodiment of the method is characterized in that the crimp geometry has two semicircularly curved wings that are integrally connected to each other at their mutually facing ends. This further simplifies the production of the high-voltage interface.

[0013] In a contact element and / or a busbar manufactured according to a method described above, the above-mentioned object is achieved alternatively or additionally in that the contact element, in addition to the helical tolerance compensation structure, has a high current conduction function and a screw-on surface at its end facing the connecting piece. The claimed contact element is simple and cost-effective to manufacture. Furthermore, the tolerance compensation structure enables the simple and effective compensation of unavoidable or cost-effective tolerances during installation of the contact element. Short description of the drawing

[0014] They show: Fig. 1 a high-voltage interface to illustrate an electrical connection between a stator and a housing-side connection piece of an air supply device in longitudinal section; Fig. 2 a perspective view of the air supply device with a housing comprising a high-voltage interface with three contact elements; Fig. 3 a perspective view of a contact element which is electrically connected at one end to one end of a busbar; Fig. 4 a perspective view of the contact element from Fig. 3 in an unloaded or unassembled state; Fig. 5 the contact element Fig. 4 in a loaded condition such as may occur in the assembled state; Fig. 6 a perspective view of a contact unit with three contact elements attached to a tempering sleeve; Fig. 7 a perspective view of the contact unit from Fig. 6 from the back; Fig. 8 a perspective view of a connection unit with three support cylinders for the three contact elements; Fig. 9 a perspective view of a combination plug unit with a plug seal; Fig. 10 is a perspective view of a strip of electrically conductive sheet material provided with a longitudinal slot, which serves to represent a contact element with a helical tolerance compensation structure; Fig. 11 the rounded sheet metal strip from Fig. 10 with the desired helical tolerance compensation structure; the Fig. 12 to 14 show three embodiments, such as a screw connection point, on a Fig. 11 right end of the contact element 8 can be realized; Fig. 15 is a perspective view of a busbar with a multifunctional sleeve at a first end and a crimp geometry at a second end; and Fig. 16 a perspective view of the busbar from Fig. 15 with the contact element attached to the multifunctional sleeve made of Fig. 11. Description of the embodiments

[0015] In Fig. Figure 2 shows a perspective view of an air supply device 1. The air supply device 1 is also referred to as an air compressor and is used in a mobile fuel cell system to provide compressed air. The mobile fuel cell system, in turn, is used in a motor vehicle equipped with the fuel cell system to provide electrical energy, which is converted, for example, via an electric motor into drive energy for the motor vehicle.

[0016] The air supply device 1 comprises a multi-part housing 2 with an air connection 3 through which air is supplied, and with an air connection 4 through which compressed air is discharged. To compress the air, the air supply device 1 comprises, for example, a compressor wheel that is rotatable within a compressor volute.

[0017] The compressor wheel is driven, optionally with the assistance of a turbine wheel, by an electric motor arranged in the housing 2. The electric motor comprises a rotor that is rotatable within a stator.

[0018] The stator of the electric motor comprises a power connection device 5, via which alternating current is supplied to the stator in three phases. The power connection device 5 is connected to a control connection device 6 via a connecting device comprising three elongated contact elements 7, 8, 9. The contact elements 7, 8, 9 serve to form a high-voltage interface 10 between the stator and a high-voltage electronics system.

[0019] The high-voltage electronics includes an inverter. The control connection device 6 is combined, for example, with a cable outlet, which, as indicated by three outgoing cables, is connected to a separately arranged and Fig. 2 is connected to an inverter not shown. However, the inverter can also be integrated into the housing 2 of the air supply device 1.

[0020] In Fig. Figure 1 shows the high-voltage interface 10 in longitudinal section through the contact element 8. The housing 2 of the air supply device comprises two housing bodies 11, 12. The housing body 11 serves, among other things, to accommodate an electric motor drive for the air supply device. The housing body 12 serves, for example, to rotatably accommodate an impeller, in particular a compressor wheel, which is driven by the electric motor drive in the air supply device.

[0021] From a summary of the Fig. 1, Fig. 6 and Fig. 7 shows that a total of three contact elements 7, 8, 9 are connected in an electrical contact unit 14, each with a busbar 26. The electrical contact unit 14 is mounted on a tempering sleeve 24, which in the housing body 11 has a stator arrangement 20 with a Fig. 1 only by a reference numeral 25. Since the tempering sleeve 24 primarily serves to cool the stator 25, it is also referred to as a cooling sleeve 24.

[0022] The stator 25 comprises stator windings and winding heads from which stator leads emanate. One of the stator leads is in the Fig. 1, is electrically connected to a radially inner end of the busbar 26. The contact element 8 electrically connects the busbar 26 to a connecting piece 30 of a high-voltage electronics unit 35, which is also only indicated by a reference numeral. The high-voltage electronics unit 35 comprises an inverter.

[0023] In Fig. 3, the busbar 26 is shown in perspective together with the contact element 8 attached to it. Fig. 3 upper end of the busbar 26, the contact element 8 is firmly connected to the busbar 26. At a Fig. 3 A crimp sleeve 45 is formed at the lower end of the busbar 26. The crimp sleeve 45 serves for the electrical connection of a stator cable (not shown).

[0024] The contact element 8 has a multifunctional sleeve 16 at its end facing the busbar 26. The multifunctional sleeve 16 is Fig. 3 left end is connected in an electrically conductive manner to the busbar 26, preferably by welding.

[0025] In the perspective representation of the Fig. 4 you can see that the contact element 8 is at its Fig. 3 right end has a circular disc 28 with a through hole 29. At the same end, the contact element 8 has a first conical section 41. A second conical section 42 is formed with the contact element 8 between a helical tolerance compensation structure 38 and the multifunctional sleeve 16.

[0026] In the Fig. 4 and Fig. Figure 5 illustrates how the contact element 8 can deform in the area of ​​the helical tolerance compensation structure 38 during assembly when a load acts on the contact element 8 with the tolerance compensation structure 38. Such a load occurs, for example, when tolerances along a longitudinal axis 36 or misalignments of the connecting piece 30 must be compensated.

[0027] Depending on the type of production, such tolerances cannot be avoided or can only be avoided at increased cost.

[0028] In Fig. 3, the view of the longitudinal axis 36, which is not visible there, is shown only for illustration purposes. The contact element 8 with its longitudinal axis 36 is, as can be seen in Fig. 3, arranged perpendicular to the longitudinal extent of the busbar 26.

[0029] In Fig. 1 you can see that the contact element 8 is at its Fig. 1 right end is attached to the connecting piece 30 by means of a screw 31. A screw head of the screw 31 is arranged inside the tolerance compensation structure 38. A screw shaft of the screw 31 is screwed into a corresponding threaded blind hole in the connecting piece 30. This ensures a stable and electrically conductive permanent connection between the contact element 8 and the connecting piece 30 in a simple manner.

[0030] The helical tolerance compensation structure 38 of the contact element 8 is arranged within a support cylinder 40. There is sufficient play between the support cylinder 40 and the tolerance compensation structure 38 to allow movements and / or changes in the shape of the contact element 8 in the area of ​​the tolerance compensation structure 38. Such a change in shape results, for example, from a synopsis of the Fig. 4 and Fig. 5.

[0031] A plug seal 18, an inner seal 21, and an outer seal 22 are provided to seal the high-voltage interface 10. The plug seal 18 is pressed into a receiving space 17 provided for this purpose in the multifunctional sleeve 16 with the aid of a plug of a combination plug unit 23. The plug of the combination plug unit 23 serves, in particular, to support the plug seal 18 in the receiving space 17 of the multifunctional sleeve 16 in such a way that the plug seal 18 is not undesirably deformed.

[0032] Radially outward, the multifunctional sleeve 16 has a support section 19 on which the inner seal 21 is arranged. The inner seal 21 is designed as an internal single seal and arranged in an annular space that is bounded radially inward by the multifunctional sleeve 16. Radially outward and in both axial directions, this annular space is bounded by the electrical contact unit 14.

[0033] The outer seal 22 is arranged radially outside the inner seal 21. The outer seal 22 is designed as an outer collective seal and is arranged in an annular space that is bounded radially inward by the electrical contact unit 14 and radially outward by the housing body 11.

[0034] The conical sections 41 and 42 enable damage-free mounting of the inner seal 21 onto the multifunctional sleeve 16. A third conical section 43 enables damage-free mounting of the plug seal 18 with the combination plug unit 23.

[0035] A sealing shoulder 27 in the housing body 11 ensures that the outer seal 22 maintains its desired position.

[0036] In the Fig. 6 and Fig. Figure 7 shows how the outer seal 22, designed as an outer collective seal, together with the three contact elements 7, 8, 9 and a sensor connection point 48, are attached to the electrical contact unit 14. The electrical contact unit 14, in turn, is attached to the temperature control sleeve 24. Furthermore, screw points are provided at which the electrical contact unit 14 is attached to the housing 2.

[0037] In Fig. 8 shows a connection unit 50 with a total of three support cylinders 40 for the three contact elements in perspective.

[0038] In Fig. Figure 9 shows a perspective view of the plug seal 18 combined with the combination plug unit 23. The combined plug seal 18 includes a separate plug seal for each contact element.

[0039] In Fig. Figure 10 shows a perspective view of a strip 61 made of electrically conductive sheet metal 60 and provided with a longitudinal slot 62. The strip 61 can be easily produced in large quantities using a stamping process with minimal manufacturing effort. The slotted strip 61 can then be bent round using a simple bending technique and Fig. 11 right end to be reshaped.

[0040] The Fig. The helical tolerance compensation structure 38 shown in Figure 11 is created on the contact element 8 by wrapping the strip 61 of sheet metal 60, provided with the longitudinal slot 62, several times around its own axis. The longitudinal slot 62 in the center of the sheet metal strip 61 provides the finished contact element 8 with the tolerance compensation structure 38 with sufficient elasticity to achieve the desired tolerance compensation.

[0041] To produce the circular disc 28, which serves to represent a screwing surface, a front area of ​​the angled sheet metal strip is bent either completely or in multiple segments, as shown in the Fig. 12, Fig. 13, and Fig. 14 is shown.

[0042] Fig. 12 shows a large segment 64 extending almost over the entire circumference at the end of the contact element 8 to represent the circular disc 28 with the through hole 29. In Fig. 13, three segments 67, 68, 69 are evenly distributed over the circumference at the end of the contact element 8. In Fig. 14 shows the circular disc 28 with the through hole 29 with two opposite segments 65, 66.

[0043] In the Fig. 15 and Fig. Figure 16 illustrates that the multifunctional sleeve 16, which together with the plug seal 18, the inner seal 21, and the outer seal 22 serves to seal the high-voltage interface 10, has been relocated to the contact element 8 in the busbar 26. This provides, among other advantages, that the contact element 8 can be designed in a simpler and thus more cost-effective manner.

[0044] The multifunctional sleeve 16 is designed as a passage 70 in the Fig. 15 left end and in Fig. 16 upper end of the busbar 26. A crimp geometry 71 is formed at the other end of the busbar 26. The crimp geometry 71 comprises two wings 72, 73, which are bent to form a crimp sleeve and welded at their mutually facing ends by a weld seam 74. Fig.16 shows the busbar 26 combined with the contact element 8. The connection between the multifunctional sleeve 16 and the contact element 8 is made, for example, by welding. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2019 207 438 A1

[0002] EP 3 641 068 B1

[0002]

Claims

[1] Method for producing a contact element (8) and / or a stator-side busbar (26) for a high-voltage interface (10), which serves to represent an electrical connection between a stator (25) with the stator-side busbar (26) and a housing-side connection piece (30) of a high-voltage electronics system (35), characterized by that a strip (61) made of an electrically conductive sheet material (60) is deformed in such a way that a helical tolerance compensation structure (38) is produced on the contact element (8), which is designed and arranged in such a way that with the contact element (8) in an installed state not only tolerances along a longitudinal axis (36) of the contact element (8) can be compensated, but also misalignments of the connecting piece (30) relative to the contact element (8). [2] Method according to claim 1, characterized bythat the strip (61) is punched from the electrically conductive sheet material (60) in order to produce a basic shape of the contact element (8) in the electrically conductive sheet material (60). [3] Method according to one of the preceding claims, characterized by that the strip (61) of electrically conductive sheet material (60) is provided with at least one longitudinal slot (62). [4] Method according to one of the preceding claims, characterized by that the strip (61) of electrically conductive sheet material (60) is bent several times around the longitudinal axis (36) of the contact element (8). [5] Method according to claim 4, characterized by that the strip (61) of electrically conductive sheet material (60) is angled at an end facing the connecting piece (30) before the round bending so that after the round bending the shape of a circular ring disc (28) with a through hole (29) results at this end. [6] Method according to claim 4 or 5, characterized by that the strip (61) made of the electrically conductive sheet material (60) is formed into a multifunctional sleeve (16) at an end facing away from the connecting piece (30) during round bending. [7] Method according to claim 4 or 5, characterized by that the busbar (26) is provided at a first end with a passage (70) which represents a multifunctional sleeve (16) which is assigned to an end of the contact element (8) facing away from the connecting piece (40). [8] Method according to one of the preceding claims, characterized by that the busbar (26) is provided with a crimping geometry (71) at a first end. [9] Method according to claim 8, characterized by that the crimping geometry (71) has two semicircularly curved wings (72, 73) which are materially connected to one another at their mutually facing ends. [10] Contact element (8) and / or a busbar (26), manufactured according to a method according to one of the preceding claims, characterized by that the contact element (8), in addition to the helical tolerance compensation structure (38), has a high current conduction function and a screwing surface at its end facing the connecting piece (30).

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