Interface device for an electric motor or an e-axle of a vehicle and manufacturing process for an interface device for an electric motor or an e-axle of a vehicle

Abstract

The invention relates to a manufacturing process for an interface device for an electric motor of a vehicle, wherein at least one busbar (22) of the subsequent interface device and at least one magnetic flux concentrator (20), which is arranged respectively on the associated busbar (22), of the subsequent interface device are each at least partially overmoulded by overmoulding the at least one magnetic flux concentrator (20) at least partially with a first moulding compound (24) of a first moulding compound type during a first injection-moulding step; and overmoulding the least one magnetic flux concentrator (20), which is surrounded at least partially by the solidified first moulding compound (24), and the at least one busbar (22), at least sections of which rest in each case on at least one outer surface formed from the solidified first moulding compound (24), at least partially with a second moulding compound (32) of the first moulding compound type or a second moulding compound type during a second injection-moulding step. The invention likewise relates to an interface device for an electric motor of a vehicle, to an electric motor for a vehicle and to an E-axle for a vehicle.

Description

[0001] Description

[0002] title

[0003] The present invention relates to a manufacturing method for an interface device for an electric motor or an electric axle of a vehicle. The invention also relates to an interface device for an electric motor or an electric axle of a vehicle, an electric motor for a vehicle, and an electric axle for a vehicle.

[0004] State of the art

[0005] Fig. 1 shows a representation of a prior art interface for explaining a conventional manufacturing method which is known to the applicant as internal prior art.

[0006] During the manufacture of the interface schematically shown in Fig. 1 according to the prior art, three busbars 10 of the future interface, three magnetic flux concentrators 12 of the future interface, and six sockets 14 of the future interface are at least partially overmolded with a molding compound 16 by performing an injection molding step. Therefore, in the interface shown in Fig.

[0007] 1, the busbars 10, the magnetic flux concentrators 12 and the sockets 14 are each at least partially surrounded by the molding compound 16.

[0008] Disclosure of the invention The present invention provides a manufacturing method for an interface device for an electric motor or an E-axle of a vehicle having the features of claim 1, an interface device for an electric motor or an E-axle of a vehicle having the features of claim 8, an electric motor for a vehicle having the features of claim 10 and an E-axle for a vehicle having the features of claim 11.

[0009] Advantages of the invention

[0010] The present invention implements a variety of different interface devices, each comprising at least one busbar and at least one magnetic flux concentrator, which can each advantageously be used for electrically connecting an electric motor of a vehicle. For example, in an interface device according to the invention, more precise positioning of the at least one busbar relative to the at least one magnetic flux concentrator of the same interface device is possible due to the overmolding of its at least one magnetic flux concentrator with the first molding compound before arranging / adding its at least one busbar to the at least one magnetic flux concentrator at least partially covered with the solidified first molding compound.In particular, by utilizing the present invention, the respective position of the at least one busbar in relation to the at least one magnetic flux concentrator of the same interface device can be optimized, and the at least one busbar can be easily held in its respective optimized position during overmolding with the second molding compound. A conventional risk of sparks occurring is thus negligible during subsequent operation of the interface device according to the invention. In addition, the present invention ensures good / homogeneous distributability of the second molding compound through the optimal positioning of the at least one busbar in relation to the at least one magnetic flux concentrator of the same interface device, thereby ensuring the formation of reliable insulation for the interface device according to the invention.Since the conventional problem of inhomogeneous molding compound distribution is eliminated when using the invention described here, there is no need to fear deformations due to internal stress on the insulation of the interface device according to the invention during operation. Compared to conventional interface devices, such as the previously discussed prior art, the interface device according to the invention therefore offers more reliable electrical contact for an electric motor of a vehicle.

[0011] It should also be noted that the present invention can be implemented comparatively simply and without requiring more complex equipment than the prior art. The present invention can therefore also be used to reduce manufacturing costs for interface devices.

[0012] In an advantageous embodiment of the manufacturing method, the at least one magnetic flux concentrator is completely covered with the first molding compound and / or the second molding compound during the first injection molding step and / or during the second injection molding step. This ensures, in the embodiment of the manufacturing method described here, that the at least one magnetic flux concentrator, which is generally made of magnetic steel, is reliably protected from unwanted corrosion during operation of the interface device equipped therewith.

[0013] For example, the at least one magnetic flux concentrator can be only partially covered with the first molding compound during the first injection molding step in such a way that at least one part of the at least one magnetic flux concentrator protrudes from the solidified first molding compound after the first injection molding step, while at least one part of the at least one magnetic flux concentrator protruding from the solidified first molding compound is covered with the second molding compound during the second injection molding step. As will become clear from the following description, the processes described here are relatively easy to carry out. Preferably, the at least one busbar is fastened after the first injection molding step and before the second injection molding step to at least one outer surface which is formed from the solidified first molding compound and which mechanically contacts the respective busbar at least in sections.In this way, undesired linear adjustment movements or rotations of the at least one busbar during overmolding with the second molding compound can be reliably prevented.

[0014] Preferably, the at least one busbar is only partially covered with the second molding compound during the second injection molding step, such that at least one partial surface of the at least one busbar is uncovered by the solidified second molding compound after the second injection molding step. This facilitates subsequent electrical contacting of the at least one busbar.

[0015] As an advantageous addition, at least one socket of the subsequent interface device can be at least partially overmolded with the second molding compound during the second injection molding step, together with the at least one magnetic flux concentrator, which is at least partially surrounded by the solidified first molding compound, and the at least one busbar. In this way, an internal volume of the socket, surrounded by the at least one socket, can be easily kept free of the second molding compound during the second injection molding step. All of the processes listed here are easy to implement.

[0016] A corresponding interface device for an electric motor or electric axle of a vehicle also ensures the advantages described above. In particular, in the interface device, the at least one magnetic flux concentrator can be completely covered with the first molding compound and / or the second molding compound.

[0017] Furthermore, an electric motor for a vehicle with such an interface device and an electric axle for a vehicle with a corresponding interface device also realize the advantages described above. Brief description of the drawings

[0018] Further features and advantages of the present invention are explained below with reference to the figures. They show:

[0019] Fig. 1 is a representation of a prior art interface to

[0020] Explain a conventional manufacturing method;

[0021] Fig. 2A to 2F show representations of starting, intermediate, and final products for explaining a first embodiment of the manufacturing method for an interface device for an electric motor or an electric axle of a vehicle; and

[0022] Fig. 3A and 3B show representations of intermediate and final products for explaining a second embodiment of the manufacturing method for an interface device for an electric motor or an electric axle of a vehicle.

[0023] Embodiments of the invention

[0024] Fig. 2A to 2F show representations of starting, intermediate and final products for explaining a first embodiment of the manufacturing method for an interface device for an electric motor or an electric axle of a vehicle.

[0025] In the manufacturing method described below, at least one magnetic flux concentrator 20 of the later interface device (see Fig. 2A) and at least one busbar 22 of the later interface device (see Fig. 2C) are each at least partially overmolded in at least one injection molding step. The at least one magnetic flux concentrator 20 can be made of a magnetic steel, for example. The at least one busbar 22 can be made of copper, for example. As a rule, for the production of the respective

[0026] Interface device three busbars 22 and three magnetic flux concentrators 20, each of which is arranged on the associated busbar 22, overmolded. However, it should be noted that the feasibility of the method described below is not limited to any specific total number of magnetic flux concentrators 20 and busbars 22 of the later interface device.

[0027] As the at least one injection molding step, in the manufacturing method described below, a first injection molding step is carried out first and later (i.e. after the first injection molding step) a second injection molding step is carried out. During the first injection molding step, the at least one magnetic flux concentrator 20 is at least partially over-molded with a first molding compound 24 of a first molding compound type. The first injection molding step can also be understood as an injection molding step. The first molding compound 24 can be plastic, for example. The over-molding of the at least one magnetic flux concentrator 20 at least partially with the first molding compound 24 takes place during the first injection molding step in such a way that the at least one magnetic flux concentrator 20 is at least partially covered with the first molding compound 24 which is in mechanical contact with the at least one magnetic flux concentrator 20.

[0028] It is expressly pointed out that the first injection molding step is carried out without the presence of the at least one busbar 22 in its later operating position relative to the respectively assigned magnetic flux concentrator 20. This can also be described as the first injection molding step being carried out without the at least one busbar 22 of the later interface device or in the absence of the at least one busbar 22 of the later interface device.

[0029] Since only the at least one magnetic flux concentrator 20, but not the at least one busbar 22, is overmolded with the first molding compound 24 during the first injection molding step, it is relatively easy to maintain a desired position of several magnetic flux concentrators 20 of the later interface device relative to one another during the first injection molding step. During operation of the later interface device, a magnetic field detected at the at least one magnetic flux concentrator 20 can therefore be reliably evaluated to determine a current flowing through the associated busbar 22 and causing the magnetic field. The manufacturing method described here thus ensures that the at least one magnetic flux concentrator 20 of the interface device produced thereby is well suited as a sensor element for reliable and precise current measurement during its operation.

[0030] Fig. 2B shows the intermediate product after the first injection molding step. It can be seen that the intermediate product formed from the at least one magnetic flux concentrator 20 and the solidified first molding compound 24 can have a shape in which an intermediate plane of symmetry 26 can be defined between two adjacent magnetic flux concentrators 20, which divides the intermediate product into subregions such that each two adjacent subregions are mirror-symmetrical with respect to the intermediate plane of symmetry 26.

[0031] The at least one busbar 22 is only added to the intermediate product after the first injection molding step has been carried out. However, the addition of the at least one busbar 22 takes place before the second injection molding step. When adding the at least one busbar 22, the outer shape of the intermediate product from the first injection molding step can advantageously be used to advantageously position the at least one busbar 22 by arranging the at least one busbar 22 such that it bears at least partially against at least one outer surface 24a formed from the solidified first molding compound 24 (see Fig. 2B and Fig. 2D). For clarity, the at least one outer surface 24a formed from the solidified first molding compound 24, with which the at least one busbar 22 is brought into mechanical contact, is hereinafter referred to as the rail contact surface 24a.In particular, the at least one busbar 22 can be arranged on the intermediate product of the first injection molding step in such a way that the at least one magnetic flux concentrator 20 at least partially frames a section of the busbar 22 assigned to it.

[0032] Preferably, the at least one busbar 22 is fastened / fixed to at least one rail contact surface 24a, which mechanically contacts the respective busbar at least in sections. As can be seen in Fig. 2D, for example, a fastening structure 28 formed from the solidified first molding compound 24 can be formed on and / or adjacent to the respective rail contact surface 24a. By way of example only, in the embodiment described here, a fastening tab 28 is formed from the solidified first molding compound 24 as the at least one fastening structure 28, which partially spans the respectively assigned rail contact surface 24a in such a way that the respectively assigned busbar 22 can be fastened / fixed between the rail contact surface 24a and the adjacent fastening tab 28.Alternatively or additionally, the at least one busbar 22 can also be glued to the respective associated busbar contact surface 24a. Optionally, the at least one busbar contact surface 24 can also be formed with a recess 30 into which the respective section of the associated busbar 22 can be inserted (see Fig. 2B and Fig. 2D).

[0033] During the second injection molding step illustrated in Fig. 2E, the at least one magnetic flux concentrator 20, which is at least partially surrounded by the solidified first molding compound 24, and the at least one busbar 22 are at least partially over-molded with a second molding compound 32. The second molding compound 32 can be of the first molding compound type of the first molding compound 24 or of a second / different molding compound type. For example, plastic can be used as the second molding compound 32. The second injection molding step can also be an injection molding step. The over-mold coating is carried out during the second injection molding step such that at least the solidified first molding compound 24 and the at least one busbar 22 are at least partially covered with the second molding compound 32, which mechanically contacts the solidified first molding compound 24 and the at least one busbar 22.

[0034] If desired, the at least one busbar 22 can be only partially covered with the second molding compound 32 during the second injection molding step, such that at least one partial surface of the at least one busbar 22 is uncovered by the solidified second molding compound 32 after the second injection molding step. This facilitates subsequent electrical contacting / connection of the at least one busbar 22 of the finished interface device.

[0035] It is expressly pointed out that due to the advantageous usability of the solidified first molding compound 24, or its at least one rail contact surface 24a, for positioning the at least one busbar 22 relative to the at least one magnetic flux concentrator 20 during the second injection molding step, no plug-in element, such as a coreback pin, is required. Even if a comparatively high pressure occurs in the second molding compound 32 during the second injection molding step, a reliable hold of the at least one busbar 22 can be ensured by fastening / fixing the at least one busbar 22 to the respectively assigned rail contact surface 24a. Therefore, even a relatively high pressure in the second molding compound 32 cannot trigger any undesired movements of the at least one busbar 22 during the second injection molding step.As already explained above, the advantageous fastening / fixing of the at least one busbar 22 to the respectively associated rail contact surface 24a can be easily realized by means of the at least one fastening structure 28 such that an undesired movement of the at least one busbar 22 during the second injection molding step is prevented.

[0036] Optionally, at least one further component 34 of the later interface device, such as at least one bushing 34 (see Fig. 2C), can be at least partially overmolded with the second molding compound 32 during the second injection molding step together with the at least one magnetic flux concentrator 20 at least partially surrounded by the solidified first molding compound 24 and the at least one busbar 22.It is expressly pointed out that even when the at least one further component 34 is also overmolded with the second molding compound 32, the desired distances between the at least one busbar 22, the at least one magnetic flux concentrator 20 and the at least one further component 34 can be reliably maintained in such a way that the occurrence of sparks is reliably prevented during later operation of the finished interface device. If the at least one socket 34 is also overmolded when the second injection molding step is carried out, an internal volume framed by the at least one socket 34 is preferably kept free of the second molding compound 32 during the second injection molding step.

[0037] The advantageous execution of the first injection molding step first and later (i.e., after the first injection molding step) of the second injection molding step also enables a homogeneous distribution of the molding compounds 24 and 32 used. Therefore, a reliably effective insulation of the subsequent interface device can be formed from the molding compounds 24 and 32. Even if a comparatively high internal stress occurs in the insulation of the subsequent interface device during operation, the homogeneous distribution of the molding compounds 24 and 32 ensures that (essentially) no deformations occur in the insulation. Therefore, the insulation formed from the molding compounds 24 and 32 also exhibits good insulating properties.

[0038] Since no plug-in element, such as a coreback pin, is required during the second injection molding step to hold the individual parts of the future interface device together, plug-in element removal is also not necessary afterward. Accordingly, there is no need to fill at least one hole remaining after plug-in element removal (at the location of a removed plug-in element) with a filler material. This further improves the insulating properties of the insulation formed from the molding compounds 24 and 32. Furthermore, the labor and cost of filling the at least one remaining hole with the filler material are eliminated.

[0039] Fig. 2F shows the finished interface device, with the second molding compound 32 depicted as a "transparent compound" for clarity. In the embodiment described here, the finished interface device is an interface, specifically an AC interface, by means of which an inverter can be electrically connected to an electric motor of a vehicle. Using the manufacturing method described above, the desired positions for the busbars 22 of the finished interface device can be reliably maintained such that the finished interface device is well suited for electrically connecting the inverter to the electric motor via the interface device.

[0040] The fact that the interface device of Fig. 2F is manufactured using the manufacturing method described above can be seen in the fact that its at least one busbar 22 and its at least one magnetic flux concentrator 20 are not only each at least partially surrounded by at least one molding compound 24 and 32, but that the at least one molding compound 24 and 32 comprises both a first molding compound 24 of a first molding compound type and a second molding compound 32 of the first molding compound type or a second molding compound type. Furthermore, the at least one magnetic flux concentrator 20 is at least partially covered with the first molding compound 24 that mechanically contacts the at least one magnetic flux concentrator 20, while the at least one busbar 22 rests at least partially against at least one outer surface 24a formed from the solidified first molding compound 24.Furthermore, at least the solidified first molding compound 24, which at least partially covers the at least one magnetic flux concentrator 20, and the at least one busbar 22 are at least partially covered with the second molding compound 32, which mechanically contacts the solidified first molding compound 24 and the at least one busbar 22. The advantageous properties of the interface device are also ensured in an electric motor for a vehicle equipped therewith and in an electric axle for a vehicle equipped therewith.

[0041] 3A and 3B show representations of intermediate and final products for explaining a second embodiment of the manufacturing method for an interface device for an electric motor or an electric axle of a vehicle.

[0042] In the embodiment described here, the at least one magnetic flux concentrator 20 is completely covered with the first molding compound 24 and / or the second molding compound 32 during the first injection molding step and / or during the second injection molding step. By completely covering the at least one magnetic flux concentrator 20 with the first molding compound 24 and / or the second molding compound 32, it can be ensured that even a magnetic steel, which is highly susceptible to corrosion, can be used without problems as a material for the at least one magnetic flux concentrator 20. The embodiment of the manufacturing method described here thus expands the materials suitable for use for the at least one magnetic flux concentrator 20.

[0043] For example, as can be seen in Fig. 3A based on the intermediate product present immediately before the second injection molding step is carried out, the at least one magnetic flux concentrator 20 can be only partially covered with the first molding compound 24 during the first injection molding step in such a way that at least one part 20a of the at least one magnetic flux concentrator 20 protrudes from the solidified first molding compound 24 after the first injection molding step.

[0044] During the second injection molding step, at least one part 20a of the at least one magnetic flux concentrator 20 protruding from the solidified first molding compound 24 can then be covered with the second molding compound 32. As can be seen from the finished interface device in Fig. 3B, the at least one magnetic flux concentrator 20 is thus completely covered with the first molding compound 24 and / or the second molding compound 32.

[0045] With regard to further method steps of the embodiment described here and additional features of the interface device produced in this way, as well as their advantages, reference is made to the description of Figs. 2A to 2F.

Claims

Claims 1 . Manufacturing method for an interface device for an electric motor or an electric axle of a vehicle, wherein at least one busbar (22) of the later interface device and at least one magnetic flux concentrator (20) arranged on the associated busbar (22) of the later interface device are each at least partially overmolded in at least one injection molding step, characterized by the steps carried out as the at least one injection molding step: Overmolding the at least one magnetic flux concentrator (20) at least partially with a first molding compound (24) of a first molding compound type during a first injection molding step such that the at least one magnetic flux concentrator (20) is at least partially covered with the first molding compound (24) mechanically contacting the at least one magnetic flux concentrator (20); and Overmolding the at least one magnetic flux concentrator (20) which is at least partially surrounded by the solidified first molding compound (24) and the at least one busbar (22), which each bears at least partially against at least one outer surface (24a) which is formed from the solidified first molding compound (24), at least partially with a second molding compound (32) of the first molding compound type or a second molding compound type during a second injection molding step such that at least the solidified first molding compound (24) and the at least one busbar (22) are at least partially covered with the second molding compound (32), which mechanically contacts the solidified first molding compound (24) and the at least one busbar (22).

2. Manufacturing method according to claim 1, wherein the at least one magnetic flux concentrator (20) is completely covered with the first molding compound (24) and / or the second molding compound (32) during the first injection molding step and / or during the second injection molding step.

3. Manufacturing method according to claim 2, wherein the at least one magnetic flux concentrator (20) is only partially covered with the first molding compound (24) during the first injection molding step in such a way that at least one part (20a) of the at least one magnetic flux concentrator (20) protrudes from the solidified first molding compound (24) after the first injection molding step, and at least the one part (20a) of the at least one magnetic flux concentrator (20) protruding from the solidified first molding compound (24) is covered with the second molding compound (32) during the second injection molding step.

4. Manufacturing method according to one of the preceding claims, wherein the at least one busbar (22) is fastened after the first injection molding step and before the second injection molding step in each case to at least one outer surface (24a) which is formed from the solidified first molding compound (24) and which mechanically contacts the respective busbar (22) at least in sections.

5. Manufacturing method according to one of the preceding claims, wherein the at least one busbar (22) during the second injection molding step, it is only partially covered with the second molding compound (32) in such a way that at least one partial surface of the at least one busbar (22) is uncovered by the solidified second molding compound (32) after the second injection molding step.

6. Manufacturing method according to one of the preceding claims, wherein at least one bushing (34) of the later interface device is at least partially over-molded with the second molding compound (32) during the second injection molding step together with the at least one magnetic flux concentrator (20) at least partially surrounded by the solidified first molding compound (24) and the at least one busbar (22).

7. Manufacturing method according to claim 6, wherein each bushing inner volume framed by the at least one bushing (34) is kept free of the second molding compound (32) during the second injection molding step.

8. An interface device for an electric motor or an electric axle of a vehicle, comprising: at least one busbar (22); and at least one magnetic flux concentrator (20), which is arranged on the respective associated busbar (22); wherein the at least one busbar (22) and the at least one magnetic flux concentrator (20) are each at least partially surrounded by at least one molding compound (24, 32), characterized in that, the at least one molding compound (24, 32) comprises a first molding compound (24) of a first molding compound type and a second molding compound (32) of the first molding compound type or a second molding compound type; the at least one magnetic flux concentrator (20) is at least partially covered with the first molding compound (24) that mechanically contacts the at least one magnetic flux concentrator (20); and at least the solidified first molding compound (24) that at least partially covers the at least one magnetic flux concentrator (20) and the at least one busbar (22), which each bears at least partially against at least one outer surface (24a) formed from the solidified first molding compound (24), are at least partially covered with the second molding compound (32), which mechanically contacts the solidified first molding compound (24) and the at least one busbar (32).

9. Interface device according to claim 8, wherein the at least one magnetic flux concentrator (20) is completely covered with the first molding compound (24) and / or the second molding compound (32).

10. An electric motor for a vehicle comprising: an interface device according to claim 8 or 9.

11. An electric axle for a vehicle comprising: an interface device according to claim 8 or 9.

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