Device comprising a busbar assembly, a filter device and a cover, associated manufacturing method, as well as a current straightener and drive device

Description

[0001] The present invention relates to a device with a busbar arrangement having two busbars and a filter arrangement comprising a filter device which surrounds the busbars in a filter section and a cover covering the filter device.

[0002] In addition, the invention relates to an associated manufacturing process, a power converter and a drive device.

[0003] Filter devices surrounding the busbars of a busbar assembly typically serve as common-mode chokes to improve electromagnetic compatibility. A filter device is typically the largest and most massive component attached to the busbar assembly. Furthermore, filter devices made of ferrite material exhibit significant manufacturing tolerances that must be taken into account during their placement and mounting on the busbar assembly.

[0004] Document US 2018 / 090257 A1 discloses a busbar unit and a method for its manufacture. This unit is a structure in which several parallel busbars are guided through a magnetic core surrounded by an insulating material. The core serves to reduce electromagnetic interference. The busbars are separated from each other within the core by insulating partitions. The object of the invention is to simplify the manufacture of the unit and reduce its size by assembling the core and the busbars separately. Key features include the integration of a magnetic core, the electrical insulation of the busbars, and methods for a stable connection between the components.

[0005] However, manufacturing such a busbar unit requires complex molds and processes, especially when the magnetic core and busbars are joined in one piece. This leads to increased production effort and costs.

[0006] Document US 2017 / 149348 A1 describes a noise-filtering device that also integrates a busbar around a magnetic core. The magnetic core, which reduces electromagnetic noise, is attached to the busbar by a fixing device. This fixing device ensures the mechanical stability of the core and facilitates easy assembly and disassembly. The magnetic core can be designed in various shapes, such as oval or polygonal.

[0007] However, the described fixing device for the magnetic core does not offer any optimization possibilities for alternative arrangements of the filter device or adaptations to different busbar configurations.

[0008] Document DE 10 2015 205 815 A1 discloses a common-mode choke device for an electric / electric hybrid vehicle, which is associated with two electrical conductors of a supply line between a vehicle battery and an inverter. The common-mode choke device comprises a fixing device and a two-part common-mode choke, which includes two choke sections, each of which has a recess in a contact surface for the positive-locking reception of a section of the current-carrying conductor. The choke sections are joined by connecting their contact surfaces to form a unit enclosing the electrical conductors. The fixing device is a housing with a first and a second housing part, which can be snapped together. The fixing device also includes spring elements for fixing the common-mode choke inside the housing.The common-mode filter device is positively fitted into a recess in a housing of the inverter, which can be closed with a cover.

[0009] However, such a fastening method is disadvantageous because the positively fitted common-mode filter assembly exerts undesirable mechanical loads on the cover. Furthermore, the spring elements cause abrasion of the common-mode filter, which can accumulate in the inverter housing and lead to malfunctions.

[0010] The invention is based on the objective of providing an improved possibility for arranging a filter device on a busbar arrangement.

[0011] To solve this problem, a device as defined in claim 1 is proposed.

[0012] The invention is based on the concept of enabling a positive-locking connection between the cover and the busbar assembly to fix the filter device to the busbar assembly. The cover itself is positioned on the busbar assembly by the fixing device and does not merely serve to enclose the filter device, as is conventionally provided. In this way, movement of the cover and the filter device in one direction is restricted when the fixing device is in contact with the busbar assembly. A conventionally provided cover, which restricts this movement and must bear a mechanical load, can thus be advantageously omitted.

[0013] The busbars typically run parallel along the filter section. Regarding the filter device, it is advantageous for it to be made of a ferrite material. Typically, the filter device consists of two E-shaped bodies whose outer legs are attached to each other. An adhesive layer may be provided between each leg for fastening.

[0014] The fixing device has several fixing elements which are elastically deformable when the cover is placed on top, allowing it to snap into place behind the busbar assembly. Such a cover can be easily manufactured, for example as an injection-molded part, and can be attached to the busbar assembly with minimal effort. In particular, the snap connection enables automated assembly of the busbar assembly during the device's production. Typically, each fixing element comprises an elastically deformable leg section and a hook element located at a free end of the leg section, which engages behind the busbar assembly.

[0015] It is also advantageous to provide that the busbar assembly has an electrically insulating web at each end of the filter section, behind which the fixing device engages. Particularly preferably, the fixing device engages the webs from a side facing away from the filter assembly. This also prevents movement of the filter assembly along the direction of the busbars.

[0016] It can be provided that the busbars each have long sides and short sides in cross-section, with the web extending perpendicular to one of the inner long sides of the busbars. The web is therefore expediently arranged between the busbars.

[0017] Alternatively or additionally, it can be provided that the bridge has long sides and short sides in cross-section, with the short sides extending along one direction from one end of the filter section to the other end of the filter section.

[0018] In principle, the device according to the invention can be provided that the busbar arrangement has an electrically insulating sheathing surrounding the busbars, at least along the filter section. The sheathing can also extend over further areas of the busbars and, in particular, have one or more recesses that expose the busbars.

[0019] It is particularly advantageous if the bridge and the casing are formed in one piece and / or from a single material. This allows the bridges to be formed without special effort during overmolding of the busbars to implement the conversion.

[0020] The device according to the invention particularly includes a base element to which the busbar assembly is attached. The base element can, for example, be part of a housing that accommodates the busbar assembly and the filter device. Preferably, the casing has fastening elements by which the busbar assembly can be attached to the base element. The fastening elements can, for example, be projections of the casing in which a through-opening, and in particular a press-fit bushing arranged therein, is formed. In this respect, the device can also have a fastening means for each fastening element by which the fastening element is attached to the base element. In the simplest case, the fastening means can be designed as a screw passing through the through-opening.

[0021] To fix the fixing device in a position resting on the busbar assembly, the filter assembly can be provided with a first restoring element located between the base element and the cover, which exerts a restoring force on the cover, pressing the fixing device against the busbar assembly. This effectively suppresses movement of the cover in the direction perpendicular to the base element.

[0022] Particularly preferred are a coefficient of static friction of a cover-side surface of the first restoring element with respect to the cover material and a coefficient of static friction of a base-element-side surface of the first restoring element with respect to the base element material that is greater than the coefficient of static friction with respect to both the cover material and the base element material. This prevents the cover from slipping on the base element.

[0023] The filter arrangement can advantageously include a second restoring element between the base element and a cover surface, wherein the second restoring element exerts a restoring force on the filter device. The second restoring element thus prevents relative movement of the filter device with respect to the cover in the direction perpendicular to the base element. It is preferred that the second restoring element is provided between the base element and the filter device. However, it is also conceivable, alternatively, that the second restoring element is provided between the filter device and the cover surface.

[0024] Regarding the second restoring element, it is also preferred if the coefficient of static friction of a filter-side surface of the second restoring element with respect to the filter material and the coefficient of static friction of a bottom-element or lid-side surface of the second restoring element with respect to the bottom-element or lid material are greater than the coefficient of static friction with respect to both the filter material and the bottom-element or lid material. This prevents the filter device from slipping relative to the bottom-element or lid.

[0025] Particularly preferably, the first restoring means and the second restoring means are formed by a one-piece restoring element which is arranged between the filter device and the cover on the one hand and the base element on the other.

[0026] It is particularly advantageous to provide that the first restoring means and / or the second restoring means and / or the restoring element is / are designed as a flat molded body. The molded body forming the second restoring means or the restoring element is preferably plate-like.

[0027] Furthermore, the first restoring element and / or the second restoring element and / or the restoring element can be made of a foamed material. Such a restoring element or restoring element, compared to spring elements resting on the filter device as known in the prior art, prevents abrasion of the filter device material.

[0028] The device according to the invention can, of course, also include one or more further filter sections, with a further filter arrangement being provided for each further filter section. All embodiments relating to the first filter arrangement described above can be transferred to the further filter arrangement(s).

[0029] Furthermore, the problem underlying the invention is solved by a manufacturing process comprising the following steps: providing a busbar assembly with two busbars; attaching a filter device in a filter section of the busbar assembly so that the filter device surrounds the busbars; providing a cover for the filter device; and fixing the cover to the busbar assembly such that a fixing device for the cover engages behind the busbar assembly. All embodiments of the device according to the invention can be transferred to the manufacturing process according to the invention; in particular, the previously described components of the device can be used within the framework of the manufacturing process.

[0030] The method according to the invention can further comprise the following step: providing two E-shaped bodies, in particular made of a ferrite material. The bodies can be glued to the busbar assembly from opposite sides and to their outer legs for attaching the filter device.

[0031] Furthermore, a base element can be provided. Additionally, a first and / or a second restoring device can be provided. The restoring device(s) can be arranged on the base element. Furthermore, the busbar assembly can be arranged on the base element such that the filter device rests on the second restoring device. The busbar assembly can be attached to the base element.

[0032] Preferably, the cover's fixing elements deform elastically during fixing and engage behind the busbar assembly by snapping into place. Furthermore, the cover can elastically deform the first restoring element, causing it to exert a restoring force on the cover. Similarly, when the cover is fixed, the second restoring element can be elastically deformed and exert a restoring force on the filter device.

[0033] The problem underlying the invention is also solved by a power converter comprising the device according to the invention or a device obtained by the manufacturing process according to the invention, wherein the busbars are electrically connected to a power unit of the power converter.

[0034] In addition, the problem underlying the invention is solved by a drive device for propelling a vehicle, comprising a current converter according to the invention and an electrical machine that can be supplied by the current converter.

[0035] All descriptions of the device according to the invention can be applied analogously to the power converter and the drive device according to the invention, so that the aforementioned advantages can also be achieved with these.

[0036] Further advantages and details of the present invention will become apparent from the exemplary embodiments described below and from the drawings. These are schematic representations and show: Fig. 1 a perspective sectional view of an embodiment of the device according to the invention; Fig. 2 a perspective sectional view of the in Fig. 1 The device shown is located in a filter section of a busbar assembly; Fig. 3 is a top view of the busbar assembly of the device shown in Fig. 3. Fig. 1 device shown; Fig. 4 a schematic diagram of a filter device of the type shown in Fig. 1 The device shown; and Fig. 5 a schematic diagram of an embodiment of the drive device according to the invention with an embodiment of the power converter according to the invention in a vehicle.

[0037] Fig. 1 is a perspective sectional view of an embodiment of a device 1.

[0038] The device 1 comprises a busbar assembly 2 with two busbars 3, 4 and a filter assembly 5. The filter assembly 5 comprises a filter device 7 arranged in a filter section 6 of the busbar assembly and a cover 8 which covers the filter device 7. The filter assembly 5 also comprises a return element 9.

[0039] Furthermore, in the present embodiment, the device 1 comprises a further filter arrangement 5a for a further filter section 6a of the busbar arrangement 2. The filter arrangements 5 and 5a are identical, so that all descriptions of the filter arrangement 5 can be applied to the further filter arrangement 5a.

[0040] The device 1 also includes a base element 10 to which fastening elements 11 of the busbar arrangement 2 are attached by fastening means (not shown), for example screws, wherein in Fig. 1 Only one fastening element 11 is visible. The filter arrangements 5, 5a lie in trough-like sections of the base element 10 on it.

[0041] Fig. 2 This is another perspective sectional view of the device 1 in filter section 6 of the busbar arrangement 2. The section plane of Fig. 2 runs parallel to that in Fig. 1 between busbars 3 and 4.

[0042] The cover 8 comprises a fixing device with two fixing elements 12, 13 and is designed to engage behind the busbar assembly 2 for fastening the cover to it. The fixing elements 12, 13 each have an elastically deformable leg section 14 and, at a free end of the leg section 14, a hook element 15 that engages behind the busbar assembly.

[0043] The busbar assembly 2 comprises an electrically insulating sheath 16 that completely surrounds the busbars 3, 4 in the filter section 6, and at both ends of the filter section 6, a web 17, 18 of the busbar assembly 2, formed integrally with the sheath and made of the same material. The fixing device or fixing elements 13, 14 engage the webs 17, 18 from a side facing away from the filter device 7. The leg sections 14 are elastically deformed outwards until the hook element 15 reaches a bottom-element end of the web 17, 18 and snaps the web 17, 18 into place.

[0044] The webs 17, 18 extend between the conductor rails 3, 4 perpendicular to their inner long sides. The webs 17, 18 themselves have a substantially rectangular cross-section, with the short sides extending along one direction from one end of the filter section 6 to its other end.

[0045] The restoring element 9 is formed as a flat, plate-like molded body made of a foamed material and provides restoring forces in the event of elastic deformation.

[0046] The return element 9 functions as a first return means, exerting a return force on the cover 8 that presses the fixing device against the busbar assembly 2. As in Fig. 1 As can be seen, a bottom-element-side edge of the cover 8, opposite a cover surface 19 of the cover 8, rests on the restoring element 9 and deforms it elastically. The first restoring element can therefore be considered to be an outer edge region of the restoring element 9. The first restoring element secures the cover 8 to the busbar assembly 2 in a force-fit manner in a z-direction.

[0047] The restoring element 9 also functions as a second restoring element between the base element 10 and the filter device 7, exerting a restoring force on the filter device 7. For this purpose, the filter device 7 rests on the restoring element 9 and deforms it elastically. An inner area of ​​the restoring element 9, surrounded by the outer edge region that constitutes the first restoring element, can thus be considered the second restoring element. The second restoring element presses the filter device 7 against the cover surface 19 of the cover 8, so that a force-fit fixing of the filter device 7 to the busbar assembly 2 in the z-direction is achieved via the cover surface 19.

[0048] The restoring element 9, or the restoring means realized by it, are furthermore designed such that they prevent or inhibit slippage of the filter device 7 and the cover 8 relative to the base element 10. Together with the fixing elements 12, 13 engaging behind the webs 17, 18, this also secures the filter device 7 to the busbar assembly 2 in the x and y directions. To prevent or inhibit slippage, the coefficient of static friction of a cover- and filter-device-side surface of the restoring element 9 with respect to the material of the cover 8 and the filter device 7, respectively, and the coefficient of static friction of a base-element-side surface of the restoring element 9 with respect to the material of the base element 10 are selected to be greater than the coefficients of static friction relative to the material of the cover 8 and the filter device 7 relative to the material of the base element 10.

[0049] Fig. 3 Figure 2 is a top view of the busbar arrangement 2 and shows in particular the positions of the filter sections 6, 6a and the webs 17, 18 formed at their ends. It can be seen that the sheathing 16 is continuous in the filter sections 6, 6a, whereas outside the filter sections 6, 6a the sheathing 16 has some recesses exposing the busbars 3, 4. Fig. 3 The figure also shows the position of a total of three fastening elements 11, which are formed as projections on the casing 16 and each have a through-opening 11a and a press-fit bushing 11b arranged therein and integrated into the casing 16 with a thread for passing the fastening element (not shown).

[0050] Fig. 4 Figure 1 is a schematic diagram of the filter device 7. This device consists of two E-shaped bodies 20 made of a ferrite material. The outer legs 21 of the bodies are attached to each other in pairs by adhesive layers 22.

[0051] Fig. 5 is a schematic diagram of an embodiment of a drive device 23 with an embodiment of a power converter 24.

[0052] The power converter 24 has a device 1 according to the previously described embodiment, wherein the busbars 3, 4 provide an electrically conductive connection between a battery 25 and a power unit (not shown) of the power converter 23. The base element 10 forms a housing section of the power converter 24. The drive unit 23 further comprises an electric machine 26 for driving a vehicle 27, which is electrically supplied by the power converter 24.

[0053] According to an embodiment of a manufacturing method for a device 1, a busbar assembly 2 with two busbars 3, 4 is first provided. Next, two E-shaped bodies made of a ferrite material are provided and placed on the busbar assembly 2 from opposite sides for mounting a filter device 7, and glued at their outer legs. A base element 10 and a return element 9 are then provided, with the return element 9 being arranged on the base element 10. The busbar assembly 2 is then positioned on the base element 10 such that the filter device 7 rests on the return element 9, and is attached to the base element 10. Finally, a cover 8 for the filter device 7 is provided and fixed to the busbar assembly 2 such that a fixing device for the cover engages behind the busbar assembly 2.In this process, the fixing elements 12, 13 of the cover deform elastically and engage the webs 17, 18 of the busbar assembly 2 by snapping into place. Furthermore, the cover 8 elastically deforms the restoring element 9, so that the latter exerts a restoring force on the cover 8.

[0054] Furthermore, all statements regarding the exemplary embodiments of device 1 can be applied to the manufacturing process.

Claims

1. Apparatus (1), comprising: - a busbar arrangement (2) having two busbars (3, 4), and - a filter arrangement (5), comprising a filter device (7) which surrounds the busbars (3, 4) in a filter section (6), and a cover (8) covering the filter device (7), wherein the cover has a fixing device which is configured to engage behind the busbar arrangement (2) for fastening the cover (8) to the busbar arrangement (2), characterized in that the fixing device has a plurality of fixing elements (12, 13) which are elastically deformable when the cover is placed on, in order to engage behind the busbar arrangement (2) by snapping.

2. Apparatus according to Claim 1, wherein the busbar arrangement (2) has at both ends of the filter section (6) a respective electrically insulating web (17, 18), which the fixing device engages behind.

3. Apparatus according to Claim 2, wherein the busbars (3, 4) each have, in cross-section, long sides and short sides, wherein the web (17, 18) extends perpendicularly to a respective inner long side of the busbars (3, 4), and / or wherein the web (17, 18) has, in cross-section, long sides and short sides, wherein the short sides extend along a direction from one end of the filter section (6) to the other end of the filter section (6).

4. Apparatus according to Claim 2 or 3, wherein the busbar arrangement (2) has, at least along the filter section, an electrically insulating sheath (16) surrounding the busbars (3, 4), wherein the web (17, 18) and the sheath (16) are formed in one piece and / or of the same material.

5. Apparatus according to one of the preceding claims, further comprising a base element (10) to which the busbar arrangement (2) is fastened.

6. Apparatus according to Claim 5, wherein the filter arrangement (5) has a first resilient means arranged between the base element (10) and the cover (8), which exerts a restoring force on the cover (8), pressing the fixing device against the busbar arrangement (2).

7. Apparatus according to Claim 6, wherein a coefficient of static friction of a cover-side surface of the first resilient means with respect to the material of the cover (8) and a coefficient of static friction of a base-element-side surface of the first resilient means with respect to the material of the base element (10) are greater than a coefficient of static friction with respect to the material of the cover (8) and the material of the base element (10).

8. Apparatus according to one of Claims 5 to 7, wherein the filter arrangement has a second resilient means between the base element (10) and a top surface (19) of the cover (8), wherein the second resilient means exerts a restoring force on the filter device (7).

9. Apparatus according to Claim 8, wherein a coefficient of static friction of a filter-device-side surface of the second resilient means with respect to the material of the filter device (7) and a coefficient of static friction of a base-element-side or top-surface-side surface of the second resilient means with respect to the material of the base element (10) or the top surface (19) are greater than a coefficient of static friction with respect to the material of the filter device (7) and the material of the base element (10) or the top surface (19).

10. Apparatus according to Claims 6 or 7 and Claims 8 or 9, wherein the first resilient means and the second resilient means are formed by a one-piece resilient element (9) which is arranged between the filter device (7) and the cover (8) on the one hand and the base element (10) on the other hand.

11. Apparatus according to one of Claims 6 to 10, wherein the first resilient means and / or the second resilient means and / or the resilient element is or are designed as a flat shaped body, and / or the first resilient means and / or the second resilient means and / or the resilient element is or are formed from a foamed material.

12. Method of manufacturing, comprising the following steps: - Providing a busbar arrangement (2) with two busbars (3, 4); - Attaching a filter device (7) in a filter section (6) of the busbar arrangement (2) such that the filter device (7) surrounds the busbars (3, 4); - Providing a cover (8) for the filter device (7); and - Fixing the cover (8) to the busbar arrangement (2) in such a way that a fixing device of the cover (8) engages behind the busbar arrangement (2).

13. Power converter (24), comprising an apparatus (1) according to one of Claims 1 to 11 or an apparatus (1) obtained by a manufacturing method according to Claim 12, wherein the busbars (3, 4) are electrically conductively connected to a power unit of the power converter (24).

14. Drive device (23) for driving a vehicle (27), comprising a power converter (24) according to Claim 13 and an electric machine (26) that can be supplied by the power converter (24)