Inductive component

Abstract

The invention relates to an inductive component (1) comprising a preferably metallic coil carrier (10) and at least one coil winding (30) arranged on the coil carrier (10) and having a winding axis X. It also comprises a magnetic core stack (20) located at least partially within the coil carrier (10) and comprising two or more spaced-apart magnetic core parts (21, 22). These are arranged around a gap (23) having a width B and at least approximately orthogonal to the winding axis X.The metallic coil carrier (10) is at least partially slotted in the region of the gap(s) (23) of the magnetic core stack (20), said slots (12) running at least approximately parallel to the gap(s) (23) of the magnetic core stack (20) and being wider than the gap(s) (23) of the magnetic core stack (20), such that in a plan view of the coil carrier (10), a gap (23) of the magnetic core stack (20) lies within a slot (12) of the coil carrier (10).

Description

[0001] The invention relates to an inductive component according to the features of the preamble of claim 1.

[0002] Inductors, or inductive components with a magnetic circuit consisting primarily of a magnetic core material and a coil wound around a portion of the core material, are well known throughout electrical engineering. The magnetic circuit often has one or more gaps to adjust the required inductance of the inductive component or to store the required magnetic energy of the inductive component.

[0003] An inductive component is known, for example, from the applicant's German patent DE 10 2013 208 058 B4. The inductive component, which can be a magnetically biased choke, has at least one coil winding. The coil winding has a winding axis. A magnetic core stack is arranged within the coil winding. This magnetic core stack consists of several magnetic core parts, so-called magnetic pills, spaced apart by a gap. The gaps are aligned at least approximately orthogonal to the winding axis of the coil winding.

[0004] Another example of an inductive component with a magnetic circuit with multiple gaps in which insulators are inserted is disclosed in the applicant's European patent EP 1 501 106 B1. Such inductive components are used, for example, as voltage regulators in the form of so-called buck converters or boost converters.

[0005] An example of a boost converter is given in the introduction to the description of DE 198 16 485 A1 and the Figure 1 revealed.

[0006] It is therefore known to introduce one or more air gaps to prevent saturation phenomena in the magnetic circuit of inductive components. An air gap can also be understood as a gap into which an insulator is inserted. Such an air gap, for example in the case of ferrite as the core material, results in a linearization of the component behavior with regard to inductance as a function of the current, but at the same time leads to a number of problems. The cause is the magnetic stray fields, which extend further and further into the outer space around the magnetic circuit and even the inductive component as the air gap size increases. To avoid this, the air gap or gap filled with insulator material is arranged within the coil winding to prevent electromagnetic interactions with electronic components in the vicinity.

[0007] WO 2012 / 016586 A1 describes a magnetic core stack consisting of several soft magnet segments and permanent magnet segments. The magnetic stack has a stacking direction located between two yokes of the magnetic circuit. This inductive component is a fault current limiter.

[0008] It has become increasingly difficult to meet the requirements for inductive components, which require ever-increasing electrical power while simultaneously reducing installation space and the associated need to ensure effective dissipation of power losses from the inductive component. Conventional approaches to the development of inductive components, particularly in the high-power range, are reaching their limits in terms of efficiency, power density, and thermal properties. In particular, power loss dissipation and the minimization of eddy currents in cooling structures pose challenges that must be considered in the development of such inductive components.

[0009] Despite considerable progress in the development of inductive components, especially in the high-power range, there is still a need for improved solutions that provide more efficient power dissipation, better control of magnetic properties and reduction of eddy current losses.

[0010] It is therefore a technical problem underlying the present invention to provide an inductive component that at least partially overcomes the disadvantages of known systems.

[0011] The aim of the present invention is therefore to provide an inductive component which has improved performance by enabling an optimized arrangement and structure of the magnetic core parts and the coil carrier.

[0012] This object is achieved by an inductive component having the features of patent claim 1.

[0013] Further developments of this invention are the subject of the subclaims, which refer back to claim 1.

[0014] The special feature of the present invention is that the inductive component has a coil carrier on which at least one coil winding is arranged, wherein the coil winding has a winding axis X. A magnetic core stack consisting of two or more spaced-apart magnetic core parts is located at least partially within the coil carrier. These magnetic core parts are each arranged around a gap with a specific width and substantially or at least approximately orthogonal to the winding axis. The coil carrier is at least partially slotted in the region of the gaps in the magnetic core stack, wherein these slots run at least approximately parallel to the gaps in the magnetic core stack, but are wider than these gaps. In a plan view of the coil carrier, a gap in the magnetic core stack lies within a slot in the coil carrier.

[0015] One advantage of this configuration is improved electromagnetic decoupling between the air gaps and the resulting cantilevered fields with the coil former, which increases the performance of the inductive component. Another advantage is a reduction in eddy current losses in the coil former, which leads to improved component performance. Since the coil former is preferably made of metal, particularly copper or aluminum, this also ensures improved heat dissipation from the interior of the inductive component.

[0016] In one embodiment of the invention, the coil carrier can be U-shaped, at least approximately U-shaped, or at least approximately rectangular in cross-section. It is also within the scope of the present invention for the coil carrier to be circular or oval in cross-section.

[0017] The coil former is preferably made of a material with good heat conductivity, in particular copper or aluminum, and is bent or kinked as a sheet metal part to give it its shape. Alternatively, the slotted coil former can be formed by casting or by cutting it out, e.g., milling. Regardless of how it is manufactured, the coil former houses a magnetic core stack consisting of one or more magnetic core elements. A coil winding is wound around the outer circumferential surface of the coil former. The winding material of such a coil winding, in particular wire, tape, or HF stranded wire, is insulated to prevent short circuits.

[0018] In one embodiment of the invention, two coil carriers are provided which are identically designed and are mirror images of each other. One coil carrier has a U-shaped sheet metal part at its front end and a similarly bent U-shaped sheet metal part at its other end. Between these two sheet metal parts are one or more U-shaped sheet metal parts, with all the sheet metal parts of this coil carrier being spaced apart from one another by a gap of width C. In a special embodiment of this coil carrier, a sheet metal part angled at 90° can be integrally formed on the free ends of the U-shaped parts. Viewed in section, the coil carrier is then almost rectangular in shape, with the opposing sheet metal parts not touching but aligned in a plane with a distance from one another. The coil carrier is thus provided with a through-opening on one side.Metal sheet metal parts, especially those made of copper, can be used as sheet metal parts. The coil carrier or parts of the coil carrier can also be made of another material with good thermal conductivity, such as aluminum or aluminum oxide.

[0019] In a further development of the invention, it is advisable to hold the coil carrier parts, which are arranged at a distance from one another by a gap, by an outer part, in particular an outer wall. Such an outer wall is also made of copper, for example, and is attached to one of the main surfaces of the coil carrier in a U-shaped design. This outer wall then bridges the aforementioned slots in the coil carrier. Such outer walls ensure improved mechanical stability of the coil carrier. These outer walls also ensure improved heat dissipation from the interior of the inductive component and are preferably thermally connected to a wall of a housing of the inductive component. For example, these outer walls lie flat and preferably under pressure against a metallic wall of the housing of the inductive component, or are screwed or riveted to the housing wall.Alternatively, instead of plate-shaped outer walls, other outer parts can be provided to hold the coil support parts, which are spaced apart by a gap, together and against each other, similar to a picket fence. For example, outer rods or outer tubes can also be provided here. If these rods or tubes are hollow, cooling fluid can also be channeled through these cavities to contribute to effective heat dissipation of the coil support.

[0020] For improved heat dissipation from the interior of the inductive component, the coil carrier is preferably connected at both outer ends to metal, preferably copper, mounting tabs. These mounting tabs can also be integrally formed onto parts of the coil carrier. These mounting tabs are thermally coupled to a wall of the inductive component's housing, for example, by screwing.

[0021] In a preferred embodiment of the invention, a magnetic core stack is inserted into the slotted coil former, the number of magnetic core stack elements being adapted to the number of parts of the coil former so that a corresponding number of gaps are present between the magnetic core stack elements. However, it can also be provided that the number of air gaps is smaller than the number of slots in the coil former. When using two coil formers with two inserted coil windings aligned parallel to one another, a further development of the invention provides that a magnetic core stack is inserted in each of the two coil formers and that a magnetic core yoke is provided at at least one end of these two magnetic core stacks, preferably at both ends, which magnetically connects the two magnetic core stacks to one another.

[0022] In another development of the invention, the magnetic core yoke or, when two magnetic core yokes are used, at least one, preferably both of the magnetic core yokes, can be U-shaped.

[0023] In one embodiment of the invention, relatively thin sheets of insulating material, particularly aluminum oxide or ceramic, can be inserted between the gaps of the magnetic core parts to create the air gaps. Inserting insulating sheets into the gaps of the magnetic core stack is recommended to ensure a defined width of the gaps of the magnetic core stack. Instead of such insulating sheets, the magnetic core parts can also be glued together within the scope of the present invention. The adhesive layer itself then serves as the air gap.

[0024] It has proven particularly advantageous to select the gap width of the magnetic core stack at least approximately between 1 mm and 3 mm, and to make the slots of the coil former approximately two to five times as large. When viewed vertically from above, the gaps of the magnetic core stack should be located between the slots of the coil former. The gaps should preferably be aligned symmetrically or centrally to the slots of the coil former.

[0025] In a further development of the invention, the individual magnetic core parts of the magnetic core stack can consist, for example, of ferrite or of a nanocrystalline material, an amorphous magnetic material or a powder material.

[0026] The inductive component according to the present invention is explained in more detail in connection with an exemplary embodiment using several figures. They show: Figure 1 an inductive component with two coil carriers, each with a magnetic core stack to be inserted in a perspective exploded view, Figure 2 the coil carriers of Figure 1 with inserted magnetic core stacks, Figure 3 the coil carriers of Figure 2 with inserted magnetic core stacks in plan view from above, Figure 4 an enlarged detail of Figure 3 in the area of ​​the gap of the magnetic core stacks and the slots of the coil carriers, Figure 5 an exploded view of the magnetic core stacks and the coil carriers of Figure 1 with coil windings sitting on the coil carriers, Figure 6 the inductive component of Figure 5 in its installation situation in a housing with a view from above of the opened housing, and Figure 7 a perspective view of the arrangement of Figure 6 .

[0027] In the following figures, the same reference symbols denote the same parts and have the same meaning, unless otherwise stated.

[0028] In Figure 1 An embodiment of an inductive component according to the invention is shown. The inductive component is provided with the reference number 1. For better visibility of the structure of the coil carrier and the magnetic core stack arranged therein, Figure 1 The coil windings have not been shown. However, this will be explained in connection with the later figures.

[0029] The inductive component 1 has a coil support arrangement, which preferably consists of two metallic coil supports 10. Each of these coil supports 10 is provided for receiving a coil winding. The two coil supports 10 are made of a metallic material, preferably copper. The two coil supports 10 are arranged in mirror images of one another and, in the illustrated embodiment, have four coil support parts lying next to one another along a winding axis X of the coil winding (not shown), each of which is bent into a substantially square shape. The four adjacent coil support parts are spaced from one another by a slot 12. Accordingly, there are three slots 12 between each of the four coil support parts.If one considers the left coil support part of the rear coil support 10 facing away from the viewer, this coil support part has a first main surface 10a, a second main surface 10b, a third main surface 10c, and a fourth main surface 10d. The first main surface 10a forms in . Figure 1the bottom of the coil carrier 10. The second main surface 10b extends vertically upwards at a right angle from the first main surface 10a. From this second main surface 10b, the third main surface 10c extends towards the viewer. This third main surface 10c is L-shaped when viewed from above, with another wall section of the coil carrier 10 extending from this L-shaped third main surface 10c back down at a right angle to the first main surface 10a. In the same way, a wall section 10d extends upwards from the first main surface 10a. The upward-facing wall section and the downward-facing wall section form the fourth main surface 10d, but are spaced apart from one another. Adjoining this coil carrier section of the rear coil carrier 10, which is arranged on the left edge of the coil carrier 10, are two coil carrier sections on the right, the upper main surface 10c of which is square or rectangular.To the right of the two middle coil carrier parts there is a fourth coil carrier part, which is designed similarly to the first coil carrier part and has an upper and lower L-shaped main surface.

[0030] The coil carrier 10 facing the viewer is designed in a similar way and is a mirror image of the first coil carrier 10 facing away from the viewer.

[0031] On the outside of the coil supports 10, namely on the respective main surfaces 10b, an outer wall 15, for example a copper plate, is attached, preferably by a soldered connection. This outer wall 15 extends in the direction of the winding axis X over the entire or almost the entire length of the two coil supports 10. As can also be seen from Figure 1As can be clearly seen, L-shaped fastening tabs 17 are formed on the first main surfaces of the edge-side coil support parts, preferably pointing inwards under the coil support 10. Via these fastening tabs 17, which preferably have fastening holes, the coil supports 10 can be mechanically connected to a housing part of the inductive component 1 and fastened there.

[0032] As additionally from Figure 1 As can be seen, the arrangement consisting of two coil carriers 10 has a through-opening 14, whereby two channels running parallel to the winding axis X are formed via the claw-shaped coil carrier parts, into each of which a magnetic core stack can be inserted. It should also be mentioned that the two coil carriers 10, which are arranged as mirror images of each other, are separated from each other by a slot on their left and right coil carrier parts. The two slots are in Figure 1provided with the reference number 11.

[0033] The magnetic core to be inserted into the two coil supports is designed as a double U-shaped core and is designated by reference numeral 20. The magnetic core has a total of four cuboid-shaped magnetic core parts 21. Two of these magnetic core parts 21 are each inserted into a channel of the coil supports 10, with a spacer element 27, preferably made of aluminum oxide or ceramic, interposed between the two magnetic core parts. A spacer element 27 is in turn attached to the free outer sides of the magnetic core parts 21 thus inserted into the two channels of the two coil supports 10. The two magnetic core stacks 20, each with two magnetic core parts 21, are then magnetically connected by a U-shaped magnetic core yoke 25. The magnetic core yokes on the left and right are designated by reference numeral 25.

[0034] The key to the present design of the coil carriers 10 with the slots 12 provided therein and the magnetic core stacks provided with gaps via the spacer elements 27 is the relative arrangement of the slots 12 and the spacer elements 27. This will be discussed later.

[0035] In Figure 2 The arrangement with the two coil supports 10 and the magnetic core placed therein is shown in perspective. As can be seen, the magnetic core yokes 25 are almost flush with the metallic coil supports 10. The magnetic core yokes 25 therefore do not protrude beyond the coil supports 10. Thus, the two coil supports 10 with the inserted magnetic core form a compact structural unit.

[0036] Figure 3 shows the arrangement of Figure 2A vertical top view of the two coil supports 10 with the magnetic core inserted therein. The slots 12 between the individual coil support parts are clearly visible. As explained, there are three slots 12 between each coil support 10. These slots 12 have Figure 4 a distance C. The slots 12 are arranged orthogonally to the winding axis X of the inductive component 1. Magnetic core parts 21 of the magnetic core stack 20 protrude from both sides into the respective slots 12 of the coil carriers 10. As explained, the individual magnetic core parts 21 are also arranged at a distance from one another. This distance is defined by an air gap or by the spacer elements 27 inserted there. The distance is B. This distance B between the individual magnetic core parts 21 is, as the enlarged illustration of Figure 4shows, significantly smaller than the width of the gap 23. While the width of the magnetic core stack and thus the width of the spacer element 27 is at least approximately between about 1 mm and about 3 mm, the slots 12 of the coil carrier and thus the width C of the slots 12 are selected to be approximately two to five times as large. The width of the slots 12 of the coil carrier 10 can therefore preferably be between 2 mm and 15 mm. In this context, it should also be noted - and this will be explained in the Figures 3 and 4 clearly - that the spacer elements 27 are preferably placed centrally to the width C of the slots of the coil carrier 10. It is understood that the spacer elements 27 are also aligned orthogonally to the winding axis X. As can be seen from Figure 3As can also be seen, the outer walls 15 have a thickness D. This thickness D can be made wider than the thickness of the walls of the coil carrier 10. This is advantageous for good power loss dissipation from the interior of the inductive component 1, in particular when the outer walls 15 lie flat against the metallic housing walls of the inductive component 1, for example via the tabs 17 shown.

[0037] Figure 5 shows a similar representation as Figure 1 . In contrast to Figure 1 coil windings 30 are now wound on each of the two coil carriers 10. In addition, Figure 5It is clear that the entire magnetic core 20 consists of a total of six magnetic core parts, four of which are cuboid magnetic core parts 21 and two magnetic core yokes 25 located to the left and right of these magnetic core parts 21. A spacer element 27 is located between the magnetic core parts 21 and the respective magnetic core yoke 25. The open ends 25a, 25b of the two magnetic core yokes 25 have the same rectangular contour as the spacer elements 27 adjacent there or the cuboid magnetic core parts 21 located between the two magnetic core yokes 25.

[0038] Figure 6 shows the inductive component 1 with the two coil carriers 10 and the two coil windings 30 sitting thereon in the installation situation in a preferably metallic housing 60. The metallic housing 60 is approximately rectangular or cuboid-shaped, as the top view in Figure 6 shows. In Figure 7 Finally, the inductive component 10 of Figure 6 shown in a perspective view from the front. For clarity, an upper cover part of the housing 60 has been omitted. List of reference symbols

[0039] 1Inductive component 10Metallic coil carrier 10aMain surface 10bMain surface 10cMain surface 10dMain surface 11Slot 12Slot 14Opening 15Outer wall 17Fastening tab 20Magnet core stack 21Magnet core part 23Gap 25Magnet core yoke 25aEnd 25bEnd 27Spacer element 30Coil winding 60Housing 62Housing inner wall 70Aluminum parts BWidth of the gap 23 CWidth of the slots 12 DThickness of the outer wall 15 XWinding axis

Claims

1. Inductive component (1) with a coil carrier (10) and at least one coil winding (30) arranged on the coil carrier (10), which has a winding axis X, and with a magnetic core stack (20) which is at least partially seated within the coil carrier (10) and which has two or more magnetic core parts (21, 22) spaced apart from one another by a gap 23, wherein the gaps (23) are arranged at least approximately orthogonal to the winding axis X, characterized in thatthe coil carrier (10) is at least partially slotted in the region of at least one of the gaps (23) of the magnetic core stack (20), such that at least one of these slots (12) runs at least approximately parallel to the gap or gaps (23) of the magnetic core stack (20) and is wider than the gaps (23) of the magnetic core stack (20), such that in a plan view of the coil carrier (10) a gap (23) of the magnetic core stack (20) lies within a slot (12) of the coil carrier (10).

2. Inductive component (1) according to claim 1, characterized in that the coil carrier (10) has an opening (14) on one side which extends along the winding axis X over the entire length of the coil carrier (10).

3. Inductive component (1) according to claim 1 or 2, characterized in thatthe coil carrier (10) is U-shaped or at least approximately U-shaped, C-shaped or at least approximately C-shaped or at least approximately square-shaped when viewed in section.

4. Inductive component (1) according to claim 1 or 2, characterized in that the coil carrier (10) is at least approximately rectangular in cross-section.

5. Inductive component (1) according to one of claims 1 to 4, characterized in that the coil carrier (10) is at least partially double-walled on one of its main surfaces (10b), wherein an outer wall (15) belonging to the coil carrier (10) overlaps slots (12) of the coil carrier (10) present there.

6. Inductive component (1) according to claim 5, characterized in that the outer wall (15) has a greater thickness (D) than a thickness of a wall of the coil carrier (10).

7. Inductive component (1) according to claim 5 or 6, characterized in thatthe outer wall (15) is thermally conductively connected, preferably soldered, to a wall (11) of the coil carrier (10).

8. Inductive component (1) according to one of claims 1 to 7, characterized in that two coil windings (30) and two coil carriers (10) are provided and that these are arranged in mirror image to each other.

9. Inductive component (1) according to claim 8, characterized in that a magnetic core stack (20) is inserted into each of the two coil carriers (10) and a magnetic core yoke (25) is provided at at least one end of these two magnetic core stacks (20), preferably at both ends, which magnetically connects the two magnetic core stacks (20) to one another.

10. Inductive component (1) according to claim 9, characterized in that the magnetic core yoke (25) is U-shaped or C-shaped and has two free ends (25a, 25b) which rest on the two magnetic core stacks (20).

11. Inductive component (1) according to one of claims 1 to 10, characterized in that a spacer element (27) made of insulating material, in particular aluminum oxide or ceramic, is arranged between magnetic core parts (21, 22).

12. Inductive component (1) according to one of claims 1 to 11, characterized in that the coil carrier (10) is made of metal, in particular copper or aluminum.

13. Inductive component (1) according to one of claims 1 to 12, characterized in that a width (B) of the gap (23) of the magnetic core stack (20) is at least approximately 1 mm to 3 mm wide and the slots (12) of the coil carrier (10) have a width (C) approximately 2 to 5 times greater.

Images