INDUCTIVE COMPONENT AND METHOD FOR PRODUCING AN INDUCTIVE COMPONENT
20210280350 · 2021-09-09
Inventors
Cpc classification
H01F2017/048
ELECTRICITY
H01F2017/065
ELECTRICITY
H01F41/0246
ELECTRICITY
H01F17/043
ELECTRICITY
International classification
Abstract
The present invention provides an inductive component (1a) in several illustrative embodiments and a method for producing such an inductive component. The inductive component (1a) comprises a bus bar (4a) and at least one magnetic core (6a) which is formed along a section of the bus bar (4a) and surrounds the bus bar (4a) in that section at least in part, wherein the at least one magnetic core (6a) is formed as a plastic-bonded magnetic core or a core made of magnetic cement.
Claims
1. Inductive component having a bus bar and at least one magnetic core formed along a section of said bus bar; and surrounding said bus bar in said section at least in part, wherein said at least one magnetic core is formed as a plastic-bonded magnetic core or a core made of magnetic cement.
2. Inductive component according to claim 1, wherein exposed end sections of said bus bar are formed as connecting contacts and at least one bus bar section exposed at least in part between said magnetic core and a terminal is further formed for electrically connecting to a capacitor.
3. Inductive component according to claim 1, further comprising a housing in which said bus bar is accommodated at least in part, wherein said magnetic core in said housing is formed as a plastic-bonded magnetic core by plastic injection-molding technology or plastic potting technology.
4. Inductive component according to claim 1, comprising at least one second magnetic core which is formed as a plastic-bonded magnetic core or a core of magnetic cement and which surrounds said bus bar at least in part, wherein said at least two magnetic cores are arranged along said bus bar in series and a bus bar section is formed between each two magnetic cores for electrically connecting to a capacitor.
5. Inductive component according to the claim 4, further comprises a housing in which said bus bar is accommodated at least in part, wherein said at least two magnetic cores are formed in said housing in separate housing sections.
6. Inductive component according to claim 1, wherein said at least one magnetic core is formed as a plastic-bonded magnetic core made of a plastic ferrite material or of a plastic material with magnetically conductive particles embedded therein.
7. High-current filter with at least one capacitor and said inductive component according to claim 1, wherein said at least one capacitor is electrically connected to said bus bar.
8. Method for producing an inductive component comprising: providing a bus bar; and forming at least one magnetic core formed along a section of said bus bar and surrounding said bus bar in said section at least in part, wherein said at least one magnetic core is formed as a plastic-bonded magnetic core or a core made of magnetic cement.
9. Method according to claim 8, wherein forming said at least one magnetic core comprises insert molding said bus bar with plastic ferrite material or plastic material with magnetically-conductive particles embedded therein, wherein a plastic-bonded magnetic core is formed.
10. Method according to claim 8, wherein said bus bar is arranged at least in part in a housing and forming said at least one magnetic core comprises potting said bus bar in said housing at least in sections with a plastic ferrite material or plastic material with magnetically-conductive particles embedded therein or a cement with magnetically-conductive particles embedded therein.
11. An inductive component comprising: a bent bus bar having a plurality of installation spaces between opposing ends, wherein a portion of said bent bus bar is U-shaped; a contact region placed at each of the opposing ends; a plastic-bonded magnetic core formed around a portion of said formed bus bar at one of the plurality of installation spaces.
12. An inductive component as in claim 11 further comprising: a housing holding said bent bus bar; a plurality of partition walls placed in said housing forming housing sections; and wherein one of the plurality of installation spaces is held within each of the housing sections, whereby said plastic-bonded magnetic core formed around a portion of said formed bus bar at one of the plurality of installation spaces is held within the housing sections.
Description
[0031] A circuit diagram of a high-current filter 1 according to some illustrative embodiments of the present invention shall now be described with reference to
[0032] Three inductances L1, L2 and L3 are connected in series between the input terminal and the output terminal. Interposed between input terminal E and inductance L1 is a capacitance C1, where one electrode of capacitance C1 is connected between input terminal E and inductance L1, while the other electrode of capacitance C1 is connected to ground M. Interposed between inductance L1 and inductance L2 is a capacitance C2, where one electrode of capacitance C2 is connected between inductances L1 and L2, and the other electrode of capacitance C2 is connected to ground M. Interposed between inductance L2 and inductance L3 is a capacitanceC3, where one electrode of capacitance C3 is connected between inductances L2 and L3, and the other electrode of capacitance C3 is connected to ground M. Interposed between inductance L3 and output terminal A is a capacitance C4, where one electrode of capacitance C4 is connected between inductance L4 and output terminal A, while the other electrode of capacitance C4 is connected to ground M.
[0033] According to illustrative examples herein, it can be true that C1=C2=C3=C4. Alternatively, at least one capacitance of capacitances C1 to C4 can be different.
[0034] According to one illustrative example, it can be true that C1≈C2≈C3≈C4, wherein “≈” means a deviation of at most 30%, for example, at most 20%, preferably at most 15%, more preferably at most 10%, approximately at most 5%.
[0035] Circuit T shown schematically in
[0036] The circuit diagram shown in
[0037] The circuit diagram shown in
[0038] Various illustrative embodiments of the invention shall be described in more detail below with reference to
[0039]
[0040] According to illustrative examples herein, plastic-bonded magnetic core 6a is formed from a plastic ferrite or comprises a plastic matrix into which magnetically-conductive particles are embedded. An example of a plastic matrix are thermoplastic materials. According to specific illustrative examples of the invention, polyamides, PPS or duroplastic material, such as epoxy resins, can be used as matrix material for plastic-bonded magnetic cores. The magnetically-conductive particles can be formed from a ferrite powder and/or a powder of magnetic rare earth materials, for example, NdFeB.
[0041] The term “bus bar” in this specification is to be understood as follows: The term “bus bar” designates an electrical conductor which is configured for operation with a current intensity of at least 5 A (depending on the application, bus bars can be configured for applications of more than 10 A, preferably more than 15 A, for example in a range of 20 A to 1000 A) and/or which is formed as a solid body which can deform only irreversibly (this is to be understood in comparison to a normal wire or power cable which can be deformed reversibly, for example, when wound, provided that it is not kinked. In one illustrative embodiment, the cross-section of a bus bar can be based on the maximum allowable current density determined by the cooling connection and adjoining components and, according to some illustrative examples, be more than 1 A/mm.sup.2, preferably more than 3 A/mm.sup.2, for example in a range of 4 A/mm.sup.2 to 20 A/mm.sup.2.
[0042] Bus bar 4a at its ends comprises contact regions 8a and 10a, where plastic-bonded magnetic core 6a is arranged above bus bar 4a and along bus bar 4a between contact regions 8a and 10a.
[0043] According to illustrative embodiments, as shown schematically in
[0044] According to illustrative examples, holding elements 12a and 14a can further act as contact elements which are adapted to provide an electrical connection between bus bar 4a and a printed circuit board (corresponding to carrier 2a or in addition to carrier 2a). Additionally or alternatively, holding elements 12a and 14a can act as contact elements which electrically connect bus bar 4a to discrete electrical components, for example, to capacitors and/or additional inductances. For example, a parallel connection of further components to plastic-bonded magnetic core 6a can be effected by way of holding elements 12a and 14a acting as contact elements.
[0045] Contact regions 8a and 10a are generally configured to provide electrical contact between bus bar 4a and further bus bars (not shown) electrically connected upstream or downstream, respectively, and/or electric or electronic components (not shown) electrically connected upstream and/or downstream. In other words, contact regions 8a and 10a represent exposed end sections of bus bar 4a which are formed as connecting contacts and at least one bus bar section (described later) exposed at least in part between plastic-bonded magnetic core 6a and contact region 8a or 10a, which can further be adapted for the electrical connection to e.g. a capacitor (not shown).
[0046] In specific illustrative examples, as shown in
[0047] Inductive component 1a shown schematically in
[0048] The inductive component 1 a, which is shown schematically in
[0049] Thereafter, selected bus bar 4a is subjected to deformation to define a shape of bus bar 4a that can depend on available installation space and/or inductive properties that inductive component la has to exhibit. For example, the bus bar can be bent, so that inductive component 1a can be fitted in an available installation space and/or special connection geometries can be produced. For example, a shape of the bus bar determined by an installation situation in a terminal can require that deformation of the non-deformed initial bus bar is to occur in accordance with the particular shape and that e.g. sections bent to a U-shape are to be formed, that connection conditions or connection geometries must be fulfilled and/or that the bus bar is to be fitted in a predetermined installation space. Although parasitic capacitances are generally undesirable and generally to be suppressed, it is nevertheless also conceivable to additionally or alternatively deform the bus bar in order to set a desired capacitance value of the bus bar, for example, by deforming the bus bar in sections such that e.g. sections of the bus bent to a U-shape are adapted to set a parasitic capacitance.
[0050] In an illustrative example, as shown in
[0051] Due to these factors, complex bus bar shapes can arise that can be easily populated with plastic-bonded magnetic cores according to the present method, as shall be discussed below.
[0052] Thereafter, plastic-bonded magnetic core 6a is formed on bus bar 4a. For example, plastic-bonded magnetic core 6a can be formed by overmolding bus bar 4a with plastic ferrite material or generally material comprising a plastic matrix with magnetically-conductive particles embedded therein. Alternatively, plastic-bonded magnetic core 6a can be formed by potting bus bar 4a in sections with a potting material, where the potting material comprises a plastic matrix with magnetic particles embedded therein.
[0053] Thereafter, respectively obtained bus bar 4a with plastic-bonded magnetic core 8a can be attached to a carrier 2a (for example, a plastic carrier or a printed circuit board).
[0054] Additionally or alternatively, bus bar 4a with plastic-bonded magnetic core 6a can be accommodated in a housing, provided that bus bar 4a has not already been arranged in a housing for the production of plastic-bonded magnetic core 6a.
[0055] An inductive component 1b shall be described with reference to
[0056] Inductive component 1b illustrated in
[0057] According to illustrative examples herein, each plastic-bonded magnetic core 5b, 6b and 7b is formed from a plastic ferrite or comprises a plastic matrix into which magnetically-conductive particles are embedded. An example of a plastic matrix are thermoplastic materials. According to specific illustrative examples of the invention, polyamides, PPS or duroplastic material, such as epoxy resins, can be used as matrix material for plastic-bonded magnetic cores. The magnetically-conductive particles can be formed from an iron powder, a powder of an iron alloy (e.g., FeSi, NiFe, FeSiAl, etc.), a ferrite powder and/or a powder of magnetic rare earth materials, e.g. NdFeB.
[0058] Bus bar 4a at its ends comprises contact regions 8b and 10b, where plastic-bonded magnetic cores 5b, 6b and 7b are arranged above bus bar 4a and along bus bar 4a between contact regions 8b and 10b.
[0059] According to illustrative embodiments, as shown schematically in
[0060] Holding elements 12b and 14b are provided in an illustrative manner at sections of bus bar 4a which are respectively not covered by plastic-bonded magnetic core 5b, 6b and 7b, and therefore represent exposed bus bar sections. Holding element 12b is disposed between plastic-bonded magnetic cores 5b and 8b, whereas the holding element is disposed between plastic-bonded magnetic cores 6b and 7b. Further holding elements (not shown) can be provided. For example, another holding element (not shown) can be disposed between plastic-bonded magnetic core 5b and contact region 8b, and another holding element (not shown) can be disposed between plastic-bonded magnetic core 7b and contact region 10b.
[0061] According to illustrative examples, holding elements 12b and 14b (as well as the (optional) further holding elements not shown in
[0062] In a specific example, bus bar 4b can be almost completely surrounded by a material for plastic-bonded magnetic cores 5b, 6b, 7b, and only contact regions 8b, 10b and sections can be exposed on the bus bar that are in mechanical (and optionally electrical) contact with holding elements 12b and 14b. If, in this example, holding elements 12b and 14b further act as electrical contact elements by way of which bus bar 4b can be connected in parallel to e.g. discrete electrical components (e.g., a capacitor), then only the surface sections of bus bar 4b to be mechanically and electrically connected to holding elements 12b, 14b may not be covered with plastic-bonded magnetic cores 5b, 6b, 7b between contact regions 8b, 10b. Although in this case plastic-bonded magnetic cores 5b, 8b, 7b represent a contiguous amount of material, effective inductances along the bus bar between contact regions 8b, 10b are provided by holding elements 12b and 14b acting as contact elements, so that three plastic-bonded magnetic cores can effectively be spoken of in this case as well.
[0063] Contact regions 8b and 10b are generally configured to provide electrical contact between bus bar 4b and further bus bars (not shown) electrically connected upstream or downstream, respectively, and/or electric and/or electronic components (not shown) electrically connected upstream and/or downstream. In other words, contact regions 8b and 10b represent exposed end sections of bus bar 4b which are formed as connecting contacts and comprise at least one bus bar section (shall be described later), exposed at least in part between plastic-bonded magnetic cores 5b or 7b and a contact region 8b or 10b, which can further be adapted for the electrical connection to e.g. a capacitor (not shown).
[0064] In specific illustrative examples, as shown in
[0065] Inductive component 1b shown schematically in
[0066] The inductive component 1 b, which is shown schematically in
[0067] Thereafter, selected bus bar 4b is subjected to deformation to define a shape of bus bar 4b that can depend on available installation space and/or that can exhibit specific connection geometries. For example, a shape of the bus bar determined by an installation situation in a terminal can require that the deformation of the non-deformed initial bus bar is to occur in accordance with the particular shape and that e.g. sections bent to a U-shape are to be formed, that connection conditions or connection geometries must be fulfilled and/or that the bus bar is to be fitted in a predetermined installation space It is also conceivable that a deformation of the selected bus bar can depend on inductive properties that inductive component 1b has to exhibit. For example, the bus bar can be bent such that inductive component 1b can be fitted in an available installation space. For example, several U-shaped sections, for example in serpentine form, can be formed between contact regions 8b and 10b in bus bar 4b (not shown in
[0068] Thereafter, plastic-bonded magnetic cores 5b, 6b and 7b are formed on bus bar 4b. For example, plastic-bonded magnetic cores 5b, 6b and 7b can be formed by insert molding bus bar 4b with plastic ferrite material or generally material comprising a plastic matrix with magnetically-conductive particles embedded therein. Alternatively, plastic-bonded magnetic cores 5b, 6b and 7b can be formed by potting bus bar 4b in sections with a potting material, where the potting material comprises a plastic matrix with magnetically-conductive particles embedded therein. This is no restriction of the present invention, but some plastic-bonded magnetic cores can also be formed by insert molding, while other plastic-bonded magnetic cores are formed by potting.
[0069] Thereafter, respectively obtained bus bar 4b with the plastic-bonded magnetic cores 5b, 6b and 7b can be attached to a carrier 2b (for example, a plastic carrier or a printed circuit board).
[0070] Additionally or alternatively, bus bar 4b with plastic-bonded magnetic cores 5b, 6b and 7b can be accommodated in a housing, provided that bus bar 4b has not already been arranged in a housing for the production of plastic-bonded magnetic cores 5b, 6b and 7b.
[0071] Further illustrative embodiments of the present invention shall now be described with reference to
[0072]
[0073] This is no restriction of the present invention, and bus bar 104 can alternatively be completely accommodated in housing 101 (not shown)
[0074] Housing 101 comprises housing sections A1, A2, A3, A4 and A5 which are separate from one another. The number of separate housing sections is arbitrary and can be suitably selected according to an intended application. In the example of the embodiment illustrated in
[0075] Provided in partition walls TW1 to TW4 are recesses (not shown) for receiving bus bar 104 which extends through these recesses (not shown), so that bus bar 104 passes through the various housing sections Al to A5. The recesses (not shown) in partition walls TW1 to TW4 can be formed in partition walls TW1 to TW4 according to a shape of bus bar 104 (obtained after a deforming process, as previously described with respect to
[0076] By potting individual housing sections, housing sections A2 and A4 in the example in the illustration in
[0077] According to some illustrative embodiments, bus bar 104 in housing section A1 is electrically connected between contact end 108 and plastic-bonded magnetic core 106a by way of a contact point 112a to a capacitance 113a that can be accommodated in housing section A1. Capacitance 113a, e.g. a capacitor, accommodated in housing section A1 can further be connected by way of a contact point Ma to a ground line outside housing 101. This is no restriction of the present invention, and capacitance 113a can instead also be provided outside housing 101.
[0078] According to some illustrative embodiments, bus bar 104 in housing section A3 is electrically connected between contact end 106a and plastic-bonded magnetic core 106b by way of a contact point 112b to a capacitance 113b, e.g. a capacitor that can be accommodated in housing section A3. Capacitance 113b accommodated in housing section A3 can further be connected by way of a contact point Mb to a ground line outside housing 101. This is no restriction of the present invention, and capacitance 113b can instead also be provided outside housing 101.
[0079] According to some illustrative embodiments, bus bar 104 in housing section A5 is electrically connected between contact end 110 and plastic-bonded magnetic core 106b by way of a contact point 112c to a capacitance 113a that can be accommodated in housing section A5. Capacitance 113c, e.g. a capacitor, accommodated in housing section A5 can further be connected by way of a contact point Mc to a ground line outside housing 101. This is no restriction of the present invention, and capacitance 113c can instead also be provided outside housing 101.
[0080] According to illustrative embodiments, capacitances 113a, 113b, and 113c can be provided as discrete electrical components respectively accommodated in housing sections A1, A3, and A5. Alternatively, capacitances 113a, 113b and 113c can be provided in a printed circuit board (not shown) or connected to a printed circuit board (not shown), where the printed circuit board (not shown) can represent a base C of housing 101 (not shown) or be arranged on the base (not shown) of housing 101, respectively.
[0081] An illustrative method for producing an inductive component according to the present invention shall now be described with reference to
[0082] Thereafter, in a step S2, at least one plastic-bonded magnetic core can be formed which is formed according to illustrative embodiments along a section of the bus bar and surrounds the bus bar at least in part in that section.
[0083] According to specific illustrative examples herein, the at least one plastic-bonded magnetic core can be formed in step S2 by insert molding the bus bar with a plastic ferrite material, or generally by insert molding the bus bar with a plastic material having magnetically-conductive particles embedded therein.
[0084] According to alternative examples herein, the bus bar can be arranged at least in part in a housing between step S1 and step S2. In step S2, the at least one plastic-bonded magnetic core can then be formed by potting the bus bar in the housing at least in sections with a plastic ferrite material or generally a plastic material with magnetically-conductive particles embedded therein. An example of a plastic matrix is thermoplastic materials. According to specific illustrative examples of the invention, polyamides, PPS or duroplastic material, such as epoxy resins, can be used as matrix material for plastic-bonded magnetic cores. The magnetically-conductive particles can be formed from an iron powder, a powder of an iron alloy (e.g., FeSi, NiFe, FeSiAl, etc.), a ferrite powder and/or a powder of magnetic rare earth materials, e.g. NdFeB.
[0085] Alternatively, a magnetic core can be formed from magnetic cement in that housing sections are potted with the magnetic cement and the magnetic cement cures.
[0086] The bus bar with the at least one plastic-bonded magnetic core is subsequently attached and/or electrically connected to a carrier material, such as a plastic carrier or a printed circuit board.
[0087] In specific illustrative embodiments of the present invention, as explained above with reference to
[0088] The inductive component can be provided, for example, in a filter module to filter differential mode noise. According to a suitable deformation of the provided bus bar, also complex bus bar geometries can there be used, since the plastic-bonded magnetic cores provide no restriction of the bus bar shape as compared to known solutions with magnetic cores, which are provided for example by folding ferrites that are folded around or snapped around bus bars, a plastic-bonded magnetic core, as described above with respect to the illustrative embodiments, can better utilize a given space than discrete cores. Filter modules can therefore be manufactured also for compact installation spaces. Manufacturing processes can there be automated or can comprise automated injection-molding processes or potting processes. In processes, in which plastic-bonded magnetic cores are produced by potting, additional fixation of the bus bar by additional components is dispensed with.
[0089] the industrial production is improved in this regard due to the foregoing advantages and the great freedom in the design of the bus bar, since there are no restrictions on the design of the bus bar by the requirements in terms of the installability of inductive components.
[0090] In specific illustrative embodiments of the present invention, almost entire insert molding of a bus bar can take place for high-current filters with very large cross-sections, where only regions can be excluded to which further components, for example, capacitances, are connected. Alternatively, the almost entire potting of the bus bar can take place instead of the almost entire plastic ferrite insert molding, where an additional mechanical protection of the assembly can be provided by the potting.
[0091] inductances of the plastic-bonded magnetic cores are easily adjustable in a large inductance range by way of the plastic-bonded magnetic cores, for example in a range from 10 nH to 200 nH, preferably in the range from 40 nH to 90 nH or in a range from 150 nH to 300 nH.
[0092] Plastic-bonded magnetic cores have been describe above with reference to