Holder for a choke coil and an inductive component with the holder

[0001] This application is a continuation of co-pending International Application No. PCT/DE2005/001168, filed Jul. 1, 2005, which designated the United States and was not published in English, and which is based on German Application No. 10 2004 037 853.3, filed Aug. 4, 2004, both of which applications are incorporated herein by reference.

[0002] The invention relates, in one aspect, to a holder for a choke coil and in a further aspect to an inductor with the holder and a choke coil.

[0003] From the publication DE 3330881 A1, a holder for a ring-core choke is known. The holder represents an insulating plate with an attached device for electrical isolation between two choke windings. The ring choke coil is placed on the electrical-isolation device such that different windings are spatially separated from each other. The electrical-isolation device has bars. The outer end edges of the bars touch the ring core of the choke in a spring-like manner.

[0004] The objective of the invention is to specify a material-saving and space-saving holder, which provides for electrical isolation of the windings from one another at a ring core choke with several windings and which can be produced simply.

[0005] The invention specifies an electrically isolating holder for carrying a ring-core choke with a closed magnetic core (preferably a ring core or a ring core featuring a gap) and at least two wire windings. The holder has a center part and hinged side lugs connected to this part. The holder further has means for fixing the side lugs in the folded together state, the lugs being preferably arranged essentially parallel to one another in the folded together state. The side lugs each feature an isolating element, which is used for separating or electrically isolating the windings of the choke attached to different ring core sections.

[0006] The side lugs preferably are located opposite to one another and can be folded on both sides against the ring core.

[0007] Further embodiments of the invention relate to an inductive component with the holder and a ring-core choke, which has a ring core and at least two wire windings to be isolated from each other.

[0008] Embodiments of the invention have the advantage that the holder functions, in addition to the function as a sub-housing, simultaneously as electrical isolation between different wire windings. The holder accordingly can be produced in a material-saving way and simply, e.g., in an injection molding method.

[0009] In a preferred variant of the invention, all of the elements of the holder, i.e., the center part, the side lugs, the isolating bars are formed as one piece with optional attachment devices constructed therein. In another variant, the side lugs can be attached to the center part, e.g., by hooks.

[0010] The side lugs are preferably held parallel to each other by a part of the holder, e.g., by means of isolating elements.

[0011] Each isolating element preferably has at least two isolating bars. The length of the isolating bars of opposing side lugs is preferably selected so that they touch each other when the side lugs are folded together. The isolating bars are arranged on the inner side of the side lugs. The isolating lugs are pushed into the ring core opening, wherein the longitudinal axis of the isolating bars is preferably oriented parallel to the center axis of the ring-core choke. Preferably, the side edge or one area of the outer surface of the isolating bar touches the inner surface of the ring core in a spring-like way.

[0012] The opposing isolating bars can have corresponding attachment devices, e.g., clamping devices or latch devices, which are preferably formed in the isolating bars.

[0013] In the center part of the holder, preferably there are openings for the passage of the winding wires to form connection terminals. These openings are used to establish the lead wire spacing of the corresponding inductive component.

[0014] In the center part of the holder, openings for holding attachment elements, e.g., screws or attachment bolts, are also provided. By means of the attachment elements, the component can be fixed onto a circuit board. In the center part of the holder, preferably there is a recess for holding the ring-core choke.

[0015] In one variant of the invention, together with vertical walls, the side lugs can form half-shells, whose openings point towards each other in the folded-together state. Here, a housing is formed that surrounds the coil arranged therein, preferably on all sides, and therefore is suitable, in particular, for protection against electrical shock. The side lugs and the vertical walls preferably have an integral construction.

[0035] The following list of reference symbols can be used in conjunction with the figures:

[0036]

1	Holder
10	Center part of holder
11	First side lug of holder
12	Second side lug of holder
100, 101	Recess for holding the ring-core choke (recess or bulge)
110	End wall of first side lug 11
111	Upward-turned wall of first side lug 11
120	End wall of second side lug 12
121	Upward-turned wall of second side lug 12
21, 22	Isolating bars
23, 24	Isolating bars
21a	Attachment device on isolating bar 21
23a	Attachment device on isolating bar 23
31, 31′	Openings for holding connections 52, 52′ of wire winding 53a
32, 32′	Openings for holding connections 51, 51′ of wire winding 53b
4	Spacer
5	Ring-core choke
51	Connection of second wire winding 53b
52, 52′	Connections of first wire winding 53a
53a	First wire winding of ring-core choke 5
53b	Second wire winding of ring-core choke 5
54	Magnetic ring core

[0037] FIGS. 1A to 3B show different views of the first preferred embodiment of the holder 1 with a center part 10 and two opposing side lugs 11 and 12 connected to the center part 10.

[0038] In FIGS. 1A, 1B, 6B, and 6A, the state of the holder before folding the side lugs 11 and 12 over is indicated by the solid lines. In these figures, the dashed lines show the state of the holder 1 after the side lugs 11 and 12 are folded together.

[0039] FIG. 1A shows a schematic top view of the holder 1. In FIG. 1B, the holder 1 is shown with the side lugs 11 and 12 folded together.

[0040] After being folded over, the side lugs 11 and 12 are essentially parallel to each other and perpendicular to the surface of the center part 10. A recess 100 for holding the ring-core choke 5 (see FIG. 4) is formed in the center part 10. The recess 100 preferably has a round cross section—see FIGS. 3A and 5B—and is adapted to the shape of the ring-core choke arranged therein.

[0041] In the center part 10, there are openings 32 and 32′ for holding connections 52 and 52′ of the first wire winding 53a of the ring-core choke 5 (also see FIGS. 4A and 5B). In addition, in the center part 10 there are openings 31 and 31′ for holding connections 51 of a second wire winding 53b of the ring-core choke 5. The lead wire spacing of the corresponding inductive component with the ring-core choke 5 is guaranteed by the openings 31, 31′, 32 and 32′.

[0042] In addition, as shown in FIG. 1C, spacers 4 are formed in the center part 10. These are used as distancing elements for maintaining a distance between the holder of the component and an underlying system carrier, e.g., circuit board, so that the gases generated during the soldering of the component to the printed conductors of the system carrier can escape. The spacers 4 can be formed as projections of the center part 10 of the holder. The spacers 4 can also be formed as separate elements and be rigidly connected to the center part 10.

[0043] The side lug 11 has isolating bars 21 and 22, as shown in FIG. 1B. The second side lug 12 also has isolating bars 23 and 24. The appropriate side lug 11 (or 12) and the isolating devices 21 and 22 (or 23 and 24) allocated to it are integrally formed together. The isolating bar 21 of the first side lug 11 corresponds to the isolating bar 23 of the second side lug 12. The isolating bar 22 corresponds to the isolating bar 24.

[0044] When the side lugs 11 and 12 are folded together, the isolating bars 21 and 23 (and also 22 and 24) are turned towards each other, preferably touching one another.

[0045] The adjacent wire windings 53a and 53b are held at a distance from each other by the isolating bars 21, 22, 23 and 24 and therefore are electrically isolated from each other; see FIG. 5C. Thus, the electrical isolation between the different wire windings 53a and 53b of the ring-core choke 5 is realized by the isolating bars 21 to 24.

[0046] FIG. 1C shows the holder 1 in a schematic view from below. In FIG. 2A, the front view of the holder according to FIGS. 1A to 1C is shown perpendicular to the side lug 11. FIG. 2B shows a side view of the holder 1 for the side lugs 11 and 12 folded together in the direction parallel to the side lugs. FIG. 3B shows the corresponding cross-sectional view of the holder 1 for the cross section perpendicular to the side lugs.

[0047] FIG. 3A shows the cross section of the holder 1 through the center part 10 parallel to the side lugs 11 and 12 with the view of the folded side lug 12 from the inside.

[0048] In FIGS. 4A to 4D, processing steps for the assembly of a ring-core choke 5 in the holder 1 are shown schematically.

[0049] The ring-core choke 5 has a magnetic ring core 54 and also two different wire windings 53a and 53b (FIG. 4A, where only 53a is visible). In FIG. 5B, note that different wire windings 53a and 53b of the ring-core choke are placed on different sections of the ring core. The first wire winding 53a has the electrical connections 52 and 52′. The second wire winding 53b has the electrical connections 51 and 51′.

[0050] The connections 51, 51′, 52 and 52′ or the wire windings 53a and 53b are inserted through the openings 31, 32 and 32′ of the center part 10 (FIG. 4B). The ring-core choke 5 is set with its outer surface on the center part 10 of the holder 1.

[0051] Then the first side lug 11 is folded against the end of the magnet core (FIG. 4C). Here, the isolating bars 21 and 22 are inserted into the inner hole of the magnet core, so that they touch the inner surface of the magnet core in a spring-like way.

[0052] In FIG. 4D, it is shown that the second side lug 12 is folded against the ring-core choke. Here, the isolating bars 23 and 24 are inserted into the inner hole of the magnet core 54. They touch the inner surface of the magnet core in a spring-like way.

[0053] FIG. 4D shows the inductive component, i.e., the holder 1 with the ring-core choke 5 mounted thereon, in a schematic side view in the direction parallel to the side lugs 11 and 12. The front view of this component is shown in FIG. 5A.

[0054] A view of the inductive component from the inside is shown in FIG. 5B. The cross section of the recess 100 is adapted to the cross section of the magnet core 54. An adhesive, with which the magnet core 54 is fixed in the recess 100 of the holder 1, is preferably placed in the recess 100 before the ring-core choke 5 is inserted.

[0055] In FIG. 5C, the aforementioned inductive component is shown in a schematic cross section perpendicular to the side lugs 11 and 12.

[0056] The side lugs 11 and 12 are preferably held in the folded state parallel to each other by means of the isolating bars. The side lugs 11 and 12 can be held parallel to each other, e.g., by a press fit of the isolating bars 21 to 24 in the magnet core 54. Here, the isolating bars 21 to 24 are pushed into the inner hole of the magnet core 54, so that the isolating bars press against the inner surface of the magnet core. Another example possibility for fixing the side lugs when folded is shown in FIG. 7.

[0057] The ring-core choke 5 can be mounted on the holder 1 by means of an adhesive in the recess 100.

[0058] The isolating elements of the holder 1 are inserted into the center opening of the ring-core choke 5 and preferably touch the inner surface of the ring core 54 in a spring-like way.

[0059] The holder 1 according to FIGS. 1A to 3B forms a sub-housing of the inductive component. In FIGS. 6A to 6D, a second preferred embodiment of the holder according to the invention is shown. In this case, the holder 1 forms a complete housing of the inductive component.

[0060] FIG. 6A shows a schematic top view of the holder 1. FIGS. 6B and 6D show a schematic side view of the holder according to FIG. 6A. FIG. 6C shows a schematic bottom view of the holder 1. The FIG. 6D shows the side view of the holder 1 for the folded-together side lugs 11 and 12 in the direction parallel to the side lugs. In FIG. 6E, the front view of the holder according to FIGS. 6A to 6D is shown perpendicular to the side lug 11. FIG. 6F shows the cross-sectional view of the holder 1 for the cross section perpendicular to the side lugs.

[0061] In FIG. 6A it is to be seen that the side lug 11 is provided on three sides with the walls 110, 111, and 110′. The walls 110, 110′ and 111 here stand perpendicular to the surface of the side lug 11. The side lug 11 forms a first half-shell together with the walls 110, 110′, and 111. The walls 110 and 110′ are the opposing end walls of the first half-shell. Wall 111 is the wall of the first half-shell facing upwards. The second side lug 12 is likewise provided with three walls 120, 120′, and 121. The walls 120, 120′ and 121 stand perpendicular to the surface of the side lug 12. The side lug 12, together with these side walls, forms a second half-shell, whose shape is preferably mirror-symmetric to the first half-shell. When the side lugs 11 and 12 are folded together, the walls 110 and 120, 110′ and 120′, 111 and 121 are turned towards each other.

[0062] The center part 10, the side lugs 11 and 12, the isolating bars 21 to 24, and the walls 110, 110′, 111, 120, 120′ and 121, are preferably formed together as one integral element.

[0063] In FIGS. 6D and 6F it is to be seen that when the side lugs 11 and 12 are folded over, the walls 111 and 121 (as well as 110 and 120) allocated to opposing side lugs touch each other.

[0064] In an embodiment of the invention proposed in FIG. 7, the opposing isolating bars 21 and 23 are provided with additional attachment devices 21a and 23a (here latch elements), wherein the isolating bars 21 and 23 of the different side lugs can be hooked to each other.

[0065] The invention is not limited to the embodiments shown here or to a particular selection of materials. The proposed elements can be combined with each other in any number and arrangements. The attachment devices for fixing the side lugs can also be clamping devices. The invention is also not limited to ring cores with a round cross section.