Choke arrangement and receptacle for the choke arrangement

Abstract

The invention, which relates to a choke arrangement (1) for application in an EMC filter, has as its objective specifying a choke arrangement (1) that is mechanically robust and that enables improved insulation of the windings (4, 5). The objective is attained by disposing about the toroidal core (10) a two-part enclosure (15) and by disposing an insulation web (19) in the two-part enclosure (15).

Claims

1. A choke arrangement for application in an electromagnetic compatibility filter, comprising a toroidal core and at least two windings which are disposed on the toroidal core under electrical isolation, wherein a two-part enclosure is disposed about the toroidal core, wherein the two-part enclosure is formed of two structurally identically formed half shells which are disposed such that they are oriented with their coupling joints toward one another, wherein an insulation web is disposed in the two-part enclosure such that the insulation web extends through the inner diameter of each of the half shells as well as also in a region across the outer diameter of each of the half shells, wherein the coupling joints of the half shells are stepped, and wherein a stepping is formed in the region of the insulation web, so that the half shells are accurately fixed and are prevented from twisting by the stepping.

2. A choke arrangement according to claim 1, wherein a mounting plate is disposed securing in position the wire ends of the windings of the choke arrangement.

3. A choke arrangement according to claim 1, wherein connector pins are disposed on the mounting plate.

4. A choke arrangement according to claim 1, wherein the windings are disposed on the two-part enclosure.

5. A receptacle for a choke arrangement according to claim 1, wherein the choke arrangement is disposed in a receptacle encompassing the choke arrangement and securing the same in position.

6. A receptacle according to claim 5, wherein the receptacle comprises a U-shaped retainer in which is disposed the portion of the insulation web projecting beyond the outer diameter of each of the half shells.

7. A receptacle according to claim 6, wherein the U-shaped retainer is disposed extending over the three internal sides of the receptacle.

8. A receptacle according to claim 6, wherein the choke arrangement is a choke arrangement disposable into the U-shaped retainer of the receptacle by being slid into it using the insulation web.

Description

(1) Further details, characteristics and advantages of embodiments of the invention are evident based on the following description of embodiment examples with reference to the associated drawing. Therein depict:

(2) FIG. 1: an exemplary circuit configuration of a passive EMC filter according to prior art by example of an EMC filter circuit with a choke arrangement, in particular a common mode choke,

(3) FIG. 2: a prior art common mode choke comprising a toroidal core with two windings applied in opposite winding directions,

(4) FIG. 3: a two-part enclosure according to the invention receiving or encompassing a toroidal core,

(5) FIG. 4: a half shell of the two-part enclosure according to the invention,

(6) FIG. 5: two half shells implemented of equal structure after assembly to form the enclosure with a stepped coupling joint,

(7) FIG. 6: schematic diagram of the placement of a choke arrangement with a control board of an inverter for activating an electric refrigerant compressor,

(8) FIG. 7: a receptacle suitable for the placement of the choke arrangement according to the invention, and

(9) FIG. 8: a depiction of the introduction of the choke arrangement according to the invention into a frame.

(10) FIG. 1 shows an exemplary circuit configuration of a passive EMC filter with a choke 1′ according to prior art, wherein the EMC filter is connected to an inverter 2. The EMC filter circuit, implemented as a passive filter, comprises an input 3 to which a voltage, for example of 48 V, can be applied and comprises the first winding L.sub.1 4 and the second winding L.sub.2 5 in feed lines HV+ and HV−, which windings are disposed on a common core, such as for example a toroidal core 10.

(11) While a first capacitor 6 with the designation C.sub.1 is located between lines HV+ and HV− directly at the input of the passive EMC filter circuit and ahead of windings L.sub.1 4 and L.sub.2 5, a second capacitor 7 with the designation C.sub.2 is located behind windings L.sub.1 4 and L.sub.2 5 at the output of the EMC filter circuit and consequently at the input of the inverter 2.

(12) A third capacitor 8 with the designation C.sub.3 is provided between line HV− and ground potential. A fourth capacitor 9 with the designation C.sub.4 is located between line HV+ and ground potential.

(13) As is conventional in prior art, the inverter 2 generates the electrical control signals required for operating an electric motor, not shown, which drives, for example, a refrigerant compressor.

(14) In FIG. 2 is shown a choke 1′ in particular a common mode choke of prior art, which is realized of a toroidal ring core 10 with two windings 4 and 5 applied in opposite winding directions. To receive the wire ends of the first winding 4 as well as of the second winding 5, a mounting plate 11 is provided. The wire ends are, for example, soldered or welded to corresponding contact points or conductor tracks on the mounting plate 11 to be electrically conducting.

(15) In addition, it is customary to secure the toroidal core 10 in position on the mounting plate 11 by means of an adhesive 12. The unit, comprised of the toroidal core 10, the first winding 4, the second winding 5 and the mounting plate 11, can be connected by means of connector pins 13 on the mounting plate 11 with a control board, not shown in FIG. 2, of an inverter. To establish an electrically conductive connection of the connector pins 13 with contact points or conductor tracks of the control board of an inverter, soldering methods or welding methods can be employed for example.

(16) To electrically insulate the first winding 4 from the second winding 5, an insulation plate 14 is disposed in the inner diameter of the toroidal core 10. The insulation plate 14 is, for example, mechanically secured in place by means, for example, of an adhesive 12 in the inner diameter of the toroidal core 10.

(17) FIG. 3 shows a choke arrangement 1 according to the invention with a two-part enclosure 15 receiving or encompassing a toroidal core 10. The two-part enclosure 15 is formed by means of a first half shell 16 and a second half shell 17. Both half shells 16, 17 include a coupling joint 18 which is formed such that the joining of the first half shell 16 and of the second half shell 17 is possible without a residual interspace remaining between the half shells 16, 17.

(18) After the toroidal core 10 has been placed into the two-part enclosure 15, the half shells 16, 17 can be adhered together, for example by means of an adhesive 12. The first winding 4 and the second winding 5 are subsequently applied utilizing a winding method known in prior art and the choke arrangement 1 is completed. To improve the view of the half shells 16, 17, windings 4 and 5 are not depicted in FIG. 3.

(19) The half shells 16, 17 are each developed comprising a portion of an insulating web 19. After the half shells have been assembled, the insulation web 19 is complete and extends through the inner diameter of the half shells 16, 17 as well as also in a region across the outer diameter of the half shells 16, 17.

(20) The insulation web 19 which, compared to prior art, is larger, leads, on the one hand, to an improvement of the insulation between the first winding 4 and the second winding 5 and, on the other hand, to an improvement of the mechanical strength and stability of the two-part enclosure and consequently of the choke arrangement 1. The formulation of a larger insulation web 19 means that the insulation web 19 is also implemented beyond the outer diameter of the two-part enclosure 15 as well as also that the web is realized around the cross section of the two-part enclosure 15 and thus also around that of the toroidal core 10. The improvement of the mechanical strength and stability affects the two-part enclosure 15 as well as also the improved protection of the brittle material of the toroidal core 10, especially during the process of winding onto the toroidal core 10, for example in two windings 4, 5.

(21) The half shells 16, 17 are advantageously realized and produced in identical form such that the half shells 16, 17 can be produced, for example, in a single injection mold. In addition, in this way high accuracy of fit of the half shells 16, 17 with one another is given.

(22) The choke arrangement 1 according to the invention comprises additionally a first winding 4 and a second winding 5 that are not depicted in FIG. 3. The first winding 4, for example in the region shown in FIG. 3, can be disposed to the left of the insulation web 19 according to the invention and the second winding 5 can be disposed to the right of the insulation web 19 according to the invention. Limitation of the invention to this form of disposition of several windings 4, 5 or a limitation to only two windings 4, 5 is not intended.

(23) FIG. 4 shows the first half shell 16 of the two-part enclosure 15 according to the invention in a view onto the inner side of the first half shell 16. Alternatively, the depiction could also show the second half shell 17 since the two half shells 16, 17 are implemented in identical form.

(24) The half shells 16, 17 are realized such that a toroidal core 10 is emplaceable into the half shells 16, 17. The interior region of the half shells 16, 17 is adapted to the cross sectional form of the toroidal core 10. In the example of FIG. 4 the toroidal ring core 10 has a rather rectangular, in particular square, cross section. In an alternative embodiment the toroidal ring core 10 could have a rather circular cross section. In this case it is intended to implement at least the interior region of the half shells 16, 17 semicircularly.

(25) The interior is adapted in every case to the contours of the toroidal core 10 such that an inclusion of the toroidal core 10 in the two-part enclosure 15 under form closure is attained. Therewith the toroidal core 10 is well secured in position in the two-part enclosure 15 and protected against mechanical effects. The protection involves mechanical stresses which occur during the winding in the production of the choke arrangement 1 as well as also mechanical stresses such as vibrations which occur, for example, in a completed assembly of an inverter for a refrigerant compressor that includes the choke arrangement 1.

(26) The half shells 16, 17 have each a coupling joint 18. A coupling joint 18 represents the region or the surface with which the half shells 16, 17 are in contact after they have been assembled. In a first variant is provided to implement the coupling joints 18 planarly such that the first coupling joint 18 of the first half shell 16 is in contact flat on the second coupling joint 18 of the second half shell 17. The half shells 16, 17 can be adhered with one another for example in the region of the coupling joint 18.

(27) According to an alternative embodiment, the coupling joints 18 of half shells 16, 17 are implemented with a stepping 20 or are stepped. In FIG. 4 by example two steppings 20 are encircled. The steppings 20 are developed in such manner that the half shells 16, 17 mutually complement each other without any gap or hollow space in the connection regions of the coupling joints 18 exhibited by the two-part enclosure 15. The half shells 16, 17 are moreover by means of such stepping 20 fixed precisely in position and secured against twisting.

(28) FIG. 5 shows two structurally identically implemented half shells 16, 17 that are joined to form a two-part enclosure 15. The toroidal core 10 disposed in the two-part enclosure 15 is not visible in FIG. 5. The half shells 16, 17 are provided with a stepped coupling joint 18, wherein a stepping 20 is depicted which is formed in the region of the insulation web 19 according to the invention. The arrow illustrates the emplacement of the first half shell 16 onto the second half shell 17 to provide the two-part enclosure 15. For the completion of the choke arrangement 1 according to the invention, on the two sides of the insulation web 19 one winding 4 or 5 is disposed, which is not shown in FIG. 5.

(29) FIG. 6 shows a schematic diagram of the positioning of a choke arrangement 1 with a control board 21 of an inverter for actuating an electric refrigerant compressor.

(30) The first half shell 16 of a two-part enclosure 15 enveloping a toroidal core 10 is shown facing the viewer. On the two-part enclosure 15 the first winding 4 and the second winding 5 is applied. The ends of windings 4 and 5 are connected to a mounting plate 11 wherein the mounting plate 11 comprises connector pins 13. The connector pins 13 are coupled electrically conductively with contact areas or conductor tracks on the control board 21 of an inverter. The two-part enclosure 15 is connected with the mounting plate 11 by means of an adhesive agent 12. The choke arrangement 1 is, in addition, disposed in a receptacle 22 enveloping the choke arrangement 1. The receptacle 22 comprises at least one U-shaped retainer 23 for receiving and securing the insulation web 19 in position. For additional securement, the insulation web 19 is adhered to the U-shaped retainer 23 by means of an adhesive agent 12. The robust disposition of the choke arrangement 1 on the control board 21 of an inverter is ensured.

(31) In FIG. 7 is depicted a receptacle 22 suitable for positioning the two-part enclosure 15. The receptacle 22 comprises a U-shaped retainer 23 on each of three internal sides. The two-part enclosure 15 can be slid into the U-shaped retainer 23 by means of the insulation web 19 extending over the outer diameter. This enables the securement in position of the two-part enclosure 15 in the receptacle 22. Adhering the insulation web 19 in the U-shaped retainer 23 can also be provided.

(32) In this manner the U-shaped retainer 23 enables the strong and stable securement of the two-part enclosure 15 in position. The insulation of the two windings 4, 5 with respect to each other is, moreover, further improved since no air gap can any longer develop between the windings 4, 5. The receptacle 22 can be connected with control board 21 of an inverter, not shown in FIG. 7, by threaded or adhered connection.

(33) In FIG. 8 the process of emplacing the choke arrangement 1 according to the invention is shown, wherein the choke arrangement 1 is shown simplified without windings 4, 5. In the following the receptacle 22 is disposed, for example, on the underside of a control board 21 of an inverter. The arrow illustrates the sliding-in of the two-part enclosure 15 into the receptacle 22. By sliding the choke arrangement 1 with the insulation web 19 into the U-shaped retainer 23 of the receptacle 22 a highly exact positioning of the choke arrangement 1 is attained without additionally necessary means or without additional assembly work. In addition, through the cooperation of the insulation web 19 with the U-shaped retainer 23 the insulation between the first winding 4 and the second winding 5 is greatly improved. The technique of sliding the choke arrangement 1 into the U-shaped retainer 23 not only reduces the required assembly time for securing the choke arrangement 1 in position but also enables the automatic assembly or fabrication of the components or subcomponents which are in connection with the choke arrangement 1.

(34) One advantage of the present invention entails that the insulation of the windings 4, 5 with respect to one another has been improved on the choke arrangement 1 according to the invention in comparison to prior art. Furthermore, a more robust envelopment for the toroidal core 10 was provided, in particular for the application of the winding of the toroidal core 10 with the wire turns of the windings 4, 5.

(35) A further advantage resides in the simplification of the expenditures and effort for the production of the half shells 16, 17 of the two-part enclosure 15 through their structurally identical implementation. Both half shells 16, 17 can therefore be produced, for example, by means of a single injection mold.

(36) Due to the special formation of the two-part enclosure 15 and the integration of the insulation web 19 into the half shells 16, 17, the strength and stability and the resistance to vibrations of the choke arrangement 1 are improved.

(37) Furthermore, through a reception of the choke arrangement 1 with the two-part enclosure 15 in a special frame an improved encapsulation and a further improvement of the insulation properties can be achieved.

LIST OF REFERENCE NUMBERS

(38) 1 Choke arrangement

(39) 1′ Prior art choke

(40) 2 Inverter

(41) 3 Input (HV+/HV−)

(42) 4 First winding L.sub.1

(43) 5 Second winding L.sub.2

(44) 6 First capacitor C.sub.1

(45) 7 Second capacitor C.sub.2

(46) 8 Third capacitor C.sub.3

(47) 9 Fourth capacitor C.sub.4

(48) 10 Toroidal core

(49) 11 Mounting plate

(50) 12 Adhesive agent

(51) 13 Connector pin

(52) 14 Insulation plate (prior art)

(53) 15 Two-part enclosure

(54) 16 First half shell

(55) 17 Second half shell

(56) 18 Coupling joint

(57) 19 Insulation web

(58) 20 Stepping

(59) 21 Control board of inverter

(60) 22 Receptacle

(61) 23 U-shaped retainer