Filter component with windingless magnetic toroidal core, filter assembly and system, and method for producing the same

Abstract

Filter component comprising: a windingless magnetic toroidal core (2) with an opening; a toroidal core housing (3) in which the toroidal core (2) is fastened with a snap mechanism; wherein the filter component (1) is designed such that a conductor (104) can be guided without winding through the opening of the toroidal core (2) fastened in the toroidal core housing (3), wherein the toroidal core housing (3) has a first fastening surface (6) for fastening the toroidal core housing (3), which is arranged parallel to a longitudinal axis (8) of the opening of the toroidal core (2), the toroidal core housing (3) has a toroidal core side (4) for inserting the toroidal core (2) and a toroidal core rear side (5) opposite the toroidal core side (4), wherein the toroidal core side (4) has two feet (14) projecting in the direction of the longitudinal axis (8) of the opening and the toroidal core rear side (5) has two feet (14) projecting in the direction of the longitudinal axis (8) of the opening, which feet are arranged offset from the two feet (14) of the toroidal core side (4).

Description

Technical FieldThe invention relates to a filter component with a windingless toroidal core, to a filter assembly with a plurality of the filter components, to a system with at least one such filter component and to a method for fastening the filter assembly or the filter component.Prior ArtWound or windingless toroidal cores are often used in filters.Wound toroidal cores often require a housing which is fastened on a fastening element, for example a printed circuit board or a base plate. Furthermore, these wound toroidal cores often require a terminal to connect the conductor to the winding of the toroidal core.Alternatively, windingless toroidal cores are used. These are particularly simple, since the conductor is simply guided through the opening of the toroidal core or the toroidal core is closed around the conductor. Thereafter, the toroidal core is fixed to the conductor. This is generally effected by casting the annular core with the conductor. However, such casting of the toroidal core with the conductor is complicated. Alternatively, there are also folding cores consisting of two hollow cylinder halves which are fastened around a conductor by pressing together. However, these clamshells are complex to manufacture and require a new clamshell for each core size.A filter component with a windingless toroidal core is known from the publication JP H07-230 915 A. In this case, two housing parts are latched to one another, including an annular core. The annular core is only inserted between the housing parts and for its part does not latch with these.Another two-shell toroidal core housing for receiving a toroidal core is known from the publication DE 694 07 728 T2. The two housing parts have corresponding projections and recesses in their connecting plane for a plug connection.Another two-shell toroidal core housing for receiving a toroidal core is known from the publication JP H08-167 524 A. In this case, the two housing parts are connected via a film hinge. After the ring core has been inserted, they are folded together and locked together.The publication JP 2014-96 538 A discloses an annular core housing for receiving two annular cores. The housing has a central receiving section for the two toroidal cores, and also two annular covers which, after the toroidal cores have been inserted, are each connected to the central receiving section and fix the toroidal cores. From the central receiving section, two stand feet project transversely to the longitudinal axis of the annular core openings. A plurality of toroidal core housings can be stacked in the direction of said longitudinal axis.SUMMARY OF THE INVENTIONIt is an object of the invention to find a filter component with a windingless toroidal core which is simple to produce, modular to use and / or easy to install.This object is achieved by a filter component according to claim 1, a filter assembly according to claim 15, a system according to claim 17 and a method according to claim 21.The snap mechanism allows easy assembly of the filter member without the need for potting the toroidal core with the conductor. In addition, the toroidal core can be fastened to a fastening element via the housing and the conductor can also be subsequently guided through the opening of the toroidal core. However, the filter component may of course also be fastened to the conductor in some cases.The fastening surface now allows the housing of the winding-less toroidal core to be fastened directly on a fastening element and no longer has to be fastened to the conductor. This avoids complicated casting or complex folding mechanisms for toroidal cores. In particular, the fact that the conductor can be guided loosely through the opening of the toroidal core in the toroidal core housing allows the filter to be already fixedly installed and the conductors to be pulled / pushed through the toroidal core opening only during assembly. This allows simpler assembly procedures for toroidal cores.A filter assembly with a plurality of filter components allows modular enlarging of the toroidal core with the same filter component by arranging these filter components one behind the other. At the same time, each filter component of the filter assembly can be individually fastened by its toroidal core housing. Thus, an assembled filter assembly can be enlarged by adding another filter member without removing the other filter members. Likewise, a filter assembly can be miniaturized by removing one of the filter components. For this purpose, only the one filter component needs to be released. This is particularly advantageous in combination with the snapping-in ring cores in the ring core housings as described above. However, the toroidal cores could also be fastened in the toroidal core housings differently, for example by the pressure of the adjoining filter component or by a clamping mechanism. The use of a housing for each toroidal core has the further advantage that no different housings have to be provided for different numbers of toroidal cores.The system has a fastening element, at least one of the described filter components or one of the described filter assemblies. The at least one filter component or the filter assembly is fastened on the fastening element. The system further comprises a conductor which is guided without winding through the opening of each annular core of the at least one filter component or of the filter assembly.The concept of fastening winding-free toroidal cores by a housing on a fastening element avoids the complicated connection of the toroidal cores to the conductor, in particular for a larger number of toroidal cores. At the same time, the system can be fully installed before the conductor is passed through the ring cores.In a particular embodiment, the first fastening surface and / or the second fastening surface have recesses for fastening means. Fastening means are preferably rivets or screws. In one embodiment, the recess is suitable both for the fastening of rivets and for the insertion of a nut for fastening a screw.In a particular embodiment, the toroidal core side has two stand recesses for receiving a respective stand, which are arranged opposite the two stand feet of the toroidal core rear side, and the toroidal core rear side has two stand recesses for receiving a respective stand, which are arranged opposite the two stand feet of the toroidal core side. Thus, the footprint of a single toroidal core housing can be increased without increasing the effective width of the toroidal core housing in a stack of toroidal core housings. At the same time, the form-fitting reception of the stand feet allows the transmission of axial forces from one toroidal core housing to the next. This stabilizes annularly assembled core housings.In a particular embodiment of a filter assembly, filter components are of identical construction. As a result, ring cores of any size can be assembled by means of a filter component type by being arranged one next to the other.In a particular embodiment of the system, the conductor is not fastened to the at least one filter component or to the filter assembly, or the conductor is loose.Brief Description of the FiguresThe invention is explained in more detail with reference to the attached figures, wherein FIG. 1 shows a first three-dimensional view of an exemplary embodiment of the component according to the invention; FIG. 2 shows a second three-dimensional view of the exemplary embodiment of the component according to the invention; FIG. 3 shows a first side view of the exemplary embodiment of an assembly according to the invention; FIG. 4 shows a second side view of the exemplary embodiment of the assembly according to the invention; FIG. 5 shows a third side view of the exemplary embodiment of the assembly according to the invention; FIG. 6 shows a fourth side view of the exemplary embodiment of the assembly according to the invention; FIG. 7 shows the section A-A of FIG. 3 of the exemplary embodiment of the assembly according to the invention; FIG. 8 shows the section B-B of FIG. 3 of the exemplary embodiment of the assembly according to the invention; FIG. 9 shows the section D-D of FIG. 4 of the exemplary embodiment of the assembly according to the invention; and FIG. 10 shows a filter with a filter assembly.WAYS OF CARRYING OUT THE INVENTIONFIGS. 1 and 2 show two three-dimensional views of an exemplary embodiment of the filter component 1 according to the invention. FIGS. 3 to 9 show different views and sections of an exemplary embodiment of the filter assembly 100 according to the invention. FIG. 10 shows a filter with a filter group 100.A filter group includes a plurality of filter members 1. The filter assembly 100 shown in FIGS. 3 to 9 has two filter components 1. However, the filter group 100 may include any other number of filter members 1. The filter group 100 can also have filter components according to the invention other than the filter components 1. However, different filter components 1 can also be used in the filter assembly 100. The filter components 1 of a filter assembly 100 are arranged one behind the other, so that they form a larger annular core with a common opening in order to guide a conductor, e.g. a cable, a (rigid) busbar or other current-carrying means through the common opening. In the filter assembly 100 shown, a first filter member 1 and a second filter member 1 are used for the filter assembly 100.The filter component 1 has an annular core 2 and an annular core housing 3.The ring core 2 is formed here as a circular straight hollow cylinder with a central opening. However, the invention is not limited to such a ring shape. Rather, any core shape with a central opening configured for winding-free passage of a conductor is possible. The central opening of the toroidal core 2 should have a straight longitudinal axis 8 which is preferably arranged perpendicular to the two sides of the toroidal core 2 having the opening. Instead of being circular, the toroidal core 2 can also have an elliptical, square, polygonal, polygonal, general or other cross-section. Preferably, it is a straight hollow cylinder, i.e. the inner and outer lateral surfaces of the hollow cylinder are perpendicular to the base surfaces. However, inclined hollow cylinders are also possible. The toroidal core 2 is closed in this exemplary embodiment. The toroidal core 2 can, however, also be designed open, that is to say there is no closed path in the toroidal core 2 which passes around the opening. The toroidal core 2 is made of a magnetic material, preferably a ferromagnetic material.The toroidal core housing 3 is a housing for the toroidal core 2, The toroidal core housing 3 is preferably made of an electrically insulating material. The toroidal core housing 3 has a toroidal core side 4, a toroidal core rear side 5 opposite the toroidal core side 4, a first fastening side 6 and a second fastening side 7. The ring core side 4 is shown in the plan view in FIG. 3 and obliquely in FIG. 1 ; the ring core rear side 5 is shown obliquely in FIG. 2. The first fastening side 6 is shown in the plan view in FIG. 5 and obliquely in FIG. 2, the second fastening side 7 is shown in the plan view in FIG. 6 and obliquely in FIG. 1, and in this exemplary embodiment the toroidal core side 4 and the toroidal core rear side 5 are arranged parallel to one another. In another exemplary embodiment, the toroidal core side 4 and the toroidal core rear side 5 could enclose an angle which, however, allows stacking of the toroidal core housings 3. Preferably, a common longitudinal axis of the openings of the ring cores 2 should thereby be achieved. In this exemplary embodiment, the fastening side 6 is arranged opposite the second fastening side 7, preferably parallel thereto. However, the second fastening side 7 can also be arranged differently or can be omitted altogether. In this exemplary embodiment, the first fastening side 6 is arranged at right angles to the toroidal core side 4 and / or to the toroidal core rear side 5. In this exemplary embodiment, the first fastening side 6 is likewise parallel to the longitudinal axis 8 of the opening of the toroidal core 2, so that when the toroidal core housing is fastened on a flat fastening element, the longitudinal axis 8 of the opening of the toroidal core 2 runs parallel to the flat fastening element (or to its fastening surface). FIG. 4 shows one of the two sides of the toroidal core housing 3, which in this exemplary embodiment form the fifth and sixth sides of a cuboid in addition to the four mentioned sides. However, the fifth and sixth sides have no function and could also be shaped differently. The height and width of the toroidal core side 4 and of the toroidal core rear side 5 and the lengths of the other four sides are greater than the diameter of the toroidal core 2. the width of the other four sides is greater than or corresponds to the thickness of the toroidal core 2, i.e. the dimension in the direction of the longitudinal axis 8 of the opening of the toroidal core 2.The first fastening side 6 of the toroidal core housing 3 has fastening means for fastening the toroidal core housing 3 to a fastening element by means of the first fastening side 6. Here, two fastening recesses 13 are provided as fastening means, which are preferably arranged at the two ends of the longer side of the first fastening side 6 and / or centrally with respect to the shorter side of the first fastening side 6. The fastening recesses 13 are designed to receive rivets and / or nuts. For this purpose, behind the fastening recesses 13 there is a cavity in which the rivet can widen behind the fastening recess. The cavity of the fastening recess 13 is alternatively or additionally designed to receive a nut, so that the toroidal core housing 3 can be screwed on. The nut can be inserted, for example, from the ring core rear side. The cavity preferably has means for preventing rotation and / or for securing a positioning of the nut. Preferably, the fastening side is configured flat in order to fasten the toroidal core housing 3 on a flat fastening element. In this exemplary embodiment, the footprint of the first fastening side 6 is enlarged by four feet 14 which extend in a protruding manner from the toroidal core side 4 and the toroidal core rear side 5 in the same plane of the first fastening side 6. This allows the footprint of the toroidal core housing 3 to be enlarged. This is particularly advantageous if only one toroidal core housing 3 or only a small number of toroidal core housings 3 is fastened.In this exemplary embodiment, two feet 14 are arranged on the ring core side 4 and two feet 14 are arranged on the ring core rear side 5. The feet 14 of the toroidal core side 4 are arranged offset with respect to the feet 14 of the toroidal core rear side 5. This can be seen well in FIGS. 5, 6 and 9. At the same time, stand recesses 15 are arranged in the ring core side 4 opposite the position of the stands of the ring core rear side 5, and stand recesses 15 are arranged in the ring core rear side 5 opposite the position of the stands of the ring core side 4. Each foot recess 5 is suitable for receiving a foot 14. Thus, two filter components 1 can be arranged with the ring core side 4 directly on the ring core rear side 5 of the second filter component 1. The stand feet 14 of the annular core side 4 of the first filter component 1 are received completely in the stand recesses 15 of the annular core rear side 5 of the second filter component 1. The feet 14 of the annular core rear side 5 of the second filter component 1 are received completely in the foot recesses 15 of the annular core side 4 of the first filter component 1 (see FIG. 5 ). Thus, the ring core side 4 of the first filter component 1 can be arranged flush with the ring core rear side 5 of the second filter component 1 over its surface. In the exemplary embodiment shown, the first fastening side 6 can have at least one projection, here two projections, which engages / engage in correspondingly shaped recesses of the fastening element in the fastened state. The protrusion or protrusions are configured such that the housing can only be mounted on the fastener in the aligned orientation. Here, this is achieved by an I-shaped projection and an X-shaped projection. However, any other shape of the projection or projections is also possible. This principle is also called poka yoke.The second fastening side 7 of the toroidal core housing 3 likewise has fastening means in order to fasten further components of the filter on the filter component 1 or the filter assembly 100. Here, two fastening recesses 20 are provided as fastening means, which are preferably arranged at the two ends of the longer side of the first fastening side 6 and / or approximately centrally with respect to the shorter of the first fastening side 6. The fastening recesses 20 are configured to receive rivets.For this purpose, behind the fastening recesses 20 there is a cavity in which the rivet can widen behind the fastening recess 20. The filter assembly 100 thus forms a fastening surface with at least four fastening points by the second fastening sides 7 of the filter components 1, so that further components can be fastened particularly stably on the filter assembly 100. At the same time, the filter components 1 of the filter assembly are stabilized by this fastening to one another. In this exemplary embodiment, the second fastening side 7 is configured to be flat. The fastening recesses 20 are arranged in corresponding projections from the second fastening side 7. In this way, a spaced-apart fastening of the further component is achieved and thus a heat transfer from the toroidal cores 2 to the further component is avoided. The second fastening side 7 is optional and not essential for the invention.The toroidal core side 4 of the toroidal core housing 3 has a recess for inserting and receiving the toroidal core 2. The shape of the recess corresponds to the projection of the toroidal core 2 onto a surface at right angles to the longitudinal axis 8 of the toroidal core (for a straight hollow cylinder, this corresponds to the cross section or the base surface of the hollow cylinder). The toroidal core housing 3 furthermore has an opening which runs from the toroidal core side 4 to the toroidal core rear side 5. In this exemplary embodiment, the longitudinal axis of the opening of the toroidal core housing 3 is identical to the longitudinal axis 8 of the opening of the toroidal core 2. In this exemplary embodiment, the cross section of the opening of the annular core housing 3 is circular. However, the cross section of the opening of the toroidal core housing 3 can also have other shapes. The shape of the opening of the toroidal core 2 preferably corresponds to that of the cross section. The recess for inserting and receiving the toroidal core 2 has an outer wall 9, a rear wall 10 and an inner wall 11. The outer wall 9 covers the outer side (here the outer surface of the hollow cylinder) of the annular core 2. The inner wall 11 covers the inner side (here inner lateral surface of the hollow cylinder) of the annular core 2. The rear wall 10 covers the rear side (here one of the base surfaces of the hollow cylinder) of the annular core 2. In this exemplary embodiment, the toroidal core housing 3, but at least the inner wall 9, the rear wall 10 and the outer wall 11, is made of an electrically insulating material. As a result, the toroidal core 2 is insulated from these three sides.The toroidal core housing 3 furthermore has a snap mechanism which is designed to open when the toroidal core 2 is introduced into the toroidal core housing 3 and to snap in when the position of the toroidal core 2 is reached. In the snapped-in state, the snap-in mechanism holds the ring core 2 in its position by form-fitting. In this exemplary embodiment, the snap mechanism is arranged in the recess of the ring core side 4. In this exemplary embodiment, the snap-in mechanism is realized by at least one snap-in lever 12. In this embodiment, four snap levers 12 are used. However, two, three, five or more snap levers 12 or other snap mechanisms could also be used. In this exemplary embodiment, the snap levers 12 are distributed over the outer periphery of the toroidal core. Alternatively, however, these could also be distributed over the inner circumference or both circumferences. Each snap lever 12 is fastened at a fulcrum in the toroidal core housing 3, advantageously to the outer wall 11. The fulcrum is preferably arranged more in the direction of the rear wall 10 than in the direction of the ring core side 2, in order to achieve a lever that is as long as possible. On the side of the lever arm arranged opposite the fulcrum, the snap lever 12 has a lever head. The lever head, in its locked position, blocks the toroidal core 2 locked in the toroidal core housing 3 and prevents its movement in the direction of the longitudinal axis of the opening and / or the normal of the toroidal core side 4. This is achieved by a sloping surface which slopes down towards the center of the toroidal core 2. As a result, the ring core 2, which abuts on the inclined surface during insertion, presses the snap levers 12 apart into an open position by the skillful orientation of the inclination of the lever head. As a result, the ring core 2 can automatically open the snap-in mechanism upon insertion. In this exemplary embodiment, bulges are provided in the outer wall in the region of the snap levers 12, which bulges allow the range of movement of the snap lever 12 from the locked position into the open position, which allows the insertion of the toroidal core 2. Alternatively, the distance between the outer wall 11 and the outer side of the toroidal core 2 could be designed to be so large that the snap levers 12 have sufficient movement clearance radially with respect to the longitudinal axis of the opening of the toroidal core housing even without bulges. Two of the four snap levers 12 are particularly well shown in section B-B in FIG. 8. The snap-in levers 12 and the rear wall 10 of the recess thus prevent a movement of the toroidal core in the direction of insertion and execution of the toroidal core 2. a movement perpendicular to this direction of movement, i.e. radially thereto, is prevented by the inner side of the toroidal core resting flush against the inner wall 9. The tolerances of the toroidal core are accommodated by means of squeezing ribs on the inner wall 9. Thus, a movement of the toroidal core 2 radially to the longitudinal axis of the inner wall is prevented by simple positive locking. Thus, the snapped-in toroidal core 2 is simple to assemble and nevertheless firmly positioned with respect to the toroidal core housing 3. On the ring core rear side 5, the rear wall 10 is recessed in the region of the snap levers 12. Thus, the snap levers 12 can be opened simultaneously, for example by a special tool, in order to remove the toroidal core 2 again from the toroidal core housing. At the same time, these openings allow a pressure to be exerted on the toroidal core 2 from the toroidal core rear side 5 in the direction of the toroidal core side 4, in order to also be able to remove the toroidal core 2 again from the toroidal core housing 3. This may be necessary if the ring core 2 has been damaged and has to be replaced.In this exemplary embodiment, the toroidal core side 4 of the toroidal core housing 3 furthermore has at least one protrusion 16, which is arranged opposite a corresponding recess 19 on the toroidal core rear side 5. In the filter component group 100, the protrusion 16 of the annular core side 4 of the first filter component now engages in the recess 19 of the annular core rear side 5 of the second filter component 1. This ensures that the filter components 1 of a filter assembly 100 can only be positioned against one another in one orientation. The choice of which of the ring core side 4 and the ring core rear side 5 now contain the projection or the corresponding recess is immaterial. Alternatively, this function could also be achieved by the stand feet 14 and the stand foot recesses 15. In this exemplary embodiment, the annular core side 4 of the filter component additionally has one or more latching elements 17 which are arranged opposite latching recesses 18 arranged on the annular core rear side 5. The latching elements 17 are designed, when two filter components 1 are pressed against one another in the correct positioning, to latch into the latching recesses 18 of the annular core rear side 5 of the second filter component 1. In the engaged state, the at least two filter components 1 of the filter assembly 100 are fastened to each other and can only be achieved by pulling the two filter components 1 apart with a force that exceeds a threshold value. Thus, a filter assembly 100 can be easily plugged together with any number of filter components 1, without having to hold the individual filter components 1 in their relative position until they are fastened on the fastening element. FIG. 9 shows a section through the filter assembly 100 through the latching elements 17 and the latching recesses 18. Preferably, two latching elements 17 are arranged on the toroidal core side 2 in the direction of the second fastening side 7 or opposite the first fastening side 6. As a result, the filter components 1 are held together in the filter assembly 100 opposite the first fastening side 6, even if no further component is fastened on the filter assembly 100 or if there is no second fastening side 7.In this exemplary embodiment, the inner wall 9 protrudes somewhat beyond the toroidal core side 4 of the toroidal core housing 3. In the region of this projection, the cone formed by the inner wall 9 narrows in diameter continuously or in a stepped manner. The ring core rear side 5 has a receiving recess in order to receive this tapered cone of the inner wall 9. The receiving recess is here likewise realized by the inner wall 9. Since the opening for the passage of a conductor in the toroidal core housing 3 is also formed by the inner wall 9, the openings of the toroidal core housings 3 are aligned with one another by the engagement of the tapered inner wall 9 on the toroidal core side 4 of the first filter component 1 with the inner wall 9 on the toroidal core rear side 5 of the second filter component 1.FIG. 10 now shows a schematic arrangement of a filter, for example an EMC filter (EMC: electromagnetic compatibility). The filter is mounted on a mounting member 102. The filter comprises an optional intermediate plate 101, a filter assembly 100 having a plurality of filter components 1, an optional further component 103 and a conductor 104. The filter assembly 100 is mounted on the intermediate plate 101 and is then mounted on the mounting member 102. However, the filter assembly 100 may also be directly fastened on the fastening element 102. The assembled filter components 1 of the filter assembly 100 are riveted to the intermediate plate 101 or to the fastening element 102. For this purpose, the rivets are guided through the two fastening recesses 13 of each filter component 1 and fastened. Alternatively, however, screws and other fastening means can also be used. Optionally, a further component 103 is fastened on the filter assembly 100. For this purpose, the further component 103 is riveted or fastened in some other way through the fastening recesses 20 of the filter components 1 of the filter assembly 100. The further component 103 can also serve only for stabilizing the filter components 1 of the filter assembly 100 with respect to one another. Thus, the filter assembly 100 can be already fastened without the conductors 104 to be filtered. The conductor or conductors 104 can finally be guided through the opening of the filter assembly 100, i.e. through the openings of the toroidal cores 2 and the toroidal core housings 3 of the filter components 1. It is no longer necessary to fasten the windingless toroidal cores 2 to the conductor 104. This eliminates the need for expensive fastenings of the windingless toroidal cores 2 to the conductor 104. At the same time, however, the windingless toroidal core 2 is fastened. The conductor 104 may be a cable or a rigid conductor rail. In the case of a rigid conductor rail, it is advantageous to fasten it likewise to the fastening element 102 or to the intermediate plate 101, with the result that the conductor rail is fixedly positioned relative to the annular cores 2. In an alternative exemplary embodiment, the filter assembly 100 can also have only one filter component 1.An advantage of the invention is that a complicated fastening of the conductor to the filter components 1 or the annular cores 2 is not necessary.Another advantage is that the assembly, the variation in size and the fastening of the filter assembly 100 are particularly simple. Depending on the necessary size of the windingless toroidal core 2, the number of filter components 1 of the filter assembly 100 is selected. For each filter component, the toroidal core 2 is inserted into the toroidal core housing 3. All filter components are plugged together (stacked), so that the annular core of the desired size is obtained. Now, only the filter assembly 100 thus assembled needs to be fastened and a conductor 104 passed through the opening of the filter assembly 100.

Claims

Filter component comprising: a winding-less magnetic toroidal core (2) having an opening; a toroidal core housing (3) in which the toroidal core (2) is fastened by a snap mechanism; wherein the filter component (1) is configured such that a conductor (104) can be guided winding-less through the opening of the toroidal core (2) fastened in the toroidal core housing (3), wherein the toroidal core housing (3) has a first fastening surface (6) for fastening the toroidal core housing (3) which is arranged parallel to a longitudinal axis (8) of the opening of the toroidal core (2), the toroidal core housing (3) has an toroidal core side (4) for inserting the toroidal core (2) and an toroidal core rear side (5) opposite the toroidal core side (4), wherein the toroidal core side (4) has two feet (14) projecting in the direction of the longitudinal axis (8) of the opening and the toroidal core rear side (5) has two feet (14) projecting in the direction of the longitudinal axis (8) of the opening, which feet are arranged offset with respect to the two feet (14) of the toroidal core side (4).Filter component according to claim 1, wherein the snap mechanism is configured such that the toroidal core (2) can be inserted into the toroidal core housing (3) in the direction of a longitudinal axis of the opening of the toroidal core (2).Filter component according to claim 1 or 2, wherein the snap mechanism comprises one or more movable levers (12) shaped such that the movable lever or levers (12) open upon pressing the toroidal core (2) against the toroidal core housing (3) and hold the toroidal core (2) after the snap-in of the movable lever or levers (12).Filter component according to claim 3, wherein the toroidal core (2) has a hollow cylindrical shape, and the movable levers (12) are shaped such that the movable levers (12) are pressed apart into an open position when the toroidal core (2) is pressed against the toroidal core housing (3).Filter component according to one of Claims 1 to 4, wherein the annular core (2) is arranged in a recess of the annular core housing (3) corresponding to the annular core (2).Filter component according to one of Claims 1 to 5, wherein the toroidal core housing (3) has an inner wall (9) which covers a wall of the toroidal core (2) in the opening thereof, and an outer wall (9) which covers the outer wall of the toroidal core (2) opposite the opening.Filter component according to one of Claims 1 to 6, wherein the toroidal core housing (3) has a second fastening surface (7) for fastening a further component (103) on the toroidal core housing (3), which is arranged parallel to the longitudinal axis (8) of the opening of the toroidal core (2).Filter component according to claim 7, wherein the first fastening surface (6) is arranged parallel to the second fastening surface (7).Filter component according to either of Claims 7 and 8, wherein the first fastening surface (6) and / or the second fastening surface (7) has recesses (13, 20) for fastening means.Filter component according to one of Claims 1 to 9, wherein the first fastening surface (6) has two or more recesses (13) for fastening means and the four projecting feet (14) have in order to enlarge the footprint of the toroidal core housing (3).Filter component according to one of Claims 1 to 10, wherein the toroidal core side (4) has two stand recesses (15) for receiving in each case one stand (14), which recesses are arranged opposite the two stand feet (14) of the toroidal core rear side (5), and the toroidal core rear side (5) has two stand recesses (15) for receiving in each case one stand (14), which recesses are arranged opposite the two stand feet (14) of the toroidal core side (4).Filter component according to one of Claims 1 to 11, wherein the toroidal core housing (3) has an toroidal core side (4) for inserting the toroidal core and an toroidal core rear side (5) opposite the toroidal core side (4), wherein the toroidal core side (4) and the toroidal core rear side (5) of the toroidal core housing (3) are formed such that, when the filter component (1) is arranged with the toroidal core side (4) following an toroidal core rear side (5) of a filter component (1) of identical construction, a movement of the two filter components (1) relative to the longitudinal axis (8) of the opening of the toroidal core (2) is prevented by form locking.Filter component according to claim 12, wherein the toroidal core side (4) and the toroidal core rear side (5) of the toroidal core housing (3) are formed such that, when the filter component (1) is arranged with the toroidal core side (4) following a toroidal core rear side (5) of a filter component (1) of identical construction, the arrangement is possible only in one positioning.Filter component according to claim 12 or 13, wherein the ring core side (4) and the ring core rear side (5) of the ring core housing (3) each have latching elements (17, 18), which, when the filter component (1) is arranged with the ring core side (4) adjoining a ring core rear side (5) of a filter component (1) of identical construction, a latching connection can be created between the filter part and the filter part of identical construction.Filter assembly comprising a plurality of filter components according to one of the preceding claims, each having an annular core (2) and an annular core housing (3), wherein each annular core housing (3) has an annular core side (4) and an annular core rear side (5) opposite the annular core side (4), wherein the plurality of filter components are arranged in a stacked manner such that the annular core side (4) of one of the filter components (1) bears against the annular core rear side (5) of an adjacent filter component (1).Filter assembly according to claim 15, wherein the filter components (1) are of identical construction.A system comprising: a fastening element (102); at least one filter component (1) according to any one of claims 1 to 14 or a filter assembly (100) according to claim 15 or 16, which are fastened on the fastening element (102); a conductor (104), which is guided in a winding-less manner through the opening of each toroidal core (2) of the at least one filter component (1) or of the filter assembly (100).The system of claim 17, wherein the conductor is not attached to the at least one filter component (1) or to the filter assembly (100).The system of claim 17 or 18, wherein the filter assembly (100) is mounted on an intermediate plate (101) and the intermediate plate (101) is mounted on the mounting member (102).The system according to any one of claims 17 to 18, wherein the at least one filter component (1) or the filter assembly (100) has recesses (13) for the fastening and the at least one filter component (1) or the filter assembly (100) is fastened by these recesses (13) to the fastening element (102) or to an intermediate plate (101) with rivets or screws.A method comprising the steps of: mounting a filter assembly (100) according to claim 15 or 16 or a filter component (1) according to any one of claims 1 to 14 on a mounting element (1); and passing a conductor through an opening of the toroidal core (2) or the toroidal cores (2) after mounting the filter assembly (100) or the filter component (1).

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