Electromagnetic compatibility filter
By using magnetic components made of different magnetic choke materials with the same shape and size, the problems of high manufacturing cost and complex assembly of EMC filters are solved, achieving low-cost and flexible magnetic ring assembly and improving manufacturing and assembly efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-08
- Publication Date
- 2026-04-10
AI Technical Summary
Existing EMC filters are expensive to manufacture and complex to assemble, have the risk of magnetic component mismatch, and require a large number of molds, resulting in low manufacturing and assembly efficiency.
At least two magnetic chokes are used, each consisting of a first component and a second component made of different magnetic choke materials, with the same shape and size. Frequency adaptation is achieved by changing the corresponding magnetic circuit length of the magnetic component in the magnetic circuit, and the magnetic component is fixed by a glue sealing process.
It significantly reduces the number of manufacturing molds, reduces the manufacturing cost of magnetic rings, avoids mismatch of magnetic components, and improves assembly efficiency and yield.
Smart Images
Figure CN224111063U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of electronic equipment, specifically, relate to a electromagnetic compatibility (EMC) filter. BACKGROUND
[0002] In the field of new energy vehicles, PTU is usually used to convert a certain current into other types of current. An EMC filter is arranged in the shell of the PTU to suppress and eliminate strong electromagnetic interference, reduce noise in the current, and ensure safe and reliable operation of the equipment.
[0003] One or more magnetic throttles (also known as "magnetic rings") are usually arranged in the EMC filter. According to the requirements for the applicable frequency range, the shape of the magnetic components constituting each magnetic ring is often different. In addition, since the magnetic throttle materials selected to constitute each magnetic ring have their own applicable filtering frequency range, in the case of using multiple magnetic rings, the magnetic rings composed of different magnetic throttle materials are usually used together to obtain the expected filtering frequency range.
[0004] For example, in an EMC filter using two magnetic rings, the magnetic components constituting one magnetic ring are respectively pressed and formed by the same magnetic throttle material and are high-temperature sintered and solidified, and then the solidified magnetic components are abutted against each other to form the required magnetic ring (i.e., the required magnetic loop is formed between the two). Considering that the sintering shrinkage rates of different magnetic throttle materials are different, and the shapes required by different components in the same magnetic ring are often different, this results in the fact that the molds required to manufacture the four magnetic components constituting the two magnetic rings cannot be shared, that is, a total of four sets of molds are required to manufacture the four magnetic components. In addition, in order to facilitate EMC debugging, the geometry of the magnetic ring used is usually designed to be consistent, so when assembling, additional attention is required to prevent mismatching (i.e., magnetic components made of the same magnetic throttle material need to be assembled together) to obtain the expected magnetic ring (made of the same magnetic throttle material).
[0005] The above process results in the need for different molds for different magnetic components, which in turn results in high manufacturing costs of the molds due to the different magnetic throttle materials used to manufacture the magnetic components and their shapes, and the large number of magnetic components required, and there is a risk of mismatching the magnetic components.
[0006] Therefore, there is a need in the art to provide an EMC filter with low manufacturing cost and flexible and simple assembly. UTILITY MODEL CONTENT
[0007] To achieve the above-mentioned purpose, the present application provides an EMC filter.
[0008] According to one embodiment of the present application, the filter comprises: at least two magnetic chokes, each of the at least two magnetic chokes comprises a first component and a second component constituting a magnetic circuit.
[0009] According to another embodiment of the present application, a magnetic circuit plane of the magnetic circuit is perpendicular to a length direction of the filter.
[0010] According to still another embodiment of the present application, the first component and the second component are both U-shaped members with two arms, and the two arms of the first component are respectively arranged to be magnetically coupled with a corresponding one of the two arms of the second component to form the magnetic circuit.
[0011] Further, the first component and the second component are both unequal-arm U-shaped members with a long arm and a short arm, and the short arm end face and the long arm end face of the first component are respectively magnetically coupled with the long arm end face and the short arm end face of the second component to form the magnetic circuit.
[0012] According to still another embodiment of the present application, the first component is an equal-arm U-shaped member, and the second component is a square-shaped member arranged between and magnetically coupled with the two arms of the first component to form the magnetic circuit.
[0013] According to another embodiment of the present application, the first component is an equal-arm U-shaped member, and the second component is an I-shaped member with an action surface, and the second component is arranged such that the action surface thereof is magnetically coupled with the arm end faces of the two arms of the first component to form the magnetic circuit.
[0014] According to still another embodiment of the present application, the first component is an unequal-arm U-shaped member with a long arm and a short arm, and the second component is an L-shaped member with a working surface and an arm end face on the same side, and the long arm end face and the short arm end face of the first component are respectively magnetically coupled with the working surface and the arm end face of the second component to form the magnetic circuit.
[0015] According to still another embodiment of the present application, a cross section of each of the magnetic chokes taken along a direction perpendicular to the length direction of the filter is polygonal, circular or elliptical.
[0016] According to another embodiment of the present application, the first component and the second component are stacked one on top of the other or placed opposite each other in a plane of the magnetic circuit perpendicular to the length direction of the filter.
[0017] The EMC filter provided by the present application can significantly reduce the number of manufacturing molds required, reduce the manufacturing cost of the magnetic ring, avoid the problem of mismatching of magnetic components belonging to different magnetic rings, reduce the complexity of assembly, and shorten the time required for assembly. BRIEF DESCRIPTION OF DRAWINGS
[0018] The drawings of the present application show several specific structures of the EMC filter of the present application by way of example, but they are only exemplary and are not intended to limit them to the structures shown. In the drawings, the same or similar reference numerals are used to refer to the same or similar features. In the drawings:
[0019] Figure 1 is a perspective view of the EMC filter according to the present application.
[0020] Figure 2 is a view similar to Figure 1 , in which the arrangement of the magnetic ring in the EMC filter is shown in color solid lines, while the rest is shown in black dashed lines.
[0021] Figure 3 is Figure 2 one of the three magnetic rings used in the EMC filter shown in
[0022] Figure 4A and Figure 4B are respectively Figure 3 left side exploded view and exploded perspective view of one of the magnetic rings shown in
[0023] Figure 5A and Figure 5B are respectively Figure 4A and Figure 4B left side exploded view and exploded perspective view of an alternative embodiment of the magnetic ring shown in
[0024] Figure 6A and Figure 6B are respectively Figure 3 left side exploded view and exploded perspective view of another embodiment of one of the magnetic rings shown in
[0025] Figure 7A and Figure 7B are respectively Figure 3 left side exploded view and exploded perspective view of yet another embodiment of one of the magnetic rings shown in
[0026] Figure 8A and Figure 8B are respectivelyFigure 3 A left side exploded view and an exploded perspective view of a further embodiment of one of the magnetic rings shown in DETAILED DESCRIPTION
[0027] The specific structure of the EMC filter of the present application will be described below with reference to the accompanying drawings.
[0028] Referring to Figures 1-3 , Figure 1 is a perspective view of the EMC filter of the present application, Figure 2 is a view similar to Figure 1 , in which the magnetic choke (i.e., the magnetic ring) is shown in its installed condition in colored solid lines, while the remaining structure is shown in black dashed lines, Figure 3 the three magnetic rings used in the EMC filter of Figure 2 are shown individually in their assembled condition.
[0029] As shown in Figure 3 , the three magnetic rings 100 are arranged along the length direction of the EMC filter (x direction shown in Figure 1 and Figure 3 ), and each forms a magnetic circuit in a plane perpendicular to the length direction (i.e., the y-z plane defined by the y axis and the z axis, hereinafter referred to as the "magnetic circuit plane"). As mentioned previously, for the convenience of EMC debugging, the geometry of the magnetic rings used is usually set to be uniform.
[0030] Referring to Figure 4A and Figure 4B , which show a left side exploded view and an exploded perspective view, respectively, of one of the three magnetic rings shown in Figure 3 . The magnetic ring 100 comprises two magnetic components, i.e., a first magnetic component 101 and a second magnetic component 102. Among them, the first magnetic component 101 is in the form of an equal-arm U-shaped piece, which defines arm end faces 101A and 101B to be in abutment (close contact) with the second magnetic component 102. The so-called "equal-arm U-shaped piece" herein refers to a U-shaped component having two arms of equal length in a cross section taken in the y-z plane of the EMC filter. Preferably, the magnetic flux area (i.e., the cross-sectional area taken perpendicular to the magnetic field strength direction in the case of forming a magnetic circuit) at each location of the U-shaped piece is substantially equal.
[0031] The second magnetic component 102 is an I-shaped piece in the shape of a cuboid, which defines an action surface 102A to be cooperated with the first magnetic component 101. The action surface 102A can be any one of the four faces with larger area in the cuboid. After the selected magnetic flux throttling materials are respectively press-formed and high-temperature sintered to solidify to form the first magnetic component 101 and the second magnetic component 102, the arm end faces 101A and 101B of the first magnetic component 101 can be abutted with the working surface 102A of the second magnetic component 102 to form the required magnetic ring, thereby forming a magnetic loop. Preferably, the magnetic flux area of the second magnetic component 102 is substantially equal to the magnetic flux area of the first magnetic component 101.
[0032] In the prior art, each magnetic ring 100 is made of the same kind of magnetic flux throttling material, and at least one of the three magnetic rings 100 is made of a magnetic flux throttling material different from the remaining magnetic rings. For example, Figure 3 One of the three magnetic rings 100 shown in FIG. 1 is made of material A, and the remaining two magnetic rings are made of material B. Alternatively, two of the three magnetic rings 100 are made of material A, and the other is made of material B. Regarding the selection of materials A and B, the skilled person can select according to the requirements of the target EMC filter for the applicable frequency range. Generally, a material with good high-frequency magnetic flux throttling effect and a material with good low-frequency magnetic flux throttling effect can be selected as the above-mentioned magnetic flux throttling material, for example, T3K of Dongci matched with T10K. Of course, the present application is not limited thereto, and the magnetic flux throttling material can also be selected from other similar models of materials from other manufacturers.
[0033] As described above, although the shapes of the first magnetic component 101 and the second magnetic component 102 in different magnetic rings 100 are the same, the number of required molds is relatively large due to the different magnetic flux throttling materials used. In the above embodiment, four molds are required to manufacture the corresponding first magnetic component 101 and second magnetic component 102 of the three magnetic rings 100. And during assembly, attention needs to be paid to assembling the first magnetic component 101 and the second magnetic component 102 made of the same magnetic flux throttling material in the same accommodating space of the EMC filter to form the magnetic ring. Obviously, the risk of mismatch during assembly is always present.
[0034] In order to solve the above problems, the present application makes certain improvements.
[0035] In the present application, all the first magnetic components 101 in the three magnetic rings 100 are made of the same magnetic flux constriction material (e.g. material A), while all the magnetic components 102 are made of another magnetic flux constriction material (e.g. material B) different from the former. In other words, each magnetic ring 100 is composed of a first magnetic component 101 and a second magnetic component 102 made of different magnetic flux constriction materials respectively. This is in contrast to the prior art which uses the same magnetic flux constriction material to form a magnetic ring. Thus, during assembly, one does not need to pay attention to the magnetic flux constriction material forming the magnetic components, but only needs to pay attention to the shape of the magnetic components to complete the assembly, thereby avoiding the problem of mismatch. This completely eliminates the risk of mismatch in the case where the first magnetic component and the second magnetic component adopt different shapes, ensuring the yield rate and greatly improving the assembly efficiency.
[0036] For a magnetic ring (magnetic loop) composed of two magnetic components, according to the requirements for the applicable frequency range, the frequency adaptation can be achieved by changing the corresponding magnetic path length of the two magnetic components in the magnetic loop. In other words, the corresponding magnetic path length of the two magnetic components can be changed by changing the shape of the two magnetic components to change the way they constitute the magnetic ring. Furthermore, considering the manufacturing cost, the shape and size of the first magnetic component and the second magnetic component in each magnetic ring are usually configured to be the same as each other.
[0037] As shown in Figure 4A and Figure 4B , the first magnetic component 101 is in the form of an equal-arm U-shaped piece, and the magnetic component 102 is in the form of an I-shaped piece. The arm end faces 101A and 101B of the first magnetic component 101 are respectively configured to abut against the working face 102A of the magnetic component 102. Moreover, the width (i.e. the size along the y direction of the EMC filter shown in Figure 3 ) of the first magnetic component 101 and the second magnetic component 102 is approximately equal. Moreover, the height (i.e. the size along the z direction of the EMC filter shown in Figure 3 ) of the magnetic component 102 is approximately equal to the width of a single arm of the first magnetic component 101, so that the size of the magnetic flux cross section of the entire magnetic loop is approximately constant.
[0038] Figure 5A and Figure 5B shows Figure 4A and Figure 4B shows a limiting case of the magnetic ring shown in Figure 4A and Figure 4B , the difference between the two embodiments is that, in the embodiment shown in Figure 5A and Figure 5BIn the illustrated embodiment, the width of the second magnetic component 112 of the magnetic ring 110 is substantially equal to the width between the two arms of the first magnetic component 111. In other words, the working face 111A of the first magnetic component 111 to be brought into abutment with the second magnetic component 112 (which plays the same role as the arm end face in the previous embodiment, only one side of which is shown) is provided on the side of the two arms of the first magnetic component 111 that face each other. The working face 112A of the second magnetic component 112 (only one side of which is shown) is provided on each of the opposite sides to be brought into abutment with the first magnetic component 111. In view of the formation of the magnetic circuit, in general, the second magnetic component 112 needs to be fitted in an interference fit between the two arms of the first magnetic component 111 to achieve abutment. Figure 7B Figure 7B In view of the formation of the magnetic circuit, in general, the second magnetic component 112 needs to be fitted in an interference fit between the two arms of the first magnetic component 111 to achieve abutment.
[0039] In Figure 6A and Figure 6B are respectively shown a left side exploded view and an exploded perspective view of another embodiment of one of the magnetic rings used in the EMC filter of the present application. In Figure 6A and Figure 6B the illustrated embodiment, the magnetic ring 120 comprises a first magnetic component 121 and a second magnetic component 122. The first magnetic component 121 is in the form of an unequal-arm U-shaped piece and defines a long arm having an arm end face 121A and a short arm having an arm end face 121B. By unequal-arm U-shaped piece, it is meant herein a U-shaped piece having two arms of unequal length in a cross-section taken in the y-z plane of the EMC filter. Preferably, the magnetic flux area (i.e. the cross-sectional area taken perpendicular to the magnetic field intensity direction in the case of a magnetic circuit) is substantially equal throughout the U-shaped piece.
[0040] The second magnetic component 122 is in the form of an L-shaped piece defining an arm to be brought into abutment with the first magnetic component 121 and a working face 122A. The arm defines an arm end face 122B to cooperate with the first magnetic component 121. Therein, the working face 122A and the arm end face 122B are located on the same side of the second magnetic component 122 so as to be able to simultaneously abut against the first magnetic component 121. As Figure 6A and 6B shown in
[0041] Figure 7A and Figure 7B are respectively shown a left side exploded view and an exploded perspective view of another embodiment of one of the magnetic rings used in the EMC filter of the present application.
[0042] Unlike the previously shown embodiments, Figure 7A and Figure 7B The magnetic ring 130 shown in Fig. 1 comprises a first magnetic component 131 and a second magnetic component 132, both in the form of unequal-arm U-shaped pieces. The first magnetic component 131 defines a short arm with an arm end face 131 A and a long arm with an arm end face 131 B, while the second magnetic component 132 defines a long arm with an arm end face 132A and a short arm with an arm end face 132B. Thereby, the magnetic loop is formed by configuring the arm end face 131 A and the arm end face 131 B of the first magnetic component 131 for abutment with the arm end face 132A and the arm end face 132B, respectively, of the second magnetic component 132.
[0043] Although Figure 7A and Figure 7B The two magnetic components are described in Figs. 1 to 3 as being in the form of unequal-arm U-shaped pieces, but the application is not limited thereto, as the skilled person will understand that they can equally be configured as mutually matching equal-arm U-shaped pieces.
[0044] Figure 8A and Figure 8B respectively show a further embodiment of one of the magnetic rings used in the EMC filter of the application. In Figure 8A and Figure 8B The two magnetic components 141 and 142 constituting the magnetic ring 140 shown in Fig. 4 are structurally identical, i.e. both are in the form of L-shaped pieces and define mutually interacting wall end faces 141 A, 142B and working faces 141 B, 142A, respectively. Thereby, the magnetic loop is formed by configuring the wall end face 141 A and the working face 141 B of the first magnetic component 141 for abutment with the working face 142A and the wall end face 142B, respectively, of the second magnetic component 142.
[0045] Figures 4A-8B respectively show several embodiments of one of the magnetic rings used in the EMC filter of the application. The main difference between them is only in the respective magnetic path lengths of the two magnetic components in the magnetic loop formed by the single magnetic ring. Based on the requirements on the applicable frequency range of the EMC filter to be obtained, the skilled person can select different magnetic ring materials and determine the final matching shapes of the two magnetic components, i.e. determine the magnetic path lengths of the two magnetic components in the same magnetic ring. Then, the magnetic ring is manufactured based on the selected magnetic ring material and the final shapes of the magnetic components.
[0046] Although the cross-sections of the magnetic rings used in the EMC filter of the application in the y-z plane are depicted as rectangular in the attached drawings, the application is not limited thereto, as they can equally be in other shapes, such as other polygons, circles, ellipses, etc. Thereby, the shapes of the required magnetic components can equally be arc-shaped, instead of polygonal as shown. The shape of the cross-section of the magnetic ring can depend on the respective shape of the accommodation space formed in the housing of the EMC filter in which it is accommodated.
[0047] Furthermore, although the magnetic components forming the magnetic ring are depicted as being stacked vertically in the orientation of the attached drawings, the present application is not limited thereto, and the two magnetic components can also be arranged in other ways, such as being arranged side by side.
[0048] After the desired magnetic ring is obtained, the final product of the EMC filter can be obtained by sequentially placing the two magnetic components in the same accommodating space of the housing of the EMC filter, and then pouring glue to fix by the glue sealing process.
[0049] Although the embodiments of the present application have been described with reference to the drawings, various modifications can be made to the above-described embodiments without departing from the scope defined by the appended claims, as will be apparent to those skilled in the art. The above-described embodiments are provided only as examples to illustrate the technical solutions of the present application, and are not intended to limit the scope of protection of the present application. The features or elements described in one embodiment can be combined into another embodiment, unless they are contradictory to the features or elements already present in another embodiment. Furthermore, the specific expressions of features in the appended claims and the possible use of reference signs are not intended to limit the scope of protection.
Claims
1. An electromagnetic compatibility filter, characterized by, The filter comprises: at least two magnetic throttles (100, 110, 120, 130, 140), each of the at least two magnetic throttles comprising a first part (101, 111, 121, 131, 141) and a second part (102, 112, 122, 132, 142) constituting a magnetic circuit, wherein the first parts of the at least two magnetic throttles are constituted by a first magnetic throttle material and have the same shape and size, wherein the second parts of the at least two magnetic throttles are constituted by a second magnetic throttle material different from the first magnetic throttle material and have the same shape and size, and wherein the first part and the second part of each of the magnetic throttles constitute a section of the magnetic circuit, respectively.
2. The electromagnetic compatibility filter of claim 1, wherein, A magnetic circuit plane of the magnetic circuit is perpendicular to a length direction of the filter.
3. The electromagnetic compatibility filter of claim 2, wherein, Respective magnetic path lengths of the first part and the second part in the magnetic circuit can be designed and selected according to specific application scenarios.
4. The electromagnetic compatibility filter according to any one of claims 1-3, characterized in that, The first part and the second part are both U-shaped members with two arms, and the two arms of the first part are respectively arranged to be magnetically coupled with a corresponding one of the two arms of the second part to form the magnetic circuit.
5. The electromagnetic compatibility filter of claim 4, wherein, The first part and the second part are both unequal-arm U-shaped members with a long arm and a short arm, and a short arm end surface (131A) and a long arm end surface (131B) of the first part are respectively magnetically coupled with a long arm end surface (132A) and a short arm end surface (132B) of the second part to form the magnetic circuit.
6. The electromagnetic compatibility filter of any one of claims 1-3, wherein, The first part is an equal-arm U-shaped member, and the second part is a square-shaped member arranged between and magnetically coupled with the two arms of the first part to form the magnetic circuit.
7. The electromagnetic compatibility filter of any one of claims 1-3, wherein, The first part is an equal-arm U-shaped member, and the second part is an I-shaped member with an action surface (102A), and the second part is arranged such that its action surface is magnetically coupled with arm end surfaces (101A, 101B) of the two arms of the first part to form the magnetic circuit.
8. The electromagnetic compatibility filter of any one of claims 1-3, wherein, The first part is an unequal-arm U-shaped member with a long arm and a short arm, and the second part is an L-shaped member with a working surface and an arm end surface on the same side, and a long arm end surface (121A) and a short arm end surface (121B) of the first part are respectively magnetically coupled with the working surface (122A) and the arm end surface (122B) of the second part to form the magnetic circuit.
9. The electromagnetic compatibility filter of any one of claims 1-3, wherein, A cross section of each of the magnetic throttles taken along a direction perpendicular to a length direction of the filter is polygonal, circular, or elliptical.
10. The electromagnetic compatibility filter of any one of claims 1-3, wherein, In a magnetic circuit plane perpendicular to the length direction of the filter, the first part and the second part are stacked up and down or placed side by side.