Filter, power electronic unit, and electric vehicle

Abstract

The utility model discloses a filter, a power electronic unit and an electric vehicle. The filter comprises an inductance component, and the inductance component comprises a magnetic core. The preformed shell is provided with a closed inner space used for containing the magnetic core, and the magnetic core and the preformed shell are combined to form a magnetic core wrapping piece; the magnetic core wrapping piece is fixed in the filter through the packaging structure, and the packaging structure is formed by applying a first material to the magnetic core wrapping piece and curing the first material on the magnetic core wrapping piece. The utility model provides a packaging structure capable of ensuring the performance of a filter.

Description

Technical Field

[0001] This application belongs to the field of filter device packaging, and more specifically relates to a filter. This application also claims a power electronic unit including the filter and an electric vehicle including the filter or the power electronic unit. Background Art

[0002] Filters are widely used in the power electronic unit (PEU) of new energy vehicles, and they can remove unwanted components in signals to reduce interference. Inductive filters include inductive components. The magnetic core is a key filtering component in the inductive component, and the magnitude of its magnetic induction determines its ability to filter noise. The fixation of the magnetic core depends on the design of the filter in the container. Some designs have corresponding fixing points or structures in the container for fixation, such as fixing with screws through a metal pressing plate, while some directly pot the bare magnetic core into the container with a material. After the material is cured by heat, the reliable fixation of the magnetic core is achieved by relying on the excellent mechanical properties of the material. The former fixation method increases the complexity of the container structure, the number of parts, and the mold opening cost, etc.; the latter fixation method is simple and reliable for the magnetic core fixation, but the material will have a large shrinkage after curing, and the material itself has a high hardness. Therefore, stress is generated inside the magnetic core under the action of the shrinkage force, and then the inverse magnetostrictive effect is generated, resulting in a decrease in the magnetic permeability of the magnetic material of the magnetic core and a decrease in the magnetic induction, affecting the filtering effect. Summary of the Utility Model

[0003] One aspect of this application is to provide a filter that ensures the filtering performance of the magnetic core in the way of fixing the magnetic core with potting material.

[0004] The filter involved in this application includes

[0005] An inductive component, the inductive component includes a magnetic core;

[0006] A preformed housing, the preformed housing has a closed internal space for receiving the magnetic core, and the magnetic core and the preformed housing form a magnetic core covering member; and

[0007] A packaging structure, the magnetic core covering member is fixed in the filter via the packaging structure, and the packaging structure is formed by applying a first material to the magnetic core covering member and curing it.

[0008] In an embodiment of the filter involved in this application, there is a gap between the internal space and the magnetic core, and a second material is filled in the gap to fix the magnetic core and the internal space.

[0009] In an embodiment of the filter related to the present application, the preformed housing includes a first part as the main body and a second part as the cover. The first part and the second part are configured to snap together with each other. The first part is further configured to have a boss provided at the bottom of the main body, such that the magnetic core is supported by the boss after being placed into the main body, so that there is a gap between the magnetic core and the bottom.

[0010] In an embodiment of the filter related to the present application, the preformed housing is made of a plastic material.

[0011] In an embodiment of the filter related to the present application, the first material is epoxy resin; the second material is silica gel.

[0012] In an embodiment of the filter related to the present application, the magnetic core is configured as a first annular structure, the internal space is configured as a second annular structure, and the first annular structure and the second annular structure are nested.

[0013] In an embodiment of the filter related to the present application, the first part includes a first snap portion located on the outer ring of the second annular structure, the second part includes a second snap portion located on the outer ring, a positioning groove is provided on one of the first snap portion and the second snap portion, a snap ring is provided on the other, and the first snap portion is snapped together with the second snap portion by fitting the snap ring into the positioning groove.

[0014] In an embodiment of the filter related to the present application, the first part includes a recessed portion located on the inner ring of the second annular structure; the second part includes a protruding portion located on the inner ring; the recessed portion and the protruding portion abut against each other; the inductive component further includes a pair of busbars, and after the recessed portion and the protruding portion abut against each other, a pair of cavities are defined within the inner ring for the pair of busbars to pass through respectively.

[0015] Another aspect related to the present application is to provide a power electronic unit, which includes a housing, and the filter and capacitor of any one of the above embodiments are arranged within the housing.

[0016] Still another aspect related to the present application is to provide an electric vehicle, which includes the filter of any one of the above embodiments or the power electronic unit of any one of the above embodiments.

[0017] This application provides a preformed housing to be combined with a magnetic core to form a magnetic core encapsulation. The preformed housing can resist most of the shrinkage force during the curing of the encapsulating material, thereby protecting the magnetic core within the preformed housing. The preformed housing blocks the encapsulating material and the magnetic core. It is formed before the application of the encapsulating material and houses the magnetic core, alleviating the decrease in inductance caused by the magnetostrictive inverse effect due to external forces on the magnetic core, thus ensuring that the magnetic core plays a filtering role.

[0018] A certain gap is left between the preformed housing and the magnetic core to be filled with other materials. On the one hand, it fixes the magnetic core within the preformed housing, and on the other hand, it provides stress-absorbing protection for the magnetic core. The preformed housing uses a material with high strength that can resist most of the shrinkage force during the curing of the encapsulating material. The filling material between the preformed housing and the magnetic core uses a material with a small shrinkage rate, low stress, and can maintain soft elasticity within a wide temperature range. This application provides double protection for the magnetic core.

[0019] This application also provides a power electronic unit integrated with a filter and a capacitor, and an electric vehicle including the above filter or the above power electronic unit. The power electronic unit and the electric vehicle have the same above-mentioned beneficial effects as the filter and the improvements in the respective product performances of the power electronic unit and the electric vehicle brought about by these beneficial effects.

[0020] Through the following detailed description with reference to the accompanying drawings, other aspects and features of this application become apparent. However, it should be understood that the drawings are designed only for the purpose of explanation and not as a limitation of the scope of this application, as it should be referred to the appended claims. It should also be understood that the drawings are only intended to conceptually illustrate the structures and processes described herein, and unless otherwise indicated, the drawings are not necessarily drawn to scale. Description of the Drawings

[0021] Referring to the following detailed description of the specific embodiments in conjunction with the accompanying drawings, this application will be more fully understood. The same reference numerals in the drawings always refer to the same elements in the views. Among them:

[0022] Figure 1 is a schematic diagram of an embodiment of the filter related to this application;

[0023] Figure 2 is Figure 1 an exploded schematic diagram of an embodiment of the magnetic core encapsulation in the filter in ;

[0024] Figure 3 is a cross-sectional view of an embodiment of the magnetic core encapsulation;

[0025] Figure 4 is Figure 3 an enlarged view of the A circle in ; and

[0026] Figure 5 This is a simplified view of an embodiment of the power electronic unit related to the present application. Detailed implementation manners

[0027] To help those skilled in the art accurately understand the subject matter claimed in the present application, the following will describe in detail the specific implementation manners of the present application with reference to the accompanying drawings.

[0028] Figure 1 This is a schematic diagram of an embodiment of the filter related to the present application. For the sake of clear illustration, Figure 1 some components of the filter and related specific structures are omitted, and only the filter structure related to the present application is shown. The filter of the present application is an EMC filter with an inductance configuration, such as an LC filter or a CLC filter. The filter includes a container 10, an inductance component 12, a preformed housing 14, and a packaging structure 16. The inductance component 12 includes a magnetic core (not shown) and a bus bar 18. In the illustrated embodiment, the bus bar 18 is a pair of copper bars. The preformed housing 14 is a prefabricated part and is used to cover the magnetic core. The packaging structure 16 is formed by a first material 20. The first material 20 is applied to the container 10 and forms the packaging structure 16 after curing. In the illustrated embodiment, the container 10 is simply schematically shown. The container 10 can be a filter housing / mold or a filter outer envelope boundary, which will be described in detail below.

[0029] The preformed housing 14 and the magnetic core are combined into a magnetic core covering member. To completely surround the magnetic core, the preformed housing 14 has a closed internal space, and the magnetic core is received in the internal space. Figure 2 This is an exploded schematic diagram of an embodiment of the magnetic core covering member, and the magnetic core 24 is shown. In one embodiment, the magnetic core 24 is a ferrite magnetic core. In another embodiment, the magnetic core 24 is a ring structure as shown, and is a ring structure presenting as a substantially rectangular shape, and this ring structure is the first ring structure 26. The preformed housing 14 includes two parts, namely a first part 28 as the main body 32 and a second part 30 as the cover 34. The first part 28 is open, the magnetic core 24 is placed into the first part 28, and then the second part 30 is snapped onto the first part 28 to enclose the magnetic core 24 in the internal space. Corresponding to the magnetic core structure, the internal space is configured as a second ring structure 36. When the magnetic core 24 is placed and the internal space is closed, the first ring structure 26 (magnetic core) and the second ring structure 36 (internal space) are nested, and the magnetic core is surrounded in all directions, thereby forming a magnetic core covering member. Combining Figure 1-2, the magnetic core 24 is surrounded by the preformed housing 14 both circumferentially and axially along the extending direction of the bus bar 18. The magnetic core coating 22 is further encapsulated as an integral part, and such a structure is different from the traditional encapsulation structure that directly fixes the bare magnetic core. After the internal space is closed, a pair of bus bars 18 pass through a pair of cavities 38 inside the inner ring of the second annular structure 36.

[0030] Figure 3 A cross-sectional view of the magnetic core coating 22 is shown to more clearly illustrate the interior of the preformed housing. There is a gap between the interior of the preformed housing 14 and the magnetic core 24, and the second material 40 is filled in the gap so that the magnetic core 24 is fixed in the internal space. The volume of the internal space can be set to be slightly larger than the volume of the magnetic core 24, so as to reserve a filling gap. The first material will be applied to the outside of the preformed housing 14, and the second material 40 is filled between the interior of the preformed housing 14, that is, the internal space and the magnetic core 24. The preformed housing 14 can resist most of the shrinkage forces generated after the first material is cured, and the second material 40 can absorb a small part of the stress generated by the shrinkage of the first material on the preformed housing 14. In one embodiment, the preformed housing 14 is made of a plastic material, such as but not limited to PPS (polyphenylene sulfide), ABS (acrylonitrile-styrene-butadiene copolymer), PP (polypropylene), etc. In another embodiment, the first material is, for example, epoxy resin. In yet another embodiment, the second material 40 is, for example, silica gel. The plastic material has high strength, so it can resist the shrinkage forces generated by the curing of the epoxy resin in the encapsulation structure. At the same time, silica gel has a certain elasticity, and it can absorb the stress from the preformed housing (plastic material) by deforming.

[0031] The size of the gap is controlled by design. On the one hand, the magnetic core 24 is reliably fixed in the internal space through the filling of the gap. On the other hand, the filling amount of the second material 40 is sufficient to replace the magnetic core to absorb stress, so that the magnetic core 24 is not affected by stress. This is achieved by completely coating the magnetic core 24 with the second material 40. Continue to refer to Figure 3, the second material 40 is not only filled in the circumferential direction of the magnetic core 24, i.e., on the outer ring 42 and the inner ring 44 of the first annular structure, but also filled in the axial direction of the magnetic core 24. In the illustrated embodiment, in the axial direction of the magnetic core 24, on the left side of the first part 28 as shown in the figure, i.e., on the bottom 46 of the main body during assembly, a boss 48 is provided, so that after the magnetic core 24 contacts the boss 48, there is a gap between the magnetic core 24 and the left side of the first part 28. During assembly, the main body is located below. If the boss is not provided, after the magnetic core is placed into the main body and directly contacts the main body, the filling of the second material between the bottom of the magnetic core and the bottom of the main body will be missing. By providing the boss 48, after the magnetic core 24 is placed into the main body and contacts and is supported by the boss 48, a gap for filling the second material 40 is left. In one embodiment, there can be multiple bosses 48 and they are symmetrically arranged. For example, four bosses are arranged at equal angular intervals circumferentially within the main body.

[0032] Combined with Figure 2 - Figure 3 , the first part 28 is provided with a recess 54 on the inner ring 52 of the second annular structure. Correspondingly, the second part 30 is provided with a protrusion 56 on the inner ring 52. When the first part 28 and the second part 30 are snapped together, the recess 54 and the protrusion 56 are in contact with each other.

[0033] Refer to Figure 4 In the enlarged view, the first part 28 is provided with a first engaging portion 58 on the outer ring 50 of the second annular structure. Correspondingly, the second part 30 is provided with a second engaging portion 60 on the outer ring 50. Among them, the first engaging portion 58 is provided with a positioning groove 62, and the second engaging portion 60 is provided with a snap ring 64 that cooperates with the positioning groove 62. When the first engaging portion 58 and the second engaging portion 60 are combined, the snap ring 64 enters the positioning groove 62, so that the first engaging portion 58 and the second engaging portion 60 are snapped together with each other. In another embodiment, the settings of the positioning groove and the snap ring are interchanged, the first engaging portion is provided with a snap ring, and the second engaging portion is provided with a positioning groove. In still another embodiment, the positioning groove and the snap ring can be not provided, and the first engaging portion and the second engaging portion are in an interference fit. The connection manner between the first engaging portion and the second engaging portion can also be achieved by other means that those skilled in the art can think of.

[0034] The assembly process of the magnetic core cover includes: placing the main body with the opening facing upward - putting in the magnetic core - filling silicone (the second material) - buckling the cover. Then the magnetic core cover is fixed into the filter. Return to Figure 1, the assembly of the magnetic core and the preformed housing 14, i.e., the magnetic core wrapper, is placed inside the container 10. A pair of busbars 18 respectively pass through the corresponding cavities and are fixed inside the container 10. Subsequently, epoxy resin (the first material 20) is poured into the container so that the magnetic core wrapper is encapsulated in the epoxy resin. After the pouring process is completed, the entire encapsulated body is placed in a hot air oven for curing until it cools down, and the epoxy resin forms the encapsulation structure 16. When the filter is a single filtering device, the container is the housing / mold of the filter. When the filter is part of a more complex device that has other functions in addition to filtering, the container is the outer envelope boundary for the filter within the device, and the filter is within the envelope boundary. Figure 5 This is a simplified view of an embodiment of the power electronic unit related to this application. The power electronic unit 66 has a housing 68, and a filter 72 and a capacitor 70 for electrical energy storage (such as a DC-link capacitor) are arranged inside the housing 68. The two are installed together, having the advantages of high integration, low cost, simplified assembly process, and space saving. The filter structure of any of the above embodiments is arranged at the filter side inside the housing. In one embodiment, the power electronic unit is, for example, an inverter assembly.

[0035] This application also relates to an electric vehicle, which includes the filter of any of the above embodiments or the power electronic unit of any of the above embodiments.

[0036] Although specific embodiments of this application have been shown and described in detail to illustrate the principles of this application, it should be understood that this application can be implemented in other ways without departing from such principles.

Claims

1. A filter, characterized in that include: An inductive component (12), the inductive component (12) comprising a magnetic core (24); A preformed shell (14), the preformed shell (14) having a closed internal space for accommodating the magnetic core (24), the magnetic core (24) and the preformed shell (14) being combined into a magnetic core covering (22); and A packaging structure (16), wherein the magnetic core covering (22) is fixed in the filter via the packaging structure (16), and the packaging structure (16) is formed by applying a first material (20) to the magnetic core covering (22) and then curing the material.

2. The filter according to claim 1, characterized in that: A gap is provided between the inner space and the magnetic core (24), and a second material (40) is filled in the gap to fix the magnetic core (24) and the inner space.

3. The filter according to claim 1, characterized in that: The preformed shell (14) includes a first part (28) as a main body (32) and a second part (30) as a cover (34), wherein the first part (28) and the second part (30) are configured to be engaged with each other, and the first part (28) is further configured to be provided with a boss (48) at the bottom (46) of the main body (32), so that the magnetic core (24) is supported by the boss (48) after being placed in the main body (32), thereby providing a gap between the magnetic core (24) and the bottom (46).

4. The filter according to claim 1, characterized in that: The preformed shell (14) is made of plastic material.

5. The filter according to claim 2, characterized in that: The first material (20) is epoxy resin; the second material (40) is silicone.

6. The filter according to claim 3, characterized in that: The magnetic core (24) is configured as a first annular structure (26), the internal space is configured as a second annular structure (36), and the first annular structure (26) and the second annular structure (36) are nested.

7. The filter according to claim 6, characterized in that: The first part (28) includes a first clamping portion (58) located on an outer ring (50) of the second annular structure (36); the second part (30) includes a second clamping portion (60) located on the outer ring (50); one of the first clamping portion (58) and the second clamping portion (60) is provided with a positioning groove (62), and the other is provided with a clamping ring (64); the first clamping portion (58) is fitted into the positioning groove (62) through the clamping ring (64) to engage with the second clamping portion (60).

8. The filter according to claim 6, characterized in that: The first portion (28) includes a recessed portion (54) located on an inner ring (52) of the second annular structure (36); the second portion (30) includes a protruding portion (56) located on the inner ring (52); the recessed portion (54) and the protruding portion (56) abut against each other; the inductor component (12) further includes a pair of bus bars (18), and after the recessed portion (54) and the protruding portion (56) abut against each other, a pair of cavities (38) are defined in the inner ring (52) for allowing the pair of bus bars (18) to pass through respectively.

9. A power electronic unit, comprising a housing (68), characterized in that A filter (72) and a capacitor (70) according to any one of Claims 1 to 8 are arranged in the housing (68).

10. An electric vehicle, characterized in that The method comprises a filter according to any one of claims 1 to 8 or a power electronic unit according to claim 9.

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