Current transformer

Abstract

The current transformer comprises a framework, a winding, a first magnetic core, a second magnetic core, a first terminal and a second terminal, the framework comprises a first side part, a second side part and a connecting part, the connecting part is of a hollow cylinder structure, and the first side part and the second side part are integrally connected to the two ends of the connecting part respectively; the winding is wound on the outer wall of the connecting part; the first terminal and the second terminal are respectively connected to the first side part and the second side part and are respectively and electrically connected with the winding; the first magnetic core and the second magnetic core are each of a U-shaped blade structure, openings of the U-shaped blade structures of the first magnetic core and the second magnetic core are oppositely connected to the framework, the first ends of the U-shaped blade structures of the first magnetic core and the second magnetic core are connected into an inner cavity of the connecting part, and the second ends of the U-shaped blade structures of the first magnetic core and the second magnetic core are connected into an outer cavity of the connecting part. And the second ends of the U-shaped blade structures of the first magnetic core and the second magnetic core are mutually connected above the winding. According to the current transformer provided by the invention, the loss of the magnetic core can be reduced, and the EMC effect of a product can be enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of current transformers, and in particular to a current transformer. Background Art

[0002] The mainstream current transformers now use EE type cores, EF type cores or EP type cores and corresponding frames. These current transformers have the following problems:

[0003] (1) During use, there is a serious loss problem. When the magnetic core is in an alternating magnetic field, especially when the drive transformer works in a high-frequency environment, the hysteresis loss and eddy current loss will be more serious;

[0004] (2) These cores may be subjected to various mechanical stresses during manufacturing, transportation and use. If the mechanical strength is insufficient, the cores are prone to cracking, thus affecting the performance and reliability of the transformer.

[0005] (3) The mainstream material of the magnetic core used in current transformers today is manganese-zinc ferrite, which is relatively expensive and will increase the manufacturing cost of the transformer;

[0006] (4) The mechanical strength of the current transformer terminals may be insufficient. If fatigue cracks appear on the terminals, they will gradually expand until they break, making it unable to work normally.

[0007] The disclosure of the above background technology content is only used to assist in understanding the concept and technical solution of the present invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above content has been disclosed on the filing date of this patent application, the above background technology should not be used to evaluate the novelty and creativity of the present application. Summary of the invention

[0008] In order to solve the above technical problems, the present invention proposes a current transformer, which can not only reduce the core loss but also enhance the EMC (Electro Magnetic Compatibility) effect of the product.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] The present invention discloses a current transformer, comprising a skeleton, a winding, a first magnetic core, a second magnetic core, a first terminal and a second terminal, wherein the skeleton comprises a first side portion, a second side portion and a connecting portion, wherein the connecting portion is a hollow cylindrical structure, and the first side portion and the second side portion are respectively integrally connected to the two ends of the connecting portion; the winding is wound on the outer wall of the connecting portion, and the first terminal and the second terminal are respectively connected to the first side portion and the second side portion and are respectively electrically connected to the winding; the first magnetic core and the second magnetic core respectively adopt a U-shaped blade structure, and the openings of the U-shaped blade structures of the first magnetic core and the second magnetic core are relatively connected to the skeleton, wherein the first ends of the U-shaped blade structures of the first magnetic core and the second magnetic core are mutually connected to the inner cavity of the connecting portion, and the second ends of the U-shaped blade structures of the first magnetic core and the second magnetic core are mutually connected above the winding.

[0011] Further, the first terminal and the second terminal are integrally connected to the first side portion and the second side portion respectively.

[0012] Furthermore, the frame is made by injection molding, and the first terminal and the second terminal are placed in an injection mold before injection molding the frame to be integrally connected to the first side portion and the second side portion respectively.

[0013] Further, the first terminal includes a first primary coil and a first secondary terminal, the first secondary terminal is arranged between two ends of the first primary coil, and the first secondary terminal is electrically connected to the winding; and / or,

[0014] The second terminal includes a second primary coil and a second secondary terminal, wherein the second secondary terminal is disposed between two ends of the second primary coil and is electrically connected to the winding.

[0015] Further, the first secondary terminal includes 1 to 5 first sub-secondary terminals, and each of the first sub-secondary terminals is arranged in parallel between two ends of the first primary coil; and / or,

[0016] The second secondary terminal includes 1 to 5 second sub-secondary terminals, and each of the second sub-secondary terminals is arranged in parallel between two ends of the second primary coil.

[0017] Further, the width of the end of the first primary coil is greater than the width of the end of each of the first sub-secondary terminals; and / or,

[0018] A width of an end portion of the second primary coil is greater than a width of an end portion of each of the second sub-secondary terminals.

[0019] Further, the width of the end of the first primary coil is 1.2 to 3 times the width of the end of each of the first sub-secondary terminals; and / or,

[0020] A width of an end portion of the second primary coil is 1.2 to 3 times a width of an end portion of each of the second sub-secondary terminals.

[0021] Further, each of the first sub-secondary terminals adopts a C-type PIN needle, an L-type PIN needle or a seagull-shaped PIN needle; and / or each of the second sub-secondary terminals adopts a C-type PIN needle, an L-type PIN needle or a seagull-shaped PIN needle.

[0022] Furthermore, the thickness of the top blades located above the windings on the U-shaped blade structures of the first magnetic core and the second magnetic core is greater than or equal to 0.5 mm.

[0023] Furthermore, the top blades on the U-shaped blade structures of the first magnetic core and the second magnetic core, which are located above the winding, are semicircular, semi-elliptical or polygonal in shape, respectively.

[0024] Furthermore, the bottom surfaces of the top blades on the U-shaped blade structures of the first magnetic core and the second magnetic core, which are located above the windings, respectively abut against the top surfaces of the first side portion and the second side portion; the inner side walls of the openings of the U-shaped blade structures of the first magnetic core and the second magnetic core, respectively abut against the side surfaces of the first side portion and the second side portion.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: the current transformer disclosed in the present invention has a skeleton comprising a connecting portion of a hollow cylindrical structure and a first side portion and a second side portion connected at both ends of the connecting portion; the first magnetic core and the second magnetic core respectively adopt a U-shaped blade structure and are relatively connected to the skeleton; on the one hand, the bottom blades of the U-shaped blade structure of the first magnetic core and the second magnetic core are connected in the inner cavity of the hollow cylindrical structure of the connecting portion to form a core center column; compared with the existing EE-type magnetic core, EF-type magnetic core or EP-type magnetic core, the first magnetic core and the second magnetic core of this structure no longer require magnetic columns on both sides of the magnetic core, and the overall volume is significantly reduced, thereby reducing the core loss. At the same time, due to the reduction in overall size, the cost of the core material is also reduced; on the other hand, the top blades of the U-shaped blade structure of the first magnetic core and the second magnetic core are located above the winding, which is equivalent to blocking the top of the winding, and can absorb part of the interference emitted outward by the winding, thereby increasing the EMC effect of the product.

[0026] In a further solution, the current transformer in the present invention combines the primary coil and the secondary terminal on the same side, that is, the primary side and the secondary side are combined on the same side, which increases the stability of the product while increasing the upper limit of the rated current, and can meet more user usage environments with the same size. Furthermore, the width of the two ends of the primary coil is 1.2 to 3 times the width of the end of the secondary terminal, and the two ends of the primary coil are located outside the secondary coil, so that the overall stability of the product is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic structural diagram of a current transformer according to a preferred embodiment of the present invention;

[0028] Figure 2 yes Figure 1 Schematic diagram of the explosion structure of the current transformer;

[0029] Figure 3 It is a structural schematic diagram in which the first terminal and the second terminal are integrally connected to the frame.

[0030] Description of Figure Numbers:

[0031] 10. Skeleton; 11. First side; 12. Second side; 13. Connecting portion; 20. Winding; 31. First magnetic core; 32. Second magnetic core; 41. First terminal; 411. First primary coil; 412. First secondary terminal; 4121. First sub-secondary terminal; 42. Second terminal; 421. Second primary coil; 422. Second secondary terminal; 4221. Second sub-secondary terminal. DETAILED DESCRIPTION

[0032] The following is a detailed description of the embodiments of the present invention. It should be emphasized that the following description is only exemplary and is not intended to limit the scope and application of the present invention.

[0033] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it can be directly on the other component or indirectly on the other component. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, connection can be used for both fixing and circuit / signal communication.

[0034] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0035] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0036] like Figure 1 As shown, a preferred embodiment of the present invention discloses a current transformer, including a skeleton 10, a winding 20, a first magnetic core 31, a second magnetic core 32, a first terminal 41 and a second terminal 42, the skeleton 10 includes a first side portion 11, a second side portion 12 and a connecting portion 13, the connecting portion 13 is a hollow cylindrical structure, the first side portion 11 and the second side portion 12 are respectively connected to the two ends of the connecting portion 13 as a whole; the winding 20 is wound on the outer wall of the connecting portion 13, the first terminal 41 and the second terminal 42 are respectively connected to the first side portion 11 and the second side portion 12 and are respectively electrically connected to the winding 20; the first magnetic core 31 and the second magnetic core 32 respectively adopt a U-shaped blade structure, and the openings of the U-shaped blade structures of the first magnetic core 31 and the second magnetic core 32 are relatively connected to the skeleton 10, wherein the first ends of the U-shaped blade structures of the first magnetic core 31 and the second magnetic core 32 are mutually connected to the inner cavity of the connecting portion 13, and the second ends of the U-shaped blade structures of the first magnetic core 31 and the second magnetic core 32 are mutually connected to the top of the winding 20.

[0037] The first terminal 41 and the second terminal 42 are respectively connected to the first side portion 11 and the second side portion 12. Furthermore, the frame 10 is made by injection molding, and the first terminal 41 and the second terminal 42 are placed in an injection mold before the frame 10 is injection molded to be respectively connected to the first side portion 11 and the second side portion 12.

[0038] The first terminal 41 includes a first primary coil 411 and a first secondary terminal 412, the first secondary terminal 412 is arranged between the two ends of the first primary coil 411, and the first secondary terminal 412 is electrically connected to the winding 20, and the first primary coil 411 does not need to be electrically connected to the winding 20; wherein, the first secondary terminal 412 includes 1 to 5 first sub-secondary terminals 4121, and each first sub-secondary terminal 4121 is arranged parallel to each other between the two ends of the first primary coil 411; in this embodiment, the first secondary terminal 412 includes 3 first sub-secondary terminals 4121, and each first sub-secondary terminal 4121 adopts a C-type PIN needle, an L-type PIN needle or a seagull-type PIN needle. The width of the end of the first primary coil 412 is greater than the width of the end of each first sub-secondary terminal 4121. Specifically, the width of the end of the first primary coil 412 is 1.2 to 3 times the width of the end of each first sub-secondary terminal 4121; for example, the width of the end of each first sub-secondary terminal 4121 is 0.6mm~0.8mm, and the width of the end of the first primary coil 412 is 1.0mm~1.5mm.

[0039] The second terminal 42 includes a second primary coil 421 and a second secondary terminal 422, the second secondary terminal 422 is arranged between the two ends of the second primary coil 421, and the second secondary terminal 422 is electrically connected to the winding 20, and the second primary coil 421 does not need to be electrically connected to the winding 20; wherein, the second secondary terminal 422 includes 1 to 5 second sub-secondary terminals 4221, and each second sub-secondary terminal 4221 is arranged parallel to each other between the two ends of the second primary coil 421; in this embodiment, the second secondary terminal 422 includes 3 second sub-secondary terminals 4221, and each second sub-secondary terminal 4221 adopts a C-type PIN needle, an L-type PIN needle or a seagull-type PIN needle. The width of the end of the second primary coil 421 is greater than the width of the end of each second sub-secondary terminal 4221. Specifically, the width of the end of the second primary coil 421 is 1.2 to 3 times the width of the end of each second sub-secondary terminal 4221; for example, the width of the end of each second sub-secondary terminal 4221 is 0.6mm~0.8mm, and the width of the end of the second primary coil 422 is 1.0mm~1.5mm.

[0040] The first primary coil 4411 and each first sub-secondary terminal 4121 , the second secondary terminal 422 and each second sub-secondary terminal 4221 are respectively placed in the mold before the frame 10 is injection molded to be integrally connected with the frame 10 .

[0041] In this embodiment, the winding 20 is formed by winding copper wire on the outer wall of the connecting portion 13, and the tail end of the copper wire is wound around each first sub-secondary terminal 4121 and each second sub-secondary terminal 4221, and the end of the copper wire is respectively welded to each first sub-secondary terminal 4121 and each second sub-secondary terminal 4221 by tin welding.

[0042] A first primary coil 411 and a second primary coil 421 with a relatively wide width are respectively arranged at both ends of the first secondary terminal 412 of the first terminal 41 and the second secondary terminal 421 of the second terminal 42 to play a supporting role, thereby increasing the overall stability of the product. Moreover, the primary and secondary coils are respectively combined on both sides of the skeleton 10, which increases the stability of the product and can also increase the upper limit of the rated current, so that more user environments can be met with the same size.

[0043] The thickness of the top blade located above the winding 20 on the U-shaped blade structure of the first magnetic core 31 and the second magnetic core 32 is greater than or equal to 0.5 mm, and the size of the top blade can be adjusted according to electrical requirements to improve product performance while increasing the product EMC effect. In addition to a rectangular structure, the top blade of the U-shaped blade structure of the first magnetic core 31 and the second magnetic core 32 can also be a semicircular, semi-elliptical or other polygonal structure, and the top can form a flat structure, which can facilitate the adsorption and assembly of the product.

[0044] The bottom surfaces of the top blades located above the winding 20 on the U-shaped blade structures of the first magnetic core 31 and the second magnetic core 32 respectively abut against the top surfaces of the first side portion 11 and the second side portion 12. The inner side walls of the openings of the U-shaped blade structures of the first magnetic core 31 and the second magnetic core 32 respectively abut against the side surfaces of the first side portion 11 and the second side portion 12.

[0045] In a specific embodiment, the first magnetic core 31 and the second magnetic core 32 can be connected to the skeleton 10 by gluing; for example, glue can be applied to the side wall of the second end of the U-shaped blade structure of the first magnetic core 31 and the second magnetic core 32 to bond the first magnetic core 31 and the second magnetic core 32; glue can also be applied to the inner side wall of the opening of the U-shaped blade structure of the first magnetic core 31 and the second magnetic core 32 to bond the first magnetic core 31 and the second magnetic core 32 to the inner wall of the connecting portion 13 respectively. Among them, the two ends of the first magnetic core 31 are respectively connected to the two ends of the second magnetic core 32, integrated into a circle of wiring, and the two sides can be connected in parallel to increase the primary side rated current, reduce the overall product size, meet the user's various application environments while improving the overall strength of the product.

[0046] The first magnetic core 31 and the second magnetic core 32 in the present invention respectively adopt a U-shaped blade structure and are relatively connected to the skeleton 10. On the one hand, the bottom blades of the U-shaped blade structure of the first magnetic core 31 and the second magnetic core 32 are connected in the inner cavity of the hollow cylindrical structure of the connecting part 13 to form a core center column. Compared with the existing EE-type magnetic core, EF-type magnetic core or EP-type magnetic core, the first magnetic core 31 and the second magnetic core 32 of this structure no longer require magnetic columns on both sides of the magnetic core, and the overall volume is significantly reduced, thereby reducing the core loss. At the same time, due to the reduction in overall size, the cost of the core material is also reduced. On the other hand, the top blades of the U-shaped blade structure of the first magnetic core 31 and the second magnetic core 32 are located above the winding 20, which is equivalent to blocking the top of the winding 20, and can absorb part of the interference emitted by the winding to the outside, thereby increasing the EMC effect of the product.

[0047] In addition, the current transformer in the present invention combines the primary coil and the secondary terminal on the same side, that is, combines the primary side and the secondary side on the same side, which increases the stability of the product while also increasing the upper limit of the rated current, and can meet more user usage environments with the same size.

[0048] The background section of the present invention may contain background information about the problem or environment of the present invention, rather than describing the prior art by others. Therefore, the content contained in the background section is not an admission by the applicant that the prior art is available.

[0049] The above content is a further detailed description of the present invention in combination with specific / preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, it can also make several substitutions or modifications to these described embodiments, and these substitutions or modifications should be regarded as belonging to the protection scope of the present invention. In the description of this specification, the description of reference terms "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, in the absence of mutual contradiction, the technical personnel in this field can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope defined by the attached claims.

Claims

1. A current transformer, characterized in that: comprising a skeleton, a winding, a first magnetic core, a second magnetic core, a first terminal and a second terminal, The skeleton comprises a first side portion, a second side portion and a connecting portion, the connecting portion is a hollow cylindrical structure, the first side portion and the second side portion are respectively connected to two ends of the connecting portion in one piece; the winding is wound on the outer wall of the connecting portion, the first terminal and the second terminal are respectively connected to the first side portion and the second side portion and are respectively electrically connected to the winding; The first magnetic core and the second magnetic core respectively adopt a U-shaped blade structure, and the openings of the U-shaped blade structures of the first magnetic core and the second magnetic core are relatively connected to the frame, wherein the first ends of the U-shaped blade structures of the first magnetic core and the second magnetic core are mutually connected in the inner cavity of the connecting part, and the second ends of the U-shaped blade structures of the first magnetic core and the second magnetic core are mutually connected above the winding.

2. The current transformer according to claim 1, characterized in that: The first terminal and the second terminal are integrally connected to the first side portion and the second side portion respectively.

3. The current transformer according to claim 2, characterized in that: The frame is made by injection molding, and the first terminal and the second terminal are placed in an injection mold before injection molding the frame to be integrally connected to the first side portion and the second side portion respectively.

4. The current transformer according to claim 1, characterized in that: The first terminal includes a first primary coil and a first secondary terminal, the first secondary terminal is disposed between two ends of the first primary coil, and the first secondary terminal is electrically connected to the winding; and / or, The second terminal includes a second primary coil and a second secondary terminal, wherein the second secondary terminal is disposed between two ends of the second primary coil and is electrically connected to the winding.

5. The current transformer according to claim 4, characterized in that: The first secondary terminal includes 1 to 5 first sub-secondary terminals, each of which is arranged in parallel between two ends of the first primary coil; and / or, The second secondary terminal includes 1 to 5 second sub-secondary terminals, and each of the second sub-secondary terminals is arranged in parallel between two ends of the second primary coil.

6. The current transformer according to claim 5, characterized in that: The width of the end of the first primary coil is greater than the width of the end of each of the first sub-secondary terminals; and / or, A width of an end portion of the second primary coil is greater than a width of an end portion of each of the second sub-secondary terminals.

7. The current transformer according to claim 6, characterized in that: The width of the end of the first primary coil is 1.2 to 3 times the width of the end of each of the first sub-secondary terminals; and / or, A width of an end portion of the second primary coil is 1.2 to 3 times a width of an end portion of each of the second sub-secondary terminals.

8. The current transformer according to claim 5, characterized in that: Each of the first sub-secondary terminals adopts a C-type PIN needle, an L-type PIN needle or a seagull-shaped PIN needle; and / or each of the second sub-secondary terminals adopts a C-type PIN needle, an L-type PIN needle or a seagull-shaped PIN needle.

9. The current transformer according to claim 1, characterized in that: The thickness of the top blades located above the windings on the U-shaped blade structures of the first magnetic core and the second magnetic core is greater than or equal to 0.5 mm.

10. The current transformer according to claim 1, characterized in that: The top blades located above the windings on the U-shaped blade structures of the first magnetic core and the second magnetic core are semicircular, semi-elliptical or polygonal in shape.

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