Three-phase common mode inductor

Abstract

The utility model relates to a divisional application, the original application number is 202520621640.8, the application date is April 3, 2025, and the mold is named as an inductance magnetic core injection mold. The utility model provides a three-phase common-mode inductor, which belongs to the technical field of inductors and comprises a magnetic core and three groups of windings, the magnetic core is of an approximately triangular structure and comprises a straight part and bent parts in transition connection with two ends of the adjacent straight part, and the windings are wound on the straight part; the structure can reduce the space occupied by the magnetic core and reduce the size of equipment.

Description

[0001] This utility model is a divisional application. The original application number is 202520621640.8, the application date is April 3, 2025, and the title is "Mold for Injection Molding of Inductor Cores". Technical Field

[0002] This utility model relates to the field of inductor technology, and in particular to three-phase common-mode inductors. Background Technology

[0003] Reactors are essential equipment for compensating line charging capacity in power transmission systems. The surface of the magnetic core needs to be coated with an insulating layer or have an insulating shell, and manual operation is inefficient. In addition, the magnetic core is usually designed in the form of a circle, square or rectangular shape, which often results in magnetic components that occupy a large space. Utility Model Content

[0004] The main purpose of this utility model is to solve the technical problems mentioned above.

[0005] According to this utility model, a three-phase common-mode inductor is proposed, including a magnetic core and three sets of windings. The magnetic core has an approximately triangular structure, including a straight portion and a curved portion that transitions to connect the two ends of the adjacent straight portion. The windings are wound on the straight portion.

[0006] Preferably, the straight section is a cylindrical structure with a polygonal cross-section.

[0007] Preferably, the winding is a flat metal wire.

[0008] Preferably, the winding is a circular metal wire.

[0009] Preferably, the three-phase common-mode inductor includes a base, and has a vertical or horizontal structure.

[0010] This utility model proposes a three-phase common-mode inductor with a magnetic core that is approximately triangular in structure, including a straight portion and a curved portion that transitions between the two ends of the adjacent straight portion. The winding is wound around the straight portion. This structure can reduce the space occupied by the magnetic core and reduce the size of the device. Attached Figure Description

[0011] Referring to the accompanying drawings, the drawings used in the following description of the embodiments or prior art will be briefly introduced. Obviously, the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this utility model.

[0012] Figure 1 This is a schematic diagram of a mold for injection molding of inductor cores according to the present invention, wherein the upper mold is a perspective view and the lower mold is a three-dimensional view.

[0013] Figure 2 for Figure 1 A magnified view of A in the middle.

[0014] Figure 3 This is a perspective view of the upper mold involved in this utility model.

[0015] Figure 4 This is a perspective view of the three-phase common-mode inductor involved in this utility model.

[0016] Figure 5 This is a plan view of the magnetic core of the three-phase common-mode inductor involved in this utility model.

[0017] Figure 6 This is a physical diagram (vertical) of the three-phase common-mode inductor involved in this utility model.

[0018] Figure 7 This is a physical diagram (horizontal type) of the three-phase common-mode inductor involved in this utility model.

[0019] Explanation of icon numbers:

[0020] 10. Molds;

[0021] 11. Upper mold; 111. Injection channel; 112. Groove; 113. Semi-groove; 114. Positioning pin;

[0022] 12. Lower mold; 121. Fixing post; 122. Groove; 123. Semi-groove; 124. Positioning hole; 125. Connecting hole;

[0023] 20. Inductor core;

[0024] 30. Three-phase common-mode inductor;

[0025] 31. Magnetic core; 311. Straight section; 312. Bending section;

[0026] 32. Winding.

[0027] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. Based on the described embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0029] See Figure 1 , Figure 2and Figure 3 This application proposes a mold for injection molding of inductor cores. The mold 10 includes an upper mold 11 and a lower mold 12. The two molds (upper mold 11 and lower mold 12) cooperate with each other to form a cavity and a connecting channel that can accommodate the inductor core 20.

[0030] Symmetrical, interconnected grooves (groove 112 and groove 122) are formed on the opposing inner surfaces of the upper mold 11 and the lower mold 12. Groove 112 of the upper mold 11 is connected to the injection channel 111, which is connected to the injection molding machine or equipment or container that can provide insulating materials such as PA66l and LCP-E4008.

[0031] Insulating materials used for injection molding must pass electrical resistance testing (such as Comparative Tracking Index, CTI). In practice, PA66 (polyhexamethylene adipamide, commonly known as Nylon-66) and LCP-E4008 (liquid crystal polymer, manufactured by Sumitomo Chemical Co., Ltd., Japan) are selected, with a CTI level of III. Before injection molding, the insulating material needs to be dried at a temperature of 130-140℃ for 4-5 hours. After drying, the material is heated to make it fluid at a temperature of 300-320℃. The fluid insulating material is then ejected from the nozzle of injection channel 111 at a pressure of 100-120 MPa. Injection molding is usually performed in two stages. After the first stage of injection molding, the temperature is lowered to 80-100℃ using a cooling system. The second injection is then used to fill the fixed feet positions left by the first injection.

[0032] A groove 112 is formed in the plane of the upper mold 11. The groove 112 communicates with the injection channel 111. The injection channel 111 can be located at the end or middle of the groove, or multiple injection channels 111 can be provided. Figure 3 Taking an injection molding channel as an example, in order to ensure the smooth flow of insulating material, the groove 112 is preferably straight, and several semi-grooves 113 are opened on both sides of the groove 112 to accommodate the inductor core 20.

[0033] In some embodiments, the grooves 112 and the semi-grooves 113 can also be arranged in groups to improve the injection molding yield of inductor cores, wherein the grooves 112 can be independent or connected.

[0034] In some embodiments, a positioning post 114 is provided at the edge of the periphery of the in-plane groove 112 of the upper mold 11, which cooperates with the positioning hole 124 of the lower mold 12 to improve the stability of the upper mold 11 and the lower mold 12 when they are closed and to ensure the alignment of the molds.

[0035] On the plane of the lower mold 12, grooves 122 and semi-grooves 123 are opened corresponding to the grooves 112 and semi-grooves 113 of the upper mold 11; the groove 122 matches the groove 112, the semi-groove 123 matches the semi-groove 113, and the groove 122 and the semi-groove 123 are connected through a connecting hole 125. The connecting hole 125 can be set as a trumpet-shaped structure, with the hole connected to the groove 122 being larger and the hole connected to the semi-groove 123 being smaller. This structure ensures the smoothness of the feeding and avoids forming air bubbles in the semi-groove 123, affecting the injection molding effect.

[0036] The semi-groove 123 and the semi-groove 113 form a cavity for accommodating the inductance core 20. To improve the stability of the inductance core 20 during injection molding, fixing columns 121 are also provided in the semi-groove 123. Before injection molding, the inductance core 20 is placed in the semi-groove 123, and the fixing column 121 passes through the central hole of the inductance core 20, facilitating mechanized operation and subsequent processes such as secondary injection molding, mold insertion, and demolding. It is known that the shape of the positioning column 121 matches the central hole of the inductance core 20. For example, for a triangular core, the positioning column 121 is triangular.

[0037] On the plane of the lower mold 12, positioning holes 124 are opened corresponding to the positioning columns 114 of the upper mold 11. The positioning holes 124 cooperate with the positioning columns 114 to facilitate positioning and closing of the mold and ensure the stability and sealing of subsequent mold closing. It is known that the relative positions of the positioning column 114 and the positioning hole 124 can be interchanged.

[0038] It should be noted that the above inductance core 20 has a conventional ring structure, including ring cores with central holes such as circular, triangular, rectangular, square, and "mouth" - shaped.

[0039] The material of the inductance core 20 includes permanent magnetic materials and soft magnetic materials. Specifically, permanent magnetic materials include metal permanent magnets, ferrite permanent magnets, rare earth permanent magnets, nanostructured permanent magnets, and high-carbon steels (tungsten steel, chromium steel, cobalt steel), etc.; soft magnetic materials include metal soft magnetic materials, ferrite soft magnetic materials, amorphous soft magnetic alloys, nanocrystalline soft magnetic alloys, and amorphous-nanocrystalline alloys. For example, amorphous-nanocrystalline alloy sheets and amorphous-nanocrystalline alloy tapes.

[0040] This application also proposes an injection molding machine, including the above-mentioned mold for inductance core injection molding. The appearance dimensions and voltage resistance of the injection-molded inductance core 20 are tested, qualified products are screened, and then coil winding is carried out to obtain an inductance product.

[0041] This application also proposes a three-phase common-mode inductor, see Figure 4 and Figure 5The three-phase common-mode inductor 30 includes a magnetic core 31 and three sets of windings 32. The magnetic core 31 has an approximately triangular structure, specifically including a straight portion 311 and a curved portion 312 that transitions between the two ends of adjacent straight portions 311. The windings 32 are wound around the straight portions 311. This structure can reduce the space occupied by the magnetic core. As shown by the dotted line in Figure 5, for magnetic cores with the same outer diameter, a circular magnetic core occupies more space than a triangular magnetic core. In electronic devices such as power banks and inverters, this can significantly reduce the size of the device. In addition, the straight portion 311 can be wound with a longer winding relative to the curved segment, and the space limitation between adjacent windings can be avoided.

[0042] The straight section 311 is a cylindrical structure with a polygonal cross-section. The winding 32 includes flat metal wires and round metal wires. A base can also be provided to lead out the winding 32 and form pins on the base. Specifically, it includes a vertical structure. Figure 6 ) and horizontal structure ( Figure 7 Insulating partitions or insulating sleeves are installed between adjacent windings 32.

[0043] The surface of the magnetic core 31 is coated with an insulating coating, which can be injection molded for insulation using the injection mold 10 in the above embodiment.

Claims

1. A three-phase common-mode inductor comprising a magnetic core (31) and three sets of windings (32), characterized in that, The magnetic core (31) has an approximately triangular structure, including a straight portion (311) and a curved portion (312) that transitions between the two ends of the adjacent straight portion (311), and the winding (32) is wound around the straight portion (311).

2. The three-phase common-mode inductor of claim 1, wherein, The straight section (311) is a columnar structure with a polygonal cross-section.

3. The three-phase common-mode inductor of claim 2, wherein, The winding (32) is a flat metal wire.

4. The three-phase common-mode inductor of claim 2, wherein, The winding (32) is a circular metal wire.

5. The three-phase common-mode inductor according to claim 3 or 4, characterized in that The three-phase common-mode inductor includes a base and can be either vertical or horizontal.

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