An integrated coil of a transformer and an inductor

Abstract

The present invention discloses an integrated transformer and inductor coil for use in an on-board LLC topology circuit. The coil comprises a transformer secondary coil and an inductor coil that are interconnected and integrally wound. The coil can be wound and connected directly on the same winding machine during production, eliminating the need for welding the transformer secondary coil and inductor coil, preventing the risk of equipment burnout due to poor welding. No additional welding processes are required, saving costs for welding connectors, solder, and labor.

Description

Technical Field

[0001] The present invention relates to the technical field of transformers and inductors for LLC topology circuits, and more particularly to an integrated coil of a transformer and an inductor. Background Art

[0002] In order to meet the conditions for using the LLC topology in a switching power supply, a high-frequency transformer and a current-doubler inductor must be used. In order to obtain a high-power, high-performance switching power supply, the transformer and inductor need to be integrated together.

[0003] The traditional manufacturing method is to connect the secondary coil of each individual transformer and the coil of the current doubler inductor together by welding so that the transformer and the current doubler inductor are integrated together. However, when the secondary coil of the transformer and the coil of the current doubler inductor are connected together by welding, poor welding often occurs, resulting in excessive resistance and thus burning of the equipment. In addition, the two coils require additional welding processes, which will increase the cost of welding connectors, solder costs and labor costs, etc. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an integrated coil of a transformer and an inductor, which can be directly wound and formed as a whole on the same winding machine during production and connected to each other. There is no need to weld the secondary coil of the transformer and the inductor coil, and there will be no problem of poor welding causing equipment to burn. There is no need to increase the welding process, saving the cost of welding connectors, solder costs and labor costs, etc.

[0005] The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0006] To solve the above technical problems, the present invention provides an integrated coil of a transformer and an inductor, which is applied to an on-board LLC topology circuit, and includes a secondary coil of a transformer and an inductor coil that are interconnected and integrally wound.

[0007] Furthermore, the secondary coil of the transformer and the inductor coil have the same wire diameter.

[0008] Furthermore, the secondary coil of the transformer and the inductor coil are made of the same material.

[0009] Furthermore, the secondary coil and the inductor coil of the transformer are both made of flat enameled insulated wire.

[0010] Furthermore, it also includes a magnetic core, which includes a top plate, a bottom plate, two side columns and at least two middle columns. The middle column and the side columns are both arranged between the top plate and the bottom plate, and the two side columns are respectively arranged on both sides of the middle column. The primary coil and the secondary coil of the transformer are wound around each middle column. The bottoms of the two side columns are each provided with a groove, and a PCB board is provided in the groove. A plurality of pins are penetrated on the PCB board by means of SMT patches, and the pins are connected to the lead wires of the primary coil of the transformer and the secondary coil. Through holes for accommodating the pins are provided on the bottom plate and the PCB board, and all the secondary coils are arranged in parallel.

[0011] Furthermore, it also includes a ceramic winding frame, which includes a coil limiting structure and a sleeve structure; the coil limiting structure is arranged on both sides of the secondary coil and is adapted to the side column, the sleeve structure is connected to the coil limiting structure and is sleeved on the outside of the middle column, a gap ring is formed between the middle column and the sleeve structure, and a protrusion structure is provided on the sleeve structure.

[0012] Furthermore, the material of the magnetic core is manganese-zinc ferrite.

[0013] Furthermore, there are three center pillars, and the cross-sectional area of each center pillar is the same.

[0014] Furthermore, the PCB board is also provided with a circular hole and a runway-shaped hole electrically connected to the through hole, the circular hole is used to accommodate the center column, the through hole is used to fix the pin, and the runway-shaped hole is used to fix the primary coil of the transformer and the lead wires of the secondary coil.

[0015] Furthermore, the top plate and the upper half of the side column are integrally formed, and the bottom plate and the lower half of the side column are integrally formed.

[0016] The present invention has the following beneficial effects:

[0017] It can be directly wound and formed as a whole on the same winding machine during production and connected to each other. There is no need to weld the secondary coil of the transformer and the inductor coil, and there will be no problem of burning the equipment due to poor welding. There is no need to increase the welding process, saving the cost of welding connectors, solder costs and labor costs, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic structural diagram of an integrated coil of a transformer and an inductor provided by the present invention.

[0019] Figure 2 This is a structural diagram of the transformer.

[0020] Figure 3 This is a structural diagram of the PCB board.

[0021] Figure 4 Schematic diagram of the structure of the magnetic core. DETAILED DESCRIPTION

[0022] The present invention will be described in detail below with reference to the examples. The examples are only preferred embodiments of the present invention and are not intended to limit the present invention.

[0023] See also Figure 1 The present invention provides a transformer and inductor integrated coil for use in an on-board LLC topology circuit. The coil comprises a transformer secondary coil 1 and an inductor coil 2, which are interconnected and integrally wound. This coil can be integrally wound and connected directly on the same winding machine during production. This eliminates the need for welding the transformer secondary coil 1 and inductor coil 2, preventing the risk of equipment burnout due to poor welding. The addition of additional welding processes eliminates the need for costly welding connectors, solder, and labor.

[0024] Furthermore, the secondary coil 1 of the transformer and the inductor coil 2 have the same wire diameter, and the secondary coil 1 of the transformer and the inductor coil 2 are made of the same material, so that materials with the same wire diameter can be used, reducing manufacturing difficulty.

[0025] Furthermore, the materials of the secondary coil 1 and the inductor coil 2 of the transformer are both flat enameled insulated wires.

[0026] See also Figures 2 to 4, further, it also includes a magnetic core 3, the magnetic core 3 includes a top plate 31, a bottom plate 32, two side columns 33 and at least two middle columns 34, the middle column 34 and the side columns 33 are both arranged between the top plate 31 and the bottom plate 32, the two side columns 33 are respectively arranged on both sides of the middle column 34, each middle column 34 is wound with the primary coil of the transformer and the secondary coil 1, the bottom of the two side columns 33 are provided with a groove, a PCB board 4 is provided in the groove, a plurality of pins 5 are penetrated on the PCB board 4 by means of SMT patches, the pins 5 are connected to the lead wires of the primary coil 1 of the transformer and the secondary coil, the bottom plate 32 and the PCB board 4 are provided with through holes 6 for accommodating the pins 5, and all the secondary coils 1 are arranged in parallel. Since each middle column 34 is wound with a primary coil and a secondary coil 1, each primary coil, secondary coil 1 and magnetic core 3 form an independent transformer. Each independent transformer shares a common magnetic circuit, and multiple primary coils and secondary coils 1 are integrated on a magnetic core 3 using the common magnetic circuit. Since all secondary coils 1 are arranged in parallel, the power is multiplied. Multiple coils make the volume smaller, easier to dissipate heat, high power density, strong magnetic coupling ability, small electromagnetic interference, easy to manufacture, and highly versatile. A PCB board 4 is set at the bottom of the side column 33, and pins 5 are set to lead out the lead wires through SMT patch method, and the plug-in installation method is changed to SMT installation method, which is convenient for automatic patch, simple to assemble, easy to form automated production, and reduces costs.

[0027] Furthermore, the material of the magnetic core 3 is manganese-zinc ferrite.

[0028] Furthermore, there are three center pillars 34, and the cross-sectional areas of the center pillars 34 are the same. The cross-sectional areas of the center pillars 34 are the same, which means that the difference between the cross-sectional areas is within 5%, especially within 3%.

[0029] Furthermore, the PCB board 4 is also provided with a circular hole 7 and a runway-shaped hole 8 electrically connected to the through hole 6. The circular hole 7 is used to accommodate the center column 34, the through hole 6 is used to fix the pin 5, and the runway-shaped hole 8 is used to fix the primary coil 1 of the transformer and the lead wire of the secondary coil. Each through hole 6 and runway-shaped hole 8 is provided with a solder pad, and the through hole 6 and the runway-shaped hole 8 are electrically connected. In this way, the pin 5 can be conveniently assembled in the form of an SMT patch, automation is achieved, and production costs are reduced.

[0030] Furthermore, the top plate 31 and the upper half of the side column 33 are integrally formed, and the bottom plate 32 and the lower half of the side column 33 are integrally formed to facilitate assembly.

[0031] Furthermore, an air gap is formed in the middle of the center column 34 .

[0032] Furthermore, the pin 5 is in a T-shape, which occupies less space and is more conducive to product miniaturization. The ends of the multiple pins 5 remain flush, so that the transformer and other components can be assembled using SMT patches, further realizing automated production and reducing production costs.

[0033] Furthermore, the top plate 31 and bottom plate 32 are formed by a plurality of unit magnetic blocks laid flat and spliced together, while the center column 34 and side columns 33 are formed by a plurality of stacked unit magnetic blocks. The unit magnetic blocks are flat, bar-shaped blocks with arc-shaped ends. This method ensures a uniform distribution of air gaps between each individual magnetic core 3, delaying magnetic saturation and enabling the transformer to maintain high efficiency at high frequencies. The flat, bar-shaped unit magnetic blocks facilitate production of the magnetic core 3, facilitating miniaturization and planarization, and the stacked production method is more conducive to automated production. Furthermore, a preset gap exists between the ends of two adjacent, flatly spliced unit magnetic blocks, increasing the magnetic resistance between the unit magnetic blocks and drawing the edge magnetic lines of force closer to the center of the magnetic core 3, thereby reducing diffuse magnetic flux.

[0034] Furthermore, the side pillars 33 are formed by stacking half of the unit magnetic blocks, the length of the half unit magnetic block remains unchanged, the width is halved, and the cross section of the half unit magnetic block faces the middle pillar 34 .

[0035] Furthermore, each of the unit magnetic blocks is fixed by glue.

[0036] Furthermore, the device also includes a ceramic winding frame, comprising a coil retaining structure and a sleeve structure. The coil retaining structures are located on either side of the secondary coil 1 and mate with the side legs 33. The sleeve structure connects to the coil retaining structures and fits over the center leg 34, forming a gap between the center leg 34 and the sleeve structure. The sleeve structure is also provided with a raised structure. Compared to winding frames made of plastic, ceramic materials have a higher thermal conductivity (2.5 W / m•K to 320 W / m•K), which is several times, dozens of times, or even nearly a hundred times greater than that of plastic.

[0037] The above embodiments merely express the implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. Any technical solution obtained in the form of equivalent replacement or equivalent transformation should fall within the scope of protection of the present invention.

Claims

1. A transformer and inductor integrated coil, which is applied to an on-board LLC topology circuit, characterized in that: The invention relates to a transformer comprising a secondary coil and an inductor coil which are interconnected and integrally wound. The wire diameters of the secondary coil and the inductor coil of the transformer are the same. The materials of the secondary coil and the inductor coil of the transformer are the same. The materials of the secondary coil and the inductor coil of the transformer are flat enameled insulated wires. The invention also comprises a magnetic core, which comprises a top plate, a bottom plate, two side columns and at least two middle columns. The middle column and the side columns are both arranged between the top plate and the bottom plate. The two side columns are respectively arranged on both sides of the middle column. The primary coil and the secondary coil of the transformer are wound on each middle column. The bottoms of the two side columns are provided with grooves. A PCB board is arranged in the groove. A plurality of pins are provided on the PCB board by means of SMT patches. The pins are connected to the lead wires of the primary coil and the secondary coil of the transformer. The bottom plate and The PCB board is provided with through holes for accommodating the pins, and all the secondary coils are arranged in parallel. It also includes a ceramic winding frame, and the ceramic winding frame includes a coil limiting structure and a sleeve structure; the coil limiting structures are arranged on both sides of the secondary coil, and the sleeve structure is connected to the coil limiting structure and is sleeved on the outside of the middle column. A gap ring is formed between the middle column and the sleeve structure, and a protrusion structure is provided on the sleeve structure. The material of the magnetic core is manganese-zinc ferrite, and the cross-sectional area of each middle column is the same. The PCB board is also provided with a circular hole and a runway-shaped hole electrically connected to the through hole, the circular hole is used to accommodate the middle column, the through hole is used to fix the pin, and the runway-shaped hole is used to fix the primary coil of the transformer and the lead wire of the secondary coil, the top plate and the upper half of the side column are integrally formed, and the bottom plate and the lower half of the side column are integrally formed.

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