Transformer
Through the transformer designed with frameless structure and powder core material, the problem of miniaturization and automated production of high-voltage-resistant transformers is solved, and the size and cost of the transformer are reduced, and the heat dissipation performance is improved.
Patent Information
- Application Number
- CN202011125776.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Priority Date
- 2020-08-27
- Filing Date
- 2020-10-20
- Publication Date
- 2025-07-08
- Estimated Expiration
- 2040-10-20
AI Technical Summary
During the miniaturization process, existing high-voltage-withdrawal transformers have problems such as complex production processes and requiring a large number of fixtures to fix wires, resulting in inclination of the cylinder in the center, changes in air gaps, and increasing inductance errors and costs.
Using a frameless structure, the cover plate and nickel-zinc ferrite core body are used, and the winding is directly wound on the middle column. The cover plate has air gaps and powder core material design to achieve automated production, and the pins are formed on the bottom surface of the magnetic core body, reducing production steps and costs.
The miniaturization and automated production of transformers are realized, which reduces production costs, reduces inductive errors and losses, and improves heat dissipation performance.
Smart Images
Figure CN112151238B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of magnetic components, and particularly to a transformer. Background Art
[0002] Generally, the composition of a high-voltage-resistant transformer requires a magnetic core body, an insulating skeleton, and insulating tape. With the increase in switching frequency, the miniaturization of magnetic components has become a trend in the industry. In the existing technology, there is a transformer structure directly using nickel-zinc ferrite as the skeleton. The magnetic core of the transformer structure includes an outer cylinder and an inner cylinder disposed inside the outer cylinder. This structure utilizes the insulating property of nickel-core ferrite itself with ultra-high resistivity, eliminates the winding skeleton, and realizes the miniaturization of high-voltage transformers. However, this structure has a complex technological process, which requires winding on the inner cylinder, installing the outer cylinder, dispensing and baking, and finally welding the wire to the bottom of the outer cylinder. Since the wire needs to be fixed by an external fixture during the glue solidification process, the fixture needs to enter the oven together during the glue curing process (usually several hours). Batch production not only requires a large number of fixtures, but any disturbance of the fixture is likely to cause the central inner cylinder to tilt, resulting in a change in the air gap for transformer energy storage, an increase in inductance error, a decrease in yield, and an increase in overall cost. Summary of the Invention
[0003] In view of this, the present invention provides a transformer to reduce the size and production cost of the transformer.
[0004] According to a first aspect of the present invention, a transformer is provided, including a cover plate and a magnetic core body. The magnetic core body includes a first side column and a second side column, and a middle column connecting the first side column and the second side column. A winding is wound around the middle column. The cover plate is fixed on the upper surfaces of the first side column and the second side column. Among them, an air gap of the transformer is left in the cover plate.
[0005] Preferably, the magnetic field lines passing through the cover plate are parallel to the plane where the outermost winding is located.
[0006] Preferably, the cover plate is made of a material with an internal distributed air gap.
[0007] Preferably, the cover plate is made of powder core material.
[0008] Preferably, the magnetic core body is in an I shape.
[0009] Preferably, the magnetic core body is made of nickel-zinc ferrite.
[0010] Preferably, there is no air gap between the cover plate and the upper surfaces of the first side column and the second side column of the magnetic core body.
[0011] Preferably, the first type of pins of the transformer are located on the bottom surfaces of the first side leg and the second side leg, and the upper surfaces of the first side leg and the second side leg are opposite to the bottom surfaces.
[0012] Preferably, the first type of pins are formed by electroplating on the bottom surfaces of the first side leg and the second side leg.
[0013] Preferably, the bottom surfaces of the first side leg and the second side leg have recesses formed by etching.
[0014] Preferably, the first type of pins are formed by pasting metal sheets in the recesses.
[0015] Preferably, the first type of pins includes a primary first type of pins and a secondary first type of pins. The primary first type of pins are located on the first side of the bottom surfaces of the first side leg and the second side leg, and the secondary first type of pins are located on the second side of the bottom surfaces of the first side leg and the second side leg. The first side is opposite to the second side.
[0016] Preferably, the winding is wound around the middle leg by automatic winding.
[0017] Preferably, the winding includes a primary winding and a secondary winding. The primary winding and the secondary winding are wound around the entire middle leg respectively in the direction from the first side leg to the second side leg.
[0018] Preferably, the head and tail ends of the primary winding are spot-welded to the primary first type of pins, and the head and tail ends of the secondary winding are spot-welded to the secondary first type of pins.
[0019] Preferably, the winding further includes a shielding winding wound around the middle leg.
[0020] Preferably, the shielding winding has no electrical connection.
[0021] Preferably, the shielding winding is wound outside the primary winding and the secondary winding.
[0022] Preferably, it further includes a second type of pins located on the upper surfaces of the first side leg and the second side leg. The head and tail ends of the shielding winding are spot-welded to the second type of pins.
[0023] Preferably, the distance between the primary first type of pins and the secondary first type of pins is set to meet the standard electrical clearance and creepage distance.
[0024] The transformer structure provided by the present invention directly electroplates the first type of pins on the bottom surface of the magnetic core body. It is a transformer structure without a skeleton, which reduces the size of the transformer. In addition, by setting the cover plate as a powder core material and setting the positions of the first type of pins on the primary side and the first type of pins on the secondary side, the transformer of the present invention can achieve fully automatic production, reducing the production cost. Description of the Drawings
[0025] Figure 1 It is a structural diagram of a transformer according to an embodiment of the present invention;
[0026] Figure 2 It is a schematic diagram of the internal magnetic field of a transformer according to an embodiment of the present invention;
[0027] Figure 3 It is a structural diagram of the bottom pins of a transformer according to an embodiment of the present invention;
[0028] Figure 4 It is a structural diagram of a transformer according to another embodiment of the present invention. Detailed Embodiment
[0029] The present invention will be described in more detail below with reference to the drawings. In each drawing, the same components are denoted by similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale. In addition, some well-known parts may not be shown. For the sake of brevity, the structure obtained after several steps may be described in one drawing. Many specific details of the present invention are described below, such as the structure, material, size, processing technology and techniques of each component, in order to understand the present invention more clearly. However, as those skilled in the art can understand, the present invention can be implemented without these specific details.
[0030] The present invention provides a transformer, including a cover plate and a magnetic core body. The magnetic core body includes a first side leg and a second side leg, and a middle leg connected to the first side leg and the second side leg. A winding is wound around the middle leg; the cover plate is fixed on the upper surfaces of the first side leg and the second side leg, wherein an air gap of the transformer is left in the cover plate.
[0031] Specifically, as Figure 1As shown, the transformer 100 includes a cover plate 101 and a magnetic core body 102. The magnetic core body includes a first side leg 110 and a second side leg 112, and a middle leg 111 connecting the first side leg 110 and the second side leg 112. A winding (not shown in the figure) is wound around the middle leg. The cover plate 101 is fixed on the upper surfaces of the first side leg 110 and the second side leg 112. Among them, an air gap of the transformer is left in the cover plate 101. There is no designed air gap between the cover plate 101 and the upper surfaces of the first side leg 110 and the second side leg 112 of the magnetic core body 102. In this embodiment, the magnetic core body 102 is of an I-shaped magnetic core body structure. Preferably, the first side leg 110 and the second side leg 112 can be set as straight quadrangular prisms, and the middle leg 111 can be set as a polygonal prism or a cylinder, which is not limited herein. The magnetic core body 102 is made of nickel-zinc ferrite.
[0032] The winding includes a primary winding and a secondary winding. First, the primary winding is wound around the entire middle leg in the direction from the first side leg 110 to the second side leg 112, and then the secondary winding is wound around the entire middle leg in the direction from the first side leg 110 to the second side leg 112. The secondary winding covers the primary winding. The primary winding and the secondary winding are both electrically connected.
[0033] The cover plate 101 can be set as a material with an internal distributed air gap. Preferably, the cover plate 101 is made of powder core material. The powder core material is generally a powder core material with a low magnetic permeability (90u - 9u), such as alloy powder, metal powder, iron powder, etc.
[0034] As Figure 2 shown, it is a schematic diagram of the internal magnetic field of the transformer according to the embodiment of the present invention. Because an air gap of the transformer is left in the cover plate 101, the magnetic voltage drop is evenly dropped in the cover plate, and the magnetic force lines 125 passing through the cover plate 101 are parallel to the plane where the outermost winding 103 is located. Therefore, the component of the magnetic force lines perpendicular to the winding plane is very small, mainly the horizontal component. Therefore, the eddy current loss generated in the winding is less, reducing the AC resistance of the winding and further reducing the loss of the transformer. In addition, because the air gap is left in the cover plate 101, there is no need to specially pad an air gap between the cover plate 101 and the magnetic core body 102, eliminating the step of padding the air gap with tape or insulating material, and automatic assembly production can be realized, greatly reducing the cost of small-sized transformers. Further, due to the tight bonding between the cover plate and the magnetic core body, the heat loss generated on the cover plate 101 is more easily dissipated to the lower surface of the magnetic core body 102 and transferred to the PCB, improving the heat dissipation characteristics of the transformer.
[0035] As Figure 3As shown in the figure, it is a schematic diagram of the first type of pins at the bottom of a transformer according to an embodiment of the present invention. The first type of pins of the transformer are located on the bottom surfaces of the first side leg 110 and the second side leg 112, and the upper surfaces of the first side leg 110 and the second side leg 112 are opposite to the bottom surfaces. The first type of pins includes a primary first type of pins 121 and 122 and a secondary first type of pins 123 and 124. The primary first type of pins 121 and 122 are located on the first side of the bottom surfaces of the first side leg 110 and the second side leg 112, and the secondary first type of pins 123 and 124 are located on the second side of the bottom surfaces of the first side leg 110 and the second side leg 112. The first side is opposite to the second side. The winding can be wound around the middle leg 111 by an automatic winding method. Specifically, the winding includes a primary winding and a secondary winding. First, the primary winding is wound around the entire middle leg in the direction from the first side leg 110 to the second side leg 112, and then the secondary winding is wound around the entire middle leg in the direction from the first side leg 110 to the second side leg 112. The secondary winding covers the primary winding. Among them, an insulating material, such as an insulating tape, is also wound between the primary winding and the secondary winding. The leading end and the trailing end of the winding of the primary winding are respectively spot-welded to the primary first type of pins 121 and 122, and the leading end and the trailing end of the winding of the secondary winding are respectively spot-welded to the primary first type of pins 123 and 124.
[0036] In this embodiment, the bottom surfaces of the first side leg 110 and the second side leg 112 have recesses formed by etching, and the first type of pins is formed by pasting metal sheets in the recesses. Of course, those skilled in the art can also directly electroplate metal on the bottom surfaces of the first side leg 110 and the second side leg 112 to form the first type of pins of the transformer, which is not limited herein. The metal sheets and the electroplated metal can both select silver materials.
[0037] In addition, the distance between the primary first type of pins and the secondary first type of pins is set to meet the standard electrical clearance and creepage distance. Setting an appropriate distance C can achieve a transformer with high withstand voltage.
[0038] The transformer structure provided by the present invention directly electroplates the first type of pins on the bottom surface of the magnetic core body, which is a transformer structure without a skeleton, reducing the size of the transformer. In addition, by setting the cover plate as a powder core material and setting the positions of the primary and secondary first type of pins, the transformer of the present invention can achieve fully automatic production, reducing the production cost.
[0039] Such as Figure 4As shown, it is a structural diagram of a transformer according to another embodiment of the present invention. The difference between the transformer of this embodiment and the first embodiment is that the winding further includes a shielding winding 433 wound around the middle column 411. Among them, the shielding winding 433 is wound outside the primary winding (431 or 432) and the secondary winding (431 or 432), and the shielding winding 433 is not electrically connected. An insulating material, such as insulating tape, etc., is also wound between the primary winding or secondary winding (431 or 432) and the shielding winding 433. Further, the transformer also includes a second type of pin 421 located on the upper surfaces of the first side column 410 and the second side column 412. The head and tail ends of the shielding winding 433 are soldered to the second type of pin 421.
[0040] In this embodiment, by winding a shielding winding outside the primary winding and the secondary winding, it is possible to prevent the magnetic field lines generated by the primary winding and the secondary winding from dissipating heat to the outside and generating near-field interference to the surrounding electronic components or circuit boards.
[0041] As described above according to the embodiments of the present invention, these embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, according to the above description, many modifications and variations can be made. These embodiments are selected and specifically described in this specification in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and its modifications based on the present invention. The present invention is only limited by the claims and their full scope and equivalents.
Claims
1. A transformer, comprising a cover plate and a magnetic core body, wherein the magnetic core body includes a first side leg and a second side leg, and a middle leg connected to the first side leg and the second side leg, and a winding is wound around the middle leg; the cover plate is fixed on the upper surfaces of the first side leg and the second side leg; Among them, there is no air gap between the cover plate and the upper surfaces of the first side leg and the second side leg of the magnetic core body, the cover plate is made of a material with an internal distributed air gap, an air gap of the transformer is left in the cover plate, and the magnetic flux lines passing through the cover plate are parallel to the plane where the outermost winding is located.
2. The transformer according to claim 1, wherein, The cover plate is made of powder core material.
3. The transformer according to claim 1, wherein, The magnetic core body is in an I shape.
4. The transformer according to claim 1, wherein, The magnetic core body is made of nickel-zinc ferrite.
5. The transformer according to claim 1, wherein, The first type of pins of the transformer are located on the bottom surfaces of the first side leg and the second side leg, and the upper surfaces of the first side leg and the second side leg are opposite to the bottom surfaces.
6. The transformer according to claim 5, wherein, The first type of pins are formed by electroplating on the bottom surfaces of the first side leg and the second side leg.
7. The transformer according to claim 5, wherein, The bottom surfaces of the first side leg and the second side leg have recesses formed by etching.
8. The transformer according to claim 7, wherein, The first type of pins are formed by pasting metal sheets in the recesses.
9. The transformer according to claim 5, wherein, The first type of pins include a primary first type of pins and a secondary first type of pins. The primary first type of pins are located on the first side of the bottom surfaces of the first side leg and the second side leg, and the secondary first type of pins are located on the second side of the bottom surfaces of the first side leg and the second side leg, and the first side is opposite to the second side.
10. The transformer according to claim 1, wherein, The winding is wound around the middle leg by automatic winding.
11. The transformer according to claim 1, wherein, The winding includes a primary winding and a secondary winding, and the primary winding and the secondary winding are wound around the entire middle leg respectively in the direction from the first side leg to the second side leg.
12. The transformer according to claim 11, wherein, The head and tail ends of the primary winding are spot-welded to the primary first type of pins, and the head and tail ends of the secondary winding are spot-welded to the secondary first type of pins.
13. The transformer according to claim 11, wherein, The winding further includes a shielding winding wound around the middle leg.
14. The transformer according to claim 13, wherein, The shielding winding is wound outside the primary winding and the secondary winding.
15. The transformer according to claim 13, wherein, It further includes a second type of pins located on the upper surfaces of the first side leg and the second side leg, and the head and tail ends of the shielding winding are spot-welded to the second type of pins.
16. The transformer according to claim 9, wherein, The distance between the primary first type of pins and the secondary first type of pins is set to meet the standard electrical clearance and creepage distance.
Citation Information
Patent Citations
Pulse transformer with short-circuit-proof structure
CN204464010U
Transformer
CN213958701U
Magnetic component
US20180336986A1