Bus bar and bobbin structure of transformer capable of minimizing induction heating by eddy current

Abstract

The present invention relates to a busbar and bobbin structure of a transformer capable of minimizing induction heating caused by eddy currents, comprising a cylindrical bobbin (70) and a coil-shaped primary winding (10) provided on the outer circumference of the bobbin (70), wherein the secondary winding is configured as a busbar, the busbar comprises a loop-shaped first body (51a), a loop-shaped second body (52a) arranged at a certain distance from the first body (51a), and a center tap (53) connecting the first body (51a) and the second body (52a) to each other, wherein the first body (51a) and the second body (52a) are arranged in an up-and-down symmetrical form while maintaining a large surface area in a vertical state, and the center tap (53) is connected to one end of the first body (51a) and the second body (52a). It is characterized by connecting the first part vertically to each other.

Description

Technology Field

[0001] The present invention relates to a busbar and bobbin structure of a transformer used to increase or decrease voltage, and more specifically, to a transformer in which the secondary winding is configured as a busbar rather than a coil, wherein two busbar bodies are arranged in a vertical shape to minimize the area of ​​linkage with the leakage flux, thereby minimizing induction heating caused by eddy currents generated by the leakage flux, and the structure of the bobbin is improved to prevent misassembly of the busbar and to allow for easy assembly of the busbar. Background Technology

[0002] Generally, transformers are used to increase voltage and transmit it to the secondary side, or to decrease voltage and transmit it to the secondary side, depending on the number of turns of the primary and secondary coils wound on the core.

[0003] In other words, a transformer plays the role of raising or lowering the AC voltage depending on the winding ratio of the primary coil and the secondary coil.

[0004] The winding methods of the above coil include sector winding and sandwich winding.

[0005] The above sector winding method is configured to include a primary winding (10) wound in a circular shape as shown in FIG. 1a, a secondary first tap (21), a secondary second tap (22), and a center tap (30).

[0006] And the sandwich method is configured to include a primary winding (10) wound in a circular shape as shown in FIGS. 1b and 2, a secondary first tap (21), a secondary second tap (22), and a center tap (30).

[0007] Meanwhile, transformers are also used in low-voltage DC-DC converters (LDCs) for eco-friendly vehicles.

[0008] However, since the transformer used in the above low-voltage DC converter converts high-voltage power of 200 to 400 V into low-voltage power of 12 V, a large current flows through the winding with a small number of turns on the low-voltage side.

[0009] Taking this into account, a transformer has been proposed in which a conventional coil is wound on the primary winding and a bus bar is used instead on the secondary side.

[0010] A conventional transformer structure using a bus bar on the secondary side is composed of, as illustrated in FIGS. 3 and 4, a first body (41a) in the shape of a loop, a first tab (41b) provided at one end of the first body (41a), a second body (42a) in the shape of a loop provided at a certain distance from the first body (41a), a second tab (42b) bent in a right direction at the other end of the second body (42a), and a center tab (43) connecting the other end of the first body (41a) and the other end of the second body (42a).

[0011] Here, the center tab (43) extends downward from the other end of the first body (41a) and is then bent at a right angle toward the same direction as the second tab (42b).

[0012] Figure 5 illustrates a center-tap type transformer circuit, in which the transformer (T) plays the role of transferring energy while physically separating the front and rear ends.

[0013] The energy transferred at this time undergoes a rectification process and is stably delivered to the downstream end of the circuit.

[0014] While conventional transformers use a full bridge circuit with four diodes, center-tap transformers share the middle pin 4 in Fig. 5 as a ground point between the first tap and the second tap on the secondary side.

[0015] This allows the number of components required for rectification to be reduced by half.

[0016] However, the above-described conventional busbar structure has a structure in which the first body (41a) and the second body (42a) are arranged in a horizontal direction, as shown in FIG. 4.

[0017] That is, as shown in FIG. 7a, the conventional busbar has a portion with a large area arranged horizontally, so the area affected by magnetic flux lines becomes wider.

[0018] As a result, the area of ​​linkage with the leakage flux generated in the transformer winding increases, making the structure vulnerable to induction heating.

[0019] In other words, conventional busbars generate significant heat because they have a structure in which magnetic flux passes through the widest surface area of ​​the busbar.

[0020] Accordingly, conventional transformers have a problem in that high heat generated in a localized area of ​​the secondary busbar affects the entire system and degrades the performance of other components.

[0021] In addition, conventional busbar structures have the disadvantage that the busbar structure is somewhat complex, it is difficult to assemble the busbar to the correct position on the bobbin, and assembly takes a long time. Prior art literature

[0022] Korean Published Patent No. 10-2022-0072036 (Published June 2, 2022) Korean Registered Patent No. 10-1726367 (Published April 12, 2017) The problem to be solved

[0023] The present invention is proposed to solve the problems of the aforementioned prior art, and aims to reduce induction heating caused by eddy currents generated by leakage flux in a transformer in which the secondary side is composed of a bus bar.

[0024] Another objective of the present invention is to reduce the amount of heat generated by the transformer by minimizing the area of ​​linkage transmitted in the direction of magnetic flux.

[0025] Another objective of the present invention is to minimize heat generated in the secondary busbar, thereby improving the thermal stability of the system and preventing performance degradation of electrical components.

[0026] Another objective of the present invention is to improve the power conversion efficiency of a transformer by reducing eddy current losses.

[0027] Another objective of the present invention is to simplify the structure of the busbar so that it can be easily manufactured and the manufacturing cost can be reduced.

[0028] Another objective of the present invention is to improve the convenience of assembly when bolting the busbar.

[0029] Another objective of the present invention is to manufacture the bobbin as a separable type so that the busbar can be easily assembled.

[0030] Another objective of the present invention is to prevent the bus bar from being incorrectly assembled by forming an anti-mis-insertion pin on the body of the bobbin.

[0031] Another objective of the present invention is to form a separating pin on the body of the bobbin so that the upper body and the lower body of the busbar are stably fixed while maintaining a gap. means of solving the problem

[0032] To achieve the above objective, the present invention comprises a cylindrical bobbin and a coil-shaped primary winding provided on the outer circumference of the bobbin, wherein the secondary winding is configured as a bus bar, wherein the bus bar comprises a loop-shaped first body, a loop-shaped second body arranged at a certain distance from the first body, and a center tap connecting the first body and the second body to each other, wherein the first body and the second body are arranged in an up-and-down symmetrical form while maintaining a large surface area in a vertical state to minimize the influence of magnetic flux lines, and the center tap is characterized by vertically connecting one end of the first body and one end of the second body to each other.

[0033] In addition, the first body is configured to include a first body bend portion formed at one end of the first body and a first tab that is bent at a certain angle from the first body bend portion and extends outward, and is characterized in that a bolt fastening hole is formed in the first tab.

[0034] In addition, the second body is configured to include a second body bend portion formed at one end of the second body and a second tab that is bent at a certain angle from the second body bend portion and extends outward, and is characterized in that a bolt fastening hole is formed in the second tab.

[0035] In addition, the center tab is characterized by comprising a center tab bend portion formed at the other end of the first body and the second body, a joint member that is bent at a certain angle from the center tab bend portion and extends outward, and a bend member connected to one side of the joint member.

[0036] In addition, the joint member is characterized by being composed of an integral flat plate, connecting the other end of the first body and the other end of the second body to each other, and being vertically provided to face the first tab of the first body and the second tab of the second body.

[0037] In addition, the joint member is characterized by having an upper fastening hole formed on its upper portion and a lower fastening hole formed on its lower portion.

[0038] In addition, the joint member is characterized by including a bending member that is extended a certain distance from the middle portion of the joint member and then bent at a right angle.

[0039] In addition, the above-mentioned bent member is characterized by having an intermediate fastening hole formed therein.

[0040] In addition, the invention is characterized by further providing an insulating member between the outer circumference of the primary winding and the secondary busbar that is vertically provided.

[0041] In addition, the bobbin is characterized by having a cylindrical bobbin body and a lower member provided at the bottom of the bobbin body formed integrally, and a ring-shaped upper member manufactured separately and assembled from the top of the bobbin body.

[0042] In addition, the invention is characterized by having secondary winding separation pins provided on both sides of the middle portion of the bobbin body, which allow the first body and the second body of the bus bar to be separated from each other and stably fixed.

[0043] In addition, a first mis-insertion prevention pin and a second mis-insertion prevention pin are formed on the outer surface of the bobbin body to prevent mis-assembly of the bus bar, a first cut groove corresponding to the first mis-insertion prevention pin is formed on the first body of the bus bar, and a second cut groove corresponding to the second mis-insertion prevention pin is formed on the second body of the bus bar.

[0044] In addition, the first insertion prevention pin and the second insertion prevention pin are provided offset from each other with respect to the vertical direction, and the first cut groove and the second cut groove are also provided offset from each other with respect to the vertical direction.

[0045] In addition, the upper part of the bobbin body is characterized by having a locking groove and a hook that allow a ring-shaped upper member to be fitted and assembled therein.

[0046] In addition, the upper part of the bobbin body is characterized by having incisions of a certain depth intermittently formed toward the lower part. Effects of the invention

[0047] According to the present invention, by arranging the busbar in a vertical shape to minimize the influence of magnetic flux lines, the heat generated in the secondary busbar can be minimized, thereby improving the thermal stability of the system.

[0048] In addition, by improving the structure of the busbar, it is possible to reduce induction heating caused by eddy currents generated by leakage flux.

[0049] In addition, by minimizing heat generation in the busbar and improving the thermal stability of the system, it is possible to prevent the performance degradation of other components.

[0050] In addition, by reducing eddy current losses, it is possible to improve the power conversion efficiency of the transformer.

[0051] In addition, by simplifying the structure of the busbar, it can be easily manufactured and has the effect of reducing manufacturing costs.

[0052] In addition, it has the effect of improving the convenience of assembly when assembling the busbar bolts.

[0053] In addition, the insulating member provided between the primary winding and the busbar can have the effect of improving insulation performance.

[0054] In addition, manufacturing the bobbin body as a detachable type has the effect of facilitating the assembly of the busbar.

[0055] In addition, by providing a hook and a locking groove on the upper part of the bobbin body, the ring-shaped upper member can be easily assembled.

[0056] In addition, the anti-mis-assembly pin provided on the bobbin body has the effect of preventing mis-assembly during the assembly of the bus bar.

[0057] In addition, the upper busbar and the lower busbar are stably fixed while separated from each other by the secondary winding separation pin provided in the bobbin body. Brief explanation of the drawing

[0058] FIG. 1 is a drawing showing the winding method of a transformer according to the prior art. FIG. 2 is a diagram showing a sandwich winding method of the primary winding. FIG. 3 is a drawing showing an example of a transformer according to the prior art. FIG. 4 is a drawing showing a center-tap type busbar according to the prior art. Figure 5 is a diagram showing the circuit of a center-tap type busbar. FIG. 6 is a perspective view showing a busbar according to the present invention. FIG. 7 is a diagram showing magnetic flux lines acting on a busbar. FIG. 8 is a drawing showing the main parts of a transformer according to the present invention. FIG. 9 is a perspective view showing a bobbin and an upper member according to the present invention. FIG. 10 is a drawing showing the process of assembling an upper member to a bobbin body according to the present invention. Specific details for implementing the invention

[0059] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0060] In this specification, the arc-shaped portion (loop portion) of the busbar is referred to as the "body," and the flat portion bent at the end of the body is referred to as the "tap."

[0061] In the secondary side bus bar of the transformer according to the present invention, as shown in FIG. 6, the structure comprises a first body (51a) in the shape of a loop, a second body (52a) in the shape of a loop arranged at a certain distance from the first body (51a), and a center tap (53) connecting the first body (51a) and the second body (52a) to each other, wherein the first body (51a) and the second body (52a) are arranged in an up-and-down symmetrical form while maintaining a vertical state on their wide sides.

[0062] And the center tab (53) vertically connects one end of the first body (51a) and one end of the second body (52a).

[0063] Generally, as the cross-sectional area of ​​the busbar intersecting perpendicularly to the magnetic flux lines increases, the amount of heat generated by induction heating also increases.

[0064] In addition, even with the same volume, the cross-sectional area of ​​the busbar that intersects perpendicularly with the magnetic flux lines varies depending on the arrangement structure of the busbar.

[0065] Considering these points, the present invention minimizes the influence of magnetic flux lines received by the busbar by reducing the width of the busbar and increasing its height.

[0066] FIG. 7a shows the effect of magnetic flux lines received by a conventional busbar, and FIG. 7b shows the effect of magnetic flux lines received by a busbar of the present invention arranged in a vertical direction.

[0067] As can be seen in FIG. 7, the busbar according to the present invention can significantly reduce the influence of magnetic flux lines compared to conventional methods, thereby minimizing the amount of heat generated by induction heating.

[0068] In addition, the present invention arranges a wide-area bus bar through which mutually linking magnetic flux passes between the primary and secondary sides in parallel with the direction of the magnetic flux.

[0069] This allows the area where leakage flux intersects to be minimized in a bus bar of the same volume having a rectangular shape.

[0070] Additionally, the first body (51a) is configured to include a first body bend portion (51b) formed at one end of the first body (51a), and a first tab (51c) that is bent at a certain angle from the first body bend portion (51b) and extends outward.

[0071] And a bolt fastening hole (51d) is formed in the first tab (51c).

[0072] Additionally, the second body (52a) is configured to include a second body bend portion (52b) formed at one end of the second body (52a), and a second tab (52c) that is bent at a certain angle from the second body bend portion (52b) and extends outward.

[0073] And a bolt fastening hole (52d) is formed in the second tab (52c).

[0074] Additionally, the center tab (53) comprises a center tab bending portion (53b) formed at the other end of the first body (51a) and the second body (52a), a joint member (53a) that is bent at a certain angle from the center tab bending portion (53b) and extends outward, and a bending member (53e) connected to one side of the joint member (53a).

[0075] And the joint member (53a) is composed of an integral flat plate, connecting the other end of the first body (51a) and the other end of the second body (52a) to each other, and is provided vertically so as to face the first tab (51c) of the first body (51a) and the second tab (52c) of the second body (52a).

[0076] In addition, an upper fastening hole (53c) is formed on the upper part of the joint member (53a), and a lower fastening hole (53d) is formed on the lower part of the joint member (53a).

[0077] Additionally, the joint member (53a) includes a bending member (53e) that is extended a certain distance from the middle portion of the joint member (53a) and then bent at a right angle.

[0078] And an intermediate fastening hole (53f) is formed in the above-mentioned bending member (53e).

[0079] In addition, as shown in FIG. 8, the present invention further includes an insulating member (80) between the outer circumference of the primary winding (10) and the secondary bus bar that is vertically provided.

[0080] As the insulating member (80), an insulating tape or an insulating sheet may be used, and an insulating material may be applied.

[0081] By the above insulating member (80), the secondary bus bar is fixed to the bobbin while maintaining insulation.

[0082] In addition, the bobbin (70) according to the present invention is integrally formed with a cylindrical bobbin body (71) and a lower member (72) provided at the lower part of the bobbin body (71), as shown in FIG. 9.

[0083] And, a ring-shaped upper member (73) is assembled from the upper part of the bobbin body (71).

[0084] As described above, by manufacturing and assembling the bobbin (70) as a separate type, the bus bar can be easily assembled on the outer circumference of the primary winding.

[0085] In addition, on both sides of the middle portion of the bobbin body (71), as shown in FIG. 9, secondary winding separator pins (78) are provided to stably fix the upper body (51a) and lower body (52a) of the bus bar while separating them from each other.

[0086] And, on the outer surface of the bobbin body (71), a first mis-assembly prevention pin (77a) and a second mis-assembly prevention pin (77b) are formed to prevent mis-assembly of the bus bar.

[0087] In addition, a first cut groove (51e) corresponding to the first insertion prevention pin (77a) is formed in the first body (51a) of the bus bar, and a second cut groove (52c) corresponding to the second insertion prevention pin (77b) is formed in the second body (52a) of the bus bar.

[0088] In addition, the first insertion prevention pin (77a) and the second insertion prevention pin (77b) are provided offset from each other with respect to the vertical direction, and the first cut groove (51e) and the second cut groove (52c) are also provided offset from each other with respect to the vertical direction.

[0089] With the above-described structure, incorrect assembly of the busbar can be prevented at the source.

[0090] And on the upper part of the bobbin body (71), a locking groove (75) and a hook (74) are provided so that a ring-shaped upper member (73) is fitted and assembled.

[0091] In addition, an incision (76) of a certain depth is intermittently formed on the upper part of the bobbin body (71) toward the lower part.

[0092] With the above-described structure, when the upper member (73) is assembled on the upper part of the bobbin (70), the hook (74) can be folded inward, allowing for easy assembly.

[0093] The process of assembling a bus bar to a bobbin according to the present invention is described below.

[0094] First, a coil-shaped primary winding (10) is wound on the outer surface of the bobbin body (71).

[0095] Next, the first body (51a) and the second body (52a) of the busbar are assembled by interposing an insulating member (80) on the outer surface of the primary winding (10).

[0096] That is, based on the secondary winding separation pin (78), the second body (52a) of the busbar is assembled at the bottom and the first body (51a) of the busbar is assembled at the top.

[0097] At this time, the first cut groove (51e) of the busbar first body (51a) is seated on the first insertion prevention pin (77a) provided on the bobbin body (71), and the second cut groove (52e) of the second body (52a) is seated on the second insertion prevention pin (77b).

[0098] Then, the first body (51a) and the second body (52a) of the bus bar are stably fixed while maintaining a certain distance by the secondary winding separation pin (78) provided in the bobbin body (71).

[0099] Next, the upper member (73) is positioned on the upper part of the bobbin body (71), and then pressed downward.

[0100] Then, as shown in FIG. 10, the upper member (73) begins to be assembled as the hook (74) provided on the upper part of the bobbin body (71) is closed inward, and when the upper member (73) passes through the hook (74), it is caught in the catch groove (75), and the assembly of the bobbin is completed.

[0101] The foregoing describes preferred embodiments of the present invention by way of example, and the scope of the present invention is not limited to the specific embodiments described above.

[0102] A person skilled in the art to which this invention pertains will understand that various modifications and changes are possible without departing from the scope of the technical concept of this invention. Explanation of the symbols

[0103] 10: Primary winding 21: Secondary first tap 22: Secondary side 2nd tap 30: Center tap (Center Tab) 41a: First body 41b: First tap 42a: Second body 42b: Second tab 43: Center tab 51a: First body 51b: First body bend 51c: First tab 51d: Bolt fastening hole 51e: First cut groove 52a: Second body 52b: First body bent part 52c: Second tap 52d: Bolt fastening hole 52e: Second incision groove 53: Center tab 53a: Joint member 53b: Center tab bent portion 53c: Upper fastening hole 53d: Lower fastening hole 53e: Bent member 53f: Intermediate fastening hole 70: Bobbin 71: Bobbin body 72: Lower member 73: Upper member 74: Hook 75: Catching groove 76: Incision 77a: First insertion prevention pin 77b: 2nd misinsertion prevention pin 78: Secondary winding separator pin 80: Insulating member

Claims

Claim 1 A transformer comprising a cylindrical bobbin (70) and a coil-shaped primary winding (10) provided on the outer circumference of the bobbin (70), wherein the secondary winding is configured as a bus bar, the bus bar comprises a loop-shaped first body (51a), a loop-shaped second body (52a) arranged at a certain distance from the first body (51a), and a center tap (53) connecting the first body (51a) and the second body (52a) to each other, wherein the first body (51a) and the second body (52a) are arranged in an up-and-down symmetrical form while maintaining a vertical state over a wide area, and the center tap (53) vertically connects one end of the first body (51a) and one end of the second body (52a) to each other, and A busbar and bobbin structure of a transformer, characterized in that a first body (51a) comprises a first body bend portion (51b) formed at one end of the first body (51a) and a first tab (51c) that is bent at a certain angle from the first body bend portion (51b) and extends outward, and a bolt fastening hole (51d) is formed in the first tab (51c). Claim 2 delete Claim 3 A busbar and bobbin structure of a transformer, wherein the second body (52a) comprises a second body bend portion (52b) formed at one end of the second body (52a) and a second tab (52c) that is bent at a certain angle from the second body bend portion (52b) and extends outward, and a bolt fastening hole (52d) is formed in the second tab (52c). Claim 4 A busbar and bobbin structure of a transformer according to claim 1, wherein the center tab (53) comprises a center tab bend portion (53b) formed at the other end of the first body (51a) and the second body (52a), a joint member (53a) that is bent at a certain angle from the center tab bend portion (53b) and extends outward, and a bend member (53e) connected to one side of the joint member (53a). Claim 5 A busbar and bobbin structure of a transformer, characterized in that, in claim 4, the joint member (53a) is composed of an integral flat plate, connecting the other end of the first body (51a) and the other end of the second body (52a) to each other, and is vertically provided to face the first tap (51c) of the first body (51a) and the second tap (52c) of the second body (52a). Claim 6 A busbar and bobbin structure of a transformer, characterized in that, in claim 5, an upper fastening hole (53c) is formed on the upper part of the joint member (53a) and a lower fastening hole (53d) is formed on the lower part of the joint member (53a). Claim 7 A busbar and bobbin structure of a transformer, characterized in that, in claim 6, the joint member (53a) includes a bending member (53e) that is extended a certain distance from the middle portion of the joint member (53a) and then bent at a right angle. Claim 8 A busbar and bobbin structure of a transformer, characterized in that, in claim 7, an intermediate fastening hole (53f) is formed in the bending member (53e). Claim 9 A busbar and bobbin structure of a transformer according to claim 1, characterized in that an insulating member (80) is further provided between the outer circumference of the primary winding (10) and a secondary busbar provided vertically. Claim 10 A busbar and bobbin structure of a transformer according to claim 1, wherein the bobbin (70) is integrally formed with a cylindrical bobbin body (71) and a lower member (72) provided at the lower part of the bobbin body (71), and a ring-shaped upper member (73) is manufactured separately and assembled from the upper part of the bobbin body (71). Claim 11 A busbar and bobbin structure of a transformer, characterized in that, in claim 10, secondary winding separator pins (78) are provided on both sides of the middle portion of the bobbin body (71) to stably fix the busbar first body (51a) and the second body (52a) separated from each other. Claim 12 A busbar and bobbin structure of a transformer, characterized in that, in claim 11, a first mis-assembly prevention pin (77a) and a second mis-assembly prevention pin (77b) are formed on the outer surface of the bobbin body (71) to prevent mis-assembly of the busbar, a first cut groove (51e) corresponding to the first mis-assembly prevention pin (77a) is formed on the first body (51a) of the busbar, and a second cut groove (52c) corresponding to the second mis-assembly prevention pin (77b) is formed on the second body (52a) of the busbar. Claim 13 A busbar and bobbin structure of a transformer, characterized in that, in claim 12, the first insertion prevention pin (77a) and the second insertion prevention pin (77b) are provided offset from each other with respect to the vertical direction, and the first cut groove (51e) and the second cut groove (52c) are also provided offset from each other with respect to the vertical direction. Claim 14 A busbar and bobbin structure of a transformer, characterized in that, in claim 10, a locking groove (75) and a hook (74) are provided on the upper part of the bobbin body (71) to allow a ring-shaped upper member (73) to be fitted and assembled thereon. Claim 15 A busbar and bobbin structure of a transformer, characterized in that, in the upper part of the bobbin body (71), an incision (76) of a certain depth is intermittently formed toward the lower part.

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