JP6317948B2 - Transformer coil connection structure and transformer - Google Patents

Description

  The present invention relates to a coil connection structure of a transformer and a transformer including the same.

  A conventional transformer including a primary side coil and a secondary side coil includes, for example, two spiral plate portions in which a primary side coil is wound in a spiral shape and arranged in an axial direction as described in Patent Document 1, There is one configured by connecting the inner ends (coil ends) of the two spiral plate portions with lead wires.

JP 2004-303823 A

As a method of connecting the inner ends of these two spiral plate portions, for example, in a state where the two inner ends are in contact with each other, an electric current is passed between these two inner ends, It is conceivable to weld the inner ends of the two spiral plate portions with heat generated by electrical resistance in the portion.
However, if the above-described welding is performed in a state where the welding surfaces of the two inner end portions are in surface contact, the electrical resistance at the contact portion is small, and there is a risk of poor welding. When a welding failure occurs, the electrical resistance at the connection portion of the two spiral plate portions of the primary side coil becomes much larger than the other portions, resulting in variations in the characteristics of the primary side coil. As a result, the transformer performance may be degraded.

  In addition, conventionally, in order to prevent the above-described welding failure from occurring, a point-like welding projection that protrudes toward the other welding surface is formed on one welding surface of the welding surfaces of the two inner end portions. A method of performing the above-described welding (spot welding) with the welding projection in contact with the other welding surface is also conceivable. However, in this method, since the connecting portion between the two inner end portions is small, the electric resistance at the connecting portion of the two spiral plate portions is still larger than the other portions, and the characteristics of the primary coil are varied. There is a problem that.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a coil connection structure of a transformer capable of suppressing deterioration in performance of the transformer, and a transformer including the same.

In order to solve this problem, the coil connection structure of the transformer of the present invention has two spiral plate portions wound in a spiral shape arranged in the axial direction and is located on the inner edge side located radially inward of the two spiral plate portions. Are connected to each other by welding to form a coil connection structure of a transformer constituting at least one of a primary side coil and a secondary side coil, and the end portions on the inner edge side of the two spiral plate portions are mutually connected. A welding projection protruding toward the other welding surface is formed on one welding surface of the two welding surfaces, and the welding projection is formed on the welding surface. The end portions on the inner edge side of the two spiral plate portions are bent in the axial direction with respect to the main body portion extending in the circumferential direction of the spiral plate portion, thereby The welding surface of the spiral plate portion is Facing the circumferential direction of the serial spiral plate portion, the end portion of the inner edge of two of said spiral plate unit is characterized by being bent in opposite directions.

According to the present invention, compared to the case of welding in a state where the weld surfaces are simply brought into surface contact with each other, since the joining area between the end portions on the inner edge side by welding is small, the occurrence of poor welding can be suppressed. Moreover, since the joining area of the edge parts by the side of inner edge side by welding becomes large compared with the case of spot welding, the electrical resistance in the welding part of two spiral plate parts can be reduced. Therefore, it is possible to suppress variations in the characteristics of the primary side coil and the secondary side coil, and it is possible to suppress a decrease in performance of the transformer.
Moreover, since the electrical resistance in the welding part of two spiral board parts is small, compared with the past, it also becomes possible to suppress the temperature rise of the primary side coil and the secondary side coil at the time of use of a transformer.

1 is a schematic perspective view showing a transformer according to a first embodiment of the present invention. It is a schematic perspective view which shows the structure of the primary side coil with which the transformer of FIG. 1 is equipped, and a secondary side coil. In the primary coil of FIG. 2, (a) is a side view showing end portions on the inner edge side of two spiral plate portions welded to each other, and (b) is an end portion on the inner edge side of one spiral plate portion. FIG. The primary side coil which concerns on 2nd embodiment of this invention WHEREIN: (a) is a side view which shows the edge part of the inner edge side of the two spiral board parts welded mutually, (b) is one spiral board part The top view which shows the edge part of the inner edge side of this, (c) is CC sectional view taken on the line of (b). It is a top view which shows the 1st example of the edge part by the side of the inner edge of a spiral board part in the primary side coil which concerns on 3rd embodiment of this invention. It is a top view which shows the 2nd example of the edge part by the side of the inner edge of a spiral board part in the primary side coil which concerns on 3rd embodiment of this invention. In the primary side coil which concerns on 4th embodiment of this invention, it is a side view which shows the edge part of the inner edge side of the two spiral board parts welded mutually. It is a schematic sectional drawing which shows the state which mounted the trans | transformer which concerns on 5th embodiment of this invention in the mounting part. It is a perspective view which shows the spiral board part which comprises the primary side coil with which the transformer of FIG. 8 is equipped.

[First embodiment]
The first embodiment of the present invention will be described below with reference to FIGS.
As shown in FIGS. 1 and 2, the transformer 1 of this embodiment includes a primary side coil 2, a secondary side coil 3, a resin portion 4, and a transformer core 5.

The primary coil 2 is made of a conductive plate material and includes a plurality of spiral plate portions 11 wound in a spiral shape. Each spiral plate portion 11 is formed with a hole 13 through which a shaft portion 32 of the transformer core 5 described later is inserted.
The primary coil 2 of the present embodiment includes four spiral plate portions 11 (11A to 11D) arranged in the axial direction D1. The two spiral plate portions 11A and 11B located on the upper side are connected in series by connecting the end portions on the inner edge side (hereinafter referred to as inner edge end portions 15A and 15B) by welding. A series spiral unit 16A is formed. Similarly, the two spiral plate portions 11C and 11D located on the lower side are connected in series by connecting the inner edge portions 15C and 15D to each other by welding to form a second series spiral unit 16B. In each of the series spiral units 16A and 16B, an insulating sheet (not shown) is provided between the two spiral plate portions 11 and 11, and the spiral plate portions 11 and 11 except for the inner edge portions 15A to 15D are electrically connected to each other. Insulation is achieved. The two terminal plate portions 17 and 18 provided in each of the two sets of series spiral units 16A and 16B are respectively composed of end portions on the outer edge side of the spiral plate portion 11 and extend radially outward.

The two sets of series spiral units 16A and 16B are connected in parallel by connecting the two terminal plate portions 17 and 18 to each other by welding or the like. Since the two sets of series spiral units 16A and 16B are located away from each other in the axial direction D1, the terminal plate portions 17B and 18B of the second series spiral unit 16B are the terminal plate portions 17A and 18A of the first series spiral unit 16A. It is bent in the axial direction D1 so as to approach.
In the present embodiment, the two terminal plate portions 17A and 18A of the first series spiral unit 16A described above form the terminal portion 12 for electrically connecting the primary side coil 2 to the outside.

  The secondary coil 3 includes two ring plate portions 21 made of a conductive plate material and formed in an annular shape. Each ring plate portion 21 is formed slightly shorter than one round and has a C-shape in plan view. The two ring plate portions 21 are connected in series by connecting the ends in the circumferential direction D2 by welding or the like. That is, the secondary coil 3 of the present embodiment is formed in a spiral shape that is slightly shorter than the second turn. In the secondary coil 3, an insulating sheet (not shown) is provided between the two ring plate portions 21, and electrical insulation between the ring plate portions 21 is achieved.

  And the plate-shaped terminal extended in the radial direction outside at the 1st one end part of the circumferential direction D2 of the two ring board parts 21 which make the both ends of the secondary side coil 3 is drawn out to the outer side of the resin part 4 mentioned later. Plate portions 25A and 25B are formed. Further, the second end portion in the circumferential direction D2 connected to the other ring plate portion 21B of the one ring plate portion 21A also extends in the radial direction and is drawn out to the outside of the resin portion 4 described later. A terminal plate portion 25C is formed. These three terminal plate portions 25A to 25C form a terminal portion 22 for connecting the secondary coil 3 to the outside.

The secondary coil 3 configured as described above is disposed between two sets of series spiral units 16A and 16B that form the primary coil 2. For this reason, an insulating sheet (not shown) is provided between the secondary coil 3 and each series spiral unit 16A, 16B, and electrical insulation between the primary coil 2 and the secondary coil 3 is achieved. ing.
Further, the primary side coil 2 and the secondary side coil 3 are arranged so that the terminal plate portions 17A, 18A, 25A to 25C constituting the terminal portions 12 and 22 extend in the radial direction in opposite directions. The terminal plate portions 17A, 18A, 25A to 25C of the primary side coil 2 and the secondary side coil 3 are formed with through holes 19 and 29 penetrating in the thickness direction.

  The resin part 4 seals the parts of the primary side coil 2 and the secondary side coil 3 excluding the terminal plate parts 17A, 18A, 25A to 25C of the primary side coil 2 and the secondary side coil 3 forming the terminal parts 12 and 22. And fixed together. The resin portion 4 is formed so as to cover the connection portion between the terminal plate portions in the spiral plate portion 11, the ring plate portion 21, and the primary side coil 2, and has a substantially cylindrical appearance.

  The transformer core 5 is made of a magnetic material, and a pair of base portions 31 that sandwich the primary side coil 2 and the secondary side coil 3 sealed by the resin portion 4 from the axial direction D1, and the primary side coil 2 and the secondary side coil. 3 and a shaft portion 32 that is inserted through 3 and connects the two base portions 31 to each other. The transformer core 5 includes an outer portion 33 that is disposed on the outer peripheral side of the primary side coil 2 and the secondary side coil 3 and connects the two base portions 31 to each other. The transformer core 5 in the illustrated example is configured by dividing the shaft portion 32 and the outer shell portion 33 in the axial direction D1 of the primary side coil 2 and the secondary side coil 3, but is not limited thereto.

  Next, the coil connection structure of the transformer 1 according to this embodiment will be described. Here, a structure in which the inner edge portions 15A and 15B of the two spiral plate portions 11A and 11B constituting the first series spiral unit 16A are connected by welding will be described with reference to FIG. The connection structure between the inner edge portions 15C, 15D of the two spiral plate portions 11C, 11D constituting the second series spiral unit 16A is the same as that of the first series spiral unit 16A, and the description thereof is omitted.

  As shown in FIG. 3, the inner edge portions 15A and 15B of the two spiral plate portions 11A and 11B have flat welding surfaces 41 that face each other. In the present embodiment, the extending direction of the inner edge end portion 15 with respect to the main body portion 14 (see FIG. 2) extending in the circumferential direction D2 of each of the spiral plate portions 11A and 11B is in a direction orthogonal to the axial direction D1 of the spiral plate portion 11. Since it is set, the two welding surfaces 41, 41 face each other in the axial direction D1. In the present embodiment, the extending direction of the inner edge 15 extending from the main body 14 is such that the main body 14 at the end from the end of the main body 14 (the boundary between the main body 14 and the inner edge 15). It is set in a linear direction along the extending direction.

  And between the two welding surfaces 41, 41, the second welding surface (one welding surface) 41B of the second spiral plate portion 11B located on the lower side is the first of the first spiral plate portion 11A located on the upper side. A welding projection 42 that protrudes toward the welding surface (the other welding surface) 41A is formed. The welding projection 42 extends linearly along the second welding surface 41B. In the present embodiment, the extending direction of the welding projection 42 is orthogonal to the extending direction of the inner edge 15 described above. That is, the welding projection 42 is formed to extend linearly in a direction orthogonal to the extending direction of the inner edge 15. This welding projection 42 is formed by, for example, pressing the spiral plate portion 11 (conductive plate material).

  Moreover, in this embodiment, the main-body part extended in the circumferential direction D2 of the two spiral board parts 11 and 11 in the state which made the two welding surfaces 41 and 41 oppose and connected the two inner edge edge parts 15 and 15 by welding. 14 and 14 (see FIG. 2) are not in contact with each other, the inner edge 15 of one of the two spiral plate portions 11, 11 is bent with respect to the main body portion 14. In the illustrated example, the inner edge 15A (first welding surface 41A) of the first spiral plate portion 11A is disposed closer to the second spiral plate portion 11B than the main body portion 14A of the first spiral plate portion 11A. The inner edge portion 15A of the first spiral plate portion 11A is bent in a step shape with respect to the main body portion 14A.

  When connecting the two spiral plate portions 11 and 11 configured as described above, the welding projection 42 of the second spiral plate portion 11B is brought into contact with the first welding surface 41A of the first spiral plate portion 11A. In this state, an electric current is passed between the two inner edge portions 15A and 15B, and the two inner edge portions 15A and 15B may be welded with heat generated by electric resistance at the contact portion.

As described above, according to the coil connection structure of the transformer 1 of the present embodiment, the inner edge portions 15 and 15 by welding are compared with the case of welding in a state where the welding surfaces 41 and 41 are simply brought into surface contact with each other. Since the joint area between each other is small, the occurrence of poor welding can be suppressed. Moreover, since the joining area of the inner edge edge parts 15 and 15 by welding becomes large compared with the case of spot welding, the electrical resistance in the welding part of the two spiral board parts 11 and 11 can be reduced. Therefore, variation in the characteristics of the primary coil 2 can be suppressed, and the performance degradation of the transformer 1 can be suppressed.
Moreover, since the electrical resistance in the welding part of the two spiral board parts 11 and 11 is small, it also becomes possible to suppress the temperature rise of the primary side coil 2 at the time of use of the transformer 1 compared with the past.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG.
The coil connection structure according to this embodiment differs from the coil connection structure according to the first embodiment only in the shape of the welding projection formed on the inner edge 15B of the second spiral plate portion 11B. In the present embodiment, the same components as those in the coil connection structure of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

As shown in FIG. 4, the first welding surface 41 </ b> A is formed on the second welding surface 41 </ b> B of the second spiral plate portion 11 </ b> B facing the first welding surface 41 </ b> A of the first spiral plate portion 11 </ b> A, as in the first embodiment. 42 A of welding protrusions which protrude toward are formed. Similar to the first embodiment, the welding projection 42A extends linearly along the second welding surface 41B, and can be formed by, for example, pressing the spiral plate portion 11 (conductive plate material). .
However, in the present embodiment, the extending direction of the welding projection 42A is set to the extending direction of the inner edge end portion 15B extending from the main body portion 14B of the second spiral plate portion 11B. That is, the welding protrusion 42A is formed to extend linearly in the extending direction of the inner edge 15B. Moreover, the width dimension of the projection part 42A for welding along the radial direction of the second spiral plate part 11B is set to be smaller than the width dimension of the second welding surface 41B.

According to the transformer coil connection structure of the present embodiment, the same effects as those of the first embodiment can be obtained.
Further, according to the coil connection structure of the present embodiment, the welding projection 42A is compared with the case where the welding projection 42A extends in the direction orthogonal to the extending direction of the inner edge end portion 15B as in the first embodiment. The length dimension can be set longer. For this reason, in the state after welding, the electrical resistance in the welding part of the two spiral board parts 11 and 11 can further be reduced, and the performance fall of a transformer can further be suppressed.

[Third embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS.
The coil connection structure according to this embodiment differs from the coil connection structures of the first and second embodiments only in the shape of the welding projection formed on the inner edge 15 </ b> B of the second spiral plate part 11 </ b> B. ing. In the present embodiment, the same components as those in the coil connection structures of the first and second embodiments are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIGS. 5 and 6, the second welding surface 41B of the second spiral plate portion 11B facing the first welding surface 41A (see FIGS. 3 and 4) of the first spiral plate portion 11A includes the first and first Similar to the second embodiment, a welding projection 42B that protrudes toward the first welding surface 41A is formed. As in the second embodiment, the welding projection 42B extends linearly along the extending direction of the inner edge 15B. For example, the spiral plate 11 (conductive plate material) is pressed. Can be formed.

  However, in this embodiment, the welding projections 42B are configured by arranging a plurality of projections 43 protruding from the second welding surface 41B in a linear manner in the extending direction of the inner edge 15. In the illustrated example, the plurality of convex portions 43 are arranged at intervals, but, for example, adjacent convex portions 43 may be in contact with each other. In the present embodiment, for example, as shown in FIG. 5, all the convex portions 43 may be formed in a dot shape in plan view, or for example, as shown in FIG. 6, some of the convex portions 43 may have a plurality of convex portions. It may be formed so as to extend in the arrangement direction of the portions 43. For example, all the convex parts 43 may be formed so as to extend in the arrangement direction of the plurality of convex parts 43.

According to the transformer coil connection structure of this embodiment, the same effects as those of the first and second embodiments can be obtained.
Further, according to the coil connection structure of the present embodiment, when the inner edge portions 15 and 15 of the two spiral plate portions 11 and 11 are welded, each of the second spiral plate portions 11B constituting the welding projection 42B. Since the convex part 43 contacts the 1st welding surface 41A of 11 A of 1st spiral board parts separately, generation | occurrence | production of a welding defect can be suppressed more reliably. In addition, in the state after the some convex part 43 and 41 A of 1st welding surfaces were welded, it is suppressed that the electrical resistance in the welding part of the two spiral board parts 11 and 11 becomes large.

  The configuration of the third embodiment described above can also be applied to the configuration of the first embodiment. That is, in the third embodiment, the plurality of convex portions 43 are not limited to being arranged in the extending direction of the inner edge end portion 15B, and for example, in the extending direction of the inner edge end portion 15B, as in the first embodiment. They may be arranged in the orthogonal direction.

[Fourth embodiment]
Next, a fourth embodiment of the present invention will be described with reference to FIG.
Compared with the coil connection structures of the first to third embodiments, the coil connection structure according to this embodiment has only the arrangement of the inner edge ends 15 and 15 of the two spiral plate parts 11 and 11 welded to each other. Is different. In the present embodiment, the same components as those in the coil connection structures of the first to third embodiments are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 7, inner edge portions 15 and 15 of the two spiral plate portions 11 and 11 are bent in the axial direction D1 with respect to the main body portion 14 extending in the circumferential direction D2, respectively. That is, in this embodiment, the extending direction of the two inner edge end portions 15 is set to the axial direction D1. Thereby, the welding surfaces 41 and 41 of the two spiral plate parts 11 and 11 that face each other are opposed to the circumferential direction D <b> 2 of the spiral plate part 11. In the illustrated example, the two inner edge portions 15 and 15 are bent in opposite directions, but may be bent in the same direction, for example.

And the projection part 42C for welding of this embodiment is the 2nd welding surface of the 2nd spiral board part 11B which opposes the 1st welding surface 41A of the 1st spiral board part 11A similarly to 1st-3rd embodiment. It is formed so as to protrude from 41B.
The welding projection 42C in the illustrated example is formed to extend in the extending direction of the inner edge portion 15B as in the second embodiment. For example, as in the first embodiment, the second welding surface 41B is formed. May extend in a direction perpendicular to the extending direction of the inner edge end portion 15B in a plane parallel to the inner edge end portion 15B. Further, the welding projection 42C in the illustrated example is formed to extend linearly as in the first and second embodiments. For example, as in the third embodiment, a plurality of convex portions 43 (see FIG. 5). 6) may be arranged linearly.

According to the coil connection structure of the transformer of this embodiment, the same effects as those of the first to third embodiments can be obtained.
Moreover, according to the coil connection structure of this embodiment, it can weld in the state which pressed down the inner edge edge parts 15 and 15 of the two spiral board parts 11 and 11 from the circumferential direction D2.

[Fifth embodiment]
Next, a fourth embodiment of the present invention will be described with reference to FIGS.
The coil connection structure according to this embodiment is different in the configuration of the spiral plate portion 11 from the coil connection structures of the first to fourth embodiments. In the present embodiment, the same components as those in the coil connection structures of the first to fourth embodiments are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 9, a heat radiating terminal 51 extending in the axial direction D1 and extending to the outside is formed on the inner edge 15 of the one spiral plate 11 constituting the coil connection structure according to the present embodiment. Yes. In the illustrated example, the heat radiating terminal 51 is formed on the second spiral plate portion 11B of the first series spiral unit 16A, but may be formed, for example, on the first spiral plate portion 11A, for example, the second It may be formed on the spiral plate portions 11C and 11D of the series spiral unit 16B.

The heat radiating terminal 51 is formed integrally with the inner edge 15 on the radially inner side of the spiral plate 11. The heat radiating terminal 51 includes a first extending plate 52 extending in the axial direction D1 from the inner edge 15 and a second extending plate extending radially outward from the tip of the first extending plate 52. Unit 53.
As shown in FIG. 8, the extension length of the first extension plate portion 52 is such that the second extension plate portion 53 protrudes outward from the end portion of the resin portion 4 in the axial direction D <b> 1. It is set so as to protrude from the end in the axial direction D1 of the transformer core 5 sandwiching the portion 4 from the axial direction D1.

In the transformer 1D of the present embodiment including the spiral plate portion 11 of the present embodiment configured as described above, the heat radiating terminal 51 protrudes radially inward from the inner peripheral surface of the resin portion 4 as shown in FIG. Arranged. The first extending plate portion 52 of the heat radiating terminal 51 extends in the axial direction D <b> 1 in the gap between the inner peripheral surface of the resin portion 4 and the shaft portion 32.
Furthermore, a cutout portion 35 for projecting the heat radiation terminal 51 to the outside is formed in one base portion 31 (the lower base portion 31 in FIG. 8) constituting the transformer core 5. The notch 35 is formed to be recessed radially inward from the radial outer edge of one base portion 31. The first extending plate portion 52 of the heat radiating terminal 51 extends to the outside of the transformer core 5 through the cutout portion 35. Accordingly, the second extending plate portion 53 of the heat radiating terminal 51 is disposed outside the transformer core 5.

The transformer 1D of the present embodiment configured as described above is mounted on a mounting unit 60 of various apparatuses, for example, as shown in FIG.
The mounting portion 60 of the present embodiment is provided on each wiring board 62, a heat sink 61 made of a material having high thermal conductivity such as aluminum, two wiring boards 62 provided on the upper surface 61 a of the heat sink 61. And a wiring board part 63 (bus bar) for electrically connecting the wiring board 62 and the terminal parts 12 and 22 of the primary side coil 2 and the secondary side coil 3. The two wiring boards 62 are arranged with a space therebetween.

In the present embodiment, the transformer 1 </ b> D is mounted in a region between the two wiring boards 62 on the upper surface 61 a of the heat sink 61. And the terminal parts 12 and 22 of the primary side coil 2 and the secondary side coil 3 are electrically connected to the wiring board part 63 by being fixed to the wiring board part 63 on each wiring board 62 by screwing.
Further, when the transformer 1 </ b> D of this embodiment is mounted on the upper surface 61 a of the heat sink 61, the second extending plate portion 53 of the heat radiating terminal 51 is connected to the heat sink 61. When the upper surface 61a of the heat sink 61 is conductive, an insulating sheet 71 may be interposed between the second extension plate portion 53 of the heat radiating terminal 51 and the upper surface 61a of the heat sink 61 as shown in the example of the drawing. . The insulating sheet 71 is preferably excellent in thermal conductivity. The heat dissipating terminal 51 may be pressed against the upper surface 61a of the heat sink 61 by screwing the terminal portions 12 and 22 of the primary coil 2 and the secondary coil 3 as described above. You may fix to the upper surface 61a of the heat sink 61 by a stop or adhesion | attachment.

According to the coil connection structure of the present embodiment, the same effects as those of the first to fourth embodiments can be obtained.
Further, according to the coil structure of the present embodiment and the transformer 1D including the coil structure, when the transformer 1D is used, the heat generated in the welded portions of the two spiral plate portions 11 and 11 constituting the primary coil 2 when energized is obtained. It is possible to efficiently escape from the heat radiation terminal 51 to the outside (heat sink 61). Thereby, the temperature rise of the primary side coil 2 can further be suppressed.

As mentioned above, although the detail of this invention was demonstrated by the said embodiment, this invention is not limited to embodiment mentioned above, A various change can be added in the range which does not deviate from the meaning of this invention.
For example, when the extending direction of the inner edge 15 extending from the main body 14 is set in a direction orthogonal to the axial direction D1 of the spiral plate 11 as in the first to third embodiments, the inner edge 15 The extending direction is not limited to being set in a linear direction along the extending direction of the main body 14. The extending direction of the inner edge end portion 15 may be set in the circumferential direction D2 of the spiral plate portion 11 following the shape of the main body portion 14, for example. That is, the inner edge end 15 may be formed in an arc shape in plan view. Further, the extending direction of the inner edge end portion 15 may be set, for example, on the radially inner side of the spiral plate portion 11.

  Furthermore, the two sets of series spiral units 16A and 16B constituting the primary coil 2 are not limited to being connected in parallel, and may be connected in series, for example. Moreover, the number of the spiral plate parts 11 constituting the primary coil 2 is not limited to that of the above embodiment, and may be at least two.

Furthermore, although the secondary side coil 3 of the said embodiment is comprised by the several ring board part 21, it is provided with a several spiral board part similarly to the primary side coil 2 of the said embodiment, for example, and two spiral boards You may comprise so that the edge parts by the side of the inner edge located in the radial inside of a part may be connected by welding. In this case, welding protrusions 42, 42A, 42B, and 42C similar to those of the above-described embodiment may be formed at the end portions on the inner edge side of the two spiral plate portions constituting the secondary coil 3. Furthermore, the inner edge side ends of the two spiral plates constituting the secondary coil 3 may be formed in the same shape as the inner edge 15 of the primary coil 2 of the above embodiment.
Thus, if the secondary side coil 3 is comprised, there exists an effect similar to the said embodiment. That is, it is possible to suppress variation in the characteristics of the secondary side coil 3, and it is possible to suppress performance degradation of the transformers 1 and 1D. Moreover, the temperature rise of the secondary side coil 3 can also be suppressed when the secondary side coil 3 is energized.

DESCRIPTION OF SYMBOLS 1,1D Transformer 2 Primary side coil 3 Secondary side coil 5 Transformer core 11,11A, 11B, 11C, 11D Spiral plate part 14,14A, 14B Main-body part 15,15A, 15B, 15C, 15D Inner edge part 31 Base part 32 Shaft part 35 Notch part 41, 41A, 41B Welding surface 42, 42A, 42B, 42C Welding projection part 43 Convex part 51 Radiation terminal 52 First extension plate part 53 Second extension plate part D1 Axial direction D2 circumference direction

Claims (5)

By arranging two spiral plate portions wound in a spiral shape in the axial direction and connecting the end portions on the inner edge side located on the radial inner side of the two spiral plate portions by welding, the primary coil and the secondary coil A coil connection structure of a transformer constituting at least one of the side coils,
The end portions on the inner edge side of the two spiral plate portions have welding surfaces facing each other,
A welding projection is formed on one of the two welding surfaces to protrude toward the other welding surface,
The welding protrusion extends linearly along the welding surface ;
The end portions on the inner edge side of the two spiral plate portions are each bent in the axial direction with respect to the main body portion extending in the circumferential direction of the spiral plate portion,
The welding surfaces of the two spiral plate portions are opposed to the circumferential direction of the spiral plate portion,
The coil connection structure for a transformer, wherein the end portions on the inner edge side of the two spiral plate portions are bent in directions opposite to each other . The extending direction of the welding projection portion formed in a linear shape is set to the extending direction of the end portion on the inner edge side extending from the main body portion extending in the circumferential direction of the spiral plate portion. The transformer coil connection structure according to claim 1 . 3. The welding projection according to claim 1 , wherein the welding protrusion is configured by arranging a plurality of protrusions protruding from the one welding surface in a line along the welding surface. 4. Transformer coil connection structure. The spiral plate portion is integrally formed against the end portion of the inner edge side in the radial direction inner side of the spiral plate, and having a heat radiating terminal that extends outside extends in the axial direction The transformer coil connection structure according to any one of claims 1 to 3 . 5. The transformer coil connection structure according to claim 4 , a pair of base portions sandwiching the primary side coil and the secondary side coil from the axial direction, and the primary side coil and the secondary side coil are inserted. A transformer core having a shaft portion connected to a pair of the base portions,
One base portion is formed with a notch that is recessed radially inward,
The transformer, wherein the heat radiating terminal extends to the outside through the notch.

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