JP2018107323A - Transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transformer capable of reducing the size while securing an insulation distance.SOLUTION: A transformer 1 includes: a bobbin in which an electric wire is wound around a winding drum portion, a first coil and a second coil on the outer periphery of the first coil are formed, and a first flange portion and a second flange portion are provided at both ends of the winding drum portion; a rod-like magnetic body arranged over the first flange portion and the second flange portion between layers of the first coil and the second coil; and a core disposed so as to surround the outer periphery of the bobbin.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a transformer.

  Conventionally, there is a transformer having a configuration in which an inner winding, an interlayer insulating tape, and an outer winding are wound around a bobbin in this order. In such a transformer, in order to ensure a creepage distance and a spatial distance between the inner winding and the outer winding, an insulating spacer is inserted at both ends of the bobbin winding frame, a barrier tape is wound, A method in which large diameter portions serving as spacers are provided at both ends of the bobbin winding frame is used.

JP, 2006-167533, A

  However, in the above transformer structure, in order to secure a creepage distance and a spatial distance between the inner winding and the outer winding, the lead wire of the inner winding in which the insulation distance between the inner winding and the outer winding is close. It is desirable to secure a distance using a spacer or the like in the vicinity. For this reason, the higher the required insulation performance, the larger the spacers and the like for securing the insulation distance, so that there is a problem that the size of the bobbin becomes larger and the transformer becomes larger.

  The disclosed technology of the present application has been made in view of the above, and an object thereof is to provide a transformer that can be miniaturized while ensuring insulation performance.

  In the disclosed technique of the present application, for example, the transformer is provided at both ends of the winding drum portion, in which an electric wire is wound around the winding drum portion to form the second coil on the outer periphery of the first coil and the first coil. A bobbin having a first collar and a second collar, and a rod-shaped magnetic body disposed between the first coil and the second coil between the first coil and the second coil; And a core arranged so as to surround the outer periphery of the bobbin.

  According to the disclosed technology, for example, the transformer can be reduced in size while improving the insulation performance.

FIG. 1 is a perspective view illustrating a transformer according to the first embodiment. FIG. 2 is a perspective view illustrating a bobbin of the transformer according to the first embodiment. FIG. 3A is a perspective view illustrating an inner winding lead hole and a lower magnetic body incorporation portion of a bobbin of the transformer according to the first embodiment. FIG. 3B is a perspective view of the inner winding lead-out hole and the lower magnetic body incorporation portion of the bobbin of the transformer according to the first embodiment when viewed from below. FIG. 4 is a perspective view showing a bobbin in a state where an inner winding and an inner line tape are wound, and a magnetic body around which the inner line tape is wound, in the transformer according to the first embodiment. FIG. 5 is a perspective view illustrating a state in which the magnetic body is incorporated in the bobbin in the transformer according to the first embodiment. FIG. 6 is a perspective view illustrating a state in which the magnetic body is fixed with an outer line tape in the transformer according to the first embodiment. FIG. 7 is a perspective view illustrating a state where the barrier tape is inserted after the magnetic body is fixed with the tape in the transformer according to the first embodiment. FIG. 8A is a longitudinal sectional view illustrating a creeping distance and a spatial distance in the transformer according to the first embodiment. FIG. 8B is a cross-sectional view illustrating the creeping distance and the spatial distance in the transformer according to the first embodiment. FIG. 9 is a longitudinal sectional view showing creepage distances and spatial distances in a transformer according to a conventional example. FIG. 10 is a perspective view illustrating a state in which a magnetic body is incorporated in the bobbin in the transformer according to the second embodiment. FIG. 11 is a perspective view illustrating a main part in a state where a magnetic body is incorporated in a bobbin in the transformer according to the second embodiment.

  Hereinafter, embodiments of the technology disclosed in the present application will be described with reference to the drawings. The following embodiment shows an example in which the disclosed technology is applied to a transformer used in a resonant power supply circuit, but is merely an example, and the disclosed technology can be widely applied to transformers in general. Moreover, each embodiment and modification shown below can be combined suitably in the range which is not contradictory.

  In the following embodiments, expressions such as “up”, “down”, “left”, “right”, “front”, and “rear” merely indicate relative positions.

[Embodiment 1]
(Transformer according to Embodiment 1)
FIG. 1 is a perspective view illustrating a transformer according to the first embodiment. The transformer 1 according to the first embodiment includes a coil unit 40, a lower core 61, an upper core 62, and an outer peripheral tape 63. The lower core 61 and the upper core 62 are, for example, E-shaped cores in which a cylindrical middle leg is erected at the center of the base part and outer legs are erected on both ends of the base part sandwiching the middle leg.

  In the transformer 1, the coil portion 40 around which the outer surface tape 24 is wound is connected to the lower front core regulating portion 14 b and the rear leg of the front leg portion 14 from the front leg portion 14 and the rear leg portion 15 side of the bobbin 10 described later. The lower core 61 is attached by inserting its E-shaped middle leg into a bobbin hole 17a described later so as to fill the space between the lower rear core restricting portion 15b of the portion 15.

  In addition, the coil portion 40 fills the space between the upper front core restricting portion 18 and the upper rear core restricting portion 19 from the upper front core restricting portion 18 and the upper rear core restricting portion 19 side of the bobbin 10 described later. The upper core 62 is attached by inserting its E-shaped middle leg into a bobbin hole 17a described later.

  And the coil part 40 has the lower core 61 and the upper core 62 fixed with an adhesive or the like with their E-shaped outer legs facing each other, and further fixed from the outer periphery with an outer peripheral tape 63. Although the outer peripheral tape 63 is a tape made of a polyester material having insulating properties, it may be an insulating material tape having an equivalent function.

(Transformer Bobbin According to Embodiment 1)
FIG. 2 is a perspective view illustrating a bobbin of the transformer according to the first embodiment. FIG. 3A is a perspective view illustrating an inner winding lead hole and a lower magnetic body incorporation portion of a bobbin of the transformer according to the first embodiment. FIG. 3B is a perspective view of the inner winding lead-out hole and the lower magnetic body incorporation portion of the bobbin of the transformer according to the first embodiment when viewed from below. 2 is a diagram illustrating the bobbin 10 of the transformer 1 according to the first embodiment, in which various tapes and windings are removed from the coil unit 40 illustrated in FIG. Further, as shown in FIG. 2, an XX axis that is a central axis of a bobbin hole 17 a to be described later is an axial direction of the bobbin 10.

  The bobbin 10 includes a winding drum part 11, a lower step part 12, an inner winding lead hole 12a, a lead hole slit 12b, a lower flange 13, a front leg part 14, a plurality of front pins 14a, a lower front core restricting part 14b, a lower magnetic part. Body positioning part 14c, rear leg part 15, plural rear pins 15a, lower rear core restricting part 15b, upper step part 16, upper flange 17, bobbin hole 17a, upper front core restricting part 18, upper magnetic body positioning A portion 18a and an upper rear core restricting portion 19;

  The lower flange 13 and the front leg 14 are an example of a first flange. The upper flange 17 is an example of a second flange portion.

  The winding drum portion 11 is a cylindrical member for winding an electric wire around the bobbin 10. An electric wire constituting the inner winding (primary coil) is wound around the portion of the winding drum portion 11 between the lower step portion 12 and the upper step portion 16. That is, the lower step portion 12 and the upper step portion 16 are for positioning the winding position of the inner winding in the winding body portion 11.

  As shown in FIGS. 3A and 3B, the inner winding lead-out hole 12a is a hole penetrating in the axial direction of the bobbin 10 from the upper surface of the lower step portion 12 to the base surface of the front pin 14a of the front leg portion 14. . The lead hole slit 12b is formed from the upper surface of the lower step portion 12 to the base of the front pin 14a of the front leg portion 14 so as to open the inner winding lead hole 12a to the lower step portion 12 and the front leg portion 14 side. It is a slit provided along the winding lead-out hole 12a. The winding start or winding end portion of the wire wound around the winding drum portion 11 between the lower step portion 12 and the upper step portion 16 is accommodated in the inner winding lead hole 12a via the lead hole slit 12b. As a result, the lead wire of the inner winding is drawn out from the inner winding lead hole 12a. Note that the inner winding lead-out hole 12a can also be called a groove by the lead-out hole slit 12b.

  The lower flange 13 is one of the flanges constituting the flanges at both ends of the bobbin 10, and a part of the arc of the lower flange 13 is connected to the front leg portion 14 and the rear leg portion 15. The front leg portion 14 includes a plurality of front pins 14 a that extend from the bottom surface in the axial direction of the bobbin 10. Moreover, the front leg part 14 has the lower front side core control part 14b which controls the movement of the lower core 61 attached to the coil part 40 (refer FIG. 1). 3A, the front leg portion 14 has a lower magnetic body positioning portion 14c serving as a recess into which a lower portion of the magnetic body 30 is fitted when a magnetic body 30 described later is attached to the bobbin 10. Have

  The rear leg portion 15 includes a plurality of rear pins 15 a that extend from the bottom surface in the axial direction of the bobbin 10. Moreover, the rear side leg part 15 has the lower back side core control part 15b which controls the movement of the lower core 61 attached to the coil part 40 (refer FIG. 1).

  The upper flange 17 is the other of the lower flange 13 constituting the flanges at both ends of the bobbin 10, and the upper front core restricting portion 18 and the upper rear core restricting portion 19 extend from a part of the arc of the upper flange 17. The upper front core restricting portion 18 restricts the movement of the upper core 62 attached to the coil portion 40 (see FIG. 1). The upper rear core restricting portion 19 restricts the movement of the upper core 62 attached to the coil portion 40.

  Further, the upper front core restricting portion 18 includes an upper magnetic body positioning portion 18a serving as a recess into which the upper portion of the magnetic body 30 is fitted when a magnetic body 30 described later is attached to the bobbin 10.

(Magnetic material attached to bobbin of transformer according to embodiment 1)
FIG. 4 is a perspective view showing a bobbin in a state where an inner winding and an inner line tape are wound, and a magnetic body around which the inner line tape is wound, in the transformer according to the first embodiment. That is, FIG. 4 shows the bobbin 10 shown in FIG. 2 after the inner winding is wound between the lower step portion 12 and the upper step portion 16 and the lead wire of the inner winding is drawn from the inner winding lead hole 12a. The state which wound the inner side line tape 20 so that the inner side winding, the lower level difference part 12, and the upper level difference part 16 may be covered is shown. The line-to-line tape is a polyester material tape having an insulating property, but may be an insulating material tape having an equivalent function.

  The magnetic body 30 has a rod shape, and when the bobbin 10 is attached to the bobbin 10, the insulating tape 31 is wound around the lower portion corresponding to the length h including the portion that fits with the lower magnetic body positioning portion 14c of the front leg portion 14. It is covered with. As an example, the magnetic body 30 is covered with an insulating tape 31 on a total of five surfaces including the upper and lower surfaces of the lower portion including the portion fitted with the lower magnetic body positioning portion 14c, two side surfaces, and one end surface. The insulating tape is a polyester material tape having an insulating property, but may be an insulating material tape having an equivalent function. Then, as shown by the one-dot chain line in FIG. 4, when the magnetic body 30 is attached to the bobbin 10, the state is as shown in FIG. FIG. 5 is a perspective view illustrating a state in which the magnetic body is incorporated in the bobbin in the transformer according to the first embodiment.

  Then, the bobbin 10 in the state shown in FIG. 5 is in the state shown in FIG. 6 when the outer interline tape 21 is wound so as to cover the portion covered with the inner interline tape 20 of the bobbin 10 together with the magnetic body 30. FIG. 6 is a perspective view illustrating a state in which the magnetic body is fixed with an outer line tape in the transformer according to the first embodiment.

  Further, as shown in FIG. 7, in the bobbin 10, a barrier tape 22 is wound around an end portion on the lower flange 13 side of a portion around which the outer line tape 21 is wound, and a barrier tape 23 is wound on an end portion on the upper flange 17 side. Is wound. The barrier tape 22 ensures an insulation distance between an outer winding (secondary coil) described later and the lower core 61. The barrier tape 23 ensures an insulation distance between an outer winding described later and the upper core 62. FIG. 7 is a perspective view illustrating a state where the barrier tape is inserted after the magnetic body is fixed with the tape in the transformer according to the first embodiment. The barrier tape 22 and the barrier tape 23 are tapes made of an insulating polyester-based or acrylic-based material, but may be adhesives or coating agents having equivalent functions.

  And although illustration is abbreviate | omitted, the electric wire which comprises an outer side coil | winding is wound around the part of the winding trunk | drum 11 between the barrier tape 22 and the barrier tape 23 with which the bobbin 10 wound the bobbin 10. That is, the magnetic body 30 is disposed across the lower flange 13 and the upper flange 17 between the inner and outer windings. Then, the outer surface tape 24 is wound around the bobbin 10 so as to cover the outer winding, the barrier tape 22, and the barrier tape 23, thereby forming the coil portion 40 (see FIG. 1). And the lower core 61 and the upper core 62 are attached to the coil part 40, and the lower core 61 and the upper core 62 are fixed with the outer periphery tape 63, and the trans | transformer 1 shown in FIG. 1 is comprised.

(Creepage distance and spatial distance in the transformer according to the first embodiment)
FIG. 8A is a longitudinal sectional view illustrating a creeping distance and a spatial distance in the transformer according to the first embodiment. FIG. 8B is a cross-sectional view illustrating the creeping distance and the spatial distance in the transformer according to the first embodiment. FIG. 9 is a longitudinal sectional view showing creepage distances and spatial distances in a transformer according to a conventional example. 8A is a view showing the vicinity of the lower magnetic body positioning portion 14c in the AA ′ cross section of FIG. 8B is a view showing the vicinity of the lower magnetic body positioning portion 14c in the BB ′ cross section of FIG.

  As shown in FIG. 8A, in the transformer 1 of the first embodiment, the creeping distance (spatial distance) between the lead wire 25a of the inner winding 25 and the outer winding 26 is α + β. Here, as shown in FIG. 8B, the creepage distance α is equal to the creepage distance α1 in the BB ′ direction in contact with the inner interline tape 20 in the vicinity of the lead hole slit 12b in the cross section of the magnetic body 30, and the magnetic body. It is the sum of the creepage distance α2 corresponding to the thickness of 30 in the AA ′ direction (that is, α = α1 + α2). The creepage distance α is an insulation distance between the inner winding 25 and the inner line tape 20 and the outer line tape 21 and the outer winding 26.

  As shown in FIG. 8A, the creepage distance β is an insulation distance between the lower surface of the barrier tape 22 and the outer winding 26 wound at a position corresponding to the portion of the magnetic body 30 not covered with the insulating tape 31. is there. The creepage distance β is an insulation distance between the outer winding 26 and the lower core 61.

  On the other hand, as shown in FIG. 9, in the conventional transformer 1Z, the creepage distance between the lead wire 25aZ drawn to the front leg portion 14Z of the inner winding 25Z wound around the winding drum portion 11Z and the outer winding 26Z. Is γ (see FIG. 9) corresponding to the height of the barrier tape 22-1Z and the barrier tape 22-2Z that are provided on the lower flange 13Z by being wound around the winding drum portion 11Z.

  Here, the creepage distance γ of the conventional example depends on the height of the barrier tape 22-2Z, but the creepage distance β of the first embodiment does not depend on the height of the barrier tape 22 and the insulating tape of the magnetic body 30. It can be seen that it depends on the length of coating 31 of h (see FIGS. 4 and 8A). That is, the transformer 1 according to the first embodiment is insulated from the outer winding 26 and the lower core 61 even when the barrier tape 22 is lower than the barrier tape 22-2Z in comparison with the conventional transformer 1Z. A distance can be secured.

  Further, the transformer 1 of the first embodiment can ensure a longer insulation distance between the lead wire 25a of the inner winding 25 and the outer winding 26 by the creepage distance α than the transformer 1Z of the conventional example. . Therefore, since the creepage distance (α + β)> the creepage distance γ can be easily established, the transformer 1 of the first embodiment secures the creepage distance and improves the insulation performance as compared with the transformer 1Z of the conventional example. It can be downsized.

  According to the first embodiment, the magnetic body 30 is inserted between the inner winding 25 and the outer winding 26 to generate leakage inductance, thereby satisfying the electrical characteristics. In the first embodiment, in the transformer 1 in which the magnetic body 30 is inserted between the inner winding 25 and the outer winding 26 as means for adjusting the leakage inductance, between the inner winding 25 and the outer winding 16 and the inner winding extraction. A creepage distance and a spatial distance between the hole 12a and the outer winding 26 can be secured, and the transformer 1 can be downsized.

  According to the first embodiment, the magnetic body 30 and the inner winding lead-out hole 12a may have a part or all of the role of ensuring the creepage distance and the spatial distance between the lead wire 25a and the outer winding 26 of the inner winding 25. it can. Therefore, it is possible to reduce the width of the barrier tape and the spacer, which has conventionally been necessary for securing the creepage distance and the spatial distance, and to reduce the size of the transformer 1. That is, since the necessary barrier tape and spacer width can be reduced, the required bobbin winding frame can be further reduced, and the transformer 1 can be made smaller than the conventional one.

(Modification of Embodiment 1)
In the first embodiment described above, in the transformer 1, the bobbin 10 has the inner winding 25 wound between the lower step portion 12 and the upper step portion 16, and the lead wire 25 a of the inner winding 25 is routed from the inner winding lead hole 12 a. However, the present invention is not limited to this, and the lower stepped portion 12 and the upper stepped portion 16 are not provided, and the spacers corresponding to the lower stepped portion 12 and the upper stepped portion 16 are made of an insulating resin to form an inner winding. A configuration may be employed in which the lead wire 25a of the inner winding 25 is drawn from the lower portion of the rod-shaped magnetic body 30 without providing the lead hole 12a.

  In Embodiment 1 described above, the magnetic body 30 has a total of five surfaces including a lower end surface of the lower portion including a portion fitted to the lower magnetic body positioning portion 14c and four surfaces adjacent to the lower end surface. However, the present invention is not limited to this. That is, the surface of the magnetic body 30 that is in direct contact with the lower magnetic body positioning portion 14c only needs to be covered with the insulating tape 31, and the surface facing outward of the bobbin 10 is not covered when attached to the bobbin 10. May be.

  In the embodiment, the inner winding is a primary coil and the outer winding is a secondary coil, but the inner winding may be a secondary coil and the outer winding may be a primary coil.

[Embodiment 2]
The second embodiment is different from the first embodiment in the configuration in which the insulating region is provided in the magnetic material, and the other points are the same as the first embodiment. In the following description of the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  FIG. 10 is a perspective view illustrating a state in which a magnetic body is incorporated in the bobbin in the transformer according to the second embodiment. FIG. 11 is a perspective view illustrating a main part in a state where a magnetic body is incorporated in a bobbin in the transformer according to the second embodiment.

  In the transformer 1A according to the second embodiment, the magnetic body 30A incorporated in the bobbin 10A is different from the magnetic body 30 of the first embodiment in that it is not covered with the insulating tape 31. As shown in FIGS. 10 and 11, the magnetic body 30 </ b> A includes the upper magnetic body positioning portion 18 a and the front side in a state where an insulating member 31 </ b> A formed using a thermoplastic resin such as LCP (Liquid Crystal Polymer) is attached. It is attached to the bobbin 10A so as to be fitted to the lower magnetic body positioning portion 14cA of the leg portion 14A.

  The insulating member 31A includes an upper insulating member 31-1A and a lower insulating member 31-2A. The upper insulating member 31-1A covers the back surface of the magnetic body 30A on the inner interline tape 20 side and both side surfaces adjacent to the back surface, and, like the magnetic body 30 of the first embodiment, an inner winding (not shown). ) To secure an insulation distance between the lead wire (not shown) and the outer winding (not shown).

  Specifically, as shown in FIG. 11, in the transformer 1 </ b> A of the second embodiment, the creepage distance between the lead wire (not shown) of the inner winding (not shown) and the outer winding (not shown). (Spatial distance) is (α ′ + β ′).

  Here, as shown in FIG. 11, the creepage distance α ′ is equal to the creepage distance α1 ′ where the upper insulating member 31-1A is in contact with the inner interline tape 20 in the vicinity of the extraction hole slit 12bA and the upper insulating member 31-1A. It is the sum of the creepage distance α2 ′ corresponding to the thickness (that is, α ′ = α1 ′ + α2 ′). That is, the creepage distance α ′ is an insulation distance between the inner winding (not shown) and the inner line tape 20 and the outer inter-line tape (not shown) and the outer winding (not shown). .

  Further, as shown in FIG. 11, the creepage distance β ′ is a creepage distance β1 ′ corresponding to the height of the upper insulating member 31-1A and a creepage distance β2 ′ corresponding to the height of the lower insulating member 31-2A. Is the insulation distance. Further, the creepage distance β is the sum of the outer winding 26 and the lower core 61 (that is, β ′ = β1 ′ + β2 ′). The creeping distance β ′ is also an insulation distance between the outer winding (not shown) and the lower core 61 (see FIG. 1).

  Therefore, according to the second embodiment, in the transformer 1A, the insulation distance between the lead wire (not shown) of the inner winding (not shown) and the outer winding (not shown) is further increased by the creeping distance α ′. It can be secured for a long time. Therefore, by appropriately setting the lengths α ′ and β ′ in the transformer 1A, the transformer 1A can be reduced in size while ensuring the creepage distance and improving the insulation performance.

  Each part of the transformers 1 and 1A according to the above-described first and second embodiments may be appropriately integrated or distributed according to the design. In addition, transformers configured by appropriately combining, replacing, or omitting the respective parts of the transformers 1 and 1A according to the above-described first and second embodiments and their modifications are also included in the transformer according to the disclosed technology.

1,1A Transformer 10, 10A Bobbin 11 Winding trunk 12 Lower step 12a Inner winding lead holes 12b, 12bA Lead hole slit 13 Lower flange 14, 14A Front leg 14a Front pin 14b Lower front core restricting part 14c, 14cA Lower Magnetic body positioning portion 15 Rear leg portion 15a Rear pin 15b Lower rear core regulating portion 16 Upper stepped portion 17a Bobbin hole 17 Upper flange 18 Upper front core regulating portion 18a Upper magnetic body positioning portion 19 Upper rear core regulating portion 20 Inner wire tape 21 Outer wire tape 22 Barrier tape 23 Barrier tape 24 Outer surface tape 25a Lead wire 25 Inner winding 26 Outer winding 30, 30A Magnetic body 31 Insulating tape 31A Insulating member 31-1A Upper insulating member 31-2A Lower insulating member 40 Coil portion 61 Lower core 62 Upper core 63 Loop

Claims (6)

An electric wire is wound around the winding drum to form a second coil on the outer periphery of the first coil and the first coil, and a first brim and a second hook provided at both ends of the winding drum. A bobbin having a buttock;
A rod-shaped magnetic body disposed between the first flange and the second flange between the first coil and the second coil;
And a core arranged so as to surround the outer periphery of the bobbin. A first step portion provided in a peripheral portion of the winding drum portion connected to the first flange portion;
A second step portion provided on a peripheral portion of the winding drum portion connected to the second flange portion,
The transformer according to claim 1, wherein the first step portion and the second step portion position a winding position of the electric wire in the winding body portion of the first coil. The first step portion further includes a lead hole for drawing a lead wire of the first coil along a cylinder axis direction of the winding body portion in a first abutting portion that abuts the magnetic body. The transformer according to claim 2, wherein: The transformer according to claim 3, wherein an insulating member that insulates the magnetic body from the lead wire is disposed on one end side of the magnetic body including the first contact portion. . An insulating member that insulates the magnetic body and the lead wire between the one end side of the magnetic body including the first contact portion and the first flange and the first coil; The transformer according to claim 3, wherein the transformer is provided. The first coil and the second coil are respectively connected to the first contact portion and the second contact portion of the second step portion where the second step portion contacts the magnetic body. The magnetic material positioning part which positions the position where the said magnetic body is arrange | positioned over the said 1st collar part and the said 2nd collar part between layers with a coil is provided, The any one of Claims 3-5 characterized by the above-mentioned. The transformer according to claim 1.

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