JP2019102496A - Coil device - Google Patents

Abstract

To provide a coil device which achieves excellent heat radiation characteristics and can be mounted on another device with good accuracy.SOLUTION: A coil device has: a bobbin around which a wire is wound; a case which houses the bobbin and is attached to an exterior; a resin filling a gap between the bobbin and the case; and a terminal part fixed to the case and connected with the wire.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a coil device that can be suitably used, for example, as a transformer such as a leakage transformer.

  Coil devices are used in various applications for various electrical products. For example, a coil device is used in an automotive charger for EV (Electric Vehicle: electric transportation equipment), PHV (Plug-in Hybrid Vehicle) or commuter (vehicle), LLC circuit, etc. It is generally used as a transformer such as a transformer.

  As a coil device, for example, a coil device shown in Patent Document 1 shown below is known. In the coil device shown in Patent Document 1, adjustment of leakage characteristics is easy, and it is possible to cope with high frequency while achieving large current.

JP, 2015-65413, A

  In recent years, a technique has been proposed in which the coil device as shown in Patent Document 1 is not directly fixed and used, but is housed in a case filled with a resin and used. By accommodating a bobbin etc. in the case filled with resin, the thermal radiation efficiency of a coil apparatus can rise, and it is possible to suppress a loss etc. However, when the bobbin is accommodated in the case, unlike the conventional coil device in which the bobbin is directly fixed, the positional accuracy of the terminal formed on the bobbin is deteriorated, which causes a problem that the assembly becomes difficult. Moreover, in the conventional coil apparatus which provides a terminal in a bobbin, there exists a problem also in the viewpoint of size reduction.

  The present invention has been made in view of such a situation, and an object thereof is to provide a coil device which is excellent in heat dissipation characteristics and can be accurately mounted on another device.

In order to achieve the above object, a coil device according to the present invention is:
A bobbin wound with a wire;
A case that accommodates the bobbin and is attached to the outside;
A resin filled in a gap between the bobbin and the case;
And a terminal portion fixed to the case and to which the wire is connected.

  In the coil device according to the present invention, since the bobbin is accommodated in the case filled with resin, the heat dissipation is excellent, and since the terminal portion is fixed to the case attached to the outside, the coil device is different from other devices. There is little variation in the position of the terminal when mounted. Therefore, such a coil device is excellent in heat dissipation characteristics, and can be accurately mounted on other devices.

  Further, for example, the case and the terminal portion may be integrally insert-molded.

  Such a coil device has high positional accuracy of the terminal portion and the case, and is easy to manufacture. Further, as compared with the conventional coil device in which the bobbin is provided with the terminal portion by a bolt or the like, it is advantageous also from the viewpoint of downsizing and reduction in height.

Also, for example, the wire may have a first wire and a second wire that is discontinuous with the first wire.
The first wire may form an upper coil and a lower coil which are spaced apart from each other along the winding axis of the bobbin.
The second wire may form a middle coil that is α-wound between the upper coil and the lower coil.
In addition, the first wire may be α-wound around the bobbin so as to form an upper coil and a lower coil which are disposed apart from each other along the winding axis of the bobbin.
The second wire may form a middle coil between the upper coil and the lower coil.

  Such a coil device has a structure in which a middle coil of the second wire is sandwiched between an upper coil and a lower coil of the first wire. Therefore, the coupling between these coils can be increased, and stabilization of leakage characteristics can be facilitated. In addition, it is possible to realize a coil device that can obtain stable leakage characteristics even in a high frequency band. In addition, the middle coil is formed by α-winding on a bobbin, and the α-winding can reduce the number of layers in the winding axis direction even if the number of turns is increased. Contribute to miniaturization and miniaturization. In addition, since the wire is not drawn out from the winding center by making the α winding, the wires do not overlap, which contributes to reducing the height of the coil device.

  The α-winding of the middle coil contributes to stabilization of the leakage characteristics. In addition, it is also easy to make the number of turns of the coil the same between each layer of the upper coil, the middle coil, and the lower coil by making the first wire and the second wire α-winding, and changing the number of turns It is also easy to

  Moreover, the upper coil and the lower coil are continuously formed by the first wire. With such a configuration, it is possible to prevent the current from being biased to one of the upper coil and the lower coil. Since the current is prevented from flowing unevenly, any one of the coils can be prevented from abnormal heat generation. Further, as compared with the case where the upper coil and the lower coil are configured by separate wires, it is possible to shorten the wire length of the first wire constituting the upper coil and the lower coil, and to reduce the copper loss. it can. If the copper loss can be reduced, the efficiency can be improved and the heat generation can be reduced.

  Also, for example, the terminal portion is provided on the side facing the first terminal portion to which the first wire is connected and the side on which the first terminal portion is provided in the case, and the second wire is provided. And a second terminal portion to be connected.

  By providing the first terminal portion and the second terminal portion on one side and the other side of the case, such a coil device can enhance the insulation between the first wire and the second wire. Moreover, since all the terminal parts are being fixed to the case, the positional accuracy of the terminal at the time of mounting is favorable.

  Further, for example, the terminal portion is a terminal fixing portion which is in contact with and fixed to the case in the terminal portion, a wire connecting portion which extends from the terminal fixing portion to one side and to which the wire is connected, and the terminal And an external connection portion extending from the fixing portion to the other side.

  In such a coil device, since the positional accuracy of the external connection portion at the time of mounting is good, it is possible to efficiently and easily perform wiring after mounting. In addition, since the wire connection portion and the external connection portion are provided on different sides with respect to the terminal fixing portion, the work of wiring to the external connection portion can be easily performed after mounting, and the wiring operation to the external connection portion The problem of heat transfer to the wire connection can also be prevented.

  Also, for example, the end of the wire may be fused to the terminal.

  Such a coil device is easy to manufacture and has high reliability regarding the connection between the wire and the terminal portion.

Also, for example, the terminal portion may have a wire connection portion to which the wire is connected,
The wire connection portion may be disposed outside the outer periphery of the case when viewed from above.

  In such a coil device, it is possible to increase the distance between the terminals to improve the insulation property, and by extending the wire connection portion not to the upper side but to the outer side, in wiring work and the like after mounting, It can prevent the problem that the wire connection part gets in the way. Also, the leakage characteristics can be stabilized by extending both ends of the wire in parallel to the outside.

FIG. 1 is a perspective view of a transformer as a coil device according to an embodiment of the present invention. FIG. 2 is a perspective view of the transformer shown in FIG. 1 as viewed from another direction. FIG. 3 is a top view of the transformer shown in FIG. FIG. 4 is an exploded perspective view of the transformer shown in FIG. FIG. 5 is a cross-sectional view of an essential part of the transformer shown in FIG. 6 is a perspective view of a case included in the transformer shown in FIG. FIG. 7 is a perspective view of a terminal portion included in the transformer shown in FIG. FIG. 8 is a perspective view of a bobbin and an insulating cover included in the transformer shown in FIG. FIG. 9 is an exploded perspective view showing an upper coil, a lower coil, and a middle coil included in the transformer shown in FIG. FIG. 10 is a side view of the upper coil, the lower coil and the middle coil included in the transformer shown in FIG. FIG. 11 is a circuit diagram showing an equivalent circuit of the transformer shown in FIG.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings.

  Transformer 10 as a coil device according to the present embodiment shown in FIG. 1 is, for example, an automotive vehicle for EV (Electric Vehicle: electric transportation equipment), PHV (Plug-in Hybrid Vehicle: plug-in hybrid vehicle), or commuter (vehicle) It is used for a battery charger etc., and is used, for example, to constitute a part of LLC circuit.

  As shown in FIG. 4 which is an exploded perspective view, the transformer 10 includes a bobbin 20, magnetic cores 40a and 40b, a side cover 50, a pedestal 86, and a case 90 for housing these (see FIG. 3). , Bottom plate 92, and terminal portion 70. Moreover, although illustration is abbreviate | omitted in FIG. 4, the transformer 10 has the coil 300 formed of the 1st wire 38 and the 2nd wire 37 wound around the bobbin 20 (FIG. 9). In the drawings, the X axis, the Y axis, and the Z axis are perpendicular to one another, and the Z axis corresponds to the height (thickness) of the transformer 10. In the present embodiment, the lower side in the Z-axis direction of the transformer 10 is the installation surface of the transformer. The Y axis coincides with the minor axis direction of the elliptical bobbin 20. Furthermore, the X-axis coincides with the long axis direction of the bobbin 20.

  In the present embodiment, as shown in FIGS. 2 and 6, the bottom plate 92 is attached to the bottom opening of the case 90 by means such as caulking or adhesion. As shown in FIG. 6, the upper opening of the case 90 is open. The bottom plate 92 is preferably made of a metal such as aluminum copper or iron having excellent heat dissipation, but may be made of a resin such as PPS, PET or PBT. The bottom plate 92 is preferably made of a material excellent in heat dissipation, because the lower end surface of the magnetic core 40b described later in the Z-axis direction is in contact with or in proximity to the bottom plate 92 directly or through a resin. Below the case 90, a cooling device such as a cooling pipe or a cooling fin may be attached via the bottom plate 92 or directly. The case 90 and the bottom plate 92 may be separate as shown in FIG. 4, but may be integrally formed.

  As shown in FIGS. 2 and 6, the case 90 has a rectangular cylindrical outer shape that is substantially rectangular when viewed from the Z-axis direction, and the case 90 is an external such as a substrate or a frame to which the transformer 10 is fixed. Attached to the The case 90 may have a mounting portion for directly fixing the case 90 to the outside. The mounting portion for directly fixing the case 90 to the outside may have a structure for providing a fixing member such as a bolt, such as a bolt hole or a notch extending in the Z-axis direction, for fixing the case 90. It may be a structure such as a fixed surface or an adhesive surface. The case 90 may be made of synthetic resin or the like, or may be made of metal. The bottom plate 92 and the case 90 may be integrally molded of a resin material by resin molding or the like. As shown in FIGS. 1 and 2, a terminal portion 70 (see FIG. 7) to which a wire consisting of a first wire 38 and a second wire 37 is connected is fixed to the case 90. The terminal portion 70 will be described later.

  As shown in FIG. 3 etc., a resin 88 for heat dissipation is provided in the inside of the case 90, more specifically, in the gap between the bobbin 20 and the magnetic cores 40a and 40b accommodated in the case 90 and the inner surface of the case 90. It is filled. The resin 88 for heat dissipation is not particularly limited, but a resin excellent in heat dissipation having a thermal conductivity of 0.5 to 5, preferably 1 to 3 W / m · K, for example, is preferable. Examples of the resin 88 excellent in heat dissipation include silicone resins, urethane resins, epoxy resins and the like, among which silicone resins and urethane resins are preferable. Moreover, in order to improve heat dissipation, the resin 88 may contain a filler with high thermal conductivity.

  The resin 88 for heat dissipation of this embodiment preferably has a Shore A hardness of 100 or less, preferably 60 or less. Even if the magnetic cores 40a and 40b and the bobbin 20 are deformed by heat, the deformation is absorbed to prevent excessive stress from being generated in the magnetic cores 40a and 40b. A potting resin is illustrated as such resin.

  As shown in FIG. 5 which is a cross-sectional view of the transformer 10 excluding the case 90 and the resin 88, a coil 300 formed by the first wire 38 and the second wire 37 is wound on the bobbin 20 housed in the case 90. It is 9 and 10 show the first wire 38 and the second wire 37 of the transformer 10, respectively. FIG. 10 is a side view of the arrangement of the first wire 38 and the second wire 37 in the transformer 10. FIG. 9 offsets the first wire 38 and the second wire 37 in the X direction with respect to the arrangement in the transformer 10 so that the shapes of the first wire 38 and the second wire 37 can be easily understood. It is a perspective view displayed.

  As shown in FIGS. 9 and 10, the transformer 10 has two wires of a first wire 38 and a second wire 37 which is discontinuous with the first wire 38. The first wire 38 and the second wire 37 are wound around the bobbin body 21 of the bobbin 20 to form a coil 300. The coil 300 has an upper coil 301, a lower coil 302, and a middle coil 303 located between the upper coil 301 and the lower coil 302.

  As shown in FIG. 9, the first wire 38 forms an upper coil 301 and a lower coil 302 which are spaced apart from each other along a winding axis parallel to the Z-axis direction. The second wire 37 forms a middle coil 303 between the upper coil 301 and the lower coil 302, and the middle coil 303 is arranged along the winding axis (in the Z-axis direction) of the coil 300 to form the upper coil 301 and the lower coil. It is sandwiched by the coil 302.

  In the present embodiment, the upper coil 301 and the lower coil 302 of the first wire 38 constitute a primary coil, and the middle coil 303 of the second wire 37 constitutes a secondary coil. That is, as shown in FIG. 11, the upper coil 301 and the lower coil 302 formed by the first wire 38 are the primary winding, and the middle coil 303 formed by the second wire 37 is the secondary winding. Thus, a transformer is formed between the two.

  In the present embodiment, a high voltage acts on the primary coil as compared to the secondary coil, and a relatively low voltage acts on the secondary coil. Here, La shown in FIG. 11 is a leakage inductance.

  The first wire 38 and the second wire 37 may each be configured as a single wire, or may each be configured as a stranded wire, or one may be a single wire and the other may be a stranded wire. The first wire 38 and the second wire 37 may be made of the same material or may be different. The outer diameters of the first wire 38 and the second wire 37 are not particularly limited, but preferably in the range of 1.0 to 4.0 mm. For example, when the current flowing through the secondary coil increases, the outer diameter of the second wire 37 forming the secondary coil is larger than the outer diameter of the first wire 38 forming the primary coil, for example, 3.0 to 4.0 mm is preferable. Further, it is preferable that the first wire 38 and the second wire 37 be a coated wire coated with an insulating coating.

  The first lead portions 38a and 38b shown in FIGS. 1 and 2 are both ends of the first wire 38 shown in FIGS. As shown in FIG. 9, the first lead portion 38 a is drawn from the lower coil 302, and the first lead portion 38 b is drawn from the upper coil 301. As shown in FIG. 1, the first lead portions 38 a and 38 b are routed around the wire guide 23 of the bobbin 20 and then connected to first terminal portions 76 and 78 fixed to the case 90.

  The second leads 37a and 37b shown in FIGS. 1 and 2 are both ends of the second wire 37 shown in FIGS. As shown in FIG. 9, the second lead portions 37 a and 37 b are drawn out from the middle coil 303. As shown in FIG. 1, the second lead portions 37a and 37b are disposed on the wire guide stand 22 opposite to the wire guide stand 23 on which the first lead portions 38a and 38b are drawn, with the core 40 interposed therebetween. , And then connected to the second terminal portions 72 and 74 fixed to the case 90.

  As shown in FIG. 9, in the present embodiment, the total number of turns n1 of the first wires 38 in the upper coil 301 and the lower coil 302 and the total number of turns n2 of the second wires 37 constituting the middle coil 303 are equal. There is. However, n1 and n2 may be different, for example, n1> n2 or n1 <n2. In this embodiment, even when the ratio (n1 / n2) of the number of turns is large or small, the coupling coefficient can be made relatively large, which contributes to the stabilization of the leakage characteristic.

  The total number of turns n1 of the upper coil 301 and the lower coil 302 formed by the first wire 38 is preferably divided substantially equally into the upper coil 301 and the lower coil 302, but may be slightly different. That is, the number of turns of the first wire 38 in the upper coil 301 is preferably (0.3 to 0.7) × n1, and the number of turns of the first wire 38 in the lower coil 302 is (0.7 to It is preferable that it is 0.3) x n1. This is to improve the coupling coefficient between the primary coil and the secondary coil.

  As shown in FIG. 10, the first wire 38 has a first inter-coil connection portion 380 which is wound between the upper coil 301 and the lower coil 302 and extends in the axial direction (Z-axis). In the present embodiment, since the upper coil 301 and the lower coil 302 are continuously formed by the first wire 38, the first wire 38 is wound between the upper coil 301 and the lower coil 302 and extends in the axial direction. The first inter-coil connection portion 380 is formed.

  As shown in FIG. 10, the first inter-coil connection portion 380 passes through the inner diameter side of the middle coil 303. Although details will be described later, in the present embodiment, first, the first wire 38 is wound around the bobbin 20 to form the upper coil 301 and the lower coil 302, and then the second wire 37 is wound around the bobbin 20, A middle coil 303 is formed.

  As described above, by winding the second wire 37 around the bobbin 20 after winding the first wire 38 around the bobbin 20, the first inter-coil connection portion 380 has an inner diameter not the outer diameter side of the middle coil 303. Pass by the side. As shown in FIG. 5, the first insulating cover 81 is attached to the bobbin 20 in order to insulate the first inter-coil connection portion 380 from the middle coil 303. The first insulating cover 81 will be described in detail later.

  As shown in FIG. 10, the second wire 37 has a second inter-coil connection portion 370 which is wound between the first and second layers of the middle coil 303 and extends in the axial direction (Z-axis). In the present embodiment, since the first and second layers of the middle coil 303 are continuously formed by the second wire 37, the second wire 37 includes the first and second layers of the middle coil 303. A second inter-coil connection portion 370 extending in the winding axial direction is formed between them.

  As shown in FIG. 9, in the second wire 37, the second lead portion 37a is drawn from the first layer (upper layer) of the middle coil 303, and the second lead portion from the second layer (lower layer) of the middle coil 303 37b is pulled out.

  More specifically, as shown in FIG. 9, the second lead portions 37a and 37b formed at both ends of the second wire 37 are raised portions 371a and 371b extending in the winding axis (Z axis) direction of the coil 300. And the upper wire portions 372 b, 372 b extending substantially horizontally from the wire guide 22 and the wire guide 22 to the second terminal portions 72, 74. The rising portions 371a and 371b may not necessarily be parallel to the Z axis but may be inclined.

  The distance between the upper wire portions 372 b and 372 b and the distance between the rising portions 371 a and 371 b can be changed according to the characteristics required for the transformer 10. For example, the leakage of the secondary coil can be adjusted by the distance between the upper wire portions 372b and 372b and the gap between the rising portions 371a and 371b.

  On the other hand, as shown in FIG. 9, in the first wire 38, the first lead portion 38b is drawn from the upper coil 301, and the first lead portion 38a is drawn from the lower coil 302, respectively. The first lead portions 38a and 38b formed at both ends of the first wire 38 have first raised portions 381a and 381b extending in the winding axis (Z-axis) direction of the coil 300, and the wire guide 22 and the wire guide 22 Upper wire portions 382 b and 382 b extend in a substantially horizontal direction up to the first terminal portions 76 and 78. The rising portions 381a and 381b may not necessarily be parallel to the Z axis but may be inclined.

  Also with regard to the first wire 38, it is possible to change the distance between the upper wire portions 382b and 382b and the distance between the rising portions 381a and 381b according to the characteristics required for the transformer 10. For example, the leakage of the primary coil can be adjusted by the distance between the upper wire portions 382 b and 382 b and the gap between the rising portions 381 a and 381 b.

  As shown in FIG. 8, the bobbin 20 has a bobbin body 21 and wire guide bases 22 and 23 integrally formed on upper ends of both ends of the bobbin body 21 in the X-axis direction. The bobbin 20 is made of, for example, a plastic such as PPS, PET, PBT, LCP, or nylon, but may be made of other insulating members. However, in the present embodiment, the bobbin 20 is preferably made of, for example, a plastic having a high thermal conductivity of 1 W / m · K or more, and is made of, for example, PPS, nylon or the like.

  The wire guide 22 provided at the upper end portion on the X axis negative direction side of the bobbin 20 has a side wall portion 221 and an engagement protrusion portion 224. The side wall portion 221 is formed to surround the periphery of the wire guide base 22 except for the X-axis negative direction side from which the second lead portions 37 a and 37 b are drawn out. As shown in FIG. 3 which is a top view, the side wall portion 221 can increase the insulation distance between the magnetic core 40a and the second lead portions 37a and 37b. A separation protrusion 223 is formed in the wire guide 22 at an intermediate position in the Y-axis direction of the pair of engagement protrusions 224. The separation convex portion 223 can prevent the both ends of the second wire 37 (see FIG. 8) from being short circuited by separating the second lead portion 37a and the second lead portion 37b.

  As shown in FIGS. 3 and 9, the second lead portions 37a and 37b, which are raised in the Z-axis direction by the rising portions 371a and 371b, are provided on the pair of engagement protrusions 224 of the upper wire portions 372a and 372b. The part is wound inside from the X-axis negative direction side, is guided passing between the engagement protrusion 224, the side wall part 221 and the separation convex part 223, and is folded back again in the X-axis negative direction. By folding back the second lead portions 37a and 37b in the X-axis direction in the wire guide base 22, unrolling of the middle coil 303 (see FIG. 9) can be prevented during manufacturing or the like.

  Furthermore, as shown in FIGS. 1 and 3, the second lead portions 37 a and 37 b are routed from the wire guide 22 to the second terminal portions 72 and 74 fixed to the case 90 surrounding the outer periphery of the bobbin 20. , And fixed to the wire connection portions 72 b and 74 b of the second terminal portions 72 and 74.

  The wire guide 23 provided at the upper end portion of the bobbin 20 in the positive X-axis direction also has a side wall portion 231 and an engagement protrusion 234 similarly to the wire guide 22. As shown in FIG. 3, the shape of the wire guide 23 is asymmetrical to the shape of the wire guide 22, but the shapes of the wire guides 22 and 23 are not limited to those shown in the embodiment, and they are mutually It may have a symmetrical shape.

  The side wall portion 231 of the wire guide 23 is formed so as to surround the periphery of the wire guide 23 except for the X-axis positive direction side from which the first leads 38a and 38b are drawn. Similar to the side wall portion 221 of the wire guide base 22, the side wall portion 231 can increase the insulation distance between the magnetic core 40a and the first lead portions 38a and 38b. In the wire guide 23, a separation protrusion 233 is formed at an intermediate position in the Y-axis direction of the pair of engagement protrusions 234. The separation convex portion 233 can prevent the both ends of the first wire 38 (see FIG. 9) from being short circuited by separating the first lead portion 38a and the first lead portion 38b.

  As shown in FIGS. 3 and 9, the first lead portions 38a and 38b raised in the Z-axis direction by the rising portions 381a and 381b are provided on the pair of engagement protrusions 234 of the upper wire portions 382a and 382b. The part is wound from the X-axis positive side to the inside (rolling shaft side), is guided passing between the engagement protrusion 234, the side wall part 231 and the separation convex part 233, and is folded back to the X-axis positive direction again. Be By folding back the first lead portions 38a and 38b in the X-axis direction in the wire guide base 23, unrolling of the upper and lower coils 301 and 302 (see FIG. 9) can be prevented during manufacture or the like.

  Furthermore, as shown in FIGS. 2 and 3, the first lead portions 38 a and 38 b are routed from the wire guide 23 to the first terminal portions 76 and 78 fixed to the case 90 surrounding the outer periphery of the bobbin 20. , And fixed to the wire connection portions 76b and 78b of the first terminal portions 76 and 78, respectively.

  As shown in FIGS. 5 and 8, end partition ridges 24 and 25 extend radially outward at both ends in the Z-axis direction of the winding cylindrical portion 28 included in the bobbin main body 21 of the bobbin 20. , And are integrally molded substantially parallel to the XY plane. On the outer peripheral surface of the wound cylindrical portion 28 located between the end partition wall ridges 24 and 25 in the Z-axis direction, a first wound partition wall ridge 26a constituting the wound partition wall ridge 26 and a second wound partition wall ridge 26b and the third winding partition wall 26c are formed at predetermined intervals in the Z-axis direction so as to project radially outward. The first to third wound partition walls 26a to 26c formed between the end partition walls 24 and 25 are shown in FIG. Such sections S1 to S4 are formed. In addition, the number of winding partition rib 26a-26c and division S1-S4 is not specifically limited.

  As shown in FIG. 5, in the sections S1 and S4, the upper coil 301 and the lower coil 302 are formed by continuously winding the first wire 38 for several turns (5 T in FIG. 5). In the sections S2 and S3, the second wire 37 is continuously wound by several turns (5 T in FIG. 5) to form a middle coil 303. In the present embodiment, the first winding partition wall 26a serves to divide the upper coil 301 and the first layer of the middle coil 303 wound in the section S3 in the Z-axis direction. Further, the second winding partition wall 26b serves to divide the first layer of the middle coil 303 wound in the section S3 and the second layer of the middle coil 303 wound in the section S2 in the Z-axis direction . In addition, the third winding partition wall 26c serves to divide the lower coil 302 and the second layer of the middle coil 303 wound in the section S2 in the Z-axis direction.

  As shown in FIG. 5, the section width T1 along the Z-axis in the sections S1 and S4 in which the first wire 38 forming the upper coil 301 and the lower coil 302 is wound is one first in the Z-axis direction. The width is set so that the 1 wire 38 can enter. However, the section width T1 may be set to a width in which two or more first wires 38 can enter in the Z-axis direction. Further, in the present embodiment, the division widths T1 are preferably all the same, but may be slightly different.

  Further, the section width T2 along the Z axis in the sections S2 and S3 in which the second wire 37 constituting the middle coil 303 is wound is set to a width in which one second wire 37 can enter in the Z axis direction. It is However, the section width T2 may be set to a width in which two or more second wires 37 can enter in the Z-axis direction. Furthermore, in the present embodiment, the section width T2 along the Z axis in the sections S2 and S3 is preferably different from the section width T1 in accordance with the wire diameter of the second wire 37, but is the same. It is also good.

  In the present embodiment, the winding method of the first wire 38 wound in the sections S1 and S4 is α winding, and from the first inter-coil connection portion 380 shown in FIG. 10, each section S1 and S4 shown in FIG. The first wire 38 is passed through to start winding, and after forming the lower coil 302 and the upper coil 301 in each of the sections S1 and S4, they are drawn out to the first lead portions 38a and 38b shown in FIG. For this reason, as shown in FIGS. 5 and 10, the innermost layer of the upper coil 301 and the innermost layer of the lower coil 302 are connected by the first inter-coil connection portion 380. Further, as shown in FIG. 9, the first lead portion 38 b is drawn from the outermost layer of the upper coil 301, and the first lead portion 38 a is drawn from the outermost layer of the lower coil 302.

  Further, in the present embodiment, the winding method of the second wire 37 wound in the sections S2 and S3 is also α winding, and from the second inter-coil connection portion 370 shown in FIG. 10, each section S2 shown in FIG. And, the second wire 37 is passed through and started to be wound at S3, and after the middle coil 303 is formed in each of the sections S2 and S3, it is drawn out to the second lead portions 37a, 37b shown in FIG. Therefore, as shown in FIGS. 5 and 10, the innermost layer of the middle coil 303 of the section S2 and the innermost layer of the middle coil 303 of the section S3 are connected by the second inter-coil connection portion 370. Further, as shown in FIG. 9, the second lead portion 37b is drawn from the outermost layer of the middle coil 303 of the section S2, and the second lead portion 37a is drawn from the outermost layer of the middle coil 303 of the section S3.

  Here, the alpha winding will be described. For example, in order to α-wind the first wire 38 on the bobbin 20 shown in FIG. 8, first, a portion where the circumferential direction part of the winding partition wall 26 is cut away (X-axis negative direction side of the bobbin main body 21 At the end portion, through the first inter-coil connection portion 380 of the first wire 38, the sections S1 and S4 shown in FIG. 5 are communicated with each other. Then, a part of the first wire 38 on the side close to the first lead portion 38a is wound around the outer periphery of the winding cylindrical portion 28 in the clockwise direction, for example, in the section S4. The other part of the first wire 38 on the side closer to the first lead portion 38b is a winding cylinder inside the section S1 in a direction (or the same direction) opposite to the winding direction in the section S1. It is wound around the outer periphery of the portion 28. Note that these operations may be performed using an automatic winding machine.

  The second wire 37 wound in the sections S2 and S3 shown in FIG. 5 is a portion where a part in the circumferential direction of the wound partition wall 26 is cut out (an end on the X axis positive direction side in the bobbin main body 21) Before and after disposing the second inter-coil connection portion 370 of the second wire 37, the first insulating cover 81 is attached to the bobbin main body 21. After the first insulating cover 81 is attached, a part of the second wire 37 on the side close to the second lead portion 37a is wound around the outer periphery of the winding cylindrical portion 28 in the clockwise direction, for example, inside the section S3. At the same time, the other part of the second wire 37 closer to the second lead portion 37b is wound in the direction opposite to (or may be the same as) the winding direction in the section S3 in the section S2. It is wound around the outer periphery of the portion 28. Note that these operations may be performed using an automatic winding machine.

  As shown in FIG. 8, bobbin legs 29 are integrally formed on both ends in the X-axis direction of the end partition rib 25 located at the lowermost part in the Z-axis direction. Each bobbin leg 29 is formed so as to protrude downward in the Z-axis direction from both ends in the X-axis direction of the end partition rib 25. Each bobbin leg 29 accommodates each pedestal 86 shown in FIG.

  As shown in FIG. 8, on the side of the wire guide 22 of the first to third wound partition walls 26a, 26b, 26c, a notch 264a, having a width narrower than the width in the Y-axis direction of the first insulating cover 81. 264b and 264c are formed. Further, on the lower surface of the first wound partition wall 26a in the Z-axis direction, a counterbored surface 261a which is not penetrated in the Z-axis direction is formed at a circumferential position where the notch portion 264a is formed. Further, on the upper surface in the Z-axis direction of the third winding partition wall 26c, a counterbored surface 261c which is not penetrated in the Z-axis direction is formed at a circumferential position where the notch portion 264c is formed.

  A first insulating cover 81 is attached between the first wound partition wall 26a and the third wound partition wall 26c along the counterbore surfaces 261a and 261c so as to close the notches 264a and 264c. As shown in FIG. 5, the first insulating cover 81 is, for example, for insulating the first inter-coil connection portion 380 from the middle coil 303.

  As shown in FIG. 8, the first insulating cover 81 includes a first partial ridge 811, a second partial ridge 812, an intermediate partial ridge 813, an upper partial ridge 814, and an intermediate partial cylinder 815 (FIG. 5 together And vertical portion 816).

  As shown in FIG. 5, the middle partial cylinder 815 constitutes a part of a cylinder around which the second wire 37 is wound. In addition, as shown in FIG. 5 which is a cross sectional view, the other part of the cylinder is constituted by the winding cylindrical portion 28 of the bobbin 20. That is, the middle partial cylinder 815 is disposed overlapping from the outer diameter side on the overlapping portion 28 a which is a part of the winding cylinder 28 of the bobbin 20, and a non-overlapping portion 28 b which is another portion of the winding cylinder of the bobbin 20. And the innermost layer of the middle coil 303 is wound around the outer periphery of the cylinder. As shown in FIG. 5, the inner circumferential surface of the intermediate partial cylinder 815 faces the outer circumferential surface of the overlapping portion 28 a of the winding cylindrical portion 28 of the bobbin 20 with the first inter-coil connection portion 380 interposed therebetween. As described above, by interposing the first insulating cover 81 such that the first inter-coil connection portion 380 and the second wire 37 (the middle coil 303) are isolated, it is possible to reliably achieve the insulation of the both. .

  As shown in FIGS. 5 and 8, the first partial ridge 811 and the second partial ridge 812 are formed parallel to the XY plane at one end and the other end in the Z-axis direction of the middle partial cylinder 815, respectively. As shown in FIG. 8, counterbored surfaces 811 a are formed at both ends in the Y-axis direction of the upper surface of the first part ridge 811. The counterbore surface 811a has a predetermined Y-axis direction width, and is formed to extend in the X-axis direction by a predetermined distance. The counterbore surface 811a is superposed on and in contact with the counterbore surface 261a of the first winding partition wall 26a. Counterbored surfaces 812 a are formed at both ends in the Y-axis direction of the lower surface of the second part ridge 812. The counterbore surface 812a has a predetermined Y-axis direction width and is formed to extend in the X-axis direction by a predetermined distance. The counterbore surface 812a is superposed on and in contact with the counterbore surface 261c of the third winding partition rib 26c.

  The middle partial ridge 813 is formed parallel to the XY plane at a substantially central portion of the middle partial cylinder 815 in the Z-axis direction so as to be sandwiched between the first partial ridge 811 and the second partial ridge 812. In the illustrated example, the middle portion wedge 813 is divided into two portions, one end in the Y-axis direction and the other end in the Y-axis direction.

  The vertical portion 816 has a predetermined Y-axis width and is formed to extend in the Z-axis direction from the top surface of the first portion ridge 811. The vertical portion 816 has a predetermined width in the Z-axis direction, and protrusions are formed at the central portion of the vertical portion 814 in the Y-axis direction to arrange the rising portions 371a and 371b of the second lead portions 37a and 37b apart Yes. The upper partial weir 814 is connected to the Z-axis positive end of the vertical portion 816 and formed parallel to the XY plane.

  As shown in FIG. 5, the vertical portion 816 is formed to insulate the raised portions 371 a and 371 b of the second lead portions 37 a and 37 b from the first wire 38 passing above the first partial ridge 811. It is As described above, by interposing the first insulating cover 81 such that the second wire 37 (middle coil 303) and the first wire 38 (upper coil 301 and lower coil 302) are separated, insulation of both is achieved. It is possible to plan surely.

  In addition, by arranging the first partial ridge 811 and the vertical portion 816 between the second wire 37 (the first layer of the middle coil 303) and the first wire 38 (the upper coil 301), the transformer 10 is enlarged. Thus, the creeping distance between the second wire 37 and the first wire 38 can be sufficiently secured.

  In addition, by arranging the second partial ridge 812 between the second wire 37 (the second layer of the middle coil 303) and the first wire 38 (the lower coil 302), the transformer 10 is not increased in size. The creepage distance between the second wire 37 and the first wire 38 can be sufficiently secured.

  As shown in FIG. 5, an upper coil 301 of the first wire 38 is disposed in a region sandwiched by the upper partial ridge 814, the first partial ridge 811 and the end partition ridge 24. As shown in FIG. 5, the upper partial ridge 814 separates the first wire 38 forming the upper coil 301 from the second leads 37 a, 37 b of the second wire 37 passing above the upper partial ridge 814. It has been formed. As described above, by interposing the first insulating cover 81 such that the first wire 38 (upper coil 301) and the second lead portions 37a and 37b of the second wire 37 are separated, insulation between the both is assured. Can be

  In addition, the transformer 10 is disposed by arranging the upper partial ridge 814 between the second lead portions 37a and 37b (upper wire portions 372a and 372b) of the second wire 37 and the first wire 38 (upper coil 301). The creeping distance between the second leads 37 a and 37 b of the second wire 37 and the first wire 38 can be sufficiently secured without increasing the size of the second wire 37.

  As shown in FIG. 8, in the first insulating cover 81, the counterbore surface 811a of the first partial weir 811 abuts the counterbore surface 261a of the first wound partition weir 26a, and the counterbore surface 812a of the second partial weir 812 is the first It abuts on the counterbore surface 261c of the three-turn bulkhead 26c and is fixed to the bobbin 20 so as to be slide-insertable. As shown in FIG. 5, in the present embodiment, the first inter-coil connection portion 380 passes inside the middle coil 303, but as shown in FIG. 5, the first inter-coil connection portion 380 and the middle coil 303 and Is reliably insulated by the middle part cylinder 815 of the first insulating cover 81.

  Also, a notch (see FIG. 5) is formed on the wire guide 23 side of the first and third wound partition walls 26a and 26c so that the second insulating cover 82 shown in FIG. 8 can be attached. . As shown in FIG. 5, the second insulating cover 82 insulates the upstanding portion 381 a of the first lead portion 38 a of the first wire 38 from the middle coil 303, and the middle coil 303 from the upper coil 301 and the lower coil 302. It is for insulation.

  As shown in FIG. 8, the second insulating cover 82 has a first partial ridge 821 and a second partial ridge 822 formed in parallel in the XY axis plane at both ends in the Z-axis direction, and a wall 823 . As shown in FIG. 5, the second insulating cover 82 is a notch in which the first and second partial ridges 821 and 822 are formed in the first and third wound partition ridges 26 a and 26 c on the wire guide 23 side. By inserting the first and second partial ridges 821 and 822 into contact with the counterbored surfaces formed on the first and third wound partition ridges 26a and 26c on the wire guide 22 side, It is fixed to the bobbin 20.

  As shown in FIG. 5, the rising portion 381 a and the middle coil are separated so that the first lead portion 38 a (the rising portion 381 a) of the first wire 38 is separated from the middle coil 303 on the way to being drawn upward By interposing the second insulating cover 82 between it and 303, it is possible to ensure the insulation between the two.

  In addition, the second insulating cover 82 is interposed between the upper coil 301 and the lower coil 302 and the middle coil 303 so that the upper coil 301 and the lower coil 302 and the middle coil 303 are isolated from each other. Can be assured.

  The first and second insulating covers 81 and 82 are made of an insulating member such as plastic similar to or different from the bobbin 20. The insulating covers 81 and 82 are formed separately from the bobbin 20 and attached to a part of the bobbin 20 in the circumferential direction.

  The magnetic cores 40a and 40b shown in FIG. 4 have the same shape in this embodiment, have an E-shaped cross section in the ZY cross section, and constitute a so-called E-shaped core. The magnetic cores 40a and 40b are divided cores formed by cutting in parallel to the XZ plane, but the magnetic cores 40a and 40b are not limited to only the divided cores. Further, the shapes of the magnetic cores 40a and 40b are not limited to only the E-shaped core, and magnetic cores of other shapes may be used.

  As shown in FIG. 4, when the magnetic cores 40a and 40b are divided cores, the gap between the portion covering the upper surface of the core 40a and the divided cores 40a and 40b (middle legs 46a and 46b) is taken as the Z axis. A top plate for heat dissipation may be provided on the magnetic cores 40a and 40b, the top plate including a portion extending downward in the direction. Thereby, the heat dissipation of the transformer 10 can be effectively improved.

  As shown in FIG. 4, the magnetic core 40a disposed on the upper side in the Z-axis direction includes a base portion 44a extending in the Y-axis direction and a pair of magnetic cores 40a projecting in the Z-axis direction from both ends in the Y-axis direction of the base portion 44a. A side leg 48a and an intermediate leg 46a protruding between the side legs 48a in the Z-axis direction from the center in the Y-axis direction. The magnetic core 40b disposed on the lower side in the Z-axis direction includes a base portion 44b extending in the Y-axis direction, and a pair of side leg portions 48b projecting in the Z-axis direction from both ends in the Y-axis direction of the base portion 44b. Between the side legs 48b, there is a middle leg 46b projecting in the Z-axis direction from the center in the Y-axis direction.

  The middle leg portion 46 a is inserted into the core leg through hole 21 a of the bobbin 20 from the upper side in the Z-axis direction. Similarly, the middle leg portion 46b is inserted into the core leg through hole 21a of the bobbin 20 from the lower side in the Z-axis direction, and the tip of the middle leg portion 46b is configured to face each other in the core leg through hole 21a. It is In the illustrated example, the tip of the middle leg 46b is in contact with the tip of the middle leg 46a in the core leg through hole 21a, but the tip of the middle leg 46a and the middle leg 46b A predetermined gap (not shown) may be formed between it and the tip of the. Thus, by forming the gap, it is possible to adjust the leakage characteristics according to the width of the gap.

  The middle leg portion 46a and the middle leg portion 46b have a substantially elliptic cylindrical shape so as to conform to the inner peripheral surface shape of the core leg through hole 21a, but the shapes are not particularly limited, and the core leg You may change according to the shape of the through-hole 21a. Further, the side legs 48a and 48b have an inner concave curved shape that matches the outer peripheral surface shape of the bobbin main body 21, and the outer surface thereof has a plane parallel to the XZ plane. In the present embodiment, the material of each of the cores 40a and 40b may be a soft magnetic material such as metal or ferrite, but is not particularly limited.

  As shown in FIG. 3, side covers 50 are respectively disposed between the inner peripheral surfaces of the side legs 48 a and 48 b and the outer peripheral surface of the bobbin main body 21. The side cover 50 has a cover main body 52 that covers the outer periphery of the bobbin main body 21 located between the wire guide bases 22 and 23 of the bobbin 20. Lock pieces 54 bent in a substantially vertical direction from the cover main body 52 covering the outer periphery of the bobbin main body 21 are integrally formed at both ends in the Z-axis direction of the cover main body 52 in the side cover 50 It is A pair of locking pieces 54 formed on both sides of the cover main body 52 in the Z-axis direction are attached so as to sandwich the upper and lower surfaces of the bobbin main body 21 in the Z-axis direction.

  Further, side leg guide pieces 56 extending in the Z-axis direction are integrally formed on the outer surfaces of both ends of the cover main body 52 in the X-axis direction. The inner surfaces of the side legs 48a and 48b contact the outer surface of the cover main body 52 located between the pair of side leg guide pieces 56, and movement of the side legs 48a and 48b in the X-axis direction is the pair of side legs It is limited by the guide piece 56. The side covers 50 are made of an insulating member such as plastic similar to the bobbin 20 or metal.

  6 is a perspective view showing a case 90, a bottom plate 92, and a terminal portion 70 fixed to the case 90 included in the transformer 10 shown in FIG. The bobbin 20, the coil 300, and the magnetic cores 40a and 40b described above are accommodated inside the case 90. A first terminal mounting portion 98 and a second terminal mounting portion 97 are respectively formed on a pair of opposing side surfaces of the case 90. The first terminal mounting portion 98 and the second terminal mounting portion 97 are thicker than the other portions of the case 90, and the first terminal mounting portion 98 provided on the side surface in the positive direction of the X-axis is the first terminal The parts 76 and 78 are fixed, and the second terminal parts 72 and 74 are fixed to the second terminal installation part 97 provided on the side surface on the X axis negative direction side.

  FIG. 7 is a perspective view showing the terminal unit 70 fixed to the case 90. As shown in FIG. The terminal portion 70 has four separated metal terminals of two first terminal portions 76, 78 and two second terminal portions 72, 74. Further, the four metal terminals of the first terminal portions 76 and 78 and the second terminal portions 72 and 74 are mutually insulated. Moreover, it is preferable that the 1st terminal parts 76 and 78 and the 2nd terminal parts 72 and 74 are produced with the metal material etc. of a good conductor. The first terminal portions 76 and 78 and the second terminal portions 72 and 74 are insert-molded integrally with the case 90 with the first terminal mounting portion 98 and the second terminal mounting portion 97 of the case 90 as shown in FIG. There is. However, the method of fixing the first terminal portions 76 and 78 and the second terminal portions 72 and 74 to the case 90 is not limited to insert molding, and the first terminal portions 76 and 78 may be formed by other methods such as adhesion or screwing. The second terminal portions 72 and 74 may be fixed to the case 90.

  As shown in FIG. 2, both ends of the first wire 38 are fixed to the first terminal portions 76 and 78. As shown in FIG. 7, the first terminal portion 76 includes a first terminal fixing portion 76 a which is a terminal fixing portion, a first wire connecting portion 76 b which is a wire connecting portion, and a first external connecting portion which is an external connecting portion. And 76c. The first terminal fixing portion 76 a is in contact with and fixed to the first terminal mounting portion 98 in the case 90. Since the first terminal fixing portion 76a is fixed to the case 90 by insert molding, the first terminal fixing portion 76a is embedded in the resin constituting the case 90 in the assembled state as shown in FIGS. 1 and 2.

  The first wire connection portion 76b of the first terminal portion 76 shown in FIG. 7 extends from the first terminal fixing portion 76a to one side, and the first lead portion 38a of the first wire 38 is connected (FIG. 2 and FIG. See Figure 3). The first lead portion 38a which is one end of the first wire 38 is fused (a kind of thermal welding) to the first wire connection portion 76b, but the first wire connection portion 76b of the first lead portion 38a There is no particular limitation on the fixing method.

  The first external connection portion 76c in the first terminal portion 76 shown in FIG. 7 extends from the first terminal fixing portion 76a to the other side, and a wiring path to the outside other than the transformer 10 can be connected. For example, after the transformer 10 is mounted on the first external connection portion 76c, bus bars (conductor bars), wires, etc. are connected by welding or other methods, but the shape of the first external connection portion 76c or the first external The wiring method to the connection part 76c is not limited to the embodiment.

  Similar to the first terminal portion 76, the first terminal portion 78 includes a first terminal fixing portion 78a which is a terminal fixing portion, a first wire connecting portion 78b which is a wire connecting portion, and a first outside which is an external connecting portion. And a connection portion 78c. In the first terminal portion 78, the first lead portion 38b, which is the other end of the first wire 38, is fixed to the first wire connection portion 78b. The first terminal portion 78 has a specific shape different from that of the first terminal portion 76, but the function and schematic structure of each portion are the same, so the description thereof will be omitted. The first terminal 76 and the first terminal 78 may have different shapes as shown in FIG. 7, but even if the first terminal 76 and the first terminal 78 have the same shape. It may well be symmetrical to each other.

  As shown in FIG. 1, both ends of the second wire 37 are fixed to the second terminal portions 72 and 74. As shown in FIG. 7, the second terminal portion 72 includes a second terminal fixing portion 72a which is a terminal fixing portion, a second wire connecting portion 72b which is a wire connecting portion, and a second external connecting portion which is an external connecting portion. And 72c. The second terminal fixing portion 72 a is in contact with and fixed to the second terminal mounting portion 97 in the case 90. The second terminal fixing portion 72a is fixed to the case 90 by insert molding in the same manner as the first terminal fixing portions 76a and 78a. Therefore, the second terminal fixing portion 72a constitutes the case 90 in the assembled state as shown in FIGS. It is embedded inside the resin.

  The second wire connection portion 72b of the second terminal portion 72 shown in FIG. 7 extends from the second terminal fixing portion 72a to one side, and the second lead portion 37a of the second wire 37 is connected (FIG. 1 and FIG. See Figure 3). The second lead portion 37a which is one end of the second wire 37 is fused to the second wire connection portion 72b (a kind of thermal pressure welding), but the second wire connection portion 72b of the second lead portion 37a There is no particular limitation on the fixing method.

  The second external connection portion 72c in the second terminal portion 72 shown in FIG. 7 extends from the second terminal fixing portion 72a to the other side, and a wiring path to the outside other than the transformer 10 can be connected. For example, after mounting the transformer 10, a bus bar (conductor rod) or a wire is connected to the second external connection portion 72c by welding or other method, but the shape of the second external connection portion 72c or the second external portion The wiring method to the connection part 72c is not limited to the embodiment.

  Similar to the second terminal portion 72, the second terminal portion 74 includes a second terminal fixing portion 74a which is a terminal fixing portion, a second wire connecting portion 74b which is a wire connecting portion, and a second outside which is an external connecting portion. And a connection portion 74c. In the second terminal portion 74, the second lead portion 37b, which is the other end of the second wire 37, is fixed to the first wire connection portion 74b. The second terminal portion 74 is different in detailed shape from the second terminal portion 72, but the function and the schematic structure of each portion are the same, so the description thereof will be omitted. The shapes of the second terminal portion 72 and the second terminal portion 74 may be different from each other, may be the same, or may be symmetrical to each other.

  As can be understood from FIG. 3 in which the transformer 10 is viewed from above, the first wire connection portions 76 b and 78 b and the second wire connection portions 72 b and 74 b in the first terminal portions 76 and 78 and the second terminal portions 72 and 74 are , And the outer side of the outer periphery of the case 90 as viewed from above. By thus arranging the first wire connection parts 76b and 78b and the second wire connection parts 72b and 74b outside the outer periphery of the case 90, the insulation of each terminal part is ensured, and the transformer 10 is reduced. It is possible to make it back. The first external connection parts 76c and 78c are disposed outside the outer periphery of the case 90, and the second external connection parts 72c and 74c are disposed inside the outer periphery of the case 90, but the first external connection parts The arrangement of the 76c and 78c and the second external connection portions 72c and 74c is not particularly limited as long as the wiring operation after mounting can be smoothly performed.

  The transformer 10 according to the present embodiment is manufactured by assembling the respective members shown in FIG. 2 and winding the second wire 37 and the first wire 38 around the bobbin 20. Below, an example of the manufacturing method of the transformer 10 is demonstrated using FIG. 4 etc. FIG. In manufacturing the transformer 10, first, the bobbin 20 is prepared. Although the material of the bobbin 20 is not particularly limited, the bobbin 20 is formed of an insulating material such as a resin.

  Next, the first wire 38 is wound around the outer periphery of the wound cylindrical portion 28 of the bobbin 20 by α winding to form the upper coil 301 and the lower coil 302. The first wire 38 used to form the upper coil 301 and the lower coil 302 is not particularly limited, but a litz wire or the like is preferably used.

  Next, the first insulating cover 81 is attached to the bobbin 20 around which the first wire 38 is wound. The first insulating cover 81 may be attached to the bobbin 20 before the first wire 38 is wound around the outer periphery of the bobbin 20.

  Next, the second wire 37 is wound around the outer circumference of the winding cylindrical portion 28 of the bobbin 20 to form the middle coil 303. The second leads 37 a and 37 b are pulled out of the middle coil 303 above the winding shaft and locked to the wire guide 22. The second wire 37 used to form the middle coil 303 may be the same as or different from the first wire 38.

  Further, the second insulating cover 82 is attached to the bobbin 20, and the first lead portions 38a and 38b are pulled out of the upper coil 301 and the lower coil 302 above the winding shaft and locked to the wire guide stand 23. The second insulating cover 82 may be attached to the bobbin 20 before the first wire 38 is wound around the outer periphery of the bobbin 20.

  Next, the side covers 50 are attached to both sides of the bobbin 20 in the Y-axis direction, and thereafter, the magnetic cores 40a and 40b are attached from the vertical direction of the Z-axis direction. That is, the tips of the side legs 48a and 48b are joined together with gaps as needed between the tips of the middle legs 46a and 46b of the magnetic cores 40a and 40b. Examples of the material of the magnetic cores 40a and 40b include soft magnetic materials such as metal and ferrite, but are not particularly limited.

  Next, the pedestal 86 is housed inside the bobbin leg 29. A pedestal 86 may be attached to the bobbin leg 29 in advance. Furthermore, separately from the bobbin 20 and the magnetic cores 40a and 40b, a case 90 (see FIG. 6) to which the first terminal portions 76 and 78 and the second terminal portions 72 and 74 are fixed is prepared. The case 90 to which the first terminal portions 76 and 78 and the second terminal portions 72 and 74 are fixed is made, for example, by insert molding. The bottom plate 92 is fixed to the bottom opening of the case 90 by adhesion or the like.

  Next, as shown in FIG. 6, the assembly including the bobbin 20, the first wire 38, the second wire 37, the magnetic cores 40a and 40b, etc. is accommodated in a case 90 having an open upper portion, and the case 90 The inside of the is filled with a resin for heat dissipation to form a resin 88. Furthermore, the tips of the first lead portions 38a, 38b are connected to the first wire connection portions 76b, 78b in the first terminal portions 76, 78, and the tips of the second lead portions 37a, 37b are in the second terminal portions 72, 74. The transformer 10 according to the present embodiment is obtained by connecting to the second wire connection parts 72b and 74b.

  The connection between the first lead portions 38a and 38b and the second lead portions 37a and 37b and the first wire connection portions 76b and 78b and the second wire connection portions 72b and 74b is performed, for example, by the following fusing process be able to. That is, in the fusing step, first, the tips of the first lead portions 38a and 38b are temporarily fixed to the first wire connection portions 76b and 78b, and the tips of the second lead portions 37a and 37b are temporarily fixed to the second wire connection portions 72b and 74b Do. The temporary fixing is performed by passing the tips of the first lead portions 38a and 38b and the second lead portions 37a and 37b through the first wire connection portions 76b and 78b and the second wire connection portions 72b and 74b, and the first wire connection portions 76b and 76b. This is performed by sandwiching the first lead portions 38a and 38b and the second lead portions 37a and 37b with the 78b and the second wire connection portions 72b and 74b. There is no need to remove the insulation coating on the tip portions of the first lead portions 38a and 38b and the second lead portions 37a and 37b when performing temporary fixing, and at the stage immediately after the temporary fixing step, the first wire 38 and the second wire The terminal 37 may not be electrically connected to the first terminals 76, 78 and the second terminals 72, 74.

  After the temporary fixing step, the first wire connection portions 76b and 78b and the second wire connection portions 72b and 74b sandwiching the first lead portions 38a and 38b and the second lead portions 37a and 37b with the electrodes (heads) generating heat. By sandwiching, resistance heat generation of the electrodes is transmitted to the first wire connection portions 76 b and 78 b and the second wire connection portions 72 b and 74 b while being crushed, and a thermal pressure welding process (thermal caulking) is performed. In the thermal pressure welding process, the insulation coating on the tip end portions of the first lead portions 38a and 38b and the second lead portions 37a and 37b is a wire inside the first lead portions 38a and 38b and the second lead portions 37a and 37b, and The 1-wire connection portions 76 b and 78 b and the second wire connection portions 72 b and 74 b are removed by resistance heat generation caused by energization. Furthermore, in the thermal pressure welding process, the lead wire exposed by removing the insulation coating on the tip end portions of the first lead portions 38a and 38b and the second lead portions 37a and 37b, and the first wire connection portions 76b and 78b and the second The wire connection portions 72b and 74b are heated and pressure-welded to electrically and physically connect the wires and the metal terminals.

  The transformer 10 according to the present embodiment has a structure (sandwich structure) in which the middle coil 303 is sandwiched between the upper coil 301 and the lower coil 302. Therefore, the coupling between the coil portions can be increased, and stabilization of leakage characteristics can be facilitated. In addition, it is possible to realize a high coupling transformer 10 capable of obtaining stable leakage characteristics even in a high frequency band.

  In particular, in the transformer 10 according to the present embodiment, the second wire 37 is α-wound around the bobbin 20. The α winding contributes to the reduction in height and size of the transformer 10 because the number of layers in the winding axis direction can be reduced even if the number of turns is increased. Further, since the wire winding from the winding central portion is eliminated by making the winding α, the second wires 37 do not overlap, which contributes to shortening the height of the transformer 10.

  In addition, the middle coil 303 contributes to the stabilization of leakage characteristics by making it α-winding. In addition, it is also easy to make the number of turns of the coil the same between the first and second layers of the middle coil 303, and it is also easy to change the number of turns.

  Further, the upper coil 301 and the lower coil 302 are continuously formed by the first wire 38. With such a configuration, it is possible to prevent the current from flowing unevenly to any one of the upper coil 301 and the lower coil 302. Since the current is prevented from flowing unevenly, any one of the upper coil 301 or the lower coil 302 can be prevented from abnormal heat generation. Further, as compared with the case where the upper coil 301 and the lower coil 302 are configured by separate wires, it is possible to shorten the wire length of the first wire 38 configuring the upper coil 301 and the lower coil 302, and copper loss Can be made smaller. If the copper loss can be reduced, the efficiency can be improved and the heat generation can be reduced.

  Further, in the transformer 10, since the coupling coefficient between the primary coil and the secondary coil is high, stabilization of the leakage characteristics should be achieved even when the number of turns of the primary coil and the number of turns of the secondary coil differ greatly. Is easy. That is, according to the present embodiment, the effect is large even when the turns ratio between the number of turns of the first wire 38 in the upper coil 301 and the lower coil 302 and the number of turns of the second wire 37 in the middle coil 303 is large. Specifically, even when the turns ratio n1 / n2 of the total number of turns n1 of the first wire 38 and the number n2 of turns of the second wire 37 is 2 or more, 3 or more, 5 or more, more remarkable effects can be obtained.

  Further, in the transformer 10, the first wire 38 is α-wound around the bobbin 20. With such a configuration, it is possible to easily form the upper coil 301 and the lower coil 302 which are disposed apart in the winding axial direction by using a single first wire 38. Moreover, it is also easy to make the number of turns of the coil the same between the upper coil 301 and the lower coil 302, and it is also easy to change the number of turns.

  Further, the α winding contributes to reduction in the height and size of the transformer 10 because the number of layers in the winding axis direction can be reduced even if the number of turns is increased. Further, since the wire is not drawn out from the center of the winding by making the α winding, the wires do not overlap, which contributes to reducing the height of the transformer 10.

  The transformer 10 has a sandwich structure of one first wire 38 as shown in FIG. 5 and FIG. 8 by using the first insulating cover 81 shown in FIG. 8, the first wire 38 and the second wire 37. It can implement | achieve with the structure which can be easily manufactured, maintaining insulation. Further, as shown in FIG. 5, the transformer 10 adopts a structure in which the upper coil 301 and the lower coil 302 are connected by the first inter-coil connection portion 380 axially passing the inner diameter side of the middle coil 303. Is advantageous for miniaturization.

  Further, since the bobbin 20 is housed in the case 90 filled with the resin 88, the transformer 10 is excellent in heat dissipation, and the first and second terminal portions 72, 74, 76, 78 are directly attached to the outside. Because the first and second terminal portions 72, 74, 76, and 78 are mounted on another device, the positional variation of the first and second terminal portions 72, 74, 76, and 78 is small.

  For example, in a conventional transformer of a type in which a terminal block is provided on a bobbin, the position of the terminal portion at the time of mounting due to the dimensional error of the bobbin, the mounting error of the bobbin to the case, and distortion due to expansion and contraction of the heat dissipation resin. There is a problem that the accuracy varies. However, in the transformer 10 in which the first and second terminal portions 72, 74, 76, 78 are fixed to the case 90, dimensional error of the bobbin 20, mounting error of the bobbin 20 to the case 90, expansion / contraction of the resin 88 It is possible to reduce or eliminate the influence of distortion and the like on the positional accuracy of the first and second terminal portions 72, 74, 76, 78. Therefore, the transformer 10 is excellent in heat dissipation characteristics, and when mounted on another device, it is possible to accurately arrange the first and second terminal portions 72, 74, 76, 78. Furthermore, in the transformer 10, since the first and second terminal portions 72, 74, 76, 78 are accurately disposed in the mounted state, the wiring operation performed to the external connection portions 72c, 74c, 76c, 78c after mounting is performed. Can be done quickly and easily.

  In the transformer 10, the first and second terminal portions 72, 74, 76, 78 are insert-molded in the case 90. Such a transformer 10 can further improve the positional accuracy of the first and second terminal portions 72, 74, 76, 78, and can be compared to the case where the terminal portions are fixed by adhesion or screwing. It is easy to assemble. Although the attachment positions of the first and second terminal portions 72, 74, 76, 78 are not particularly limited, the first terminal portions 76, 78 to which the first wire 38 is connected are fixed to one side of the case 90, By fixing the second terminal portions 72 and 74 to which the wire 37 is connected to the other side of the case 90, the transformer 10 exhibits good insulation characteristics.

  In addition, the first and second terminal portions 72, 74, 76, 78 are wire connecting portions 72b, 74b, 76b, 78b and the like extending from one side of the terminal fixing portions 72a, 74a, 76a, 78a embedded in the case 90. And external connection parts 72c, 74c, 76c, 78c extending from the other side of the terminal fixing parts 72a, 74a, 76a, 78a. The transformer 10 having such first and second terminal portions 72, 74, 76, 78 is easy to carry out the wiring operation to be performed on the external connection portions 72c, 74c, 76c, 78c after mounting, and the external It is also possible to prevent the problem that the heat at the time of wiring to the connection parts 72c, 74c, 76c and 78c is transmitted to the wire connection parts 72b, 74b, 76b and 78b. As shown in FIGS. 1 and 2, the transformer 10 is disposed such that the external connection portions 72c, 74c, 76c, and 78c project upward, whereby the external connection portions 72c, 74c, 76c, and 76c after mounting are arranged. The wiring work performed for 78c is made easier.

  Further, in the transformer 10, since the ends of the first wire 38 and the second wire 37 are fused to the first and second terminal portions 72, 74, 76, 78, manufacture is easy, In addition, the connection between the first wire 38 and the second wire 37 and the first and second terminal portions 72, 74, 76, 78 is highly reliable. Further, since the wire connection parts 72b, 74b, 76b, 78b formed by fusing can be smaller in size than the connection parts using screws, the transformer 10 is advantageous in terms of reduction in height and miniaturization. In addition, by pulling out the wire connection portions 72 b, 74 b, 76 b, 78 b from the outer periphery of the case 90 in the horizontal direction, the fusing process in the manufacture of the transformer 10 can be efficiently performed.

  The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.

  For example, as another mode of mounting the coil 300 on the outer periphery of the bobbin 20, the second wire 37 is first wound around the bobbin 20 to form the middle coil 303, and then the first wire 38 is wound around the bobbin 20. The aspect which comprises the upper coil 301 and the lower coil 302 is also considered. When the coil 300 is attached to the bobbin 20 in such a manner, the first inter-coil connection portion 380 passes through the outside of the middle coil 303.

  Further, the relationship between the primary coil and the secondary coil described above may be reversed. That is, the first wire 38 may constitute a secondary coil, and the second wire 37 may constitute a primary coil. Moreover, in that case, the magnitude relationship of the outer diameter of each wire may be reverse to the example mentioned above. Alternatively, the outer diameter of these wires may be the same.

DESCRIPTION OF SYMBOLS 10 ... Transformer 20 ... Bobbin 21 ... Bobbin main body 21a ... Through-hole 22 for a core leg 22; 23 ... Wire guide base 221, 231 ... Side wall part 223, 233 ... Separation convex part 224, 234 ... Engagement protrusion part 24, 25 ... End Portion partition wall 26: winding partition wall 26a: first winding partition wall 26b: second winding partition wall 26c: third winding partition wall 261a, 261c: rough surface 264a, 264b, 264c: notch 28: winding Non-overlapping portion 28b: Non-overlapping portion 29: Bobbin leg 300: Coil 301: Upper coil 302: Lower coil 303: Middle coil 37: Second wire 37a, 37b: Second lead portion 370: Second coil Intersections 371a, 371b: Upstanding portions 372a, 372b: Upper wire portions 38: First wires 38a, 38b: First lead portions 381a, 381b Upstanding portion 382a, 382b: Upper wire portion 380: First coil connection portion 40a, 40b ... Magnetic core 44a, 44b ... Base portion 46a, 46b ... Middle leg portion 48a, 48b ... Side leg portion 50 ... Side cover 52 ... Cover Main body 54 Locking piece 56 Side leg guide piece 70 Terminal portion 72, 74 Second terminal portion 76, 78 First terminal portion 72a, 74a, 76a, 78a Terminal fixing portion 72b, 74b, 76b, 78b ... Wire connection portion 72c, 74c, 76c, 78c ... External connection portion 86 ... Base 81 ... First insulating cover 811 ... First portion 鍔 812 ... Second portion 鍔 811a, 812a ... Counterbore 813 ... Middle portion 鍔 814 ... Upper Part part 815 ... Middle part cylinder 816 ... Vertical part 82 ... 2nd insulating cover 821 ... 1st part part 822 ... 2nd part part 823 ... Wall part 88 ... Resin 0 ... Case 98 ... first terminal installation portion 97 ... second terminal installation portion 92 ... bottom plate

Claims (8)

A bobbin wound with a wire;
A case that accommodates the bobbin and is attached to the outside;
A resin filled in a gap between the bobbin and the case;
And a terminal portion fixed to the case and to which the wire is connected.   The coil device according to claim 1, wherein the case and the terminal portion are integrally insert-molded. The wire comprises a first wire and a second wire that is discontinuous with the first wire,
The first wire forms an upper coil and a lower coil which are spaced apart from each other along the winding axis of the bobbin,
The coil device according to claim 1 or 2, wherein the second wire forms a middle coil which is? -Wound between the upper coil and the lower coil. The wire comprises a first wire and a second wire that is discontinuous with the first wire,
The first wire is α-wound around the bobbin so as to form an upper coil and a lower coil which are spaced apart from each other along the winding axis of the bobbin.
The coil device according to any one of claims 1 to 3, wherein the second wire has a middle coil formed between the upper coil and the lower coil.   The terminal portion is provided on the side opposite to the first terminal portion to which the first wire is connected and the side on which the first terminal portion is provided in the case, and the second wire is connected The coil device according to any one of claims 1 to 4, having two terminals.   The terminal portion is a terminal fixing portion which is in contact with and fixed to the case in the terminal portion, a wire connecting portion which extends from the terminal fixing portion to one side and to which the wire is connected, and the other of the terminal fixing portion The coil device according to any one of claims 1 to 5, further comprising: an external connection portion extending to the side.   The coil device according to any one of claims 1 to 6, wherein an end of the wire is fused to the terminal portion. The terminal portion has a wire connection portion to which the wire is connected,
The coil device according to any one of claims 1 to 7, wherein the wire connection portion is disposed outside the outer periphery of the case when viewed from above.

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