JP2016139699A - Coil device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coil device which deals with large electric current of the coil device, enables improvement of heat radiation performance, and inhibits deterioration of magnetic characteristics caused by overheating of the coil part.SOLUTION: A transformer 10 has a magnetic core 40, a bobbin 20, and a coil attached to an outer periphery of the bobbin 20. The magnetic core 40 and a heat sink 80 are connected in a core installation part so as to transmit heat therebetween. The bobbin 20 and the heat sink 80 are connected through a heat transfer resin layer 90 in a bobbin installation part so as to transmit heat therebetween.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a coil device that can be suitably used as a relatively large transformer used for, for example, in-vehicle use and has excellent heat dissipation.

  For example, the following Patent Document 1 is known as a transformer used for charging an EV battery. Thus, a high current is applied to a transformer used in a vehicle or the like, and a countermeasure for heat dissipation is required.

  Conventionally, a heat radiating plate is provided outside the core, and the lower part of the coil device constituting the transformer is covered with a potting resin inside the case to radiate heat from the transformer.

  However, in the case of using a potting resin, it is necessary to prepare a case for injecting the resin and a resin filling operation is required, and various processes are complicated. Therefore, there is an increasing demand for a coil device such as a transformer having excellent heat dissipation characteristics without using a case in which potting resin is accommodated.

  In general transformers, the heat generated by the coil is transmitted to the bobbin, and a heat transfer path from the bobbin to the magnetic core is secured, but for heat transfer from the bobbin to the magnetic core and heat dissipation from the magnetic core to the outside. There is a difficulty, and it is difficult to efficiently release the heat stored inside the coil part (inside the bobbin). If the heat dissipation of the coil device is insufficient, the magnetic characteristics may be deteriorated due to overheating of the coil portion.

JP 2014-36194 A

  The present invention has been made in view of such a situation, and an object thereof is to provide a coil device that can improve heat dissipation and suppress deterioration of magnetic characteristics due to overheating of a coil portion.

In order to achieve the above object, a coil device according to the present invention comprises:
A coil device having a magnetic core, a bobbin, and a coil mounted on the outer periphery of the bobbin,
The magnetic core and the heat radiating member are connected so as to be able to transfer heat at the core installation part,
The bobbin and the heat radiating member are connected so as to be able to transfer heat at a bobbin installation portion.

  Although a heat sink is illustrated as a heat radiating member, heat sinks, such as a heat radiating fin, may be sufficient.

  In the coil device according to the present invention, since the bobbin and the heat radiating member are connected so that heat can be transferred at the bobbin installation part, the heat stored in the bobbin around which the heat generating coil is wound is The heat is dissipated well from the bobbin to the heat radiating member, and heat is dissipated from the heat radiating member.

  In addition, since the magnetic core and the heat radiating member are connected so that heat can be transferred at the core installation portion, the heat stored in the bobbin around which the coil that generates heat is wound is transferred from the bobbin to the magnetic core, The heat is transmitted well from the magnetic core to the heat radiating member, and heat is dissipated from the heat radiating member.

  The heat stored inside the bobbin around which the coil that generates heat is wound is transmitted to the heat radiating member through two paths, and a large amount of heat is diffused by the heat radiating member. Therefore, it is possible to cope with an increase in current of the coil device, heat dissipation is improved, and deterioration of magnetic characteristics due to overheating of the coil portion can be suppressed. Moreover, since the heat dissipation of the coil device is improved, a potting resin for improving the heat dissipation can be eliminated.

  Preferably, in the bobbin installation portion, a heat transfer resin layer is interposed in a gap between the bobbin and the heat dissipation member. The magnetic core and the heat radiating member are designed to be in direct contact with each other, and the bobbin installation portion is designed so that a gap is generated between the bobbin and the heat radiating member. It can be reliably contacted.

  And the heat-transfer path | route from a bobbin to a thermal radiation member is ensured by interposing a heat-transfer resin layer in the clearance gap. As a result, the heat stored in the bobbin around which the heat generating coil is wound is well transmitted to the heat radiating member along two paths, and a large amount of heat is diffused by the heat radiating member.

  Examples of the heat conductive resin layer include heat conductive grease or heat conductive resin. By interposing the heat conductive resin layer between the heat radiating member and the bobbin, there is no air gap, heat transfer performance is improved, and heat radiation performance is improved.

  Preferably, in the bobbin installation part, a block having better heat transfer characteristics than the bobbin is installed between the bobbin and the heat radiating member. A block can be comprised, for example with metals, such as aluminum, the heat conductivity between a bobbin and a thermal radiation member further improves, and the thermal radiation characteristic as a whole also improves.

  The bobbin installation part may be formed with a recess for accommodating the block, and the block may be formed integrally with the heat dissipation member.

  Preferably, the magnetic core is divided into an upper core and a lower core. By comprising in this way, it becomes easy to assemble a coil apparatus. In addition, it is preferable that the upper core and the lower core are also configured by divided cores. In that case, heat dissipation can be further improved by forming a gap between the split cores.

FIG. 1 is a partial perspective view of a transformer as a coil device according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the transformer shown in FIG. 3 is a cross-sectional view of the transformer along the line III-III shown in FIG. 4A is a cross-sectional view of the transformer taken along line IV-IV shown in FIG. 4B is a cross-sectional perspective view of the transformer along the line IV-IV shown in FIG. FIG. 4C is a cross-sectional view of a transformer according to another embodiment of the present invention, corresponding to FIG. 4A. 4D is a cross-sectional view of a transformer according to still another embodiment of the present invention, and is a cross-sectional view corresponding to FIG. 4A. FIG. 4E is a cross-sectional view of a transformer according to still another embodiment of the present invention, and is a cross-sectional view corresponding to FIG. 4A. 5A is a cross-sectional perspective view of the transformer along the line VA-VA shown in FIG. 4A. 5B is a cross-sectional perspective view of the transformer along the line VB-VB shown in FIG. 4A. FIG. 6 is a perspective view of a transformer according to another embodiment of the present invention. 7 is an exploded perspective view of the transformer shown in FIG. 8 is a cross-sectional view of the transformer along the line VIII-VIII shown in FIG.

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

First Embodiment As shown in FIGS. 1 and 2, a transformer 10 as a coil device according to the present embodiment is used, for example, as a transformer such as a reactor, for example, for battery charging of an EV. The transformer 10 includes a bobbin 20, a magnetic core 40, and heat dissipation covers 70a and 70b, and is attached to the upper surface of the housing 60. The casing 60 is, for example, a plate-like member to which the transformer 10 is attached, and may be one of automobile parts. Even if cooling water flows on the back surface (the side opposite to the attachment surface of the transformer 10). good.

  As shown in FIG. 2, the bobbin 20 includes a bobbin main body 24 and terminal block portions 22 and 23 that are integrally formed on both upper ends of the bobbin main body 24 in the X-axis direction. The terminal block portions 22 and 23 are respectively formed with lead attachment portions 22a, 22b and 23a, 23b at both ends in the Y-axis direction. A lead portion (not shown) of the second wire is connected.

  As shown in FIG. 2, in the present embodiment, the magnetic core 40 includes an upper core 40a and a lower core 40b. These cores 40a and 40b can be separated into two divided cores 42a and 42a and 42b and 42b having the same shape. In the present embodiment, each of the divided cores 42a, 42a and 42b, 42b has the same shape, has a U-shaped cross section in the ZY section, and is a kind of U-shaped core.

  By combining a pair of split cores 42a and 42a arranged at the upper part in the Z-axis direction, the Z-Y cross section has an E-shaped cross section, and constitutes a so-called E-type core. The other pair of split cores 42b and 42b arranged at the lower part in the Z-axis direction are combined to form a so-called E-type core having an E-shaped cross section in the ZY cross section.

  Each split core 42a arranged on the upper side in the Z-axis direction includes a base portion 44a extending in the Y-axis direction, and a pair of middle leg portions 46a and sides projecting in the Z-axis direction from both ends in the Y-axis direction of the base portion 44a. Legs 48a. Each split core 42b disposed on the lower side in the Z-axis direction includes a base portion 44b extending in the Y-axis direction, a pair of middle leg portions 46b protruding in the Z-axis direction from both ends of the base portion 44b in the Y-axis direction, and Side legs 48b.

  As shown in FIG. 2, the pair of middle leg portions 46 a are inserted into the core leg through hole 26 of the bobbin 20 from above in the Z-axis direction. Similarly, the pair of middle leg portions 46b are inserted into the core leg through hole 26 of the bobbin 20 from below in the Z-axis direction, and in the through hole 26, their tips are the tips of the middle leg portion 46a. And face each other with a predetermined gap.

  Inside the through hole 26, a separation plate portion 27 (see FIG. 2) or a convex portion extends along the Z axis direction along the X axis direction so that the through hole 26 is divided in the Y axis direction at the center. It may be formed. The separation plate portion 27 (the same applies to the convex portion) is interposed between the pair of middle leg portions 42a and 42a, and is interposed between the middle leg portions 42b and 42b, and these middle leg portions 42a and 42a or The middle leg portions 42b and 42b are configured to face each other at a predetermined gap inside the through hole 26 and do not come into contact with each other. The predetermined gap can be adjusted by the thickness of the separating plate portion 27 in the Y-axis direction.

  The middle leg portions 42a and 42a or the middle leg portions 42b and 42b have an elliptical column shape that is long in the X-axis direction so as to match the inner peripheral surface shape of the through hole 26 in a combined state. The shape is not particularly limited, and may be changed according to the shape of the through hole 26. The side legs 48a and 48b have an inner concave curved surface shape that matches the shape of the outer peripheral surface of the bobbin main body 24, and the outer surface has a plane parallel to the XZ plane. In the present embodiment, the material of each of the split cores 42a and 42b may be a soft magnetic material such as metal or ferrite, but is not particularly limited.

  In the drawing, the X axis, the Y axis, and the Z axis are perpendicular to each other, and the Z axis coincides with the winding axis of the first wire 37 and the second wire 38 described later, and the height (thickness) of the transformer 10. ). In the present embodiment, the lower side of the transformer 10 in the Z-axis direction is the installation surface of the transformer (the surface of the housing 60). Further, the Y axis coincides with the direction in which the pair of split cores 42a and 42a or the pair of split cores 42b and 42b are split. Further, the X axis is adapted to coincide with the longitudinal direction of the middle legs 46a, 46b.

  As shown in FIG. 3, at both ends in the Z-axis direction of the winding tube portion 28 of the bobbin 20 in the transformer 10 of the present embodiment, the end partition walls 31 and 32 extend radially outward. -It is integrally molded substantially parallel to the Y plane. Predetermined in the Z-axis direction so that the winding partition walls 33 to 36 protrude radially outward on the outer peripheral surface of the winding tube portion 28 located between the end partition walls 31 and 32 in the Z-axis direction. It is formed at intervals.

  Due to the winding partition walls 33 to 36 formed between the end partition walls 31 and 32, winding sections S1 to S5 are formed between these partition walls in order from the bottom in the Z-axis direction. The In addition, the number of winding partition wall 33-36 and winding division S1-S5 is not specifically limited.

  In the present embodiment, the first wire 37 is continuously wound around the winding sections S1 and S2, and the second wire 38 is continuously wound around the sections S3 to S5. In the present embodiment, the first wire 37 constitutes a primary coil and the second wire 38 constitutes a secondary coil, but the reverse may be possible.

  In the present embodiment, as shown in FIGS. 5A and 5B, the wound partition wall 33 is formed with at least one communication groove 33a that connects the adjacent sections S1 and S2. As shown in FIG. 5B, the first wire 37 wound around the section S1 is passed through the section S2 through the communication groove 33a, and can be wound around the outer periphery of the winding tube portion 28 of the bobbin 20 in this section S2. ing.

  Further, as shown in FIG. 5A, the wound partition wall 36 is formed with at least one communication groove 36a that connects the adjacent sections S4 and S5 to each other. The second wire 38 wound around the section S4 is passed through the section S5 through the communication groove 36a, and can be wound around the outer periphery of the winding tube portion 28 of the bobbin 20 in the section S5.

  Although not shown in the drawings, the winding partition wall 35 also has a communication groove similar to the communication groove 36a. Further, with respect to the winding rod 34, in order to insulate the first wire 37 and the second wire 38, it is not necessary to form a communication groove similar to these. In the present embodiment, the communication groove 32a for the first wire 37 and the communication groove 36a for the second wire 38 are preferably formed on opposite sides in the X-axis direction.

  As shown in FIG. 3, the section width T1 along the Z-axis in each section S1, S2 around which the first wire 37 is wound is set to a width that allows only one first wire 37 to enter in the Z-axis direction. It is. However, the partition width T1 may be set to a width in which two or more first wires 37 can enter. In the present embodiment, the partition widths T1 are preferably all the same, but may be slightly different.

  Further, the section width T2 along the Z axis in each of the sections S3 to S5 around which the second wire 38 is wound is set to a width in which only one second wire 38 can enter in the Z axis direction. The wire winding portions can be separated from each other for each section. In the present embodiment, the section width T2 along the Z axis in each of the sections S3 to S5 may be the same as or different from the section width T1 according to the wire diameter of the second wire 38.

  Moreover, the height (length in the radial direction with respect to the winding axis) H1 of the partition rods 31 to 36 is set to a height at which one (one or more layers) of wires 37 or 38 can enter. In the form, it is preferably set to a height at which 2 to 8 layers of wire can be wound. The heights H1 of the partition walls 31 to 36 are preferably all the same, but may be different. In the present embodiment, the winding method of the wire 37 or 38 wound around each of the sections S1 to S5 is not particularly limited, and normal winding or α winding may be used.

  The wires 37 and 38 may be composed of single wires or may be composed of stranded wires, and are preferably composed of insulation-coated conductive wires. The outer diameters of the wires 37 and 38 are not particularly limited, but when a large current is passed, for example, φ1.0 to φ3.0 mm is preferable. The second wire 38 may be the same as the first wire 37, but may be different.

  As shown in FIGS. 4A and 4B, bobbin leg portions 31a are integrally formed at both ends in the X-axis direction of the end partition ribs 31 located at the lowest part in the Z-axis direction. Each bobbin leg portion 31a is formed to protrude downward from the both ends in the X-axis direction of the end partition wall 31 in the Z-axis direction, and between the bottom surface of the leg portion 31a and the heat radiating plate 80, a heat transfer resin. It is preferable to form a gap for forming the layer 90.

  That is, as shown in FIG. 4A, it is preferable that the height T3 of the leg portion 31a in the Z-axis direction is designed to be shorter than the thickness T4 of the base portion 44b of the lower core 40b. (T4-T3) corresponds to the thickness T5 of the heat conductive resin layer 90. The thickness T5 of the heat transfer resin layer 90 is preferably as small as possible, but a certain amount of thickness is necessary to absorb manufacturing errors.

  By ensuring the thickness T5 of the heat transfer resin layer 90, the adhesion between the magnetic core 40 and the bobbin 20 is ensured even if there is a manufacturing error of each of the split cores 40a and 40b of the magnetic core 40 or a bobbin manufacturing error. The heat transfer characteristics are improved. In addition, the bottom surface 41 of the magnetic core 40 can directly contact the surface 2 of the heat sink 80 at the core installation portion 82 of the heat sink 80.

  In addition, as the heat conductive resin layer 90, heat conductive grease or heat conductive resin is illustrated, for example. By interposing the heat conductive resin layer 90 between the heat radiating plate 80 and the bobbin 40, there is no air gap, heat transfer performance is improved, and heat dissipation performance is improved. The heat conductive resin layer 90 can also function as an adhesive between the bobbin 20 and the heat sink 80. A resin layer similar to the heat transfer resin layer 90 is interposed between the inner peripheral surface of the core leg through hole 26 of the bobbin 20 and the outer peripheral surfaces of the middle leg portions 46a and 46b of the magnetic core 40 shown in FIG. Also good.

  The bobbin 20 is made of plastic such as PPS, PET, PBT, LCP, and nylon, but may be made of other insulating members. However, in this embodiment, the bobbin 20 is preferably made of a plastic having a high thermal conductivity of, for example, 1 W / m · K or more, and is made of, for example, PPS or nylon.

  As shown in FIGS. 1 and 2, a pair of heat radiation covers 70 a and 70 b are disposed so as to cover the upper surface in the Z-axis direction and the side surface in the Y-axis direction of the magnetic core 40 after assembly. Each of the heat radiation covers 70a and 70b has an L shape in the ZY cross section, and includes upper surface cover portions 72a and 72b and side surface cover portions 74a and 74b.

  As shown in FIG. 3, the upper surface cover portions 72a and 72b cover the upper surfaces of the split cores 42a and 42a, respectively. The Y-axis direction front end portions 72a1 and 72b1 of the upper surface cover portions 72a and 72b face each other, but are preferably designed so as not to contact each other.

  If they are designed to come into contact with each other, due to manufacturing errors in the dimensions of the magnetic core 40, the side cover portions 74a and 74b and the side surface (the side surface perpendicular to the Y axis) in the Y-axis direction of the magnetic core 40 are formed. This is because there may be a gap between them. If there is a gap, heat transfer characteristics from the magnetic core 40 to the heat radiation covers 70a and 70b may be deteriorated. Therefore, it is preferable that the side covers 74a and 74b are in close contact with the Y axis direction opposite side surface of the magnetic core 40.

  Of course, the upper surface covers 72 a and 72 b are also preferably in close contact with the upper surface of the magnetic core 40. An adhesive may be used to bring the heat radiation covers 70a and 70b into close contact with the magnetic core.

  The height H2 in the Z-axis direction of the side covers 74a and 74b is preferably designed to be shorter than the height H3 in the Z-axis direction of the combined magnetic core 40. If the height H2 is designed to be equal to or higher than the height H3, the lower ends of the side covers 74a and 74b collide with the upper surface of the housing 60 or the upper surface of the heat sink 80 depending on the manufacturing error of the magnetic core 40. There is a risk. As a result, the adhesion between the upper surface covers 72a and 72b and the upper surface of the magnetic core 40 may be impaired.

  The heat radiation covers 70a and 70b can be formed integrally by bending or pressing a single plate material, for example. Alternatively, a plurality of plate materials may be joined by laser welding or the like. The heat radiation covers 70a and 70b are made of a material having better heat transfer characteristics than the magnetic core 40 and the bobbin 20, and are made of a metal plate such as aluminum, copper, stainless steel, brass, or iron. Although the thickness of a metal plate is not specifically limited, For example, it is 0.2-1.5 mm, Preferably it is 0.3 mm-0.7 mm.

  In this embodiment, as shown in FIG. 4A, the bobbin 20 and the heat radiating plate 80 are connected so that heat can be transferred through the heat conductive resin layer 90 at the bobbin installation portions 83 located at both ends of the heat radiating plate 80 in the X-axis direction. doing. For this reason, the heat stored in the bobbin 20 around which the coiled first wire 37 or the second wire 38 that generates heat is wound is well transmitted from the bobbin 20 to the heat radiating plate 80 by the bobbin installation portion 83. Heat is dissipated from the radiator plate 80 through the housing 60.

  The heat radiating plate 80 may be provided with a heat sink such as a heat radiating fin. In the present embodiment, the heat radiating plate 80 is made of, for example, the same metal as the heat radiating covers 70 a and 70 b and is fixed to the surface of the housing 60. When the case 60 is made of a member having high thermal conductivity such as metal, the heat trapped inside the center of the bobbin 20 is efficiently passed to the case 60 through the heat conductive resin layer 90 and the heat radiating plate 80. Can be missed.

  Further, the magnetic core 40 and the heat radiating plate 80 are connected by the core installation portion 82 so that heat can be transferred. For this reason, the heat stored in the bobbin 20 around which the coiled first wire 37 or the second wire 38 that generates heat is wound is transmitted from the bobbin 20 to the magnetic core 40, and from the magnetic core 40 to the heat radiating plate 80. The heat is dissipated well and the heat is dissipated from the radiator plate 80 through the housing 60.

  The heat stored in the bobbin 20 around which the coiled first wire 37 or the second wire 38 that generates heat is wound is transferred to the heat radiating plate 80 and the housing 60 through two paths, A lot of heat is dissipated. Therefore, it is possible to cope with an increase in current of the transformer 10, heat dissipation is improved, and deterioration of magnetic characteristics due to overheating of the coil portion can be suppressed. Moreover, since the heat dissipation of the transformer 10 is improved, a potting resin for improving the heat dissipation can be eliminated.

  Furthermore, in the transformer 10 according to the present embodiment, the winding partition walls 33 to 36 for separating the wire winding portions adjacent to each other along the winding axis (Z axis) of the wire 37 (38) are formed. Therefore, even if the outer diameter of the wire 37 (38) is increased, insulation is easy, and it is easy to cope with a large current (high output). Conventionally, with the increase in the frequency of the voltage, there is an adverse effect that adjacent wires influence each other and current does not easily flow. However, in the transformer 10 of the present embodiment, the winding partition walls 33 to 36 are provided. Therefore, such adverse effects can be reduced, and high frequency characteristics are improved. Furthermore, since the end partition walls 31 and 32 and the winding partition walls 33 to 36 also function as heat dissipation fins, the heat dissipation of the transformer 10 is also excellent.

  Furthermore, in this embodiment, in order to wind the wire 37 (38) so that only a single wire exists along the winding axis direction in each of the sections S1 to S5, the wire 37 (38) per layer is used. This makes it easy to prevent variations in the number of windings, and contributes to stabilization of coil characteristics. That is, the coupling coefficient K between the primary coil and the secondary coil can be strictly controlled.

  Furthermore, in this embodiment, the split leg portions 46a and 46b of the split cores 42a and 42b that are split into a U-shaped cross section are inserted into the core leg through hole 26 of the bobbin 20. According to experiments by the present inventors, even if the core becomes large by such a configuration, compared with the case where a conventional E-type core is used, at the intersection of the middle leg and the base The generated local stress can be dispersed. Therefore, in the transformer 10 according to the present embodiment, it is possible to effectively suppress the occurrence of cracks or the like even when thermal stress occurs in the core.

  Further, the middle legs 46a, 46b and the base in the E-type core configured by combining the split cores 42a, 42b are separated by the split surfaces of the split cores 42a, 42b, and a predetermined interval is provided between the split surfaces. A gap can be formed, and heat dissipation is improved. Furthermore, the E-type core is configured by combining a pair of split cores 42a and 42b each having a simple shape, which facilitates the manufacture of the core and reduces the manufacturing cost. Moreover, since the split E-type core as a whole has the same magnetic field lines as the E-type core, the magnetic properties of the core are equivalent to those of a general E-type core.

Second Embodiment As shown in FIG. 4C, the transformer 10a of this embodiment has the same configuration as that of the first embodiment except for the configuration described below, and has the same effects. Hereinafter, the description of the overlapping part is omitted.

  In the transformer 10a of the present embodiment, a recess 31b is formed on the bottom surface of the bobbin leg 31a, and the heat conductive block 100 is mounted in the recess 31b. The heat-rollable block is made of, for example, the same metal as the heat sink 80 or a different metal. The heat conductive block 100 may be fixed inside the recess 31b with an adhesive 90a or the like. The adhesive 90a is preferably the same as the resin constituting the heat conductive resin layer 90, for example, but is not necessarily the same. The bottom surface of the block 100 is preferably flush with the bottom surface of the leg portion 31a.

  In the bobbin installation part 83, since the block 100 having better heat transfer characteristics than the bobbin 20 is installed between the bobbin 20 and the heat sink 80, the heat transfer between the bobbin 20 and the heat sink 80 is improved. This further improves the overall heat dissipation characteristics.

  The shape of the recess 31b formed at the bottom of the bobbin leg 31a is not particularly limited. For example, as shown in FIG. 4D, the recess 31b opens toward the end in the X-axis direction and the bottom in the Z-axis direction. There may be. The shape of the block 100 may be changed in accordance with the shape of the recess 31b.

  Furthermore, as shown in FIG. 4E, in the bobbin installation portion 83 of the heat radiating plate 80, the heat conductive block 100a may be joined to the heat radiating plate 80 by means such as welding, or may be integrally formed. May be.

Third Embodiment As shown in FIGS. 6 to 8, the transformer 10b of this embodiment has the same configuration as that of the first embodiment and the second embodiment except for the configuration described below, and has the same function and effect. Play. Hereinafter, the description of the overlapping part is omitted.

  In the transformer 10b of the present embodiment, a recess 31b is formed on the bottom surface of the bobbin leg 31a, and the heat conductive block 100 is attached to the recess 31b. The heat-rollable block is made of, for example, the same metal as the heat sink 80 or a different metal. The heat conductive block 100 may be fixed inside the recess 31b with an adhesive 90a or the like. The adhesive 90a is preferably the same as the resin constituting the heat conductive resin layer 90, for example, but is not necessarily the same. The bottom surface of the block 100 is preferably flush with the bottom surface of the leg portion 31a.

  In the present embodiment, rising pieces 80c are integrally formed with the heat radiating plate 80b at both ends in the X-axis direction of the heat radiating plate 80b. The rising piece 80c has a fitting hole that covers the lower side surface of the bobbin leg portion 31a and fits into the fitting convex portion 31c formed on the outer peripheral surface of the bobbin leg portion 31a.

  In the present embodiment, as illustrated in FIG. 7, the transformer 10 b of the present embodiment does not include the heat dissipation covers 70 a and 70 b illustrated in FIG. 2, but includes a pair of covers 50. The cover main body 52 of the cover 50 has a shape that covers the outer periphery of the bobbin main body 24 located between the terminal blocks 22 and 23 in the bobbin 20b. At both ends in the Z-axis direction of the cover body 52, locking pieces 54 bent in a substantially vertical direction from the cover body 52 toward the bobbin body 24 are integrally formed. A pair of locking pieces 54 formed on both sides in the Z-axis direction of the cover body 52 are attached so as to sandwich the upper and lower surfaces of the bobbin body 24 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 in the X-axis direction of the cover body 52. The outer surface of the cover main body 52 located between the pair of side leg guide pieces 56 is in contact with the inner surfaces of the side legs 48a and 48b, and the movement of the side legs 48a and 48b in the X-axis direction causes the pair of side legs 48a and 48b to move. The guide piece 56 is limited. These covers 50 are made of an insulating member such as plastic similar to the bobbin 20b.

  Furthermore, the transformer 10b of this embodiment includes a lead insulating cover 110. The insulating cover 110 includes a second wire 38 wound around the lead portions 37a and 37a and the bobbin 20b in the middle of the lead portions 37a and 37a of the first wire from the lower side in the Z-axis direction toward the upper side in the terminal block 22 direction. It may be used to ensure sufficient insulation.

  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, in the transformers 10, 10a, and 10b of the present embodiment, the manner of dividing the magnetic core may be changed. For example, in the above-described embodiment, the magnetic core is configured by the combination of the U core and the U core that are the split cores. However, the magnetic core may be assembled by the combination of the U core and the I core. Further, the shape and structure of the bobbins 20 and 20b, the number of windings and the winding method of the wires 37 and 38 are not limited to the illustrated embodiment, and various modifications may be made.

10, 10a, 10b ... Transformers 20, 20b ... Bobbins 22, 23 ... Terminal block portions 22a, 22b, 23a, 23b ... Lead mounting portions 24 ... Bobbin body 26 ... Core leg through holes 28 ... Winding tube portions 31, 32 End partition wall 33-36 Winding partition wall 37 ... First wire 38 ... Second wire 40 ... Magnetic core 40a ... Upper core 40b ... Lower core 42a, 42b ... Split cores 44a, 44b ... Base parts 46a, 46b ... middle legs 48a, 48b ... side legs 50 ... cover 60 ... housings 70a, 70b ... heat dissipation cover 80 ... heat dissipation plate 90 ... heat transfer resin layer

Claims (5)

A coil device having a magnetic core, a bobbin, and a coil mounted on the outer periphery of the bobbin,
The magnetic core and the heat radiating member are connected so as to be able to transfer heat at the core installation part,
The coil device, wherein the bobbin and the heat radiating member are connected so as to be able to transfer heat at a bobbin installation portion.   2. The coil device according to claim 1, wherein a heat transfer resin layer is interposed in a gap between the bobbin and the heat radiating member in the bobbin installation portion.   3. The coil device according to claim 1, wherein a block having a heat transfer characteristic superior to that of the bobbin is installed between the bobbin and the heat dissipation member in the bobbin installation unit.   The coil device according to claim 3, wherein the bobbin installation portion has a recess for receiving the block.   The coil device according to claim 3 or 4, wherein the block is formed integrally with the heat dissipation member.

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