JP6443635B2 - Transformer and transformer manufacturing method - Google Patents

Description

  The present invention relates to a transformer that secures heat dissipation performance and a method of manufacturing the transformer.

  The transformer is used as a main part of an insulation type DC-DC converter that is a DC voltage conversion circuit, and the voltage input to the primary winding side according to the turns ratio of the primary winding and the secondary winding, It has a function of converting to a voltage of another value on the secondary winding side.

  FIG. 5 shows a conventional transformer described in Patent Document 1. In FIG. 5, the conventional transformer 10 includes a pair of magnetic cores 14, an inner bobbin 11, an outer bobbin 12, a cover 13, a case 17, and a heat radiating resin 18. The case 17 is manufactured by winding the inner winding 15 around the inner bobbin 11 and winding the outer winding 16 around the outer bobbin 12 so that the upper part of the transformer 10 is exposed as shown in FIG. Housed inside. The case 17 is filled with a heat radiation resin 18. The pair of upper and lower magnetic cores 14 are assembled to form a magnetic path through which the magnetic flux generated by the windings 15 and 16 passes. The magnetic core 14 has a symmetrical shape and is connected to each other so as to sandwich the inner bobbin 11 and the outer bobbin 12 from above and below.

JP 2014-93404 A

  However, by placing the transformer 10 in the case 17 and filling with the heat radiating resin 18, the heat generated in the windings 15 and 16 is radiated to the lower heat sink (not shown in FIG. 5) via the heat radiating resin 18. Since heat dissipation performance is secured, a large amount of heat dissipation resin is required, the transformer 10 is heavy, and the price is increased.

  The present invention solves the above-described conventional problems, and aims to provide a lightweight and low-cost transformer that secures heat radiation performance without filling a certain height from the bottom surface with heat radiation resin, and a method of manufacturing the transformer. To do.

In order to achieve the above object, a transformer according to one aspect of the present invention includes:
An inner winding wound around an inner bobbin, an outer bobbin wrapped around the inner winding, an outer winding wound around the outer bobbin, and a cover wrapped around the outer winding. A coil unit formed with
A magnetic core unit in which a magnetic core is inserted from above and below the inner bobbin and the outer bobbin of the coil unit, and a magnetic path is formed in a direction perpendicular to a winding direction of the inner winding and the outer winding; and
At least a gap between the inner bobbin and the inner winding inside the region where the magnetic path of the magnetic core is formed, and the inner bobbin outside the region where the magnetic path of the magnetic core is formed And the gap between the outer winding and the cover outside the region where the magnetic path of the magnetic core is formed are filled with heat radiation resin to dissipate heat. Forming the resin part,
And the gap between the magnetic cores wherein the magnetic path and the inner winding of the inner region being formed the outer bobbin, and inside the outer bobbin of the region where the magnetic path of the magnetic core is formed A space in which a heat radiation resin is not filled in each of the gap between the outer windings and the gap between the outer winding and the cover inside the region where the magnetic path of the magnetic core is formed. Part.

Moreover, the method of manufacturing a transformer according to another aspect of the present invention includes a step of winding an inner winding around the inner bobbin after applying a heat radiation resin to a winding portion of the inner bobbin;
Winding the outer winding around the outer bobbin;
Inserting the outer bobbin into the inner bobbin,
After the three steps, heat dissipation resin is applied to at least one of the outside of the outer winding or the inside of the cover, which is outside the region where the magnetic path of the magnetic core is formed ,
A coil unit is formed by fitting the cover to the outer bobbin fitted to the inner bobbin,
Inserting the magnetic core from above and below the inner bobbin and the outer bobbin of the coil unit, forming a magnetic path in a direction perpendicular to the winding direction of the inner winding and the outer winding,
At least a gap between the inner bobbin and the inner winding inside the region where the magnetic path of the magnetic core is formed, and the inner bobbin outside the region where the magnetic path of the magnetic core is formed Radiating heat with a heat-dissipating resin applied to each of the gap between the inner winding and the gap between the outer winding and the cover outside the region where the magnetic path of the magnetic core is formed. A resin portion is formed.

  By this transformer and the method of manufacturing the transformer, it is possible to realize a light-weight and low-cost transformer that ensures heat dissipation performance without filling a certain height from the bottom surface with heat dissipation resin.

  As described above, according to the transformer and the method of manufacturing a transformer according to the aspect of the present invention, since it is not necessary to fill with a heat radiation resin from the bottom surface to a certain height (for example, a height higher than the winding portion), It is possible to provide a light-weight and low-cost transformer that ensures performance.

The perspective view of the trans | transformer in 1st Embodiment of this invention 1 is an exploded perspective view of the transformer shown in FIG. 1 is a cross-sectional end view of the transformer taken along line 3A-3A shown in FIG. 1 according to the first embodiment of the present invention. Cutaway end view of the cross section taken along line 3B-3B of the transformer shown in FIG. 1 according to the first embodiment of the present invention. Sectional drawing which follows the 3C-3C line | wire of the transformer | transformer shown in FIG. 1 in 1st Embodiment of this invention. Cutting section end view in a section along line 4A-4A of the transformer shown in FIG. 1 in the second embodiment of the present invention. Cut section end view in a section along 4B-4B of the transformer shown in FIG. 1 in the second embodiment of the present invention. Sectional drawing which follows the 4C-4C line | wire of the transformer shown in FIG. 1 in 2nd Embodiment of this invention. Sectional drawing which shows the conventional transformer described in patent document 1

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the transformer 100 according to the first embodiment of the present invention includes an inner bobbin 101, an outer bobbin 102, a pair of covers 103, and a total of four magnetic cores 104 in a pair of upper, lower, left, and right. Have.

  Furthermore, as shown in FIG. 2, the inner bobbin 101 includes an inner bobbin winding portion 101a, upper and lower inner bobbin flange portions 101b, and an inner bobbin hollow cylindrical portion 101c, and each portion is formed by injection molding or the like. Manufactured by integral molding. The inner bobbin winding part 101a is disposed on the outer periphery of the inner bobbin hollow cylinder part 101c. The upper and lower inner bobbin flange portions 101b are respectively disposed at the upper end and the lower end of the inner bobbin hollow cylinder portion 101c and project outward in the radial direction. On the lower surface of the lower inner bobbin flange 101b, lower end contact portions 101e that can come into contact with the heat sink 108 are disposed at both ends in the longitudinal direction. A through hole 101p is formed inside the inner bobbin hollow cylinder portion 101c.

  The outer bobbin 102 includes an outer bobbin winding part 102a, upper and lower outer bobbin flange parts 102b, and an outer bobbin hollow cylinder part 102c, and each part is manufactured by integral molding by injection molding or the like. The outer bobbin winding part 102a is disposed on the outer periphery of the outer bobbin hollow cylinder part 102c. The upper and lower outer bobbin flanges 102b are respectively arranged at the upper end and the lower end of the outer bobbin hollow cylinder portion 102c and project outward in the radial direction. A through hole 102p is formed inside the outer bobbin hollow cylinder portion 102c.

  By inserting the inner bobbin 101 into the inner through-hole 102p of the outer bobbin hollow cylindrical portion 102c, the outer bobbin 102 is disposed on the radially outer side of the inner bobbin 101, and a pair of covers 103 are disposed on the radially outer side of the outer bobbin 102. Be placed. In addition, the lower end contact part 103e which can contact the heat sink 108 is arrange | positioned in the lower surface of each cover 103 at the edge part.

  As described above, the inner winding 105 wound around the inner bobbin 101, the outer bobbin 102 that wraps around the inner winding 105, the outer winding 106 wound around the outer bobbin 102, and the outer winding. A coil unit 120 is formed by a cover 103 that wraps around the cover 106.

  3A shows an end view of a cut portion in a cross section taken along the line 3A-3A of the transformer 100 of FIG. A pair of covers 103 are attached to the outer periphery of the outer bobbin winding portion 102 a of the outer bobbin 102 around which the outer winding 106 is wound from both sides in the longitudinal direction of the transformer 100. The inner bobbin 101, the outer bobbin 102, and the cover 103 are each made of an insulating synthetic resin, and insulate and separate the magnetic core 104, the inner winding 105, and the outer winding 106. Further, the inner winding 105 is wound around the outer periphery of the inner bobbin winding portion 101a, and the outer winding 106 is wound around the outer periphery of the outer bobbin winding portion 102a. The outer bobbin 102 can be fitted from above.

  Further, the legs 104a of the magnetic core 104 enter the through holes 101p of the inner bobbin hollow cylinder part 101c and the through holes 102p of the outer bobbin hollow cylinder part 102c from the vertical direction, respectively, and the legs 104a are abutted at the center part. It is like that. A pair of magnetic cores 104 in the vertical and horizontal directions form a magnetic path through which magnetic flux generated by the inner winding 105 and the outer winding 106 passes. As described above, the magnetic core 104 is inserted from the upper and lower sides of the inner bobbin 101 and the outer bobbin 102 of the coil unit 120, and a magnetic path is formed in a direction perpendicular to the winding direction of the inner winding 105 and the outer winding 106. The unit 121 is configured.

  By fitting the outer bobbin 102 wound with the outer winding 106 from above the inner bobbin 101 wound with the inner winding 105, the inner winding 105 and the outer winding 106 are coupled. The winding 105 and the outer winding 106 only need to be coupled, and the method for fitting the inner bobbin 101 and the outer bobbin 102 is not limited to this. Further, by attaching a pair of covers 103 from both sides of the outer bobbin 102 around which the outer winding 106 is wound, the outer winding 106 and the magnetic core 104 are insulated and separated. As long as it can be insulated from 104, the method of fitting the cover 103 is not limited to this.

  Further, each of the inner winding 105 and the outer winding 106 may be composed of a single wire, or may be composed of a stranded wire, and is preferably composed of an insulation-coated conductive wire. . The outer winding 106 may have the same outer diameter as the inner winding 105, but may be different.

  The magnetic core 104 has a shape obtained by dividing the E-type core. However, any magnetic core 104 may be used as long as it can form a closed magnetic circuit with respect to the winding, and any U-type, I-type, or PQ-type can be used. A magnetic core having a shape may be used. The material may be a soft magnetic material such as metal in addition to ferrite.

  The transformer 100 according to the first embodiment of the present invention will be described below with reference to FIGS. 3A, 3B, and 3C. 3A is a cross-sectional end view taken along the line 3A-3A in FIG. 1, FIG. 3B is a cross-sectional end view taken along the line 3B-3B in FIG. 1, and FIG. 3C is a cross-sectional view taken along the line 3C-3C in FIG. is there. As shown in FIG. 3A, the transformer 100 according to the first embodiment of the present invention is provided with a plate-like heat sink 108 below, and the heat generated by the transformer 100 is dissipated to the heat sink 108.

As shown in FIG. 3C, in the transformer 100 according to the first embodiment of the present invention, the gap between the inner bobbin 101 and the inner winding 105 inside the region where the magnetic path of the magnetic core 104 is formed (inside the magnetic path ). 181, the gap 182 between the inner bobbin 101 and the inner winding 105 outside the region where the magnetic path of the magnetic core 104 is formed (outside the magnetic path ) , and the region where the magnetic path of the magnetic core 104 is formed Heat dissipation resin portions 107 are formed by filling the outer space (outside the magnetic path ) outer winding 106 and the gap 188 between the covers 103 with heat dissipation resin, respectively. On the other hand, the gap 183 between the inner winding 105 and the outer bobbin 102 inside (in the magnetic path ) of the area where the magnetic path of the magnetic core 104 is formed, and the inside of the area where the magnetic path of the magnetic core 104 is formed the void 185 between the outer bobbin 102 and the outer winding 106 (the magnetic path), the gap between the outer winding 106- cover 103 of the inner region the magnetic path of the magnetic core 104 is formed (the magnetic path) In 187, a space portion 109 is formed which is left without being filled with a heat radiating resin. Thermal conduction is performed in the heat radiation resin portion 107 of the gap 181, the gap 182, and the gap 188, while heat conduction is not performed in the space portion 109 of the gap 183, the gap 185, and the gap 187. For this reason, as will be described in detail later, the heat generated by the inner winding 105 and the outer winding 106 of the transformer 100 is radiated to the heat sink 108 via the inner bobbin 101, the outer bobbin 102, and the heat radiating resin portion 107. The temperature of each part of the transformer can be set to a specified value or less. In the magnetic path forming region 180 of FIG. 3C, it is shown that the heat radiating resin portion 107 in which the gap 181 between the inner bobbin 101 and the inner winding 105 is filled with the heat radiating resin is formed. Except for the magnetic path forming region 180 in FIG. 3C, the gap 182 between the inner bobbin 101 and the inner winding 105 and the gap 188 between the outer winding 106 and the cover 103 are filled with the heat radiating resin to form the heat radiating resin portion 107. It shows that.

  A gap 181 between the inner bobbin 101 and the inner winding 105 and a gap 188 between the outer winding 106 and the cover 103 are main paths for heat dissipation of the inner winding 105 and the outer winding 106 (the heat dissipation path will be described later). Therefore, it is desirable that almost all or 90% or more of each is filled with the heat radiation resin to form the heat radiation resin portion 107.

  The heat-dissipating resin of the heat-dissipating resin part 107 is preferably a silicone resin, urethane resin, or epoxy resin, and it is desirable that the thermal conductivity be as high as possible, and at least a certain height from the conventional bottom surface (for example, It is desirable that the heat conductivity is higher than the heat conductivity of the heat-dissipating resin of the conventional transformer that has been buried up to a height higher than the winding portion. For example, for a transformer having a thermal conductivity of 2 W / m · K or more and a large amount of heat generated by the windings 105 and 106 (for example, a heating value of the windings 105 and 106 of 5 W or more), 3 W / m・ It is desirable to be K or more.

  Further, as shown in FIG. 3B, the inner bobbin 101 has a contact portion 101e with the heat sink. In addition, the cover 103 has a contact portion 103 e with the heat sink 108. For this reason, the inner bobbin 101 and the cover 103 have contact portions 101e and 103e with the heat sink 108, respectively, and a main path for heat dissipation of the inner winding 105 and the outer winding 106 (the heat dissipation path will be described later). Become. For this reason, it is desirable that the materials of the inner bobbin 101 and the cover 103 have a thermal conductivity equal to or higher than that of the heat radiation resin. For example, for a transformer with 2 W / m · K or more and a large amount of heat generated by the windings 105 and 106, use a material with a thermal conductivity of 3 W / m · K or more as the inner bobbin 101 and the cover 103. Is desirable.

  Next, the heat dissipation path of the transformer 100 in the first embodiment of the present invention will be described.

  First, the heat dissipation path 151 of the inner winding 105 will be described. Basically, the inner winding 105 does not radiate heat to the outer bobbin side, but radiates heat via the inner bobbin 101. 3A and 3B, as indicated by the heat dissipation path 151 of the inner winding 105, the heat generated by the inner winding 105 is radiated to the gap 181 between the inner bobbin 101 and the inner winding 105 inside and outside the magnetic path of the magnetic core 104. The heat conducting resin part 107 formed by filling the resin, the inner bobbin winding part 101a, the lower inner bobbin flange part 101b, and the inner winding 105 are conducted. As shown in FIG. 3B, the conducted heat is outside the magnetic path of the magnetic core 104 on both sides in the longitudinal direction of the transformer 100, and the heat radiation resin in which the heat radiation resin is filled in the gap 182 between the inner bobbin 101 and the inner winding 105. Conduction is conducted to the heat sink 108 via the portion 107 and the lower end contact portion 101e of the inner bobbin 101 with the heat sink 108. Therefore, the temperature of the inner winding 105 at the time of operation can be set to a specified value or less.

  Next, the heat dissipation path for heat generation of the outer winding 106 will be described. Basically, the outer winding 106 does not radiate heat to the inner bobbin side, but radiates heat through the cover 103. 3B and 3C, as indicated by the heat dissipation path 152 of the outer winding 106, the heat generated by the outer winding 106 is conducted through the outer winding 106 in the magnetic path of the magnetic core 104. Next, as shown in FIG. 3B, outside of the magnetic path of the magnetic core 104 on both sides in the longitudinal direction of the transformer 100, the heat radiation resin portion 107 and the cover 103 are filled in the gap 188 between the outer winding 106 and the cover 103. Conduction is conducted to the heat sink 108 through the lower end contact portion 103e with the heat sink 108. Therefore, the temperature of the outer winding 106 during operation can be set to a specified value or less.

  As shown in FIG. 3C, since the inner winding 105 is located inside the transformer 100, the heat for the total heat generated by the transformer 100 is increased, and a high heat dissipation capability is required to dissipate the heat. Therefore, high heat dissipation capability is obtained by filling the heat radiation resin into almost all the gaps 181 and 182 between the inner bobbin 101 and the inner winding 105 to form the heat radiation resin portion 107. Further, if there is a heat radiation resin in the magnetic path of the magnetic core 104, heat conduction is performed to the magnetic core 104 and the temperature of the magnetic core 104 is increased, so the gap 183 between the inner winding 105 and the outer bobbin 102 in the magnetic path is increased. In addition, each of the gap 185 between the outer bobbin 102 and the outer winding 106 in the magnetic path and the gap 187 between the outer winding 106 and the cover 103 in the magnetic path is not filled with a heat-dissipating resin. 109 is formed so as not to dissipate heat, while the space 188 between the outer winding 106 outside the magnetic path and the cover 103 is filled with heat dissipating resin to form a heat dissipating resin portion 107 to dissipate heat. In the set device incorporating the transformer 100, the temperature of the magnetic core 104 located on the outermost periphery of the transformer 100 rises due to the influence of heat generated by peripheral components. It is necessary to reduce the heat conduction to 104 and reduce the temperature rise of the magnetic core 104.

  Next, the manufacturing method of the transformer 100 according to the first embodiment of the present invention will be described with reference to FIG.

  First, a heat radiation resin is applied to the inner bobbin winding portion 101 a of the inner bobbin 101.

  Next, the inner winding 105 is wound around the inner bobbin winding portion 101a. As a result, the heat radiation resin portion 107 is formed in a gap 181 between the inner bobbin 101 and the inner winding 105 and a gap 182 between the inner bobbin 101 and the inner winding 105 outside the magnetic path of the magnetic core 104 described later. Become.

  Next, the outer bobbin 102 is fitted from above the inner bobbin 101. As a result, a space 109 that is not filled with the heat-dissipating resin is formed in a gap 183 between the inner winding 105 and the outer bobbin 102 in the magnetic path of the magnetic core 104 described later.

  Next, the outer winding 106 is wound around the outer bobbin winding portion 102a. The number of turns of the inner winding 105 and the outer winding 106 is determined by the converted voltage value by the transformer 100.

  Next, a heat radiation resin is applied to at least one of the outside of the outer winding 106 and the inside of the cover 103 that is outside the magnetic path of the magnetic core. As a result, the heat radiating resin portion 107 is formed in the gap 188 between the outer winding 106 and the cover 103 outside the magnetic path of the magnetic core 104.

  Next, the pair of covers 103 are fitted into the outer bobbin 102. As a result, a gap 185 between the outer bobbin 102 and the outer winding 106 in the magnetic path of the magnetic core 104 and a gap 187 between the outer winding 106 and the cover 103 in the magnetic path of the magnetic core 104 are respectively obtained. Then, the space 109 that is not filled with the heat radiation resin is formed. The heat-dissipating resin of each heat-dissipating resin part 107 is cured at room temperature or high temperature in accordance with the heat-dissipating resin curing method. When curing at high temperature, heat curing is performed at this stage.

  Next, the divided magnetic cores 104 are fitted from above and below the inner bobbin hollow cylinder portion 101c and the outer bobbin hollow cylinder portion 102c, and the legs 104a of the magnetic core 104 are brought into contact with each other. Note that when the legs 104a of the magnetic core 104 are brought into contact with each other, a gap may be provided between the legs 104a. The magnetic core 104 is bonded using an adhesive, or the outer periphery thereof is fixed with a tape-like one, or is fixed with a spring-like one.

  The inner bobbin 101 and the outer bobbin 102 are fitted into the inner bobbin unit in which the inner winding 105 is wound around the inner bobbin winding portion 101a and the outer side in which the outer winding 106 is wound around the outer bobbin winding portion 102a. The bobbin unit may be manufactured in advance, and the outer bobbin unit may be fitted from above the inner bobbin unit.

  Further, the heat radiation resin filling the gap 188 between the outer winding 106 and the cover 103 is applied to the outer winding 106 after the outer winding 106 is wound, and the pair of covers 103 are fitted from both sides of the outer bobbin 102. Thus, the heat radiating resin portion 107 may be formed in the gap 188.

  Through the steps as described above, the transformer 100 according to the first embodiment of the present invention can be manufactured.

  Next, the transformer 200 according to the second embodiment of the present invention will be described below with reference to FIGS. 4A, 4B, and 4C. 4A is a sectional end view taken along the line 4A-4A in FIG. 1, FIG. 4B is a sectional end view taken along the line 4B-4B in FIG. 1, and FIG. 4C is a sectional view taken along the line 4C-4C in FIG. is there. 4A, 4B, and 4C, the same components as those in FIGS. 3A, 3B, and 3C are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIG. 4C, the transformer 200 in the second embodiment of the present invention is the first of the present invention.
The gap 184 between the inner winding 105 outside the magnetic path of the magnetic core 104 and the outer bobbin 102 and the gap between the outer bobbin 102 outside the magnetic path of the magnetic core 104 and the outer winding 106 with respect to the transformer 100 in the embodiment. Each of the 186 and 186 is filled with a heat radiating resin to form the heat radiating resin portion 107, so that the heat generated by the inner winding 105 and the outer winding 106 of the transformer 100 can be transferred to the heat sink via the inner bobbin 101 and the cover 103. The heat is dissipated to 108, and the temperature of each part of the transformer during operation can be set to a predetermined value or less.

  4A shows that in the magnetic path formation region 180, the heat radiation resin is filled in the gap 181 between the inner bobbin 101 and the inner winding 105 to form the heat radiation resin portion 107. FIG. FIG. 4B shows the gap 182 between the inner bobbin 101 and the inner winding 105, the gap 184 between the inner winding 105 and the outer bobbin 102, and between the outer bobbin 102 and the outer winding 106 except for the magnetic path forming region 180. It shows that the gap 186 and the gap 188 between the outer winding 106 and the cover 103 are filled with the heat radiation resin to form the heat radiation resin portion 107.

  Next, the heat dissipation path of the transformer 200 according to the second embodiment of the present invention will be described. A heat dissipation path 153 is added to the heat dissipation path of the transformer 100 as shown in FIGS. 4B and 4C. With respect to the transformer 100, the gap 184 between the inner winding 105 and the outer bobbin 102 and the gap 186 between the outer bobbin 102 and the outer winding 106 are also filled with heat radiation resin to form a heat radiation resin portion 107. The heat generated by the inner winding 105 and the outer winding 106 is conducted from the higher temperature side to the lower temperature side, and is conducted to the heat sink 108 via the contact portion 101e or 103e of the inner bobbin 101 or the cover 103 with the heat sink 108. To do. 4B and 4C show a case where the temperature of the inner winding 105 is higher than that of the outer winding 106, and heat generated in the inner winding 105 is conducted to the outer winding 106 and the cover 103 through the heat radiation path 153. It shows that. At this time, since the gap 184 between the inner winding 105 and the outer bobbin 102 and the gap 186 between the outer bobbin 102 and the outer winding 106 are outside the magnetic path formed by the magnetic core 104, heat conduction is performed to the magnetic core 104. The temperature of the core 104 is not increased. Since the transformer 200 is provided with a heat dissipation path 153 with respect to the transformer 100, the transformer 200 can have higher heat dissipation performance without increasing the temperature of the magnetic core 104, and has higher power. Effective for heat dissipation of transformer.

  Next, the manufacturing method of the transformer 200 according to the second embodiment of the present invention will be described with reference to FIG.

  The following points are different from the manufacturing process of the transformer 100.

  Before the outer bobbin 102 is fitted from above the inner bobbin 101, a heat radiation resin is applied to the inner winding 105. Alternatively, a heat radiation resin is applied to the inside of the outer bobbin 102. After that, by inserting the outer bobbin 102 from above the inner bobbin 101, the heat radiating resin portion 107 filled with the heat radiating resin in the gap 184 between the inner winding 105 outside the magnetic path of the magnetic core 104 and the outer bobbin 102 is provided. Will form.

  Further, before winding the outer winding 106 around the outer bobbin winding part 102a, a heat radiation resin is applied to the outer bobbin winding part 102a. After that, by winding the outer winding 106 around the outer bobbin winding portion 102a, the heat dissipation in which the air gap 186 between the outer bobbin 102 outside the magnetic path of the magnetic core 104 and the outer winding 106 is filled with the heat dissipation resin is filled. The resin part 107 is formed.

  Through the steps as described above, the transformer 200 according to the second embodiment of the present invention can be manufactured.

  According to the transformers 100 and 200 according to the first and second embodiments described above, it is not necessary to fill a certain height (for example, a height higher than the winding portion) from the bottom surface with the heat radiation resin. Thus, a light-weight and low-cost transformer that ensures heat dissipation performance can be provided. Moreover, according to the transformer 200 according to the second embodiment, since the heat dissipation path 153 is added to the transformer 100, the heat dissipation performance can be further improved without increasing the temperature of the magnetic core 104. It is also effective for heat dissipation of transformers with higher power.

  In addition, it can be made to show the effect which each has by combining arbitrary embodiment or modification of the said various embodiment or modification suitably. In addition, combinations of the embodiments, combinations of the examples, or combinations of the embodiments and examples are possible, and combinations of features in different embodiments or examples are also possible.

  The transformer and the method for manufacturing the transformer according to the above aspect of the present invention have a high conversion efficiency and a large current capacity, and include a DC / DC converter for a power supply system in a wide range of fields such as automobiles, the environment, housing, and infrastructure, It is useful as a transformer that can be applied to applications such as a DC converter.

100, 200 Transformer 101 Inner bobbin 101a Inner bobbin winding part 101b Inner bobbin collar part 101c Inner bobbin hollow cylinder part 101e Lower end contact part 102 Outer bobbin 102a Outer bobbin winding part 102b Outer bobbin collar part 102c Outer bobbin hollow cylinder part 103 Cover 103e Lower end contact portion 104 Magnetic core 105 Inner winding 106 Outer winding 107 Heat radiation resin portion 108 Heat sink 109 Space portion 120 Coil unit 121 Magnetic core unit 151, 152, 153 Heat radiation path 180 Magnetic path formation region 181, 182 Inner bobbin-inner Air gap between windings 183, 184 Air gap between inner winding and outer bobbin 185, 186 Air gap between outer bobbin and outer winding 187, 188 Air gap between outer winding and cover 10 Transformer 11 Inner bobbin 12 Outer bobbin 13 Cover 14 Magnetic Core 15 Inner Winding 16 Outer Winding 17 Case 18 Heat Dissipation Resin

Claims (4)

An inner winding wound around an inner bobbin, an outer bobbin wrapped around the inner winding, an outer winding wound around the outer bobbin, and a cover wrapped around the outer winding. A coil unit formed with
A magnetic core unit in which a magnetic core is inserted from above and below the inner bobbin and the outer bobbin of the coil unit, and a magnetic path is formed in a direction perpendicular to a winding direction of the inner winding and the outer winding; and
At least a gap between the inner bobbin and the inner winding inside the region where the magnetic path of the magnetic core is formed, and the inner bobbin outside the region where the magnetic path of the magnetic core is formed And the gap between the outer winding and the cover outside the region where the magnetic path of the magnetic core is formed are filled with heat radiation resin to dissipate heat. Forming the resin part,
And the gap between the magnetic cores wherein the magnetic path and the inner winding of the inner region being formed the outer bobbin, and inside the outer bobbin of the region where the magnetic path of the magnetic core is formed The space between the outer winding and the gap between the outer winding and the cover inside the region where the magnetic path of the magnetic core is formed is a space that is not filled with heat radiation resin. Transformer as part. And the gap between the outside of said outer bobbin and the inner winding of the region where the magnetic path of the magnetic core is formed, and the outer bobbin outside the area in which the magnetic path of the magnetic core is formed The transformer according to claim 1, wherein a heat radiation resin portion filled with a heat radiation resin is formed in each gap between the outer windings. After applying a heat radiation resin to the winding part of the inner bobbin, winding the inner winding around the inner bobbin;
Winding the outer winding around the outer bobbin;
Inserting the outer bobbin into the inner bobbin,
After the three steps, heat dissipation resin is applied to at least one of the outside of the outer winding or the inside of the cover, which is outside the region where the magnetic path of the magnetic core is formed ,
A coil unit is formed by fitting the cover to the outer bobbin fitted to the inner bobbin,
Inserting the magnetic core from above and below the inner bobbin and the outer bobbin of the coil unit, forming a magnetic path in a direction perpendicular to the winding direction of the inner winding and the outer winding,
At least a gap between the inner bobbin and the inner winding inside the region where the magnetic path of the magnetic core is formed, and the inner bobbin outside the region where the magnetic path of the magnetic core is formed Radiating heat with a heat-dissipating resin applied to each of the gap between the inner winding and the gap between the outer winding and the cover outside the region where the magnetic path of the magnetic core is formed. A method of manufacturing a transformer in which a resin part is formed. Prior to the step of fitting the outer bobbin into the inner bobbin, a heat radiation resin is applied to at least one of the outer side of the inner winding or the inner side of the outer bobbin that is outside the region where the magnetic path of the magnetic core is formed. Applying step;
Before the step of winding the outer winding around the outer bobbin, after applying a heat radiation resin to the winding portion of the outer bobbin that is outside the region where the magnetic path of the magnetic core is formed , The method for manufacturing a transformer according to claim 3, further comprising a step of winding the outer winding.

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