Patent Application
20240321499
The present invention relates to a coil device.
JP 2014-93404 A describes a coil device including a tubular bobbin, a first winding portion and a second winding portion disposed on the outer circumferential surface of the bobbin, and an E-shaped core attached to the bobbin and including a middle leg and an outer leg. The middle leg is inserted into the through hole of the bobbin, and is disposed radially inside the first winding portion and the second winding portion. The outer leg is disposed radially outside the first winding portion and the second winding portion.
In the coil device of JP 2014-93404 A, when the above-described members are combined, for example, a space is inevitably formed between the bobbin and the middle leg. According to investigations by the present inventors, it has been found that such a space may hinder heat dissipation and miniaturization of the coil device.
The present invention has been made in view of such circumstances, and an object thereof is to provide a coil device that has excellent heat dissipation and can be downsized.
In order to achieve the above object, a coil device according to the present invention includes:
In the coil device according to the present invention, at least one of the inner circumferential surface of the first winding portion and the inner circumferential surface of the second winding portion is in contact with the outer circumferential surface of the middle leg core. This prevents a space from being formed between the middle leg core and at least one of the first winding portion and the second winding portion, thereby reducing the size of the coil device. This also facilitates direct heat transfer of heat generated in at least one of the first winding portion and the second winding portion to the middle leg core, thereby improving the heat dissipation of the coil device. In addition, since the bobbin is not interposed between the middle leg core and at least one of the first winding portion and the second winding portion, the coil device can be downsized by the thickness of the bobbin.
At least one of the first wire and the second wire may be directly wound around the outer circumferential surface of the middle leg core. In this case, at least one of the inner circumferential surface of the first winding portion and the inner circumferential surface of the second winding portion comes into contact with the outer circumferential surface of the middle leg core. This prevents a space from forming between the middle leg core and at least one of the first winding portion and the second winding portion, and effectively reduces the size of the coil device and improves heat dissipation.
An inner circumferential surface of the outer leg core may be in contact with at least one of the outer circumferential surface of the first winding portion and the outer circumferential surface of the second winding portion. In this case, a space is less likely formed between the outer leg core and at least one of the first winding portion and the second winding portion. This ensures a heat transfer path between the outer leg core and at least one of the first winding portion and the second winding portion, thereby effectively reducing the size of the coil device and improving its heat dissipation.
The outer leg core may be configured to be separated from the middle leg core. In this case, the first wire and the second wire can be wound around the middle leg core separated from the outer leg core. This allows the first wire and the second wire to be wound around the middle leg core without being inhibited by the outer leg core, thereby facilitating the winding operation of the first wire and the second wire.
The middle leg core may be configured to be separated from the first combining core. In this case, the first wire and the second wire can be wound around the middle leg core separated from the first combining core (that is, with the middle leg core alone). Therefore, the first wire and the second wire can be easily wound around the middle leg core.
The outer leg core may be configured to be separated from the first combining core. In this case, the outer leg core, the middle leg core, and the first combining core are separated from each other. Therefore, the outer leg core can be disposed more freely, and for example, the outer leg core can be disposed such that the inner circumferential surface of the outer leg core is in contact with at least one of the outer circumferential surface of the first winding portion and the outer circumferential surface of the second winding portion. In this case, a space is less likely formed between the outer leg core and at least one of the first winding portion and the second winding portion, and a heat transfer path can be secured between the outer leg core and at least one of the first winding portion and the second winding portion. This effectively reduces the size of the coil device and improves heat dissipation.
The middle leg core includes a first split core having the first wire spirally wound, and a second split core formed separately from the first split core and having the second wire spirally wound, and a first gap may be formed between the first split core and the second split core. In this case, the distance between the first winding portion and the second winding portion can be adjusted by the first gap, and the coupling between the first winding portion and the second winding portion can be adjusted. Accordingly, leakage of the coil device can be optimized.
A second combining core facing the first combining core may be further provided along the axial direction of the middle leg core, and a second gap may be formed between an axial end of the middle leg core and the second combining core. In this case, the coupling between the first winding portion and the second winding portion can be adjusted by the second gap, and the leakage of the coil device can be optimized.
At least one of the first wire and the second wire is an insulated coated wire, and a coating of the insulating coated wire of at least one of the first winding portion and the second winding portion may be covered with a resin. In this case, the shape of at least one of the first winding portion and the second winding portion can be maintained by the resin. This prevents unwinding of at least one of the first winding portion and the second winding portion, thereby improving the magnetic properties of the coil device.
A case accommodating the middle leg core and the outer leg core may be further provided, the case may be filled with a heat dissipation resin so as to cover the first winding portion and the second winding portion. In this case, the heat of the first winding portion, the second winding portion, and the core can be dissipated via the heat dissipation resin and the case.
A first combining core coupling the middle leg core with the outer leg core, a second combining core facing the first combining core along the axial direction of the middle leg core, and a heat sink having a top plate portion disposed along the top surface of the second combining core and a side portion disposed along a side surface of the second combining core perpendicular to a top surface may be further provided. In this case, in particular, the heat of the second combining core can be dissipated via the top plate portion and the side portion of the heat sink.
Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the illustrated contents are merely schematic and exemplary for understanding the present invention, and the appearance, the dimensional ratio, and the like may be different from the actual ones. Further, the present invention is not limited to the following embodiments.
A coil device 1 according to the first embodiment of the present invention illustrated in
In
As illustrated in
The first wire 4 and the second wire 5 are self bonding wires. As illustrated in the enlarged view in
Although not illustrated in detail, the fusion layers 44 and 54 are melted by heating the first wire 4 and the second wire 5. As a result, the turns constituting the first winding portion 40 are fixed (bonded) to each other by the fusion layer 44 (adhesive layer), and the first winding portion 40 is covered with the fusion layer 44 over the coating 43. This allows the first winding portion 40 to be self-retaining and stabilizes the shape of the first winding portion 40. In addition, the turns constituting the second winding portion 50 are fixed (bonded) to each other by the fusion layer 54 (adhesive layer), and the second winding portion 50 is covered with the fusion layer 54 over the coating 53. This allows the second winding portion 50 to be self-retaining and stabilizes the shape of the second winding portion 50. In the present embodiment, both the first wire 4 and the second wire 5 are self bonding wires, but only one of the first wire 4 and the second wire 5 may be a self bonding wire.
At least one of the first wire 4 and the second wire 5 may be an insulated coated wire that is not a self bonding wire. Further, the first winding portion 40 may be covered with a resin over the coating 43 (or the core portion 42) by, for example, resin impregnation or varnish impregnation. Similarly, the second winding portion 50 may be covered with a resin over the coating 53 (or the core portion 52) by, for example, resin impregnation or varnish impregnation. In this case, the shapes of the first winding portion 40 and the second winding portion 50 can be maintained by the resin. This prevents unwinding of the first winding portion 40 and the second winding portion 50 and improves the magnetic properties of the coil device 1.
a diameter of each of the first wire 4 and the second wire 5 is, for example, 1.0 to 3.0 mm. Diameters of the first wire 4 and the second wire 5 may be equal to each other or may be different from each other. For example, the diameter of one of the first wire 4 and the second wire 5 having a larger current may be made larger than the diameter of the other wire.
As illustrated in
The middle leg core 2 includes a first split core 21 and a second split core 22 formed separately from the first split core 21. The first split core 21 and the second split core 22 are combined in the Z axis direction via the gap member 10 (
The first split core 21 is formed of a columnar body, and the cross-sectional shape of the first split core 21 is elliptical. However, the cross-sectional shape of the first split core 21 may be circular, rectangular, or other polygonal. The second split core 22 includes a columnar body and has the same shape as the first split core 21. However, the shape of the second split core 22 may be different from the shape of the first split core 21. The axial length of the second split core 22 may be longer (or shorter) than the axial length of the first split core 21.
The material of the first split core 21 and the second split core 22 is not particularly limited, but is a synthetic resin in which ferrite particles or metal magnetic particles are dispersed. The ferrite particles are not particularly limited, and examples thereof include Ni—Zn-based ferrite and Mn—Zn-based ferrite. The metal magnetic particles are not particularly limited, and examples thereof include Fe—Ni alloy powder, Fe—Si alloy powder, Fe—Si—Cr alloy powder, Fe—Co alloy powder, Fe—Si—Al alloy powder, and amorphous iron. The synthetic resin is not particularly limited, and examples thereof include epoxy resins, phenol resins, polyester resins, polyurethane resins, polyimide resins, and silicon resins. The materials of the first split core 21 and the second split core 22 are the same, but may be different.
The second split core 22 is disposed on the first combining cores 6a and 6b so as to overlap the first combining core 6a and the first combining core 6b. The second split core 22 is disposed at the center of the first combining cores 6a and 6b in the Y axis direction, but the position of the second split core 22 may be displaced with respect to the center of the first combining cores 6a and 6b in the Y axis direction.
As illustrated in
The gap member 10 is an insulating sheet, and is disposed (sandwiched) between the first split core 21 and the second split core 22. The cross-sectional shape of the gap member 10 is the same as the cross-sectional shape of the first split core 21 or the second split core 22. The gap member 10 is made of, for example, plastic such as PPS, PET, PBT, or LCP, or other insulating member (preferably a heat-resistant material). The thickness of the gap member 10 is smaller than the thickness of the first split core 21 or the second split core 22. The thickness of the gap member 10 along the Z axis is, for example, 1 to 3 mm. Further, the thickness of the gap member 10 is smaller than the diameter of the first wire 4 or the second wire 5, but may be equal to or larger than this.
In the present embodiment, a gap (region where no core is disposed) is formed between the first split core 21 and the second split core 22 by the gap member 10, and the distance between the first split core 21 and the second split core 22 along the Z axis can be adjusted. Therefore, the distance along the Z axis between the first winding portion 40 disposed in the first split core 21 and the second winding portion 50 disposed in the second split core 22 can be adjusted. Thus, the coupling between the first winding portion 40 and the second winding portion 50 can be adjusted, and the leakage of the coil device 1 can be optimized.
Both the first winding portion 40 and the second winding portion 50 are disposed so as not to overlap with the gap member 10. That is, the first winding portion 40 is disposed on one side of the gap member 10 along the Z axis. The second winding portion 50 is disposed on the other side of the gap member 10 along the Z axis. This makes it easy to obtain the effect of adjusting the coupling between the first winding portion 40 and the second winding portion 50 described above.
The gap member 10 may be omitted, and an air layer (space) may be formed between the first split core 21 and the second split core 22. For example, the first split core 21 is combined to the second combining cores 7a and 7b to form a T-shaped core, and the second split core 22 is combined to the first combining cores 6a and 6b to form a T-shaped core, thereby forming a gap (air layer) between the first split core 21 and the second split core 22.
The length of the first split core 21 along the Z axis is equal to the length of the first winding portion 40 along the Z axis, but may be longer than this. The length of the second split core 22 along the Z axis is equal to the length of the second winding portion 50 along the Z axis, but may be longer than this.
As illustrated in
The outer leg core 3a is disposed on the first combining cores 6a and 6b so as to overlap the first combining core 6a and the first combining core 6b on one side in the Y axis direction with respect to the middle leg core 2. The outer leg core 3b is disposed on the first combining cores 6a and 6b so as to overlap the first combining core 6a and the first combining core 6b on the other side in the Y axis direction with respect to the middle leg core 2.
As illustrated in
The outer leg core 3a includes one core, but may include cores. The outer leg core 3b includes one core, the outer leg core 3b may include cores. For example, similarly to the middle leg core 2, the outer leg core 3a may include split cores disposed along the Z axis via at least one gap member. In addition, the outer leg core 3b may include split cores disposed along the Z axis via at least one gap member.
As illustrated in
The inner circumferential surface 30 of the outer leg core 3b is a curved surface, and is curved along the outer circumferential surface of the first winding portion 40 and the outer circumferential surface of the second winding portion 50. The radius of curvature of the inner circumferential surface 30 of the outer leg core 3b is equal to the radius of curvature of the outer circumferential surface of each of the first winding portion 40 and the second winding portion 50, but may be smaller or larger than this.
The thickness (maximum thickness or average thickness) of the outer leg core 3a or 3b in the Y axis direction is smaller than the thickness (maximum thickness or average thickness) of the middle leg core 2 in the Y axis direction, but may be equal to or larger than this.
Each of the first combining cores 6a and 6b is a plate-shaped core that is flat in the Z axis direction. The first combining core 6a and the first combining core 6b have the same shape, but may have different shapes. The materials of the first combining cores 6a and 6b are not particularly limited, but are synthetic resins in which ferrite particles or metal magnetic particles are dispersed. The materials of the first combining cores 6a and 6b are the same, but may be different. The materials of the first combining cores 6a and 6b are the same as the material of the other cores (the middle leg core 2, the outer leg core 3a, and the outer leg core 3b), but may be different.
The first combining cores 6a and 6b are disposed adjacent to each other in the X axis direction (see
As illustrated in
On the inner surface 65 of the first combining core 6b, the middle leg core 2 (second split core 22), the outer leg core 3a, and the outer leg core 3b are disposed. Therefore, the first combining core 6b combines the middle leg core 2 (second split core 22), the outer leg core 3a, and the outer leg core 3b.
Although not illustrated in detail, the middle leg core 2 (second split core 22), the outer leg core 3a, and the outer leg core 3b are disposed on the inner surface 65 of the first combining core 6a illustrated in
As illustrated in
The bottom surface 33 of the outer leg core 3a is in direct contact with the inner surface 65 of the first combining core 6b (as well as the first combining core 6a). Similarly, the bottom surface 33 of the outer leg core 3b is in direct contact with the inner surface 65 of the first combining core 6b (as well as the first combining core 6a). However, an insulating or conductive member may be disposed between the bottom surface 33 of the outer leg core 3a and the inner surface 65 of the first combining core 6b (first combining core 6a). Similarly, an insulating or conductive member may be disposed between the bottom surface 33 of the outer leg core 3b and the inner surface 65 of the first combining core 6b (first combining core 6a).
As illustrated in
Although the first combining core 6a and the first combining core 6b are configured to be separated, they may be integrated. Alternatively, the first combining core 6a may be further divided into cores, and the first combining core 6b may be further divided into cores.
Each of the second combining cores 7a and 7b is a plate-shaped core that is flat in the Z axis direction. The second combining core 7a and the second combining core 7b have the same shape, but may have different shapes. The material of the second combining cores 7a and 7b is not particularly limited, but is a synthetic resin in which ferrite particles or metal magnetic particles are dispersed. The materials of the second combining cores 7a and 7b are the same, but may be different. The material of the second combining cores 7a and 7b is the same as the material of the other cores (the middle leg core 2, the outer leg core 3a and the outer leg core 3b, and the first combining cores 6a and 6b), but may be different.
The second combining cores 7a and 7b are disposed adjacent to each other in the X axis direction (see
The second combining cores 7a and 7b face the first combining cores 6a and 6b along the axial direction of the middle leg core 2. As illustrated in
The outer leg cores 3a and 3b are disposed on an inner surface 75 of the second combining core 7b (as well as the second combining core 7a). Therefore, the second combining core 7b combines the outer leg core 3a with the outer leg core 3b. The second combining core 7a combines the outer leg core 3a with the outer leg core 3b.
The top surface 25 of the first split core 21 is not in contact with the inner surface 75 of the second combining core 7b. Although not illustrated in detail, the top surface 25 of the first split core 21 is not in contact with the inner surface 75 of the second combining core 7a. That is, a gap G is formed between the top surface 25 of the first split core 21 (the axial end of the middle leg core 2) and the inner surface 75 of the second combining core 7b. Similarly, a gap G is formed between the top surface 25 of the first split core 21 (the axial end of the middle leg core 2) and the inner surface 75 of the second combining core 7a.
Although an air layer (space) is formed in the gap G, the gap G may be filled with, for example, a heat dissipation resin 14 (
The top surface 32 of the outer leg core 3a is in direct contact with the inner surface 75 of the second combining core 7b (as well as the second combining core 7a). Similarly, the top surface 32 of the outer leg core 3b is in direct contact with the inner surface 75 of the second combining core 7b (as well as the second combining core 7a). However, an insulating or conductive member may be disposed between the top surface 32 of the outer leg core 3a and the inner surface 75 of the second combining core 7b (second combining core 7a). An insulating or conductive member may be disposed between the top surface 32 of the outer leg core 3b and the inner surface 75 of the second combining core 7b (second combining core 7a).
As illustrated in
In the present embodiment, the second combining core 7a and the second combining core 7b are configured separately, but may be integrated. Alternatively, the second combining core 7a may be further divided into cores, and the second combining core 7b may be further divided into cores.
The middle leg core 2, the outer leg core 3a, the outer leg core 3b, and the first combining cores 6a and 6b constitute an E-shaped core. The second combining cores 7a and 7b constitute an I-shaped core. That is, in the coil device 1 of the present embodiment, the E-shaped core and the I-shaped core are combined.
In the present embodiment, these cores are combined so that the outer leg cores 3a and 3b are disposed in the space between the combined body of the first combining cores 6a and 6b and the combined body of the second combining cores 7a and 7b.
The outer leg core 3a is configured to be separated from the middle leg core 2, and the outer leg core 3b is configured to be separated from the middle leg core 2. Therefore, the first wire 4 and the second wire 5 can be wound around the middle leg core 2 (the first split core 21 and the second split core 22) separated from the outer leg cores 3a and 3b. This allows the first wire 4 and the second wire 5 to be wound around the middle leg core 2 without being inhibited by the outer leg cores 3a and 3b, thereby facilitating the winding operation of the first wire 4 and the second wire 5.
The outer leg core 3a may be integrated with the middle leg core 2. For example, the outer leg core 3a may be integrated with the middle leg core 2 via the first combining cores 6a and 6b. In this case, the outer leg core 3a, the middle leg core 2, and the first combining cores 6a and 6b form a U-shaped core.
Similarly, outer leg core 3b may be integrated with middle leg core 2. For example, the outer leg core 3b may be integrated with the middle leg core 2 via the first combining cores 6a and 6b. In this case, the outer leg core 3b, the middle leg core 2, and the first combining cores 6a and 6b form a U-shaped core.
The middle leg core 2 is configured to be separated from the first combining cores 6a and 6b. Therefore, the first wire 4 and the second wire 5 can be wound around the middle leg core 2 (the first split core 21 and the second split core 22) separated from the first combining cores 6a and 6b (that is, with the middle leg core 2 alone). This makes it easier to wind the first wire 4 and the second wire 5 around the middle leg core 2. The middle leg core 2 may be integrated with the first combining cores 6a and 6b. In this case, the middle leg core 2 and the first combining cores 6a and 6b can form a T-shaped core.
The outer leg cores 3a and 3b are configured to be separated from the first combining cores 6a and 6b, but may be integrated with the first combining cores 6a and 6b. In this case, the outer leg cores 3a and 3b and the first combining cores 6a and 6b can form a U-shaped core.
As illustrated in
In addition, the inner circumferential surface 55 of the second winding portion 50 is in contact with the outer circumferential surface 24 of the second split core 22. This is because the second wire 5 is directly wound around the outer circumferential surface 24 of the second split core 22. All of the turns forming the inner circumferential surface 55 of the second winding portion 50 are in contact with the outer circumferential surface 24, but any of the turns may not be in contact with the outer circumferential surface 24.
One of the first winding portion 40 and the second winding portion 50 may not be in contact with the outer circumferential surface of the middle leg core 2. In this case, either the first winding portion 40 or the second winding portion 50 may be an air-core coil.
The inner circumferential surface 30 of the outer leg core 3a and the inner circumferential surface 30 of the outer leg core 3b are in contact with the outer circumferential surface 46 of the first winding portion 40. All of the turns forming the outer circumferential surface 46 of the first winding portion 40 are in contact with the inner circumferential surface 30 of the outer leg core 3a, but any of the turns may not be in contact with the inner circumferential surface 30. Similarly, all of the turns forming the outer circumferential surface 46 of the first winding portion 40 are in contact with the inner circumferential surface 30 of the outer leg core 3b, but any of the turns may not be in contact with the inner circumferential surface 30. Either the inner circumferential surface 30 of the outer leg core 3a or the inner circumferential surface 30 of the outer leg core 3b may not be in contact with the outer circumferential surface 46 of the first winding portion 40.
The inner circumferential surface 30 of the outer leg core 3a and the inner circumferential surface 30 of the outer leg core 3b are in contact with the outer circumferential surface 56 of the second winding portion 50. All of the turns forming the outer circumferential surface 56 of the second winding portion 50 are in contact with the inner circumferential surface 30 of the outer leg core 3a, but any of the turns may not be in contact with the inner circumferential surface 30. Similarly, all of the turns forming the outer circumferential surface 56 of the second winding portion 50 are in contact with the inner circumferential surface 30 of the outer leg core 3b, but any of the turns may not be in contact with the inner circumferential surface 30. Either the inner circumferential surface 30 of the outer leg core 3a or the inner circumferential surface 30 of the outer leg core 3b may not be in contact with the outer circumferential surface 56 of the second winding portion 50.
As illustrated in
Similarly, as illustrated in
Either the outer circumferential surface 46 of the first winding portion 40 or the outer circumferential surface 56 of the second winding portion 50 may be in contact with the inner circumferential surface 30 of the outer leg core 3a and/or the inner circumferential surface 30 of the outer leg core 3b.
The second winding portion 50 is disposed at a distance from the inner surface 65 of the first combining core 6b (first combining core 6a) along the Z axis, but may be in contact with the inner surface 65 of the first combining core 6b (first combining core 6a). The first winding portion 40 is disposed at a distance from the inner surface 75 of the second combining core 7b (second combining core 7a) along the Z axis, but may be in contact with the inner surface 75 of the second combining core 7b (second combining core 7a).
As illustrated in
The protrusion 82a is formed at one end of the side portion 81 in the X axis direction, and protrudes outward in the X axis direction from the outer surface of the side portion 81. The protrusion 82a has a first wall portion 82a1, a second wall portion 82a2, and a bottom wall portion 82a3. The first wall portion 82al and the second wall portion 82a2 face each other along the Y axis. The bottom wall portion 82a3 couples the first wall portion 82al with the second wall portion 82a2. The first wall portion 82al, the second wall portion 82a2, and the bottom wall portion 82a3 are continuous so as to form a C shape. The recess 83a is a recess defined by the first wall portion 82a1, the second wall portion 82a2, and the bottom wall portion 82a3, and is formed inside the protrusion 82a.
The protrusion 82b is formed at the other end of the side portion 81 in the X axis direction, and protrudes outward in the X axis direction from the outer surface of the side portion 81. The protrusion 82b includes a first wall portion 82b1, a second wall portion 82b2, and a bottom wall portion 82b3. The first wall portion 82b1 and the second wall portion 82b2 face each other along the Y axis. The bottom wall portion 82b3 couples the first wall portion 82b1 with the second wall portion 82b2. The first wall portion 82b1, the second wall portion 82b2, and the bottom wall portion 82b3 are continuous so as to form a C shape. The recess 83b is a recess defined by the first wall portion 82b1, the second wall portion 82b2, and the bottom wall portion 82b3, and is formed inside the protrusion 82b.
As illustrated in
In the present embodiment, the heat of the first winding portion 40, the second winding portion 50, the middle leg core 2, the outer leg cores 3a and 3b, and the first combining cores 6a and 6b can be efficiently dissipated to the outside via the heat dissipation resin 14 and the case 8, and the cooling efficiency of the coil device 1 can be enhanced.
As illustrated in
The leadout portion 41a is connected to the wire connecting portion 130 of the terminal 13a while being caulked. The leadout portion 41b is connected to the wire connecting portion 130 of the terminal 13b while being caulked. The leadout portion 51a is connected to the wire connecting portion 130 of the terminal 13c while being caulked. The leadout portion 51b is connected to the wire connecting portion 130 of the terminal 13d while being caulked. The leadout portions 41a, 41b, 51a, and 51b may be welded to the wire connecting portion 130. Alternatively, the leadout portions 41a, 41b, 51a, and 51b may be connected to the wire connecting portion 130 by, for example, laser welding, solder, a conductive adhesive, thermocompression bonding, ultrasonic bonding, resistance brazing, ultraviolet curing resin bonding, or the like.
The connection portion 131 is connected to, for example, a mounting substrate. The connection portion 131 protrudes along the Z axis, but may protrude along the X axis or the Y axis.
Each of the terminal fixing plates 11a and 11b is a plate body having a rectangular parallelepiped shape, and is made of, for example, an insulating member. The pedestals 12a and 12b are attached to the case 8 illustrated in
The bottom portion 120 is a plate body having a rectangular shape in plan view. The enclosure portion 121 and the case fixing portion 122 protrude from the outer edge of the bottom portion 120 along the Z axis. The enclosure portion 121 is disposed along the first side to the third side (one long side and two short sides) of the bottom portion 120, and extends to form a C shape. The case fixing portion 122 is disposed along the fourth side (long side) of the bottom portion 120, and protrudes toward the side opposite to the enclosure portion 121. A part of the case fixing portion 122 is located on both sides of the enclosure portion 121 in the Y axis direction.
The terminal fixing plate 11a is disposed on the bottom portion 120 of the pedestal 12a, and the terminal fixing plate 11b is disposed on the bottom portion 120 of the pedestal 12b (see
As illustrated in
As illustrated in
The heat sink 9c is attached to one side of the second combining core 7b in the Y axis direction, and the heat sink 9d is attached to the other side of the second combining core 7b in the Y axis direction. The heat sink 9c and the heat sink 9d are separated from each other along the Y axis.
As illustrated in
The side portion 91 of the heat sink 9a extends along the first side surface 71 of the second combining core 7a, the outer side surface 31 of the outer leg core 3a, and the first side surface 61 of the first combining core 6a. The side portion 91 of the heat sink 9a is in contact with the first side surface 71 and the first side surface 61, but may be separated from the first side surface 71 and the first side surface 61.
The side portion 91 of the heat sink 9b extends along the second side surface 72 of the second combining core 7a, the outer side surface 31 of the outer leg core 3b, and the second side surface 62 of the first combining core 6a. The side portion 91 of the heat sink 9b is in contact with the second side surface 72 and the second side surface 62, but may be separated from the second side surface 72 and the second side surface 62.
Although not illustrated in detail, the side portion 91 of the heat sink 9c illustrated in
Next, the method for producing the coil device 1 is described. First, the members illustrated in
Next, as illustrated in
Further, the inner surface 75 of the second combining core 7a and the inner surface 75 of the second combining core 7b are bonded to the top surface 32 of the outer leg core 3a, and the second combining cores 7a and 7b are combined with the outer leg core 3a. Further, the inner surface 75 of the second combining core 7a and the inner surface 75 of the second combining core 7b are bonded to the top surface 32 of the outer leg core 3b, and the second combining cores 7a and 7b are combined with the outer leg core 3b. At this time, the position of the outer leg core 3a is adjusted such that the inner circumferential surface 30 of the outer leg core 3a abuts on the outer circumferential surface 46 of the first winding portion 40 and the outer circumferential surface 56 of the second winding portion 50. The position of the outer leg core 3b is adjusted such that the inner circumferential surface 30 of the outer leg core 3b abuts on the outer circumferential surface 46 of the first winding portion 40 and the outer circumferential surface 56 of the second winding portion 50.
Next, as illustrated in
Next, the heat sinks 9a and 9b are attached to the second combining core 7a with, for example, an adhesive, and the heat sinks 9c and 9d are attached to the second combining core 7b with, for example, an adhesive. Next, the terminal fixing plate 11a is disposed on the pedestal 12a, and the terminal fixing plate 11b is disposed on the pedestal 12b. Next, each member described above is accommodated or fixed in the case 8, and the inside of the case 8 is filled with the heat dissipation resin 14. The coil device 1 can be produced as described above.
As illustrated in
The first wire 4 is directly wound around the outer circumferential surface 23 of the first split core 21, and the second wire 5 is directly wound around the outer circumferential surface 24 of the second split core 22. Therefore, the inner circumferential surface 45 of the first winding portion 40 is in contact with the outer circumferential surface 23 of the first split core 21, and the inner circumferential surface 55 of the second winding portion 50 is in contact with the outer circumferential surface 24 of the second split core 22. This prevents spaces from forming between the first winding portion 40 and the first split core 21, and further between the second winding portion 50 and the second split core 22, thereby effectively reducing the size of the coil device 1 and improving its heat dissipation.
In addition, the inner circumferential surface 30 of the outer leg core 3a is in contact with the outer circumferential surface 46 of the first winding portion 40 and the outer circumferential surface 56 of the second winding portion 50, and the inner circumferential surface 30 of the outer leg core 3b is in contact therewith. This prevents spaces from forming between the first winding portion 40 and the outer leg core 3a, between the second winding portion 50 and the outer leg core 3a, and between the first winding portion 40 and the outer leg core 3b, and further between the second winding portion 50 and the outer leg core 3b. This ensures a heat transfer path between the first winding portion 40 and the outer leg core 3a, between the second winding portion 50 and the outer leg core 3a, and between the first winding portion 40 and the outer leg core 3b and further between the second winding portion 50 and the outer leg core 3b, thereby effectively reducing the size of the coil device 1 and improving its heat dissipation.
The outer leg cores 3a and 3b are configured to be separated from the first combining cores 6a and 6b. Further, the outer leg cores 3a and 3b, the middle leg core 2, and the first combining cores 6a and 6b are separated from each other. Therefore, the outer leg cores 3a and 3b can be disposed more freely, and as described above, the outer leg cores 3a and 3b can be disposed such that the inner circumferential surfaces 30 of the outer leg cores 3a and 3b are in contact with the outer circumferential surface 46 of the first winding portion 40 and the outer circumferential surface 56 of the second winding portion 50. As a result, the above-described effect can be effectively obtained.
The coil device 1A of the second embodiment illustrated in
As is clear from comparison between
The top surface 25 of the first split core 21 is in contact with the inner surface 75 of the second combining core 7b (as well as the second combining core 7a). However, as in the first embodiment, a gap G may be formed between the top surface 25 of the first split core 21 and the second combining core 7b (second combining core 7a).
Also in the present embodiment, the same effects as those of the first embodiment can be obtained. In addition, in the present embodiment, the height of the coil device 1A (but a portion excluding the case 8) along the Z axis can be matched with the heights of the outer leg cores 3a and 3b along the Z axis. Accordingly, the height of the coil device 1A can be reduced.
Note that the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. For example, in each of the above embodiments, the first winding portion 40 and the second winding portion 50 illustrated in
In each of the above embodiments, a core may be formed by combining the first E-shaped core and the second E-shaped core. Alternatively, a core may be formed by combining the E-shaped core and the I-shaped core. Alternatively, the core may be formed by combining at least one U-shaped core and at least one I-shaped core.
In each of the above embodiments, as illustrated in
As illustrated in
In each of the above embodiments, both the first wire 4 and the second wire 5 are insulated coated wires, but either the first wire 4 or the second wire 5 may be an insulated coated wire.
In each of the above embodiments, as illustrated in
In each of the above embodiments, the application example of the present invention to transformers has been described, but the present invention may be applied to coil devices other than transformers.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-048644 | Mar 2023 | JP | national |
