JP4793758B2 - Inductance element - Google Patents

Description

  The present invention relates to an inductance element formed by winding a conductor around a core.

  In a stabilized power supply device, in order to obtain a large current output exceeding 100 A, it is common to reduce the size and weight with a switching power supply. In such a switching type power supply, a square wave voltage obtained by switching of a switching element is smoothed by an LC circuit including a choke coil and a smoothing capacitor to obtain a desired DC output voltage.

  Inductance elements, which are choke coils for large currents, have conventionally employed a structure in which a thick copper wire is wound around a toroidal core, or a thin copper wire is bundled and wound. However, the copper wire is wound thickly, resulting in useless space, the thick copper wire complicates the end treatment with other objects, the copper wire becomes dense at the center of the core, and heat dissipation It had a problem that became difficult.

  On the other hand, for example, Patent Document 1 discloses that a toroidal core made of a magnetic alloy and a case for housing the toroidal core are provided, leads serving as conductors are disposed, and both ends of the leads are joined to a circuit board or the like. What is fixed to the body is disclosed. However, since the lead simply passes through the cylindrical toroidal core, the necessary number of turns of the lead cannot be obtained. In addition, when a large current flows through the lead, heat is concentrated at the center of the toroidal core, so some measure of heat dissipation is required as an inductance element.

  In order to avoid such a problem, the present applicant has previously proposed and filed an inductance element shown in FIGS. 4 to 9 (Japanese Patent Application No. 2006-194003).

  In the figure, a choke coil 101 is mainly composed of an outer peripheral thin copper plate 102 as a conductive coating, a toroidal core 103, and inner peripheral thick copper plates 104 and 105 as conductive members.

  The toroidal core 103 is a core body having a general shape formed by sintering a magnetic material and housed in a hollow annular core case made of, for example, resin for insulation, and is formed in a cylindrical shape as a whole. . The outer thin copper plate 102 is formed by processing a thin copper plate into a shape that partially covers the outer periphery of the toroidal core 103, and covers and holds the annular plate-shaped holding portions 112 and 113 and a part of the outer periphery of the toroidal core 103. A rectangular flat plate-like bridging portion 110 that connects the portions 112 and 113 and a fin portion 111 that extends from one side of the bridging portion 110 are configured.

  A through hole 116 that communicates with the center hole 122 of the toroidal core 103 is formed at the center of the sandwiching portion 112, and a narrow connecting piece 114 projects outwardly from the through hole 116. Similarly, a through hole 117 communicating with the center hole 122 of the toroidal core 103 is formed at the center of the sandwiching portion 113, and a wide connecting piece 115 projects outwardly from the through hole 117. Has been. Accordingly, the connecting pieces 114 and 115 are provided alternately in the vertical direction and protrude in opposite directions.

  In addition, hanging L-shaped holding pieces 118 and 119 are bent and formed at substantially right angles at the opposite ends of the sandwiching portions 112 and 113 that are coupled to the bridging portion 110. On the other hand, installation pieces 120 and 121 project from the lower corners of the bridging portion 10, respectively. For example, when the choke coil 101 is fixed to a printed board or a bar member, the engaging claws 119a and 121a formed on the lower ends of the holding piece 119 and the installation piece 121 facing each other are used as engaged parts such as the printed board. The engaging projections 118a and 120a formed at the lower ends of the holding piece 118 and the installation piece 120, which are opposed to each other, are installed and fixed by, for example, soldering.

  The inner peripheral thick copper plates 104 and 105 are both rod-shaped thick copper plates (so-called bus bars). The inner peripheral thick copper plate 104 is formed with a wide portion 104a at one end thereof, while the other inner peripheral thick plate copper plate 105 is formed with a T-shaped branch portion 105a that is bifurcated in the orthogonal direction at one end thereof. . Since these inner peripheral thick copper plates 104 and 105 are overlapped at the time of assembling the choke coil 101, three insulating sheets 126 to 128 are sandwiched between them in order to ensure insulation between them. The insulating sheet 126 is a sheet-like insulator that is in close contact with the bottom surface of the inner peripheral thick copper plate 104, and side protection portions 130 and 131 that adhere to and protect the side surfaces of the inner peripheral thick copper plate 104 are provided along both longitudinal sides. Established. The insulating sheet 128 is a sheet-like insulator that is in close contact with the upper surface of the inner peripheral thick copper plate 105, and side protection portions 134 and 135 that are in close contact with the side surface of the inner peripheral thick copper plate 105 for protection. (It is drooping in FIG. 4). The insulating sheet 127 is a sheet-like insulator that is inserted between the insulating sheets 126 and 128 and reinforces the insulation between the inner peripheral thick copper plates 104 and 105 together with the insulating sheets 126 and 128, and the inner peripheral thick copper plate 104 on the upper side. The side surface protection parts 132 that protect the side surfaces of the inner peripheral thick plate copper plate 105 and the side surface protection parts 133 that protect the side surfaces of the inner peripheral thick copper plate 105 are alternately erected up and down along both longitudinal sides.

  When the choke coil 101 is assembled, the inner peripheral thick copper plate 104 is inserted between the side surface protection portions 130 and 131 of the insulating sheet 126. Similarly, the inner peripheral thick plate copper plate 105 is inserted into the side surface protection portions 134 and 135 of the insulating sheet 128. Inserted between them, the insulating sheet 128 is attached to the upper surface of the inner peripheral thick copper plate 105. Then, with the insulating sheet 127 sandwiched between the insulating sheets 126 and 128, the inner peripheral thick plate copper plates 104 and 105 are stacked one above the other to form an inner peripheral thick plate copper plate assembly 136 as shown in FIG. At this time, since the inner peripheral thick copper plate 104 is slightly shorter than the lower inner peripheral thick copper plate 105, the inner peripheral thick copper plate 104, 105 is opposite to the branched portion 105a of the inner peripheral thick copper plate 105. A stepped portion is formed by projecting the end portion.

  Next, the toroidal core 103 is inserted inside the thin copper plate 102 for outer periphery so that the sandwiching portions 112 and 113 and the bridging portion 110 correspond to both annular end faces and outer peripheral surfaces of the toroidal core 103, respectively. A thin copper plate for outer periphery 102 is placed on the top. Thereby, the toroidal core 103 is held in close contact with each part of the thin copper plate 102 for outer periphery.

  Subsequently, the inner peripheral thick copper plate assembly 136 is inserted into the through holes 116 and 117 of the sandwiching portions 112 and 113 constituting the outer peripheral thin copper plate 102 and the center hole 122 of the toroidal core 103, and the inner peripheral thick copper plate assembly 136 is inserted. The outer thin copper plate 102 is fixed to the sandwiching portions 112 and 113, respectively. Specifically, the end of the inner peripheral thick copper plate 104 opposite to the wide portion 104a is connected and fixed to the connection piece 114 of the sandwiching portion 112 by, for example, screw fastening, while the branched portion 105a of the inner peripheral thick copper plate 105 is fixed. Then, the connection piece 115 is fixedly connected to the connection piece 115 of the clamping part 113 by, for example, screw fastening.

  Through such a manufacturing process, the choke coil 101 shown in FIGS. 5 to 9 is completed. Note that one end (wide portion 104a) of the inner peripheral thick plate copper plate 104 protruding from the inner peripheral thick plate copper plate assembly 136 and the other end of the inner peripheral thick plate copper plate 105 serve as a connection portion with an external circuit.

  The current flows in from the wide portion 104a of the inner peripheral thick copper plate 104, and flows from the connection piece 114 of the clamping portion 112 to the outer peripheral thin copper plate 102 through the inner peripheral thick copper plate 4. In the outer thin copper case 2, the current reaches the sandwiching portion 113 from the sandwiching portion 112 through the bridging portion 110, and flows from the branch portion 105 a to the thick inner copper plate 105 through the connecting portion 115. Further, when the choke coil 101 is installed, if the holding pieces 118 and 119 are short-circuited by a conductive member (not shown) such as a circuit pattern of a printed circuit board or a bus bar, the holding pieces 118 are connected from the connecting pieces 14 of the sandwiching portion 12. , Current flows through the conductive member, the holding piece 119, and the sandwiching portion 113, and flows from the branch portion 105a to the thick copper plate 105 for the inner periphery through the connection portion 115. The current flowing into the inner peripheral thick copper plate 105 finally flows out to the external circuit through the inner peripheral thick copper plate 105 in the core 103.

In this way, the winding to be wound around the toroidal core 103 is made of a thin copper plate for outer periphery 102 having a large surface area covering the outer peripheral surface of the toroidal core 103, and a plurality of thick plates for inner periphery passing through the center hole 122 of the toroidal core 103. By comprising the copper plates 104 and 105, the outer thin copper plate 102 and the inner thick copper plates 104 and 105 can have a function as a radiator, and the temperature rise of the choke coil 101 is reduced. In addition, the winding structure that combines the thick copper plates 104, 105 for inner circumference and the thin copper plate for outer circumference 102, which is a thin plate, makes it possible to minimize the occupied volume, as well as the winding machine, etc. No large tool is required and assembly is easy.
JP-A-8-172109

  However, in the choke coil 101 corresponding to the conventional inductance element, one side of the outer surface of the toroidal core 103 is covered with the bridging portion 110 of the thin copper plate 102 for outer periphery, but the other side of the outer surface of the toroidal core 103 is held in a pair. Except for the pieces 118 and 119, they are almost exposed, and the deterioration of the heat radiation performance from these portions is inevitable. Further, since the holding pieces 118 and 119 are connected by another conductive member, there is a concern that the copper loss due to the electrical resistance of the portion increases and sufficient heat dissipation performance as an inductance element cannot be obtained.

  Further, the inner peripheral thick copper plates 104 and 105 are provided with a connection portion with an external circuit (not shown), but a reduction in loss at the connection portion has also been demanded. Further, the same loss reduction has been demanded for the connecting portion between the inner peripheral thick copper plates 104 and 105 and the outer peripheral thin copper plate 102.

  Therefore, in view of the above problems, the present invention provides an inductance element that can avoid a partial decrease in heat dissipation performance and reduce copper loss due to current.

  Another object of the present invention is to provide an inductance element that is designed to reduce a loss in a connection portion or a connection portion with an external circuit.

The inductance element according to claim 1 of the present invention includes a core made of a magnetic material provided with a through-hole, a first conductive member inserted into the through-hole, and a first conductive member inserted into the through-hole. A second conductive member insulated from the member, and a third conductive member surrounding the core, wherein the first conductive member is on one end side of the third conductive member and the through hole. The second conductive member is electrically connected to the third conductive member on the other end side of the through hole, and the first conductive member and the second conductive member are electrically connected to each other. The member is connected by two electric paths by the third conductive member .

An inductance element according to a second aspect of the present invention is formed by overlapping the first and second conductive members with an insulating sheet interposed therebetween .

According to a third aspect of the present invention, the inductance element includes the core and the first, second, and third conductive members insulated by an insulating sheet .

In the first aspect of the present invention, the winding to be wound around the core includes a third conductive member having a large surface area covering the outer surface of the core , and first and second conductive members inserted into the through holes of the core. It consists of. If it carries out like this, the performance as a heat radiator which produces a cooling effect can be given to winding itself which generates heat by a large current. In addition, in this case, two electrical paths that are part of the winding are formed in the third conductive member so as to surround not only the outer surface of one side of the core but also the outer surface of the other side . The electrical path efficiently dissipates heat from the entire outer surface of the inductance element, and a partial decrease in heat dissipation performance can be avoided. Furthermore, since current can be distributed in two directions by two electrical paths of the third conductive member which is the same member without interposing another conductive member, copper loss due to this current can be reduced. .

In Claim 2 of this invention, the 1st and 2nd electrically-conductive member is piled up through an insulating sheet.

According to claim 3 of the present invention, the core and the first, second and third conductive members are insulated by the insulating sheet.

  Hereinafter, preferred embodiments of an inductance element according to the present invention will be described with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected to the same location as a prior art example, and it abbreviate | omits as much as possible since description of a common part overlaps.

  FIG. 1 is an exploded perspective view of a choke coil 1 as an inductance element in the present embodiment, and FIG. 2 is an external view of the completed choke coil 1. The choke coil 1 mainly includes an outer peripheral copper case 2 as a conductive covering, a toroidal core 3, and inner peripheral copper plates 4 and 5 as first and second conductive members.

  The toroidal core 3 is a general cylindrical core formed by sintering a magnetic material such as ferrite, and a center hole 6 penetrating the inner peripheral copper plates 4 and 5 is formed in the axial direction. In addition, insulating sheets 7 and 8 are provided to cover the inner and outer peripheral surfaces of the toroidal core 3 for electrical insulation from other members, and both axial end surfaces of the toroidal core 3 are provided. That is, another insulating sheet 9 that covers the front and rear annular end surfaces is provided. These insulating sheets 7, 8, 9 are preferably formed of a resin sheet such as Nomex (registered trademark).

  The outer periphery copper case 2 is formed by processing a copper plate into a shape that partially covers the outer periphery of the toroidal core 3. More specifically, the outer peripheral copper case 2 includes a first circumferential portion 11 formed in a U shape so as to surround one outer surface of the toroidal core 3 as viewed from above, and the other outer surface of the toroidal core 3. A second circumferential portion 12 formed in a U-shape so as to surround is disposed so as to face each other, and a first leg portion 13 that hangs down from the lower end of the first circumferential portion 11 and a second circumferential portion 12. A second leg 14 depending from the lower end of the first leg 13, a first pedestal 15 bent in an L shape from the lower end of the first leg 13, and an L shape from the lower end of the second leg 14. And a second pedestal portion 16 bent into a shape. And the 1st surrounding part 11 is the base end part 11A located facing the front one side annular end surface of the toroidal core 3, the bridge | crosslinking part 11B located facing one side outer peripheral surface of the toroidal core 3, and a toroidal core 3 is formed by connecting a distal end portion 11C positioned facing the rear one-side annular end surface, and similarly, the second circumferential portion 12 is a proximal end portion positioned facing the front other-side annular end surface of the toroidal core 3. 12A, the bridge | crosslinking part 12B located facing the other outer peripheral surface of the toroidal core 3, and the front-end | tip part 12C located facing the back other cyclic | annular end surface of the toroidal core 3 are connected and formed.

  In the outer peripheral copper case 2 in this embodiment, the front end portion 11C of the first peripheral portion 11 and the front end portion 12C of the second peripheral portion 12 are connected to each other, and at least four holes 17 from above the connection portion. The connecting piece 18 having a shape is projected outward. In addition, connecting pieces 20 each having two holes 19 are projected outward from below the base end portions 11A and 12A. Accordingly, the connection pieces 18 and 20 are provided alternately in the vertical direction and protrude in opposite directions. Here, the connecting piece 18 is provided for electrical connection between one inner peripheral copper plate 4 and the outer peripheral copper case 2, and the connecting piece 20 includes the other inner peripheral copper plate 5 and the outer peripheral copper plate 5. It is provided for electrical connection with the copper case 2.

  The pedestal portions 15 and 16 are flat surfaces so that the outer copper case 2 can be placed on another conductor member (not shown) in the power supply device with the pedestal portions 15 and 16 as bottom portions. It is formed in a shape. Further, in order to electrically insulate between the pedestal portions 15 and 16 and the conductive member, a bottom surface portion 9A of the insulating sheet 9 is disposed below the pedestal portions 15 and 16. The bottom surface portion 9A is formed in a rectangular shape so that the entire bottom surface of the pedestal portions 15 and 16 can be placed thereon, and the bent pieces 9B that rise vertically from both end edges of the bottom surface portion 9A are formed in each annular shape of the toroidal core 3. It is arranged facing the end face. As described above, the insulating sheet 9 is provided as a common member that insulates not only the toroidal core 3 and the external component but also the outer peripheral copper case 2 and the external conductive member. Further, a center hole 9C having substantially the same shape as the center hole 6 of the toroidal core 3 is formed in the bent piece 9B, and inner peripheral copper plates 4, 5 and an insulating sheet 27 described later are provided in these center holes 6, 9C. Penetrated.

  The inner circumferential copper plate 4 is made of a rod-shaped copper plate (so-called bus bar) suitable for flowing a large current, and one end thereof is a connection having a plurality of holes 4a for electrical connection with an external circuit (not shown). A wide portion 4b as a portion is formed. Further, at the other end of the inner peripheral copper plate 4, four holes 4 c facing the hole 17 of the connecting piece 18 are formed. On the other hand, another inner peripheral copper plate 5 is also made of a rod-shaped bus bar, and is formed into a T shape as a whole by forming a bifurcated portion 5a which is divided into two in the orthogonal direction at one end thereof. In the branch portion 5a, four holes 5b facing the holes 19 of the connection piece 20 are formed. Further, a connecting portion 5d having a plurality of holes 5c is formed at the other end of the inner peripheral copper plate 5 in order to electrically connect to an external circuit (not shown). Since these inner peripheral copper plates 4 and 5 are overlapped when the choke coil 1 is assembled, an insulating sheet 27 is sandwiched therebetween to ensure insulation between the two.

  The insulating sheet 27 is a sheet-like insulator inserted between the inner peripheral copper plates 4, 5, and includes a side surface protection portion 32 that protects the side surface side of the inner peripheral copper plate 4 that is the upper side, and an inner peripheral surface that is the lower side Side surface protection portions 33 that protect the side surface side of the copper plate 5 are alternately erected up and down along both longitudinal sides. Note that a plurality of insulating sheets may be interposed as such an insulator as in the conventional example.

  Next, the assembly process of the choke coil 1 will be described.

  An assembly is configured in which the inner peripheral copper plates 4 and 5 are vertically stacked with the insulating sheet 27 sandwiched between the inner peripheral copper plates 4 and 5. At this time, since the inner peripheral copper plate 4 is slightly shorter than the lower inner peripheral copper plate 5, the inner peripheral copper plates 4, 5 are opposite to the branch portion 5 a of the inner peripheral copper plate 5. A stepped portion is formed by projecting the end portion. The inner peripheral copper plates 4 and 5 are overlapped in a state slightly shifted in the longitudinal direction, so that the both ends of the assembly 36 are wide with respect to the wide portion 4 a of the inner peripheral copper plate 4 and the branched portion 5 a of the inner peripheral copper plate 5. The opposite ends protrude from each other so that the stepped portions are alternately formed up and down. By forming this step portion, connection to an external circuit (not shown) is facilitated.

  Next, the outer peripheral copper case 2 is mounted on the toroidal core 3 in a state where the insulating sheets 7 and 8 are wound around the entire inner peripheral surface and outer peripheral surface of the toroidal core 3 in advance. Specifically, the bridging portion 11B of the first circumferential portion 11 faces one outer peripheral surface of the toroidal core 3, and the bridging portion 12B of the second circumferential portion 12 faces the other outer circumferential surface of the toroidal core 3. As described above, the toroidal core 3 with the insulating sheets 7 and 8 is inserted into the inner side of the outer peripheral copper case 2 surrounded by the first peripheral portion 11 and the second peripheral portion 12. After that, the insulating sheet 9 is inserted from the lower side of the outer peripheral copper case 2 so that the bent piece 9B is interposed between each annular end surface of the toroidal core 3 and the outer peripheral copper case 2. When the insulating sheet 9 is inserted until the bottom surface portion 9A of the insulating sheet 9 abuts against the bottom surfaces of the pedestal portions 15 and 16, the entire outer surface of the toroidal core 3 is covered with the insulating sheets 7, 8, and 9.

  Subsequently, the hole 4c formed at the other end of the inner peripheral copper plate 4 and the hole 17 of the connecting piece 18 coincide with each other, and the hole 5b formed at one end of the inner peripheral copper plate 5 and the hole 19 of the connecting piece 20 coincide with each other. As described above, the assembly 36 is inserted through the center hole 6 of the toroidal core 3 and the center hole 9C of the insulating sheet 9. In this state, the holes 4c and 17 are used to connect and fix the other end of the inner peripheral copper plate 4 and the connection piece 20 with screws 38 as fastening members, and other holes 5b and 19 are used. Then, the branch portion 5a at one end of the thick inner copper plate 5 and the connection piece 20 are connected and fixed with a screw 39 as a fastening member (see FIG. 2).

  Through such a manufacturing process, the choke coil 1 shown in FIG. 2 is completed. One end of the inner peripheral copper plate 4 protruding from the assembly 36 and the other end of the inner peripheral copper plate 5 serve as terminals for connection to an external circuit.

  The operation of the above configuration will be described below.

FIG. 3 is a schematic cross-sectional view schematically showing a current flow in the choke coil 1. In the figure, the current flows from the wide portion 4 a of the inner peripheral copper plate 4 and flows in two directions through the inner peripheral copper plate 4 from the connection piece 17 to the respective peripheral portions 11 and 12 of the outer peripheral copper case 2. In the outer periphery copper case 2, one of the currents branched to the first circulation portion 11 reaches the base end portion 11 a from the distal end portion 11 C through the bridging portion 11 b and passes through the connection piece 19 from the branch portion 5 a for inner periphery. It flows into the copper plate 5. Further, the other current branched to the second circulating portion 12 reaches the base end portion 12a from the tip end portion 12C via the bridging portion 12b, and flows into the inner peripheral copper plate 5 from the branching portion 5a through the connection piece 19. To do. Then, the current that has flowed into the inner peripheral copper plate 5 flows out through the inner peripheral copper plate 5 to an external circuit that is finally coupled to the connecting portion 5d. At this time, as shown in FIG. 3, two closed circuits that circulate around the toroidal core 3 are formed in parallel inside the choke coil 1, and the current flowing from the inner circumferential copper plate 4 is supplied to the toroidal core 3. It will circulate substantially two or more turns in the central axis direction.

  In this way, by assembling the two inner peripheral copper plates 4 and 5 and the outer peripheral copper case 2 to the toroidal core 3, the choke coil 1 having two or more turns capable of flowing a large current can be configured. A winding to be wound around the toroidal core 3 is composed of a copper case 2 for outer periphery having a large surface area covering the outer peripheral surface of the toroidal core 3 and copper plates 4 and 5 for inner periphery penetrating through the center hole 6 of the toroidal core 3. By doing so, the winding itself that generates heat by a large current can be provided with a function of a radiator that produces a cooling effect, and as a result, the temperature rise of the choke coil 1 can be reduced. In particular, in the present embodiment, the current is distributed evenly in two directions by the first peripheral portion 11 and the second peripheral portion 12 that are integrally formed with the same outer peripheral copper case 2 on the outer periphery of the choke coil 3. Therefore, it is possible to dissipate heat uniformly from the surrounding portions 11 and 12 and thus the entire choke coil 1.

  In addition, since the inner peripheral copper plates 4 and 5 serving as input / output portions of the choke coil 1 are made of metal plates, they can be directly connected to an external circuit such as a bus bar, for example, so that they can be indirectly connected via a printed circuit board or a crimp terminal. Contact resistance can be reduced compared to connection, and connection loss is reduced. In particular, in this embodiment, the wide portion 4b of the inner peripheral copper plate 4 and the external circuit can be fixed with at least four screws (not shown) using the holes 4a. Since the connection portion 5d of the peripheral copper plate 5 and the external circuit can also be fixed with at least four screws (not shown) using the holes 5c, the connection loss between the choke coil 1 and the external circuit Can be reduced. Similarly, the inner peripheral copper plates 4 and 5 and the outer peripheral copper case 2 can be fixed with four or more screws 38 and 39, and the connection loss between these members can be reduced.

  The choke coil 1 uses the effective window area of the coil as much as possible and makes the outer peripheral copper case 2 wider to increase its cross-sectional area as compared with a conventional coil made of a round copper wire, a square copper wire or the like. Therefore, the loss due to copper resistance can be minimized. In addition, since the winding structure is a combination of the outer copper case 2 and the inner copper plates 4 and 5, the occupied volume can be minimized, and a machine such as a winding machine is not required for production. Easy to assemble.

As described above, the choke coil 1 as the inductance element of the present embodiment includes the core made of a magnetic material provided with the central hole 6 that is a through hole, that is, the toroidal core 3, and the first conductive material inserted into the central hole 6. The inner peripheral copper plate 4 as a member , the inner peripheral copper plate 5 as a second conductive member inserted into the central hole 6 and insulated from the inner peripheral copper plate 4, and the third conductive surrounding the toroidal core 3 The outer peripheral copper case 2 is provided as a member , the inner peripheral copper plate 4 is electrically connected to one end side of the outer peripheral copper case 2 and the center hole 6, and the inner peripheral copper plate 5 is the outer peripheral copper plate The case 2 and the other end side of the center hole 6 are electrically connected, and the inner peripheral copper plates 4 and 5 are formed by the outer peripheral copper case 2 so as to be connected by two electrical paths. Yes.

In this way, the winding to be wound around the toroidal core 3 is divided into a copper case 2 having a large surface area covering the outer surface of the toroidal core 3 , and a copper plate 4 for the inner circumference inserted into the center hole 6 of the toroidal core 3. 5 can be provided with the function of a radiator that produces a cooling effect on the winding itself that generates heat due to a large current. In addition, in this case, the first circulating portion 11 and the second circulating portion as two electrical paths that become a part of the winding so as to surround not only the outer surface of one side of the toroidal core 3 but also the outer surface of the other side. Since 12 is formed in the copper case 2 for the outer periphery, the first peripheral portion 11 and the second peripheral portion 12 efficiently dissipate heat from the entire outer surface of the choke coil 1, and a partial heat dissipation performance Can be avoided. Furthermore, the current can be distributed in two directions by the first and second circumferential portions 11 and 12 of the outer circumferential copper case 2 that are the same member without interposing another conductive member. Loss can be reduced.

  In the present embodiment, the wide portion 4b and the connecting portion 5d are formed with four or more holes 4a and 5c through which, for example, screws as fixing tools are inserted. In this way, since the external circuit can be firmly fixed to the wide portion 4b and the connection portion 5d using four or more fixing tools, the loss in the wide portion 4b and the connection portion 5d can be reduced. Can do.

  Further, in this embodiment, four or more holes 4c and 5b through which screws 38 and 39 as fixing tools are inserted are formed in the connecting portion between the inner peripheral copper plates 4 and 5 and the outer peripheral copper case 2. Also in this case, since the inner peripheral copper plates 4 and 5 and the outer peripheral copper case 2 can be firmly fixed at the respective connecting portions by using four or more screws 38 and 39, the loss at the connecting portions can be reduced. Can be reduced.

  In addition, in the choke coil 1 of this embodiment, since the inner peripheral thick copper plates 4 and 5 that are the input / output portions of the choke coil 1 are made of bus bars, they can be directly connected to external wiring, such as printed boards and crimp terminals. The contact resistance can be reduced as compared with the indirect connection via the connection, and the connection loss is reduced. Therefore, copper loss due to current can be reduced.

  In addition, this invention is not limited to the said Example, It can change in the range which does not deviate from the meaning of this invention. The present invention is not limited to a toroidal core, and can be applied to any core having a continuous shape such as a square, a triangle, etc., in which the winding is dense with an inner diameter. Various modifications can be made with respect to the winding structure composed of the combination of the outer peripheral copper case 2 and the inner peripheral copper plates 4 and 5. Further, in addition to the choke coil, the present invention can be applied to various inductance elements, and a fin portion as a heat radiating fin may be provided integrally with the outer copper case 2 in order to improve the heat radiation performance.

It is a disassembled perspective view which shows each component of the inductance element in one preferable Example of this invention. It is a perspective view which shows the completion state of an inductance element same as the above. It is a schematic explanatory drawing which shows the path | route of an electric current same as the above. It is a disassembled perspective view which shows each component of the conventional inductance element. It is a perspective view which shows the completion state of an inductance element same as the above. It is a front view which shows the completion state of an inductance element same as the above. It is a rear view which shows the completion state of an inductance element same as the above. It is a top view which shows the completion state of an inductance element same as the above. It is a right view which shows the completion state of an inductance element same as the above.

1 Choke coil (inductance element)
2 Copper plate for outer periphery ( third conductive member )
3 Toroidal core (core)
4 Copper plate for inner circumference (first conductive member )
5 Inner perimeter copper plate (second conductive member)
6 Center hole (through hole)
7, 8, 9 Insulation sheet
11 First circuit part (route)
12 Second circuit (path)
27 insulation sheet

Claims (3)

A core made of a magnetic material provided with a through hole ;
A first conductive member inserted into the through hole ;
A second conductive member inserted into the through hole and insulated from the first conductive member ;
A third conductive member surrounding the core;
The first conductive member is electrically connected to the third conductive member on one end side of the through hole,
The second conductive member is electrically connected to the third conductive member on the other end side of the through hole,
The inductance element, wherein the first conductive member and the second conductive member are connected by two electric paths by the third conductive member . The inductance element according to claim 1, wherein the first and second conductive members are overlapped with an insulating sheet . The inductance element according to claim 1, wherein the core and the first, second, and third conductive members are insulated by an insulating sheet .

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