JP2019067926A - Transformer - Google Patents

Abstract

To provide a transformer capable of dealing with heavy-current, and excellent in coupling of coils.SOLUTION: A transformer has plate conductors 31, 32 becoming a pair of primary coils, a bobbin 20 having a wound core part 28 where a secondary coil 341 is placed between the primary coils, and a pair of secondary terminals 35, 36 connected, respectively, with wire leads 342, 343, i.e., both ends of a wire 34 constituting the secondary coil 341. At least any one of the secondary terminals 35, 36 is attached to the tip 22a of a first pedestal base 22 extended in the axial direction of the bobbin 20, so as to be placed on the outside of at least any one of the plate conductors 31, 32 in an X axis direction along the axial direction of the wound core part 28.SELECTED DRAWING: Figure 3A

Description

  The present invention relates to a transformer preferably used as, for example, a current transformer.

  As a current transformer for converting alternating current into voltage, for example, a transformer shown in Patent Document 1 below is known. When it is desired to flow a large current to the primary coil in the conventional current transformer, it is conceivable to increase the wire diameter of the wire that constitutes the primary coil.

  However, there is a limit to increasing the wire diameter of the wire that constitutes the primary coil, and it is required to increase the current by another method. Moreover, in the conventional transformer, it has the subject that the coupling | bonding with a primary coil and a secondary coil is bad.

Japanese Patent Application Laid-Open No. 03-180009

  The present invention has been made in view of such circumstances, and an object thereof is to provide a transformer capable of coping with a large current and also excellent in coupling between coils.

In order to achieve the above object, the transformer according to the present invention is
A pair of primary coils,
A bobbin having a winding core portion in which a secondary coil is disposed between the primary coils;
A transformer having a pair of secondary terminals to which wire lead portions which are both ends of a wire constituting the secondary coil are respectively connected,
An axially extending direction of the bobbin such that at least one of the secondary terminals is disposed outside the primary coil along an axial direction of the winding core portion; It is attached to the tip of 1 pedestal.

  In the transformer of the present invention, the secondary coil is disposed between the pair of primary coils. Therefore, the coupling between the primary coil and the secondary coil is improved. In addition, by separating the primary coil into two and connecting these coils with an external circuit, the current that can be flowed in total to the primary coil can be increased, which also contributes to a large current. In addition, the insulation distance can be secured by arranging the secondary terminal of the secondary coil outside the primary coil. Furthermore, miniaturization of the transformer can also be realized.

  Preferably, each of the primary coils has a flat coil portion and a pair of flat lead portions, and the primary coil is disposed between flat surfaces of the flat coil portion. With such a configuration, it is possible to flow a larger current as compared with the case where the primary coil is configured by a wire, and the coupling between the primary coil and the secondary coil is also improved.

  Preferably, each of the flat coil portions is integrated with the inside of a collar portion located on both sides in the axial direction of the winding core portion. By integrating the flat coil portion into the inside of the flange of the bobbin by insert molding or the like, the bobbin can be easily molded, and the transformer can be miniaturized.

  Preferably, the flat plate lead portion protrudes outward from the bottom surface on the mounting surface side of the flange portion to form a primary terminal. With such a configuration, the formation of the primary terminal is easy.

Preferably, the first pedestal is integrated with any of the ridges,
The wire lead portions are respectively connected to the secondary terminals through the mounting-side bottom surface positioned between the pair of flat plate lead portions. Since the wire lead portion is drawn in the direction of the secondary terminal through the bottom surface on the mounting surface side, it is easy to ensure the insulation between the wire lead portion and the magnetic core. In addition, it is easy to ensure insulation between the wire lead portion and the primary terminal.

  Preferably, a lead convex portion for improving the insulation between the flat plate lead portion and the wire lead portion is formed on the mounting side bottom surface through which the wire lead portion passes. With this configuration, the insulation between the flat plate lead portion and the wire lead portion (primary terminal) can be improved.

  Preferably, a coil projection for improving the insulation between the secondary coil and the primary terminal is formed on the bottom surface on the mounting side. With this configuration, the insulation between the secondary coil and the primary terminal is improved.

  Preferably, a terminal protrusion is formed on the bottom surface of the first pedestal on the mounting surface side to improve the insulation between the primary terminal and the secondary terminal. With this configuration, the insulation between the primary terminal and the secondary terminal can be improved.

  Preferably, a top plate is mounted on the opposite side of the mounting surface of the pair of ridges opposite to the mounting surface. The suction head is attracted to the upper surface of the top plate, which facilitates the transport of the transformer.

  Preferably, the bobbin is formed with a through hole passing through the axis of the primary coil and the axis of the pair of secondary coils, and the middle leg of the magnetic core is inserted into the through hole. It is done. Attaching the magnetic core to the bobbin improves the magnetic characteristics of the transformer.

FIG. 1A is a perspective view of a transformer according to an embodiment of the present invention. FIG. 1B is a front view of the transformer shown in FIG. 1A. FIG. 1C is a bottom view of the transformer shown in FIG. 1A. FIG. 2 is an exploded perspective view of the transformer shown in FIG. 1A. FIG. 3A is a cross-sectional view taken along the line IIIA-IIIA shown in FIG. 1A. FIG. 3B is a cross-sectional view taken along the line IIIB-IIIB shown in FIGS. 1A and 3A. FIG. 4 is a perspective view of a primary coil and a primary terminal integrated in the bobbin shown in FIG. FIG. 5 is a perspective view of the secondary terminal integrated in the bobbin shown in FIG.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
The transformer 10 according to the present embodiment shown in FIG. 1A is, for example, an on-vehicle charger for EV (Electric Vehicle: electric transportation equipment), PHV (Plug-in Hybrid Vehicle: plug-in hybrid vehicle), or commuter (vehicle) Alternatively, it is used, for example, as a current transformer in a power supply circuit of home or industrial electric equipment or a power supply circuit of computer equipment.

  As shown in FIG. 2, the transformer 10 has a bobbin 20 and a core portion (magnetic core) 40 formed of a first core 401 and a second core 402. In the drawings, the X axis, the Y axis, and the Z axis are perpendicular to one another, and the Z axis corresponds to the height (thickness) of the transformer 10. Further, the X axis is parallel to the winding axis of the coil section described later, and coincides with the direction in which the first pedestal 22 and the second pedestal 23 of the bobbin 20 are arranged.

  The bobbin 20 has a bobbin main body 21 and a first pedestal 22 and a second pedestal 23 integrally formed on the bobbin main body 21 so as to be opposite to each other in the X axis direction of the bobbin main body 21. The bobbin main body 21 of the bobbin 20 has a core portion 28 around which the wire 34 is wound, and a first collar portion 24 and a second collar portion 26 positioned on both sides in the X-axis direction of the core portion 28. A core leg through hole 29 is formed in the bobbin body 21 so as to penetrate the first collar portion 24, the winding core portion 28 and the second collar portion 26 in the X-axis direction.

  In the present embodiment, the cores 401 and 402 have the same shape, have an E-shaped cross section in the X-Y cross section, and constitute a so-called E-shaped core. In addition, the aspect of the cores 401 and 402 is not limited to the aspect shown in FIG. 2, for example, the cores 401 and 402 may be respectively integrally shape | molded, or the cores 401 and 402 are respectively plural. It may be divided into

  The cores 401 and 402 respectively have a base 44 extending in the Y-axis direction, a pair of side legs 48 and 48 projecting in the X-axis direction from both ends of the base 44 in the Y-axis direction, and the side legs 48. , 48 between the middle in the Y-axis direction and the middle leg 46 projecting in the X-axis direction.

  The middle leg portion 46 is inserted into the core leg through hole 29 of the bobbin 20 from both sides in the X-axis direction. As shown in FIG. 3A, in the core leg through holes 29 of the bobbin 20, the tips of the middle legs 46 may be in contact with each other, but may be in contact with each other so as to face each other across a predetermined gap. It may be configured. By forming the gap, it is possible to adjust the leakage characteristics according to the width of the gap.

  As shown in FIG. 2, the middle legs 46, 46 have a substantially square pole shape so as to match the inner peripheral surface shape of the core leg through hole 29, but the shape is particularly limited Alternatively, it may be changed in accordance with the shape of the core leg through holes 29. The side legs 48, 48 have a shape that matches the end surface shape of the ridges 24, 26 in the Y-axis direction, and the outer surface thereof is a plane parallel to the XZ plane (a plane including the X axis and the Z axis) Have. In the present embodiment, the material of each of the cores 401 and 402 may be a soft magnetic material such as metal or ferrite, but is not particularly limited.

  The first pedestal 22 extends from the lower side in the Z-axis direction of the first collar portion 24 to the outer side in the X-axis direction (judged from the center of the bobbin 20 / the same applies hereinafter) The upper surface is substantially flush with the bottom surface of the through hole 29. Further, the width of the first pedestal 22 in the Y-axis direction is larger than the width of the first collar portion 24 in the Y-axis direction, and protrudes from both end surfaces of the collar portion 24 in the Y-axis direction by a predetermined width.

  It is preferable that the predetermined width of the first pedestal 22 protruding from both end surfaces in the Y-axis direction of the collar portion 24 along the Y-axis is substantially the same as the width in the Y-axis direction of the side leg 48 of the core 401. The side leg portion 48 is placed on the portion of the predetermined width which is ejected. Further, a length X1 where the tip 22a of the first pedestal 22 protrudes from the outer end face of the collar 24 along the X-axis direction is larger than the width of the base 44 of the core 401 in the X-axis direction. The length X1 is such that the distance X2 between the external connection portion 362 (352) of the secondary terminal 36 (35) shown in FIG. 1B and the first flat lead portion 313 (312) to be the primary terminal is a predetermined length or more It is decided to become This distance X2 is preferably 5 mm or more.

  The second pedestal 23 extends from the lower side in the Z-axis direction of the second collar portion 26 to the outer side in the X-axis direction opposite to the first pedestal 22, and the Z-axis upper surface of the second pedestal 23 penetrates It is substantially flush with the bottom of the hole 29. The width of the second pedestal 23 in the Y-axis direction is larger than the width of the second flange 26 in the Y-axis direction, and protrudes from the both end surfaces of the flange 26 in the Y-axis direction by a predetermined width.

  It is preferable that the predetermined width of the second pedestal 23 protruding from both end surfaces in the Y-axis direction of the collar 26 along the Y-axis is substantially the same as the width in the Y-axis direction of the side leg 48 of the core 401. The side leg portion 48 is placed on the portion of the predetermined width which is ejected. Further, the length by which the end portion 23a of the second pedestal 23 protrudes from the outer end face of the collar portion 26 along the X-axis direction is about the same as the width of the base portion 44 of the core 401 in the X-axis direction The base portion 44 is placed on the portion.

  As shown in FIG. 3A, in the present embodiment, the wire 34 is wound around the outer periphery of the winding core 28 located between the first collar 24 and the second collar 26. A secondary coil is formed. The wire 34 may be composed of a single wire or may be composed of a stranded wire such as a litz wire. The wire diameter of the wire 34 is not particularly limited, but is preferably in the range of 1.0 to 4.0 mm. The wire 34 is composed of a conductive wire such as a metal wire, but may be an insulation coated wire. The number of turns (turns) of the wire 34 is not particularly limited, and is, for example, several tens to several hundreds of turns of the number of turns of the primary coil.

  Further, the first flat coil portion (primary coil) 311 of the first flat plate conductor 31 is embedded in the first flange portion 24, and the second flange portion 26 includes the second flat plate conductor 32. A flat coil portion (primary coil) 321 is embedded. As shown in FIG. 4, the first flat coil portion 311 of the first flat conductor 31 has a ring plate shape of about one turn (more specifically, about 3⁄4 turn), and that part is As shown to FIG. 3A, it embeds inside the 1st collar part 24. As shown in FIG. Further, as shown in FIG. 4, the second flat coil portion 321 of the second flat conductor 32 has a ring plate shape of about one turn (more specifically, about 3⁄4 turn), and the portion thereof Are embedded in the inside of the second collar 24 as shown in FIG. 3A.

  As shown in FIG. 3A, the coil portions 311 and 321 of the flat conductors 31 and 32 are insert-molded together with the bobbin 20 in order to embed the flat coil portions 311 and 321 in the insides of the collar portions 24 and 26. Further, in order to position the coil portions 311 and 321 of the flat conductors 31 and 32 at predetermined positions inside the flange portions 24 and 26 of the bobbin 20, Z inside the flange portions 24 and 26 of the bobbin 20 An axially extending die cutting hole 241, 261 is formed.

  In addition, bent pieces 314 and 324 are integrally formed at the upper ends in the Z-axis direction of the coil portions 311 and 321, respectively. The bending pieces 314 and 324 are bent from the upper end in the Z-axis direction of the coil portions 311 and 321 parallel to the ZY plane to a plane parallel to the XY plane. A positioning pin in a mold (not shown) abuts on the lower surface in the Z-axis direction of each of the bent pieces 314 and 324, the flat conductors 31 and 32 are positioned in the inside of the mold, and the bobbin 20 is formed. After the bobbin 20 is formed, the positioning pins are pulled out along the die cutting holes 241 and 261, and the die cutting holes 241 and 261 remain in the bobbin 20. In addition, the coil portions 1 and 321 of the flat conductors 31 and 32 are positioned inside the respective collar portions 24 and 26 to be integrated. In addition, although the die-cutting holes 241 and 261 are formed in the position which avoided the through-hole 29 of the bobbin 20, the position is not specifically limited.

  As shown in FIG. 4, first flat lead portions 312 and 313 are formed on both ends of the first flat coil portion 311, respectively. As shown in FIG. 1B, each first flat plate lead portion 312, 313 protrudes outward from the bottom surface 221 of the first pedestal 23 of the bobbin 20 downward in the Z-axis direction, and is bent inwardly toward the wire coil portion 341. is there. Further, as shown in FIG. 4, second flat plate lead portions 322 and 323 are formed on both ends of the second flat coil portion 321, respectively. As shown in FIG. 1B, the respective second flat plate lead portions 322 and 323 protrude outward from the bottom surface 231 of the second pedestal 23 of the bobbin 20 downward in the Z-axis direction, and are bent inward toward the wire coil portion 341 is there. In addition, as shown to FIG. 3B, the flat plate coil part 311 is integrated with the inside of the bobbin 20 so that about 3/4 circumference of the through-hole 29 may be enclosed. The flat coil portion 321 shown in FIG. 4 is also similar to the flat coil portion 311.

  As shown in FIG. 5, the pair of second terminals 35 and 36 respectively include wire connection portions 351 and 361 protruding in the X-axis direction, and external connection portions 352 and 362 protruding in opposite directions to each other in the Y-axis direction. Have. Between the wire connection portions 351 and 361 and the external connection portions 352 and 362 in each of the terminals 35 and 36, an intermediate portion bent in a step shape in the Z-axis direction is integrally formed.

  The step-like intermediate portions of the terminals 35 and 36 are embedded in the tip 22 a of the first pedestal 22 in the X-axis direction, as shown in FIG. 1A, and the wire connecting portions 351 of the terminals 35 and 36 are provided. , 361 project outward from the tip 22a in the X-axis direction. In addition, the external connection portions 352 and 362 of the respective terminals protrude from the bottom surface 221 in the Z-axis direction at the end portion 22a of the first pedestal 22 and are bent outward in the Y-axis direction. Each of the terminals 35 and 36 is also integrated with the first pedestal 22 of the bobbin 20 by insert molding at the time of molding of the bobbin 20 in the same manner as the flat conductors 31 and 32 shown in FIG. 3A.

  In the present embodiment, the flat conductors 31, 32 are made of a conductive plate such as a metal such as copper, aluminum, tin, nickel, or an alloy thereof. Although the thickness of the flat conductors 31 and 32 is not particularly limited, it is preferably 0.3 to 0.8 mm. The surfaces of the flat conductors 31 and 32, particularly the surfaces of the lead portions 312, 313, 322 and 323, are plated or roughened for the purpose of improving the adhesion with a bonding member such as solder. It may be done. The materials of the terminals 35 and 36 are the same as those of the flat conductors 31 and 32.

  As shown in FIG. 1C, a pair of wire leads 342 and 343 which are both ends of the wire 34 pass through the lead passage 223 formed on the bottom surface 221 of the first pedestal 22 and respectively a pair of secondary terminals 35, It is tangled and connected to the 36 wire connection parts 351 and 361. The wire connection portions 351 and 361 in which the wire lead portions 342 and 343 are respectively wound may be joined by soldering, by laser, or by other joining means such as resistance welding.

  The lead passage 223 formed on the bottom surface 221 of the first pedestal 22 is between the pair of lead projections 222 linearly extending in the X-axis direction at the central portion of the bottom surface 221 of the first pedestal 22 in the Y-axis direction. It is formed in the shape of a groove. The lead convex portion 222 can improve insulation by securing a creeping distance between the pair of wire leads 342 and 343 passing through the lead passage 223 and the flat plate lead portions 312 and 313 to be the first terminals. it can. Similarly, the lead convex portion 222 secures a creeping distance between the pair of wire leads 342 and 343 passing through the lead passage 223 and the external connection portions 352 and 362 of the second terminals 35 and 36. Insulation can be improved.

  In the middle of the lead projections 222 and 222 in the X-axis direction, terminal projections 225 and 225 extending in the Y-axis direction are integrally formed so as to intersect the respective lead projections 222 and 222. The terminal projections 225 and 225 are disconnected in the lead passage 223 so as not to disturb the passage of the wire leads 342 and 343. The terminal projections 225, 225 are formed between the first flat plate lead portions 312, 313 as primary terminals and the external connection portions 352, 362 of the secondary terminals 35, 36, and secure the creepage distance between them. Improve insulation.

  Also, on the bottom surface 221 of the first pedestal 22 located between the wire coil portion 341 and the first flat plate lead portions 312 and 313, the coil convex portions 224 and 224 intersect the lead convex portions 222 and 222. Integrated and formed. The coil projections 224 and 224 extending in the Y-axis direction are interrupted at the lead passage 223 so as not to disturb the passage of the wire leads 342 and 343. The coil convex portions 224, 224 are formed between the first flat plate lead portions 312, 313 as the primary terminals and the wire coil portion 341, secure the creepage distance of these and improve the insulation.

  Further, on the bottom surface 231 of the second pedestal 23 located between the wire coil portion 341 and the second flat plate lead portions 322 and 323, a coil convex portion 234 is formed along the Y-axis direction. The coil convex portion 234 extending in the Y-axis direction is formed between the first flat plate lead portions 322 and 323 as the primary terminals and the wire coil portion 341, secures a creeping distance therebetween, and improves the insulation.

  As shown in FIG. 1B, the height at which each protrusion 222, 225, 224, 234 protrudes downward from the bottom surface 221, 231 to the Z axis is flat lead portion 312, 313, 322, 323 and external connection portion 352, The height 362 is set to be lower than the height projecting from the bottom surfaces 221 and 231. These flat plate lead portions 312, 313, 322, 323 and external connection portions 352, 362 can be connected to the mounting surface of the external substrate (not shown) without being interrupted by the convex portions 222, 225, 224, 234. It is done like that.

  As shown in FIGS. 3A and 3B, the groove depth in the Z-axis direction of the lead passage 223 is larger than the protruding height from the bottom surface 221, 231 of each convex portion 222, 225, 224, 234. This is to improve the insulation between the wire leads 342 and 343 passing through the lead passage 223 and the first flat plate lead portions 312 and 313 as primary terminals.

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

  The transformer 10 according to the present embodiment is manufactured by winding the wire 34 around the core portion 28 of the bobbin 20 while assembling the respective members shown in FIG. Below, an example of the manufacturing method of the transformer 10 is demonstrated using FIG. 2 etc. FIG. In manufacturing the transformer 10, first, the bobbin 20 is prepared.

  As described above, the flat coil portions 311 and 321 of the flat conductors 31 and 32 are integrally formed on the bobbin 20 by insert molding so that the flat coil portions 311 and 321 are embedded in the insides of the collar portions 24 and 26. In addition, it is integrated with the end portion 22a of the first pedestal 22 of the bobbin 20 by insert molding so that the intermediate portion of the terminals 35 and 36 is embedded.

  Next, the wire 34 is wound around the outer periphery of the winding core portion 28 of the bobbin 20 shown in FIG. 3A to form a wire coil portion 341. The wire 34 is not particularly limited, but a litz wire or the like is preferably used. Further, as shown in FIG. 1C, the wire leads 342 and 343 which are both ends of the wire 34 are tangled in the wire connection portions 351 and 361 of the pair of terminals 35 and 36 through the lead passage 223, respectively. For example, it is connected by soldering.

  After the winding operation, the flat lead portions 312, 313, 323, 322 of the flat conductors 31, 32 and the external connection portions 352, 362 of the secondary terminals 35, 36 are bent as needed. The flat plate lead portion and the external connection portion may be bent in advance. This is because it does not interfere with the winding operation of the wire 34.

  Next, as shown in FIG. 2, the cores 401 and 402 are attached from both directions in the X-axis direction. That is, the tips of the side legs 48, 48 are joined together with a gap between the tips of the middle legs 46, 46 of the cores 401, 402. The gap may be zero. After the core portion 40 composed of the cores 401 and 402 is attached to the bobbin 20, an adhesive is applied between the base portion 44 of the cores 401 and 402 and the outer end surface of the flange portions 24 and 26 in the X-axis direction. It is also good.

  The top plate 50 is attached to the bobbin 20 so that the Z-axis upper surface of the 1st collar part 24 and the 2nd collar part 26 is bridged before and behind that. The top plate 50 includes a top plate main body 52 that entirely covers the upper surface of the bobbin main body 21 in the Z-axis direction, and locking pieces 54 provided at both ends in the X-axis direction. A fitting hole is formed in the locking piece 54, and a fitting projection formed in the upper part in the Z-axis direction of the outer end face in the X-axis direction of the flanges 24 and 26 is fitted in the fitting hole The top plate 50 is attached to the top of the bobbin 20. Although it does not specifically limit as a material which comprises the top plate 50, The synthetic resin similar to the bobbin 20, or a ceramic etc. are illustrated.

  In the transformer 10 according to the present embodiment, as shown in FIG. 3A, a wire coil portion 341 as a secondary coil is disposed between flat plate coil portions 311 and 321 as a pair of primary coils. Therefore, the coupling between the primary coil and the secondary coil is improved. In addition, the primary coil is separated into two as flat plate coil portions 311 and 321, and by connecting these coil portions 311 and 321 with an external circuit, the current that can be flowed in total to the primary coil can be increased. Contributes to the increase of current. In addition, the insulation distance can be secured by arranging the secondary terminals 35 and 36 of the wire coil portion 341 as the secondary coil on the outside in the X axis direction of the first flat plate coil portion 311 as the primary coil. Furthermore, miniaturization of the transformer can also be realized.

  In addition, the primary coil has flat coil portions 311 and 321 and a pair of flat lead portions 312, 313, 322 and 323, and a wire coil portion as a primary coil between flat surfaces of the flat coil portions 311 and 321. 341 is arranged. With such a configuration, it is possible to flow a larger current as compared with the case where the primary coil is configured by a wire, and the coupling between the primary coil and the secondary coil is also improved.

  The flat coil portions 311 and 321 are integrated into the inside of the collar portions 24 and 26 positioned on both sides of the winding core portion 28 in the X-axis direction. By integrating the flat coil portions 311 and 321 into the inside of the collar portions 24 and 26 of the bobbin 20 by insert molding or the like, the bobbin 20 can be easily molded, and the transformer 10 can be miniaturized.

  Further, since the flat plate lead portions 312, 313, 322, 323 protrude outward from the bottom surfaces 221, 231 on the mounting surface side of the flange portions 24, 26, respectively, to form the primary terminals, the formation of the primary terminals is easy. .

  Furthermore, the first pedestal 22 is integrated with one of the first flanges 22, and the wire leads 342 and 343 are formed on the bottom surface 221 of the mounting side located between the pair of flat plate leads 312 and 313. It passes through the lead passage 223 and is connected to the secondary terminals 35 and 36 respectively. The wire leads 342 and 343 are drawn in the direction of the secondary terminal 35. 36 through the bottom surface 221 on the mounting surface side, so that the insulation between the wire leads 342 and 343 and the magnetic core 40 can be easily secured.

  Furthermore, in the present embodiment, the top plate 50 is attached to the anti-mounting surface (upper surface in the Z-axis direction) opposite to the bottom surfaces 221 and 231 on the mounting surface side of the pair of flanges 24 and 26. . The suction head is attracted to the upper surface of the top plate 50, which facilitates the transport of the transformer. Further, as shown in FIG. 1A, the magnetic core 40 may be fixed together with the bobbin 20 by a belt 70 or the like excellent in thermal conductivity.

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

  For example, in the embodiment described above, the pair of secondary terminals 351 and 361 are attached to the tip of the first pedestal 22 disposed at one end of the bobbin 20 in the X-axis direction. The secondary terminal 351 may be disposed at the tip of the first pedestal 22 and the other secondary terminal 361 may be disposed at the tip of the second pedestal 23 in the X-axis direction. In that case, it is preferable that the second pedestal 23 also protrudes from the bobbin main body 21 of the bobbin 20 in the X-axis direction, similarly to the first pedestal 22. Further, in that case, the lead passage 223, the lead convex portion 222, and the terminal convex portion 225 similar to the back surface 221 of the first pedestal 22 are also formed on the back surface 231 of the second pedestal 23 shown in FIG. Is preferred.

  Moreover, in the embodiment described above, as shown in FIG. 1B, the flat lead portions 312, 313, 322, 323 are bent inward toward the wire coil portion 341, but these flat lead portions 312, 313, 322 , 323 may be bent outward.

  Furthermore, in the embodiment described above, as shown in FIG. 2, the core portion 40 is configured by combining cores 401 and 402 of the same E type, but one core is an E type core and the other core is an I type core Or the like, and may be configured by combining cores of different shapes.

  Furthermore, in the embodiment described above, the primary coil is configured by the coil portions 311 and 321 of the pair of flat conductors 31 and 32, but may be configured by a pair of wire coil portions.

DESCRIPTION OF SYMBOLS 10 ... Transformer 20 ... Bobbin 21 ... Bobbin main body 22 ... 1st base 221 ... Mounting side bottom surface 222 ... Lead convex part 223 ... Lead passage 224 ... Coil convex part 225 ... Terminal convex part 23 ... 2nd base 231 ... Mounting Side bottom surface 234 ... Convex part for coil 24 ... 1st collar part 241 ... Die cut hole 26 ... 2nd collar part 261 ... Die cut hole 28 ... Wind core part 29 ... Through hole 31 for core leg 31 ... 1st flat conductor 311 ... First flat coil section (primary coil)
312, 313 ... 1st flat plate lead (primary terminal)
314 ... bent piece 32 ... second flat plate conductor 321 ... second flat coil section (primary coil)
322, 323 ... 2nd flat plate lead part 324 ... bent piece 34 ... wire 341 ... wire coil part (secondary coil)
342, 343 ... Wire lead 35, 36 ... Secondary terminal 351, 361 ... Wire connection 352, 362 ... External connection 40 ... Magnetic core (core)
401 ... first core 402 ... second core 44 ... base section 46 ... middle leg section 48 ... side leg section 50 ... top board 52 ... top board main body section 54 ... locking piece 60 ... belt

Preferably, each of the primary coils has a flat coil portion and a pair of flat lead portions, and the secondary coil is disposed between flat surfaces of the flat coil portion. With such a configuration, it is possible to flow a larger current as compared with the case where the primary coil is configured by a wire, and the coupling between the primary coil and the secondary coil is also improved.

Preferably, the flat plate lead portion protrudes outward from the bottom surface on the mounting side of the flange portion to form a primary terminal. With such a configuration, the formation of the primary terminal is easy.

Preferably, the first pedestal is integrated with any of the ridges,
The wire lead portions are respectively connected to the secondary terminals through the mounting-side bottom surface positioned between the pair of flat plate lead portions. Since the wire lead portion is drawn in the direction of the secondary terminal through the bottom surface on the mounting side , it is easy to ensure the insulation between the wire lead portion and the magnetic core. In addition, it is easy to ensure insulation between the wire lead portion and the primary terminal.

Preferably, a terminal protrusion is formed on the mounting-side bottom surface of the first pedestal to improve insulation between the primary terminal and the secondary terminal. With this configuration, the insulation between the primary terminal and the secondary terminal can be improved.

Preferably, a top plate is attached to the opposite mounting surface located on the opposite side to the mounting side bottom surface of the pair of ridges. The suction head is attracted to the upper surface of the top plate, which facilitates the transport of the transformer.

Further, since the flat plate lead portions 312, 313, 322, 323 protrude outward from the bottom surfaces 221, 231 on the mounting side of the flange portions 24, 26, respectively, to form the primary terminals, the formation of the primary terminals is easy.

Furthermore, the first pedestal 22 is integrated with one of the first flanges 22, and the wire leads 342 and 343 are formed on the bottom surface 221 of the mounting side located between the pair of flat plate leads 312 and 313. It passes through the lead passage 223 and is connected to the secondary terminals 35 and 36 respectively. The wire leads 342 and 343 are drawn in the direction of the secondary terminal 35. 36 through the bottom surface 221 on the mounting side , so that the insulation between the wire leads 342 and 343 and the magnetic core 40 can be easily secured.

Furthermore, in the present embodiment, the top plate 50 is attached to the anti-mounting surface (upper surface in the Z-axis direction) located on the opposite side to the bottom surfaces 221 and 231 on the mounting side of the pair of flanges 24 and 26. The suction head is attracted to the upper surface of the top plate 50, which facilitates the transport of the transformer. Further, as shown in FIG. 1A, the magnetic core 40 may be fixed together with the bobbin 20 by a belt 70 or the like excellent in thermal conductivity.

Claims (10)

A pair of primary coils,
A bobbin having a winding core portion in which a secondary coil is disposed between the primary coils;
A transformer having a pair of secondary terminals to which wire lead portions which are both ends of a wire constituting the secondary coil are respectively connected,
An axially extending direction of the bobbin such that at least one of the secondary terminals is disposed outside the primary coil along an axial direction of the winding core portion; Transformer attached to the tip of 1 pedestal. Each of the primary coils has a flat coil portion and a pair of flat lead portions,
The transformer according to claim 1, wherein the primary coil is disposed between flat surfaces of the flat coil portion.   The transformer according to claim 2, wherein each of the flat plate coil portions is integrated in the inside of a collar portion positioned on both sides in the axial direction of the winding core portion.   The transformer according to claim 3, wherein the flat plate lead portion protrudes outward from the bottom surface on the mounting surface side of the flange portion to form a primary terminal. The first pedestal is integrated with any of the buttocks,
5. The transformer according to claim 4, wherein the wire lead portion is connected to the secondary terminal through the bottom surface on the mounting side located between the pair of flat plate lead portions.   The transformer according to claim 5, wherein a lead convex portion for improving the insulation between the flat plate lead portion and the wire lead portion is formed on the mounting side bottom surface through which the wire lead portion passes.   The transformer according to any one of claims 4 to 6, wherein a coil convex portion for improving the insulation between the secondary coil and the primary terminal is formed on the bottom surface on the mounting side.   The transformer according to any one of claims 4 to 7, wherein a terminal convex portion for improving insulation between the primary terminal and the secondary terminal is formed on the bottom surface of the mounting surface of the first pedestal.   The transformer according to any one of claims 3 to 8, wherein a top plate is attached to an opposite mounting surface located on the opposite side to the mounting surface side bottom surface of the pair of ridges. The bobbin is formed with a through hole passing through the axis of the primary coil and the axis of the pair of secondary coils,
The transformer according to any one of claims 1 to 9, wherein a middle leg of a magnetic core is inserted into the through hole.

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