JP2013229353A - Electromagnetic inductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic inductor having a high withstand voltage characteristic by securing stable insulation distance while using a filler.SOLUTION: An electromagnetic inductor 1 includes: a body 7 having an insulative bobbin 2, a core 3 inserted through an insertion hole of a cylindrical part 11 of the bobbin 2, a first coil 4 arranged outside the cylindrical part of the bobbin, a second coil 5 overlapped outside the first coil, and a spacer 6 arranged between both the coils; and first and second terminals connected to both the coils. A through opening 15 is formed in at least two mutually facing parts in the cylindrical part 11, the spacer 6 is composed of a plurality of pillar parts extending in an axial direction X arranged at intervals in a circumferential direction, and at least the bobbin 2, the core 3, and the first and second coils 4, 5 are embedded in the filler 20.

Description

  The present invention relates to an electromagnetic inductor in which each part of a main body in which a coil is wound around a bobbin attached to a core is embedded in a filler.

  In general, an electromagnetic inductor such as a transformer has a cylindrical bobbin, a core inserted through an insertion hole of the bobbin, and first and second coils (primary winding and Secondary winding) and pin terminals connected to these coils. In this case, the core and both coils are insulated by a bobbin made of insulating resin, and the two coils are insulated by, for example, winding an insulating tape around one coil.

  Conventionally, in order to prevent insulation failure due to moisture in the transformer, each part of the main body in which the first and second coils are wound around the bobbin attached to the core is housed in a case, and the like. A transformer embedded in a filler is also known (for example, Patent Document 1). In this case, bubbles were removed from each part and the filling resin by vacuum defoaming or heating during the defoaming step after assembling the transformer.

  FIG. 5 shows a partial side view of a conventional resin-filled transformer. The transformer 51 includes a cylindrical resin bobbin 52, a core 53 inserted through the insertion hole 62 of the bobbin 52, and first and second coils 54 and 55 wound around the outside of the bobbin 52. And a case 60 for housing the main body. The coils 54 and 55 are insulated by laminating an insulating tape 65 such as a polyester tape with an adhesive. The case 60 is filled with a filler 70 such as an epoxy resin having a low dielectric constant.

JP 2005-109159 A

  However, in conventional resin-filled transformers, a gap between a coil having a circular cross section and a flat insulating tape around which the coil is wound, a gap between a core and a bobbin, and between laminated insulating tapes or in an adhesive In addition, there is a problem that the filling resin is difficult to enter into each part, and bubbles are caught in each part at the time of defoaming. In addition, when the number of laminated insulating tapes is increased in order to ensure the insulation distance between the coils, more bubbles remain between the laminated layers.

  In other words, conventional resin-filled transformers have a problem that bubbles are difficult to escape structurally at each part of the bobbin, core, coil, and insulating tape during defoaming. Corona due to voltage is generated, the life of the transformer is deteriorated, and the withstand voltage characteristic is lowered. In addition, since the resin filler and the insulating tape around which the coil is wound have different dielectric constants, corona due to charge bias is likely to occur at this portion. Furthermore, since the insulating tape and the adhesive use a flexible material for winding the coil, securing the insulation distance between the coils may become unstable.

  An object of the present invention is to provide an electromagnetic inductor that ensures a stable insulation distance and has high withstand voltage characteristics while using a filler.

  In order to achieve the above object, an electromagnetic inductor according to one configuration of the present invention includes an insulating bobbin, a core inserted through an insertion hole of a cylindrical portion of the bobbin, and an outer side of the cylindrical portion of the bobbin. A main body having a first coil formed, a second coil overlaid on the outside, a spacer disposed between the two coils, and first and second terminals connected to the two coils. A through hole is formed in at least two opposing portions of the cylindrical portion, and the spacer has a plurality of axially extending column portions arranged at intervals in the circumferential direction, and includes at least the bobbin, core, First and second coils are embedded in the filler.

  According to this configuration, the spacers disposed between the first and second coils are arranged with a plurality of pillars extending in the axial direction at intervals in the circumferential direction, so that an insulation distance between the two coils is ensured. In addition, no insulating tape is required. In addition, since the insulating tape is not interposed between the two coils and the through hole is formed in the cylindrical portion of the bobbin, the air bubbles easily escape from the bobbin, the core, and the coil in the filling material, and Generation | occurrence | production can be suppressed and a withstand voltage characteristic can fully be ensured. Thereby, while using a filler, a stable insulation distance can be secured and an electromagnetic inductor having high withstand voltage characteristics can be obtained.

  In the present invention, an upper case is provided, the main body is accommodated in the case, one of the first and second terminals protrudes from the filler, and the other protrudes downward from the bottom wall of the case. It is preferable. In this case, the main body is stably embedded in the filler in the case.

  Preferably, the through hole of the cylindrical part of the bobbin is formed in the upper and lower parts. Therefore, it is easy for bubbles to escape from the core and bobbin in the vertical direction. The core has a square shape having a pair of leg portions and a connecting portion for connecting both leg portions, and each leg portion may be inserted into an insertion hole of a cylindrical portion of the bobbin.

  In addition, the spacer may include two opposing column portions and a connecting side portion that connects both the column portions. In this case, the insulation distance between the two coils can be secured stably with a simple structure.

  Preferably, the spacer is provided to be slidable in a direction orthogonal to the axial direction of the cylindrical portion of the bobbin. Therefore, a desired insulation distance can be set between both coils.

  The present invention eliminates the need for an insulating tape while providing an insulating distance between the coils by providing a spacer between the coils, and by providing a through-hole in the cylindrical portion of the bobbin together with bubbles that cause corona generation. Has a structure that is easily removed. Thereby, while using a filler, a stable insulation distance can be ensured and a withstand voltage characteristic can be improved.

It is a perspective view which shows an electromagnetic inductor like the transformer concerning one Embodiment of this invention. It is an exploded view of the electromagnetic inductor before the case storage of FIG. (A) is the perspective view which shows the electromagnetic inductor before case accommodation seen from upper direction, (B) is the perspective view seen from the lower part. It is a perspective view which shows the modification of a spacer. It is a partial side view which shows the conventional resin filling transformer.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an electromagnetic inductor 1 such as a transformer according to an embodiment of the present invention. As shown in FIG. 1, an electromagnetic inductor 1 such as a reactor or a transformer includes an insulating bobbin 2, a core 3 inserted through an insertion hole 12 (FIG. 2) of a cylindrical portion 11 of the bobbin 2, and the bobbin For example, a first coil 4 such as a secondary winding disposed outside the cylindrical portion 11, a second coil 5 such as a primary winding superimposed on the outside, and both windings 4 5 includes a main body 7 having a spacer 6 disposed between the first and second terminals 8 and 9 (FIG. 3) connected to the windings 4 and 5.

  FIG. 2 is an exploded view of the transformer 1 before housing the case. As shown in FIG. 2, the bobbin 2 includes a rectangular tube-shaped tube portion 11 that is a winding frame portion, and a flange portion 13 formed at both ends in the axial direction X of the tube portion 11. The first and second terminals 8 and 9 are erected in the Z direction, for example, the vertical direction (FIG. 3). The bobbin 2 is made of an insulating resin such as polyethylene terephthalate (PET) or phenol (PF).

  As shown in FIG. 1, the transformer 1 includes a case 10 that opens upward. The main body 7 is accommodated in the case 10 and a filler 20 is filled therein. At least the bobbin 2, the core 3, and the first and second coils (secondary winding and primary winding) 4 and 5 in the main body 7 are embedded in the filler 20. As the filler 20, for example, a gel-like silicon resin or an epoxy resin is used.

  One of the first and second terminals 8 and 9 protrudes upward from the filler 20 whose upper surface is exposed, and the other protrudes downward from the bottom wall of the case 10. The case 10 is made of, for example, polycarbonate (PC) or polyethylene terephthalate (PET). In this example, the first terminal 8 to which the lead wire 4a of the secondary winding 4 is connected protrudes upward from the filler 20, and the second terminal 9 to which the primary winding 5 is connected (FIG. 3 (B )) Protrudes downward from the bottom wall of the case 10. Further, the number of turns of the secondary winding 4 and the primary winding 5 is relatively small, and the primary winding 5 having a smaller number of turns (eg, number of turns 3) is provided outside the secondary winding 4. It is wound.

  The core 3 inserted into the insertion hole 12 of the bobbin 2 and the secondary winding and the primary windings 4 and 5 are insulated by the cylindrical portion 11 and the filling resin 20 which are the bobbin 2 winding frame portions. . As shown in FIG. 2, through-holes 15 are formed in a portion of the cylindrical portion 11 facing each other in the Z direction orthogonal to the axial direction X, in this example, the upper and lower portions. As a result, as shown in FIG. 1, the upper and lower portions of the core 3 are exposed by the through-hole 15 of the bobbin 2, and bubbles easily escape from the periphery of the core 3 and the bobbin 2 in the vertical direction Z. In this example, there are provided through-holes penetrating the upper and lower surfaces of the cylindrical portion 11 in the Z direction, but further through-holes penetrating the cylindrical portion 11 in the Y direction perpendicular to the axial direction X. May be provided so as to penetrate all four surfaces of the cylindrical portion 11. In this case, the cylindrical portion 11 of the bobbin 2 has only four columnar outer frames, and air bubbles easily escape not only in the vertical direction Z but also in the horizontal direction Y.

  As shown in FIG. 2, in the transformer 1, two bobbins 2 and 2 having the same shape and size are juxtaposed in the Y direction, and the core 3 is a leg portion of a pair of U-shaped core pieces 3a and 3a facing each other. 21 and 21 are inserted into the insertion holes 12 of the cylindrical portions 11 of the two bobbins 2, and the tips of the leg portions 21 and 21 are in contact with or close to each other. It is formed in a square shape having a pair of leg portions 21, 21 inserted through the holes 12, 12 and a connecting portion 22 that connects both the leg portions 21, 21.

  An advancing portion 16 and a retracting portion 17 are provided adjacent to each other in the axial direction X (left and right) at the front and rear ends in the Y direction of each collar portion 13 in the bobbin 2. For example, an advancing portion 16a and a retreating portion 17a are formed on the left and right ends of the Y direction, and a retreating portion 17b and an advancing portion 16b are formed on the left and right of the rear end. The two bobbins 2 and 2 are assembled by fitting the rearwardly retreating part 17b and the leading end advancing part 16a, and fitting the rearward advancing part 16b and the leading end retreating part 17a.

  FIG. 3A is a perspective view showing the electromagnetic inductor before housing the case as seen from above, and FIG. 3B is its perspective view as seen from below. As shown in FIG. 3A, the spacer 6 disposed between the secondary winding 4 of FIG. 1 and the primary winding 5 outside thereof has a plurality of, for example, two upper and lower column portions 24 extending in the axial direction X. , 24 are arranged at intervals in the circumferential direction of the bobbin 2, and have a square shape having two column portions 24, 24 facing each other and connecting side portions 25, 25 connecting both the column portions 24, 24. Shape. The spacer 6 is made of, for example, polyethylene terephthalate (PET).

  The rectangular spacer 6 is provided so that the column parts 24, 24 extend in the axial direction X of the cylindrical part 11 of the bobbin 2, and the coupling side parts 25, 25 are orthogonal to the axial direction X of the cylindrical part 11. It extends to Z. A total of two spacers 6, 6 are arranged on each side in the Y direction of the cylindrical portion 11 of the bobbin 2. The spacer 6 is slidable in a direction Z perpendicular to the axial direction X of the cylindrical portion 11 of the bobbin 2. In this example, the spacer 6 can move up and down along the mounting grooves 18, 18 provided in pairs on the inner surfaces of both collar portions 13 and extending in the Z direction. Since the secondary winding 4 and the primary winding 5 can be set to an arbitrary winding height by sliding the spacer 6, a desired insulation distance can be easily obtained between the windings 4 and 5.

  In this way, the transformer 1 secures an insulation distance between the windings 4 and 5 by providing the spacer 6 between the secondary winding and the primary winding (first and second coils) 4 and 5. However, the body comprising the bobbin 2, the core 3 and the two windings 4 and 5 in the filler 20 within the case 10 by providing the through-hole 15 in the cylindrical portion 11 of the bobbin 2 together with the insulating tape is unnecessary. 7 has a structure in which bubbles that cause corona are easily removed.

  FIG. 4 shows a modification of the spacer. In this example, four groove portions 27 extending in the radial direction, that is, in the oblique direction S on the YZ plane, are provided on the inner walls 13a of both collar portions 13 of the bobbin 2A. The four rod-shaped spacers 26 extending in the axial direction X are slidable in the oblique direction S. Similarly, the windings 4 and 5 can be set to arbitrary winding heights by sliding the spacer 26, so that a desired insulation distance can be easily obtained. In addition, when two spacers 26 are provided in each groove 27, for example, three layers of the primary winding, the secondary winding, and the primary winding are sequentially incremented by two spacers 26 and 26, respectively. Insulation between the secondary winding and the secondary winding and between the secondary winding and the primary winding is possible, and by increasing the number of spacers 26, a laminated structure of three or more windings is possible.

  Thus, in the electromagnetic inductor according to the present invention, the plurality of column portions in which the spacer disposed between the first and second coils extends in the axial direction are disposed at intervals in the circumferential direction of the bobbin. Insulation distance between both coils is ensured, and no insulating tape is required. In addition, since the insulating tape is not interposed between the two coils and the through-hole is formed in the cylindrical portion of the bobbin, it is easy for the bobbin, the core, and the coil in the filler to escape and the bubbles on the surface of the insulator The withstand voltage characteristics can be sufficiently secured by suppressing the generation of corona. Thereby, while using a filler, a stable insulation distance can be secured and an electromagnetic inductor having high withstand voltage characteristics can be obtained.

  In addition, although the electromagnetic inductor of this embodiment is applied to a transformer, it is not limited to this at all, and may be applied to, for example, an inductor or an in-vehicle igniter.

  Moreover, in this embodiment, although the core is made into a square shape, it is not limited to this at all, and may be an O shape or an EE shape.

  In this embodiment, the main body is housed in the case, but the case may be omitted if the resin filler after filling can maintain a stable shape. In addition, the spacer may be omitted when the insulation distance between the two coils can be held by the filler.

1: Electromagnetic inductor (transformer)
2: Bobbin 3: Core 4: First coil (secondary winding)
5: Second coil (primary winding)
6: Spacer 7: Body 8: First terminal 9: Second terminal 10: Case 11: Tube portion 12: Insertion hole 15: Through hole 20: Filler 21: Leg portion 22: Connection portion 24: Column portion 25 : Join side X: Axial direction

Claims (6)

An insulative bobbin, a core inserted through an insertion hole of the cylindrical part of the bobbin, a first coil disposed outside the cylindrical part of the bobbin, and a second coil superimposed on the outside; A main body having a spacer disposed between the two coils, and first and second terminals connected to the two coils,
A through-hole is formed in at least two opposite portions of the cylindrical portion,
The spacer is arranged with a plurality of pillars extending in the axial direction at intervals in the circumferential direction,
An electromagnetic inductor in which at least the bobbin, core, and first and second coils are embedded in a filler. In claim 1,
And a case opened upward, in which the main body is housed, one of the first and second terminals protrudes from the filler, and the other protrudes downward from the bottom wall of the case. Inductor. In claim 2,
The electromagnetic induction device in which the through-hole of the said cylinder part is formed in the up-and-down site | part. In any one of Claim 1 to 3,
The said core is a rectangular shape which has a pair of leg part and the connection part which connects both leg parts, and each leg part is penetrated by the penetration hole of the cylinder part of the said bobbin. In any one of Claims 1-4,
The said spacer is an electromagnetic inductor which has two said pillar parts which oppose each other, and the joint side part which connects both pillar parts. In any one of Claim 1 to 5,
The said spacer is an electromagnetic inductor provided so that the slide to the direction orthogonal to the axial direction of the cylinder part of the said bobbin is possible.

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