JP5799687B2 - Trance - Google Patents

Description

  The present invention relates to a transformer that can secure a desired creepage distance between coils and between a coil and a core and can also prevent unwinding of the coil.

  For example, in a transformer with a large current specification, such as an in-vehicle transformer, a coil in which a winding having a large diameter of 1.0 mφ or more is wound is often used in order to reduce the resistance value. Various measures are taken to secure a predetermined creepage distance between the coils or between the coil and the core.

7 to 9 show a conventional transformer of this type, and reference numeral 1 in the drawing is a cylindrical bobbin.
The bobbin 1 is divided into two winding portions in the axial direction by integrally forming a rectangular plate-like partition plate 2 at both ends and an intermediate portion, and one of the winding portions is primary. The coil 3 is wound, and the secondary coil 4 is wound around the other winding portion.

  Here, both end portions 3 a of the primary coil 3 are drawn out to the side 2 a side of the partition plate 2 so as to be parallel to each other, and both end portions 4 a of the secondary coil 4 are both end portions of the primary coil 3. Similarly, the other side 2b of the partition plate 2 that is 180 ° opposite to 3a is drawn out in parallel with each other.

  Further, the primary coil 3 and the secondary coil 4 are provided on the side 2c side adjacent to the sides 2a and 2b of the partition plate 2 from which both ends 3a and 4a of the primary and secondary coils 3 and 4 are drawn. An external appearance substantially rectangular flat-plate-shaped insulating cover 5 covering from the outside is arranged. A ferrite core 6 is provided outside the bobbin 1 and the insulating cover 5.

  The ferrite core 6 is formed as a whole in a Japanese character in a front view by a pair of split cores 7 and 7 having an E shape in a front view. Each divided core 7 includes a flat plate portion 8, a substantially flat side wall portion 9 suspended from both ends in the longitudinal direction of the flat plate portion 8, and a circle erected at the central portion between the side wall portions 9. The columnar middle leg 10 is integrally formed.

  In the pair of cores 7, the flat plate portion 8 is disposed on the side of the partition plate 2 at both ends of the bobbin 1, and the side wall portion 9 covers the insulating cover 5 with the middle leg 10 inserted into the central opening of the bobbin 1. The tape 6a is wound and integrated with the primary coil 3 and the secondary coil 4 so as to be opposed to the primary coil 3 and the secondary coil 4 so as to be in contact with each other to form a closed magnetic circuit. A ferrite core 6 is configured.

  According to the transformer having the above configuration, as shown in FIG. 9, the primary coil 3 and the secondary coil 4 are partitioned by the central partition plate 2, and the primary coil 3, the secondary coil 4, and the ferrite core 6. Since the insulating cover 5 is interposed between the side wall portion 9 and the primary coil 3 and the secondary coil 4, not only between the primary and secondary coils 3 and 4 and the ferrite core 6. In contrast, a predetermined creepage distance can be secured.

  By the way, in such a transformer, since the elastic coefficient of the windings constituting the primary and secondary coils 3 and 4 is high, the winding is wound around the bobbin 1 at the time of manufacture, and the primary coil 3 and When the secondary coil 4 is formed, rewinding occurs due to the springback, the winding diameter of the primary coil 3 or the secondary coil 4 is increased, and the creeping distance is shortened, or the primary coil 3 or 2 The positional accuracy of the end portions 3a and 4a drawn out from the next coil 4 is deteriorated, resulting in inconvenience such as support for connection to the substrate and the like.

  Therefore, when manufacturing this type of transformer in the past, after applying the windings of the primary coil 3 and the secondary coil 4, in order to prevent the winding from being unwound, a jig such as a clip or the like is separately provided. Measures such as temporarily fixing with tape, etc., and assembling other parts such as the core 7 and then removing these jigs and tape, etc., take a lot of trouble for the work, As a result, there is a problem that the manufacturing cost increases.

  The following Patent Document 1 discloses a transformer with a similar large current specification.

JP 2011-082205 A

  The present invention has been made in view of the above circumstances, and can ensure a desired creepage distance between coils and between a coil and a core, and can prevent unwinding of the coil as well as easily and reliably. Another object of the present invention is to provide a transformer that can improve assembly accuracy and reduce manufacturing costs.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a cylindrical shape in which the first winding portion and the second winding portion are formed in the axial direction by a partition plate protruding annularly from the outer peripheral surface. A bobbin, a first coil and a second coil wound around the first and second winding portions of the bobbin, and a core that surrounds the outer periphery of the bobbin to form a closed magnetic circuit. In the transformer, the first coil extends at both ends in the same direction, and the second coil extends at both ends in the same direction, and the first and second coils. Insulating properties having a length dimension in the axial direction of each of the first and second winding portions and covering a range of 1/2 or more in the circumferential direction of the first and second coils. The first and second ring-opening cylindrical holders made of resin are connected to each other from the respective openings. Both ends of yl and is extended outward is characterized in that fitted.

  According to a second aspect of the present invention, in the first aspect of the present invention, the core includes a pair of side wall portions extending in the axial direction with the first and second coils interposed therebetween. In addition, the first and second holders have flanges that protrude from the outer peripheral surface and abut against the partition plate at both ends in the axial direction of each of the first and second holders, at least in a portion facing the side wall of the core. Is formed.

  Furthermore, the invention described in claim 3 is the invention described in claim 1 or 2, wherein both ends defining the opening of the first and second holders extend in parallel outward. A flat plate portion for guiding both end portions of the first and second coils is formed.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the side wall portion of the core surrounds the bobbin and the first and second holders at a central portion of the opposing surface. A cylindrical surface is formed, and on both sides of the cylindrical surface, a flat portion facing the flat plate portion of the first and second holders is formed, and each of the first and second holders has an outer periphery. A detent portion that protrudes from the surface and abuts against the flat portion is formed.

  According to the invention described in any one of claims 1 to 4, the length of each of the first and second coils in the circumferential direction is ½ or more over the entire length in the axial direction of the first and second coils. Since the ring-opening cylindrical first and second holders made of insulating resin covering the range are mounted, the first and second holders allow the first and second coils to be connected to each other and the coil. A predetermined creepage distance can be secured between the core and the core.

  In addition, after the first and second coils are formed by winding the first and second winding portions, the first and second holders are fitted and attached to the outer circumferences of the first and second coils. Thus, rewinding of the winding can be prevented. For this reason, even when the wire diameter of the winding becomes large, the assembly accuracy can be easily and reliably improved without using a jig such as a clip or a tape as in the prior art, and the manufacturing cost is also reduced. It is also possible to achieve a reduction in.

  Moreover, since the first and second holders are formed in an open cylindrical shape, and the ends of the first and second coils are extended outward from the openings, the first and second holders are formed. There is no interference between the second holder and the both-end drawn portions of the first and second coils.

  In particular, according to the invention described in claim 3, the first and second holders extend in parallel to the outer ends of the first and second holders, respectively, and the first and second holders respectively. Since the flat plate portion for guiding both end portions of the coil 2 is formed, even when the winding becomes thick and the lead portion is used as it is as a connection terminal, the positioning accuracy of the both end portions by the flat plate portion is used. It becomes possible to improve.

  Further, according to the invention described in claim 4, the first and second holders having the ring-opening cylindrical shape are formed with the rotation stoppers protruding from the outer peripheral surfaces thereof and coming into contact with the flat portion of the side wall portion of the core. Therefore, after the first and second holders are fitted to the outer circumferences of the first and second coils and the core is disposed around the first and second coils, the non-rotating portion is in contact with the side wall of the core. It is possible to prevent the first and second holders from being misaligned.

1 is an exploded perspective view showing an embodiment of a transformer according to the present invention. It is a top view of the said transformer. It is a front view of the said transformer. It is a side view of the said transformer. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. FIG. 4 is a sectional view taken along line BB in FIG. 3. It is a disassembled perspective view which shows the conventional transformer. FIG. 8 is a plan view of FIG. 7. It is AA sectional view taken on the line of FIG.

1 to 6 show an embodiment of a transformer according to the present invention. The same components as those shown in FIGS. 7 to 9 are denoted by the same reference numerals, and the description thereof is simplified.
As shown in FIGS. 1 to 6, in this transformer, instead of the insulating cover 5 in the transformer shown in FIGS. 7 to 9, the first holder 11 is provided on the outer periphery of the primary coil (first coil) 3. Are provided, and a second holder 12 is provided on the outer periphery of the secondary coil (second coil) 4.

  Each of the first and second holders 11 and 12 is formed in a ring-opening cylindrical shape (cross-sectional C shape) by a thermoplastic resin such as PET having electrical insulation, and the corresponding primary The coil 3 or the secondary coil 4 is formed in a circular arc length that covers a range of 1/2 or more in the circumferential direction, and the end 3a or the secondary coil 4 of the primary coil 3 from each opening 11a, 12a. The end portion 4 is extended outward and fitted.

  Furthermore, flat plate portions 11b and 12b extending in parallel outward are integrally formed at both ends facing the openings 11a and 12a of the first and second holders 11 and 12, respectively. Both end portions 3a and 4a of the first and second coils 3 and 4 are guided outward along the lines 11b and 12b.

  Moreover, the length dimension of the axial direction of each of the 1st and 2nd holders 11 and 12 is the winding part around which the attached primary coil 3 is wound, or the secondary coil 4 is wound. It is set to the length dimension of the winding part in the axial direction. Then, both ends of the first and second holders 11 and 12 in the axial direction, which are opposed to the side wall 9 of the ferrite core 6, protrude from the outer peripheral surface and come into contact with the partition plate 2. The parts 11c and 12c are integrally formed.

  On the other hand, as shown in FIG. 6, the arc portions of the first and second holders 11 and 12 are surrounded by the central portion of the side wall portion 9 facing the first and second holders 11 and 12. A cylindrical surface 13 is formed along the axial direction. Further, on both side portions of the cylindrical surface 13 in the direction orthogonal to the axial direction, flat surface portions 14 facing the flat plate portions 11b and 12b of the first and second holders 11 and 12 are formed.

  And the edge part on the opposite side to the opening parts 11a and 12a in the collar parts 11c and 12c of the 1st and 2nd holders 11 and 12 protrudes further outward from the collar parts 11c and 12c, and the side wall part 9 Anti-rotation portions 11d and 12d that are in contact with the flat surface portion 14 are formed. Also, the flat plate portions 11b and 12b of the first and second holders 11 and 12 are bent at the tips of the side wall portion 9 from the flat surface portion 14 side to the side surface 15 side, and are retained to engage with the side surface 15. Portions 11e and 12e are formed.

  Incidentally, each of the first and second holders configured as described above has an inner diameter that is equal to or slightly smaller than the outer diameter of the primary coil 3 or the outer diameter of the secondary coil 4 to be mounted. When the outer periphery of the primary coil 3 or the secondary coil 4 is mounted, the openings 11a and 12a are expanded, and the primary coil 3 or 2 is restored by elastic force after passing through the maximum outer diameter portion of the coil. It is formed in dimensions so as to be fitted to the outer periphery of the next coil 4.

In the transformer having the above configuration, the insulation covering the range of 1/2 or more in the circumferential direction of the primary and secondary coils 3 and 4 over the entire length of the primary and secondary coils 3 and 4 in the axial direction. Since the first and second holders 11 and 12 in the shape of ring-opening cylinders made of a conductive resin are mounted, the primary coil indicated by the thick arrow in FIG. 5 by these first and second holders 11 and 12 The creepage distance L ₁ between the primary coil 3 and the secondary coil 4 and the creepage distance L ₂ between the primary and secondary coils 3 and 4 and the side wall 9 of the philite core 6 are secured to a predetermined length. can do.

  In addition, after the primary coil 3 and the secondary coil 4 are formed by winding the first and second winding portions of the bobbin 1, the first and second holders 11 are disposed on the outer circumferences of the first and second holders 11, respectively. By fitting and mounting 12, it is possible to prevent the winding from rewinding. For this reason, even when the wire diameter of the winding is increased, the assembly accuracy can be improved easily and reliably, and the manufacturing cost can be reduced.

  At this time, the first and second holders 11 and 12 are formed in an open cylindrical shape, and the end portions 3a and 4a of the primary and secondary coils 3 and 4 are outwardly extended from the respective openings 11a and 12a. Thus, the first and second holders 11 and 12 do not interfere with the both-end drawn portions 3 a and 4 a of the primary and secondary coils 3 and 4.

  Furthermore, flat plate portions 11b and 12b extending in parallel outward are formed at both ends facing the openings 11a and 12a of the first and second holders 11 and 12, respectively, and the flat plate portions 11b and 12b respectively Since both ends 3a and 4a of the primary and secondary coils 3 and 4 are guided, the windings become thick, and even when the lead portions 3a and 4a are used as connection terminals as they are, the respective flat plate portions The positioning accuracy of both end portions 3a and 4a can be improved by 11b and 12b.

  In addition, since the first and second holders 11 and 12 are provided with anti-rotation portions 11d and 12d that protrude from the outer peripheral surface thereof and abut against the flat surface portion 14 of the side wall portion 9, the first and second holders 11 and 12 are formed. After the holders 11 and 12 are fitted to the outer peripheries of the primary and secondary coils 3 and 4 and the core 7 is disposed around the holders 11 and 12, the first and second anti-rotation portions 11 d and 12 d are in contact with the side wall portion 9. It is possible to prevent the second holders 11 and 12 from being displaced in the circumferential direction.

  In addition, retaining portions 11e and 12e that engage with the side surface 15 of the side wall portion 9 are formed at the tips of the flat plate portions 11b and 12b formed on the openings 11a and 12a side of the first and second holders 11 and 12, respectively. Therefore, after the core 7 is arranged, the first and second holders 11 and 12 can be prevented from falling off from the primary and secondary coils 3 and 4.

1 Bobbin 2 Partition plate 3 Primary coil (first coil)
4 Secondary coil (second coil)
6 Ferrite core 9 Side wall part 11 First holder 12 Second holder 11a, 12a Opening part 11b, 12b Flat plate part 11c, 12c Gutter part 11d, 12d Anti-rotation part 13 Cylindrical surface 14 Flat part

Claims (4)

A cylindrical bobbin in which a first winding part and a second winding part are formed in the axial direction by a partition plate protruding annularly from the outer peripheral surface, and the first and second winding parts of the bobbin In a transformer comprising a first coil and a second coil wound respectively on the core, and a core that surrounds the outer periphery of the bobbin to form a closed magnetic circuit,
The first coil extends at both ends in the same direction, and the second coil extends at both ends in the same direction,
The outer circumferences of the first and second coils have axial lengths of the first and second winding portions, respectively, and 1 / of the circumferential direction of the first and second coils. The ring-opening cylindrical first and second holders made of an insulating resin covering two or more ranges are fitted by extending both ends of the coil outwardly from the respective openings. Transformer.   The core has a pair of side wall portions extending in the axial direction with the first and second coils interposed therebetween, and each of the first and second holders has both axial end portions. The transformer according to claim 1, wherein a flange that protrudes from the outer peripheral surface and abuts against the partition plate is formed at least in a portion facing the side wall of the core.   At both ends that define the opening of the first and second holders, flat plates that extend outwardly in parallel and guide both ends of the first and second coils, respectively. The transformer according to claim 1, wherein the transformer is formed.   The side wall portion of the core is formed with a cylindrical surface surrounding the bobbin and the first and second holders at a central portion of the opposing surface, and flat plate portions of the first and second holders on both sides of the cylindrical surface. 2. A flat portion opposing to the flat portion is formed, and the first and second holders are formed with anti-rotation portions that protrude from respective outer peripheral surfaces and come into contact with the flat portion. The transformer according to any one of 1 to 3.

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