JP2014049681A - Transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transformer including a plurality of high voltage coils which allows for reduction of extra time required for soldering at joints, or the like, while ensuring the insulation distance easily and achieving compaction.SOLUTION: In a transformer where a plurality of high voltage coils 10 and low voltage coils 11 are laminated alternately in the axial direction, a seamless wire 15 is wound continuously across a plurality of high voltage coils 10.

Description

  The present invention relates to a transformer used as a power transformer or the like in which a large current flows through a low voltage coil.

As a power transformer or a DC-DC converter used for an electric vehicle, a large server, or the like, a transformer in which a large current of 100 A or more flows in a secondary side low voltage coil is used.
In such a transformer, normally, the above-described increase in current is handled by using a metal flat plate having a low resistance value as the low voltage coil.

  By the way, when the low voltage coil is formed of a metal flat plate, the secondary low voltage coil and the primary high voltage coil cannot be formed into a layer winding structure. However, depending on the structure, there is a problem that coupling is poor and it is difficult to obtain desired characteristics.

  Therefore, conventionally, as shown in FIGS. 7 and 8, a high voltage coil 2 having a bobbin 2a provided with a winding 2b is disposed between two ring-shaped low voltage coils 1 made of a metal flat plate. A transformer was used. Reference numeral 3 in the figure is a pair of E-type ferrite cores that surround the low-voltage coil 1 and the high-voltage coil 2 to form a closed letter-shaped magnetic path, and reference numeral 4 indicates the ferrite core 3 and the low-voltage coil. 1 is an insulating plate interposed between the two.

According to the conventional transformer having the above-described configuration, it is possible to obtain excellent characteristics by sandwiching the high voltage coil 2 between the two low voltage coils 1 to enhance the coupling.
A power transformer having the above configuration is also disclosed in, for example, Patent Document 1 below.

JP 2001-267153 A

  In the transformer having such a configuration, when the characteristics are improved by further improving the coupling, the high voltage coil 2 is also divided as shown in FIGS. It is conceivable to adopt a configuration in which a plurality of low voltage coils 1 and high voltage coils 2 are alternately stacked in the axial direction by sandwiching the low voltage coil 1 by the above.

  However, in the transformer, after the wire 2b is wound around the bobbin 2a and the individual high voltage coils 2 are assembled, the terminals 2c of the wire 2b of the high voltage coil 2 are connected by soldering or the like. In addition, since it is necessary to construct the insulating cover 5 at the connection portion, there is a problem that a great deal of labor is required for these operations.

  In addition, when it is necessary to secure a predetermined insulation distance from the low-voltage coil 1, a flange 2d that protrudes outward is further formed on the bobbin 2a, and a terminal is formed outside the flange 2d. It is necessary to cope by connecting 2c, and as a result, the length L of the terminal 2c is increased, leading to an increase in size as a whole.

  The present invention has been made in view of the above circumstances, and can reduce an extra effort such as a soldering process at a connection portion, easily secure an insulation distance, and realize downsizing. It is an object of the present invention to provide a transformer including a plurality of high voltage coils.

  In order to solve the above problems, the invention according to claim 1 is a transformer in which a plurality of high voltage coils and low voltage coils are alternately stacked in the axial direction of each other. No wire is continuously wound across the plurality of high voltage coils.

  According to a second aspect of the present invention, in the first aspect of the present invention, the plurality of high voltage coils are each wound by α winding.

  Furthermore, the invention described in claim 3 is characterized in that the wire constituting the high voltage coil is a three-layer insulated wire.

  According to the invention described in any one of claims 1 to 3, since a plurality of high-voltage coils are continuously wound with a seamless wire across the plurality of high-voltage coils, Thus, it is not necessary to connect the lead wires between the high-voltage coils, so that extra work such as soldering at the connecting portion can be reduced.

  In addition, even in the case of a specification that requires a predetermined insulation distance between the low voltage coils, there is no connection part of the wire material between the plurality of high voltage coils, so there is no need to consider the insulation distance. As a result, the overall transformer can be reduced in size. Therefore, even when a three-layer insulated wire is used as a measure against the insulation distance in the high voltage coil as in the invention described in claim 3, it can be dealt with as it is without causing an excessive increase in size of the transformer.

  Further, as in the invention described in claim 2, if each of the plurality of high voltage coils is configured by α winding, the lead wire from the inner periphery of the bobbin is eliminated, and the bobbin is wound with a predetermined number of turns. Since it can be densely wound, it is possible to achieve further downsizing.

It is a perspective view showing one embodiment of a transformer concerning the present invention. It is AA sectional view taken on the line of FIG. FIG. 3 is a cross-sectional view taken along line BB in FIG. 1. It is a perspective view which shows the coil part for high voltage | pressure of FIG. FIG. 2 is an exploded perspective view of FIG. 1. FIG. 4 is an exploded view of FIG. 3. It is a longitudinal cross-sectional view of the conventional transformer. It is a longitudinal cross-sectional view in the direction orthogonal to FIG. It is a longitudinal cross-sectional view of another conventional transformer. It is a longitudinal cross-sectional view in the direction orthogonal to FIG.

  1 to 6 show an embodiment of a transformer according to the present invention. This transformer includes two high-voltage coils 10 on the primary side and three low-voltage coils 11 on the secondary side. The high voltage coil 10 and the low voltage coil 11 surround the ferrite core 12 which forms a closed magnetic circuit.

  Here, the high-voltage coil 10 has a substantially cylindrical shape in which a three-layer insulated wire (wire) 15 is wound around an insulating bobbin 14. On the other hand, the low voltage coil 11 is a ring-opening ring-shaped flat plate member formed by punching a copper plate, and terminals 11a extending outward are integrally formed at both ends thereof. The high-voltage coil 10 and the low-voltage coil 11 are alternately stacked in the axial direction so that their axis lines coincide with each other.

  As a result, the low voltage coil 11 is disposed at both ends and the center in the axial direction, and the high voltage coil 10 is disposed between the low voltage coils 11. A pair of E-type ferrite cores 12 are arranged opposite to the outer peripheries of the high-voltage coil 10 and the low-voltage coil 11 so as to surround the outer peripheries and to be inserted into the central opening so as to form a closed letter-shaped magnetic path as a whole. Is arranged. Reference numeral 13 denotes an insulating plate interposed between the ferrite core 12 and the low voltage coil 11.

  In this transformer, a single three-layer insulated wire 15 having no seam is wound around two high-voltage coils 10 continuously across the two high-voltage coils 10. The three-layer insulated wire 15 is wound around the bobbin 14 of each high-voltage coil 10 by α winding and in the same direction.

  Further, on the outer periphery of the bobbin 14 of the high-voltage coil 10, the three-layer insulated wire 15 is positioned on a portion 15 a where the three-layer insulated wire 15 is bridged from one high-voltage coil 10 to the other high-voltage coil 10. The small protrusion 14a is formed. By the way, if a groove or projection for guiding and positioning the three-layer insulated wire 15 is formed on the small protrusion 14a, the three-layer insulated wire 15 can be more stably connected from one high-voltage coil 10 to the other. It is suitable that it can be bridged over the high voltage coil 10.

  When assembling the transformer having the above structure, first, the three-layer insulated wire 15 is wound around the bobbin 14 of one high-voltage coil 10 and then the three-layer insulated wire 15 extending from the one high-voltage coil 10 is attached. By winding α around the bobbin 14 of the other high-voltage coil 10, two high-voltage coils 10 in which one three-layer insulated wire 15 is continuously wound are created as shown in FIG. 4.

  Next, as shown in FIG. 6, the three low voltage coils 11 are arranged so as to sandwich the two high voltage coils 10 therebetween, and the insulating plate 13 is arranged on the outer surface of the outer low voltage coil 11, The transformer assembly is completed by surrounding the high-voltage coil 10 and the low-voltage coil 11 with the pair of E-type ferrite cores 12.

  In the transformer having the above configuration, a single three-layer insulated wire 15 having no seam is wound around two high voltage coils 10 continuously across the two high voltage coils 10. Further, it is not necessary to connect the lead wires between the high voltage coils, so that extra work such as soldering at the connecting portion can be reduced.

  Further, when a predetermined insulation distance is required between the low-voltage coil 11 and the three-layer insulated wire 15 as a wire for the high-voltage coil 10, a single three-layer insulated wire 15 is connected to 2 Since the two high-voltage coils 10 are continuously wound around, there is no need to consider the insulation distance from the low-voltage coil 11, and as a result, the size of the entire transformer can be reduced.

  In addition, since the three-layer insulated wire 15 is wound around each of the bobbins 14 of the two high-voltage coils 10 by α winding, the lead wire of the three-layer insulated wire 15 from the inner periphery of the bobbin 14 is eliminated, and A winding having a predetermined number of turns can be tightly wound around the bobbin 14. Thereby, further miniaturization can also be achieved.

  In the above embodiment, the transformer according to the present invention has been described only in the case where two high voltage coils 10 and three low voltage coils 11 are alternately stacked in the axial direction. However, the present invention is not limited to this, and it may be configured by combining more high-voltage coils 10 and low-voltage coils 11.

Further, the wire rod for forming the high-voltage coil 10 is not limited to the three-layer insulated wire 15 described above, and various wire rods can be used based on the specifications of the transformer.
Further, for the low voltage coil 11, depending on the magnitude of the flowing current, it is possible to use a wire having a large wire diameter instead of the above-described ring-opening ring-shaped flat plate member.

10 High-voltage coil 11 Low-voltage coil 14 Bobbin 15 Three-layer insulated wire (wire material)

Claims (3)

In a transformer in which a plurality of high voltage coils and low voltage coils are alternately stacked in the axial direction of each other,
The transformer, wherein the plurality of high voltage coils are formed by continuously winding a seamless wire across the plurality of high voltage coils.   The transformer according to claim 1, wherein each of the plurality of high voltage coils is wound by α winding.   The transformer according to claim 1 or 2, wherein the wire constituting the high-voltage coil is a three-layer insulated wire.

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