JP2008218754A - Transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transformer providing a reduced size by effectively using a space of a bobbin, meanwhile, capable of increasing the number of adjacent turns on an identical bobbin. <P>SOLUTION: The transformer 1 comprises a core 2, a primary winding 3 having a coil 7 with a wire 6 wound on an outer circumference of the core 2 more than once in a larger diameter direction, and a secondary winding 4 comprising one turn structured metal plate material. The primary winding 3 comprises one end 6a of the wire 6 arranged on an inner periphery side of the coil 7, and the other end 6a of the wire 6 arranged on an outer periphery of the coil 7. The secondary winding 4 comprises a through-hole 10 going through the core 5, a pair of terminal parts 11, and a guiding means 12 for guiding one end of the wire 6 arranged on an inner periphery side of the coil 7 from the inner periphery side to the outer periphery side of the coil 7 with the surface of the secondary winding 4 press contacted to the surface of the coil 7. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a transformer, and more particularly to a transformer that is applied to a large-capacity switching power supply apparatus and uses a wire as a primary winding and a plate-like member as a secondary winding.

  Conventionally, a transformer applied to a large-capacity switching power supply device uses a metal plate for a secondary winding because a large current flows on the secondary side (for example, Patent Document 1). Normally, electric wires are used for both the primary winding and the secondary winding in the transformer winding. However, in Patent Document 1, a secondary winding in which a large current flows by using a metal plate for the secondary winding. It is configured to lower the resistance value of the line.

  Generally, in this type of primary winding, as shown in FIG. 5, the electric wire 101 is wound in a flat shape in order in the diameter increasing direction to form the coil portion 102, so The other end 104 is disposed on the outer peripheral side of the coil portion 102. Therefore, the primary winding causes one end 103 of the electric wire 101 to be sent to the outside from the inner peripheral side to the outer peripheral side of the coil portion 102 across the coil portion 102, and the other end 104 of the electric wire 101 is connected to the coil portion 102. It is configured to electrically connect the one end 103 and the other end 104 to an external component by sending them to the outside as they are from the outer peripheral side.

The transformer is configured by installing the primary winding on the outer periphery of a cylindrical winding frame of a bobbin and winding the secondary winding through an insulating sheet from above.
JP-A 64-30463

  However, in the transformer configured with the primary winding as described above, since the one end 103 of the electric wire 101 straddles the coil portion 102 from the inner peripheral side to the outer peripheral side, the secondary wound around the surface of the primary winding. The winding is lifted by the diameter of the electric wire 101, and the entire transformer is thickened accordingly. That is, the portion 105 corresponding to the diameter of the electric wire 101 becomes a dead space, and there is a problem that the winding frame cannot be used effectively as the entire transformer.

  Therefore, in view of the above-described problems, the present invention provides a transformer that can effectively reduce the size of the reel by using the space of the reel, and can increase the number of turns if the reel is the same. Objective.

  In order to achieve the above object, the invention according to claim 1 includes a core, a primary winding including a coil portion in which an electric wire is wound around the outer periphery of the core in order in a large diameter direction, and a single turn structure. A transformer having a secondary winding made of a metal plate material, wherein the primary winding has one end of the electric wire disposed on the inner peripheral side of the coil portion, and the other end of the electric wire is positioned on the outer peripheral side of the coil portion. The secondary winding includes the through-hole through which the core is inserted, a pair of terminal portions, and the surface of the secondary winding in contact with the surface of the coil portion. And a guiding means for guiding one end of the electric wire disposed on the inner peripheral side of the coil portion from the inner peripheral side to the outer peripheral side of the coil portion.

  The invention according to claim 2 is characterized in that the guiding means is formed at the periphery of the through hole.

  The invention according to claim 3 is characterized in that the guiding means is a recess.

  The invention according to claim 4 is characterized in that the guiding means is a bottomed groove.

  The invention according to claim 5 is characterized in that a plurality of the primary windings and the secondary windings are alternately arranged.

  According to the transformer of the first aspect of the present invention, the induction means is provided, so that the surface of the secondary winding is disposed on the inner peripheral side of the coil portion while being in contact with the surface of the coil portion. Since one end of the electric wire can be guided from the inner peripheral side to the outer peripheral side of the coil portion, the space of the winding frame can be effectively used, and the size can be reduced. Can be increased.

  Moreover, according to the transformer of Claim 2, the end of the electric wire arrange | positioned at the inner peripheral side of the coil part used as the outer peripheral surface of a core can be reliably guide | induced to the outer peripheral side.

  According to the transformer of the third aspect, since the position of one end of the electric wire can be visually recognized from above, the secondary winding can be easily positioned and installed.

  According to the transformer of the fourth aspect, it is possible to suppress a reduction in the cross-sectional area of the secondary winding accompanying the installation of the induction means.

  Further, according to the transformer of the fifth aspect, the leakage can be reduced by the amount of increase in the number of layers.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. A transformer 1 shown in FIG. 1 includes a core 2, a primary winding 3, and a secondary winding 4. The transformer 1 generates and changes a magnetic flux passing through the core 2 by causing a current to flow intermittently through the primary winding 3 as a whole. The magnetic flux generated and changed in this way is linked to the secondary winding 4 so that a voltage can be induced on the secondary winding 4, that is, the secondary side of the transformer 1.

  The core 2 is made of a high permeability member such as an iron core or a ferrite core, and includes a cylindrical leg portion 5. The primary winding 3 includes a three-layer insulated electric wire 6 similar to the conventional one, and includes a coil portion 7 formed by winding the electric wire 6 a plurality of times in the radial direction. In the primary winding 3, one end 6 a of the electric wire 6 at the beginning of winding is arranged on the inner peripheral side of the coil portion 7, and the other end 6 b of the electric wire 6 at the end of winding is connected to the outer periphery of the coil portion 7. It is arranged on the side. Accordingly, one end 6a of the primary winding 3 is sent to the outside across the coil portion 7 from the inner peripheral side to the outer peripheral side of the coil portion 7. On the other hand, the other end 6 b of the primary winding 3 is sent to the outside as it is from the outer peripheral side of the coil portion 7. The coil portion 7 of the primary winding 3 is wound around the leg portion 5 of the core 2. The secondary winding 4 is formed from a flat plate-like metal plate material such as a copper plate. An insulating plate 8 is provided in the middle of the primary winding 3.

  The secondary winding 4 includes a through hole 10 through which the leg portion 5 of the core 2 is inserted, a pair of terminal portions 11 and a concave portion 12 as a guiding means, and sandwiches the primary winding 3 in a sandwich shape. Be placed. The recess 12 is formed by cutting the periphery of the through hole 10 into a “U” shape. The recess 12 extends in the radial direction from the periphery of the through hole 10 and is formed to be longer than the length in the direction perpendicular to the axis of the primary winding 3 whose depth is the winding width, and the width of the electric wire 6 constituting the primary winding 3. It is formed longer than the diameter.

  The transformer 1 configured as described above is configured such that the surface of the secondary winding 4 is brought into contact with the surface of the coil portion 7 and the primary winding 3 is sandwiched between the secondary windings 4. Yes. Here, as described above, the primary winding 3 is fed with the end 6a straddling the coil portion 7 from the inner peripheral side to the outer peripheral side of the coil portion 7, so that the axis of the entire primary winding 3 is transmitted. The direction length is a length obtained by adding the diameter of the electric wire 6 to the height of the coil portion 7. Accordingly, when the primary winding 3 is sandwiched between the normal secondary winding 4 made of a metal plate material, the surface of the secondary winding 4 is lifted from the surface of the coil portion 7 by the diameter of the electric wire 6. A dead space is generated between the surface of 4 and the coil portion 7. However, according to the secondary winding 4 having the recess 12 according to the present invention, the surface of the secondary winding 4 is formed by inserting one end 6a of the electric wire 6 into the recess 12 as shown in FIG. One end 6a of the electric wire 6 straddling the coil portion 7 can be guided from the inner peripheral side to the outer peripheral side of the coil portion 7 by the concave portion 12 while being in contact with the surface of the primary winding 3. Therefore, the transformer 1 can be shortened in the axial direction by the diameter of the electric wire 6, so that the size reduction can be realized by effectively utilizing the space of the winding frame.

  In the transformer 1, the surface of the secondary winding 4 can be brought into contact with the surface of the primary winding 3, so that the primary winding 3 and the secondary winding 4 are magnetically coupled. Can be improved. In addition, since the transformer 1 is actually configured by laminating a plurality of primary windings 3 and secondary windings 4 in the axial direction in layers, the leakage can be reduced by an increase in the number of layers. it can.

  On the other hand, when the same reel is used, that is, when the axial length is the same as the conventional length, the number of layers per unit length can be increased compared to the conventional one. When the number of layers per unit length is increased as compared with the conventional case, in the transformer 1 of the present invention, the cross-sectional area per unit length can be increased for both the primary winding 3 and the secondary winding 4. The rise can be suppressed.

  Further, since the guiding means is the recess 12, the position of the one end 6a of the electric wire 6 can be visually confirmed from above, so that the secondary winding 4 can be easily and reliably positioned with respect to the primary winding 3. Can be installed.

  In the embodiment described above, the case where the concave portion 12 is provided as the guiding means has been described. However, as shown in FIG. 3, a bottomed groove portion 20 may be provided instead of the concave portion 12. The groove portion 20 is formed so as to extend in the radial direction from the periphery of the through hole 10, has a length in the height direction that is at least longer than the diameter of the electric wire 6, and a length in the radial direction is a length perpendicular to the axis of the primary winding 3. The circumferential length is longer than the diameter of the electric wire 6 constituting the primary winding 3. Thus, by providing the bottomed groove portion 20 as the guiding means, it is possible to suppress a reduction in the cross-sectional area of the secondary winding 4 due to the installation of the guiding means. That is, by using the groove portion 20 as the guiding means, the cross-sectional area of the secondary winding 4 can be increased compared to the case where the concave portion 12 is provided.

  Further, as the guiding means, as shown in FIG. 4, one end 6 a of the electric wire 6 may be sent to the outer peripheral side from between the through hole 10 and the core 2. In this case, since the recess 12 provided on the periphery of the through hole 10 has a depth sufficient for the diameter of the electric wire 6, the reduction in the cross-sectional area of the secondary winding 4 can be further suppressed.

  The present invention is not limited to this embodiment, and various modifications can be made within the scope of the gist of the present invention.

1 is a perspective view showing an overall configuration of a transformer according to the present invention. It is a fragmentary sectional view same as the above. It is a fragmentary sectional view showing a modification same as the above. It is a fragmentary sectional view showing another modification same as the above. It is a figure which shows a prior art example same as the above, (A) Top view, (B) Front view.

Explanation of symbols

1 transformer 2 core 3 primary winding 4 secondary winding 6 electric wire 7 coil part
10 Through hole
11 Terminal
12 Recessed part (guidance means)
20 Groove (guidance means)

Claims (5)

The core,
A primary winding provided with a coil portion in which an electric wire is wound around the outer periphery of the core a plurality of times in the radial direction;
In a transformer having a secondary winding made of a metal plate material of a single turn structure,
The primary winding is
One end of the electric wire is arranged on the inner peripheral side of the coil part, and the other end of the electric wire is arranged on the outer peripheral side of the coil part,
The secondary winding is
A through hole for passing through the core;
A pair of terminal portions;
One end of the electric wire arranged on the inner peripheral side of the coil part is guided from the inner peripheral side to the outer peripheral side of the coil part while keeping the surface of the secondary winding in contact with the surface of the coil part. And a transformer.   The transformer according to claim 1, wherein the guide means is formed on a peripheral edge of the through hole.   The transformer according to claim 2, wherein the guiding means is a recess.   The transformer according to claim 2, wherein the guide means is a bottomed groove portion.   The transformer according to any one of claims 1 to 4, wherein a plurality of the primary windings and the secondary windings are alternately arranged.

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