JP2019096725A - High frequency transformer and high frequency coil - Google Patents

Abstract

To provide a high frequency transformer and a high frequency coil with reduced generation of an eddy current in a winding.SOLUTION: A copper plate 110 and a copper plate 120 are disposed between a core piece 130A and a core piece 130B of a core 130. The copper plate 110 is a C-shaped copper plate and has terminals 111 and 112 at both ends. Similarly, the copper plate 120 is a C-shaped copper plate and has terminals 121 and 122 at both ends. A current flows in the copper plate 110 in a direction from the terminal 111 toward the terminal 112 or in the opposite direction. Similarly, a current flows in the copper plate 120 in a direction from the terminal 121 toward the terminal 122 or in the opposite direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a high frequency transformer and a high frequency coil.

  Conventionally, a core, a primary winding consisting of a winding body wound around the core, and a secondary winding consisting of a metal plate material having a one-turn structure are provided, and the core is inserted through the metal plate material. A transformer is provided with a through hole for holding and holding a pair of terminal parts separated by the through hole, and the winding body and the metal plate material are alternately arranged with respect to the core. (See, for example, Patent Document 1).

Japanese Patent Application Publication No. 2006-013094

  By the way, in the conventional transformer, the flux fringing in the gap portion of the core may cause an eddy current in the primary winding and / or the secondary winding. In particular, when a leakage flux is interlinked with a winding formed of a metal plate in the thickness direction, generation of eddy current becomes remarkable.

  When an eddy current is generated, the primary winding and / or the secondary winding is heated, so measures against heat dissipation are required.

  Therefore, it is an object of the present invention to provide a high frequency transformer and a high frequency coil in which the generation of an eddy current in a winding is suppressed.

A high frequency transformer according to an embodiment of the present invention includes a primary winding, a secondary winding disposed to overlap the primary winding, a first yoke, a first leg, and the first yoke. A first core piece having a second leg projecting from the
A second yoke, a third leg, and a fourth leg projecting from the second yoke and in contact with the second leg, the primary side winding between the first core piece and the first core piece; And a second core piece sandwiching the secondary winding, wherein the first leg and the third leg are closer than the inner peripheries of the primary winding and the secondary winding in plan view. The first side is disposed on the first side and the second side in the inner area, and protrudes toward the second yoke and the first yoke, respectively, and faces the third leg of the first leg. A first gap between the surface and the second surface of the third leg facing the first leg, a second gap between the first leg and the second yoke, and the third leg And a third gap between the first and second yokes.

  It is possible to provide a high frequency transformer and a high frequency coil in which the generation of an eddy current in the winding is suppressed.

It is a figure showing high frequency transformer 100 of an embodiment. It is a figure which shows the state which decomposed | disassembled the core 130. FIG. It is a figure which shows the AA arrow cross section of FIG. It is a figure which shows the BB arrow cross section of FIG. It is a figure showing high frequency transformer 10 for comparison. It is a figure showing high frequency transformer 100M1 by the 1st modification of an embodiment. It is a figure which shows the high frequency transformer 100M2 by the 2nd modification of embodiment.

  Hereinafter, an embodiment to which the high frequency transformer of the present invention and the high frequency coil are applied will be described.

Embodiment
FIG. 1 is a diagram showing a high frequency transformer 100 according to an embodiment. The high frequency transformer 100 includes a copper plate 110, a copper plate 120, and a core 130, and can transmit AC power at a frequency of about 10 kHz to about several MHz from the primary side to the secondary side, as an example.

  Below, in addition to FIG. 1, it demonstrates using FIG. 2 thru | or FIG. FIG. 2 is a view showing the core 130 in a disassembled state. FIG. 3 is a cross-sectional view taken along the line AA of FIG. FIG. 4 is a cross-sectional view taken along the line B-B in FIG. Further, in the following, description will be made using an XYZ coordinate system, and planar view means XY planar view.

  The copper plate 110 and the copper plate 120 are disposed between the core piece 130A and the core piece 130B of the core 130. The copper plate 110 and the copper plate 120 have the same shape, as one example. The copper plate 110 is a C-shaped copper plate and has terminals 111 and 112 at both ends. Similarly, the copper plate 120 is a C-shaped copper plate and has terminals 121 and 122 at both ends. A current flows in the copper plate 110 in the direction from the terminal 111 toward the terminal 112 or in the opposite direction. Similarly, current flows in the copper plate 120 in the direction from the terminal 121 toward the terminal 122 or in the opposite direction.

  Here, as an example, seven copper plates are shown as the copper plate 110 and the copper plate 120, and by connecting the upper five (Z-axis positive direction side) five copper plates 110 in series, five primary windings are provided. The lower (Z-axis negative direction side) two copper plates 120 are connected in series to be used as a secondary winding of two turns.

  In order to connect the five copper plates 110 in series, for example, the terminals 112 and 111 may be connected by wiring from the terminal 112 of the uppermost copper plate 110 to the terminal 111 of the lowermost copper plate 110 in order. . Similarly, in order to connect two copper plates 120 in series, the terminal 122 of the upper copper plate 120 and the terminal 121 of the lower copper plate 120 may be connected by wiring.

  Alternatively, five copper plates 110 may be connected in parallel to form a single-turn primary winding, or two copper plates 120 may be connected in parallel to form a single-turn secondary winding. Also, the number of copper plates 110 and copper plates 120 may be any number and may be equal to each other.

  In addition, between the copper plates 110, between the copper plate 110 and the copper plate 120, and between the copper plates 120 are insulated by arranging insulating paper or the like, and between the copper plate 110 and the copper plate 120 and the core 130 as well. Is provided but omitted here.

  The core 130 is divided into two, and includes a core piece 130A and a core piece 130B. The core pieces 130A and the core pieces 130B have the same shape. For this reason, first, the core piece 130A will be described.

  The core piece 130A has a yoke 131A, a main leg 132A, and side legs 133A and 134A. The core piece 130A is an example of a first core piece. The yoke 131A is an example of a first yoke, the main leg 132A is an example of a first leg, and the side legs 133A and 134A are an example of a second leg.

  The yoke 131A is a plate-like portion extending along the XY plane, and a main leg 132A projecting in the negative Z-axis direction is provided on the negative side in the negative Y-axis at the central portion in the X-axis direction. . The yoke 131A is also provided with side legs 133A and 134A which project in the negative Z-axis direction from the ends in the negative X-axis direction and the positive X-axis direction.

  The main leg portion 132A is a semi-elliptical columnar body in a plan view, and is provided so as to protrude in the negative Z-axis direction from the negative side in the negative Y-axis direction at the central portion of the yoke 131A in the X-axis direction. The main legs 132A are arranged alternately with the main legs 132B in a staggered manner in the Y-axis direction. That is, main leg 132A is provided on the first side in the region inside the inner circumferences of copper plates 110 and 120 in plan view, and main leg 132B is provided on the second side opposite to the first side. Be

  The main leg 132A has an opposing surface 132A1 that faces (faces) the opposing surface 132B1 of the main leg 132B of the core piece 130B. The opposing surface 132A1 is a plane parallel to the XZ plane and faces the opposing surface 132B1 while facing the Y-axis positive direction side. The facing surface 132A1 is an example of the first surface. The main leg 132A has a curved surface 132A2 curved in an arc shape in the negative Y-axis direction. The curved surface 132A2 is offset from the Y-axis negative direction end of the yoke 131A to the Y-axis positive direction side.

  The main leg 132A is disposed in an elliptical shape with the main leg 132B of the core piece 130B in a state in which the core pieces 130A and 130B are assembled. When the core pieces 130A and 130B are assembled, the gap (the gap in the Y-axis direction) between the opposing surface 132A1 of the main leg 132A and the opposing surface 132B1 of the main leg 132B is d1. The gap d1 is an example of a first gap.

  Further, the height of the main leg 132A in the Z-axis direction ensures a gap d2 between the end face on the Z-axis negative direction side and the yoke 131B of the core piece 130B in a state where the core pieces 130A and 130B are assembled. Set to the desired thickness. The gap d2 is an example of a second gap, and d2> d1.

  The main leg 132A establishes a magnetic path having an air gap with the main leg 132B in a state where the core pieces 130A and 130B are assembled.

  The side legs 133A and 134A have a rectangular parallelepiped shape, and are provided so as to protrude in the Z-axis negative direction from the end portions on the X-axis negative direction side and the X-axis positive direction side of the yoke 131A. The side legs 133A and 134A respectively abut the side legs 133B and 134B of the core piece 130B, and form a magnetic path between the side legs 133B and 134B. The length in the X-axis direction, the length in the Y-axis direction, and the height in the Z-axis direction of the side leg portion 133A and the side leg portion 134A are equal to each other.

  The distance between the side leg portion 133A and the main leg portion 132A and the distance between the side leg portion 134A and the main leg portion 132A are set to be slightly larger than the widths of the copper plates 110 and 120. The lengths of the side legs 133A and 134A in the Y-axis direction are equal to the length of the yoke 131A in the Y-axis direction, and the lengths of the side legs 133A and 134A in the X-axis direction are the core pieces 130A and 130B assembled. In the state, the length is set such that sufficiently low reluctance can be obtained.

  The core piece 130B has a yoke 131B, a main leg 132B, and side legs 133B and 134B, and has the same configuration as the core piece 130A. For this reason, the core piece 130B will be briefly described. The core piece 130B is an example of a second core piece. The yoke 131B is an example of a second yoke, the main leg 132B is an example of a third leg, and the side legs 133B and 134B are an example of a fourth leg.

  The yoke 131B is a plate-like portion extending along the XY plane, similarly to the yoke 131A. The yoke 131B is provided with a main leg 132B and side legs 133B and 134B.

  The main leg portion 132B is a semi-elliptical columnar body in a plan view, and is provided so as to project in the positive Z-axis direction from the positive Y-axis direction at the center of the yoke 131B in the X-axis direction. As described above, the main legs 132B are arranged alternately with the main legs 132A offset in position in the Y-axis direction.

  The main leg portion 132B has an opposing surface 132B1 that faces (faces) the opposing surface 132A1 of the main leg portion 132A of the core piece 130A. The gap between the facing surface 132B1 and the facing surface 132A1 is d1. The facing surface 132B1 is an example of the second surface.

  Further, the main leg portion 132B has a curved surface 132B2 curved in an arc shape in the negative Y-axis direction. The curved surface 132B2 is at a position offset to the Y-axis negative direction side with respect to the end portion on the Y-axis positive direction side of the yoke 131B.

  Further, the height of the main leg 132B in the Z-axis direction ensures a gap d3 between the end face on the Z-axis positive direction side and the yoke 131A of the core piece 130A in a state where the core pieces 130A and 130B are assembled. Set to the desired thickness. The gap d3 is an example of the third gap, d3> d1, and d3 = d2. That is, the height of the main leg 132B is equal to the height of the main leg 132A.

  Further, the main leg portion 132B constructs a magnetic path having an air gap between itself and the main leg portion 132A in a state where the core pieces 130A and 130B are assembled.

  The side legs 133B and 134B have a rectangular parallelepiped shape, and are provided so as to protrude in the Z-axis positive direction from the end portions on the X-axis negative direction side and the X-axis positive direction side of the yoke 131B. The side legs 133B and 134B respectively abut the side legs 133A and 134A of the core piece 130A, and form a magnetic path between the side legs 133A and 134A. The sizes of the side legs 133B and 134B in the X-axis direction and the Y-axis direction are equal to those of the side legs 133A and 134A, respectively.

  As described above, the core 130 has the main legs 132A and 132B that form the magnetic path with the air gap therebetween. The gap d1 between the opposing surface 132A1 of the main leg 132A and the opposing surface 132B1 of the main leg 132B is greater than the gap d2 between the main leg 132A and the yoke 131B and the gap d3 between the main leg 132B and the yoke 131A. small. Therefore, the magnetic path between the main legs 132A and 132B is mainly the magnetic path between the facing surface 132A1 having the smallest gap and the lowest magnetic resistance, and the facing surface 132B1.

  Such a configuration can be realized by alternately arranging the main legs 132A and the main legs 132B in the Y-axis direction. The opposing surface 132A1 and the opposing surface 132B1 function as a primary winding and a secondary winding, respectively, in the YZ plane view in which a cross section in which the main leg 132A and the main leg 132B are adjacent is obtained. And 90.degree. Different from the direction (XY plane direction) extending in a planar manner.

  Further, on both sides of the opposing surface 132A1 of the main leg 132A from which the gap d1 is obtained and the opposing surface 132B1 of the main leg 132B, sections separated by gaps d2 and d3 larger than the gap d1 are provided.

  For this reason, the fringing of the magnetic flux generated between the opposed surface 132A1 of the main leg 132A and the opposed surface 132B1 of the main leg 132B passes through the section separated by the gap d2 and the section separated by the gap d3. It is possible to suppress the copper plate 110 and the copper plate 120 from being extended.

  Therefore, according to the embodiment, it is possible to provide the high frequency transformer 100 capable of suppressing the generation of the eddy current in the copper plate 110 (primary winding) and the copper plate 120 (secondary winding).

  Here, for example, a comparison with the high frequency transformer 10 for comparison as shown in FIG. 5 will be described. FIG. 5 is a view showing a high frequency transformer 10 for comparison. FIG. 5 shows a cross-sectional structure corresponding to FIG. The high frequency transformer 10 for comparison has a configuration in which the core 130 of the high frequency transformer 100 of the embodiment is replaced with the core 13. The copper plate 110 and the copper plate 120 are the same as those of the high frequency transformer 100 of the embodiment.

  The core 13 has core pieces 13A and 13B. Core pieces 13A and 13B have a configuration in which main legs 132A and 132B of core pieces 130A and 130B of the embodiment are replaced with main legs 13A1 and 13B1, respectively.

  The main legs 13A1 and 13B1 have an elliptical columnar shape in plan view, and the lengths in the X-axis direction and the Y-axis direction are all equal to the height in the Z-axis direction. The main legs 13A1 and 13B1 are equal in position in the X-axis direction and in the Y-axis direction, and are opposed in the Z-axis direction.

  The lengths of the main legs 13A1 and 13B1 in the X-axis direction are equal to those of the main legs 132A and 132B, and the length in the Y-axis direction is from the end of the main leg 132A in the positive Y-axis direction. It is the length to the end on the Y-axis negative direction side of 132B. In addition, the height in the Z-axis direction of the main legs 13A1 and 13B1 is lower than that of the main legs 132A and 132B, and is separated by a predetermined gap.

  When such two main legs 13A1 and 13B1 are used, the fringing magnetic flux at the end portion on the Y-axis positive direction side and the end portion on the Y-axis negative direction side interlink with the copper plate 110 and the copper plate 120. It will be done. The angle at which the fringing magnetic flux interlinks with the copper plate 110 and the copper plate 120 is perpendicular to the surface of the copper plate 110 in the copper plate 110 located at the central portion in the Z-axis direction among the seven copper plates 110 and 120. Further, among the seven copper plates 110 and 120, the copper plate 110 on the Z-axis positive direction side and the copper plate 120 on the Z-axis negative direction side are interlinked at an angle close to perpendicular to the plane. .

  For this reason, in the high frequency transformer 10 for comparison, an eddy current is generated on the XY plane of the copper plate 110 and the copper plate 120, and the copper plate 110 and the copper plate 120 are heated.

  On the other hand, in the high frequency transformer 100 according to the embodiment, the main legs 132A and the main legs 132B are alternately arranged with the positions shifted in the Y-axis direction, and the main legs facing each other with the minimum gap d1. Sections separated by gaps d2 and d3 larger than the gap d1 are provided on both sides of the opposite surface 132A1 of 132A and the opposite surface 132B1 of the main leg 132B.

  For this reason, it can suppress that the fringing magnetic flux between the opposing surface 132A1 of the main leg part 132A and the opposing surface 132B1 of the main leg part 132B leaks out of the core 130, and the copper plate 110 (primary winding And the generation of eddy currents in the copper plate 120 (secondary winding) can be suppressed.

  In the above description, the core 130 of the high-frequency transformer 100 has the side legs 133A and 133B and the side legs 134A and 134B on both sides of the main legs 132A and 132B. Only one of 133B and side legs 134A and 134B may be included. For example, when the high frequency transformer 100 does not include the side legs 134A and 134B, the yokes 131A and 131B may be only a section between the side legs 133A and 133B and the main legs 132A and 132B. Also, the main legs 132A and 132B may be handled as legs instead of the main legs.

  In the above, the embodiments using the copper plates 110 and 120 as the primary side winding and the secondary side winding have been described, but, for example, a plurality of conductive layers included in the wiring substrate are patterned in a C shape to form vias. It may be used as a primary side winding and a secondary side winding by connecting with each other.

  Further, in this case, for example, using a wiring board larger in plan view than the high frequency transformer 100, a part in plan view of a plurality of conductive layers of the wiring board is patterned in a C shape, and the main leg 132A And 132B, the side legs 133A and 133B, and the side legs 134A and 134B are formed in the wiring board, and the core pieces 130A and 130B are attached from both sides of the wiring board, respectively. And the high frequency transformer 100 may be integrated.

  In the above, the main legs 132A and the main legs 132B are alternately arranged in the Y-axis direction, but the main legs 132A and the main legs 132B are viewed in a plan view. The position may be shifted in the X-axis direction, or may be staggered in any direction in plan view.

  In the above description, the opposing surfaces 132A1 and 132B1 of the main legs 132A and 132B are perpendicular to the yokes 131A and 131B (standing at 90 degrees), but the rising angle is approximately 90 degrees. I hope there is. Moreover, as shown in FIG. 6, it may be diagonal, and as shown in FIG. 7, it may be step-like.

  FIG. 6 is a diagram showing a high frequency transformer 100M1 according to a first modification of the embodiment. The cross section shown in FIG. 6 corresponds to FIG. Here, differences from the high frequency transformer 100 shown in FIGS. 1 to 4 will be described.

  High frequency transformer 100M1 includes a copper plate 110, a copper plate 120, and a core 130M1. The core 130M1 has a core piece 130MA1 and a core piece 130MB1. The core piece 130MA1 has a main leg 132MA1 instead of the main leg 132A in FIGS. 1 to 4. Similarly, the core piece 130MB has a main leg 132MB1 instead of the main leg 132B of FIGS. 1 to 4.

  The main legs 132MA1 and 132MB1 have facing surfaces 132MA11 and 132MB11, respectively. The opposing surfaces 132MA11 and 132MB11 are oblique to the yokes 131A and 131B. Oblique means that the angle formed with the yokes 131A and 131B is greater than 0 degrees and less than 90 degrees. The facing surfaces 132MA11 and 132MB11 face each other across the gap d1 and are parallel to each other.

  Even in such a high frequency transformer 100M1, similarly to the high frequency transformer 100 shown in FIGS. 1 to 4, generation of eddy currents in the copper plate 110 (primary winding) and the copper plate 120 (secondary winding) is suppressed. it can.

  FIG. 7 is a diagram showing a high frequency transformer 100M2 according to a second modification of the embodiment. The cross section shown in FIG. 7 corresponds to FIG. Here, differences from the high frequency transformer 100 shown in FIGS. 1 to 4 will be described.

  High frequency transformer 100M2 includes a copper plate 110, a copper plate 120, and a core 130M2. The core 130M2 has a core piece 130MA2 and a core piece 130MB2. The core piece 130MA2 has a main leg 132MA2 instead of the main leg 132A of FIGS. 1 to 4. Similarly, the core piece 130MB has a main leg 132MB2 instead of the main leg 132B of FIGS. 1 to 4.

  The main legs 132MA2 and 132MB2 have facing surfaces 132MA21 and 132MB21, respectively. The opposing surfaces 132MA21 and 132MB21 are stepped. The opposing surfaces 132MA21 and 132MB21 are configured in a step shape with the gap d1 therebetween.

  Also in such a high frequency transformer 100M2, similarly to the high frequency transformer 100 shown in FIGS. 1 to 4, the generation of eddy currents in the copper plate 110 (primary winding) and the copper plate 120 (secondary winding) is suppressed. it can.

  Moreover, although the high frequency transformer 100, 100M1, and 100M2 were demonstrated above, the copper plate 110 and the copper plate 120 can be used as a coil (reactor) by connecting all the copper plate 110 and the copper plate 120 in series. In this case, the high frequency transformers 100, 100M1 and 100M2 can be regarded as high frequency coils.

  Although the high frequency transformer and the high frequency coil of the exemplary embodiment of the present invention have been described above, the present invention is not limited to the specifically disclosed embodiment, and from the scope of the claims Various modifications and variations are possible without departing.

100, 100M1, 100M2 high frequency transformer 110, 120 copper plate 130, 130M1, 130M2 core 130A, 130B, 130MA1, 130MB1, 130MA2, 130MB2 core pieces 131A, 131B yoke 132A, 132B, 132MA1, 132MB1, 132MA2, 132MB2 main legs 132A1, 132B1, 132MA11, 132MB11, 132MA21, 132MB21 Opposite surfaces 132A2, 132B2 Curved surfaces 133A, 134A, 133B, 134B Side legs

Claims (6)

Primary side winding,
A secondary winding disposed overlapping with the primary winding;
A first core piece having a first yoke, a first leg, and a second leg projecting from the first yoke;
A second yoke, a third leg, and a fourth leg projecting from the second yoke and in contact with the second leg, the primary side winding between the first core piece and the first core piece; And a second core piece sandwiching the secondary winding.
The first leg and the third leg are respectively disposed on the first side and the second side in an area inside the inner circumferences of the primary winding and the secondary winding in a plan view. It projects toward the second yoke and the first yoke,
A first gap between the first surface of the first leg facing the third leg and the second surface of the third leg facing the first leg is the first leg and the first gap. A second gap with a second yoke, and a high frequency transformer smaller than a third gap between the third leg and the second yoke.   2. The high frequency transformer according to claim 1, wherein the first surface and the second surface are surfaces which stand up to the first yoke and the second yoke, respectively.   The high frequency transformer according to claim 2, wherein an angle at which the first surface and the second surface rise with respect to the first yoke and the second yoke is 90 degrees, respectively.   The high frequency transformer according to claim 2, wherein the first surface and the second surface are surfaces which rise in a step-like manner with respect to the first yoke and the second yoke, respectively.   The high frequency transformer according to any one of claims 1 to 4, wherein the primary side winding and the secondary side winding are flat plate-like windings. A coil wound a plurality of times in a wound state;
A first core piece having a first yoke, a first leg, and a second leg projecting from the first yoke;
A second yoke, a third leg, and a fourth leg projecting from the second yoke and in contact with the second leg, and holding the coil between the first core piece and the fourth core; Including 2 core pieces and
The first leg and the third leg are respectively disposed on the first side and the second side in a region on the inner side than the inner periphery of the coil in a plan view, and are disposed on the second yoke and the first yoke. Each protruding towards the
A first gap between the first surface of the first leg facing the third leg and the second surface of the third leg facing the first leg is the first leg and the first gap. A second gap with a second yoke, and a high frequency coil smaller than a third gap between the third leg and the second yoke.

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