JP2000012335A - Transformer for communications equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transformer which has enhanced effective permeability and an improved distortion factor without enlarging outer dimensions. SOLUTION: In thin magnetic metal plates 11 and 12 constituting a core 1, first magnetic path strips 111 and 121 are inserted alternately into holes 20 on both sides in the coil winding axis direction of a coil part 2 to stack the first magnetic path strips 111 and 121, and second magnetic path strips 112 and 122, 113 and 123 are stacked outside the coil part 2. An auxiliary magnetic metal plate 3 is provided outside the coil part 2 and disposed on the second magnetic path strips 122 and 123 and a continuous strip 120. The auxiliary magnetic metal plate 3 has bent strips 301 and 302 bent in the same direction on two opposed sides. The bent strips 301 and 302 are disposed on both sides in the coil winding axis direction of the coil part 2 and press both opposed end faces of the core 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a transformer,
More particularly, the present invention relates to a transformer suitable for a communication device.

[0002]

2. Description of the Related Art Transformers for communication equipment, such as modem transformers, are required to transmit signal waveforms without distortion in high-speed signal transmission. This is because the distortion of the signal waveform causes a bit error of data, which causes a communication failure at high speed. For this reason, as an important characteristic required for a modem transformer, a distortion factor characteristic for evaluating how much a signal waveform is distorted is emphasized.

It is known that the distortion can be improved by increasing the effective magnetic permeability of the core. One means for increasing the effective magnetic permeability is to increase the volume of the core. However, this means cannot meet the demands for downsizing and high-density mounting. In particular, in the case of a structure in which a plurality of permalloys are laminated while penetrating through the holes formed in the coil portion, the cross-sectional area of the core is determined by the hole diameter of the coil portion. In this case, the hole diameter must be increased, or the shape of the core must be expanded outward in the plane of the metal magnetic thin plate. However, when the hole diameter is increased, the coil portion inevitably increases in size. Further, when the shape of the core is expanded outward when viewed from the plane of the metal magnetic thin plate, the plane shape becomes large. In any case, it is impossible to meet the demands for downsizing and high-density mounting.

Another means for increasing the effective magnetic permeability is
The core is made of a magnetic material having high magnetic permeability. As a specific means, in a transformer for a modem, a metal magnetic material such as permalloy has been conventionally used for a core. Since the metal magnetic material has a low electric resistivity, an eddy current easily flows when used as it is for the core. For this reason,
An assembly structure is adopted in which a U-shaped or E-shaped metal magnetic thin plate is alternately inserted into the hole of the coil portion from both sides in the coil winding axis direction and laminated.

However, in this laminated assembly structure, voids are formed on both sides in the winding axis direction due to the U-shaped or E-shaped shape of the metal magnetic thin plate, and the voids increase the magnetic resistance and reduce the effective magnetic permeability. It has the problem of lowering.

When the core is formed by laminating metal magnetic thin plates, it is necessary to prevent the metal magnetic thin plates from coming out of the holes of the coil portion. When the metal magnetic thin plates are connected to each other with, for example, an adhesive as a means for preventing the detachment, a stress is generated in the metal magnetic thin plates due to thermal expansion and contraction of the adhesive, and the characteristics of the core are degraded.

Japanese Unexamined Patent Publication No. Hei 6-053057 discloses a small transformer in which an effective magnetic permeability is improved by providing another iron core on the surface of a laminated E-type iron core outside the coil bobbin. However, in this transformer, it is not possible to fill the gap generated due to the shape of the E-shaped core on both sides in the coil winding axis direction. For this reason, it cannot be avoided that the magnetic resistance increases due to the air gap and the effective magnetic permeability decreases.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a transformer having an improved effective magnetic permeability and an improved waveform distortion without increasing the external dimensions.

Another object of the present invention is to provide a transformer capable of avoiding a decrease in effective magnetic permeability due to a gap formed on both sides of a core in a coil winding axis direction.

It is still another object of the present invention to provide a transformer capable of preventing a metal magnetic thin plate constituting a core from coming out of a hole of a coil portion without deteriorating the characteristics of the core.

[0011]

In order to solve the above-mentioned problems, a transformer according to the present invention comprises a coil unit, a core,
At least one auxiliary metal magnetic plate. The coil portion has a hole penetrating in the coil winding axis direction. The core is formed by laminating a plurality of metal magnetic thin plates.

Each of the metal magnetic thin plates includes a first magnetic path piece, a second magnetic path piece, and a continuous piece. The first magnetic path piece and the second magnetic path piece are arranged at an interval, one end is continuous via the continuous piece, and the other end is open.

Each of the metal magnetic thin plates is provided with the first
Magnetic path pieces are alternately inserted into the holes of the coil section from both sides in the coil winding axis direction of the coil section and stacked, and the second magnetic path piece is formed of the coil section. It is laminated outside.

[0014] The auxiliary metal magnetic plate is provided outside the coil portion, and is provided on the second magnetic path piece and the continuous piece.

[0015] Among the auxiliary metal magnetic plates, one auxiliary metal magnetic plate has, on two opposing sides, bent pieces bent in the same direction, and the bent pieces are arranged in the coil winding axis direction of the coil portion. , And presses opposing end faces of the core.

As described above, since the core is formed by laminating metal magnetic thin plates, a metal magnetic material having a high magnetic permeability, for example, a permalloy thin plate is used to improve the effective magnetic permeability and to reduce the waveform distortion. Can be improved. Even if a metal magnetic material having a low electric resistivity is used, the core is formed by laminating metal magnetic thin plates, so that eddy current is suppressed.

Each of the metal magnetic thin plates includes a first magnetic path piece, a second magnetic path piece, and a continuous piece. The first magnetic path piece and the second magnetic path piece are arranged at an interval, one end is continuous via a continuous piece, and the other end is open. The annular core can be formed by alternately inserting and laminating the magnetic path pieces from both sides in the coil winding axis direction of the coil portion into the hole of the coil portion.

The auxiliary metal magnetic plate is provided outside the coil portion, and is set on the second magnetic path piece and the continuous piece.
According to this structure, the cross-sectional area of the core is substantially increased.
Moreover, the auxiliary metal magnetic plate itself has a high magnetic permeability. Therefore, the effective magnetic permeability is increased, and the waveform distortion is improved.

Further, since the auxiliary metal magnetic plate is provided outside the coil portion and is disposed on the second magnetic path piece and the continuous piece, the planar shape of the core does not increase. Although the thickness in the stacking direction increases, the core is inserted into the hole of the coil portion, and the core surface is at a position lower than the surface of the coil portion. Further, the auxiliary metal magnetic plate is thin. Therefore, the auxiliary metal magnetic plate fits within the height of the coil portion. Therefore, there is no substantial increase in the shape when viewed in the height direction.

Further, as described above, in the core formed by laminating metal magnetic thin plates, air gaps are formed on both sides in the coil winding axis direction. According to the transformer according to the present invention, among the auxiliary metal magnetic plates, one auxiliary metal magnetic plate is
On opposite two sides, there are bent pieces bent in the same direction, and the bent pieces are arranged on both sides of the coil portion in the coil winding axis direction, and press opposing end faces of the core. For this reason, the voids of the core are covered with the bent pieces on the opposite end faces of the core. Therefore, the gap is magnetically bypassed by the bent piece, and the magnetic resistance in the gap is reduced, and the effective magnetic permeability is further increased.

Further, the bent pieces of the auxiliary metal magnetic plate are arranged on both sides of the coil portion in the coil winding axis direction, and the bent pieces press the opposite end faces of the core, so that the core is constituted. It is possible to prevent the metal magnetic thin plate from coming out of the hole of the coil portion. Moreover, unlike the case where the metal magnetic thin plates are joined to each other with, for example, an adhesive or the like, the laminated metal magnetic thin plates can be pressed without generating stress. Therefore, the characteristics of the core are not deteriorated.

Other objects, configurations and advantages of the present invention will be described in more detail with reference to the accompanying drawings. The accompanying drawings are merely examples.

[0023]

FIG. 1 is a partially exploded perspective view of a transformer according to the present invention. FIG. 2 is a cross-sectional view of the transformer shown in FIG. 1 along the coil winding axis direction. FIG.
FIG. 2 is a partially cutaway sectional view of the transformer shown in FIG. 1 as viewed from a coil winding axis direction. FIG. 4 is a sectional view taken along line 4-4 in FIG. As shown, the transformer according to the present invention includes a coil unit 2, a core 1, and at least one auxiliary metal magnetic plate 3.

The coil section 2 has a hole 20 penetrating in the coil winding axis direction. The transformer shown in the example is
Furthermore, the coil part 2 is formed in the coil winding frame 4 including the coil winding frame 4 and having the hole 20. At both ends of the coil winding frame 4, there are terminals 6 for connecting the coil terminals of the coil unit 2.

The core 1 includes a plurality of metal magnetic thin plates 11, 1,
2 are laminated. In FIG. 1, the metal magnetic thin plates 11 and 12 are extracted and shown. Metal magnetic thin plate 1
The thicknesses of 1 and 12 are 0.15 mm or less, particularly preferably 0.1 mm or less.

Since the core 1 is formed by laminating the metal magnetic thin plates 11 and 12, a metal magnetic material having a high magnetic permeability, for example, a permalloy thin plate is used to improve the effective magnetic permeability and reduce the waveform distortion. Can be improved. Even if a metal magnetic material having a low electric resistivity is used, the core 1 is formed by laminating the metal magnetic thin plates 11 and 12, so that the eddy current is suppressed.

The metal magnetic plate 11 includes a first magnetic path piece 111.
And the second magnetic path pieces 112 and 113 and the continuous piece 110. The first magnetic path piece 111 and the second magnetic path piece 112
It is arranged at intervals, one end is continuous via the continuous piece 110, and the other end is open. The first magnetic path piece 111 and the second magnetic path piece 113 are arranged at an interval, one end is continuous via the continuous piece 110, and the other end is open.

The metal magnetic plate 12 also has a first magnetic path piece 121.
And second magnetic path pieces 122 and 123 and a continuous piece 120. The first magnetic path piece 121 and the second magnetic path piece 122
It is arranged at intervals, one end is continuous via the continuous piece 120, and the other end is open. The first magnetic path piece 121 and the second magnetic path piece 123 are arranged at an interval, one end is continuous via the continuous piece 120, and the other end is open.

In the metal magnetic thin plates 11 and 12, the first magnetic path pieces 111 and 121 are alternately inserted into the holes 20 of the coil section 2 from both sides in the coil winding axis direction of the coil section 2 and laminated. , The second magnetic path pieces (112 and 122), (113)
And 123) are laminated outside the coil unit 2.

As described above, the first magnetic path pieces 111 and 121 of the metal magnetic thin plates 11 and 12 are alternately inserted into the holes 20 of the coil section 2 from both sides of the coil section 2 in the coil winding axis direction. And by laminating, the annular core 1 can be constituted.

Specifically, the first magnetic path piece 111 of the metal magnetic thin plate 11 is inserted into the cylindrical hole 20 of the coil section 2 along the direction of arrow A. The first magnetic path piece 121 of the metal magnetic thin plate 12 is inserted into the cylindrical hole 20 of the coil section 2 along the direction of arrow B. The core 1 is formed by laminating a required number of metal magnetic thin plates 11 inserted along the direction of arrow A and metal magnetic thin plates 12 inserted along the direction of arrow B.

The auxiliary metal magnetic plate 3 is provided outside the coil portion 2 and includes the second magnetic path pieces 122 and 123 and the continuous piece 12.
It is set on 0. Unlike the illustration, the auxiliary metal magnetic plate 3 includes the second magnetic path pieces 112 and 113 and the continuous piece 11.
0 may be installed. The thickness of the auxiliary metal magnetic plate 3 is 0.15 mm or less, particularly preferably 0.1 mm.
mm or less. The auxiliary metal magnetic plate 3 can be made of the same material as the metal magnetic plates 11 and 12 constituting the core 1, for example, permalloy. The auxiliary metal magnetic plate 3 shown in the embodiment is
It is one. Alternatively, the auxiliary metal magnetic plate 3 may be composed of a plurality of divided pieces.

The auxiliary metal magnetic plate 3 has bent pieces 301 and 302 bent in the same direction on two opposite sides. The bent pieces 301 and 302 are arranged on both sides of the coil portion 2 in the coil winding axis direction, and press opposite opposing end surfaces of the core 1.

As described above, the auxiliary metal magnetic plate 3 is provided outside the coil section 2 and has the second magnetic path piece (112, 1).
13), (122, 123) and continuous pieces 110, 120
It is installed on. According to this structure, the cross-sectional area of the core 1 is substantially increased. Moreover, the auxiliary metal magnetic plate 3
Has a high magnetic permeability itself. Therefore, the effective magnetic permeability is increased, and the waveform distortion is improved.

Further, since the auxiliary metal magnetic plate 3 is provided outside the coil portion 2 and is installed on the second magnetic path pieces 122 and 123 and the continuous piece 120, the plane shape of the core is large. It does not change. Although the thickness in the stacking direction increases, the core 1 is inserted into the hole 20 of the coil portion 2,
The core surface is at a position lower than the surface of the coil unit 2.
Further, the auxiliary metal magnetic plate 3 is thin. Therefore, the auxiliary metal magnetic plate 3 fits within the height H of the coil portion 2. Therefore, there is no substantial increase in the shape when viewed in the height direction.

Incidentally, as described above, the metal magnetic thin plate 1
When the core 1 is formed by laminating the metal magnetic sheets 1 and 12, one of the metal magnetic thin sheets 11 and 12 adjacent to each other is used.
In 1, the open other end is located on one side in the coil axis direction, and the continuous piece 110 is located on the other side in the coil axis direction. The other metal magnetic thin plate 12 has another open end positioned on the other side in the coil winding axis direction, and a continuous piece 120.
Are located on one side in the coil winding axis direction. For this reason, in the laminated metal magnetic thin plates 11 and 12, the gap g (see FIG. 3) is alternately provided on one side or the other side in the coil winding axis direction.
Has occurred.

According to the transformer according to the present invention, among the auxiliary metal magnetic plates 3, one auxiliary metal magnetic plate 3 has bent pieces 301 and 302 bent in the same direction on two opposing sides. Bent pieces 301 and 302 are arranged on both sides of the coil portion 2 in the coil winding axis direction, and press opposing end surfaces of the core 1. For this reason, the gap g of the core 1 is
Are covered with bent pieces 301 and 302 at opposite end faces. Therefore, the gap g is formed by the bent pieces 301 and 302.
Magnetically bypasses, the magnetic resistance in the gap decreases, and the effective magnetic permeability further increases.

Further, the bent piece 30 of the auxiliary metal magnetic plate 3
1 and 302 are arranged on both sides of the coil portion 2 in the direction of the coil winding axis, and the bent pieces 301 and 302 press opposing end surfaces of the core 1, so that the metal magnetic thin plate 11 constituting the core 1 is formed. , 12 can be prevented from coming out of the hole 20 of the coil portion 2. Further, unlike the case where the metal magnetic thin plates 11 and 12 are connected to each other by, for example, an adhesive or the like, the stacked metal magnetic thin plates 11 and 12 do not generate stress.
Can be held down. Therefore, the characteristics of the core 1 are not deteriorated.

The metal magnetic thin plate 11 shown in the embodiment
Two second magnetic path pieces 112 and 113 are provided. The second magnetic path pieces 112 and 113 are arranged on both sides of the first magnetic path piece 111. The shape of such a metal magnetic thin plate 11 is E-shaped. Similarly, the metal magnetic thin plate 12
Two second magnetic path pieces 122 and 123 are provided. The second magnetic path pieces 122 and 123 are arranged on both sides of the first magnetic path piece 121. The shape of such a metal magnetic thin plate 12 is E-shaped. In the embodiment, the E-shaped metal magnetic thin plate 1 is used.
The core 1 is formed by alternately laminating the cores 1 and 12.

The auxiliary metal magnetic plate 3 is preferably made of a thin metal plate that can be easily bent. In this case, the bent pieces 301 and 302 are easily formed.

The auxiliary metal magnetic plate 3 shown in the embodiment is formed in an annular shape having a hole 30 through which the coil portion passes through the plate surface. The annular auxiliary metal magnetic plate 3 is passed through the coil portion 2 into the hole 30 so that the second magnetic path pieces 122 and 123 and the continuous piece 1
20. The auxiliary metal magnetic plate 3 is fixed to the surface of the core 1 using an adhesive or the like.

FIG. 5 is a comparative example of a BH curve by a transformer for a modem. Curve B1 shows the characteristics when the auxiliary metal magnetic plate 3 is not used, and curve B2 shows the improved characteristics when the auxiliary metal magnetic plate 3 is placed. The characteristic B2 has a larger effective magnetic permeability in the entire range from a small magnetic field to a large magnetic field than the characteristic B1. Therefore, the characteristic B2 has better linearity than the characteristic B1, and the waveform distortion is improved.

Next, the waveform distortion rate of the embodiment shown in FIGS. 1 to 4 was measured. For comparison with this example, comparative examples 1 and 2 were prepared, and the waveform distortion rate was measured for these as well.

Comparative Example 1 is a conventional transformer for a modem, and has a thickness of 0.2 mm as a metal magnetic thin plate constituting a core.
mm permalloy sheet is used. Comparative Example 2 is an improved transformer for a modem, and a permalloy thin plate having a thickness of 0.1 mm is used as a metal magnetic thin plate. The embodiment is the transformer shown in FIGS. 1 to 4, in which a 0.15 mm-thick permalloy thin plate is used as the metal magnetic thin plate, and the auxiliary metal magnetic plate 3 is mounted.

FIG. 6 is a characteristic diagram showing the relationship between the effective magnetic permeability and the waveform distortion. The point S1 on the characteristic curve is the waveform distortion rate given by the effective magnetic permeability of the transformer of Comparative Example 1, the point S1
Reference numeral 2 denotes a waveform distortion rate given by the effective magnetic permeability of the transformer of Comparative Example 2. A point S3 on the characteristic curve indicates a waveform distortion rate given by the effective magnetic permeability of the transformer of the example.

In Comparative Example 2, as compared with Comparative Example 1, the width of the gap as viewed from the laminating direction of the metal sheets constituting the core is smaller, and the influence of the gap is reduced. Therefore, as shown in FIG. 6, Comparative Example 2 has higher effective magnetic permeability and lower waveform distortion rate than Comparative Example 1. As compared with these Comparative Examples 1 and 2, in the examples, the effective magnetic permeability was increased and the waveform distortion was significantly reduced due to the auxiliary metal magnetic plate 3.

FIG. 7 is a partially exploded perspective view showing another embodiment of the transformer according to the present invention. In the embodiment shown in FIG. 7, a plurality of auxiliary metal magnetic plates 31 and 32 are provided and are stacked on each other. Therefore, a plurality of auxiliary metal magnetic plates 3
The effect of increasing the effective magnetic permeability by the first and the second 32 is obtained. Further, of the auxiliary metal magnetic plates 31 and 32, the auxiliary metal magnetic plate 32 provided at the uppermost portion is provided with bent pieces 321, 3
22. Accordingly, the bent pieces 321 and 322 of the auxiliary metal magnetic plate 32 can prevent the pieces from coming off and improve the effective magnetic permeability. A plurality of flat auxiliary metal magnetic plates similar to the auxiliary metal magnetic plate 31 may be provided.

FIG. 8 is a partially exploded perspective view showing still another embodiment of the transformer according to the present invention. In the figure, FIG.
The same components as those described above are denoted by the same reference numerals. In the embodiment shown in FIG. 8, a plurality of auxiliary metal magnetic plates 3
1 and 32 are provided and stacked on each other. Therefore, similarly to the embodiment shown in FIG. 7, the effect of increasing the effective magnetic permeability by the plurality of auxiliary metal magnetic plates 31, 32 can be obtained. Of the auxiliary metal magnetic plates 31 and 32, the auxiliary metal magnetic plate 32 installed on the uppermost portion has bent pieces 32 on four sides.
1 to 324. Accordingly, the bent pieces 321 to 324 of the auxiliary metal magnetic plate 32 prevent the four sides from coming off and improve the effective magnetic permeability.

[0049]

As described above, according to the present invention, the following effects can be obtained. (A) It is possible to provide a transformer in which the effective magnetic permeability is improved and the waveform distortion is improved without increasing the external dimensions. (B) It is possible to provide a transformer capable of avoiding a decrease in effective magnetic permeability due to a gap formed on both sides of the core in the coil winding axis direction. (C) It is possible to provide a transformer capable of preventing the metal magnetic thin plate constituting the core from falling out of the hole of the coil portion without deteriorating the characteristics of the core.

[Brief description of the drawings]

FIG. 1 is a partially exploded perspective view of a transformer according to the present invention.

FIG. 2 is a cross-sectional view of the transformer shown in FIG. 1 along a coil winding axis direction.

FIG. 3 is a partially cutaway cross-sectional view of the transformer shown in FIG. 1 as viewed from a coil winding axis direction.

FIG. 4 is a sectional view taken along line 4-4 in FIG. 3;

FIG. 5 is a BH characteristic diagram.

FIG. 6 is a diagram showing the relationship between effective magnetic permeability and waveform distortion.

FIG. 7 is a partially exploded perspective view showing another embodiment of the transformer according to the present invention.

FIG. 8 is a partially exploded perspective view showing still another embodiment of the transformer according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Core 11, 12 Metal magnetic thin plate 2 Coil part 3 Auxiliary metal magnetic plate 301, 302 Bending piece

Claims (6)

[Claims] 1. A transformer including a coil part, a core, and at least one auxiliary metal magnetic plate, wherein the coil part has a hole penetrating in a coil winding axis direction. A plurality of metal magnetic thin plates are laminated, each of the metal magnetic thin plates includes a first magnetic path piece,
The first magnetic path piece and the second magnetic path piece are arranged at intervals, one end is continuous via the continuous piece, and the other end is Each of the metal magnetic thin plates is open, and the first magnetic path piece is
From both sides in the coil winding axis direction of the coil portion, alternately,
Inserted into the hole of the coil portion, and laminated,
The second magnetic path piece is laminated outside the coil part, and the auxiliary metal magnetic plate is provided outside the coil part, and is provided on the second magnetic path piece and the continuous piece. Is installed, of the auxiliary metal magnetic plate, one auxiliary metal magnetic plate,
It has bent pieces that bend in the same direction on two opposite sides,
A transformer in which the bent pieces are arranged on both sides of the coil portion in the direction of the coil winding axis and press opposing end faces of the core. 2. The transformer for a communication device according to claim 1, wherein each of said metal magnetic thin plates has two said second magnetic path pieces.
A transformer, wherein the second magnetic path piece is disposed on both sides of the first magnetic path piece. 3. The transformer according to claim 1, wherein the auxiliary metal magnetic plate has a hole in the plate surface through which the coil portion passes. 4. The transformer according to claim 1, wherein a plurality of the auxiliary metal magnetic plates are provided and stacked on each other. 5. The transformer according to claim 4, wherein, among the auxiliary metal magnetic plates, an auxiliary metal magnetic plate installed at an uppermost portion has the bent piece. 6. The transformer according to claim 1, wherein one of the auxiliary metal magnetic plates is an auxiliary metal magnetic plate.
Transformer with bent pieces on the four sides that bend in the same direction.