JP2677930B2 - Magnetic parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic component most suitable for high frequency applications, especially for transformers and choke coils of switching power supply devices.

[0002]

2. Description of the Related Art FIG. 17 is a circuit diagram showing a circuit example of a switching regulator.

A line filter 2 is connected to an AC power supply (commercial power supply of AC 100 V) 1 for preventing intrusion of noise from the outside and emission of noise from the inside to the line side. A rectifying / smoothing circuit 3 having a circuit for performing both-wave rectification of an AC power supply and smoothing a rectified output is connected. The rectifying / smoothing circuit 3 is connected to a switching circuit 4 for intermittently switching the DC output of the rectifying / smoothing circuit 3 and supplying the DC output to a transformer 5. The transformer 5 has two windings wound on the primary side and an output winding wound on the secondary side. A rectifier circuit 6 composed of a diode is connected to the output winding of the transformer 5, and an LC type smoothing circuit 7 is connected to this circuit. A load 8 (here, a resistor is used) is connected to the smoothing circuit 7. It is connected. A control circuit 9 is connected to the output side of the smoothing circuit 7, and the output thereof controls the switching circuit 4.

The line filter 2 includes a capacitor 21, a noise filter 22, and capacitors 23 and 24.
Both normal mode noise and common mode noise can be attenuated. The smoothing circuit 7 includes a capacitor 71, a choke coil 72, and a capacitor 73. Electrolytic capacitors are used for the capacitors 71 and 73, and for example, a drum-shaped core is used for the choke coil 72, and a winding is applied to this core portion.

In the circuit as described above, the DC output obtained by the rectifying / smoothing circuit 3 is applied to the switching circuit 4, and the switching circuit 4 is driven according to the output of the control circuit 9, whereby a high frequency pulse is generated. An electric current is passed through the transformer 5, and an AC voltage is generated in the output winding of the transformer 5. This AC voltage is supplied to the load 8 after being rectified by the rectifier circuit 6 and further removed of the ripple component by the smoothing circuit 7.

Since the output voltage of the smoothing circuit 7 fluctuates depending on the load state, the control circuit 9 controls the switching circuit 4 so as to correct the fluctuation. When the output voltage increases, the on-time of the switching circuit 4 is reduced, and conversely, when the output voltage decreases, the on-time is increased. By such control, a stable output voltage can always be obtained even if the load state changes.

By the way, in the switching power supply device, the magnetic parts such as the noise filter 22 and the choke coil 72 can be downsized by increasing the frequency. For example, as the frequency increases from 300 KHz to 500 KHz or higher, high-frequency loss due to eddy current, skin effect, etc. becomes a problem in the conventional single wire winding. For this reason,
In order to achieve higher efficiency and smaller size, it is necessary to further reduce high frequency copper loss. As a wire material to achieve this, attention has been paid to multi-parallel wires instead of conventional litz wires and copper foil.

The multiple parallel lines are, as shown in FIG.
A high-frequency electric wire in which each of a plurality of conductors (for example, enamel wire) 10 having a diameter of 0.05 to 1.0 mm is covered with an insulating film 11, and these are connected in parallel on the same plane in a flexible state. , Occupying about 30% more space than Litz wire
There are features that can be improved. And the reason why this wire material has better high frequency characteristics than copper foil is that it consists of minute wires,
This is because it is difficult for eddy currents to flow, the conductor circumference can be increased, and the surface area is larger than that of copper foil. This has the advantage that a large amount of current can be caused by the skin effect. Further, since the eddy current is small, the AC resistance at a high frequency is very small as compared with the copper foil, and the value has a good value of about 1/8 even at a frequency of 100 KHz.

Regarding the multiple parallel lines, for example, the 1991 Autumn Meeting of the Institute of Electronics, Information and Communication Engineers, "AC Resistance of Multiple Parallel Lines in Switching Power Supply" 3-2
52 pages and Furukawa Electric Co., Ltd. "Furukawa Electric Time Report"
No. 87 (December 1990), page 133.

[0010]

However, in the above-mentioned prior art, since a plurality of thin wires are subjected to insulation treatment with an insulating material such as a resin and then these are adhered in a planar shape,
Since it is flat and foil-shaped and thin, it is not easy to wind it onto a bobbin, etc. Furthermore, it is difficult to perform terminal treatment and drawing after winding, so there are many problems to be solved for practical use.

For example, as shown in FIG. 19, when winding an inner iron type (or EI type) core with multiple parallel wires, windings N ₂ , N ₃ , N ₄ are made on a resin bobbin 10. , N ₁ , N ₅
The bobbins 10 are arranged in a core 11 by interposing inter-layer paper 12 between them and wound in multiple layers. In this example, since the circuit has a small current capacity, the number of the multiple parallel lines is reduced and the coil is wound. Therefore, insulating paper is required for each layer,
It was difficult to wind because the space factor was very poor and there was a step between the windings.

An object of the present invention is to solve the above-mentioned problems in the prior art, and to provide a magnetic component that improves the space factor and facilitates winding, and facilitates terminal treatment and extraction after winding. Is to provide.

[0013]

In order to achieve the above object, the first means of the present invention is to provide a magnetic component using a plurality of parallel wires for windings , in which each of the plurality of parallel wires of the lead-out portion is provided.
Draw arcs of concentric circles on the same plane one by one
Bend in and pull out upwards
The ends of parallel lines are processed into litz wire.

In order to achieve the above object, the first aspect of the present invention
Method 2 is for magnetic parts that use multiple parallel wires for winding.
Part of the parallel part of the lead-out part in a flat plate shape.
Connected to the flat plate part of the worked cylindrical conductor,
The conductor is used as a lead wire.

[0015]

According to the above-mentioned first means, the lead-out portions of the multiple parallel lines are formed in concentric circles so as not to overlap in the length direction .
By curving so as to draw an arc and forming the litz wire at the tip end thereof, it is possible to prevent the lead portion from having a thickness.

According to the above-mentioned second means, the drawer portion
Connect the multiple parallel lines of to the flat plate part of the cylindrical conductor,
By using this columnar conductor as a lead wire, the thickness of the lead portion can be reduced.

[0017]

1 is a sectional view showing a reference example for explaining an embodiment of the present invention, and FIG. 2 is a front view showing a combination of one layer of the reference example of FIG.

In the conventional configuration shown in FIG. 19, one winding always takes one layer regardless of each winding width (it varies depending on the current capacity), whereas in the reference example, The smaller number of windings N ₁ and N ₄ is replaced by another winding N having a larger current capacity
₂ and N ₃ are combined, and a part of the winding is used for winding. That is, as shown in FIG. 2, the main winding N3 and the separate winding N1 are wound adjacent to each other on the same plane so that no gap is formed at the ends in the width direction. With such a configuration, the number of winding layers can be reduced and the space factor can be dramatically improved. As a result, the size of the transformer can be reduced.

In the above reference example, depending on the circuit used, when the voltage difference between the main winding and the separate winding is large, the withstand voltage between the windings may not be sufficient. To solve this problem, as shown in FIG. 3, a resin wire 15 without a conductor is inserted between the main winding 13 and the separate winding 14 and an insulator is interposed so as to ensure a withstand voltage. do it.

However, the use of multiple parallel lines as in the above reference example has a drawback in that there is no degree of freedom in the bending direction after drawing out the winding wire. That is, as shown in FIG. 4, which is a perspective view showing a state after the multi-parallel lines are drawn out, the conventional treatment of the multi-parallel line lead-out end is performed 90 ° upward from the coil-shaped winding body. It is bent and pulled out.
In such a drawing method, the wire can be bent only in the surface direction (thickness direction), and even if a transformer is formed by this winding, wiring cannot be performed when the transformer is mounted on the substrate. Further, since the leakage inductance at the winding start and winding end portions is small, when attempting to draw it out from the same portion, the thickness may be increased due to the overlapping of the bent portions, and the winding may not be possible. Furthermore, it is, of course, impossible to attach a pin to the bobbin and entangle the lead wire to pull out the pin, unlike the conventional transformer.

Therefore, in the first embodiment of the present invention,
As shown in FIG. 5, each of the parallel lines of
Curved one after another in the same plane to draw concentric circular arcs
The Litz wire is processed by pulling it up and twisting the tip. The configuration of this without developing overlaps the bent portion, there is no possibility to increase the winding thickness. In addition, the bending direction after drawing the winding wire is also free, and the bobbin can be bent on the pin.

In addition, the drawing portion has a round line in FIG.
As shown in, a cylindrical conductor having a flat plate portion 35 formed at one end
The body 36 is prepared, and the main winding 13 is provided on the cylindrical conductor 36.
Alternatively, the ends of the separate winding 14 may be connected. This
In the case of, as shown in (b) and (c) of FIG.
How to extend main winding 13 or separate winding 14 with respect to body 36
Connect so that the directions are orthogonal. By doing so, the effect of reducing the thickness of the drawn-out portion can be obtained.

FIG. 7 is a front view showing another example of the winding portion,
Here, the coupling degree of the transformer can be increased. As is well known, the degree of coupling of a transformer is particularly important in a switching power supply, and if the degree of coupling is poor, the surge voltage becomes large and the switching element is destroyed. This means that when an attempt is made to increase the frequency, the number of turns is reduced, and as a result, the degree of coupling is reduced, and the above problem becomes more prominent.

FIG. 8 is a sectional view showing a conventional general winding structure for increasing the degree of coupling between windings. Here, 1
The secondary winding is divided into two, 18a and 18b, the primary winding 18a is wound below the bobbin 10, and the secondary winding 19 is wound above this.
Is wound, the primary winding 18b is further wound on the secondary winding 19, and the secondary winding 19 is wound in a sandwich shape. In this winding method, since the secondary winding 19 is sandwiched between the primary windings 18, two primary windings 18 are required. For this reason, not only the winding thickness becomes large, but also it is necessary to connect the winding lead-out portions in parallel after drawing them out, which complicates the terminal treatment and requires man-hours, resulting in an increase in cost.

Therefore, in the example shown in FIG. 7, when it is necessary to previously insulate the parallel wires from the primary to the secondary, the primary windings 18 and 2 are wound.
An insulating tape 20 is inserted between the next windings 19, and the insulating tape 20 is sandwiched between the windings to overlap the windings. FIG. 9 shows a transformer constituted by such windings. In this configuration,
Since the secondary windings are alternately wound, it is possible to obtain a transformer having a small winding thickness and a high degree of coupling. In addition,
Although not shown, it is needless to say that the lead-out ends of the primary winding 18 and the secondary winding 19 are litz wire-shaped as shown in FIG.

FIG. 10 is a perspective view showing another example for further increasing the degree of coupling, and FIG. 11 shows the structure of multiple parallel lines used in this example. The multi-parallel lines 27 shown here have the same structure as the conventional example described above in which the conductors 25 are arranged in parallel at regular intervals and the conductors are covered with the resin material 26. Is made flat and the other surface is processed into a concave shape. This parallel line 2
FIG. 10 shows an example in which No. 7 is applied to a transformer.

FIG. 12 is a perspective view showing the structure of the winding portion of the transformer shown in FIG. Here, two parallel parallel lines 27a and 27b of the same shape are made into a primary winding and a secondary winding, and when these are superposed, as shown in FIG. The conductors 25 are opposed to each other and all of the conductors 25 are located on the same plane (a state in which the conductors of the multiple parallel lines 27a and the conductors of the multiple parallel lines 27b are alternately arranged). When the transformer is constructed by using the windings having such a configuration, it becomes as shown in FIG. 10, and the degree of coupling can be maximized. Further, since the flat surface is on the outside, the interlayer paper for eliminating the unevenness of the winding is unnecessary, and the transformer can be downsized while the coupling degree is increased. In the above example, the winding is primary -2
The case of the next winding has been described, but the present invention is not limited to this.

13, FIG. 14, FIG. 15 and FIG. 16 are perspective views showing the shape of a bobbin around which multiple parallel lines are wound, the drawing end of which is a litz wire (not shown).

The bobbin shown in FIGS. 13 to 16 is designed to enhance the workability of the winding. Usually, when the winding is composed of multiple parallel wires, it is wound around a cylindrical winding frame or bobbin. In this case, since the winding is flat, the winding start portion slips and moves, which makes it difficult to perform winding. Also,
Even if it can be wound, the degree of adhesion to the bobbin is weak, and it moves during the subsequent winding process, making it difficult to wind.

Therefore, in FIG. 13, stoppers 29 are provided at upper and lower two positions of the bobbin 28, and a winding wire 30 composed of multiple parallel wires is wound in a gap between the stoppers 29, and the winding wire 30 is pulled out. It is performed from the vicinity of the stopper 29. Alternatively, as shown in FIG. 14, the bobbin 2
It is also possible to provide a notch 31 in a part of the upper end of 8 and draw out the leader line from this part. As shown in FIG. 15, non-slip mesh projections 32 (or mesh grooves) are provided on the entire outer peripheral surface of the bobbin 28 to prevent the wound winding from slipping. Further, as shown in FIG. 16, a part of the bobbin 28 (preferably a winding start part) is provided with an adhesive material application surface 33 in the vertical direction, and the wound winding is fixed on the adhesive material application surface 33.

According to the structure shown in FIGS. 13 to 16, the winding can be prevented from slipping, the adhesion to the bobbin can be improved, and the winding can be reliably performed.

[0032]

As described above, according to the first aspect of the present invention, each of the parallel lines of the lead portion is provided one by one.
Bend it to draw circular arcs of concentric circles in the same plane.
Since the tips of the multiple parallel lines that have been pulled out are processed upward to form a litz wire, it is possible to prevent a thickness portion from occurring in the drawn portion.

According to the invention described in claim 2, the drawer portion
Connect the multiple parallel wires of the to the flat part of the cylindrical conductor, and
Since the columnar conductor of is used as the lead wire,
However, the thickness of the drawer portion can be further reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a reference example for explaining an embodiment of the present invention.

FIG. 2 is a front view showing a combination of one layer of the reference example of FIG.

FIG. 3 is a front view showing another reference example for explaining the embodiment of the present invention.

FIG. 4 is a perspective view showing a form of a conventional leader line when a plurality of parallel wires are wound in a coil shape.

FIG. 5 is a perspective view showing an embodiment of the present invention.

FIG. 6 is a perspective view showing another example of processing of the drawer end in the embodiment of FIG.

FIG. 7 is a front view showing another example of the winding portion.

FIG. 8 is a cross-sectional view showing an example of a conventional transformer having a general winding structure for increasing the degree of coupling between windings.

9 is a cross-sectional view showing a transformer constituted by the winding wire shown in FIG.

FIG. 10 is a cross-sectional view showing a case where a transformer is configured by another example of multiple parallel lines.

11 is a perspective view showing multiple parallel lines used in the transformer of FIG.

12 is a perspective view showing a winding structure in which the multiple parallel wires of FIG. 11 are combined.

FIG. 13 is a perspective view showing the shape of a bobbin around which multiple parallel lines are wound.

FIG. 14 is a perspective view showing another shape of the bobbin.

FIG. 15 is a perspective view showing still another shape of the bobbin.

FIG. 16 is a perspective view showing still another shape of the bobbin.

FIG. 17 is a circuit diagram showing a circuit example of a switching regulator.

FIG. 18 is a perspective view showing an example of a known structure of multiple parallel lines.

FIG. 19 is a sectional view showing an example of a conventional transformer in which multiple parallel wires are used for windings.

[Explanation of symbols]

10 bobbin 11 core 13 main winding 15 resin wire 18, 18a, 18b, 27a primary winding 19, 27b secondary winding 25 conductor 26 resin material 27 multiple parallel lines 28 bobbin 29 stopper 30 winding 31 notch 32 Mesh protrusion 33 Adhesive coating surface 35 Flat plate portion 36 Columnar conductor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nao Nakabachi, Shinmei-do, Nakameisei, Shibata-gun, Miyagi Prefecture 3-3, Tomei Ricoh Co., Ltd. (72) Inventor Shigeo Yamaguchi 2-6, Marunouchi, Chiyoda-ku, Tokyo No. 1 Furukawa Electric Co., Ltd. (72) Inventor Tsuneo Ikegami 1-14-6, Ichibancho, Aoba-ku, Sendai-shi, Miyagi (56) Reference JP-A-5-343241 (JP, A) JP-A-57- 197811 (JP, A) Actually open 2-81019 (JP, U) Actually open 57-87514 (JP, U)

Claims (2)

(57) [Claims] 1. In a magnetic component using multiple parallel lines for windings , each of the multiple parallel lines of the lead- out portion is the same.
Curve it so that it draws circular arcs of concentric circles in one plane.
A magnetic component, characterized in that it is drawn out in one direction, and the leading end portions of the drawn-out multiple parallel lines are processed into a litz wire shape. 2. A magnetic component using multiple parallel wires for windings.
And make a part of the parallel lines of the drawer part flat
Connect to the flat plate-shaped part of the processed cylindrical conductor,
A magnetic component characterized in that a columnar conductor is used as a lead wire .