JPH07302715A - Coil device - Google Patents

Abstract

PURPOSE:To provide a thin type coil device which has large inductance and can made to flow a large current. CONSTITUTION:A coil device 1 is provided with five board-shaped magnetic materials 2 which are arranged parallel with each other at specified intervals, and a conducting wire 3 wound wave-wise between the specified intervals of the magnetic materials 2. The magnetic material 2 is composed of ferrite as oxide magnetic material. When a DC current is made to flow in the coil device 1, upward and downward magnetization directions are alternately applied to each of the magnetic materials 2. Magnetic flux flows so as to draw a loop through air gaps between the respective magnetic materials 2. By the flow of magnetic flux, it becomes equivalent to the formation of a suitable gap in a magnetic circuit. Hence the coil device 1 has almost the same characteristics as the core shape of general use wherein a suitable gap is formed, and can be easily thinned.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil device having a large inductance and capable of flowing a large current.

[0002]

2. Description of the Related Art FIG. 8 shows a large number of transformers which have a large inductance and can carry a large current.
In the conventional coil device 10 shown in FIG. 3, an E-shaped core 11 is arranged in combination as shown in the figure, and a winding 13 is wound around the central leg 12.

However, the conventional coil device 10 has a problem that it is difficult to reduce the thickness because the core shape and the winding 13 wound around the central leg portion 12 project as shown in FIG.

In order to solve this problem, there is known one using a thinly flattened core 11 as shown in FIG. 10 (Japanese Utility Model Publication No. 57-186010). In this case, however, the strength of the legs is weak, making manufacture difficult, and in order to obtain the target inductance, the winding 13 must be provided so as to wrap around the legs in multiple layers. Because of the winding 13, the leg portion becomes thick, and as a result, it cannot be sufficiently thinned.

Further, as a thin coil device, as shown in FIG. 11, a micro magnetic core 15 (electrical coil) in which a spiral or zigzag sheet coil 16 is sandwiched by a magnetic plate 17 in addition to winding a conductive wire MAG-89-164 of the Society for Magnetics Research Group), and as shown in FIG. 12, a U-shaped conductor 18 is printed on a magnetic sheet 19 and the U-shaped conductors are stacked in alternate directions. After that, the laminated chip inductor 20 (actually developed 57-
No. 100209).

However, in the case of the above-mentioned micro magnetic core 15 and multilayer chip inductor 20, the accuracy of the inductance value is poor and the inductance value cannot be finely adjusted because the actual inductance value cannot be known until it is completed.

Further, in the case of the micro magnetic core 15, since the thinning technique is used for the purpose of downsizing, a large inductance value cannot be obtained and a large current cannot flow. Further, in the case of the multilayer chip inductor 20, there is a problem that the magnetic core is saturated because a closed magnetic circuit is structurally formed, and a large current cannot flow.

Further, as a thin coil device, a distributed constant type inductor 21 as shown in FIG. 13 in which a plurality of conductive fibers 22 and a plurality of magnetic fibers 23 are alternately braided.
(Jpn. Pat. Appln. KOKAI HEI 6-2250), braided cross inductor (Journal of Japan Applied Magnetics, Vol.9, No.2, 1985, P2)
55-258) is known.

However, in the above-described coil device in which the plurality of conductive fibers 22 and the plurality of magnetic fibers 23 are braided in an alternating or net-like manner, the inductance can be finely adjusted, but the magnetic substance is a metal fiber. Therefore, there is a problem that it is easy to saturate, and the conductors are easily short-circuited via the magnetic material, so that a large current cannot flow.

[0010]

From the above-mentioned conventional examples, the conventional coil device in which the E-shaped core corresponding to the large inductance and the large current is combined has a problem in thinning, and it is difficult to reduce the thickness. A coil device that can deal with the problem has a problem that it cannot deal with a large inductance and a large current.

The present invention has been made in consideration of the above problems, and an object thereof is to provide a thin coil device having a large inductance and capable of flowing a large current.

[0012]

To achieve the above object, a coil device according to a first aspect of the present invention comprises a plurality of plate-shaped or rod-shaped ferrites arranged in parallel with each other with a predetermined space (d) therebetween. It has a conductor wire which is sewn in a wave shape and wound between predetermined intervals of these ferrites.

In the coil device according to the second aspect, the length (l) of the plate-shaped or rod-shaped ferrite in the longitudinal direction and the longer width or outer diameter (of the plane perpendicular to the magnetization direction of the ferrite ( It is characterized in that the ratio (l / a) to a) is greater than 0 and 50 or less.

Further, in the coil device according to the third aspect, the ratio (a / d) between the width or outer diameter (a) of the ferrite and the predetermined interval (d) between the ferrites is 1 or more and 100 or less. It is characterized by.

[0015]

According to the coil device of the present invention, a conductor wire is sewn in a wavy shape between a plurality of plate-shaped or rod-shaped ferrite elements that are arranged in parallel with each other at a predetermined interval, and the conductor wire is wound around the conductor wire. Allows a large current to flow.

According to the coil device of the second aspect, the ratio (l / a) of the length (l) of the plate-shaped or rod-shaped ferrite to the width or outer diameter (a) of the ferrite is 50 or more. If this is set, the diamagnetic field coefficient of ferrite becomes too small, and the frequency characteristic deteriorates. Therefore, the large inductance cannot be obtained, and this is prevented.

According to another aspect of the coil device of the present invention, when the ratio (a / d) between the width or outer diameter (a) of the ferrite and the predetermined spacing (d) between the ferrites is less than 1, This is prevented because the resistance becomes too large and a large inductance cannot be obtained, and when it is more than 100, the magnetic resistance becomes too small and the magnetic circuit becomes a closed magnetic circuit and a large current cannot flow.

[0018]

EXAMPLES Examples of the present invention will be described in detail below.

A coil device 1 of the first embodiment shown in FIG.
Has five plate-shaped ferrites 2 arranged at a predetermined interval in parallel with each other, and a conductive wire 3 wound in a wave shape between the predetermined intervals of these ferrites 2. is there.

All the ferrites 2 have a length 1 in the longitudinal direction of 66 mm and a width a in the winding direction of 5 mm.
Two external ferrites (2A, 2
E) and three internal ferrites (2B, 2C, 2D) having a width a in the winding direction of 10 mm and arranged inside. That is, the internal ferrite (2B, 2C, 2D) has twice the cross-sectional area in the winding direction as compared with the external ferrite (2A, 2E). This is as shown in FIG.
This is because the effective value of the magnetic flux 6 of the external ferrite (2A, 2E) is about half that of the internal ferrite (2B, 2C, 2D). That is, even if all the five plate-shaped ferrites 2 have the same shape as the internal ferrites (2B, 2C, 2D), there is no great difference in characteristics.

The distance d between the ferrites 2 is 1 m.
m, internal ferrite (2B, 2C, 2D)
The ratio (10 in the first embodiment) to the width a is an optimum value for obtaining a large inductance in the coil device 1 and allowing a large current to flow.

The thickness b1 of the ferrite 2 shown in the top view of FIG. 2 is 3.6 mm, and the total thickness c1 of the coil device 1 including the wound conductor wire 3 is 4.6 mm.
Has become.

The conductive wire 3 is of a general-purpose type having an insulating coating, and is not directly wound around the ferrite 2 but is sewn alternately with a predetermined space provided between the ferrites 2. The outer ferrites (2A, 2E) arranged at both ends are folded back and wound, and the respective ferrites 2 are connected in a comb shape.

Next, the operation of the first embodiment having the above construction will be described with reference to FIG. This coil device 1 is shown in FIG.
It is assumed that a direct current having a current direction 4 as shown in FIG. A current flows from left to right on the front surface of the outer ferrite 2A at the left end and from right to left on the back surface of the paper, and the magnetization direction 5A is substantially coiled around the outer ferrite 2A at the left end. Equivalent to, from bottom to top. For the internal ferrite 2B next to the right, the right to left on the surface of the paper,
A current flows from the left to the right on the back surface of the paper, and the magnetization direction 5B is substantially from the top to the bottom, which is the same as when the solenoid is wound around the ferrite 2. Similarly, thereafter, each ferrite 2 has an upward magnetization direction 5A and a downward magnetization direction 5A.
B will be given alternately.

Next, let us consider what kind of magnetic flux 6 is generated in the coil device 1 by the magnetizations in the mutually opposite directions. As shown in FIG. 4, since the ferrites 2 are close to each other, the magnetic flux 6 from each ferrite 2 flows into the adjacent ferrite 2 through the gap between the ferrites 2. At this time, the magnetic flux 6
Rather than flowing from the coil device 1 through the outside space,
Since it is much easier to flow into the adjacent ferrite 2 (the magnetic resistance is small), the amount of leakage to the outside of the coil device 1 is small. After all, most of the magnetic flux 6 flows so as to draw a loop through the gap between the ferrites 2 as shown in FIG. Since such a flow of the magnetic flux 6 is equivalent to a proper gap being inserted in a magnetic circuit, the coil device 1 has a general-purpose core shape with a proper gap (for example, an E-shaped cross section or a U-shaped cross section). Type) can have almost the same characteristics.

From the flow of the magnetic flux 6 as described above,
As shown in Fig. 4, external ferrites (2
A, 2E) has internal ferrite (2B, 2C, 2D)
Only about half of the magnetic flux 6 will flow. Therefore, even if the width a of the outer ferrites (2A, 2E) arranged at both ends is set to about half of that of the inner ferrites (2B, 2C, 2D), there is not much influence on the characteristics.

Next, in order to confirm to what extent a large current can be applied to the coil device 1 of the first embodiment, a conventional coil using a core shape (EE33 / 47) shown in FIG. The example which evaluated the direct-current superposition characteristic of the apparatus 10 and the coil apparatus 1 of a 1st Example is shown.

First, Table 1 shows a conventional coil device 1 having substantially the same characteristics as the coil device 1 used in the first embodiment.
This is a comparison with 0. In the table, the conventional coil device 10 has a shape in which E-shaped cores are combined.

The first embodiment is constructed as described above, the thickness b1 of the ferrite 2 is 3.6 mm, and the total thickness c1 of the coil device 1 including the winding 3 is m.
It has become m. On the other hand, in the conventional coil device 10 whose top surface is shown in FIG. 9, the thickness b3 of the E-shaped core is 7.5 m.
m, the total thickness c3 including the bobbin and the winding 13 is 2
It is 0 mm.

[0030]

[Table 1]

The two types of ferrites 2 used in the coil device 1 of the first embodiment, the internal ferrites (2B, 2C, 2D) and the external ferrites (2A, 2E), have the magnetic flux 6 as shown in FIG. Therefore, the effective cross section is almost the same. However, in the ferrite 2 of the first embodiment used in this experiment, the magnetic path length obtained by assuming that the ferrite 2 can be effectively regarded as a U core is about 30% longer. Therefore, the weight of ferrite 2 is
The weight of the first embodiment is about 5 g. Of course,
It is possible to make the core weight the same by adjusting the magnetic path length. However, in the case of the first embodiment, since the magnetic flux 6 flows as shown in FIG. 4, the actual magnetic path length is shorter than that when it is considered as the U core.

Further, from Table 1, the coil device 1 of the first embodiment is the same as the conventional coil device 10 using a general-purpose core shape (EE33 / 47) corresponding to large current, large voltage and large inductance. Large inductance equivalent to the number of turns (about 2
It can be seen that mH) has been realized.

FIG. 5 shows the results of measuring the DC superposition characteristics of the coil device 1 of the first embodiment having the above characteristics and the conventional coil device 10.

From this DC superposition characteristic, the coil device 1 of the first embodiment has a large inductance value and
It can be seen that it is possible to flow a large current that is substantially equal to that of the conventional coil device 10.

According to the coil device 1 of the first embodiment described above, the E-type or U-type magnetic core having a transverse cross section, which has been conventionally used, is not required, and the coil device 1 can be constituted only by the plate-shaped or rod-shaped ferrite 2. Therefore, the ferrite 2 can be easily manufactured. Further, the coil device 1 can be easily thinned by simply using the thin plate-shaped ferrite 2.

Further, by combining the plate-like or rod-like ferrites 2 having a large demagnetizing field coefficient at proper intervals, this interval can be effectively utilized as a gap,
It is possible to provide the coil device 1 that is strong in saturation (capable of flowing a large current) and has a small leakage magnetic flux to the outside. Further, by using the oxide magnetic ferrite 2 having a high specific resistance as the magnetic body, it is possible to prevent short-circuiting between the windings, and thus the coil device 1 for a large voltage.
Can be provided.

The coil device 1 having a large inductance can be provided by arbitrarily selecting the type and shape of the ferrite 2 and the spacing between the ferrites 2.

FIG. 6 shows a coil device (transformer) 7 according to a second embodiment of the present invention.

The transformer 7 is composed of three plate-shaped ferrites 2 arranged in parallel with each other with a predetermined space therebetween, and 2 wound by winding a wave between the predetermined spaces of the ferrites 2. It has a lead wire (3A, 3B).

All of the ferrites 2 have a length l of 66 m.
m, the width a in the winding direction is 10 mm.

The thickness b2 of the ferrite 2 is 3.6 m.
m, the total thickness c2 of the transformer 7 including the two wound conductor wires (3A, 3B) is 4.6 mm (see FIG. 7). This makes it possible to reduce the thickness to c3 (20 mm) when the conventional coil device 10 formed by combining the E-shaped cores shown in FIG. 8 is used as a transformer.

The distance d between the ferrites 2 is 1 m.
The two conductors (3A, 3B) of m are bundled and wound on the ferrite 2 at the same time.

The number of conductors 3 is not limited to two, and three or more conductors may be wound at the same time, and each conductor may be wound when the target winding ratio is reached. .

Table 2 shows the characteristics of the transformer 7 of the second embodiment. As shown in this table, the coupling coefficient showing the performance as the transformer shows the highest value of 1, and it is understood that the transformer has excellent characteristics.

[0045]

[Table 2]

According to the transformer 7 of the second embodiment described above, in addition to the effect shown in the first embodiment, the transformer 7
It is possible to make it thin, and each ferrite 2
Since the bifilar winding can be performed without worrying about the insulation between them, it is possible to provide the transformer 7 having a very good coupling property.

The present invention is not limited to the above-mentioned embodiments, but various modifications can be made.

For example, the plurality of ferrites 2 arranged in parallel with each other with a predetermined gap therebetween is not limited to the case of arranging them in one horizontal row, but an arbitrary array (for example, zigzag or circular) as shown in FIGS. 14 and 15. You may

In such a case, there is an effect that it can be formed in an arbitrary shape depending on the place where the coil device is mounted.

[0050]

The coil device according to claim 1 of the present invention, which has been described in detail above, does not require a magnetic core having an E-shaped or U-shaped cross section, which is conventionally used, and has a plate-like or rod-like shape. Since it can be composed of only ferrite, it can be easily thinned.
Further, by using a ferrite of an oxide magnetic material having a high specific resistance as the magnetic material, it is possible to prevent short-circuiting between the windings, and it is possible to provide a coil device compatible with large voltage.

Further, according to the coil device of the second aspect, it is possible to obtain a large inductance by preventing the diamagnetic field coefficient from becoming too small, and further to stabilize the frequency characteristic.

According to the coil device of the third aspect, the coil device having a large inductance and capable of flowing a large current can be provided by freely selecting the interval between the ferrites within a predetermined range. be able to.

[Brief description of drawings]

FIG. 1 is a front view showing a first embodiment of a coil device of the present invention.

FIG. 2 is a top view of the first embodiment.

FIG. 3 is an explanatory view of the operation of the first embodiment.

FIG. 4 is an explanatory view showing the flow of magnetic flux of the first embodiment.

FIG. 5 is a comparison diagram of DC superposition characteristics of the first embodiment and the conventional coil device.

FIG. 6 is a front view showing a second embodiment of the coil device of the present invention.

FIG. 7 is a top view of the second embodiment.

FIG. 8 is a front view of a conventional coil device (EE33 / 47).

FIG. 9 is a top view of a conventional coil device (EE33 / 47).

FIG. 10 is a top view of a coil device in which a conventional core is flattened to be thin.

FIG. 11 is a front view of a conventional micro magnetic core including a zigzag folded sheet coil.

FIG. 12 is a side view of a conventional multilayer chip inductor.

FIG. 13 is a front view of a conventional distributed constant type inductor using conductive fibers and magnetic fibers.

FIG. 14 is a top view showing another embodiment of the present invention.

FIG. 15 is a top view showing another embodiment of the present invention.

[Explanation of symbols]

 1 Coil device 2 Ferrite 3 Conductor

Claims (3)

[Claims] 1. A plurality of plate-shaped or rod-shaped ferrites arranged at a predetermined interval (d) in parallel with each other, and wound by winding a wave between the predetermined intervals (d) of these ferrites. And a conductive wire that has been formed. 2. The ratio of the length (l) in the longitudinal direction of the plate-shaped or rod-shaped ferrite to the longer width or outer diameter (a) of the plane perpendicular to the magnetization direction of the ferrite (l / a) is
The value is greater than 0 and 50 or less.
The described coil device. 3. The width or outer diameter (a) of the ferrite,
Ratio (a / d) to the predetermined spacing (d) between ferrites
Is 1 or more and 100 or less, The coil device according to claim 1 or 2 characterized by things.