JP2021034707A - High-frequency coil component, coil component for wireless power supply, wireless power supply device, and manufacturing method of frequency coil component - Google Patents

Abstract

To provide a high-frequency coil component that can be manufactured at a low cost by reducing high-frequency losses due to a proximity effect of the high-frequency coil and suppressing an increase in AC resistance, and to provide a wireless power supply device with high transmission efficiency using the transmission coil component.SOLUTION: The high-frequency coil component has a coil conductor 10 wound in a spiral shape, a storage case 12 made of non-magnetic insulating material having a groove 15 formed in a shape that follows the shape of the coil conductor 10 for storing the coil conductor 10, and a magnetic layer 11 in which magnetic material is provided between the coil conductor 10 stored in the groove 15 and the inner wall of the groove 15.SELECTED DRAWING: Figure 2

Description

The present invention relates to a high frequency coil component and a method for manufacturing the same. Further, the present invention relates to a wireless power supply device (contactless power supply device) using the same.

In recent years, the use of electromagnetic induction type or magnetic resonance type wireless power feeding devices has been studied for charging batteries of vehicles such as electric vehicles and hybrid vehicles. In a wireless power feeding device, a high-frequency alternating current (generally several tens of kHz to 200 kHz) is energized in a power transmission coil, and the power receiving coil receives a high-frequency magnetic field generated from the power transmission coil to transmit power wirelessly.

In such a wireless power feeding device, a spiral-shaped (spiral-shaped) flat coil is used in response to the thinning of the device. Further, in order to avoid leakage of the surrounding magnetic field due to the high frequency magnetic field, a magnetic shield such as ferrite is arranged near the coil (for example, Patent Document 1). The high frequency coil component (coil component for non-contact power supply) is composed of a combination of a flat coil and a magnetic shield.

In a high-frequency coil component, when a high-frequency alternating current is applied to the coil, a magnetic flux line is generated so as to surround the coil conductor. This magnetic flux line acts on the conductor itself, and a skin effect in which the current is concentrated on the surface of the conductor appears, and there is both a proximity effect due to an eddy current generated in the coil conductor adjacent to the skin effect. The AC resistance caused by this skin effect and proximity effect increased, and the wire loss also increased. Therefore, the AC resistance increases, and the decrease in power transmission efficiency becomes a problem.

To solve this problem, it is known to use a litz wire obtained by twisting a large number of thin insulating wires as a coil winding (for example, Patent Document 2). The litz wire is a wire obtained by combining a large number (for example, 1000 or more) of thin strands (for example, enamel wire having a diameter of 0.1 mm or less). It is possible to suppress high frequency loss due to the skin effect and proximity effect.

A magnetically plated wire in which the surface of a single wire is magnetically plated has been proposed (for example, Patent Document 3). The magnetically plated wire is formed by forming a magnetic layer (iron thin film) on the outer circumference of the copper wire by plating. Further, a magnetically coated wire in which a mixture of a magnetic powder and a solvent (magnetic composite material) is coated on the outer surface of the lead wire has been proposed (Patent Document 4). Alternatively, there is also a coating method using a magnetic spray (Patent Document 5). By applying a magnetic material to the conductors described above, it is possible to suppress the magnetic field generated by the current flowing through the adjacent conductors from entering the conductor, suppress the generation of eddy currents in the conductors, and reduce the AC resistance.

Japanese Unexamined Patent Publication No. 2013-201296 Japanese Unexamined Patent Publication No. 2016-219252 Japanese Unexamined Patent Publication No. 4-214896 Japanese Unexamined Patent Publication No. 2014-71969 Japanese Unexamined Patent Publication No. 2018-137120

In any of the above-mentioned methods of adhering a magnetic material to a conducting wire, the adhering process is complicated, and manufacturing time and cost are required. In addition, the magnetic layer is damaged by a process such as bending after the magnetic material is attached. Therefore, in view of the above circumstances, the present invention can be manufactured at low cost and has high efficiency by reducing the high frequency loss (copper loss) due to the skin effect and proximity effect peculiar to the flat plate spiral coil to suppress the increase in AC resistance. The purpose is to provide high frequency coil parts. Another object of the present invention is to provide a wireless power feeding device having high transmission efficiency using this transmission coil component.

The high-frequency coil component of the first invention is made of a non-magnetic insulating material having a coil wire wound in a spiral shape and a groove formed in a shape along the shape of the coil wire for accommodating the coil wire. It is characterized by having a storage case and a magnetic layer formed by providing a magnetic material between the coil conducting wire housed in the groove and the inner wall of the groove.

The high-frequency coil component of the second invention is characterized in that the magnetic layer is provided over a part or the entire circumference of the coil conducting wire.

In the high-frequency coil component of the third invention, the coil lead wire is made of copper or aluminum or an alloy thereof, and the cross-sectional shape of the coil lead wire is circular, elliptical, square or polygonal, and one piece. It is characterized by being a single wire or a stranded wire or a litz wire twisted by a plurality of conductors.

In the high-frequency coil component of the fourth invention, the coil conductors wound in a spiral shape are wound with the coil conductors wound at a certain interval, and at least a part of the coil conductors are wound between the intervals. It is characterized by the presence of storage case walls or other insulating material.

The high-frequency coil component of the fifth invention is characterized by including a magnetic shield made of a magnetic material arranged so as to face the coil surface of the coil conducting wire, and an electric shield made of a conductor.

The high-frequency coil component of the sixth invention uses the high-frequency coil component according to any one of the above 1 to 5 as a wireless power feeding coil component and a power receiving coil, and a wireless power feeding coil component using the same. There was a wireless power supply device.

The method for manufacturing a high-frequency coil component of the seventh invention is a step of manufacturing a coil wire wound in a spiral shape by bending the coil wire, and a step of manufacturing the coil wire for accommodating the coil wire. A step of manufacturing a storage case made of a non-magnetic insulating material having a groove formed in a shape conforming to the shape, a step of inserting a magnetic material into the groove, and a step of inserting the coil lead wire into the groove in which the magnetic material is inserted. A method for manufacturing a high frequency coil component, which comprises.

The high-frequency coil according to claim 8, wherein the method for manufacturing a high-frequency coil component of the eighth invention is characterized in that the magnetic material has a solid, liquid, gel-like, powdery, or plastic property. How to manufacture parts.

The method for manufacturing a high-frequency coil component according to a ninth aspect of the present invention according to claim 8, wherein the magnetic material is formed into a flexible film or a shape into which the coil lead wire can be fitted. Manufacturing method of high frequency coil parts.

According to the high-frequency coil component of the present invention, magnetic flux wires concentrated on the surface and side surfaces of the coil conductor are provided between the coil conductor of each winding and the storage case without using a magnetic plating wire or a magnetic coating wire. The number of magnetic flux lines penetrating the coil conductor can be reduced by inducing the magnetic layer. As a result, it is possible to suppress the eddy current in the coil conductor and reduce the AC resistance (copper loss) of the coil, and it is possible to improve the transmission efficiency.

Therefore, the magnetic flux lines are concentrated on the magnetic layer having a low eddy current loss, so that the magnetic flux flowing through the conductor having a large eddy current loss is reduced. Therefore, as a result, the AC resistance of the coil can be reduced.

According to the method for manufacturing a high-frequency coil component of the present invention, the magnetic material is directly provided (filled) in the groove of the storage case, which leads to simplification of the process and improvement of the utilization rate of the magnetic material as compared with the prior art. It is possible to achieve both low cost and high productivity.

Since the magnetic layer made of the magnetic material is inside the storage case, damage due to external force can be prevented. Since the storage case is made of a non-magnetic insulating material such as resin, transmission coil parts can be easily manufactured at low cost.

Conventionally used magnetic plated wires and magnetic coated wires could not be bent, but according to the method for manufacturing high-frequency coil parts of the present invention, since metal wires are used, they are spirally formed by bending. Since it can be processed into a coil lead wire, high frequency coil parts can be manufactured at low cost.

It is a top view of the plane of the transmission coil component which concerns on 1st to 5th Embodiment. It is sectional drawing of the transmission coil component which concerns on 1st Embodiment. It is sectional drawing of the transmission coil component which concerns on 2nd Embodiment. It is sectional drawing of the transmission coil component which concerns on 3rd Embodiment. It is sectional drawing of the transmission coil component which concerns on 4th Embodiment. It is sectional drawing of the transmission coil component which concerns on 5th Embodiment. It is sectional drawing of the transmission coil component which concerns on 6th Embodiment. It is the shape of the wireless power feeding coil of the embodiment of the present disclosure. Measured value of AC resistance of the wireless power feeding coil according to the embodiment of the present disclosure. It is a block diagram explaining the manufacturing method of a high frequency coil component. It is an assembly drawing explaining the manufacturing method of a high frequency coil component.

A high-frequency coil component according to an embodiment of the present invention, a method for manufacturing the same, and a wireless power feeding device using the high-frequency coil component will be described with reference to the drawings.

<1. High frequency coil parts ＞
FIG. 1 is a schematic plan view of a high-frequency coil component according to the first to fifth embodiments. FIG. 2 is a cross-sectional view of it. The high-frequency coil component is a storage case made of a non-magnetic insulating material having a coil lead wire 10 wound in a spiral shape and a groove 15 formed in a shape substantially following the shape of the coil lead wire 10 for accommodating the coil lead wire 10. The structure has a magnetic layer 11 formed by providing (inserting) a magnetic material between the coil lead wire 10 housed in the groove 12 and the inner wall of the groove 15. An insulating layer may be inserted between the coil conductor 10 and the magnetic shield 13.

Since the magnetic layer 11 is formed between the coil lead wire 10 and the inner wall (storage case 12) of the groove 15, the magnetic flux generated when the coil lead wire 10 is energized flows through the magnetic layer 11, and the eddy current loss is low. By concentrating on the magnetic layer 11, the magnetic flux flowing through the coil lead wire 10 having a large eddy current loss is reduced. Therefore, the AC resistance of the coil lead wire 10 can be reduced.

The coil lead wire 10 is made of a metal wire, and specifically, is made of copper, aluminum, or an alloy thereof. The cross-sectional shape of the coil lead wire 10 is circular, elliptical, quadrangular or polygonal. FIG. 2 shows an example in which the cross-sectional shape of the coil lead wire 10 is circular. The coil lead wire 10 is a single wire or a stranded wire or a litz wire twisted by a plurality of lead wires. The figure shows an example in which the coil lead wire 10 is composed of one single wire.

The storage case 12 is made of a non-magnetic insulating material. A material having a heat resistance of 100 ° C. or higher is desirable. The material of the storage case 12 is a non-magnetic, non-insulating material such as a resin, a fiber, or a polymer compound. The storage case 12 is formed in a plate shape, and a groove 15 is formed on one surface (lower surface of FIG. 2).

As shown in the figure, since the magnetic layer 11 is formed between the coil conductor 10 and the inner wall of the groove 15, the size of the groove 15 is larger than the size of the coil conductor 10 and is between the storage case 12 and the coil conductor 10. The size should be such that there is a gap in the wire. Specifically, the size of the groove 15 is determined in consideration of the layer thickness of the magnetic layer 11 and the cross-sectional shape of the coil lead wire 10.

When the cross-sectional shape of the coil lead wire 10 is circular, it is preferable that the bottom portion of the groove 15 is formed in an arc shape corresponding to the shape of the coil lead wire 10. As shown in the figure, the magnetic layer 11 may not be provided over the entire circumference of the coil lead wire 10, and the magnetic layer 11 may be provided on a part around the coil lead wire 10.

The magnetic layer 11 (magnetic material) provided between the coil conductor 10 and the groove 15 (storage case 12) is a powder of an iron-based alloy, an amorphous magnetic powder, an iron oxide, a powder of a magnetic material such as a ferrite material. Or a mixture of it and a fluid binder such as a polymer compound, a resin, or a mineral. The thickness of the magnetic layer 11 is preferably in the range of about 0.01-1 mm.

When the coil conductor 10 is driven by an alternating current, a magnetic shield 13 composed of a magnetic material arranged so as to face the surface of the coil conductor 10 and a conductor such as metal in order to prevent leakage magnetic fields and electric fields generated in the surroundings. It is preferable to provide an electric shield 14 composed of the above. The magnetic shield 13 and the electric shield 14 are the same as those conventionally used, and each is formed in a plate shape (sheet shape). A magnetic shield 13 is joined to the storage case 12 via an insulating material, and an electric shield 14 is joined to the magnetic shield 13 via an intermediate material.

As shown in FIG. 3, the magnetic layer 11 may be provided over the entire circumference of the coil lead wire 10. It is preferable that the magnetic layer 11 is provided over the entire circumference of the coil lead wire 10 rather than being provided on a part of the periphery. The magnetic flux acting on the coil lead wire 10 is reduced, and the AC resistance of the coil can be reduced.
When the magnetic layer 11 is partially provided, the manufacturing process is simplified and the amount of the magnetic material used can be reduced.

In this case, it is preferable that the magnetic layer 11 does not protrude from one surface (lower surface of FIG. 3) of the storage case 12 so as not to interfere with the insulating material bonded under the storage case 12. In order to make the magnetic layer 11 thicker, it is preferable to form the magnetic layer 11 so as to be flush with one surface of the storage case 12.

FIG. 4 shows an example in which the cross-sectional shape of the coil lead wire 10 is square. In this case, it is preferable that the cross-sectional shape of the groove 15 is formed into a quadrangular shape corresponding to the shape of the coil lead wire 10. The size of the 15 grooves is larger than the size of the coil conductor 10, and a gap is formed between the storage case and the conductor. The gap is filled with a magnetic material to form the magnetic layer 11. The magnetic layer 11 may be provided on three sides (part) around the rectangular coil lead wire 10, or may be provided on four sides (entire circumference).

FIG. 5 shows an example in which the coil lead wire 10 is a stranded wire or a litz wire twisted by a plurality of lead wires. By applying the method for manufacturing a high-frequency coil component of the present invention, which will be described later, the magnetic layer 11 can be formed so as to be in close contact with the periphery of the coil lead wire 10 even if it is a stranded wire lead wire. As shown in the figure, it is preferable to provide the magnetic layer 11 in close contact with the entire circumference of the coil lead wire 10. As shown in FIG. 6, the magnetic layer 11 may be provided over a part around the coil lead wire 10. In the case of FIGS. 5 and 6, the case where the litz wire has an insulating coating such as a fiber or a resin film is shown. The litz wire may be uncoated.

As shown in FIGS. 1 to 6, in the coil conductors 10 wound in a spiral shape, the coil conductors 10 are wound with a certain interval, and at least a part of the coil conductors 10 is stored between the intervals. It is preferable that the wall of the case 12 is present. If the wall of the storage case 12 is present, the magnetic layer 11 can be held around the coil conductor 10.

FIG. 7 shows an example in which the magnetic shield 13 and the electric shield 14 are arranged so that the groove 15 of the storage case 12 is arranged on the opposite side of the opening surface. In this case, the magnetic material 11 is prevented from adhering to the magnetic shield 13. In addition, the processing process is simplified. It can also play a role in improving the coupling coefficient of the coil component as compared with the case where the magnetic material 11 is not provided. This arrangement example can be applied even when the coil conductor 10 is a square single wire, a litz wire, or the like.

<3. Manufacturing method of high frequency coil parts ＞
FIG. 10 shows a method for manufacturing the high frequency coil component of the present invention. The method for manufacturing high-frequency coil parts is a step 21 of manufacturing a coil conductor wound in a spiral shape by bending a metal wire, and a shape that follows the shape of the coil conductor for accommodating the coil conductor. A step 22 of manufacturing a storage case made of a non-magnetic insulating material having a formed groove, a step 23 of inserting a magnetic material into the groove, and a step 24 of inserting the coil conductor into the groove in which the magnetic material is inserted. Is included.

Since the spiral coil conductor 10 can be manufactured by bending the metal wire, it can be manufactured easily and at low cost. The coil lead wire 10 can be manufactured by using a conventional winding machine for coil manufacturing. Alternatively, it can be bent by a bending machine or the like.

The storage case 12 can be manufactured by a conventional method such as injection molding, press molding, or shaving. The groove 15 may be formed at the same time when the storage case 12 is manufactured. Alternatively, the groove 15 may be formed by cutting after the storage case 12 is manufactured.

In order to form the magnetic layer 11, a solid, liquid, gel, powder or plastic magnetic material is placed in the groove 15. As the magnetic material, for example, a material obtained by dispersing the above-mentioned magnetic powder in a liquid or gel solvent can be preferably used. As the solvent, for example, silicon resin, elastomer, rubber, polymer material, mineral material and the like can be used. As a filling method, for example, a magnetic material can be uniformly injected with a dispenser or the like.

When the coil conductor 10 is inserted into the groove 15, the magnetic material moves in the groove 15 so as to be appropriately pushed away by the coil conductor 10, and a magnetic layer 11 that adheres to the surface of the coil conductor 10 is formed. Soft materials such as silicone resin and elastomer also have the effect of protecting the coil conductor 10.

When the amount of the magnetic material is increased and the coil conductor 10 is inserted into the groove 15 in order to form the magnetic layer 11 on the entire circumference of the coil conductor 10, the magnetic material 11 drowns on the entire circumference of the coil conductor 10. Alternatively, after the coil conductor 10 is inserted into the groove 15, it can be molded all around by reapplying it to the exposed portion of the coil conductor 10.

When the magnetic material 11 is a hard material, the molded sheet film-like magnetic material 11 is put into the groove 15. Since the magnetic material 11 is flexible, it is fitted between the conductor 10 and the storage case 12. Further, in the case of a hard material in which the magnetic material 11 is formed so as to be fitted around the shape of the coil conductor 10, the magnetic material 11 is first inserted into the groove 15, and then the coil conductor 10 is inserted. Alternatively, the magnetic material 11 is fitted into the coil conductor 10 and then inserted into the groove 15.

FIG. 11 shows an assembly drawing of a high-frequency coil component showing a manufacturing method of the present embodiment. A magnetic material for forming the magnetic layer 11 is put (filled) in the groove 15 of the storage case 12 and placed at the bottom. The coil conductor 10 is fitted into the groove 15 from above. The magnetic shield 13 and the electric field shield 14 are sequentially assembled on the magnetic shield 13.

Since the work of inserting the magnetic material into the groove 15 can be easily performed, the high-frequency coil component can be manufactured easily and at low cost. The high-frequency coil component shown in FIG. 11 can be used as a power transmission coil and a power reception coil for wireless power supply.

FIG. 8 shows a specific structural diagram of the wireless power feeding coil in this embodiment. The size of the coil is 320 mm, the number of turns is 9, the material is aluminum, the cross section is 4.5 mm in length, and the thickness is 2 mm. A magnetic material in which powder of an amorphous iron-based material having a particle size of 50 μm or less and a silicon resin was mixed was filled between the aluminum lead wire and the storage case. An electric shield 14 having a magnetic shield 13 made of a ferrite magnetic material and an aluminum plate facing the coil was provided.

FIG. 9 shows the AC resistance data of the wireless power feeding coil in this embodiment. The AC resistance was measured with an impedance analyzer. In the figure, AP is data when the magnetic layer 11 is not filled, and MCP is data when the magnetic layer 11 is filled. The AC resistance of the coil was reduced from 188 mΩ to 134 mΩ of AP at 85 kHz. The effect of the present invention has been demonstrated.

The high-frequency coil component and wireless power feeding device according to the present invention may be used in electronic devices such as automobiles, mobile phones, and tablets. Further, the high frequency coil according to the present invention may also be applied to an induction heating device or the like. Furthermore, the high frequency coil according to the present invention is not limited to use in an electromagnetic induction type non-contact power feeding device. It may also be applied to a magnetic field resonance type non-contact power feeding device.

1 High-frequency coil component 10 Coil conductor 11 Magnetic layer 12 Storage case 13 Magnetic shield 14 Electric field shield 15 Groove 21 Coil conductor manufacturing process 22 Storage case manufacturing process 23 Magnetic material insertion process 24 Coil conductor insertion process

Claims (9)

A storage case made of a non-magnetic insulating material having a coil wire wound in a spiral shape and a groove formed in a shape conforming to the shape of the coil wire for accommodating the coil wire, and a storage case made of a non-magnetic insulating material, which is housed in the groove. A high-frequency coil component having a magnetic layer formed by providing a magnetic material between the coil lead wire and the inner wall of the groove. The high-frequency coil component according to claim 1, wherein the magnetic layer is provided over a part or the entire circumference of the coil conducting wire. The coil conductor is made of copper or aluminum or an alloy thereof, and the cross-sectional shape of the coil conductor is circular, elliptical, quadrangular or polygonal, and is twisted by one single wire or a plurality of conductors. The high frequency coil component according to claim 2 or 3, wherein the wire is a wire or a litz wire. In the spirally wound coil conductors, the coil conductors are wound with a certain interval between the coil conductors, and at least a part of the wall of the storage case or other insulating material is provided between the coil conductors. The high-frequency coil component according to any one of claims 1 to 3, wherein the high-frequency coil component is present. The invention according to any one of claims 1 to 4, wherein a magnetic shield made of a magnetic material arranged so as to face the coil surface of the coil conducting wire and an electric shield made of a conductor are provided. High frequency coil parts. A wireless power feeding coil component and a wireless power feeding device using the high frequency coil component according to any one of claims 1 to 5, wherein the high frequency coil component is used as a wireless power transmission coil and a power receiving coil. Non-magnetic having a step of manufacturing a coil lead wire wound in a spiral shape by bending the coil lead wire and a groove formed in a shape along the shape of the coil lead wire for accommodating the coil lead wire. Manufacture of a high-frequency coil component including a step of manufacturing a storage case made of an insulating material, a step of inserting a magnetic material into the groove, and a step of inserting the coil lead wire into the groove in which the magnetic material is inserted. Method. The method for manufacturing a high-frequency coil component according to claim 8, wherein the magnetic material is in the form of a solid, a liquid, a gel, a powder, or a plastic. The method for manufacturing a high-frequency coil component according to claim 8, wherein the magnetic material is formed into a flexible film or a shape into which the coil lead wire is fitted.

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