JPH11186086A - Manufacture of spiral coil for noncontact power transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the manufacture of a spiral coil which is high in dielectric breakdown strength. SOLUTION: A laminate (plywood) is manufactured by laminating a flexible metallic plate 310 and a flexible insulating member 311 of a specified thickness through bonding. Then, the laminate (plywood) is wound into a roll form, and the object wound in roll form is fixed through thermal welding or bonding, so that it does no come loose. Thereafter, this fixed object may be out into specified thickness (height). As a result, a spiral coil 30 is manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a spiral coil used in a non-contact power transmission device.

[0002]

2. Description of the Related Art As this kind of non-contact power transmission device,
The present applicant has already proposed a “contactless charger” capable of contactlessly charging a secondary battery (see, for example, Japanese Patent Application Laid-Open No. 7-231,586). In this non-contact charger, electric power is transmitted from a power transmission side to a power reception side in a non-contact manner using an electromagnetic induction effect.

FIG. 2 shows a conventional non-contact power transmission device. 2A is a cross-sectional view of the non-contact power transmission device, and FIG. 2B is a plan view of a power transmission unit. The illustrated non-contact power transmission device includes a power transmission unit 10 and a power reception unit 20 that are opposed to each other with a predetermined distance d therebetween.
This is a device for transmitting power from 0 to the power receiving unit 20 in a non-contact manner.

The power transmission unit 10 includes a power transmission side soft magnetic material 11 and a plurality (two in the illustrated example) of power transmission side spiral coils 12 and 13 mounted on the power transmission side soft magnetic material 11. .
Similarly, the power receiving unit 20 includes a power receiving side soft magnetic material 21 and a plurality of (two in the illustrated example) power receiving side spiral coils 22 and 23 mounted on the power receiving side soft magnetic material 21. . Ferrite is used as the soft magnetic material.

In the power transmission section 10, the power transmission side spiral coils 12, 13 are wound so that the directions of magnetic fluxes generated are opposite to each other, and are connected in series. One end of each of the power transmission-side spiral coils 12 and 13 is connected to an AC power supply (for example, a commercial AC power supply) 15 as illustrated. In the power receiving unit 20, the power receiving side spiral coil 2
The power transmission side spiral coils 12, 1 are disposed opposite to the power transmission side spiral coils 12, 13, respectively.
The coils are wound so that the directions of the currents generated by the change in the magnetic flux generated in step 3 are the same, and are connected in series.

In the non-contact power transmission device having such a configuration, the power transmitted from the power transmitting unit 10 to the power receiving unit 20 is determined by the magnitude of the magnetic flux and the distance d. That is,
The greater the magnetic flux, the greater the transmitted power and the distance d
Is shorter, the transmitted power is larger. The magnitude of the magnetic flux is determined by the current flowing through the spiral coil and the number of turns. That is, the larger the current, the larger the magnetic flux,
The larger the number of turns, the larger the magnetic flux. Therefore, in order to increase the transmitted power, the distance d is short, the number of turns is large,
What is necessary is just to make the electric current which flows large.

FIG. 2B shows the direction of the magnetic flux when the current I flows in the direction of the arrow in the figure. That is, "○
The symbol "x" in the symbol indicates the direction of the magnetic flux downward from above the plane of the paper, and the symbol "in the circle" indicates the direction of the magnetic flux upward from below the plane of the paper. The direction of the magnetic flux is indicated by the arrow A in FIG.

In the non-contact power transmission device having such a configuration, assuming that a current I as shown in FIG. 1 is applied to the power transmission side spiral coils 12, 13 of the power transmission section 10, the power transmission side spiral coils 12, The magnetic flux A generated in the power transmission side spiral coil 12 → the power transmission side soft magnetic material 11 → the power transmission side spiral coil 1
3 → the power receiving side spiral coil 23 → the power receiving side soft magnetic material 21 → the power receiving side spiral coil 22 → the power transmitting side spiral coil 12, so that the magnetic flux leaks to the outside because it passes through the closed magnetic path. Can be prevented. Therefore, even if the electronic component is arranged close to the power receiving side soft magnetic material 21, the electronic component is not heated by the magnetic flux.

FIG. 3 shows a conventional spiral coil 30 'used in the non-contact power transmission device. In FIG.
(A) is a plan view and (b) is a cross-sectional view. The conventional spiral coil 30 'is manufactured by spirally winding a wire 31'. As shown in FIG. 3B, a round wire having a circular cross section is used as the wire 31 '. doing. A self-bonding wire is used as the wire (round wire) 31 '. Here, the “self-fusion wire” refers to the copper wire 310.
′ Is coated with an insulating film 311 ′
′ Is covered with a self-fusion layer (not shown).

As described above, in the conventional non-contact type power transmission device, a wire (circular wire) 31 ′ having a circular cross section is used as the spiral coil 30 ′ used in the power transmission device. However, there is a problem that the inductance value of the spiral coil 30 'cannot be increased because of the large step size and the poor step factor.

[0011] In order to solve such a problem, the present inventors, on September 22, 1997, as shown in FIG.
An application using a rectangular wire 31 ″ having a rectangular cross section as the wire material of the spiral coil 30 ″ has been filed (Japanese Patent Application No. 9-2).
No. 56,747). In FIG. 4, (a) is a plan view,
(B) is a sectional view. The illustrated spiral coil 30 "
The wire 31 "is manufactured by spirally winding the wire 31", and as shown in FIG. 4B, a rectangular wire having a rectangular cross section is used as the wire 31 ". As the wire (square wire) 31 ″, a self-bonding wire is used as in the conventional case.

For example, as shown in FIG. 4, a wire (a rectangular wire) 31 ″ having a width (length of a short axis) r and a height (length of a long axis) of π · r is used as a wire (a rectangular wire) 31 ″. That is, the long axis direction of the wire 31 "is extended in a direction perpendicular to the plane on which the spiral coil 30" is wound. Of the round line 31 '. However, since the width r of the flat wire 31 ″ is half the width 2r of the round wire 31 ′, the number of turns wound on the same area can be twice as large as the round wire 31 ′. Although the distance d between the power transmitting unit 10 and the power receiving unit 20 is slightly longer than the conventional one, the number of turns is doubled, so that the magnetic flux can be increased, and as a result, the power that can be transmitted is increased as compared with the conventional one. be able to.

As described above, by making the cross-sectional shape of the wire 31 "constituting the spiral coil 30" rectangular, the space factor can be improved, the winding can be efficiently performed, and the inductance value can be increased. it can. Conversely, when the magnitude of the magnetic flux is the same as that of the round wire 31 ′, the rectangular wire 31 ″ can reduce the current in a circuit, and consequently reduce the copper loss. Can be done.

[0014]

However, like the round wire 31 ', the rectangular wire 31 "is also a copper wire 310" covered with an insulating film 311 ". The insulating film 311"
Has a thickness of 50 to 100 μm and is very thin. The spiral coil 30 "manufactured by spirally winding the rectangular wire 31" into a coil shape has a withstand voltage (dielectric withstand voltage between the adjacent rectangular wires 31 ") of the rectangular wire 31". Is defined by the thickness of the insulating film 311 "of the flat wire 31". As described above, since the thickness of the insulating film 311 "of the flat wire 31" is thin, the spiral coil 30 "is formed.
It is difficult to improve the withstand voltage of these.

Therefore, an object of the present invention is to provide a method of manufacturing a spiral coil having a high withstand voltage.

[0016]

According to the present invention, there is provided a method for manufacturing a spiral coil used in a non-contact type power transmission device, comprising: a flexible metal plate and a flexible metal plate having a predetermined thickness. For a non-contact power transmission device, comprising: a step of bonding an insulative insulating member, and a step of winding the bonded article into a roll, and a step of fixing the rolled article so as not to be unwound. A method of manufacturing a spiral coil is obtained.

[0017]

The spiral coil is made of a flexible metal plate and a flexible insulating member having a predetermined thickness, which are wound in a roll, so that the insulation between the metal plates adjacent to each other is obtained. The withstand voltage (dielectric withstand voltage between layers) is defined by the thickness of the insulating member interposed between them. Therefore,
The greater the thickness of the insulating member, the higher the dielectric strength between layers can be increased. Therefore, it becomes possible to easily design and manufacture a spiral coil having a withstand voltage of an arbitrary height.

[0018]

Next, the present invention will be described in detail with reference to the drawings.

The basic structure of the non-contact power transmission device according to the present invention is the same as that shown in FIG. 2, and the difference from the conventional one lies in the method of manufacturing the spiral coil used therein. Therefore, only the method of manufacturing the spiral coil will be described below, and the description of the non-contact power transmission device will be omitted.

Referring to FIG. 1, a method of manufacturing a spiral coil according to an embodiment of the present invention will be described.

First, as shown in FIG. 1A, a flexible metal plate 310 and a flexible insulating member 311 having a predetermined thickness t are prepared (prepared). In the present embodiment,
Although a copper plate or a copper foil is used as the flexible metal plate 310, another metal material may be used. Further, as the insulating member 311, a resin material such as a polyimide resin or a polyamide resin is used. Then, the insulating member 31
It is preferable to use a thickness t in the range of 0.1 to 1.0 mm. If the thickness t is less than 0.1 mm, it becomes difficult to secure a necessary withstand voltage, and if the thickness t is more than 1.0 mm, processing becomes difficult.

Next, as shown in FIG. 1B, a flexible metal plate 310 and a flexible insulating member 311 are bonded by bonding to produce a bonded product (plywood).

Then, as shown in FIG. 1 (c), the bonded product (plywood) is wound into a roll, and the rolled product is fixed by heat welding or bonding so as not to be unraveled. Thereafter, the fixed object may be cut to a predetermined thickness (height). Thereby, the spiral coil 30 is manufactured.

Since the spiral coil 30 is manufactured in this manner, the spiral coil 30 is manufactured by changing the cutting width arbitrarily.
Can be set to an optimum thickness. Also, the metal plate 310
If the thickness is reduced, the skin effect can be suppressed, and there is an advantage that the high frequency characteristics are improved. Since the insulating member 311 has a predetermined thickness t, the adjacent metal plate 3
It is possible to increase the withstand voltage between 10 layers (interlayer). As described above, since the spiral coil 30 has a high interlayer withstand voltage, it is suitable for a large current (high power), and is suitable, for example, as a resonance coil constituting a non-contact charger for an electric vehicle. In other words, a spiral coil 30 having a high withstand voltage (several kV) suitable for a voltage resonance system such as a large power transmission can be obtained. In addition, by using the same material as that used for the printed circuit board or the like as the insulating member 311, the dielectric strength between layers, high-frequency characteristics, and heat-resistant blade can be improved.

Although the preferred embodiments of the present invention have been described above as examples, the present invention is not limited to the above-described embodiments, and various changes can be made without departing from the scope of the present invention. Needless to say. For example, the number of turns of the spiral coil is not limited to the above-described embodiment. Needless to say, the thickness t of the insulating member 311 can be arbitrarily selected depending on a desired withstand voltage.

[0026]

As described above, according to the present invention, a flexible metal plate and a flexible insulating member having a predetermined thickness are bonded to each other and fixed in a roll shape.
Since the spiral coil is manufactured, the withstand voltage between the metal plates adjacent to each other (the withstand voltage between layers) is determined by the thickness of the insulating member interposed therebetween. Therefore, as the thickness of the insulating member is increased, the withstand voltage between layers can be increased. Therefore, it becomes possible to easily design and manufacture a spiral coil for high power transmission having an arbitrary withstand voltage and a high withstand voltage.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a manufacturing process of a spiral coil according to an embodiment of the present invention.

FIGS. 2A and 2B are diagrams illustrating a schematic configuration of a conventional non-contact power transmission device, where FIG. 2A is a cross-sectional view and FIG. 2B is a plan view of a power transmission unit.

3A and 3B are diagrams showing a spiral coil used in a conventional non-contact power transmission device, wherein FIG. 3A is a plan view and FIG. 3B is a cross-sectional view.

FIG. 4 is a diagram showing a spiral coil used in the non-contact power transmission device according to the prior application, which has been already filed by the present inventors,
(A) is a plan view and (b) is a cross-sectional view.

[Explanation of symbols]

 Reference Signs List 30 spiral coil 310 flexible metal plate 311 flexible insulating member

Claims (7)

[Claims] 1. A method of manufacturing a spiral coil used in a non-contact power transmission device, comprising: bonding a flexible metal plate and a flexible insulating member having a predetermined thickness. A method of manufacturing a spiral coil for a non-contact power transmission device, comprising: a step of winding the bonded product in a roll shape; and a step of fixing the rolled product so as not to be unwound. 2. The flexible metal plate is a copper plate.
A method for manufacturing a spiral coil for a non-contact power transmission device according to claim 1. 3. The flexible metal plate is a copper foil.
A method for manufacturing a spiral coil for a non-contact power transmission device according to claim 1. 4. The method for manufacturing a spiral coil for a non-contact power transmission device according to claim 1, wherein the predetermined thickness is in a range of 0.1 to 1.0 mm. 5. The method for manufacturing a spiral coil for a non-contact power transmission device according to claim 1, wherein the fixing step fixes the rolled object by heat welding. 6. The method for manufacturing a spiral coil for a non-contact power transmission device according to claim 1, wherein the fixing step fixes the rolled object by bonding. 7. The method for manufacturing a spiral coil for a non-contact power transmission device according to claim 1, further comprising, after the fixing step, a step of cutting the fixed object to a predetermined thickness.