JP2003047180A - Contactless charging device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To charge a rechargeable battery of an electric device in a non-contact manner by electromagnetic induction, prevent a metal piece from abnormally generating heat due to electromagnetic induction heating, and improve safety. It is an object of the present invention to provide a non-contact charging device that can reduce circuit loss, has a simple structure, and can be reduced in size. A contactless charging device in which a secondary coil and a primary coil charge a rechargeable battery by an electromagnetic induction action when an electric device is engaged with a charging stand, wherein a support portion of the charging stand forms a body of the electric device. A primary coil wound around the supporting portion, and a secondary coil wound around the body of the electric device with the longitudinal direction as an axis, and a winding width surface of the primary coil and the secondary coil And a circuit board forming another electric circuit including a rectifier of the electric device is provided substantially in the center of the secondary coil in parallel with the winding axis.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging device for a rechargeable battery (secondary battery) incorporated as a power source for a rechargeable electric device. More specifically, the present invention relates to a non-contact type charging device that does not have a connection terminal between a charged part (rechargeable electric device) including a rechargeable battery and a charging stand and that supplies power to the rechargeable battery contactlessly by electromagnetic induction.

TECHNICAL FIELD OF THE INVENTION

[0002]

2. Description of the Related Art In recent years, rechargeable electric devices such as electric toothbrushes, mobile phones, cordless phones, etc. (hereinafter referred to as "rechargeable electric devices" using rechargeable batteries (secondary batteries) that can be repeatedly charged (hereinafter referred to as "electronic devices") The use of electrical equipment) is expanding. And to charge the rechargeable battery,
Generally, a contact-type charging device is used, but there is a possibility that the contact terminals may be oxidized due to surface oxidation or corrosion, resulting in contact failure. On the other hand, in the non-contact type charging device, since the contact terminal is not exposed on the surface, contact failure due to surface oxidation or corrosion of the contact terminal can be prevented, or the contact terminal is not directly touched by a person. Its use is expanding because it is safe.

FIG. 5 shows a partial sectional view of a conventional non-contact type charging device. As shown in FIG. 5, 20 is an electric device, 22
Is a secondary coil on the charged side of the electric device, 20a is a bottom surface of the electric device, 25 is a charging stand, 26 is a primary coil on the charging side,
Reference numeral 25a is a receiving portion that receives the bottom surface 20a of the electric device.
The electric device 20 has an electronic circuit that has a function as an electric device, and is provided with a rechargeable battery that can be repeatedly charged as a power source of the electronic circuit and a charging circuit (not shown). Inside the bottom portion 20 a of the electric device 20, a secondary coil 22 for charging a rechargeable battery is provided on an insulating substrate 21. A circuit board for forming a circuit for charging the rechargeable battery and other electric circuits is provided separately from the board 22 for the secondary coil. In the charging stand 25, a primary coil 26 is provided inside a receiving portion 25a that supports an electric device so as to face the winding surface of the secondary coil 21 of the electric device.

FIG. 6 is an enlarged sectional view of the receiving portion 25a of the charging stand and the primary coil 26. The primary coil 26 has a winding 28 wound around a T-shaped core 27 and is installed inside the receiving portion 25a of the charging stand. In such a contactless type charging device, when a metal piece 30 such as a paper clip or a coin is placed on the upper surface of the receiving portion 25a of the charging stand, the magnetic flux φ generated in the primary coil 26 is perpendicular to the metal piece 30. Because they are linked to each other, a short-circuit current (eddy current) flows through the metal piece and heat is generated. As a countermeasure against this, as shown in FIG.
There is a method of inclining the receiving portion 30a (including the primary coil 26) of the charging stand 30 so that the metal piece 30 slides down. Limited to low power chargers.

[0005]

In the above non-contact type charging device, as shown in FIG. 6, metal pieces such as paper clips, coins, etc., are removed when no electric device is placed on the charging stand. When placed on the receiving part of the charging stand, there was a problem that the metal piece abnormally generated heat due to electromagnetic induction heating, touching it and causing burns, and the resin case housing constituting the charging stand was thermally melted. . Further, the circuit board forming the circuit for charging the rechargeable battery of the electric device and the other electric circuit are installed away from the secondary coil in order to avoid heat generation due to the electromagnetic induction effect. Therefore, miniaturization may be impaired.

In view of the above problems, the present invention prevents an abnormal heat generation due to electromagnetic induction heating due to intervening metal pieces in an apparatus for charging a rechargeable battery of an electric device without contact by electromagnetic induction. An object of the present invention is to provide a contactless charging device that can improve safety, reduce the loss of an internal circuit, have a simple structure, and can be downsized.

[0007]

DISCLOSURE OF THE INVENTION The present invention provides an electric device including a rechargeable battery, a secondary coil for supplying electric power to the rechargeable battery, a rectifier, etc., and a primary coil connected to an AC power source. A charging stand having a supporting portion for supporting the device, and a secondary coil and a coil when the electric device is engaged with the charging stand.
In a non-contact type charging device used for electric equipment in which the following coil charges the rechargeable battery by electromagnetic induction, the support part of the charging stand is provided so as to surround the body part of the electric device and is wound around the support part. A primary coil and a secondary coil wound around the body centering around the longitudinal direction of the electric device.
A circuit board, which is arranged such that the winding width surface of the secondary coil and the winding width surface of the secondary coil face each other, and which forms another electric circuit including a rectifier of an electric device, is provided with a winding axis substantially at the center of the secondary coil. The feature is that they are provided in parallel.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION A non-contact type charging device of the present invention is connected to an AC power source, and a rechargeable battery, an electric device incorporating a secondary coil for supplying electric power to the rechargeable battery, a rectifier and the like.
A charging stand having a supporting part for supporting the electric equipment, which has a built-in secondary coil, and is 2 when the electric equipment is engaged with the charging stand.
The secondary coil and the primary coil charge the rechargeable battery by electromagnetic induction. The support of the charging stand is provided so as to surround the body of the electric device, and the primary coil is wound around the support. The secondary coil is wound around the body around the longitudinal direction of the electric device. A circuit board that is arranged so that the inner circumferential surface of the winding of the primary coil and the outer circumferential surface of the winding of the secondary coil face each other and that forms another electric circuit including a rectifier of an electric device is located substantially at the center of the secondary coil. It is installed parallel to the winding axis.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the contactless charging device according to the present invention will be described below with reference to FIGS.

FIG. 1 is a perspective view showing an embodiment of a non-contact type charging device according to the present invention. FIG. 2 is a partial cross-sectional view of the primary coil section and the secondary coil section of the contactless battery charger of FIG. As shown in FIGS. 1 and 2, an electric device 1 which is a portion to be charged is a secondary coil that uses an air-core coil in which a previously insulated copper wire is wound and the wound coil is fixed with an insulating material. Two
And a circuit board 3 forming another electric circuit (not shown) including a rectifier. The charging stand 5 includes a support portion 6 that supports the outer periphery of the body of the electric device 1, a primary coil 7 that is provided inside the support portion, and a receiving portion 8 that receives the bottom surface portion of the electric device. .

The charging stand 5 is provided with a support portion 6 for supporting the outer periphery of the body of the electric device 1 and a recessed receiving portion 8 for receiving the bottom surface of the electric device 1, and is wound around the inner peripheral portion 6a of the support portion 6. A primary coil 7 having a wire is provided. The electric device 1 is provided with a circuit board 3 forming another electric circuit including a rectifier, and the secondary coil 2 is fixed to the inside 1a of the body of the electric device 1 with an adhesive or the like. The secondary coil 2 provided in the electric device 1 and the primary coil 7 provided in the support part 6 of the charging stand 5 are located at positions where the winding width surfaces face each other, and are higher than the receiving part 8 of the charging stand 5, and the electric device It is provided at a position higher than the bottom surface of 1. The circuit board 3 of the electric device 1 is provided substantially in the center of the secondary coil 2 in parallel with the winding axis.

FIG. 3 is a diagram schematically showing the positional relationship between the primary coil and the secondary coil and the distribution of magnetic flux. From the figure, 1
The secondary coil 7 and the secondary coil 2 are air core coils having an air core inside the winding. In this case, the magnetic flux φ created by the primary coil 7
Since 1 is weakened outward with respect to the center of the cross section of the winding of the primary coil 7, the secondary coil 2 is assumed to have almost the same winding width as the primary coil 7 and the secondary coil 2 Coil 2
It is desirable to bring the winding width surfaces facing each other closer. And
It is desirable that the circuit board 3 of the electric device 1 be provided substantially in the center of the secondary coil and parallel to the winding axis with the longitudinal direction as an axis.

With this arrangement, the circuit board 3 avoids heat generation due to electromagnetic induction without interlinking because the wiring pattern of the circuit board is in the same direction as the magnetic flux of the primary coil. Therefore, it can be stored in the electric device 1 in a lump. Further, the metal pieces such as coins slide down without remaining on the support portion 6 of the charging stand 5, so that a safe contactless charging device in which heat generation or the like due to electromagnetic induction does not occur can be made.

Next, a modified embodiment of the present invention is shown in FIG. FIG. 4 is a perspective view of a contactless charging device for an electric device in which the electric device is mounted horizontally. As shown in the figure, the electric device 11 that is the part to be charged has a secondary coil that is an air-core coil in which a pre-insulated copper wire is wound around a part of the body and the wound coil is fixed with an insulating material. 12 and a circuit board 13 forming another electric circuit including a rectifier. Charging stand 15
Is provided with a support portion 16 that surrounds the body of the electric device 11, a primary coil 17 that is provided inside the inner periphery of the support portion, a receiving portion 18 that receives the bottom surface portion of the electric device, and a stopper 19 that receives one end portion. is there.

The charging stand 15 is provided with a support portion 16 that surrounds the body of the electric device 11, a sloping recessed receiving portion 18 that receives the bottom surface of the electric device 11, and a stopper 19 that receives one end of the electric device 11. A primary coil 17 having a winding on the inner circumference is provided. The electric device 11 is provided with a circuit board 13 forming another electric circuit including a rectifier, and the secondary coil 12 is fixed to a part of the body of the electric device 11 with an adhesive or the like. The secondary coil 12 of the electric device 11 and the primary coil 17 provided on the support portion 16 of the charging stand 15 are positioned such that the winding width surfaces thereof face each other, and are closer to the center than the stopper 19 of the charging stand 15,
Moreover, it is arranged near the center of the electric device 11.
The circuit board 13 of the electric device 11 has the secondary coil 12
It is installed approximately parallel to the winding axis.

With such an arrangement, the circuit board 13 does not interlink with the magnetic path because the wiring pattern of the circuit board is in the same direction as the magnetic flux of the primary coil, and the circuit board 13 does not generate heat due to electromagnetic induction. Electrical equipment that can be avoided 1
Can be stored together inside. Since the metal pieces such as coins also have the same direction as the magnetic flux of the primary coil, it is possible to provide a safe non-contact type charging device in which heat generation due to electromagnetic induction heating does not occur. The contactless charging device of the present invention has been described above, but the present invention is not limited to these embodiments. For example, in the embodiment of the present invention, the primary coil is wound around the support portion of the charging stand, but an air-core coil in which a pre-insulated copper wire is wound and the wound coil is fixed with an insulating material is used. May be.

[0017]

As is apparent from the above, the non-contact type charging device of the present invention has a primary coil wound around a supporting portion surrounding a body of an electric device and a longitudinal direction of the electric device as an axis. It is composed of a secondary coil wound around the body, and is arranged so that the winding width surface of the primary coil and the winding width surface of the secondary coil face each other.
A circuit board that forms another electric circuit including a rectifier of electric equipment is provided substantially in the center of the secondary coil in parallel with the winding axis.
As a result, since the wiring pattern of the circuit board of the electric device is in the same direction as the magnetic flux of the primary coil, heat generation due to electromagnetic induction can be avoided without the magnetic flux interlinking and loss of the internal circuit. It is possible to reduce the number of the electric appliances and store them inside the electric device. Then, a metal piece such as a coin slides down without remaining on the support portion of the charging stand, and a safe non-contact type charging device in which heat generation due to electromagnetic induction heating does not occur can be realized. Furthermore, since the electric device is not provided with a special circuit or the like, it is possible to provide a non-contact type charging device for the electric device which is suitable for downsizing and weight reduction.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a non-contact type charging device of the present invention.

FIG. 2 is a partial cross-sectional view of the embodiment shown in FIG.

3 is a schematic diagram of magnetic flux distribution in the partial cross-sectional view of FIG.

FIG. 4 is a perspective view of another modified embodiment of the contactless charging device of the present invention.

FIG. 5 is a partial cross-sectional view of a conventional non-contact type charging device.

FIG. 6 is a schematic diagram of magnetic flux distribution on the charging stand and the metal piece of FIG.

FIG. 7 is a cross-sectional view in which a charging stand of a conventional non-contact type charging device is inclined.

[Explanation of symbols]

1 electrical equipment 2 Secondary coil 3 circuit board 5 charging stand 6 Support 7 Primary coil

Claims (2)

[Claims] 1. A rechargeable battery and a power supply 2 for supplying power to the rechargeable battery.
An electric device including a secondary coil, a rectifier, and the like, and a charging stand that includes a primary coil that is connected to an AC power supply and that has a supporting portion that supports the electric device, and engages the electric device with the charging stand. In a non-contact type charging device used in an electric device in which a secondary coil and a primary coil are charged by an electromagnetic induction action when the charging is performed, the supporting part is provided so as to surround a body part of the electric device. And a secondary coil wound around the body with the longitudinal direction of the electric device as an axis. A winding width surface of the primary coil and a winding of the secondary coil A contactless charging characterized in that a circuit board, which is arranged so as to face the width surface and forms another electric circuit including a rectifier of the electric device, is provided substantially in the center of the secondary coil in parallel with the winding axis. apparatus. 2. An air-core coil in which an insulated copper wire is wound around the primary coil and the secondary coil, and the wound coil is fixed with an insulating material.
The contactless charging device described.