JPH08181026A - Noncontact power transmitter - Google Patents

Abstract

PURPOSE: To efficiently transmit large power irrespective of the shape of a load equipment. CONSTITUTION: In a transmitter for transmitting power contactless from the primary coil of a power source 3 side to the secondary coil of a load equipment 4 side, the power source 3 has a fitting hole 30 in which the equipment 4 is inserted, and a C-shaped core 10 in which the primary coil is wound and the hole 30 is disposed between both side pieces. The equipment 4 has an I-shaped core 21 in which the secondary coil is wound and both the end faces are opposed to the opposed surfaces of both the side pieces of the core 10 at the time of mounting in the hole 30. Many magnetic fluxes flow from the side piece end of the C-shaped core of the primary side to the I-shaped core of the secondary side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact power transmission device for non-contactly transmitting power by electromagnetic induction between a primary coil on a power supply unit side and a secondary coil on a load device side.

[0002]

2. Description of the Related Art As shown in FIG. 7, a primary coil 1 which is an air-core coil for transmitting electric power in a contactless manner.
There is one that transmits electric power between the secondary coil 2 and the secondary coil 2 by electromagnetic induction. FIG. 8 is a block circuit diagram of the above-mentioned one, in which 3 is a power supply device, 4 is a load device, 5 is a rectifying / smoothing circuit, 6 is an oscillating circuit, 7 is a secondary side rectifying circuit, and 8 is a load. Since power can be transmitted between the power supply device 3 and the load device 4 without exposing the charging part, the power supply device 3 and the load device 4 are often used for those requiring waterproofing.

By the way, the transformer section constituted by the air-core coil has no problem in transmitting a small amount of electric power, but in order to transmit a large amount of electric power, the primary and secondary coupling of the transformer is poor, and the electric power transmission amount is limited. There is. For this reason, when it is desired to transmit household power, the primary coil 1 and the secondary coil are wound around the C-shaped cores 10 and 20, respectively, as disclosed in Japanese Patent Laid-Open No. 2-296308. As shown in FIG. 9, the end surfaces of both side pieces of both cores 10 and 20 are made to face each other.

[0004]

However, with the above structure, when the load device is formed in a fine shape such as an electric toothbrush, when the core 20 is placed at the bottom of the device, the core 1
There is no choice but to reduce the distance B between both side pieces of 0 and 20. At this time, the distance B may be smaller than the distance A between the core 10 and the core 20, and in such a dimensional relationship, The magnetic flux emitted from the core 10 on the primary side does not flow to the core 20 on the secondary side through the interval A, and the magnetic flux tends to rotate only on the primary side through the interval B which is the lower magnetic resistance side. As a result, the coupling becomes poor and it becomes impossible to transfer a large amount of power.

The present invention has been made in view of the above points, and an object thereof is non-contact power transmission capable of efficiently transmitting a large amount of power without being influenced by the shape of a load device. To provide the equipment.

[0006]

SUMMARY OF THE INVENTION According to the present invention, however, in a transmission device for transmitting electric power in a contactless manner between a primary coil on the power supply unit side and a secondary coil on the load device side, The load device includes a mounting hole to be inserted and a C-shaped core around which the primary coil is wound and the mounting hole is located between both side pieces. It is characterized in that both end surfaces are provided with I-shaped cores that face the facing surfaces of both side pieces of the C-shaped core when mounted in the mounting holes.

At this time, it is preferable that the mounting hole of the power supply device and the load device have a defining means for defining the mounting direction. When the housing of the load device is cylindrical, the I-shaped core of the housing is provided. It is preferable that the portion where the end surface is located is a flat surface. Further, it is preferable that the mounting hole of the power supply device is formed so as to have a bottom surface at a position deeper than a through hole or a portion where both side pieces of the C-shaped core are positioned.

[0008]

According to the present invention, most of the magnetic flux from the tip of the side piece of the C side core on the primary side flows to the I type core on the secondary side, and a large amount of magnetic flux flows to the core on the secondary side. be able to.
It should be noted that the mounting hole in the power supply device may be any as long as it can position the load device when the load device is inserted,
It does not matter its shape.

If the mounting hole of the power supply device and the load device are provided with the regulating means for regulating the mounting direction, the positional relationship between the C-shaped core and the I-shaped core can be always kept correct.
When the housing of the load device has a cylindrical shape, if the portion of the housing where the end surface of the I-shaped core is located is made flat, the gap between the C-shaped core and the I-shaped core can be reduced, Further, if the mounting hole of the power supply device is formed so as to have a bottom surface at a position deeper than the through hole or the portion where both side pieces of the C-shaped core are located, when a metal such as a coin is placed in the mounting hole. It is possible to avoid the heat generation problem.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the illustrated embodiments. In the present invention, as shown in FIG. 1, the primary coil 1 on the power supply unit side is wound around a C-shaped core 10 and the load device side is mounted. When the secondary coil 2 is wound around the I-shaped core 21 and power is transmitted from the power supply side to the load side, the I-shaped core 21 is located between both sides of the C-shaped core 10 and Both end surfaces of 21 are opposed to the inner surfaces of both side pieces of the C-shaped core 10. When considering the C-type core 10 alone, the magnetic flux from the primary coil 1 passes between the tips of both side pieces as shown in FIG. 2A, but the I-type core 21 is inserted in this magnetic path. For this reason, most of the magnetic flux is the I-shaped core 21.
Since it passes through, the coupling is good and a large amount of power can be transmitted.

In order to achieve the above-mentioned coupling, specifically, as shown in FIG. 3, a mounting hole 30 into which the load device 4 can be inserted is provided on the side of the power supply device 3, and the C-shaped core 10 is provided.
Is arranged in the power supply device 3 so that the mounting hole 30 is located between the both side pieces. Further, in the load device 4, the I-shaped core 21 is arranged in the load device 4 so that both end surfaces thereof are located on the side surfaces of the load device 4. When the load device 4 is inserted into the mounting hole 30, the C-shaped core 10 of the power supply device 3 and the I-shaped core 21 of the load device 4 are kept in the above positional relationship.

However, the housing 40 of the load device 4 has a cylindrical shape, not a rectangular cross section, and has a corresponding mounting hole 3
If 0 is also circular in cross section, the position around the axis of the load device 4 becomes indefinite, and in this case, as shown in the figure, the mounting hole 30 and the housing 4 of the load device 4 are
0 and the concave and convex portions 31 and 42 for restricting the position in the axial direction by mutual engagement are provided. As shown in FIG. 4, if two sets of the concave-convex portions 31 and 42 are provided at symmetrical positions, the load device 4 has the cores 10 and 2 at two positions in the axial direction.
It is possible to insert it into the mounting hole 30 while maintaining the positional relationship of 1.

When the housing 40 of the load device 4 has a cylindrical shape, as shown in FIG.
Of the I-shaped core 21 on the flat surface 4
3, and in accordance with this, the C-shaped core 10 in the mounting hole 30
The flat surface 33 may be formed on the outer peripheral side of the side piece. The presence of such flat surfaces 43 and 33 causes the core 10,
In addition to reducing the gap G between the cores 21 to further improve the coupling, the core 21 is positioned so as to be located between both side pieces of the core 10.

By the way, if a current is passed through the primary coil 1 with a metal such as a coin placed in the mounting hole 30 of the power supply device 3, an eddy current is generated in the metal and the metal heats up. Invite. In the embodiment shown in FIG. 6, in order to prevent such a situation from occurring, the C-shaped core 10 is laterally arranged as the through hole that reaches the mounting hole 30 of the power supply device 3 to the lower surface of the power supply device 3. Even if metal is put in the mounting hole 30, the metal is allowed to fall downward. When the load device 4 is used around water, the load device 4
There is no possibility that water dripping from the water will accumulate in the mounting hole 30 and cause dirt.

The mounting hole 30 may be deep enough so that even if metal is put into the mounting hole 30, it does not stay at the position where it interlinks with the magnetic flux. Alternatively, the load device 4 may be inserted into the mounting hole 30 from the lower side as an opening downward. In this case, a structure for preventing the load device 4 from coming off is required, but the metal does not remain in the mounting hole 30.

[0016]

As described above, in the present invention, most of the magnetic flux from the tip of the side piece of the C-shaped core on the primary side is I on the secondary side.
It flows through the mold core, and because the gap between both cores can be kept small even if the load equipment is thin,
The coupling between the primary side and the secondary side can be maintained in a good state, and high power can be transmitted.

If the mounting hole of the power supply device and the load device are provided with a regulating means for regulating the mounting direction, the positional relationship between the C-shaped core and the I-shaped core can always be maintained correctly, and the coupling failure can be prevented. Will not occur. When the housing of the load device has a cylindrical shape, if a portion of the housing where the end surface of the I-shaped core is located is made flat, the gap between the C-shaped core and the I-shaped core is reduced to further improve the coupling. In addition to being improved, the flat surface can also serve as the defining means.

Further, if the mounting hole of the power supply device is formed to have a bottom surface at a position deeper than the through hole or the portion where both side pieces of the C-shaped core are located, a metal such as a coin is placed in the mounting hole. It is possible to avoid the problem of heat generation when being struck.

[Brief description of drawings]

FIG. 1 shows an arrangement of a C-shaped core and an I-shaped core in the present invention, (a) is a perspective view and (b) is a front view.

2A and 2B show the flow of magnetic flux in the above, wherein FIG. 2A is an explanatory view of a C-type core alone, and FIG. 2B is an explanatory view of a combination of a C-type core and an I-type core.

FIG. 3 is a perspective view of one embodiment.

FIG. 4 shows another embodiment, (a) is a plan view of a power supply device, and (b) is a bottom view of a load device.

FIG. 5 shows another embodiment, (a) is a horizontal sectional view,
(b) is an enlarged sectional view.

FIG. 6 is a perspective view of a power supply device according to still another embodiment.

FIG. 7 is a perspective view of a conventional example.

FIG. 8 is a block circuit diagram of the above.

FIG. 9 is an explanatory diagram of another conventional example.

[Explanation of symbols]

 1 Primary coil 2 Secondary coil 3 Power supply device 4 Load device 10 C-type core 21 I-type core 30 Mounting hole

Claims (4)

[Claims] 1. A transmission device for transmitting electric power in a contactless manner between a primary coil on the power supply device side and a secondary coil on the load device side, wherein the power supply device has a mounting hole into which the load device is inserted,
A C-shaped core in which the primary coil is wound and the mounting hole is located between both side pieces, and the load device has the secondary coil wound and is mounted in the mounting hole. A non-contact power transmission device, characterized in that both end faces are provided with I-shaped cores facing the facing faces of both side pieces of the C-shaped core, respectively. 2. The non-contact power transmission device according to claim 1, wherein the mounting hole of the power supply device and the load device are provided with defining means for defining a mounting direction. 3. The non-contact power transmission device according to claim 1, wherein the load device has a flat surface in a portion of the cylindrical housing where the end surface of the I-shaped core is located. 4. The mounting hole of the power supply device is formed to have a bottom surface at a position deeper than a through hole or a portion where both side pieces of the C-shaped core are located.
The contactless power transmission device described.