JP7122137B2 - Electric unit for wireless power supply - Google Patents

Description

The present invention relates to an electric unit for wireless power supply installed on a partition such as a wall of a building.

A wireless power supply system installed on a partition wall such as a wall of a building is known (see, for example, Patent Document 1). This wireless power supply system includes a power transmission unit installed on the indoor side of the partition to supply power, and a power reception unit installed on the outdoor side of the partition and wirelessly receiving power from the power transmission unit.

If the magnetic field generated by the power transmission unit is emitted to the outside as it is, it will adversely affect the surrounding electronic devices or interact with the surrounding electronic devices to reduce power supply efficiency. Therefore, the wireless power supply system usually includes a shield member for preventing the magnetic field generated by the power transmission unit from leaking to the outside. As an example of this, in Patent Document 1, a plate-like shield member is arranged on the side opposite to the partition with a core material for power reception interposed therebetween.

JP 2015-185719 A

In such a wireless power supply system, a large-sized shield member is required in order to prevent leakage of the magnetic field to the outside over a wide range. After studying the technology disclosed in Patent Document 1, the inventors of the present invention have found that the effect of preventing leakage of the magnetic field from the shield member to the outside (hereinafter referred to as "magnetic field leakage prevention effect") is ensured, and the size of the shield member is reduced. It was recognized that there was room for improvement.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems, and an object thereof is to provide a wireless power supply system capable of reducing the size of a shield member while ensuring the effect of preventing magnetic field leakage.

An electric unit according to one aspect of the present invention for solving the above problems is an electric unit that constitutes either a power receiving unit or a power transmitting unit used in a wireless power supply device, and is arranged between the power receiving unit and the power transmitting unit. An elongated core material arranged on one side in the wall thickness direction of the partition body and around which the coil is wound, and a shield member, wherein the shield member is separated from the partition body with the core material interposed therebetween. It has a first shield part arranged on the opposite side and a second shield part covering the end of the core material from one side in the longitudinal direction of the core material.

When the shield member also has the second shield portion, the length in the longitudinal direction of the shield member can be shortened while configuring the same magnetic field reduction range as compared with the case where the shield member has only the first shield portion. Therefore, it is possible to reduce the size of the shield member while ensuring the effect of preventing leakage of the magnetic field of the shield member.

ADVANTAGE OF THE INVENTION According to this invention, a shield member can be reduced in size, ensuring the magnetic field leakage prevention effect.

It is a figure explaining the principle of a wireless electric power feeding system. It is a figure explaining the principle of a wireless electric power feeding system. 1 is a cross-sectional view showing a schematic configuration of a wireless power supply system according to a first embodiment; FIG. 4 is a schematic diagram showing a magnetic field reduction range of the wireless power supply system of FIG. 3; FIG. FIG. 10 is a cross-sectional view showing a schematic configuration of a wireless power supply system according to a second embodiment; FIG. 11 is a cross-sectional view showing a schematic configuration of a wireless power supply system according to a third embodiment; FIG. 11 is a cross-sectional view showing a schematic configuration of a wireless power supply system according to a modification; FIG. 11 is a cross-sectional view showing a schematic configuration of a wireless power supply system according to a modification;

Hereinafter, in the embodiments and modified examples, the same constituent elements are denoted by the same reference numerals, and overlapping descriptions are omitted. Moreover, in each drawing, for convenience of explanation, some of the constituent elements are appropriately omitted, and the dimensions of the constituent elements are shown by appropriately enlarging or reducing them.

Before specifically describing the embodiments of the present invention, basic matters will be described.
FIG. 1 is a diagram for explaining the principle of a wireless power supply system. The wireless power supply system 1000 includes a power transmission unit 100 installed on one side of the partition body 40 in the wall thickness direction D with respect to the partition body 40, and a power reception unit 100 installed on the other side of the partition body 40 in the wall thickness direction D. and a unit 200 . The power transmitting unit 100 is for supplying power, and the power receiving unit 200 is for wirelessly receiving power from the power transmitting unit 100 . The power transmission unit 100 is connected to an AC power supply (not shown), and the power reception unit 200 is connected to an electrical device (not shown) such as a motor. Throughout this specification, the power transmission unit and the power reception unit may be collectively referred to as an electrical unit.

The power transmission unit 100 includes an elongated first core member 10 and a first coil 12 . The first coil 12 is a solenoid coil wound around the first core 10 . The power receiving unit 200 includes an elongated second core member 20 and a second coil 22 . The second coil 22 is also a solenoid coil wound around the second core 20 . The first core material 10 and the second core material 20 are made of a magnetic material such as iron, and increase the magnetic flux passing through these core materials. The first core member 10 and the second core member 20 are arranged parallel to each other in the longitudinal direction. In addition, the first core member 10 and the second core member 20 are arranged at overlapping positions when viewed from the wall thickness direction D. As shown in FIG.

A current flowing through the first coil 12 generates a magnetic field inside and around the first core 10 . Part of the magnetic flux generated by this magnetic field is emitted from one end in the longitudinal direction of the first core material 10 and reaches one end in the longitudinal direction of the second core material 20 . is released from the other longitudinal end of the first core material 10 and tries to propagate through the surrounding space so as to follow the second path B2 reaching the other longitudinal end of the first core material 10 . Such magnetic flux links the second coil 22 . Electromotive force is generated in the second coil 22 by electromagnetic induction due to temporal fluctuation of this magnetic flux. Thus, power is wirelessly supplied from the power transmission unit 100 to the power reception unit 200 .

On the other hand, around the first coil 12 , there is also a magnetic flux BL that circulates at a location away from the power receiving unit 200 without interlinking with the second coil 22 . The magnetic field that forms the magnetic flux BL has an adverse effect on surrounding electronic devices, or interacts with surrounding electronic devices to cause a reduction in power supply efficiency.

FIG. 2 is also a diagram for explaining the principle of the wireless power supply system. Wireless power supply system 1100 includes a partially improved power receiving unit 210 instead of power receiving unit 200 in FIG. Other configurations of wireless power supply system 1100 are the same as those of wireless power supply system 1000 in FIG.

Power receiving unit 210 includes, in addition to the structure of power receiving unit 200 in FIG. 1 , flat shield member 30 arranged on the opposite side of partition 40 with second core member 20 interposed therebetween. The shield member 30 is configured using a conductive material such as aluminum or copper, or a material with relatively high magnetic permeability such as iron or ferrite. Other configurations of power receiving unit 210 are the same as those of power receiving unit 200 .

Of the magnetic flux emitted from one end in the longitudinal direction of the first core member 10, the magnetic flux that reaches the shield member 30 passes through a magnetic circuit with relatively low magnetic resistance formed by the shield member 30 and circulates around the first core member. Return to the other end of 10. Such magnetic flux does not circulate behind the shield member 30 when viewed from the first core member 10 . This creates a range in which magnetic field leakage is reduced.

The range in which the leakage of the magnetic field is effectively reduced by the shield member 30 (hereinafter referred to as the magnetic field reduction range) includes both ends in the longitudinal direction X of the first core member 10 and the longitudinal direction Y of the shield member 30. It is determined according to the positional relationship with both ends. Specifically, on a cut plane along the longitudinal direction X of the first core member 10 , one end of the first core member 10 in the longitudinal direction X and one end of the shield member 30 in the longitudinal direction Y are imaginary. Let La be the line. An imaginary line passing through the other end in the longitudinal direction X of the first core member 10 and the other end in the longitudinal direction X of the shield member 30 is Lb. A range surrounded by the virtual lines La and Lb and the shield member 30 and formed outside the shield member 30 is a magnetic field reduction range. FIG. 2 shows a portion 60 of the magnetic field reduction range.

For example, this wireless power supply system is applied to a power supply system for a motor that drives an electric shutter retrofitted at the time of renovation. In this case, the power receiving unit 210 is installed between the shutter box and the partition. Since the shutter box incorporates a motor and an electronic circuit, it is necessary to prevent the magnetic field from leaking into the shutter box. Here, Lu is the length in the longitudinal direction of the first core member 10, Lt is the transmission distance that is the distance in the wall thickness direction D between the first core member 10 and the second core member 20, and Lt is the length of the shield member 30. Let d be the length in the longitudinal direction. As a typical example, in the case of a wireless power supply system with Lu = 20 cm and Lt = 15 cm, experiments have shown that d must be 50 cm or more in order to prevent leakage of the magnetic field within the necessary range in the shutter box. found out by However, when trying to install a shield member of such a size between the shutter box and the partition, it is likely to interfere with existing building members, making installation difficult.

The present inventors discovered that by devising the shape of the shield member, it is possible to reduce the size of the shield member in the longitudinal direction while preventing leakage of the magnetic field to the outside.

[First Embodiment]
FIG. 3 is a cross-sectional view showing a schematic configuration of a wireless power supply system 1200 including a power receiving unit 220 according to one embodiment. Wireless power supply system 1200 includes an improved power receiving unit 220 in place of power receiving unit 210 of FIG. Other configurations of wireless power supply system 1200 are the same as those of wireless power supply system 1100 in FIG.

The power receiving unit 220 includes a shield member 32 that covers the second core member 20 and the second coil 22 instead of the shield member 30 in FIG. The shield member 32 includes a first shield portion 32a arranged on the opposite side of the partition body 40 with the partition body 40 interposed therebetween, and an end portion of the second core member 20 on one side of the second core member 20 in the longitudinal direction. and a plurality of second shield portions 32b covering from the inside. The first shield part 32a has a flat plate shape extending in a direction orthogonal to the wall thickness direction D of the partition body 40 . The first shield part 32a covers the entire second coil 22 wound around the second core material 20 and the second core material 20 from one side in the wall thickness direction D. As shown in FIG. The second shield part 32b is connected to both sides of the first shield part 32a in the longitudinal direction Y via a bent part 32e, and extends from the bent part 32e so as to approach the partition body 40. As shown in FIG. The second shield part 32b is provided perpendicular to the first shield part 32a. The second shield part 32b has a flat plate shape, and an end portion thereof on the side of the partition body 40 is in contact with the partition body 40. As shown in FIG. Other configurations of power receiving unit 220 are common to the configuration of power receiving unit 210 in FIG.

In the wireless power supply system 1200 , the shield member 32 forms the magnetic field reduction range 62 behind the shield member 32 when viewed from the first core member 10 as in the wireless power supply system 1100 of FIG. 2 . The magnetic field reduction range 62 is determined according to the positional relationship between both ends in the longitudinal direction X of the first core member 10 and both ends in the longitudinal direction Y of the shield member 32 . More specifically, a cut plane along the longitudinal direction X of the first core member 10 passes through one end of the first core member 10 in the longitudinal direction X and one end of the shield member 32 in the longitudinal direction Y. Let the virtual line be Lc. An imaginary line passing through the other end in the longitudinal direction X of the first core member 10 and the other end in the longitudinal direction Y of the shield member 32 is Ld. "One end of the shield member 32 in the longitudinal direction Y" in this embodiment is the end of the second shield part 32b on the partition body 40 side. In addition, "the other end of the shield member 32 in the longitudinal direction Y" is the end of the second shield part 32b on the partition body 40 side. A range surrounded by the virtual lines Lc and Ld and the shield member 32 and formed outside the shield member 32 is the magnetic field reduction range 62 .

FIG. 4 is a schematic diagram showing the magnetic field reduction range 62 by the wireless power supply system 1200 of FIG. Illustration of the partition is omitted. Let θ be the angle formed by the virtual lines Lc and Ld with the wall thickness direction D, respectively. In FIG. 4, a shield member 32 having a length of a for the first shield portion 32a and a length of b for the second shield portion 32b is used to generate a magnetic field within an angle from 0 to θrad with respect to the wall thickness direction D. It has been shown that a reduction range can be created. Further, according to FIG. 4, in order to form the same magnetic field reduction range as described above using the flat shield member 30, the shield member 30 having a length d=a+2·c in the longitudinal direction Y is required. I understand. However, c=b·tan θ. In other words, the wireless power supply system 1200 can form the same magnetic field reduction range with a shield member that is 2·c shorter in the longitudinal direction Y than the wireless power supply system 1100 of FIG. 2 .

As in the above example, in a wireless power supply system with Lu = 20 cm and Lt = 15 cm, when the shield member 32 is applied with θ = π/4, the length of the shield member 32 in the longitudinal direction Y (the length of the first shield part 32a is The length a in the longitudinal direction Y is 35 cm. It has been experimentally confirmed that a shield member of such a size makes it difficult for interference with existing building members to occur, so that it can be easily installed between the aforementioned shutter box and the partition body. rice field.

As described above, when the shield member 32 also has the second shield portion 32b, compared to the case where the shield member 32 only has the first shield portion 32a, the same magnetic field reduction range is configured while the longitudinal direction of the shield member 32 is reduced. The length in direction Y can be shortened. Therefore, the size of the shield member can be reduced while ensuring the effect of preventing leakage of the magnetic field of the shield member 32 .

[Second embodiment]
The second shield part may have a connection part to which a fixing member used for fixing the shield member to the partition is connected. FIG. 5 is a cross-sectional view showing a schematic configuration of the power receiving unit 240 according to this embodiment. Power receiving unit 240 includes a further improved shield member 34 instead of shield member 32 in FIG. Other configurations of power receiving unit 240 are common to the configuration of power receiving unit 220 in FIG.

The shield member 34 has a first shield portion 34a and a second shield portion 34b, like the shield member 32 of FIG. The second shield portion 34b includes a connecting portion 70a.

The second shield part 34b is fixed to the partition body 40 using a fixing member 80a. As an example, the fixing member 80a is a screw member, and the connecting portion 70a is a female screw hole into which the screw member is screwed. The fixing member 80a is screwed into the connection portion 70a so as to pass through the partition 40 from the side opposite to the shield member 34 with the partition 40 interposed therebetween.

According to this embodiment, since the second shield part 34b has the connection part 70a to which the fixing member 80a used for fixing the shield member to the partition body 40 is connected, the number of parts used for fixing the shield member 34 can be reduced. can be reduced. Thereby, the shield member 34 can be easily fixed to the partition body 40 .

[Third Embodiment]
The shield member has a third shield part extending in the in-plane direction of the partition from the end of the second shield on the partition body side, and the third shield part is used for fixing the shield member to the partition. good. FIG. 6 is a cross-sectional view showing a schematic configuration of the power receiving unit 260 according to this embodiment. The power receiving unit 260 includes a further improved shield member 36 instead of the shield member 32 of FIG. Other configurations of power receiving unit 260 are common to the configuration of power receiving unit 220 in FIG.

The shield member 36 has a third shield portion 36c in addition to the first shield portion 36a and the second shield portion 36b similar to the shield member 32 of FIG. The third shield part 36 c extends from the end of the second shield part 36 b on the side of the partition body 40 to the outside of the shield member 36 in the in-plane direction of the partition body 40 .

For example, the third shield part 36c is fixed to the partition body 40 using the fixing member 80b. As an example, the fixing member 80b is a screw member. The fixing member 80b penetrates the third shield part 36c from the opposite side of the partition 40 and is screwed into the partition 40 .

Alternatively, the third shield part 36c may be fixed to the partition body 40 using an adhesive or the like.

Alternatively, the third shield portion 36c may extend inside the shield member 36 from the end of the second shield portion 36b.

According to this embodiment, the shield member 36 has a third shield portion 36c for use in fixing to the partition body 40. As shown in FIG. Therefore, the shield member 36 can be easily fixed to the partition body 40 by various methods.

In the embodiment described above, for example, the embodiment of FIG. 3, the power receiving unit 220 includes the shield member 32 on the side opposite to the partition body 40 with the second core member 20 interposed therebetween. Alternatively or additionally, the power transmission unit 100 may include a shield member having the same structure on the side opposite to the partition body 40 with the first core member 10 interposed therebetween. According to this embodiment, the magnetic field reduction region is formed on the side opposite to the partition body 40 when viewed from the power transmission unit 100 . This effectively reduces the magnetic field leakage in this region.

Although the present invention has been described above based on the embodiments, the embodiments merely show the principles and applications of the present invention. In addition, many modifications and changes in arrangement are possible in the embodiments without departing from the spirit of the present invention defined in the claims.

[First modification]
FIG. 7 is a cross-sectional view showing a schematic configuration of power receiving unit 280 according to this modification. The power receiving unit 280 includes a shield member 38 to which a connecting portion is added, instead of the shield member 34 of FIG. Other configurations of power receiving unit 280 are common to the configuration of power receiving unit 240 in FIG.

The shield member 38 has a first shield portion 38a and a second shield portion 38b, like the shield member 34 of FIG. The second shield portion 38b has a second connection portion 70b in addition to the connection portion 70a.

The second shield portion 38b is fixed to the partition body 40 using fixing members 80a and 90. As shown in FIG. A fixing member 90 connected to the second connecting portion 70 b has a mounting fixture 92 fixed to the partition body 40 and a screw member 94 inserted through the mounting fixture 92 . The fixture 92 is, for example, an L-shaped angle member. The second connection portion 70b has a hole 72b through which the screw member 94 is inserted, and a nut 72c attached to the inner surface of the second shield portion 38b by adhesion or the like. The fixture 92 is screwed into the nut 72c so as to pass through the fixture 92 from the side opposite to the second shield portion 38b with the fixture 92 interposed therebetween.

According to this modification, the second shield part 38b has the second connection part 70b in addition to the connection part 70a. The second shield part 38 b can be fixed to the partition body 40 .

[Second modification]

FIG. 8 is a cross-sectional view showing a schematic configuration of a power receiving unit 290 according to this modification. The power receiving unit 290 includes a shield member 39 having a different shape from the shield member 32 in FIG. Other configurations of power receiving unit 290 are common to the configuration of power receiving unit 220 in FIG.

The shield member 39 covers the second core member 20 from the side opposite to the partition body 40 with the second core member 20 interposed therebetween, and extends the end portion of the second core member 20 in the longitudinal direction Z of the second core member 20 . cover from at least one side of the As an example in FIG. 8 , the shield member 39 has an arcuate cross-sectional shape on a cut surface along the longitudinal direction Z of the second core member 20 . The length of the shield member 39 in the longitudinal direction Y is a', and the length in the wall thickness direction D is b'. As in FIG. 4 , an imaginary line passing through one end of the first core member 10 in the longitudinal direction X and one end of the shield member 39 on the cut surface along the longitudinal direction X of the first core member 10 . is Le, and an imaginary line passing through the other end of the first core member 10 in the longitudinal direction X and the other end of the shield member 39 is Lf. A range formed outside the shield member 39 is a magnetic field reduction range 64 . Let θ′ be the angle formed by the virtual lines Le and Lf with the wall thickness direction D, respectively. It can be seen that in order to form the same magnetic field reduction range 64 as described above using the flat shield member 30, the shield member 30 having a length d'=a'+2·c' in the longitudinal direction Y is required. However, c'=b'·tan θ'. That is, the shield member 39 according to this modified example can form the same magnetic field reduction range with a size shorter by 2·c′ in the longitudinal direction Y than the flat shield member 30 .

As described above, the shield member may cover the core material from the side opposite to the partition body with the core material sandwiched therebetween, and cover the end portion of the core material from at least one side in the longitudinal direction of the core material. can take any shape and arrangement. The necessary shape and arrangement may be determined by experiments according to the area where leakage prevention is required.

DESCRIPTION OF SYMBOLS 10... 1st core material, 20... 2nd core material, 32, 36, 39... Shield member, 32a... First shield part, 32b, 34b... Second shield part, 36c Third shield part 40 Partition body 70a Connection part 100 Power transmission unit 200, 210, 220, 240, 260, 280, 290 Power reception unit.

Claims (5)

An electric unit constituting one of a power receiving unit and a power transmitting unit used in a wireless power supply device,
an elongated core member disposed on one side in the wall thickness direction of a partition disposed between the power receiving unit and the power transmitting unit, and around which a coil is wound;
a shield member;
The shield member is
a first shield portion disposed on the side opposite to the partition body with the core material interposed therebetween;
a second shield part that covers the end of the core material from one side in the longitudinal direction of the core material ,
The wireless power supply device is applied to a power supply system for a motor that drives an electric shutter housed in a shutter box containing a motor or an electronic circuit,
The electric unit, wherein the power receiving unit is installed between the shutter box and the partition . 2. The electric unit according to claim 1, wherein the second shield portion has a connection portion to which a fixing member used for fixing the shield member to the partition is connected. The shield member has a third shield portion extending in an in-plane direction of the partition from an end portion of the second shield portion on the side of the partition,
2. The electric unit according to claim 1, wherein the third shield part is used for fixing the shield member to the partition. The power transmission unit includes an elongated first core material around which a coil is wound,
The length of the first shield part is a,
the length of the second shield portion is b;
d is the length when the first shield part and the second shield part are composed of one elongated member,
An imaginary line passing through one end in the longitudinal direction of the first core member and one end in the longitudinal direction of the shield member is Lc;
Ld is an imaginary line passing through the other longitudinal end of the first core member and the other longitudinal end of the shield member;
When the angle formed by the virtual line Lc and the virtual line Ld with the wall thickness direction of the partition is θ,
d=a+2b·tan θ
4. The electric unit according to any one of claims 1 to 3, characterized in that: An electric unit constituting one of a power receiving unit and a power transmitting unit used in a wireless power supply device,
an elongated core member disposed on one side in the wall thickness direction of a partition disposed between the power receiving unit and the power transmitting unit, and around which a coil is wound;
a shield member;
The shield member covers the core material from a side opposite to the partition body with the core material sandwiched therebetween, and covers an end portion of the core material from at least one side in the longitudinal direction of the core material ,
The wireless power supply device is applied to a power supply system for a motor that drives an electric shutter housed in a shutter box containing a motor or an electronic circuit,
The electric unit, wherein the power receiving unit is installed between the shutter box and the partition .

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