KR20210061720A - Wireless charging pad, wireless charging device, and electric vehicle comprising same - Google Patents

Abstract

According to an embodiment of the present invention, provided is a wireless charging pad which can improve charging efficiency and heat dissipation characteristics by applying a three-dimensional structure to a magnetic material. To this end, the wireless charging pad comprises a coil, a shield unit, and a first magnetic material. Accordingly, the wireless charging pad and a wireless charging device using a structure thereof can be usefully used in electric vehicles which require large-capacity power transmission between a transmitter and a receiver.

Description

Wireless charging pad, wireless charging device, and electric vehicle including the same {WIRELESS CHARGING PAD, WIRELESS CHARGING DEVICE, AND ELECTRIC VEHICLE COMPRISING SAME}

The embodiment relates to a wireless charging pad, a wireless charging device, and an electric vehicle including the same. More specifically, the embodiment relates to a wireless charging pad, a wireless charging device, and an electric vehicle including the same, in which charging efficiency is improved by applying a heat dissipation structure.

Today, the field of information and communication is developing at a very fast pace, and various technologies in which electricity, electronics, communication, semiconductors, etc. are comprehensively combined are continuously being developed. In addition, as the tendency of electronic devices to become mobile is increasing, research on wireless communication and wireless power transmission technology is being actively conducted in the communication field. In particular, research on a method of wirelessly transmitting power to electronic devices and the like has been actively conducted.

In the wireless power transmission, power is wirelessly transmitted through space using an electromagnetic field resonance structure such as inductive coupling, capacitive coupling, or an antenna without physical contact between a transmitter supplying power and a receiver receiving power. To transfer. The wireless power transmission is suitable for portable communication devices, electric vehicles, etc. that require a large-capacity battery, and since the contact point is not exposed, there is little risk of a short circuit, and a wired charging failure phenomenon can be prevented.

Meanwhile, as interest in electric vehicles has recently increased, interest in building a charging infrastructure is increasing. Various charging methods such as battery replacement, rapid charging device, and wireless charging device have already appeared, including charging electric vehicles using household chargers, and a new charging business business model has also begun to appear (see Korean Patent Laid-Open Patent No. 2011-0042403). In addition, in Europe, electric vehicles and charging stations in test operation have begun to stand out, and in Japan, electric vehicles and charging stations are being piloted, led by automobile manufacturers and power companies.

Korean Patent Application Publication No. 2011-0042403

A conventional wireless charging pad used in an electric vehicle, etc., referring to FIG. 3, a magnetic material 300 ′ is disposed adjacent to the coil 200 ′ to improve wireless charging efficiency, and a shield part 400 for electromagnetic shielding. ') is disposed to be spaced apart from the magnetic material 300' by a predetermined interval.

The wireless charging pad generates heat during the wireless charging operation due to the resistance of the coil and the magnetic loss of the magnetic material. In particular, the magnetic material in the wireless charging pad generates heat near the coil with high electromagnetic wave energy density, and the generated heat changes the magnetic properties of the magnetic material, causing impedance mismatch between the transmitting pad and the receiving pad, reducing charging efficiency. There was a problem that the fever became worse again due to this. However, since such a wireless charging pad is installed in the lower part of an electric vehicle, it is difficult to implement a heat dissipation structure because it adopts a sealed structure for dustproof, waterproof and shock absorption.

Accordingly, as a result of research by the present inventors, it was found that charging efficiency and heat dissipation characteristics can be improved by applying a three-dimensional structure to a magnetic material used for a wireless charging pad.

Accordingly, the object of the embodiment is to provide a wireless charging pad, a wireless charging device, and an electric vehicle including the same, in which charging efficiency and heat dissipation characteristics are improved by applying a magnetic material having a three-dimensional structure.

According to one embodiment, a coil including a conductive wire; A shield part disposed on the coil; And a first magnetic material disposed between the coil and the shield part, wherein an area corresponding to the coil in the first magnetic material is defined as a first area, and other areas are defined as a second area. , A wireless charging pad is provided in which the first region of the first magnetic material has a thicker thickness than that of the second region.

According to another embodiment, a housing; A coil disposed within the housing and including a conductive wire; A shield part disposed on the coil; And a first magnetic material disposed between the coil and the shield part, wherein an area corresponding to the coil in the first magnetic material is defined as a first area, and other areas are defined as a second area. , A wireless charging device is provided in which the first region of the first magnetic material has a thicker thickness than that of the second region.

According to another embodiment, an electric vehicle including the wireless charging device according to the embodiment is provided.

According to the above embodiment, charging efficiency and heat dissipation characteristics may be improved by applying a three-dimensional structure to a magnetic material used for a wireless charging pad.

Specifically, according to the embodiment, the thickness of the magnetic material at the rear of the coil where electromagnetic energy is concentrated during wireless charging is increased, and the thickness of the magnetic material in the center of the center having a relatively low electromagnetic energy density is reduced, thereby increasing wireless charging efficiency while increasing the efficiency of the magnetic material. You can lower the heat generated.

Accordingly, the wireless charging pad and the wireless charging device employing the structure thereof may be usefully used in an electric vehicle that requires a large amount of power transmission between a transmitter and a receiver.

1 shows a configuration diagram of a wireless charging pad according to an embodiment.
2A to 2C are cross-sectional views of a wireless charging device according to an embodiment.
3 shows a configuration diagram of a conventional wireless charging pad.
4 shows an electric vehicle to which a wireless charging device is applied as a receiver.

In the description of the following embodiments, it is described that one component is formed above or below another component, in which one component is directly above or below another component, or indirectly through another component. It includes all that are formed by.

In addition, standards for the top/bottom of each component will be described based on the drawings. The size of each component in the drawings may be exaggerated for description, and may be different from the size that is actually applied.

In the present specification, "including" a certain element means that other elements may not be excluded, and other elements may be further included, unless otherwise specified.

In addition, all numerical ranges representing characteristic values, dimensions, and the like of components described in the present specification are to be understood as being modified by the term "about" in all cases unless otherwise specified.

In the present specification, unless otherwise specified, the singular expression should be interpreted as a meaning including the singular or plural interpreted in context.

[Wireless charging pad]

1 shows a configuration diagram of a wireless charging pad according to an embodiment.

Referring to FIG. 1, a wireless charging pad 10 according to an embodiment includes a coil 200 including a conductive wire; A shield part 400 disposed on the coil 200; And a first magnetic material 300 disposed between the coil 200 and the shield part 400, and an area corresponding to the coil in the first magnetic material 300 is defined as a first area 310 When the other area is defined as the second area 320, the first area 310 of the first magnetic material has a thicker thickness than the second area 320.

Hereinafter, each component of the wireless charging pad will be described in detail.

Support plate

The wireless charging pad 10 may further include a support plate 100 supporting the coil 200. The material and structure of the support plate may be a material and structure of a conventional support plate used for a wireless charging pad. The support plate may have a flat plate structure or a structure in which grooves are formed along the coil shape to fix the coil.

coil

The coil includes a conductive wire.

The conductive wire includes a conductive material. For example, the conductive wire may include a conductive metal. Specifically, the conductive wire may include at least one metal selected from the group consisting of copper, nickel, gold, silver, zinc, and tin.

In addition, the conductive wire may have an insulating sheath. For example, the insulating shell may include an insulating polymer resin. Specifically, the insulating shell may include polyvinyl chloride (PVC) resin, polyethylene (PE) resin, Teflon resin, silicone resin, polyurethane resin, and the like.

The diameter of the conductive wire may be, for example, in the range of 1 mm to 10 mm, in the range of 1 mm to 5 mm, or in the range of 1 mm to 3 mm.

The conductive wire may be wound in a flat coil shape. Specifically, the planar coil may include a planar spiral coil. In addition, the planar shape of the coil may be an oval shape, a polygonal shape, or a polygonal shape having rounded corners, but is not particularly limited.

The outer diameter of the flat coil may be 5 cm to 100 cm, 10 cm to 50 cm, 10 cm to 30 cm, 20 cm to 80 cm, or 50 cm to 100 cm. As a specific example, the planar coil may have an outer diameter of 10 cm to 50 cm.

In addition, the inner diameter of the flat coil may be 0.5 cm to 30 cm, 1 cm to 20 cm, or 2 cm to 15 cm.

The number of windings of the flat coil may be 5 to 50 times, 10 to 30 times, 5 to 30 times, 15 to 50 times, or 20 to 50 times. As a specific example, the planar coil may be formed by winding the conductive wire 10 to 30 times.

In addition, the spacing between the conductive wires in the planar coil shape may be 0.1 cm to 1 cm, 0.1 cm to 0.5 cm, or 0.5 cm to 1 cm.

When it is within the above-described desirable planar coil dimensions and specifications, it may be suitable for a field requiring large-capacity power transmission, such as an electric vehicle.

Shield part

The shield part is disposed on the coil.

The shield unit suppresses electromagnetic interference (EMI) that may occur due to leakage of electromagnetic waves to the outside through electromagnetic wave shielding.

The shield portion may be disposed to be spaced apart from the coil by a predetermined distance. For example, the separation distance between the shield part and the coil may be 10 mm or more or 15 mm or more, and specifically 10 mm to 30 mm, or 10 mm to 20 mm.

The material of the shield part may be, for example, metal, and accordingly, the shield part may be a metal plate, but is not particularly limited.

As a specific example, the material of the shield unit may be aluminum, and other metal or alloy material having electromagnetic wave shielding ability may be used.

The thickness of the shield portion may be 0.2 mm to 10 mm, 0.5 mm to 5 mm, or 1 mm to 3 mm. In addition, an area of the shield part may be 200 cm ² or more, 400 cm ² or more, or 600 cm ² or more.

First magnetic material

The first magnetic material is disposed between the coil and the shield part.

The first magnetic material may be disposed to be spaced apart from the coil by a predetermined distance. For example, the separation distance between the first magnetic material and the coil may be 0.2 mm or more, 0.5 mm or more, 0.2 mm to 3 mm, or 0.5 mm to 1.5 mm.

In addition, the first magnetic material may be disposed to be spaced apart from the shield part by a predetermined distance. For example, a separation distance between the first magnetic material and the shield unit may be 3 mm or more, 5 mm or more, 3 mm to 10 mm, or 4 mm to 7 mm.

Alternatively, a part of the first magnetic material may contact the shield part. For example, as shown in FIG. 2A, the first region 310 of the first magnetic material 300 may contact the shield part 400. Specifically, at least a portion of the first region of the first magnetic material may contact the shield part. Alternatively, all of the first regions of the first magnetic material may contact the shield part. In this case, the second area of the first magnetic material may not contact the shield part.

Three-dimensional structure of the first magnetic material

According to the above embodiment, charging efficiency and heat dissipation characteristics may be improved by applying a three-dimensional structure to the first magnetic material. That is, when an area corresponding to the coil in the first magnetic material is defined as a first area and the other area is defined as a second area, the first area of the first magnetic material is compared to the second area. It has a thicker thickness. In this case, in the first magnetic material, the first region and the second region may be integrally formed with each other.

In this way, by increasing the thickness of the magnetic material on the rear side of the coil where electromagnetic energy is concentrated during wireless charging, and by lowering the thickness of the magnetic material in the center, which has a relatively low electromagnetic energy density, the electromagnetic wave concentrated around the coil is effectively focused and charging efficiency is improved. In addition to the improvement, the distance between the coil and the shield unit can be steadily maintained without a separate spacer, so that the material cost and process cost due to the use of the spacer or the like can be reduced.

In the first magnetic material, the first region may have a thickness that is 1.5 times or more thicker than that of the second region. In the case of the above thickness ratio, it is possible to improve charging efficiency by more effectively focusing electromagnetic waves concentrated around the coil, and is advantageous in heat generation and weight reduction. Specifically, the thickness ratio of the first region/second region in the first magnetic material may be 2 or more, 3 or more, or 5 or more. In addition, the thickness ratio may be 100 or less, 50 or less, 30 or less, or 10 or less. More specifically, the thickness ratio may be 1.5 to 100, 2 to 50, 3 to 30, or 5 to 10.

The thickness of the first region of the first magnetic material may be 1 mm or more, 3 mm or more, or 5 mm or more, and may be 30 mm or less, 20 mm or less, or 11 mm or less. In addition, the thickness of the second region of the first magnetic material may be 10 mm or less, 7 mm or less, or 5 mm or less, and may be 0 mm, 0.1 mm or more, or 1 mm or more. Specifically, the first region of the first magnetic material may have a thickness of 5 mm to 11 mm, and the second region may have a thickness of 0 mm to 5 mm.

In addition, the thickness of the second region of the first magnetic material may be zero. That is, as shown in FIG. 2B, the first magnetic material 300 may have an empty shape in the second region 320. In this case, the first magnetic material can effectively improve charging efficiency even in a smaller area.

Area and thickness of the first magnetic material

The first magnetic material may have a large area, and specifically, may have an area of 200 cm ² or more, 400 cm ² or more, or 600 cm ² or more. In addition, the first magnetic material may have an area of ^{10,000 cm 2 or less.}

The large-area first magnetic material may be composed of a combination of a plurality of unit magnetic materials, in which case the area of the unit magnetic material may be 60 cm ² or more, 90 cm ² , or 95 cm ² to 900 cm ² have.

Alternatively, the first magnetic material may have an empty shape in the second area, and in this case, the first magnetic material may have an area of the first area, that is, an area corresponding to the coil.

The first magnetic material may be a magnetic block manufactured by a method such as molding through a mold. For example, the first magnetic material may be molded into a three-dimensional structure through a mold. Such a magnetic sheet may be formed into a three-dimensional structure by mixing magnetic powder and a binder resin and injecting it into a mold by injection molding or the like.

Alternatively, the first magnetic material may be a stack of magnetic sheets, for example, 20 or more magnetic sheets, or 50 or more magnetic sheets.

Specifically, the stacked body of the magnetic sheet may be one or more additional magnetic sheets stacked only in the second region of the first magnetic material.

In this case, the thickness of the individual magnetic sheet may be 80 µm or more, or 85 µm to 150 µm. Such a magnetic sheet may be manufactured by a conventional sheet forming process such as mixing magnetic powder and a binder resin into a slurry, forming a sheet, and curing.

Magnetic powder

The first magnetic material may include a binder resin and magnetic powder dispersed in the binder resin.

Accordingly, in the first magnetic material, magnetic powders are bonded to each other by the binder resin, so that defects may be reduced over a large area and damage due to impact may be reduced.

The magnetic powder may be an oxide-based magnetic powder such as ferrite (Ni-Zn-based, Mg-Zn-based, Mn-Zn-based ferrite, etc.); Metallic magnetic powder such as permalloy, sanddust, and nanocrystalline magnetic material; Or it may be a mixture of these powders. More specifically, the magnetic powder may be sandblast particles having an Fe-Si-Al alloy composition.

As an example, the magnetic powder may have a composition represented by Formula 1 below.

[Formula 1]

Fe _1-abc Si _a X _b Y _c

In the above formula, X is Al, Cr, Ni, Cu, or a combination thereof; Y is Mn, B, Co, Mo, or a combination thereof; 0.01 ≤ a ≤ 0.2, 0.01 ≤ b ≤ 0.1, and 0 ≤ c ≤ 0.05.

The average particle diameter of the magnetic powder may be in the range of about 3 nm to about 1 mm, about 1 µm to 300 µm, about 1 µm to 50 µm, or about 1 µm to 10 µm.

The first magnetic material may contain the magnetic powder in an amount of 50% by weight or more, 70% by weight or more, or 85% by weight or more.

For example, the first magnetic material comprises 50% to 99% by weight, 70% to 95% by weight, 70% to 90% by weight, 75% to 90% by weight, and 75% by weight of the magnetic powder. It may be included in an amount of 95% by weight, 80% by weight to 95% by weight, or 80% by weight to 90% by weight.

Binder resin

The binder resin may be a curable resin. Specifically, the binder resin may include a photocurable resin, a thermosetting resin, and/or a high heat-resistant thermoplastic resin, and preferably a thermosetting resin.

As a resin capable of being cured and exhibiting adhesiveness as described above, it includes at least one functional group or moiety capable of curing by heat such as a glycidyl group, an isocyanate group, a hydroxyl group, a carboxyl group or an amide group; Or it contains one or more functional groups or moieties that can be cured by active energy such as an epoxide group, a cyclic ether group, a sulfide group, an acetal group or a lactone group. You can use the resin. Such a functional group or moiety may be, for example, an isocyanate group, a hydroxyl group, or a carboxyl group.

Specifically, the curable resin may be a polyurethane resin, an acrylic resin, a polyester resin, an isocyanate resin, or an epoxy resin having at least one or more functional groups or moieties as described above, but is not limited thereto.

As an example, the binder resin may include a polyurethane-based resin, an isocyanate-based curing agent, and an epoxy-based resin.

The first magnetic material may contain the binder resin in an amount of 5 wt% to 40 wt%, 5 wt% to 20 wt%, 5 wt% to 15 wt%, or 7 wt% to 15 wt%.

In addition, the first magnetic material is, based on its weight, as the binder resin, 6% to 12% by weight of a polyurethane-based resin, 0.5% to 2% by weight of a isocyanate-based curing agent, and 0.3% to 1.5% by weight. It may contain an epoxy-based resin by weight.

Magnetic properties of the first magnetic material

The first magnetic material may have a certain level of magnetic properties in the vicinity of a standard frequency for wireless charging of an electric vehicle.

The standard frequency of wireless charging of the electric vehicle may be less than 100 kHz, for example, 79 kHz to 90 kHz, specifically 81 kHz to 90 kHz, and more specifically about 85 kHz, which may be used in mobile electronic devices such as mobile phones. It is a band that is distinct from the applied frequency.

In the frequency band of 79 kHz to 90 kHz of the first magnetic material, the permeability may vary depending on the material, but may be 5 or more, for example, 5 to 150,000, and 5 to 300, 500 to 3,500, or 10,000 depending on the specific material. To 150,000. In addition, the investment loss in the frequency band of 79 kHz to 90 kHz of the first magnetic material may vary depending on the material, but may be 0 or more, for example, 0 to 50,000, and 0 to 1,000, 1 to 100, depending on the specific material. It may be 100 to 1,000, or 5,000 to 50,000.

As a specific example, when the first magnetic material is a polymer-type magnetic block containing magnetic powder and a binder resin, the magnetic permeability may be 5 to 130, 15 to 80, or 10 to 50 in a frequency band of 79 kHz to 90 kHz. In addition, the investment loss may be 0 to 20, 0 to 15, or 0 to 5.

Characteristics of the first magnetic material

The first magnetic material may be elongated at a predetermined rate. For example, the elongation rate of the first magnetic material may be 0.5% or more. The elongation property is difficult to obtain in a ceramic-based magnetic material that does not apply a polymer, and damage can be reduced even if a large-area magnetic material is distorted due to impact. Specifically, the elongation rate of the first magnetic material may be 0.5% or more, 1% or more, or 2.5% or more. There is no particular limitation on the upper limit of the elongation, but when the content of the polymer resin is increased to improve the elongation, since properties such as inductance of the magnetic material may be deteriorated, the elongation is preferably 10% or less.

The first magnetic material has a small rate of change in properties before and after impact, and is superior to a general sintered ferrite magnetic sheet.

In the present specification, the rate of change in properties before and after impact (%) can be calculated by the following equation.

Characteristic change rate (%)=|characteristic value before impact-characteristic value after impact|/characteristic value before impact×100

For example, the first magnetic material may have an inductance change rate of less than 5% or less than 3% before and after an impact applied by free fall from a height of 1 m. More specifically, the inductance change rate may be 0% to 3%, 0.001% to 2%, or 0.01% to 1.5%. When within the above range, the rate of change of inductance before and after impact is relatively small, so that the stability of the magnetic material may be further improved.

In addition, the first magnetic material may have a rate of change of the quality factor (Q factor) before and after the impact applied by free falling from a height of 1 m from 0% to 5%, from 0.001% to 4%, or from 0.01% to 2.5%. . When within the above range, there is little change in properties before and after impact, so that the stability and impact resistance of the magnetic material may be more improved.

In addition, the first magnetic material may have a resistance change rate of 0% to 2.8%, 0.001% to 1.8%, or 0.1% to 1.0% before and after the impact applied by free fall from a height of 1 m. When within the above range, even if repeatedly applied in an environment where actual shock and vibration are applied, the resistance value can be well maintained below a certain level.

In addition, the first magnetic material may have a rate of change of charging efficiency before and after the impact applied by free fall from a height of 1 m from 0% to 6.8%, from 0.001% to 5.8%, or from 0.01% to 3.4%. When it is within the above range, even if the large-area magnetic material repeatedly experiences impact or warping, the characteristics can be more stably maintained.

Second magnetic material

The wireless charging pad according to the embodiment may include an additional second magnetic material in addition to the first magnetic material, thereby improving charging efficiency and heat dissipation characteristics. Specifically, as shown in FIG. 2C, a second magnetic material 500 disposed on the first region 310 of the first magnetic material 300 may be additionally included.

The second magnetic material may be disposed on one surface of the shield portion facing the first magnetic material. That is, the second magnetic material may be disposed between the shield part and the first magnetic material.

For example, the second magnetic material may be attached to one surface of the shield part, so that heat generated from the second magnetic material may be effectively discharged through the shield part. Specifically, the second magnetic material is attached to one surface of the shield portion with a thermally conductive adhesive, thereby further enhancing a heat dissipation effect.

The thermally conductive adhesive may include a thermally conductive material such as metal, carbon, ceramic, etc., and may be, for example, an adhesive resin in which thermally conductive particles are dispersed.

The second magnetic material may be disposed to be spaced apart from the first magnetic material by a predetermined distance. For example, the separation distance between the first magnetic material and the second magnetic material is 1 mm or more, 2 mm or more, 1 mm to 10 mm, 2 mm to 7 mm, 3 mm to 5 mm, or 5 mm to 10 mm Can be

The second magnetic material may have a sheet shape or a ribbon shape. The second magnetic material may have the same area as or different from the first magnetic material.

For example, the second magnetic material may have the same large area as the first magnetic material. Specifically, the area of the second magnetic material may be 200 cm ² or more, 400 cm ² or more, or 600 cm ² or more. In addition, the area of the second magnetic material ^{may be 10,000 cm 2} or less.

Alternatively, the second magnetic material may have an area smaller than that of the first magnetic material. For example, when the second magnetic material is disposed only on the first area of the first magnetic material, the second magnetic material may have an area corresponding to the area of the first area. In addition, accordingly, the second magnetic material may be disposed to correspond to an area in which the coil is present, and may have an area corresponding to the area of the coil. In this case, the second magnetic material can effectively improve charging efficiency and heat dissipation characteristics even with a small area.

Characteristics of the second magnetic material

The second magnetic material may have a specific range of magnetic properties in the vicinity of a standard frequency for wireless charging of an electric vehicle.

For example, in the frequency band of 79 kHz to 90 kHz of the second magnetic material, the permeability may vary depending on the material, but may be 5 or more, for example, 5 to 150,000, and 5 to 300, 500 to 3,500 depending on the specific material. , Or 10,000 to 150,000. In addition, the investment loss in the frequency band of 79 kHz to 90 kHz of the second magnetic material may vary depending on the material, but may be 0 or more, for example, 0 to 50,000, and 0 to 1,000, 1 to 100, depending on the specific material. It may be 100 to 1,000, or 5,000 to 50,000.

As a specific example, when the second magnetic material is a nanocrystalline magnetic material, the magnetic permeability in the frequency band of 79 kHz to 90 kHz may be 500 to 3,000, or 10,000 to 150,000, and the investment loss is 100 to 1,000. , Or 8,000 to 50,000.

Preferably, the second magnetic material has a relatively high magnetic permeability compared to the first magnetic material, thereby improving the charging efficiency of the wireless charging pad. For example, the second magnetic material may have a high magnetic permeability at 79 kHz to 90 kHz compared to the first magnetic material. Specifically, the difference in permeability between the second magnetic material and the first magnetic material at 79 kHz to 90 kHz may be 100 or more, 500 or more, 1,000 or more, or 10,000 or more, and specifically 100 to 200,000, 500 to 50,000, Or 1,000 to 10,000.

In wireless charging, the magnetic flux density is higher as it approaches the coil, but when the magnetic material is around the coil, the magnetic flux is focused on the magnetic material, and if there is more than one magnetic material, the magnetic flux density increases in the order of the magnetic permeability. You lose. Therefore, if the second magnetic material having a higher magnetic permeability than the first magnetic material is properly disposed, the magnetic flux can be effectively distributed.

In addition, the horizontal thermal conductivity of the second magnetic material may be 1 W/m·K or more, for example, 1 W/m·K to 30 W/m·K, or 10 W/m·K to 20 W/m· Can be K. In addition, the vertical thermal conductivity of the second magnetic material may be 0.1 W/m·K or more, for example, 0.1 W/m·K to 2 W/m·K, or 0.5 W/m·K to 1.5 W/m· Can be K. Specifically, the second magnetic material may have a horizontal thermal conductivity of 1 W/m·K to 30 W/m·K and a vertical thermal conductivity of 0.1 W/m·K to 2 W/m·K.

Accordingly, heat generated during wireless charging due to an investment loss in the second magnetic material may be discharged through a shield portion adjacent to the second magnetic material.

Composition of the second magnetic material

The second magnetic material may include a metallic magnetic material.

The second magnetic material may include a nanocrystalline magnetic material.

When the nanocrystalline magnetic material is applied as the second magnetic material, the coil's quality factor (Q factor: Ls) decreases even though the inductance (Ls) of the coil decreases as the distance from the coil increases. /Rs) increases, which can improve charging efficiency and reduce heat generation.

For example, the second magnetic material may be an Fe-based nanocrystalline magnetic material, and specifically, Fe-Si-Al-based nanocrystalline magnetic material, Fe-Si-Cr-based nanocrystalline magnetic material, or Fe- It may be a Si-B-Cu-Nb-based nanocrystalline magnetic material.

More specifically, the second magnetic material may be a Fe-Si-B-Cu-Nb-based nanocrystalline magnetic material, in which case, Fe is 70% to 85%, and the sum of Si and B is 10 % To 29 element%, and the sum of Cu and Nb may be 1 element% to 5 element% (here, element% means the percentage of the number of specific elements relative to the total number of elements constituting the magnetic material). In the above composition range, an Fe-Si-B-Cu-Nb-based alloy can be easily formed into a nanocrystalline magnetic material by heat treatment.

Second magnetic material manufacturing method

The nanocrystalline magnetic material is prepared by, for example, a rapid cooling solidification method (RSP) by melt spinning of an Fe-based alloy, and is non-magnetic for 30 minutes to 2 hours at a temperature range of 300°C to 700°C to obtain a desired magnetic permeability. It can be manufactured by performing intestinal heat treatment.

If the heat treatment temperature is less than 300°C, nanocrystals are not sufficiently formed, so that the desired permeability is not obtained, and the heat treatment time may take a long time, and if the heat treatment temperature exceeds 700°C, the permeability may be significantly lowered by superheat treatment. In addition, when the heat treatment temperature is low, it takes a long treatment time, and on the contrary, if the heat treatment temperature is high, the treatment time is preferably shortened.

The nanocrystalline magnetic material is difficult to make a thick thickness in the manufacturing process, and may be formed as a thin film sheet having a thickness of, for example, 15 μm to 35 μm. Therefore, it is possible to form a magnetic material by stacking several such thin-film sheets. In this case, an adhesive layer such as an adhesive tape may be inserted between the thin film sheets. In addition, the magnetic material may be crushed by a pressure roll or the like at a later stage of the manufacturing process to form a plurality of cracks in the thin film sheet, thereby manufacturing a plurality of nanocrystalline fine pieces.

[Wireless charging device]

2A to 2C are cross-sectional views of a wireless charging device according to an embodiment. 2A to 2C, the wireless charging device 11 according to an embodiment includes a housing 600; A coil 200 disposed in the housing 600 and including a conductive wire; A shield part 400 disposed on the coil 200; And a first magnetic material 300 disposed between the coil 200 and the shield part 400, and an area corresponding to the coil 200 in the first magnetic material 300 is a first area. When defined as 310 and the other regions are defined as the second region 320, the first region 310 of the first magnetic material has a thicker thickness than the second region 320.

The housing allows components such as the coil, shield unit, and magnetic material to be properly disposed and assembled. The material and structure of the housing may be a material and structure of a conventional housing used in a wireless charging device.

The wireless charging device according to the embodiment may further include a support plate supporting the coil. The configuration and characteristics of the support plate, coil, shield unit, and magnetic material of the wireless charging device are the same as described in the wireless charging pad. Accordingly, the wireless charging device substantially includes the configuration and characteristics of the wireless charging pad.

In addition, the wireless charging device according to the embodiment may further include a spacer for securing a space between the shield unit and the magnetic material. The material and structure of the spacer may be a material and structure of a conventional housing used in a wireless charging device.

The wireless charging device may improve charging efficiency and heat dissipation characteristics by applying a three-dimensional structure to a magnetic material. Accordingly, the wireless charging device may be usefully used in an electric vehicle that requires large-capacity power transmission between a transmitter and a receiver.

[Electric car]

4 shows an electric vehicle to which a wireless charging device is applied.

The electric vehicle may be wirelessly charged in a parking area equipped with a wireless charging system for an electric vehicle.

Referring to FIG. 4, an electric vehicle 1 according to an embodiment includes a wireless charging device according to the embodiment as a receiver 21.

The wireless charging device serves as a receiver 21 for wireless charging of the electric vehicle 1 and may receive power from the transmitter 22 for wireless charging.

Specifically, the electric vehicle includes a wireless charging device, and the wireless charging device includes a housing; A coil disposed within the housing and including a conductive wire; A shield part disposed on the coil; And a first magnetic material disposed between the coil and the shield part, wherein an area corresponding to the coil in the first magnetic material is defined as a first area, and other areas are defined as a second area. , The first region of the first magnetic material has a thicker thickness than that of the second region.

The configuration and characteristics of each component of the wireless charging device included in the electric vehicle are as described above.

The wireless charging device may be provided under the vehicle.

The electric vehicle may further include a battery receiving power from the wireless charging device. The wireless charging device may receive power wirelessly and transmit it to the battery, and the battery may supply power to a drive system of the electric vehicle. The battery may be charged by power delivered from the wireless charging device or other additional wired charging device.

In addition, the electric vehicle may further include a signal transmitter for transmitting information on charging to a transmitter of a wireless charging system for an electric vehicle. Information on such charging may include charging efficiency such as charging speed, charging status, and the like.

1: electric vehicle, 10, 10': wireless charging pad,
11: wireless charging device,
21: receiver, 22: transmitter,
100, 100': support plate, 200, 200': coil,
300: first magnetic material, 300': magnetic material,
310: a first area, 320: a second area,
400, 400': shield part, 500: second magnetic material,
600: housing.

Claims (11)

A coil including a conductive wire;
A shield part disposed on the coil; And
Including a first magnetic material disposed between the coil and the shield,
In the first magnetic material, when an area corresponding to the coil is defined as a first area and the other area is defined as a second area, the first area of the first magnetic material is thicker than the second area. With a thickness, wireless charging pad.
The method of claim 1,
The wireless charging pad of the first magnetic material, wherein the first region has a thickness that is at least 1.5 times thicker than that of the second region.
The method of claim 2,
The wireless charging pad, wherein the first region of the first magnetic material has a thickness of 5 mm to 11 mm, and the second region has a thickness of 0 mm to 5 mm.
The method of claim 1,
The wireless charging pad, wherein the first magnetic material comprises a binder resin and magnetic powder dispersed in the binder resin.
The method of claim 1,
At least a portion of the first region of the first magnetic material contacts the shield part.
The method of claim 1,
The wireless charging pad, wherein the first magnetic material has an empty shape in the second area.
The method of claim 1,
The first magnetic material is molded in a three-dimensional structure through a mold, wireless charging pad.
The method of claim 1,
The wireless charging pad further comprises a second magnetic material disposed on the first area of the first magnetic material.
The method of claim 8,
The wireless charging pad, wherein the second magnetic material comprises a nanocrystalline magnetic material.
housing;
A coil disposed within the housing and including a conductive wire;
A shield part disposed on the coil; And
Including a first magnetic material disposed between the coil and the shield,
In the first magnetic material, when an area corresponding to the coil is defined as a first area and the other area is defined as a second area, the first area of the first magnetic material is thicker than the second area. With a thickness, wireless charging device.
An electric vehicle comprising the wireless charging device of claim 10.

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