KR102341787B1 - Wireless charging device and vehicle comprising same - Google Patents

Abstract

The wireless charging device according to an embodiment may distribute the magnetic flux focused when the coil unit receives wireless power from the outside in a desired direction by using two or more hybrid magnetic units having different calorific values, in particular, the first one of the magnetic units. By arranging the second magnetic part having a larger heating value when the coil part receives wireless power from the outside compared to the magnetic part close to the shield part, while effectively distributing magnetic flux density and heat emission to increase wireless charging efficiency, in the second magnetic part Heat dissipation characteristics can be efficiently improved by dissipating the generated heat through the shield unit. Accordingly, the wireless charging device may be usefully used in an electric vehicle requiring large-capacity power transmission between a transmitter and a receiver.

Description

WIRELESS CHARGING DEVICE AND VEHICLE COMPRISING SAME

The embodiment relates to a wireless charging device and a mobile means comprising the same. More specifically, the embodiment relates to a wireless charging device with improved charging efficiency by applying a heat dissipation structure, and a moving means including the same.

Recently, as interest in electric vehicles has rapidly increased, interest in building charging infrastructure is increasing. Various charging methods such as electric vehicle charging using home chargers, battery replacement, fast charging devices, and wireless charging devices have already appeared, and new charging business models have also begun to appear (refer to Korean Patent Application Laid-Open No. 2011-0042403). In addition, electric vehicles and charging stations under test operation are starting to stand out in Europe, and in Japan, car manufacturers and electric power companies are piloting electric vehicles and charging stations.

In a conventional wireless charging device used for electric vehicles, etc., a magnetic part is disposed adjacent to a coil part to improve wireless charging efficiency, and a shield part (metal plate) for shielding is disposed spaced apart from the magnetic part by a predetermined interval.

The wireless charging device generates heat by the resistance of the coil part and the magnetic loss of the magnetic part during the wireless charging operation. In particular, the magnetic unit in the wireless charging device generates heat in a portion close to the coil unit with high electromagnetic wave energy density, and the generated heat changes the magnetic properties of the magnetic unit to cause an impedance mismatch between the transmitting pad and the receiving pad, thereby lowering charging efficiency, As a result, there was a problem in that the heat was intensified again.

In particular, in the conventional wireless charging device, the magnetic part is mainly disposed between the sintered ferrite sheet and the coil part and the shield part, especially on one surface close to the coil part. The sintered ferrite sheet has low impact resistance and heavy specific gravity. If it is placed close to the coil part, heat is generated from the coil part and the sintered ferrite sheet during charging. In particular, the heat generated from the sintered ferrite sheet is air with low thermal conductivity. Or it is difficult to transmit and dissipate heat to the spacer part. Accordingly, the sintered ferrite sheet having an elevated temperature may have a problem in that the magnetic properties are lowered and the inductance value of the coil unit is changed accordingly, thereby lowering charging efficiency and causing more severe heat generation.

Korean Patent Publication No. 2011-0042403

The present invention is devised to solve the problems of the prior art.

The technical problem to be solved by the present invention is that when the coil unit receives wireless power from the outside, two or more types of hybrid magnetic units having different calorific values are used, but by placing them in consideration of their characteristics, charging efficiency and heat generation during wireless charging An object of the present invention is to provide a wireless charging device capable of improving the reduction characteristics.

Another technical problem to be solved by the present invention is to provide a moving means including the wireless charging device.

According to one embodiment, the coil unit; a first magnetic part disposed on the coil part; a second magnetic part disposed on the first magnetic part; and a shield portion disposed on the second magnetic portion, wherein when the coil portion receives wireless power from the outside, more heat is generated in the second magnetic portion than in the first magnetic portion is provided .

According to another embodiment, including a wireless charging device, the wireless charging device includes a coil unit; a first magnetic part disposed on the coil part; a second magnetic part disposed on the first magnetic part; and a shield portion disposed on the second magnetic portion, wherein when the coil portion receives wireless power from the outside, more heat is generated in the second magnetic portion than in the first magnetic portion, a moving means is provided .

According to the above embodiment, when the coil unit receives wireless power from the outside, two or more types of magnetic units having different calorific values are used, but by arranging them in consideration of their characteristics, heat generated during wireless charging can be reduced, and charging efficiency can be improved can be further improved.

Specifically, as the magnetic part, by using two or more hybrid type magnetic parts with different heating values, the magnetic flux that is focused during wireless charging can be distributed in a desired direction, and in particular, the coil part compared to the first magnetic part among the magnetic parts from the outside. By disposing the second magnetic part having a larger heating value when receiving wireless power close to the shield part, the heat generated from the second magnetic part is transferred through the shield part while effectively distributing magnetic flux density and heat emission to increase wireless charging efficiency. It is possible to efficiently improve heat dissipation characteristics by dissipating it.

Accordingly, the wireless charging device may be usefully used in a moving means such as an electric vehicle that requires large-capacity power transmission between a transmitter and a receiver.

1A and 1B are exploded perspective views of a wireless charging device according to an embodiment, respectively.
2A and 2B are perspective views of a wireless charging device according to the embodiment.
3A and 3B are cross-sectional views of the wireless charging device according to the embodiment.
3C and 3D are cross-sectional views of a wireless charging device according to another embodiment.
4 illustrates a process of forming a magnetic part through a mold according to an exemplary embodiment.
5 is a diagram illustrating a moving means (electric vehicle) having a wireless charging device according to an embodiment.

Hereinafter, specific embodiments for implementing the spirit of the present invention will be described in detail with reference to the drawings.

In addition, in the description of the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

In addition, in the accompanying drawings, some components are exaggerated, omitted, or schematically illustrated, and the size of each component does not fully reflect the actual size.

The terminology used herein is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise.

In this specification, like reference numerals refer to like elements.

In this specification, a component described as being formed above or below another component means that a component is formed directly above or below another component or indirectly through another component. include

In addition, the reference for the upper / lower of each component will be described with reference to the drawings. The size and thickness of each component in the drawings may be exaggerated for explanation, and may be different from the size actually applied.

Also, the meaning of “comprising,” as used herein, specifies a particular characteristic, region, integer, step, operation, element, and/or component, and other specific characteristic, region, integer, step, operation, element, component and It does not preclude the presence or addition of/or groups.

In addition, it should be understood that all numerical ranges indicating physical property values, dimensions, etc. of the components described in the present specification are modified by the term "about" in all cases unless otherwise specified.

In the present specification, unless otherwise specified, the expression “a” is interpreted as meaning including “a” or “plural” as interpreted in context.

[Wireless Charging Device]

1A and 1B are exploded perspective views of a wireless charging device according to an embodiment, FIGS. 2A and 2B are perspective views of a wireless charging device according to the embodiment, and FIGS. 3A and 3B are wireless charging according to the embodiment A cross-sectional view of each device is shown. In addition, Figures 3c and 3d is a cross-sectional view showing a wireless charging device according to another embodiment.

The drawings shown in FIGS. 1 to 3 are illustratively shown according to embodiments, and may be variously changed as long as the effects of the present invention are not impaired.

1A and 1B , a wireless charging device 10 according to an embodiment includes a coil unit 200; a first magnetic unit 300 disposed on the coil unit 200; a second magnetic part 500 disposed on the first magnetic part 300; and a shield unit 400 disposed on the second magnetic unit 500 , wherein when the coil unit 200 receives wireless power from the outside, the second magnetic unit 300 is higher than the first magnetic unit 300 . More heat is generated in the voice part 500 .

In general, when two or more types are used in combination as a hybrid type magnetic part, and these magnetic parts are simply stacked without special consideration, the magnetic flux is not properly distributed during wireless charging, so the transfer of heat generated to the outside is not effective. , and may be easily damaged by an external impact that may be applied while driving the vehicle.

According to one embodiment of the present invention, by using two or more types of hybrid magnetic parts having different calorific values, the magnetic flux focused during wireless charging can be distributed in a desired direction, and in particular, wireless charging compared to the first magnetic part among the magnetic parts. By disposing the second magnetic part having a larger heating value close to the shield part, the wireless charging efficiency is increased by effectively distributing magnetic flux density and heat emission, and heat generated from the second magnetic part is radiated through the shield part to dissipate heat. properties can be effectively improved.

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

coil part

A wireless charging device according to an embodiment of the present invention includes a coil unit through which an alternating current flows to generate a magnetic field.

The coil unit may include 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 a polyvinyl chloride (PVC) resin, a polyethylene (PE) resin, a Teflon resin, a silicone resin, a 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 the form of a flat coil. Specifically, the planar coil may include a planar spiral coil. In addition, the planar shape of the coil may be an elliptical shape, a polygonal shape, or a polygonal shape with rounded corners, but is not particularly limited.

The outer diameter of the planar 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 planar coil may be 0.5 cm to 30 cm, 1 cm to 20 cm, or 2 cm to 15 cm.

The number of turns 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 flat 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 preferred planar coil dimensions and standard ranges as described above, it may be suitable for a field requiring large-capacity power transmission, such as an electric vehicle.

The coil unit may be disposed to be spaced apart from the magnetic unit by a predetermined interval. For example, a distance between the coil unit and the magnetic unit 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.

magnetic part

The magnetic part may form a magnetic path of a magnetic field generated around the coil part, and is disposed between the coil part and the shield part.

Referring back to FIGS. 1A and 1B , the wireless charging device 10 may be two or more hybrid type magnetic units including a first magnetic unit 300 and a second magnetic unit 500 having different heating values. have.

Specifically, the first magnetic part 300 may be disposed on the coil part 200 , and the second magnetic part 500 may be disposed on the first magnetic part 300 , and the coil part When 200 receives wireless power from the outside, more heat may be generated in the second magnetic unit 500 than in the first magnetic unit 300 .

Since the hybrid magnetic part has different magnetic properties and heat output, depending on the method of arranging and combining them, the magnetic flux concentration during wireless charging can be distributed in the desired direction by using the tendency of the magnetic flux density to increase in the order of the magnetic permeability. In addition, it is possible to effectively dissipate heat to the outside by using the tendency that the amount of heat generated increases in proportion to the amount of magnetic flux and the size of the investment loss.

Therefore, according to an embodiment of the present invention, the second magnetic part 500 has a larger heat output during wireless charging compared to the first magnetic part 300 and is disposed closer to the shield part 400, By effectively distributing magnetic flux density and heat emission to increase wireless charging efficiency, heat generated from the second magnetic unit 500 may be radiated through the shield unit 400 to effectively improve heat dissipation characteristics.

In the wireless charging device according to an embodiment of the present invention, the magnetic unit may have a temperature in a specific range when the coil unit receives wireless power from the outside, thereby improving the heat reduction effect.

3A to 3D, when the wireless power having a frequency of 85 kHz and an output of 6.6 kW is transmitted to the coil unit for 10 minutes, the lower surface of the first magnetic unit 300 facing the coil unit 200 When P1 and the upper surface of the second magnetic part 500 facing the shield part 400 is P2, the temperature T1 ₁₀ of the lower surface P1 of the first magnetic part 300 is the second _{The temperature T2 10} of the upper surface P2 of the magnetic part 500 may be 1°C or more lower than the temperature T2 10 .

_{Specifically, the temperature T1 10} of the lower surface P1 of the first magnetic part 300 _{is higher than the temperature T2 10} of the upper surface P2 of the second magnetic part 500 , for example, 1° C. to 5°C, such as 1°C to 4°C, such as 1°C to 3°C, such as 2°C to 3°C lower.

If only one of the first magnetic part and the second magnetic part is used, or the arrangement of the first magnetic part and the second magnetic part is different from the embodiment of the present invention, when wireless power is transmitted for 10 minutes, the T1 ₁₀ is It may be the same as or higher than _{T2 10 .} In addition, when the T1 ₁₀ is the _{same as or higher than the T2 10} , heat may increase during fast charging and high-power wireless charging. may cause restrictions or decrease charging efficiency.

According to an embodiment of the present invention, in the wireless charging device, in the SAE J2954 WPT2 Z2 class Standard TEST charging efficiency measurement condition, wireless power having a frequency of 85 kHz and an output of 6.6 kW to the coil unit is transmitted for 10 minutes or 60 minutes. At this time, the surface temperature of the magnetic part was measured. In the SAE J2954 WPT2 Z2 class Standard TEST, Society of Automotive Engineers (SAE) J2954 can produce performance, interoperability, and rated output for each capacity of a wireless power transmission system using magnetic induction for electric vehicles. It is a standard that includes various contents such as vertical and horizontal separation distance standards, communication methods between transmitting and receiving pads, operating frequency, EMI (Electromagnetic Interface)/EMC (Electromagnetic Compatibility), and stability. Since this standard provides not only the system performance but also the specification of the transmission/reception pad for each capacity band, most automobile manufacturers follow the configuration and size of the transmission/reception pad suggested in the standard when manufacturing the transmission/reception pad.

The surface temperature of the magnetic part is measured using a T/GUARD 405-SYSTEM manufactured by Qualitrol, respectively, as shown in FIGS. 3A to 3D , on the lower surface P1 of the first magnetic part and the upper surface P2 of the second magnetic part. In this case, the surface temperature is measured based on the center of the outer part, which is a position corresponding to the coil part.

According to an embodiment of the present invention, the T1 ₁₀ may be 55 °C to 75 °C, 57 °C to 73 °C, 58 °C to 70 °C, or 58 °C to 67 °C.

In addition, the T2 ₁₀ may be 56 °C to 76 °C, 58 °C to 74 °C, 59 °C to 71 °C, or 60 °C to 70 °C.

When wireless power having a frequency of 85 kHz and an output of 6.6 kW is transmitted to the coil unit for 10 minutes, the T1 ₁₀ is 1°C or more lower than the T2 _{10 , and the T1 10} and T2 ₁₀ are each in the above range. If satisfied, charging efficiency and heat reduction characteristics can be maximized.

On the other hand, when only one of the first magnetic part and the second magnetic part is used, or the arrangement of the first magnetic part and the second magnetic part is out of the embodiment of the present invention, when wireless power is transmitted for 10 minutes, the T1 ₁₀ and T2 ₁₀ may be out of the above range, respectively. As such, when the T1 ₁₀ and the T2 ₁₀ are out of the scope of the present invention, respectively, heat generation may increase during fast charging and high-power wireless charging. For safety reasons, usability may be restricted or charging efficiency may be reduced.

In addition, according to the embodiment of the present invention, when the wireless power is transmitted for 60 minutes, the temperature (T1 ₆₀ ) of the lower surface of the first magnetic part and the temperature (T2 ₆₀ ) of the upper surface of the second magnetic part are 100 ° C. to 180°C.

Specifically, when transmitted for 60 minutes under the above conditions, the temperature (T1 ₆₀ ) of P1 is 100°C to 180°C, 120°C to 180°C, 130°C to 180°C, 130°C to 160°C, or 136°C to 150°C. °C.

In addition, when transmitted for 60 minutes under the above conditions, the temperature (T2 ₆₀ ) of P2 is 100°C to 180°C, 120°C to 180°C, 120°C to 170°C, 125°C to 165°C, or 130°C to 160°C. can be

When the first magnetic part and the second magnetic part have a temperature in a specific range under the above conditions, charging efficiency and heat reduction characteristics may be maximized.

If only one of the first magnetic part and the second magnetic part is applied or the arrangement of the first magnetic part and the second magnetic part deviate from the embodiment of the present invention, the T1 ₆₀ and the T2 ₆₀ also deviate from the scope of the present invention. can As such, when the T1 ₆₀ and the T2 ₆₀ are out of the scope of the present invention under the above conditions, high-temperature heat generation may occur to continuously increase the temperature, and deformation and damage of the device structure may occur.

The difference (absolute value) between the T1 ₆₀ and the T2 ₆₀ may be 1°C to 15°C, 1°C to 12°C, 2°C to 12°C, 3°C to 12°C, or 5°C to 12°C. If _{the difference between T2 60} and T1 ₆₀ is too large, the transfer of heat generated because magnetic flux is not properly distributed during wireless charging is not effective, and it is easily caused by an external shock that may be applied while driving the vehicle. may be damaged.

In addition, according to an embodiment of the present invention, as shown in FIG. 3B or 3D, when the first magnetic part has a three-dimensional structure and the second magnetic part is in contact with the shield part, when wireless power is transmitted for 60 minutes, the shield part and _{T2 60, which} is the upper surface temperature of the contacted second magnetic part, is 1°C to 10°C, 1°C to 9°C, 1°C to 8°C, 2°C to 8°C, 3°C to 7°C, 4°C to 7 compared to T1 ₆₀ ℃, can be further reduced by about 5 to 7 ℃. In this case, when the coil unit receives wireless power from the outside compared to the first magnetic unit, by disposing the second magnetic unit in contact with the shield unit in contact with the shield unit, the magnetic flux density and heat emission are effectively distributed to increase the wireless charging efficiency. , it is possible to efficiently improve heat dissipation characteristics by dissipating heat generated from the second magnetic unit through the shield unit. Accordingly, when wireless power is transmitted for 60 minutes, the _{temperature of T2 60} may be further reduced compared to T1 _{60 .}

In addition, _{from T1 10} to T1 ₆₀ and T2 ₁₀ to T2 ₆₀ , respectively, 50° C. to 100° C. may be further increased. Specifically, the _{temperature from T1 10} to T1 ₆₀ may be further increased to 50° C. to 90° C., 50° C. to 85° C., or 50° C. to 80° C., and from T2 ₁₀ to T2 ₆₀ from 50° C. to 100 °C, from 50 °C to 90 °C, from 50 °C to 80 °C, or from 50 °C to 70 °C.

If the T1 ₁₀ to T1 ₆₀ and T2 ₁₀ to T2 ₆₀ each further increases by more than 100° C., heat generation may increase during fast charging and high-power wireless charging. In this case, usability is restricted for safety reasons. can cause

In addition, in the wireless charging device according to an embodiment of the present invention, as shown in FIG. 3b or 3d, in the case of a wireless charging device in which the first magnetic part has a three-dimensional structure, and the second magnetic part contacts the shield part, as shown in FIG. 3a or 3c , It is possible to increase the heat dissipation effect and charging efficiency compared to a wireless charging device in which the first magnetic part has a planar structure or the second magnetic part does not contact the shield part. Specifically, as shown in FIG. 3b or 3d, in the case of a wireless charging device in which the first magnetic part has a three-dimensional structure and the second magnetic part is in contact with the shield part, the T1 _{60 in T1 10} , and/or the T2 _{60 in T2 10} may be further increased by 50 ° C to 80 ° C, respectively. On the other hand, as shown in FIG. 3A or 3C , in the case of a wireless charging device in which the first magnetic part has a planar structure or the second magnetic part does not contact the shield part, T1 ₁₀ to T1 ₆₀ , and T2 ₁₀ to T2 ₆₀ , respectively It may further increase above 80°C and up to 100°C.

Meanwhile, among the hybrid magnetic parts, the second magnetic part disposed close to the shield part may have a thinner thickness than the first magnetic part and may have a higher permeability at 79 kHz to 90 kHz. As described above, the wireless charging device designed by optimizing the thickness ratio and permeability of the first magnetic part and the second magnetic part can maximize charging efficiency and heat reduction characteristics especially at high power.

A total thickness of the first magnetic part and the second magnetic part may be 2.1 mm to 10 mm, 3.0 mm to 9 mm, or 4.0 mm to 8 mm. When the total thickness of the first magnetic part and the second magnetic part is too thick, the weight of the magnetic part may increase, and thus there may be restrictions on processes or use.

Thermal conductivity of the second magnetic portion compared to the first magnetic portion is 0.1 W/m·K to 6 W/m·K, 0.5 W/m·K to 5 W/m·K, or 1 W/m·K to 4 W/m·K can be higher. By disposing the second magnetic part, which has higher thermal conductivity than the first magnetic part, adjacent to the shield part, the heat generated during wireless charging is effectively dispersed through the distribution of magnetic flux, and the durability against external shock or distortion can be improved. have.

In addition, by adjusting the amount (volume) used for each magnetic part in consideration of the magnetic properties and physical properties of the two or more types of magnetic parts, it is possible to improve the impact resistance and reduce the manufacturing cost without impairing charging efficiency. For example, the first magnetic part may have a volume 2 to 9.5 times larger than that of the second magnetic part.

Hereinafter, the first magnetic part and the second magnetic part will be described in detail.

first magnetic part

Type of first magnetic part

The magnetic part according to an embodiment of the present invention may include a first magnetic part, and the first magnetic part may include a polymer-type magnetic block (PMB) including a binder resin and magnetic powder dispersed in the binder resin. The first magnetic part includes a polymer-type magnetic block and magnetic powders are combined with each other by a binder resin, so that overall there are fewer defects in a large area, less damage by impact, excellent impact resistance, weight reduction, etc. can

The magnetic powder may be an oxide-based magnetic powder, a metal-based magnetic powder, or a mixed powder thereof. For example, the oxide-based magnetic powder may be a ferrite-based powder, specifically, a Ni-Zn-based, Mg-Zn-based, or Mn-Zn-based ferrite powder. In addition, the metal-based magnetic powder may be a Fe-Si-Al alloy magnetic powder or a Ni-Fe alloy magnetic powder, and more specifically, may be a sandust powder or a permalloy powder.

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

[Formula 1]

Fe _1-abc Si _a X _b Y _c

wherein 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 part may include the magnetic powder in an amount of 10 wt% or more, 50 wt% or more, 70 wt% or more, or 85 wt% or more.

For example, the first magnetic portion contains 10 wt% to 99 wt%, 10 wt% to 95 wt%, 50 wt% to 95 wt%, 50 wt% to 92 wt%, 70 wt% to 95 wt% of the magnetic powder. weight %, 80% to 95% by weight, or 80% to 90% by weight.

As the binder resin, polyimide resin, polyamide resin, polycarbonate resin, acrylonitrile-butadiene-styrene (ABS) resin, polypropylene resin, polyethylene resin, polystyrene resin, polyphenylsulfide (PSS) resin, polyether ether ketone (PEEK) resin, silicone resin, acrylic resin, polyurethane resin, polyester resin, isocyanate resin, epoxy resin and the like may be exemplified, but is not limited thereto.

For example, the binder resin may be a curable resin. Specifically, the binder resin may be a photocurable resin and/or a thermosetting resin, and in particular, may be a resin capable of exhibiting adhesiveness by curing. More specifically, the binder resin may include at least one functional group or site that can be cured by heat, such as a glycidyl group, an isocyanate group, a hydroxyl group, a carboxyl group, or an amide group; or at least one functional group or site 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 resin can be used. Such a functional group or moiety may be, for example, an isocyanate group (-NCO), a hydroxyl group (-OH), or a carboxyl group (-COOH).

The first magnetic part 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, based on the weight of the first magnetic part, as the binder resin, 6 wt% to 12 wt% of a polyurethane-based resin, 0.5 wt% to 2 wt% of an isocyanate-based curing agent, and 0.3 wt% to 1.5 wt% of an epoxy-based resin.

Structural features of the first magnetic part

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

The first magnetic part may be disposed to be spaced apart from the coil part by a predetermined interval. For example, the separation distance between the first magnetic part and the coil part may be 0.2 mm or more, 0.5 mm or more, 0.2 mm to 3 mm, or 0.5 mm to 2 mm.

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

According to an embodiment of the present invention, the first magnetic part may have a three-dimensional structure, and in this case, charging efficiency and heat dissipation characteristics may be improved.

1B and 3B, the first magnetic unit 300 includes an outer portion 310 corresponding to a portion where the coil unit 200 is disposed; and a central portion 320 surrounded by the outer portion 310 , wherein a thickness of the outer portion 310 may be greater than a thickness of the central portion 320 . In this case, in the first magnetic part, the outer part and the central part may be integrally formed with each other.

As described above, by increasing the thickness of the magnetic part near the coil where electromagnetic energy is concentrated during wireless charging and lowering the thickness of the central magnetic part having a relatively low electromagnetic energy density because there is no coil, the electromagnetic waves concentrated around the coil are effectively focused and charged. In addition to improving efficiency, it is possible to firmly maintain a distance between the coil and the shield unit without a separate spacer, thereby reducing material and processing costs due to the use of spacers and the like.

In the first magnetic part, the outer part may have a thickness that is 1.5 times or more thicker than that of the central part. When the thickness ratio is above, it is possible to more effectively focus the magnetic field concentrated around the coil to improve charging efficiency, and it is also advantageous for heat generation and weight reduction. Specifically, in the first magnetic part, the thickness ratio of the outer part/central part 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 outer portion of the first magnetic part 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 central portion of the first magnetic part 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 outer portion of the first magnetic portion may have a thickness of 5 mm to 11 mm, and the central portion may have a thickness of 0 mm to 5 mm.

When the thickness of the central part 320 of the first magnetic part 300 is 0, the first magnetic part 300 may have an empty shape in the central part 320 (eg, a donut shape). In this case, the charging efficiency can be effectively improved even with a smaller area of the first magnetic part.

Also, according to an exemplary embodiment, the first magnetic part may have a planar structure (see FIGS. 3A and 3C ) rather than a three-dimensional structure. That is, in the first magnetic portion, the outer portion and the central portion may have the same thickness.

Meanwhile, the first magnetic part 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. Also, the first magnetic part may have an area ^{of 10,000 cm 2 or less.}

The large-area first magnetic part may be configured by combining a plurality of unit magnetic parts, and in this case, an area of the unit magnetic part may be 60 cm ² or more, 90 cm ² , or 95 cm ² to 900 cm ² .

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

The first magnetic part may be a magnetic block manufactured by a method such as molding through a mold. For example, the first magnetic part may be molded into a three-dimensional structure through a mold. Such a magnetic sheet may be molded 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.

Specifically, the molding may be performed by injecting the raw material of the magnetic part into the mold by injection molding. More specifically, the magnetic part is manufactured by mixing magnetic powder and a polymer resin composition to obtain a raw material composition, and then injecting the raw material composition 701 into the mold 703 by an injection molding machine 702 as shown in FIG. 4 . can be At this time, by designing the internal shape of the mold 703 as a three-dimensional structure, the three-dimensional structure of the magnetic part can be easily implemented. Such a process may be difficult when an existing sintered ferrite sheet is used as a magnetic part.

Alternatively, the first magnetic part may be a laminate of magnetic sheets, and for example, 20 or more magnetic sheets, or 50 or more magnetic sheets may be laminated.

Specifically, the magnetic sheet stack may be one in which one or more additional magnetic sheets are further stacked only at the center of the first magnetic part. In this case, the thickness of each 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 to form a slurry, then forming and curing the magnetic sheet into a sheet shape.

Magnetic properties of the first magnetic part

The first magnetic part may have a magnetic characteristic of a certain level in the vicinity of the wireless charging standard frequency of the electric vehicle.

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

The magnetic permeability in the frequency band of 79 kHz to 90 kHz of the first magnetic part may vary depending on the material, and may be in the range of 5 to 150,000, and may be in the range of 5 to 300, 500 to 3,500, or 10,000 to 150,000 depending on the specific material. have. In addition, the investment loss in the frequency band of 79 kHz to 90 kHz of the first magnetic part may vary depending on the material, and may be 0 to 50,000 in a wide range, 0 to 1,000, 1 to 100, 100 to 1,000, depending on the specific material, or 5,000 to 50,000.

As a specific example, when the first magnetic part is a polymer-type magnetic block including a magnetic powder and a binder resin, the magnetic permeability is 5 to 500, 5 to 130, in a frequency band of 79 kHz to 90 kHz, for example, 85 kHz. 15 to 80, or 10 to 50, and the investment loss may be 0 to 50, 0 to 20, 0 to 15, or 0 to 5.

Physical properties of the first magnetic part

The first magnetic part may be elongated at a certain rate. For example, the elongation of the first magnetic part may be 0.5% or more. The elongation characteristic is difficult to obtain in a ceramic magnetic part to which a polymer is not applied, and damage can be reduced even when a large-area magnetic part is distorted due to an impact. Specifically, the elongation of the first magnetic part 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, properties such as inductance of the magnetic part may be deteriorated, so that the elongation is preferably 10% or less.

The first magnetic part has a small rate of change in characteristics before and after impact, and is significantly superior to that of a general ferrite magnetic sheet.

In the present specification, the characteristic change rate (%) before and after the impact of a certain characteristic may be calculated by the following formula.

Characteristic change rate (%) = | Property Values Before Impact - Property Values After Impact | / property value before impact x 100

For example, the inductance change rate before and after the impact applied by free-falling the first magnetic part from a height of 1 m may be less than 5%, or less than 3%. 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 inductance change rate before and after the impact is relatively small, so the stability of the magnetic part may be further improved.

In addition, the first magnetic part may be free-falling from a height of 1 m and the change rate of the quality factor (Q factor) before and after the applied impact may be 0% to 5%, 0.001% to 4%, or 0.01% to 2.5%. When within the above range, the change in characteristics before and after the impact is small, so the stability and impact resistance of the magnetic part may be further improved.

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

In addition, the charge efficiency change rate before and after the impact applied by free-falling from a height of 1 m to the first magnetic part may be 0% to 6.8%, 0.001% to 5.8%, or 0.01% to 3.4%. When it is within the above range, the properties of the large-area magnetic part may be more stably maintained even if impact or distortion occurs repeatedly.

second magnetic part

Type of second magnetic part

The wireless charging device according to an exemplary embodiment of the present invention includes a second magnetic unit having a different heating value from the first magnetic unit.

The second magnetic part may be a ferritic magnetic part, and specifically, may include an oxide-based magnetic part, a metal-based magnetic part, or a composite material thereof.

According to an embodiment of the present invention, by using a material having a strong magnetic focusing force as the second magnetic portion, the disadvantage of the first magnetic portion, which may cause a decrease in charging efficiency due to a weak magnetic focusing force (inductance), can be compensated. have.

If only the first magnetic part is used without the second magnetic part, there may be effects such as impact resistance and weight reduction, but the magnetic focusing force (inductance) may be weak, and thus charging efficiency may be deteriorated. On the other hand, although the second magnetic part has a strong magnetic focusing force, it is difficult to process a plate enlargement, and there may be restrictions in manufacturing and processing in the form of a thick film for automobiles. Accordingly, the performance of the wireless charging device can be effectively improved by using the second magnetic part having a strong magnetic focusing force together with the first magnetic part having high impact resistance and a weight reduction effect.

The oxide-based magnetic part may be a ferrite-based material, and a specific chemical formula may be expressed as MOFe ₂ O ₃ (where M is one or more divalent metal elements such as Mn, Zn, Cu, Ni). The ferritic material is advantageous in terms of magnetic properties such as magnetic permeability that it is a sintered body. The ferritic material may be manufactured in the form of a sheet or block by mixing raw materials, calcining, pulverizing, mixing this with a binder resin, molding, and firing.

More specifically, the oxide-based magnetic part may be a Ni-Zn-based, Mg-Zn-based, or Mn-Zn-based ferrite. In particular, the Mn-Zn-based ferrite has a temperature range of room temperature to 100° C. or higher at a frequency of 79 kHz to 90 kHz. It can exhibit high permeability, low investment loss, and high saturation magnetic flux density.

The Mn-Zn-based ferrite is iron oxide Fe ₂ O ₃ 66 mol% to 70 mol%, ZnO 10 mol% to 20 mol%, MnO 8 mol% to 24 mol%, NiO 0.4 mol% to 2 mol% as a main component. and SiO ₂ , CaO, Nb ₂ O ₅ , ZrO ₂ , SnO and the like as other subcomponents. The Mn-Zn-based ferrite is pulverized by mixing the main component in a predetermined molar ratio, calcining in the air at a temperature of 800 ° C. to 1100 ° C. for 1 hour to 3 hours, and then adding the sub-components, and thus a binder such as polyvinyl alcohol (PVA) After mixing an appropriate amount of the resin and press-molding using a press, the temperature is raised to 1200° C. to 1300° C. and calcined for 2 hours or more, thereby producing a sheet or block form. Then, it is cut to a required size through processing using a wire saw or a water jet, if necessary.

In addition, the metal-based magnetic part may be a Fe-Si-Al alloy magnetic part or a Ni-Fe alloy magnetic part, and more specifically, may be sandust or permalloy.

In addition, the second magnetic portion may include a nanocrystalline magnetic portion, for example, a Fe-based nanocrystalline magnetic portion, specifically, a Fe-Si-Al-based nanocrystalline magnetic portion, Fe-Si-Cr-based magnetic portion It may include a nanocrystalline magnetic part, or a Fe-Si-B-Cu-Nb based nanocrystalline magnetic part. When the nanocrystalline magnetic part is applied as the second magnetic part, the higher the distance from the coil part, the lower the resistance (Rs) even if the inductance (Ls) of the coil part is lowered, so that the quality factor of the coil part (Q factor: Ls/Rs) may be increased to improve charging efficiency and reduce heat generation.

The second magnetic part may be made of a magnetic material different from that of the first magnetic part. As a specific example, the first magnetic part includes a Fe-Si-Al-based alloy magnetic part, and the second magnetic part includes Mn-Zn-based ferrite, Fe-Si-Al-based nanocrystalline magnetic powder, and Fe-Si-Cr-based alloy. It may include at least one selected from the group consisting of a magnetic nanocrystalline powder, and a Fe-Si-B-Cu-Nb-based nanocrystalline magnetic powder. The combination of the first magnetic part and the second magnetic part is advantageous in that the second magnetic part has a higher magnetic permeability at 79 kHz to 90 kHz than the first magnetic part.

Structural features of the second magnetic part

The second magnetic part may have a sheet shape or a block shape.

In addition, the thickness of the second magnetic part may be 0.5 mm to 5 mm, specifically, 0.5 mm to 3 mm, 0.5 mm to 2 mm, or 1 mm to 2 mm.

The second magnetic portion may have the same area as the first magnetic portion or may have a different area from that of the first magnetic portion.

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

Alternatively, the second magnetic part may have a smaller area than the first magnetic part. For example, when the second magnetic portion is disposed only on the outer portion of the first magnetic portion, the second magnetic portion may have an area corresponding to the area of the outer portion. Also, according to this, the second magnetic part may be disposed at a position corresponding to the coil part, and may have an area corresponding to the area of the coil part. In this case, the second magnetic part can effectively improve charging efficiency and heat dissipation characteristics even with a small area.

Magnetic properties of the second magnetic part

The second magnetic part may have a magnetic characteristic in a specific range near the wireless charging standard frequency of the electric vehicle.

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

As a specific example, when the second magnetic part is a ferritic material, the magnetic permeability in a frequency band of 79 kHz to 90 kHz, for example, a frequency band of 85 kHz, may be 1,000 to 20,000, 1,000 to 5,000, or 2,000 to 4,000, The loss can be 0 to 1,000, 0 to 500, 0 to 100, or 0 to 50.

According to the embodiment, the second magnetic part has a higher magnetic permeability at 79 kHz to 90 kHz than the first magnetic part. For example, the difference in permeability between the second magnetic part and the first magnetic part at 79 kHz to 90 kHz may be 100 or more, 500 or more, or 1,000 or more, and specifically 100 to 5,000, 500 to 4,000, or 1,000 to 4,000.

Specifically, the first magnetic part may have a magnetic permeability of 5 to 300 in 79 kHz to 90 kHz, and the second magnetic part may have a magnetic permeability of 1,000 to 5,000 in 79 kHz to 90 kHz.

During wireless charging, the magnetic flux density is higher as it approaches the coil part, but when the magnetic part is around the coil part, the magnetic flux is concentrated in the magnetic part. do. Accordingly, when the second magnetic portion having a higher magnetic permeability than the first magnetic portion is properly disposed, magnetic flux can be effectively distributed.

arrangement of the second magnetic part

According to the embodiment of the present invention, since the second magnetic part has a larger amount of heat when the coil part receives wireless power from the outside compared to the first magnetic part, it is advantageous to be disposed close to the shield part. For example, when a ferritic sintered body is included as the second magnetic part, the ferritic sintered body generates a lot of heat, but may well dissipate heat. Accordingly, by disposing the second magnetic portion having such a heat amount close to the shield portion, heat reduction characteristics may be further improved. If the first magnetic part having a small amount of heat including the polymer-type magnetic part is disposed close to the shield part, the polymer component included in the polymer-type magnetic part accumulates heat, so that the temperature continuously rises over time. It may adversely affect the heat reduction characteristics.

Specifically, referring back to FIGS. 3A to 3D , the second magnetic part 500 may be disposed between the shield part 400 and the first magnetic part 300 . As described above, by disposing the second magnetic part having a larger amount of heat compared to the first magnetic part close to the shield part, it is possible to effectively disperse the high magnetic flux density around the coil part, so that when the first magnetic part is used alone Compared to that, it is possible to not only increase the charging efficiency, but also effectively dissipate the heat concentrated in the vicinity of the coil part of the first magnetic part.

At this time, as shown in FIGS. 3B and 3D , at least a portion of the second magnetic part may contact the shield part. Accordingly, heat generated from the second magnetic part may be effectively discharged through the shield part. For example, when the second magnetic part is in the form of a sheet, an entire surface of the second magnetic part may contact the shield part. Specifically, the second magnetic part may be attached to one surface of the shield part facing the first magnetic part. The second magnetic part may be attached to one surface of the shield part with a thermally conductive adhesive, thereby further enhancing the heat dissipation effect. The thermally conductive adhesive may include a thermally conductive material such as a metal-based, carbon-based, or ceramic-based adhesive, for example, an adhesive resin in which thermally conductive particles are dispersed.

In addition, as shown in FIG. 3A , the second magnetic part 500 is located in both the outer part 310 corresponding to the coil part 200 and the central part 320 surrounded by the outer part 310 . can be deployed

Also, as shown in FIGS. 3B to 3D , the second magnetic part 500 may be disposed only in the outer part 310 corresponding to the coil part 200 . Accordingly, a high magnetic flux density around the coil part can be effectively dispersed, and thus charging efficiency can be increased compared to the case of using the first magnetic part alone.

Alternatively, the second magnetic part may be disposed over at least a portion of the outer part and the central part.

The second magnetic part may be disposed to be coupled to or separated from the first magnetic part.

Meanwhile, the second magnetic part may also contact the first magnetic part. For example, referring to FIGS. 3B to 3D , the second magnetic part 500 may be attached to an outer portion of the first magnetic part 300 .

Alternatively, the second magnetic part may be disposed to be spaced apart from the first magnetic part by a predetermined distance. For example, the separation distance between the first magnetic part and the second magnetic part 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

In addition, referring back to FIG. 3D , the first magnetic part 300 may have a groove on the surface facing the shield part 400 , and the second magnetic part 500 may be inserted into the groove to be disposed. have.

In this case, since the first magnetic part may serve as a housing of the second magnetic part, a separate adhesive or structure for fixing the second magnetic part may not be required. In particular, since the first magnetic part can be molded into a three-dimensional structure through a mold using a polymer-type magnetic part using magnetic powder and a binder resin, a groove for inserting the second magnetic part can be easily formed.

In this case, at least a portion of the first magnetic part and the second magnetic part may contact the shield part. Accordingly, heat generated in the first magnetic part and/or the second magnetic part may be effectively discharged through the shield part.

The depth of the groove formed in the first magnetic part may be the same as or different from the thickness (height) of the second magnetic part. When the depth of the groove and the thickness of the second magnetic part are the same, the first magnetic part and the second magnetic part may contact the shield part at the same time. Alternatively, when the depth of the groove is smaller than the thickness of the second magnetic part, only the second magnetic part may contact the shield part. Conversely, when the depth of the groove is greater than the thickness of the second magnetic part, only the first magnetic part may contact the shield part.

Also, referring to FIGS. 3A and 3C , the second magnetic part 500 may be disposed to be spaced apart from the shield part 400 by a predetermined distance. In addition, an empty space or a spacer part 700 may be further included between the second magnetic part 500 and the shield part 400 . The material and structure of the spacer part 700 may adopt a material and structure of a typical housing used in a wireless charging device.

shield part

The wireless charging device 10 according to the embodiment may further include a shield unit 400 serving to increase wireless charging efficiency through electromagnetic wave shielding.

The shield part is disposed on one surface of the coil.

The shield portion includes a metal plate, and the material thereof may be aluminum, and other metal or alloy materials 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.

Also, the area of the shield part may be 200 cm ² or more, 400 cm ² or more, or 600 cm ² or more.

housing

The wireless charging device 10 according to the embodiment may further include a housing 600 accommodating the coil unit 200 , the first magnetic unit 300 , and the second magnetic unit 500 .

In addition, the housing 600 is configured such that components such as the coil unit 200, the shield unit 400, the first magnetic unit 300 and the second magnetic unit 500 are properly arranged and assembled. do. The shape (structure) of the housing may be arbitrarily set according to the components included therein or according to the environment. The material and structure of the housing may adopt a material and structure of a typical housing used in a wireless charging device.

support

The wireless charging device 10 according to the embodiment may further include a support part 100 for supporting the coil part 200 . The material and structure of the support part may adopt a material and structure of a conventional support part used in a wireless charging device. The support part may have a flat plate structure or a structure in which a groove is dug along a coil shape to fix the coil part.

On the other hand, the wireless charging device of the present invention can efficiently reduce heat generated when the coil unit receives wireless power from the outside when performing high-power wireless charging of 3 kW to 22 kW, 4 kW to 20 kW, or 5 kW to 18 kW, and charging Since efficiency can be improved, it can be usefully used for high-power wireless charging.

In particular, the wireless charging device can further improve charging efficiency and heat reduction characteristics by applying a three-dimensional structure to the magnetic part.

The charging efficiency of the wireless charging device according to an embodiment of the present invention may be 85% or more, 88% or more, 89% or more, 90% or more, or 91% or more.

Accordingly, the wireless charging device may be usefully used in an electric vehicle requiring large-capacity power transmission between a transmitter and a receiver.

[transportation]

5 is a moving means to which a wireless charging device is applied, specifically, an electric vehicle, and may be wirelessly charged in a parking area equipped with a wireless charging system for an electric vehicle by providing a wireless charging device at the lower part.

Referring to FIG. 5 , the electric vehicle 1 according to an embodiment includes the wireless charging device according to the embodiment as a receiver 720 .

The wireless charging device may serve as a receiver of wireless charging of the electric vehicle 1 and receive power from a transmitter 730 of wireless charging.

As such, the moving means includes a wireless charging device, and the wireless charging device includes a coil unit; a first magnetic part disposed on the coil part; a second magnetic part disposed on the first magnetic part; and a shield portion disposed on the second magnetic portion, wherein when the coil portion receives wireless power from the outside, more heat is generated in the second magnetic portion than in the first magnetic portion, included in the moving means The configuration and characteristics of each component of the wireless charging device are as described above.

The moving means 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 driving system of the electric vehicle. The battery may be charged by power transmitted from the wireless charging device or other additional wired charging devices.

In addition, the moving means may further include a signal transmitter for transmitting information about the charging to the transmitter of the wireless charging system. The information about such charging may be charging efficiency such as charging speed, charging state, and the like.

Example

Example 1: Preparation of a wireless charging device

Step 1: Preparation of the first magnetic part (PMB magnetic part) (three-dimensional structure)

42.8 parts by weight of magnetic powder, 15.4 parts by weight of polyurethane-based resin dispersion (25% by weight of polyurethane-based resin, 75% by weight of 2-butanone), 1.0 parts by weight of isocyanate-based curing agent dispersion (62% by weight of isocyanate-based curing agent, n-butyl acetate 25 weight %, 2-butanone 13% by weight), 0.4 parts by weight of an epoxy-based resin dispersion (epoxy-based resin 70% by weight, n-butyl acetate 3% by weight, 2-butanone 15% by weight, toluene 12% by weight), and 40.5 parts by weight of toluene was mixed in a planetary mixer at a speed of about 40 to 50 rpm for about 2 hours to prepare a magnetic powder slurry.

As shown in FIG. 4, the magnetic powder slurry is injected into a mold 703 by an injection molding machine 702 to form a three-dimensional structure (outer part corresponding to the coil part: 9 mm, a central part surrounded by the outer part) : 1 mm), and dried at a temperature of about 160° C. to obtain a first magnetic part having a three-dimensional structure.

Step 2: Fabrication of the hybrid magnetic part

A ferritic magnetic part (PC-95 ferrite magnetic sheet manufactured by TDK, a second magnetic part) having a thickness of 1 mm was placed on the outer part corresponding to the coil part of the first magnetic part manufactured in step 1, and then fixed by thermocompression bonding. A hybrid type magnetic part was obtained.

Step 3: Fabrication of the wireless charging device

A wireless charging device including a coil part including a conductive wire, the hybrid magnetic part, and a shield part was obtained by using the hybrid magnetic part of step 2. At this time, the ferritic magnetic part (second magnetic part) was disposed to face the shield part (see FIG. 3B ).

Example 2

Step 1: Preparation of the first magnetic part (PMB magnetic part) (planar structure)

In step 1 of Example 1, the magnetic powder slurry was coated on a carrier film by a comma coater, and dried at a temperature of about 110° C. to form a dry magnetic composite. The dried magnetic composite was compression-hardened at a temperature of about 170° C. and a pressure of about 9 Mpa for about 60 minutes by a hot press process to obtain a sheet-type magnetic composite. The magnetic powder content of the thus prepared magnetic composite was about 90%, and the thickness of one sheet was about 100 μm. For the sheet, 40 to 50 sheets were stacked to obtain a first magnetic part having a thickness of about 4 mm.

Step 2 and Step 3

A hybrid type magnetic part (thickness 5) fixed by thermocompression bonding after placing a 1 mm-thick ferritic magnetic part (PC-95 ferrite magnetic sheet manufactured by TDK, the second magnetic part) on the first magnetic part manufactured in step 1 above mm), and using this, a wireless charging device having the same structure as in FIG. 3a was obtained in the same manner as in Example 1 (see FIG. 3a).

Comparative Example 1

A wireless charging device was obtained in the same manner as in Example 2, except that only the first magnetic part (thickness 5 mm) obtained in step 1 of Example 2 was included.

Comparative Example 2

Example 2, except that the first magnetic part obtained in step 1 of Example 2 was not used, and only a ferritic magnetic part (PC-95 ferrite magnetic sheet manufactured by TDK, second magnetic part) (thickness 5 mm) was included. A wireless charging device was obtained by performing the same method as described above.

test example

(1) Measurement of surface temperature of magnetic part

The wireless charging device obtained in the above Examples and Comparative Examples was placed in a housing to obtain a wireless charging device.

In the SAE J2954 WPT2 Z2 class Standard TEST charging efficiency measurement condition for the wireless charging device obtained in the Examples and Comparative Examples, wireless power having a frequency of 85 kHz and an output of 6.6 kW in the coil unit was applied for 10 minutes, and for 60 minutes When transmitted, the surface temperatures of the first magnetic portion and the second magnetic portion were measured.

Specifically, the surface temperature of the magnetic part was determined using the T/GUARD 405-SYSTEM of Qualitrol, as shown in FIGS. 3A and 3B , the lower surface P1 of the first magnetic part and the upper surface of the second magnetic part in Examples 1 and 2 (P2) was measured, respectively. In addition, in Comparative Examples 1 and 2, the temperature was measured by using the lower and upper surfaces of the first magnetic part or the second magnetic part as P1 and P2, respectively. In this case, the surface temperature was measured based on the center of the outer part, which is a position corresponding to the coil part.

(2) Charging Efficiency Measurement

Charging efficiency was measured by SAE J2954 WPT2 Z2 Class standard TEST method. Specifically, SAE J2954 WPT2 Z2 Class standard TEST standard coil part and frame are applied and magnetic part, spacer, and aluminum plate are stacked to manufacture receiving pad (35 cm X 35 cm) and transmitting pad (75 cm X 60 cm) Therefore, the charging efficiency was evaluated under the same conditions with an output power of 6.6 kW at a frequency of 85 kHz.

The measurement results are summarized in Table 1 below.

division Example 1 Example 2 Comparative Example 1 Comparative Example 2 10 minutes T1 ₁₀ (℃) 58 67 80 50 T2 ₁₀ (℃) 60 70 80 50 60 minutes T1 ₆₀ (℃) 136 150 190 90 T2 ₆₀ (℃) 130 160 200 90 Charging Efficiency (%) 90 90 87 91 Weight (kg) 3.5 3.5 3.4 4 T1 ₁₀ : When the wireless power is transmitted for 10 minutes, the temperature of the lower surface (P1) of the first magnetic part
T2 ₁₀ : When the wireless power is transmitted for 10 minutes, the temperature of the upper surface (P2) of the second magnetic part
T1 ₆₀ : When the wireless power is transmitted for 60 minutes, the temperature of the lower surface (P1) of the first magnetic part
T2 ₆₀ : When the wireless power is transmitted for 60 minutes, the temperature of the upper surface (P2) of the second magnetic part

As shown in Table 1 above, as the magnetic part, two types of hybrid magnetic parts with different calorific values are used, and compared to the first magnetic part among the magnetic parts, the second having a larger heating value when the coil part receives wireless power from the outside. The wireless charging devices of Examples 1 and 2 in which the magnetic part is disposed close to the shield part are compared to Comparative Examples 1 and 2 using only the first magnetic part or the second magnetic part, by effectively distributing the magnetic flux density and heat emission to increase the wireless charging efficiency. It was confirmed that it can be improved.

Specifically, when wireless power having a frequency of 85 kHz and an output of 6.6 kW is transmitted to the coil unit for 10 minutes, in the case of the wireless charging devices of Examples 1 and 2, the temperature of the lower surface P1 of the first magnetic unit (T1 _{10 ) was lower than the temperature (T2 10} ) of the upper surface (P2) of the second magnetic part by about 1 ℃ to 3 ℃, the wireless charging devices of Comparative Examples 1 and 2 when the wireless power is transmitted for 10 minutes , P1 temperature (T1 ₁₀ ) and P2 temperature (T2 ₁₀ ) showed the same temperature.

On the other hand, when the wireless power was transmitted for 60 minutes, in the case of the wireless charging apparatus of Examples 1 and 2, the temperature of P1 (T1 ₆₀ ) and the temperature of P2 (T2 ₆₀ ) were within 100°C to 180°C. In addition, _{from T1 10} to T1 ₆₀ and from T2 ₁₀ to T2 ₆₀ , respectively, 50° C. to 100° C. was further increased, and _{the difference between T2 60} and T1 ₆₀ was within 1° C. to 15° C.

In addition, comparing the heat dissipation characteristics according to the structures of the wireless charging devices of Examples 1 and 2, the wireless charging device of Example 1 has a three-dimensional structure, and the second magnetic part is in contact with the shield part, so that the wireless power is _{When transmitted for 60 minutes, T2 60, which} is the upper surface temperature of the second magnetic part in contact with the shield part, was further reduced by about 6 ° C compared to T1 ₆₀ , and it can be seen that the temperature is significantly reduced compared to the wireless charging device of Example 2 there was. For this reason, it can be seen that the heat reduction effect is remarkably improved compared to the wireless charging device of Example 2 in which the second magnetic part does not contact the shield part by contacting the shield part with the second magnetic part.

On the other hand, in Comparative Example 1, T1 ₁₀ and T2 ₁₀ , and T1 ₆₀ and T2 ₆₀ were significantly higher than Examples 1 and 2, and it was confirmed that heat generation increased. In addition, in the case of Comparative Example 2, the temperatures are lower than in Examples 1 and 2, but the impact resistance may be lowered by using only the ferrite sheet, and the problem of weight increase and cost increase may occur, and the attachment and assembly of the magnetic part may be performed. It is not preferable because a separate frame may be required for this purpose.

Therefore, it was confirmed that Examples 1 and 2 can improve charging efficiency and heat reduction characteristics in an efficient way.

1: means of transportation (electric vehicle)
10, 10a, 10b, 10c, 10d: wireless charging device
100: support part 200: coil part
300: first magnetic part 310: outer part
320: central 400: second magnetic part
500: second magnetic part 600: housing
700: spacer part
701: raw material composition 702: injection molding machine
703 : mold
720: receiver 730: transmitter
P1: lower surface of the first magnetic part
P2: upper surface of the second magnetic part
A-A': incision line
B-B': incision line

Claims (10)

coil unit;
a first magnetic part disposed on the coil part;
a second magnetic part disposed on the first magnetic part; and
a shield portion disposed on the second magnetic portion;
When the coil unit receives wireless power from the outside, more heat is generated in the second magnetic unit than in the first magnetic unit,
wireless charging device.
The method of claim 1,
When the wireless power having a frequency of 85 kHz and an output of 6.6 kW is transmitted to the coil unit for 10 minutes, the temperature (T1 ₁₀ ) of the lower surface of the first magnetic unit is higher than _{the temperature (T2 10 ) of the upper surface of the second magnetic unit} lower than 1℃,
wireless charging device.
3. The method of claim 2,
When the wireless power is transmitted for 60 minutes, the _{difference between the temperature (T1 60} ) of the lower surface of the first magnetic part and the temperature (T2 ₆₀ ) of the upper surface of the second magnetic part is 1° C. to 15° C.,
wireless charging device.
4. The method of claim 3,
In the T1 ₁₀ , the T1 ₆₀ , and the T2 ₁₀ to the T2 ₆₀ , respectively 50 ℃ to 100 ℃ more increased,
wireless charging device.
The method of claim 1,
The first magnetic part comprises a binder resin and magnetic powder dispersed in the binder resin,
The second magnetic part comprises a ferritic sintered body,
wireless charging device.
The method of claim 1,
The second magnetic part has a thermal conductivity of 0.1 W/m·K to 6 W/m·K higher than that of the first magnetic part,
wireless charging device.
The method of claim 1,
The first magnetic part has an investment loss of 0 to 50 and a magnetic permeability of 5 to 500 at 79 kHz to 90 kHz,
The second magnetic part has an investment loss of 0 to 1,000 and a magnetic permeability of 1,000 to 20,000 at 79 kHz to 90 kHz,
wireless charging device.
The method of claim 1,
The first magnetic part
an outer portion corresponding to the portion where the coil portion is disposed; and
Including a central portion surrounded by the outer portion,
The thickness of the outer portion is equal to or greater than the thickness of the central portion,
wireless charging device.
The method of claim 1,
At least a portion of the second magnetic part is in contact with the shield part,
wherein the first magnetic part has a groove on a surface facing the shield part, and the second magnetic part is inserted into the groove,
wireless charging device.
including a wireless charging device;
The wireless charging device is
coil unit;
a first magnetic part disposed on the coil part;
a second magnetic part disposed on the first magnetic part; and
a shield portion disposed on the second magnetic portion;
When the coil unit receives wireless power from the outside, more heat is generated in the second magnetic unit than in the first magnetic unit,
transportation.

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