KR102455473B1 - Wireless charging device and vehicle comprising same - Google Patents

Abstract

The wireless charging device according to an embodiment includes two types of magnetic parts, but by disposing a magnetic part having a higher magnetic permeability adjacent to the shield part, effectively dissipating heat generated during wireless charging through the distribution of magnetic flux, external shock or distortion, etc. durability can be improved. Therefore, the wireless charging device can be usefully used in a moving means such as an electric vehicle that requires large-capacity power transmission between a transmitter and a receiver.

Description

Wireless charging device and means of transportation including the same

The embodiment relates to a wireless charging device and a mobile means including 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.

Today, the information and communication field is developing at a very fast pace, and various technologies that comprehensively combine electricity, electronics, communication, and semiconductor are continuously being developed. In addition, as the trend toward mobileization of electronic devices increases, 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 an electronic device or the like is being actively conducted.

The wireless power transmission wirelessly transmits power through space using an electromagnetic field resonance structure such as magnetic coupling, capacitive coupling, or an antenna without physical contact between a transmitter that supplies power and a receiver that receives power. to be sent to The wireless power transmission is suitable for portable communication devices and electric vehicles that require a large-capacity battery, and since the contacts are 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 rapidly increased in recent years, interest in building charging infrastructure is increasing. Various charging methods such as electric vehicle charging using home chargers, battery replacement, rapid charging devices, and wireless charging devices have already appeared, and new charging business models have also begun to appear (refer to Korean Patent Publication 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 material is disposed adjacent to a coil to improve wireless charging efficiency, and a metal plate for shielding is disposed spaced apart from the magnetic material by a predetermined interval.

The wireless charging device generates heat due to the resistance of the coil and the magnetic loss of the magnetic material during the wireless charging operation. In particular, the magnetic material in the wireless charging device generates heat near the coil with high electromagnetic wave energy density, and the generated heat changes the magnetic properties of the magnetic material and causes an impedance mismatch between the transmitter and the receiver, reducing the charging efficiency and re- There was a problem that the fever worsened. However, since such a wireless charging device 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.

Korean Patent Publication No. 2011-0042403

The sintered ferrite sheet, which has been mainly used as a magnetic material in the existing wireless charging device, has excellent magnetic properties, but has high brittleness, lacks resistance to distortion, etc., and has a large weight. In addition, it is easily destroyed by thermal shock due to defects such as pores generated during the sintering process, which may cause secondary problems by generating fragments.

In order to compensate for the shortcomings of these sintered ferrite sheets, a polymer-type magnetic material with improved impact resistance by mixing magnetic powder with a binder resin can be applied. Therefore, it is difficult to downsize the device. In addition, the polymeric magnetic material does not generate a large amount of heat during wireless charging, but since the polymer component accumulates heat, the temperature is continuously increased over time when the magnetic flux is concentrated by being disposed around the coil.

In particular, when a sintered ferrite sheet and a polymer-type magnetic material are simply stacked and disposed without special consideration, the transfer of heat generated because magnetic flux is not properly distributed during wireless charging is not effective, and external impact that may be applied while driving the vehicle. It can be easily damaged by twisting or twisting.

As a result of research by the present inventors, by arranging such a heterogeneous magnetic material by adjusting the distance from the shield part according to the characteristics, the heat generated during wireless charging is effectively dispersed through the distribution of magnetic flux, and external shock or distortion is prevented. It has been found that durability can be improved.

Therefore, an object of the embodiment is to provide a wireless charging device having improved charging efficiency, heat dissipation characteristics and durability by using two different types of magnetic materials and arranging them in consideration of their characteristics, and a means of transport including the same.

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 having a higher magnetic permeability than the first magnetic part; and a shield portion disposed on the second magnetic portion, wherein the second magnetic portion is thermally connected to the shield portion.

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 having a higher magnetic permeability than the first magnetic part; and a shield portion disposed on the second magnetic portion, wherein the second magnetic portion is thermally connected to the shield portion.

According to the above embodiment, it is possible to effectively disperse heat generated during wireless charging through distribution of magnetic flux by disposing a magnetic part having a higher magnetic permeability and including two kinds of magnetic parts adjacent to the shield part. In addition, it is possible to improve the durability against external shocks or distortion by adjusting the materials of the two types of magnetic parts.

Specifically, the two types of magnetic parts have a difference in magnetic properties such as permeability, and when there is one or more magnetic parts, the magnetic flux density increases in the order of the magnitude of the magnetic permeability. You can distribute it in any direction you want. In addition, since heat is generated in a magnitude proportional to the amount of magnetic flux focused on the magnetic part and the investment loss during wireless charging, by arranging the two types of magnetic parts at appropriate intervals, heat can be effectively transferred to the shield part and released to the outside. , it is also possible to suppress damage caused by an external shock or distortion that may be applied while driving the vehicle.

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

1 is an exploded perspective view of a wireless charging device according to an embodiment.
2 and 3a are perspective and cross-sectional views of a wireless charging device according to an embodiment.
3b to 4b are cross-sectional views of a wireless charging device according to another embodiment.
5 shows an electric vehicle to which a wireless charging device is applied as a receiver.

In the description of embodiments below, one component is described as being formed above or below another component, one component is directly above or below another component, or indirectly through another component including all that are formed by

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

In the present specification, "including" any component means that other components may be further included, rather than excluding other components, unless otherwise stated.

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 this specification, unless otherwise specified, the expression "a" and "a" should be construed as meaning including the singular or the plural as interpreted in context.

In the conventional wireless charging device, as a magnetic material, a sintered ferrite sheet is mainly disposed between a coil and a metal plate, especially on one surface close to the coil, but the sintered ferrite sheet has a heavy specific gravity, and when the distance between the coil and the metal plate becomes close (eg 10 mm), there is a problem in that the efficiency rapidly decreases. Accordingly, a separate structure such as a spacer is required in order to maintain a distance between the coil and the metal plate and to stably fix the sintered ferrite sheet, thereby increasing the cost of the assembly process. In addition, heat is generated from the coil and the sintered ferrite sheet during charging. In particular, the heat generated from the sintered ferrite sheet is difficult to transmit and dissipate to air or spacers having low thermal conductivity properties. Accordingly, the magnetic properties of the sintered ferrite sheet having an elevated temperature are lowered, and the inductance value of the coil is changed accordingly, thereby lowering charging efficiency and causing more severe heat generation. To solve this problem, if the magnetic material is thick enough to fill the empty space between the coil and the metal plate, the heat dissipation characteristics can be improved, but the overall weight increases due to the magnetic material with a large specific gravity, which can be a problem in reducing the weight of the vehicle and manufacturing cost also increases significantly. Also, a method of filling all the empty space between the magnetic material and the metal plate with a heat dissipating material is being considered. If only a part of it is filled with a heat dissipation material, the heat dissipation performance will not be sufficient.

However, according to the following embodiments, it is possible to provide a wireless charging device with improved charging efficiency, heat dissipation characteristics, and durability by using two types of magnetic parts and disposing them in consideration of their characteristics.

[Wireless charging device]

1, 2 and 3A show an exploded perspective view, a perspective view, and a cross-sectional view of a wireless charging device according to an embodiment, respectively. In addition, Figures 3b to 4b shows a cross-sectional view of a wireless charging device according to another embodiment.

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; and a second magnetic part 500 disposed on the first magnetic part 300 and having a higher magnetic permeability than the first magnetic part 300 ; and a shield unit 400 disposed on the coil unit 200 , wherein the second magnetic unit 500 is thermally connected to the shield unit 400 .

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

support plate

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

coil part

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 one or more metals 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 a circular shape, 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 distance 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 dimension and specification range 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 first magnetic unit by a predetermined interval. For example, a distance between the coil unit and the first 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.

shield part

The shield part is disposed on the second magnetic part. In addition, the shield part may be disposed on the coil.

The shield unit suppresses electromagnetic interference (EMI) that may be generated by leakage of electromagnetic waves to the outside through electromagnetic shielding.

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

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

The material of the shield part may be, for example, a metal, and thus the shield part may be a metal plate, but is not particularly limited. As a specific example, the material of the shield part 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. In addition, the area of the shield part may be 200 cm ² or more, 400 cm ² or more, or 600 cm ² or more.

magnetic part

The wireless charging device according to the embodiment includes a first magnetic unit disposed on the coil unit; and a second magnetic part disposed on the first magnetic part and having a higher magnetic permeability than the first magnetic part.

Also, the first magnetic part and the second magnetic part may be disposed between the coil part and the shield part.

According to a specific example, the first magnetic part may include a binder resin and magnetic powder dispersed in the binder resin, and the second magnetic part may include a ferritic sintered body.

The first magnetic part and the second magnetic part may have magnetic characteristics in a predetermined range near a standard frequency for wireless charging of an 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.

In particular, the first magnetic part and the second magnetic part have differences in magnetic properties such as magnetic permeability and investment loss due to components constituting them. As a result, the heat generated during wireless charging can be effectively dispersed through the distribution of magnetic flux by combining the two types of magnetic parts.

For example, the second magnetic part may have a higher magnetic permeability than the first magnetic part at 85 kHz. In addition, the second magnetic part may have a higher investment loss than the first magnetic part at 85 kHz.

Specifically, the difference in permeability at 85 kHz between the second magnetic part and the first magnetic part 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 3,000. have. In addition, the second magnetic part may have a higher investment loss at 85 kHz than the first magnetic part. For example, the difference in investment loss at 85 kHz between the second magnetic part and the first magnetic part may be 10 or more, 50 or more, or 100 or more, specifically 10 to 300, 50 to 250, or 100 to 200 can be

Specifically, the first magnetic unit may have a magnetic permeability of 5 to 300 and an investment loss of 0 to 30 at 85 kHz, and the second magnetic unit may have a magnetic permeability of 1,000 to 5,000 and an investment loss of 0 to 300 at 85 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, the magnetic flux is concentrated in the magnetic part. . Accordingly, when the second magnetic portion having a higher magnetic permeability than the first magnetic portion is properly disposed, the magnetic flux can be effectively distributed.

In addition, since heat is generated in a magnitude proportional to the amount of magnetic flux focused on the magnetic part and the investment loss during wireless charging, the two types of magnetic parts have a difference in the amount of heat generated during wireless charging. For example, when wireless charging such as power transmission or reception, specifically, when wireless power from the outside is received by the coil unit, the amount of heat generated by the second magnetic unit may be greater than that of the first magnetic unit.

As described above, since the two types of magnetic parts have different magnetic properties and calorific value, depending on the method of arranging and combining them, the magnetic flux concentration during wireless charging is directed in the desired direction by using the tendency of the magnetic flux density to increase in the order of the magnetic permeability. It can be distributed, and heat can be effectively dissipated to the outside by using the tendency to increase the amount of heat in proportion to the amount of magnetic flux and the size of the investment loss.

3A to 4B , the first magnetic part 300 is disposed closer to the coil part 200 compared to the second magnetic part 500 , and the second magnetic part 500 is the first magnetic part 500 . It may be disposed closer to the shield unit 400 than the magnetic unit 300 . In this case, the second magnetic part may be thermally connected to the shield part. Accordingly, a large amount of heat generated from the second magnetic part may be easily discharged to the outside through the shield part.

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

Hereinafter, the composition and characteristics of each magnetic part will be described in detail.

first magnetic part

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

Accordingly, since the magnetic powders are combined with each other by the binder resin, the first magnetic part may have fewer defects and less damage due to impact in a large area.

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 an Fe-Si-Al alloy magnetic powder or a Ni-Fe alloy magnetic powder, and more specifically, a sandust powder or 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.

In addition, the magnetic powder may be a nanocrystalline magnetic powder, for example, may be a Fe-based nanocrystalline magnetic powder, specifically, Fe-Si-Al-based nanocrystalline magnetic powder, Fe-Si-Cr It may be a nanocrystalline magnetic powder based on nanocrystalline or Fe-Si-B-Cu-Nb based nanocrystalline magnetic powder.

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 includes 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 moiety 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.

Characteristics of the first magnetic part

The first magnetic part may have a magnetic characteristic of a certain range in the vicinity of the wireless charging standard frequency of the electric vehicle. At a frequency of 85 kHz of the first magnetic part, the magnetic permeability may be 5 to 130, 15 to 80, or 10 to 50, and the investment loss may be 0 to 20, 0 to 15, or 0 to 5.

In addition, 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 property is difficult to obtain in a ceramic-based magnetic material 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 if 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 within 10%.

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 from a height of 1 m to the first magnetic part 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 it is within the above range, the inductance change rate before and after the impact is relatively small, so that the stability of the magnetic part may be further improved.

In addition, the first magnetic part is free-falling from a height of 1 m and the quality factor (Q factor; Ls/Rs) change rate before and after the applied impact is 0% to 5%, 0.001% to 4%, or 0.01% to 2.5% can be When it is within the above range, there is little change in characteristics before and after the impact, so that 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 it is 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 characteristics of the large-area magnetic part may be more stably maintained even if impact or distortion occurs repeatedly.

three-dimensional structure of the first magnetic part

According to the embodiment, by applying a three-dimensional structure to the first magnetic part, charging efficiency and heat dissipation characteristics may be improved. Referring to FIGS. 3A and 3B , the first magnetic part 300 includes an outer part 310 corresponding to a part where the coil part 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. Alternatively, referring to FIGS. 4A and 4B , in the first magnetic part 300 , the thickness of the outer part and the central part may be the same.

In this way, 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 magnetic part in the center, where the electromagnetic energy density is relatively low 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 unit and the shield unit without a separate spacer, thereby reducing material and processing costs due to the use of spacers.

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, the charging efficiency can be improved by more effectively focusing the electromagnetic waves concentrated around the coil, 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 center 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.

Composition and characteristics of the second magnetic part

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

For example, the oxide-based magnetic material may be a ferritic magnetic 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 sintered body may be manufactured in the form of a sheet or block by mixing raw material components, calcining and pulverizing, mixing this with a binder resin, molding, and firing.

More specifically, the oxide-based magnetic material may be a Ni-Zn-based, Mg-Zn-based, or Mn-Zn-based ferrite. In particular, the Mn-Zn-based ferrite has a high temperature range from room temperature to 100° C. or higher at a frequency of 85 kHz. Permeability, low investment loss, and high saturation magnetic flux density can be exhibited.

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%, and 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 the resin in an appropriate amount and press-molding using a press, the temperature is raised to 1200° C. to 1300° C. and calcined for 2 hours or more to produce a sheet or block form. Thereafter, if necessary, it is processed using a wire saw or a water jet and cut to a required size.

In addition, the metal-based magnetic material may be a Fe-Si-Al alloy magnetic material or a Ni-Fe alloy magnetic material, and more specifically, sandust (sendust) or permalloy (permalloy). In addition, the second magnetic part may include a nanocrystalline magnetic material, for example, a Fe-based nanocrystalline magnetic material, specifically, a Fe-Si-Al-based nanocrystalline magnetic material, Fe-Si-Cr-based nanocrystal. It may include a magnetic magnetic material, or a Fe-Si-B-Cu-Nb-based nanocrystalline magnetic material. When the nanocrystalline magnetic material is applied to 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 is lowered, so that the quality factor of the coil (Q factor: Ls/Rs) ) can be increased to improve charging efficiency and reduce heat generation.

The second magnetic part may be formed of a magnetic material different from that of the first magnetic part. As a specific example, the first magnetic part may include a Fe-Si-Al-based alloy magnetic material, and the second magnetic part may include Mn-Zn-based ferrite. The combination of these materials is advantageous in that the second magnetic part has a higher magnetic permeability at 85 kHz than the first magnetic part.

The second magnetic unit may have a magnetic characteristic in a specific range near the wireless charging standard frequency of the electric vehicle. As a specific example, the second magnetic unit may have a magnetic permeability of 1,000 to 5,000, or 2,000 to 4,000 at a frequency of 85 kHz, and an investment loss of 0 to 1,000, 0 to 100, or 0 to 50.

Areas and thicknesses of the first magnetic part and the second magnetic part

The first magnetic part may have a large area, specifically 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. In addition, the first magnetic part having a large area may be configured by combining a plurality of magnetic units, and in this case, the area of the magnetic units may be 60 cm ² or more, 90 cm ² or more, 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. The 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.

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

Specifically, the laminate of the magnetic sheets may be one in which one or more additional magnetic sheets are further laminated only on the outer portion of the first magnetic part. In this case, the individual magnetic sheet may have a thickness of 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.

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

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. A thickness of the outer portion of the first magnetic portion may be greater than a thickness of the second magnetic portion. For example, the thickness of the outer portion may be 5 mm to 11 mm, and the thickness of the central portion may be 0.5 mm to 3 mm.

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

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. In addition, the large-area second magnetic part may be configured by combining a plurality of magnetic units, and in this case, the area of the magnetic units may be 60 cm ² or more, 90 cm ² or more, or 95 cm ² to 900 cm ² .

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.

Composition and characteristics of heat dissipation part

The wireless charging device according to the embodiment may further include a heat dissipation unit for effective heat transfer. During wireless charging, a lot of heat is generated in the magnetic part in proportion to the amount of the focused magnetic flux and the investment loss, and the heat dissipation part can effectively transfer the heat generated in the magnetic part to the outside.

The heat dissipation unit may have a sheet shape, that is, the heat dissipation unit may include a heat dissipation sheet.

The heat dissipation unit may include a binder resin and a heat dissipation filler dispersed in the binder resin. As such, the heat dissipation unit may include a polymer component to exert adhesive force between the shield unit and the magnetic sheet, and may also prevent the magnetic unit from being destroyed by an external impact.

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 includes 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 moiety 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).

As a specific example, the binder resin may be one or more types of silicone-based resins and acrylic-based resins.

In addition, the heat dissipation filler may be one or more of ceramic particles, carbon particles, and metal particles. The ceramic particles may include an oxide or nitride of a metal, specifically silica, alumina, boron nitride, aluminum nitride, magnesium oxide, and the like. The carbon particles may include graphite, carbon black, carbon nanotubes, and the like. The metal particles may include copper, silver, iron nickel, and the like.

The content of the heat dissipation filler in the heat dissipation part may be 70 wt% to 90 wt%, 70 wt% to 85 wt%, or 75 wt% to 90 wt%.

The thermal conductivity of the heat dissipation part may be 0.5 W/m.K to 30 W/m.K, and specifically 2 W/m.K to 5 W/m.K.

The thickness of the heat dissipation part may be 0.1 mm to 5 mm, specifically, 0.1 mm to 3 mm, or 0.2 mm to 1 mm.

The heat dissipation unit may have the same area as the first magnetic unit or the second magnetic unit, or may have a different area from that of the first magnetic unit or the second magnetic unit. For example, when the heat dissipation unit is disposed on the outer portion of the first magnetic unit, the heat dissipation unit may have an area corresponding to the area of the outer portion. In addition, when the heat dissipation unit is disposed between the second magnetic unit and the shield unit, the heat dissipation unit may have an area corresponding to the area of the second heat dissipation material. Accordingly, the heat dissipation unit may exhibit excellent heat dissipation characteristics, adhesion, and impact resistance even with a small area.

Arrangement of the second magnetic part and the heat dissipation part

The first magnetic part and the second magnetic part may be spaced apart from each other. Specifically, the second magnetic part may be disposed between the shield part and the first magnetic part to be spaced apart from the first magnetic part. As a result, during wireless charging, magnetic flux distribution between the first magnetic part and the second magnetic part and heat generated accordingly can be appropriately adjusted. In addition, appropriate durability against external forces such as external shock or distortion that may be applied while the electric vehicle is driving may be provided.

For example, the separation distance between the first magnetic part and the second magnetic part is 1 mm or more, 2 mm or more, 3 mm or more, 1 mm to 30 mm, 1 mm to 20 mm, 1 mm to 10 mm, 2 mm to 7 mm, 3 mm to 10 mm, 3 mm to 5 mm, or 5 mm to 10 mm.

Specifically, the shortest distance between the first magnetic part and the second magnetic part may be 1 mm to 20 mm. More specifically, the shortest distance between the outer portion of the first magnetic portion and the second magnetic portion may be 3 mm to 10 mm. When it is within the above range, it is advantageous to distribute the magnetic flux focused during wireless charging and to control heat accordingly, and it can be given adequate durability against external forces generated during vehicle driving.

In addition, the wireless charging device may further include a heat dissipation unit disposed between the second magnetic unit and the shield unit, and the heat dissipation unit may contact the second magnetic unit and the shield unit at the same time. More specifically, the heat dissipation unit may adhere the second magnetic unit and the shield unit. Accordingly, the heat generated by the second magnetic part may be transferred to the shield part through the heat dissipation part and may be easily discharged to the outside.

3A to 4B, the second magnetic part 500 is disposed between the shield part 400 and the first magnetic part 300, and the heat dissipation part 700 is the second magnetic part. 500 and the shield 400 may be in contact at the same time. As described above, by disposing the second magnetic part having a higher magnetic permeability than the first magnetic part close to the shield part, it is possible to effectively disperse the high magnetic flux density around the coil, 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 heat that is concentrated in the vicinity of the coil of the first magnetic part. In addition, at this time, heat generated from the second magnetic part may be effectively transferred to the shield part through the heat dissipation part.

For example, when the second magnetic part is in the form of a sheet, an entire surface of the second magnetic part may be attached to the shield part via the heat dissipation part. Specifically, the second magnetic part may be attached to one surface of the shield part facing the first magnetic part via the heat dissipation part.

The second magnetic part 500 may be disposed on the outer part, the central part, or both. 3B and 4B , the second magnetic part 500 may be disposed on both the outer part 310 and the central part 320 . Alternatively, as shown in FIGS. 3A and 4A , the second magnetic part 500 may be disposed at a position corresponding to the outer part 310 . Accordingly, a high magnetic flux density around the coil can be effectively dispersed, and thus charging efficiency can be increased compared to the case of using the first magnetic part alone.

housing

The wireless charging device 10 according to the embodiment may further include a housing 600 for protecting the above-described components.

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

tray

3A to 4B , the wireless charging device 10 according to the embodiment may further include a tray 800 disposed between the first magnetic unit 300 and the shield unit 400 . Specifically, the wireless charging device 10 according to the embodiment may further include a tray 800 disposed between the first magnetic part 300 and the second magnetic part 500 .

The tray may serve not only as a housing for fixing the second magnetic part, but also as a spacer for separating the second magnetic part from the first magnetic part. That is, the second magnetic part may be disposed to be spaced apart from the first magnetic part by the tray.

The tray may include a seating groove for accommodating the second magnetic part. Accordingly, the second magnetic part may be accommodated in the seating groove. In this case, the tray may serve as a housing of the second magnetic part, so that a separate adhesive or structure for fixing the second magnetic part may not be required. For example, the depth of the seating groove formed in the tray may be the same as or different from the thickness (height) of the second magnetic part. In addition, when a heat dissipation unit is further disposed on the second magnetic unit, the depth of the seating groove formed in the tray may be equal to the sum of thicknesses of the second magnetic unit and the heat dissipation unit.

Also, the tray may be in contact with the shield part, and specifically, the tray may be fixed to the shield part. In addition, the first magnetic part (for example, an outer part of the first magnetic part) may be disposed in contact with the first magnetic part.

Alternatively, the tray may be disposed to be spaced apart from the shield part or the first magnetic part by a predetermined interval. For example, the separation distance between the tray and the shield part, or the separation distance between the tray and the first magnetic part (eg, the outer part of the first magnetic part) may be 0.5 mm or more or 1 mm or more, specifically 0.5 mm to 5 mm, or 1 mm to 3 mm.

The tray may be made of a plastic material, specifically, a heat-resistant plastic material. Specifically, the plastic material may be a thermoplastic polyimide. In addition, the glass transition temperature (Tg) of the plastic material may be 230 °C to 360 °C, specifically, about 250 to 310 °C.

In addition, the tray may further include a heat dissipation filler, wherein the material of the heat dissipation filler may be at least one selected from the group consisting of a ceramic material, an oxide material, and a carbon material, and more specifically, Al ₂ O ₃ , AlN, SiO ₂ , and Si ₃ N ₄ may be at least one selected from the group consisting of. Accordingly, heat generated from the first magnetic part or the second magnetic part may be transferred to the shield part through the tray.

[transportation]

The wireless charging device according to the embodiment 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.

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 moving means 1 according to an embodiment includes the wireless charging device according to the embodiment as the receiver 21 . The wireless charging device may serve as the receiver 21 of the wireless charging of the mobile means 1 and receive power from the transmitter 22 of the 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 having a higher magnetic permeability than the first magnetic part; and a shield portion disposed on the second magnetic portion, wherein the second magnetic portion is thermally connected to the shield portion.

The configuration and characteristics of each component of the wireless charging device included in the moving means 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.

1: means of transportation (electric vehicle), 10: wireless charging device,
21: receiver, 22: transmitter,
100: support plate, 200: coil unit,
300: a first magnetic part;
310: outer portion, 320: center,
400, 400': a shield unit, 500: a second magnetic unit,
600: housing, 700: heat dissipation unit,
800: tray.

Claims (10)

coil unit;
a first magnetic unit spaced apart from the coil unit to form a space therebetween;
a second magnetic part spaced apart from the first magnetic part to form a space therebetween and having a higher magnetic permeability than the first magnetic part; and
a shield portion disposed on the second magnetic portion;
The second magnetic part is thermally connected to the shield part,
When the wireless power from the outside is received by the coil unit, the amount of heat generated by the second magnetic part is greater than the amount of heat generated by the first magnetic part, the wireless charging device.
delete The method of claim 1,
The volume of the first magnetic part is greater than the volume of the second magnetic part, the wireless charging device.
The method of claim 1,
The shortest distance between the first magnetic part and the second magnetic part is 1 mm to 20 mm, a wireless charging device.
The method of claim 1,
The wireless charging device further comprises a tray disposed between the first magnetic part and the second magnetic part,
The tray includes a seating groove for accommodating the second magnetic part,
The tray is fixed to the shield portion, a wireless charging device.
The method of claim 1,
The wireless charging device further includes a heat dissipation unit disposed between the second magnetic unit and the shield unit, wherein the heat dissipation unit is in contact with the second magnetic unit and the shield unit at the same time.
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 greater than the thickness of the central portion, the wireless charging device.
8. The method of claim 7,
The thickness of the outer portion is greater than the thickness of the second magnetic portion, the wireless charging device.
8. The method of claim 7,
The second magnetic part is disposed at a position corresponding to the outer part, a wireless charging device.
including a wireless charging device;
The wireless charging device
coil unit;
a first magnetic unit spaced apart from the coil unit to form a space therebetween;
a second magnetic part spaced apart from the first magnetic part to form a space therebetween and having a higher magnetic permeability than the first magnetic part; and
a shield portion disposed on the second magnetic portion;
The second magnetic part is thermally connected to the shield part,
When the wireless power from the outside is received by the coil unit, the amount of heat generated by the second magnetic unit is greater than the amount of heat generated by the first magnetic unit.

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