Wireless charging device and vehicle including the same

Abstract

The wireless charging device according to an embodiment can effectively discharge heat by including an insulating heat dissipation part inside the magnetic part or between the magnetic part and the coil part. Accordingly, the wireless charging device can be effectively used for a vehicle, such as an electric vehicle, which requires high-capacity power transmission between a transmitter and a receiver.

Description

Technical Field

[0001] The embodiments relate to a wireless charging device and a vehicle including the wireless charging device. More specifically, the embodiments relate to a wireless charging device that improves charging efficiency through a heat dissipation structure and a vehicle including the wireless charging device, such as an electric vehicle. Background Art

[0002] In recent years, the information and communication field has been developing at an extremely rapid pace, and various technologies that comprehensively combine power, electronics, communication, semiconductors, etc. have been continuously developing. In addition, as electronic devices become more and more mobile, research on wireless communication and wireless power transmission technologies is actively carried out in the communication field. In particular, research on methods for wirelessly transmitting power to electronic devices is being actively conducted.

[0003] Wireless power transmission refers to wirelessly transmitting power through space using inductive coupling, capacitive coupling, or an electromagnetic field resonance structure such as an antenna without physical contact between a power transmitter and a power receiver. Wireless power transmission is applicable to portable communication devices that require large-capacity batteries, electric vehicles, etc. Since the contacts are not exposed, the risk of short circuit is very small, and charging failure phenomena in the wired method can be prevented. [[ID=B]]

[0004] At the same time, with the rapid increase in interest in electric vehicles in recent years, interest in building charging infrastructure has also increased. Various charging methods have emerged, such as charging an electric vehicle using a home charger, replacing the battery, fast charging devices, and wireless charging devices. A new charging business model has also started to emerge (see Korean Patent Publication No. 2011-0042403). In addition, electric vehicles and charging stations under test are starting to stand out in Europe. In Japan, electric vehicles and charging stations are being piloted, led by automobile manufacturers and power companies.

[0005] [Prior Art Documents]

[0006] (Patent Document 1) Korean Patent Publication No. 2011-0042403 Summary of the Invention

[0007] Technical Problem

[0008] In a conventional wireless charging device for an electric vehicle, as Figure 3 The figure shows, a magnetic unit (300') is disposed near a coil unit (200') to improve wireless charging efficiency, and a shielding unit (400') for electromagnetic shielding is disposed at a predetermined interval from the magnetic unit (300').

[0009] During wireless charging operation, the wireless charging device generates heat due to the resistance of the coil unit and the magnetic loss of the magnetic unit. In particular, the magnetic unit in the wireless charging device generates heat in the part close to the coil unit with high electromagnetic wave energy density. The generated heat may change the magnetic properties of the magnetic unit and cause impedance mismatch between the transmitter and the receiver, thereby reducing the charging efficiency. As a result, the generation of heat is exacerbated in turn. However, since such a wireless charging device is installed at the lower part of an electric vehicle, a sealed structure is adopted to prevent dust, water, and shock. Therefore, it is difficult to implement a heat dissipation structure.

[0010] As a result of the research conducted by the present inventor, it has been found that if an insulating heat dissipation unit is provided inside the magnetic unit or between the magnetic unit and the coil unit, heat can be easily dissipated.

[0011] Accordingly, the problem to be solved in this embodiment is to provide a wireless charging device capable of effectively dissipating heat and a vehicle including the wireless charging device.

[0012] Solution to the problem

[0013] According to one embodiment, there is provided a wireless charging device including a coil unit including a wire; a shielding unit disposed on the coil unit; a magnetic unit disposed between the coil unit and the shielding unit; and an insulating heat dissipation unit disposed inside the magnetic unit or between the magnetic unit and the coil unit.

[0014] According to another embodiment, there is provided a vehicle including a wireless charging device, the wireless charging device including a housing; a coil unit disposed inside the housing and including a wire; a shielding unit disposed on the coil unit; a magnetic unit disposed between the coil unit and the shielding unit; and an insulating heat dissipation unit disposed inside the magnetic unit or between the magnetic unit and the coil unit.

[0015] Advantageous effects of the invention

[0016] The wireless charging device of this embodiment is provided with a heat dissipation unit near the heat-generating coil unit or magnetic unit, and can effectively dissipate heat.

[0017] Specifically, in the wireless charging device, the heat dissipation unit can be disposed between the magnetic unit and the coil unit to simultaneously handle the heat generated by the magnetic unit and the coil unit, or can be disposed inside the magnetic unit to effectively handle the heat generated inside the magnetic unit. In addition, the heat dissipation unit can be connected to the shielding unit to effectively dissipate heat to the outside.

[0018] Therefore, the wireless charging device can be advantageously used in vehicles such as electric vehicles that require high-capacity power transmission between the transmitter and the receiver. Description of the drawings

[0019] Figure 1 Exploded perspective view of a wireless charging device according to an embodiment.

[0020] Figures 2a to 2c Shows various examples of cross-sectional views of the wireless charging device.

[0021] Figure 3 Exploded perspective view of a conventional wireless charging device.

[0022] Figure 4 Shows an electric vehicle provided with a wireless charging device as a receiver.

[0023] <Reference numeral description>

[0024] 1: Electric vehicle

[0025] 10: Wireless charging device according to an embodiment

[0026] 10: Wireless charging device of the prior art

[0027] 21: Receiver 22: Transmitter

[0028] 100, 100': Support unit 200, 200': Coil unit

[0029] 300, 300': Magnetic unit 400, 400': Shielding unit

[0030] 500: Heat dissipation unit 550: Thermal conductive medium

[0031] 600: Housing

[0032] Best mode for carrying out the present invention

[0033] In the following description of the embodiments, when it is mentioned that one element is formed "on" or "under" another element, this means not only that one element is directly formed "on" or "under" another element, but also that one element is indirectly formed above or below another element with other elements interposed therebetween.

[0034] Furthermore, the terms "above" or "below" with respect to each element may refer to the drawings. For ease of explanation, the dimensions of the respective elements in the drawings may be exaggerated and they may be different from the actual dimensions.

[0035] Throughout the specification, when a component is referred to as "including" an element, it should be understood that other elements may be included, rather than excluding other elements, unless otherwise clearly stated.

[0036] Furthermore, unless otherwise specified, all numbers representing the features, dimensions, etc. of the elements used herein should be understood to be modified by the term "about".

[0037] In this specification, singular expressions are understood to include singular or plural expressions, as interpreted in the context, unless otherwise specified.

[0038] Wireless charging device

[0039] Figure 1 is an exploded perspective view of a wireless charging device according to an embodiment.

[0040] Reference Figure 1 , a wireless charging device (10) according to an embodiment includes a coil unit (200), the coil unit (200) including a wire; a shielding unit (400) disposed on the coil unit (200); a magnetic unit (300) disposed between the coil unit (200) and the shielding unit (400); and an insulating heat dissipation unit (500) disposed inside the magnetic unit (300) or between the magnetic unit (300) and the coil unit (200).

[0041] Hereinafter, each component of the wireless charging device will be described in detail.

[0042] Coil unit

[0043] The coil unit includes a wire.

[0044] The wire includes a conductive material. For example, the wire may include a conductive metal. Specifically, the wire may include at least one metal selected from the group consisting of copper, nickel, gold, silver, zinc, and tin.

[0045] In addition, the wire may have an insulating sheath. For example, the insulating sheath may include an insulating polymer resin. Specifically, the insulating sheath may include polyvinyl chloride (PVC) resin, polyethylene (PE) resin, polytetrafluoroethylene resin, silicone resin, polyurethane resin, etc.

[0046] The wire may have a diameter of, for example, 1 mm to 10 mm, 1 mm to 5 mm, or 1 mm to 3 mm.

[0047] The wire may be wound in the form of a planar coil. Specifically, the planar coil may include a planar spiral coil. In addition, the planar shape of the coil may be circular, elliptical, polygonal, or polygonal with rounded corners, but is not particularly limited thereto.

[0048] The planar coil may have an outer diameter of 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.

[0049] In addition, the planar coil may have an inner diameter of 0.5 cm to 30 cm, 1 cm to 20 cm, or 2 cm to 15 cm.

[0050] The number of turns of the planar coil can 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, a planar coil can be formed by winding a wire 10 - 30 times.

[0051] In addition, the distance between the wires in the shape of the planar coil can be 0.1 cm to 1 cm, 0.1 cm to 0.5 cm, or 0.5 cm to 1 cm.

[0052] Within the preferred size and specifications of the planar coil described above, it can be suitably used in fields such as electric vehicles that require high - capacity power transmission.

[0053] Shielding unit

[0054] The shielding unit is disposed on the coil unit.

[0055] The shielding unit suppresses electromagnetic interference (EMI) that may be generated due to electromagnetic wave leakage to the outside through electromagnetic shielding.

[0056] The shielding unit can be set at a predetermined interval from the coil unit. For example, the spacing distance between the shielding unit and the coil unit can be 10 mm or more or 15 mm or more, specifically, 10 mm to 30 mm or 10 mm to 20 mm.

[0057] The material of the shielding unit can be, for example, metal. Therefore, the shielding unit can be a metal plate, but is not particularly limited thereto.

[0058] As a specific example, the material of the shielding unit can be aluminum. Other metal or alloy materials with electromagnetic wave shielding capabilities can be used.

[0059] The shielding unit can have a thickness of 0.2 mm to 10 mm, 0.5 mm to 5 mm, or 1 mm to 3 mm. In addition, the shielding unit can have an area of 200 cm 2 or more, 400 cm 2 or more, or 600 cm 2 or more.

[0060] Magnetic unit

[0061] The magnetic unit is disposed between the coil unit and the shielding unit.

[0062] The magnetic unit can be set at a predetermined interval from the shielding unit. For example, the spacing distance between the magnetic unit and the shielding unit can be 3 mm or more, 5 mm or more, 3 mm to 1 mm, or 4 mm to 7 mm.

[0063] In addition, the magnetic unit can be arranged at a predetermined interval from the coil unit. For example, the interval distance between the magnetic unit and the coil unit can 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.

[0064] The magnetic unit can be a polymer-based magnetic material containing an adhesive resin and magnetic powder. Alternatively, the magnetic unit can include a metallic magnetic material, such as a nanocrystalline magnetic material. Alternatively, the magnetic unit can be a composite material of a polymer-based magnetic material and a nanocrystalline magnetic material.

[0065] Polymer-based magnetic material

[0066] The magnetic unit can include a polymer-based magnetic material. Specifically, it can contain an adhesive resin and magnetic powder dispersed in the adhesive resin.

[0067] As a result, since the magnetic powder is bonded to each other by the adhesive resin, the polymer-based magnetic material can have fewer defects over a large area and less damage caused by impact.

[0068] The magnetic powder can be an oxide-based magnetic powder such as ferrite (Ni-Zn system, Mg-Zn system, Mn-Zn system ferrite, etc.); a metallic magnetic powder such as permalloy, iron-silicon-aluminum alloy, nanocrystalline magnetic material; or a mixed powder thereof. More specifically, the magnetic powder can be iron-silicon-aluminum chips particles having an Fe-Si-Al alloy composition.

[0069] For example, the magnetic powder can have the composition of Formula 1 below.

[0070] [Formula 1]

[0071] Fe 1-a-b-c Si a X b Y c

[0072] In the above formula, X is Al, Cr, Ni, Cu, or a combination thereof; Y is Mn, B, Co, Mo, or a combination thereof; 0.01 ≤ a ≤ 0.2, 0.01 ≤ b ≤ 0.1, and 0 ≤ c ≤ 0.05.

[0073] The average particle size of the magnetic powder can be in the range of about 3 nm to 1 mm, about 1 μm to 300 μm, about 1 μm to 50 μm, or about 1 μm to 10 μm.

[0074] The polymer-based magnetic material can contain 50% by weight or more, 70% by weight or more, or 85% by weight or more of magnetic powder.

[0075] For example, the polymer magnetic material may contain 50% to 99% by weight, 70% to 95% by weight, 70% to 90% by weight, 75% to 90% by weight, 75% to 95% by weight, 80% to 95% by weight, or 80% to 90% by weight of magnetic powder.

[0076] The binder resin may be a curable resin. Specifically, the binder resin may include a photocurable resin, a thermosetting resin, and / or a highly heat-resistant thermoplastic resin. Preferably, it may contain a thermosetting resin.

[0077] A resin containing at least one functional group or moiety curable 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 curable by active energy, such as an epoxy group, a cyclic ether group, a thioether group, an acetal group, or a lactone group, can be used as the resin that can be cured to exhibit adhesiveness. Such a functional group or moiety may be, for example, an isocyanate group, a hydroxyl group, or a carboxyl group.

[0078] Specifically, examples of the curable resin include polyurethane resins, acrylic resins, polyester resins, isocyanate resins, or epoxy resins having at least one functional group or moiety as described above, but are not limited thereto.

[0079] As an example, the binder resin may include a polyurethane-based resin, an isocyanate-based curing agent, and an epoxy-based resin.

[0080] The polymer magnetic material may contain 5% to 40% by weight, 5% to 20% by weight, 5% to 15% by weight, or 7% to 15% by weight of the binder resin.

[0081] Furthermore, the polymer magnetic material may contain, based on its weight, 6% to 12% by weight of a polyurethane resin, 0.5% to 2% by weight of an isocyanate curing agent, and 0.3% to 1.5% by weight of an epoxy resin as the binder resin.

[0082] The polymer magnetic material can be prepared by a process of forming a slurry by mixing magnetic powder with a polymer resin composition, shaping it into a sheet, and curing the sheet-shaped mold. To prepare a polymer magnetic material with a large area and a constant thickness, it can be prepared into a block by a molding method using a mold.

[0083] Conventional sheet forming or block forming methods can be applied to the preparation process.

[0084] Nanocrystalline magnetic material

[0085] The magnetic unit may include a nanocrystalline magnetic material.

[0086] If nanocrystalline magnetic materials are used, the farther the distance from the coil unit, even if the inductance (Ls) of the coil unit decreases, the resistance (Rs) will also be lower, so that the quality factor (Q factor: Ls / Rs) of the coil unit increases, which can improve the charging efficiency and reduce heat generation.

[0087] For example, the nanocrystalline magnetic material can be an iron-based nanocrystalline magnetic material. Specifically, it can be an Fe-Si-Al-based nanocrystalline magnetic material, an Fe-Si-Cr-based nanocrystalline magnetic material, or an Fe-Si-B-Cu-Nb-based nanocrystalline magnetic material.

[0088] More specifically, the nanocrystalline magnetic material can be an Fe-Si-B-Cu-Nb-based nanocrystalline magnetic material. In this case, Fe can be 70% to 85% of the elements, the sum of Si and B can be 10% to 29% of the elements, and the sum of Cu and Nb can be 1% to 5% of the elements (where % of the elements refers to the percentage of the quantity of a specific element in the total number of elements). Within the above composition range, the Fe-Si-B-Cu-Nb-based alloy can easily form a nanocrystalline magnetic material through heat treatment.

[0089] The nanocrystalline magnetic material is prepared by, for example, a rapid solidification process (RSP) by melt-spinning an iron-based alloy. It can be prepared by zero-field heat treatment at a temperature range of 300°C to 700°C for 30 minutes to 2 hours.

[0090] If the heat treatment temperature is lower than 300°C, nanocrystals cannot be fully formed, and the required magnetic permeability that requires a long heat treatment time cannot be obtained. If it exceeds 700°C, overheat treatment may significantly reduce the magnetic permeability. In addition, when the heat treatment temperature is low, the treatment time is long. On the other hand, when the heat treatment temperature is high, it is preferable to shorten the treatment time.

[0091] At the same time, due to the characteristics of the preparation process, it is difficult to make the nanocrystalline magnetic material thick. For example, it can be formed into a thin sheet with a thickness of 15μm to 35μm. Therefore, multiple such thin film sheets can be laminated to form a magnetic unit. In this case, an adhesive layer, such as a tape, can be inserted between the thin sheets. In addition, the nanocrystalline magnetic material can be crushed by a pressure roller or the like at the end of the manufacturing process to form multiple cracks in the thin sheet, whereby it can be made into a structure including multiple nanocrystalline fine sheets.

[0092] The area and thickness of the magnetic unit

[0093] The magnetic unit can be a magnetic sheet, a magnetic sheet laminate, or a magnetic block.

[0094] The magnetic unit can have a large area. Specifically, it can have 200 cm 2 or more, 400 cm2 or larger, or 600 cm 2 or larger in area. Additionally, the magnetic unit can have an area of 10,000 cm 2 or smaller.

[0095] The large-area magnetic unit can be constructed by combining multiple unit magnetic materials. In this case, the area of a single unit magnetic material can be 60 cm 2 or larger, 90 cm 2 or 95 cm 2 up to 900 cm 2 .

[0096] The magnetic sheet can have a thickness of 15 μm or larger, 50 μm or larger, 80 μm or larger, 15 μm to 150 μm, 15 μm to 35 μm, or 85 μm to 150 μm. Such a magnetic sheet can be prepared by the methods for preparing conventional thin films or sheets.

[0097] The magnetic sheet laminate can be a laminate of 20 or more or 50 or more magnetic sheets. Additionally, the magnetic sheet laminate can be a laminate of 150 or less or 100 or less magnetic sheets.

[0098] The magnetic block can have a thickness of 1 mm or larger, 2 mm or larger, 3 mm or larger, or 4 mm or larger. Additionally, the magnetic block can have a thickness of 6 mm or smaller.

[0099] The magnetic properties of the magnetic unit

[0100] The magnetic unit can have a certain level of magnetic properties near the standard frequency of wireless charging for electric vehicles.

[0101] The standard frequency of wireless charging for electric vehicles can be less than 100 kHz, for example, 79 kHz to 90 kHz, specifically, 81 kHz to 90 kHz, and more specifically, about 85 kHz. It is a frequency band different from that applied to mobile electronic devices (such as mobile phones).

[0102] The magnetic permeability of the magnetic unit at 85 kHz may vary depending on the material. It can be 5 or more, for example, 5 to 150,000, and specifically can be in the range of 5 to 300, 500 to 3,500, or 10,000 to 150,000, depending on the specific material. Additionally, the magnetic permeability loss of the magnetic unit at 85 kHz may vary depending on the material. According to the specific material, it can be 0 or more, for example, 0 to 50,000 and can specifically be 0 to 1,000, 1 to 100, 100 to 1,000, or 5,000 to 50,000.

[0103] As an example, if the magnetic unit is a polymer-type magnetic block containing magnetic powder and binder resin, at a frequency of 85 kHz, its magnetic permeability can be, for example, 5 to 130, 15 to 80, or 10 to 50, and its magnetic permeability loss can be 0 to 20, 0 to 15, or 0 to 5.

[0104] As another example, if the magnetic unit is a magnetic material based on sintered ferrite, at a frequency of 85 kHz, it can have a magnetic permeability of 1,000 to 5,000 or 2,000 to 4,000 and a magnetic permeability loss of 0 to 1,000, 0 to 100, or 0 to 50.

[0105] As yet another example, if the magnetic unit is a nanocrystalline magnetic material, at a frequency of 85 kHz, it can have a magnetic permeability of 500 to 3,000 or 10,000 to 150,000 and a magnetic permeability loss of 100 to 1,000 or 8,000 to 50,000.

[0106] Features of the magnetic unit

[0107] As an example, the magnetic unit can include a polymer-type magnetic material, and the polymer-type magnetic material can be stretched in a certain proportion. For example, the elongation rate of the polymer-type magnetic material can be 0.5% or more. It is difficult to obtain the elongation characteristic in a ceramic-based magnetic material without applying a polymer. Even if a large-area magnetic unit is deformed due to impact, damage can be reduced. Specifically, the elongation rate of the polymer-type magnetic material can be 0.5% or more, 1% or more, 2.5% or more. There is no particular limitation on the upper limit of the elongation rate. However, if the content of the polymer resin is increased to improve the elongation rate, the characteristics such as the inductance of the magnetic unit may deteriorate. Therefore, the elongation rate is preferably 10% or less.

[0108] Since the impact resistance of the magnetic unit is significantly superior compared to traditional sintered ferrite magnetic materials, the characteristics of the wireless charging device including the magnetic unit change little due to impact.

[0109] In this specification, the characteristic change rate (%) before and after impact can be calculated by the following formula.

[0110] Characteristic change rate (%) = |Characteristic value before impact - Characteristic value after impact| / Characteristic value before impact × 100

[0111] For example, when the magnetic unit is freely dropped from a height of 1 m and subjected to impact, the inductance change rate of the wireless charging device including the magnetic unit is less than 5% or 3% or less before and after impact. More specifically, the change rate of the inductance can be 0% to 3%, 0.001% to 2%, or 0.01% to 1.5%.

[0112] In addition, when the magnetic unit is impacted by free fall from a height of 1 m, the rate of change of the Q factor of the wireless charging device including the magnetic unit before and after the impact may be 0% to 5%, 0.001% to 4%, or 0.01% to 2.5%.

[0113] In addition, when the magnetic unit is impacted by free fall from a height of 1 m, the rate of change of the resistance of the wireless charging device including the magnetic unit before and after the impact can be 0% to 2.8%, 0.001% to 1.8%, or 0.1% to 1.0%.

[0114] In addition, when the magnetic unit is impacted during free fall from a height of 1 m, the rate of change of the charging efficiency of the wireless charging device including the magnetic unit before and after the impact is 0% to 6.8%, 0.001% to 5.8%, or 0.01% to 3.4%.

[0115] Within the above ranges, even in an environment where actual impacts or vibrations are repeatedly applied, the performance of the wireless charging device can be well maintained at a certain level.

[0116] Heat dissipation unit

[0117] The wireless charging device according to the embodiment is provided with a heat dissipation unit adjacent to the magnetic unit or the coil unit that generates heat, whereby heat can be effectively discharged.

[0118] For example, as Figure 2a and 2b shown, the heat dissipation unit (500) can be provided between the magnetic unit (300) and the coil unit (200). In this case, it has the advantage of being able to simultaneously handle the heat generated in the magnetic unit and the coil unit.

[0119] As another example, as Figure 2c shown, the heat dissipation unit (500) can be provided inside the magnetic unit (300). In this case, it has the advantage of being able to effectively handle the heat generated inside the magnetic unit.

[0120] The structure in which the heat dissipation unit is provided inside the magnetic unit can have various design methods. As an example, once the polymer-type magnetic material has been molded by a mold to have an internal space into which the heat dissipation unit is to be inserted, the heat dissipation unit can be inserted therein. As another example, the heat dissipation unit can be inserted between multiple magnetic sheets, and then these magnetic sheets are stacked to prepare a magnetic sheet laminate in which the heat dissipation unit is inserted.

[0121] The heat dissipation unit can be selectively provided in the heat-generating area. For example, as Figure 2bAs shown, the heat dissipation unit (500) can be arranged to correspond to the area where the coil unit (200) is located. In this way, even with a smaller area, the heat dissipation unit can effectively improve the charging efficiency and heat dissipation characteristics.

[0122] The heat dissipation unit can be in direct contact with the heat-generating area to effectively dissipate heat. Specifically, the heat dissipation unit can be in direct contact with at least one of the magnetic unit and the wire. For example, as Figures 2a to 2c shown, the heat dissipation unit (500) can be in direct contact with the magnetic unit (300).

[0123] Alternatively, a thermally conductive adhesive can be used to attach the heat dissipation unit to the heat-generating area. Specifically, a thermally conductive adhesive can be used to attach the heat dissipation unit to the magnetic unit. The thermally conductive adhesive can include thermally conductive materials, such as metal-based, carbon-based, or ceramic-based adhesives, for example, an adhesive resin in which thermally conductive particles are dispersed.

[0124] The heat dissipation unit can be thermally connected to the shielding unit to effectively dissipate the heat generated in the magnetic unit or the coil unit to the outside. Specifically, the heat dissipation unit can be directly connected to the shielding unit or connected through a thermally conductive medium.

[0125] For example, as Figures 2a to 2c shown, the heat dissipation unit (500) can be connected to the shielding unit (400) through a thermally conductive medium (550). The thermally conductive medium can be composed of the same or different components as those of the heat dissipation unit. For example, the thermally conductive medium can be composed of a ceramic material or a carbon-based material. Alternatively, the thermally conductive medium can be composed of the same components as the shielding unit. For example, it can be composed of aluminum.

[0126] Composition of the heat dissipation unit

[0127] The heat dissipation unit can include an adhesive resin and insulating inorganic particles dispersed in the adhesive resin.

[0128] Examples of the adhesive resin include, but are not limited to, polyimide resin, polyamide resin, polycarbonate resin, acrylonitrile-butadiene-styrene (ABS) resin, polypropylene resin, polyethylene resin, polystyrene resin, polyphenylene sulfide (PPS) resin, polyether ether ketone (PEEK) resin, silicone resin, acrylic resin, polyurethane resin, polyester resin, isocyanate resin, and epoxy resin.

[0129] For example, the adhesive resin may be a curable resin. Specifically, the adhesive resin may be a photocurable resin and / or a thermosetting resin. In particular, it may be a resin that can exhibit adhesiveness upon curing. More specifically, the adhesive resin may be a resin containing at least one functional group or moiety 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 epoxy group, a cyclic ether group, a thioether group, an acetal group, or a lactone group. Such a functional group or moiety may be, for example, an isocyanate group, a hydroxyl group, or a carboxyl group.

[0130] As a specific example, the adhesive resin may be one or more of silicone resins and acrylic resins.

[0131] The insulating inorganic particles may comprise a non-carbon inorganic material. That is, it is preferred that the insulating inorganic particles are not carbon-based fillers such as graphite and carbon nanotubes.

[0132] The insulating inorganic particles may include ceramic particles. For example, the insulating inorganic particles may include metal oxides or nitrides. Specifically, the insulating inorganic particles may contain at least one selected from the group consisting of silica, alumina, boron nitride, aluminum nitride, and magnesium oxide.

[0133] The content of the insulating inorganic particles in the heat dissipation unit may be 70% by weight to 90% by weight, 70% by weight to 85% by weight, or 75% by weight to 90% by weight. If the content of the insulating inorganic particles is within the above preferred range, it may be more advantageous from the perspective of thermal conductivity.

[0134] Features of the heat dissipation unit

[0135] The heat dissipation unit may have a sheet-like or strip-like shape.

[0136] The area of the heat dissipation unit may be the same as or different from the area of the magnetic unit. For example, the heat dissipation unit may have a large area that is the same as the magnetic unit. Specifically, the heat dissipation unit may have an area of 200 cm 2 or more, 400 cm 2 or more, or 600 cm 2 or more. In addition, the heat dissipation unit may have an area of 10,000 cm 2 or less. Alternatively, the area of the heat dissipation unit may be smaller than the area of the magnetic unit. Specifically, the area of the heat dissipation unit may correspond to the area of the coil unit.

[0137] The heat dissipation unit may have a thickness of 0.1 mm to 10 mm or 1 mm to 5 mm. The thickness of the heat dissipation unit may be less than the thickness of the magnetic unit. For example, the thickness of the heat dissipation unit may be 1 / 50 to 1 / 2, 1 / 10 to 1 / 2, or 1 / 5 to 1 / 3 of the thickness of the magnetic unit.

[0138] The heat dissipation unit has insulation and thermal conductivity.

[0139] For example, the heat dissipation unit may have a sheet resistance of 10 4 Ω / sq or greater, specifically, 10 6 Ω / sq or greater. In addition, the heat dissipation unit may have a thermal conductivity of 1 W / m·K or greater, specifically, 3 W / m·K or greater, more specifically, 3 W / m·K to 30 W / m·K. Specifically, the heat dissipation unit may have a sheet resistance of 10 4 Ω / sq or greater and a thermal conductivity of 1 W / m·K or greater. Here, the thermal conductivity may be the horizontal thermal conductivity.

[0140] Housing

[0141] The wireless charging device according to an embodiment may further include a housing for accommodating the above components.

[0142] The housing allows components such as a coil unit, a shielding unit, and a magnetic unit to be properly arranged and assembled. The material and structure of the housing may be those of a conventional housing for a wireless charging device and can be appropriately designed according to the components used therein.

[0143] Referring to Figures 2a to 2c , the wireless charging device (10) according to an embodiment includes a housing (600); a coil unit (200) disposed within the housing (600) and including a wire; a shielding unit (400) disposed on the coil unit (200); a magnetic unit (300) disposed between the coil unit (200) and the shielding unit (400); and an insulating heat dissipation unit (500) disposed inside the magnetic unit (300) or between the magnetic unit (300) and the coil unit (200).

[0144] Support unit

[0145] The wireless charging device (10) may further include a support unit (100) for supporting the coil unit. The material and structure of the support unit may be those of a conventional support unit used in a wireless charging device. The support unit may have a flat plate structure or a structure in which a groove is formed to conform to the shape of the coil to fix the coil unit.

[0146] Spacer

[0147] In addition, the wireless charging device according to an embodiment may further include a spacer for ensuring a space between the shielding unit and the magnetic unit. The material and structure of the spacer may be those of a conventional spacer used in a wireless charging device.

[0148] Electric vehicle

[0149] Figure 4A vehicle is shown, specifically, an electric vehicle equipped with a wireless charging device. Since the wireless charging device is provided on its lower side, wireless charging can be performed in a parking lot equipped with a wireless charging system for electric vehicles.

[0150] Reference Figure 4 , the vehicle (1) according to the embodiment includes a wireless charging device according to the embodiment as a receiver (21). The wireless charging device can be used as a receiver for wirelessly charging the vehicle (1) and can receive power from a transmitter (22) for wireless charging.

[0151] The vehicle includes a wireless charging device, which includes a housing; a coil unit disposed within the housing and including a wire; a shielding unit disposed on the coil unit; a magnetic unit disposed between the coil unit and the shielding unit; and an insulating and heat dissipating unit disposed inside the magnetic unit or between the magnetic unit and the coil unit.

[0152] The structures and characteristics of the components of the wireless charging device adopted in the vehicle are as described above.

[0153] The vehicle may further include a battery for receiving power from the wireless charging device. The wireless charging device can wirelessly receive power and transmit it to the battery, and the battery can supply power to the drive system of the vehicle. The battery can be charged by power transmitted from the wireless charging device or other additional wired charging devices.

[0154] In addition, the vehicle may further include a signal transmitter for sending information about charging to the transmitter of the wireless charging system of the vehicle. Such information about charging can be charging efficiency, such as charging speed, charging status, etc.

[0155] Mode of the invention

[0156] Hereinafter, preparation examples and test examples of the magnetic unit used in the wireless charging device according to the embodiment will be described, but the scope of implementation is not limited thereto.

[0157] Preparation Example 1: Preparation of the magnetic unit

[0158] Step 1: Preparation of the magnetic powder slurry

[0159] 42.8 parts by weight of magnetic powder, 15.4 parts by weight of a polyurethane resin dispersion (25% by weight of a polyurethane resin and 75% by weight of 2-butanone), 1.0 part by weight of an isocyanate-based curing agent dispersion (62% by weight of an isocyanate-based curing agent, 25% by weight of n-butyl acetate and 13% by weight of 2-butanone), 0.4 part by weight of an epoxy resin dispersion (70% by weight of an epoxy resin, 3% by weight of n-butyl acetate, 15% by weight of 2-butanone and 12% by weight of toluene), and 40.5 parts by weight of toluene were mixed in a planetary mixer and stirred at a speed of about 40-50 rpm for about 2 hours to prepare a magnetic powder slurry.

[0160] Step 2: Preparation of magnetic sheet stack

[0161] The magnetic powder slurry prepared above was applied to a carrier film using a comma coater and dried at approximately 110°C to form a polymeric magnetic material. The polymeric magnetic material was then compressed and hardened for approximately 60 minutes using a hot press process at approximately 170°C and a pressure of approximately 9 MPa to produce a sheet. The magnetic powder content of the sheet thus prepared was approximately 90% by weight, and the thickness of a single sheet was approximately 100 μm. Forty to fifty of these sheets were stacked to form a magnetic unit having a thickness of approximately 4.8 mm.

[0162] Comparison Examples

[0163] A PC-95 ferrite magnetic sheet (thickness: 5 mm) manufactured by TDK Corporation was used as a comparative example.

[0164] Test Example

[0165] The magnetic units of Preparation Example 1 and Comparative Example were tested in the following manner.

[0166] (1) Elongation

[0167] The elongation was measured on the magnetic unit sample before impact using a UTM device (INSTRON 5982, INSTRON Inc.) by the ASTM D412 type C method.

[0168] (2) Changes in characteristics before and after impact

[0169] When a magnetic unit sample is subjected to an impact while freely falling from a height of 1 m, the electrical characteristics of a device using the magnetic unit sample before and after the impact are calculated by the following formula.

[0170] Characteristic change rate (%) = |characteristic value before impact - characteristic value after impact| / characteristic value before impact × 100

[0171] Using the coil unit and the frame under the SAE J2954 WPT2 Z2 class standard test specification, the magnetic unit, the spacer, and the aluminum plate were stacked together to fabricate a receiving device (35.5 cm × 35.5 cm) and a transmitting device (67.48 cm × 59.1 cm). The electrical characteristics were measured at a frequency of 85 kHz.

[0172] The inductance and the resistance were measured using an LCR meter (IM3533, HIOKI).

[0173] The quality factor was calculated as inductance × frequency × 2π / resistance.

[0174] The charging efficiency was measured under the conditions of an output power of 1000 W and a frequency of 85 kHz.

[0175] The results are shown in Tables 1 and 2 below.

[0176] [Table 1]

[0177]

[0178] [Table 2]

[0179]

[0180] As can be seen from the above table, the elongation rate of the magnetic unit in Preparation Example 1 was 3%, while the elongation rate of the ferrite sheet in the Comparative Example was 0%. In addition, the inductance, quality factor, and resistance of the device using the magnetic unit in Preparation Example 1 before impact were excellent, and the change rate of the measured characteristics after impact was in the range of 0 to 1%. On the contrary, in the ferrite sheet of the Comparative Example, the change rates of the inductance, quality factor, and resistance of the device using it after impact were high. In particular, the change rate (reduction rate) of the charging efficiency was measured to be as high as 3%. From the above confirmation, in an environment such as the driving of an electric vehicle that is vulnerable to impact, compared with the conventional ferrite sheet, the magnetic unit in Preparation Example 1 is suitable for a wireless charging device.

Claims

1. A wireless charging device, the wireless charging device comprising a coil unit, the coil unit including a wire; a shielding unit disposed on the coil unit; a magnetic unit disposed between the coil unit and the shielding unit; and an insulating heat dissipation unit disposed inside the magnetic unit or between the magnetic unit and the coil unit; wherein, The magnetic unit is arranged to be separated from the shielding unit by a predetermined interval, and the heat dissipation unit is connected to the shielding unit through a heat-conducting medium, wherein the magnetic unit includes an adhesive resin and magnetic powder dispersed in the adhesive resin, and wherein the elongation of the magnetic unit measured by the ASTM D412 Type C method is 2.5% to 10%.

2. The wireless charging device according to claim 1, wherein the heat dissipation unit includes an adhesive resin and insulating inorganic particles dispersed in the adhesive resin.

3. The wireless charging device according to claim 2, wherein the insulating inorganic particles include ceramic particles.

4. The wireless charging device according to claim 1, wherein the sheet resistance of the heat dissipation unit is 10 4 Ω / sq or more, and the thermal conductivity is 1 W / m·K or more.

5. The wireless charging device according to claim 1, wherein the heat dissipation unit is in direct contact with at least one of the magnetic unit and the wire.

6. The wireless charging device according to claim 1, wherein the heat dissipation unit is arranged corresponding to the area where the coil unit is located.

7. A vehicle, the vehicle comprising a wireless charging device, the wireless charging device including a housing; a coil unit disposed within the housing and including a wire; a shielding unit disposed on the coil unit; a magnetic unit disposed between the coil unit and the shielding unit; and an insulating heat dissipation unit disposed inside the magnetic unit or between the magnetic unit and the coil unit; wherein, The magnetic unit is arranged to be separated from the shielding unit by a predetermined interval, and the heat dissipation unit is connected to the shielding unit through a heat-conducting medium, wherein the magnetic unit includes an adhesive resin and magnetic powder dispersed in the adhesive resin, and wherein the elongation of the magnetic unit measured by the ASTM D412 Type C method is 2.5% to 10%.

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