Wireless charging device and mobile tool including the same

Abstract

The wireless charging device according to one embodiment includes a fluid channel arranged inside or at a neighboring portion of the magnetic unit, and has a cooling fluid flowing into the fluid channel to contact the magnetic unit, and thus can easily release the heat generated during wireless charging. Therefore, the wireless charging device can be effectively used in mobile tools such as electric vehicles that require large-capacity power transmission between a transmitter and a receiver.

Description

Technical Field

[0001] The present invention relates to a wireless charging device and a mobile tool including the same. More specifically, the present invention relates to a wireless charging device that improves charging efficiency through a heat dissipation structure and a mobile tool including the same, such as an electric vehicle. Background Art

[0002] In recent years, the information and communication fields are developing rapidly, and various technologies that comprehensively combine electricity, electronics, communications, and semiconductors are also developing continuously. In addition, as the mobility of electronic devices increases, research on wireless communication and wireless power transmission technology is being actively carried out in the communication field. In particular, research on methods for wirelessly transmitting electric energy to electronic devices is being actively carried out.

[0003] Wireless power transmission refers to the wireless transmission of power in space using inductive coupling, capacitive coupling, or electromagnetic field resonant structures such as antennas without physical contact between the transmitter that provides power and the receiver that receives power. Wireless power transmission is suitable for portable communication devices, electric vehicles, etc. that require large-capacity batteries. Since the contacts are not exposed, the risk of short circuit is very small, which can prevent the charging failure phenomenon in wired methods.

[0004] At the same time, due to the rapid growth of interest in electric vehicles in recent years, the focus on the construction of charging infrastructure is also increasing. For example, a variety of charging methods for charging electric vehicles using home chargers, battery replacement, fast charging devices, and wireless charging devices have emerged. A new charging business model has also begun to emerge (see Korean Publication Patent, Publication No. 2011-0042403). In addition, electric vehicles and charging stations under testing are also beginning to stand out in Europe. In Japan, electric vehicles and charging stations are being piloted, led by automakers and power companies.

[0005] [Prior art literature]

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

[0007] Technical issues

[0008] In a conventional wireless charging device for an electric vehicle, a magnetic material is disposed adjacent to the coil to improve wireless charging efficiency, and a metal plate for shielding is disposed at a preset interval from the magnetic material.

[0009] During the operation of wireless charging, the wireless charging device generates heat due to the coil resistance and the magnetic loss of the magnetic material. In particular, the part of the wireless charging device where the magnetic material is close to the coil and has a high electromagnetic wave energy density will generate heat. The heat generated will change the magnetic properties of the magnetic material and cause impedance mismatch between the transmitter and the receiver, thereby reducing the charging efficiency. As a result, the heating is aggravated. However, since such wireless charging devices are installed in the lower part of the electric vehicle, they use a sealing structure for dustproof, waterproof and shock absorption. Therefore, it is difficult to set a heat dissipation structure.

[0010] From the research results obtained by the present inventors, it has been found that if a channel is provided inside or near a magnetic unit adopted in a wireless charging device, heat can be easily released through a refrigerant.

[0011] Therefore, the problem solved by this embodiment is to provide a wireless charging device with enhanced heat dissipation and a mobile tool including the same.

[0012] Solutions to the problem

[0013] As described in one embodiment, a wireless charging device is provided, which includes a coil unit; a shielding unit arranged above the coil unit; a magnetic unit arranged between the coil unit and the shielding unit; and a channel arranged inside or near the magnetic unit, wherein a fluid for cooling is introduced into the channel and contacts the magnetic unit.

[0014] As described in another embodiment, a mobile tool is provided, which includes a wireless charging device, wherein the wireless charging device includes a coil unit; a shielding unit arranged above the coil unit; a magnetic unit arranged between the coil unit and the shielding unit; and a channel arranged inside or near the magnetic unit, and a fluid for cooling is introduced into the channel and contacts the magnetic unit.

[0015] Advantageous Effects of the Invention

[0016] Since the wireless charging device according to the embodiment includes a channel disposed inside or near the magnetic unit, and a fluid for cooling is introduced into the channel and contacts the magnetic unit, heat generated during wireless charging can be easily released.

[0017] Therefore, the wireless charging device can be advantageously used in electric vehicles that require large-capacity power transmission between a transmitter and a receiver. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1a FIG. 4 is an exploded perspective view of a wireless charging device according to an embodiment.

[0019] Figure 1b is a cross-sectional view of a wireless charging device according to an embodiment.

[0020] Figure 2 is a cross-sectional view of a wireless charging device according to another embodiment.

[0021] Figure 3a is a cross-sectional view of a wireless charging device according to yet another embodiment.

[0022] Figure 3b FIG. 1 is a plan view of an air circulation unit according to an embodiment.

[0023] Figure 4a is a cross-sectional view of a wireless charging device according to yet another embodiment.

[0024] Figure 4b and 4c They are respectively a perspective view and a plan view of a magnetic unit according to an embodiment.

[0025] Figure 4d FIG. 4 is a plan view of a magnetic unit according to another embodiment.

[0026] Figure 4e FIG. 4 is a plan view of a magnetic unit according to another embodiment.

[0027] Figure 5 is a cross-sectional view of a wireless charging device according to yet another embodiment.

[0028] Figure 6 FIG. 4 is an exploded perspective view of a wireless charging device according to yet another embodiment.

[0029] Figure 7a FIG. 1 is a plan view of a magnetic unit including a microchannel.

[0030] Figure 7b A process of forming a magnetic unit by a mold is illustrated.

[0031] Figures 8a to 8b They are respectively cross-sectional views of a wireless charging device according to yet another embodiment.

[0032] Fig. 9 An example of an electric vehicle to which a wireless charging device is applied is shown.

[0033] Fig.10 An electric vehicle is shown with a wireless charging device as a receiver.

[0034] <Description of Reference Numerals>

[0035] 1: Mobile tools (electric vehicles)

[0036] 2: Injection molding machine 3: Mold

[0037] 15: Cooler 16: Connecting channel

[0038] 21: Receiver 22: Transmitter

[0039] 100, 100', 200, 300, 400, 500, 600: Wireless charging device

[0040] 110, 110', 210, 310, 410, 510, 610: Coil unit

[0041] 120, 120', 220, 320, 420, 420a, 420b, 420c, 520, 620: Magnetic unit

[0042] 130, 130', 230, 330, 430, 530, 630: Shielding unit

[0043] 140, 140', 240, 340, 440, 540: Air circulation unit

[0044] 145, 245, 345, 445, 555: Air (fluid)

[0045] 160, 560, 660: Support unit

[0046] 270, 370, 470: inlet pipe 280, 380, 480: outlet pipe

[0047] 390: Guide wall

[0048] 490: hole 495a, 495b, 495c: cooling channel

[0049] 501, 601: Shell 621: Raw material composition

[0050] 640: cooling unit 695: microchannel

[0051] 670: Entrance 680: Exit DETAILED DESCRIPTION

[0052] In the following description of the embodiments, when mentioning that an element is formed "on" or "under" another element, it not only means that one element is directly formed "on" or "under" another element, but also means that one element is indirectly formed on or under another element with other elements (singular or plural other elements) interposed therebetween.

[0053] In addition, the terms above or below related to each element may refer to the drawings. For convenience of explanation, the sizes of individual elements in the drawings are exaggerated and depicted, and they may be different from the actual sizes.

[0054] Throughout the specification, when it is mentioned that a component “includes” an element, it should be understood that it can include other elements rather than excluding the possibility of including other elements, unless explicitly stated otherwise.

[0055] Furthermore, unless otherwise indicated, all numbers expressing physical properties, dimensions, and the like of elements used herein are to be understood as being modified by the term "about."

[0056] In this specification, unless otherwise specified, a singular expression should be understood as including a singular or plural expression, which is interpreted according to the context.

[0057] Wireless charging device

[0058] The wireless charging device as described in the embodiment includes a coil unit; a shielding unit arranged above the coil unit; a magnetic unit arranged between the coil unit and the shielding unit; and a channel arranged inside or near the magnetic unit, wherein a fluid for cooling is introduced into the channel and contacts the magnetic unit.

[0059] As an example, the wireless charging device may include an air circulation unit provided between the magnetic unit and the shielding unit as a passage. Air as a cooling fluid may be introduced into the air circulation unit and directly contact the surface of the magnetic unit.

[0060] See also Figure 1a and 1b The wireless charging device (100, 100') includes a coil unit (110, 110'), the coil unit (110, 110') includes a wire; a magnetic unit (120, 120') disposed on one side of the coil unit (110, 110'); a shielding unit (130, 130') formed by being spaced apart from the magnetic unit (120, 120'); and an air circulation unit (140, 140') disposed between the magnetic unit (120, 120') and the shielding unit (130, 130'), wherein air (145) is introduced into the air circulation unit (140, 140') and directly contacts the surface of the magnetic unit (120, 120'). The air introduced into the air circulation unit (140, 140') may be air supplied by an external air conditioning system.

[0061] The air conditioning system may include a heat dissipation, ventilation and cooling system of a vehicle. Specifically, it may include an automobile air conditioner.

[0062] Since the wireless charging device according to the embodiment includes an air circulation unit, the air introduced from the outside can circulate through the air circulation unit and directly contact the surface of the magnetic unit, so that the heat generated in the magnetic unit can be circulated and released to the outside while improving the heat dissipation characteristics and charging efficiency. In addition, since the air introduced into the air circulation unit is air supplied by an external air conditioning system, the problem of deterioration of the magnetic unit due to humidity can be solved.

[0063] In addition, see Figure 5 The wireless charging device may further include a supporting unit (560) for supporting the coil unit (510) and a housing (501) for accommodating components.

[0064] As another example, the wireless charging device may include a microchannel disposed inside the magnetic unit as a channel.

[0065] See also Figure 6 The wireless charging device (600) as described in the embodiment includes a coil unit (610), the coil unit (610) includes a wire; a shielding unit (630) arranged on the coil unit (610); a magnetic unit (620) arranged between the coil unit (610) and the shielding unit (630); and a microchannel (695) arranged inside or near the magnetic unit (620).

[0066] Since the wireless charging device as described in the embodiment includes a channel disposed inside or near the magnetic unit, heat can be easily released through the refrigerant. Specifically, since a microchannel is formed inside the magnetic unit and a gaseous or liquid fluid as a refrigerant is connected to an external cooler for circulation, the heat generated in the magnetic unit can be easily released to the outside.

[0067] Each constituent element of the wireless charging device will be described in detail below.

[0068] Coil unit

[0069] The coil unit may include a conductive wire.

[0070] 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 copper, nickel, gold, silver, zinc and tin.

[0071] 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, Teflon resin, silicone resin, polyurethane resin, etc.

[0072] The diameter of the wire may be, for example, 1 mm to 10 mm, 1 mm to 5 mm, or 1 mm to 3 mm.

[0073] 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.

[0074] 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 outer diameter of the planar coil may be 10 cm to 50 cm.

[0075] Furthermore, 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.

[0076] The number of turns of the planar coil may be 5 to 50 times, 10 to 30 times, 5 to 30 times, 15 to 50 times, or 20 to 50 times. As a specific example, the planar coil may be formed by winding the conductive wire 10 to 30 times.

[0077] Furthermore, 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.

[0078] Within the preferred size and specification range of the planar coil, it can be applied to fields requiring large-capacity power transmission, such as electric vehicles.

[0079] The coil unit may be arranged to be spaced apart from the magnetic unit at a preset interval. For example, the interval distance between the coil unit and the magnetic unit may be 0.2 mm or more, 0.5 mm or more, 0.2 mm to 0.3 mm, or 0.5 mm to 1.2 mm.

[0080] Shielding unit

[0081] The shielding unit is disposed above the coil and the magnetic unit.

[0082] The shielding unit suppresses electromagnetic interference (EMI) that may be generated by electromagnetic waves leaking to the outside through electromagnetic shielding.

[0083] The shielding unit may be arranged to be spaced apart from the coil unit at a preset interval. For example, the spacing distance between the shielding unit and the coil unit may be 10 mm or more or 15 mm or more, specifically, 10 mm to 30 mm or 10 mm to 20 mm.

[0084] In addition, the shielding unit may be arranged to be spaced apart from the magnetic unit at a preset interval. For example, the spacing distance between the shielding unit and the magnetic unit may be 3 mm or more, 5 mm or more, 3 mm to 10 mm, or 4 mm to 7 mm.

[0085] The material of the shielding unit may be, for example, metal. Therefore, the shielding unit may be a metal plate, but is not particularly limited thereto. As a specific example, the material of the shielding unit may be aluminum. Other metal or alloy materials having electromagnetic wave shielding capability may also be used.

[0086] The thickness of the shielding unit 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 shielding unit may be 200 cm 2 or above, 400cm 2 or above or 600cm 2 or above.

[0087] Magnetic unit

[0088] The magnetic unit is disposed between the coil unit and the shielding unit.

[0089] The magnetic unit may be arranged to be spaced apart from the coil unit at a preset interval. For example, the interval distance between the magnetic unit and the coil unit may be 0.2 mm or more, 0.5 mm or more, 0.2 mm to 0.3 mm, or 0.5 mm to 1.5 mm.

[0090] The magnetic unit may be a polymer magnetic material including a binder resin and a magnetic powder. Alternatively, the magnetic unit may be a ferrite-based magnetic material, such as a sintered ferrite-based magnetic material. Alternatively, the magnetic unit may include a metal magnetic material, such as a nanocrystalline magnetic material. Alternatively, the magnetic unit may be a composite material of two or more of a polymer magnetic material, a ferrite-based magnetic material, and a nanocrystalline magnetic material.

[0091] Polymer magnetic materials

[0092] The magnetic unit may include magnetic powder and a binder resin.

[0093] Specifically, the magnetic unit may include a binder resin and magnetic powder dispersed in the binder resin. As a result, since the magnetic powder is bonded to each other through the binder resin, the magnetic unit may have fewer defects over a large area and may be less damaged by impact.

[0094] The magnetic powder may be an oxide-based magnetic powder, a metal-based magnetic powder, and a mixed powder thereof. For example, the oxide-based magnetic powder may be a ferrite-based powder, specifically, a Ni-Zn-based, Mg-Zn-based, or Mn-Zn-based ferrite powder. In addition, the metal-based magnetic powder may be a Fe-Si-Al alloy magnetic powder or a Ni-Fe alloy magnetic powder, more specifically, a Sendust powder or a Permalloy powder.

[0095] As an example, the composition of the magnetic powder may be as shown in Formula 1 below.

[0096] [Formula 1]

[0097] Fe 1-a-b-c Si a X b Y c

[0098] 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.

[0099] In addition, the magnetic powder can be a nanocrystalline magnetic powder. For example, it can be a Fe-based nanocrystalline magnetic powder. Specifically, it can be a Fe-Si-Al-based nanocrystalline magnetic powder, a Fe-Si-Cr-based nanocrystalline magnetic powder or a Fe-Si-B-Cu-Nb-based nanocrystalline magnetic powder.

[0100] The average particle size of the magnetic powder may range from about 3 nm to 1 mm, from about 1 μm to 300 μm, from about 1 μm to 50 μm, or from about 1 μm to 10 μm.

[0101] The magnetic unit may include the magnetic powder in an amount of 10% or more by weight thereof, 50% or more by weight thereof, 70% or more by weight thereof, or 85% or more by weight thereof.

[0102] For example, the magnetic unit may include magnetic powder in an amount of 10% to 99% of its weight, 10% to 95% of its weight, 50% to 95% of its weight, 50% to 92% of its weight, 70% to 95% of its weight, 80% to 95% of its weight, or 80% to 90% of its weight.

[0103] Examples of the binder resin include polyimide resin, polyamide resin, polycarbonate resin, acrylonitrile-butadiene-styrene (ABS) resin, polypropylene resin, polyethylene resin, polystyrene resin, polyphenylene sulfide (PPS) resin, polyether etherketone (PEEK) resin, silicone resin, acrylic resin, polyurethane resin, polyester resin, isocyanate resin and epoxy resin, but are not limited thereto.

[0104] For example, the binder resin may be a curable resin. Specifically, the binder resin may be a photocurable resin and / or a thermosetting resin. In particular, it may be a resin that exhibits adhesiveness when cured. More specifically, the resin that may be used as the binder resin may include at least one functional group or part that is capable of thermal curing, 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 part 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 part may be, for example, an isocyanate group (-NCO), a hydroxyl group (-OH), or a carboxyl group (-COOH).

[0105] Alternatively, the binder resin may be a thermoplastic resin, and specifically, a highly heat-resistant thermoplastic resin.

[0106] The magnetic unit may include the resin in an amount of 5% to 40% by weight, 5% to 20% by weight, 5% to 15% by weight, or 7% to 15% by weight.

[0107] In addition, based on its weight, the magnetic unit may include 6% to 12% of its weight of polyurethane resin, 0.5% to 2% of its weight of isocyanate curing agent, and 0.3% to 1.5% of its weight of epoxy resin as a binder resin.

[0108] The magnetic unit may be a magnetic block prepared by a method such as mold molding. For example, the magnetic unit may be a three-dimensional structure molded by a mold. Such a magnetic block may be obtained by mixing magnetic powder and a binder resin and injecting it into a mold by injection molding to mold into a three-dimensional structure.

[0109] Specifically, the raw material of the magnetic unit can be injected into a mold for molding by injection molding. More specifically, the raw material composition can be obtained by mixing magnetic powder and polymer resin components, and then by Figure 7bThe injection molding machine (2) shown injects the raw material components (621) into the mold (3) to prepare the magnetic unit. In this case, the internal shape of the mold (3) can be designed as a three-dimensional structure, so that the three-dimensional structure of the magnetic unit can be easily realized. When using a conventional sintered ferrite sheet as the magnetic unit, this process may be difficult to achieve.

[0110] Ferrite-based magnetic materials

[0111] The ferrite-based magnetic material may include, for example, an oxide represented by MOFe2O3 (wherein M is one or more divalent metal elements, such as Mn, Zn, Cu and Ni). In view of magnetic properties such as magnetic permeability, the ferrite-based magnetic material is preferably a sintered body. The ferrite-based magnetic material may be prepared in a sheet or block form by mixing raw materials, followed by calcination, pulverization, mixing with a binder resin, molding and sintering.

[0112] More specifically, the ferrite-based magnetic material may be Ni-Zn-based, Mg-Zn-based or Mn-Zn-based ferrite. In particular, Mn-Zn-based ferrite may exhibit high magnetic permeability, low magnetic permeability loss and high saturation magnetic flux density at a frequency of 85 kHz and a temperature range of from room temperature to 100° C. or higher.

[0113] Mn-Zn-based ferrite includes 66 mol% to 70 mol% of Fe2O3, 10 mol% to 20 mol% of ZnO, 8 mol% to 24 mol% of MnO, 0.4 mol% to 2 mol% of NiO as main components, and further includes SiO2, CaO, Nb2O5, ZrO2, SnO and the like as additional minor components. Mn-Zn-based ferrite can be prepared into a sheet or block by mixing the main components in a preset molar ratio, calcining it in air at a temperature of 800°C to 1100°C for 1 hour to 3 hours, adding the minor components thereto and grinding it, mixing it with an appropriate amount of a binder resin such as polyvinyl alcohol (PVA), press-molding it using a press machine, and sintering it at a temperature of 1200°C to 1300°C for 2 hours or more. Thereafter, if necessary, it is processed and cut into a desired size using a wire saw or a water jet.

[0114] Nanocrystalline magnetic materials

[0115] The magnetic unit may include nanocrystalline magnetic materials. If nanocrystalline magnetic materials are used as the magnetic unit, the farther away from the coil, the lower the resistance (Rs) even if the inductance (Ls) of the coil is reduced. Therefore, the quality factor (Q value: Ls / Rs) of the coil increases, which can improve charging efficiency and reduce heat generation.

[0116] For example, the magnetic unit may be a Fe-based nanocrystalline magnetic material, specifically, a Fe-Si-Al-based nanocrystalline magnetic material, a Fe-Si-Cr-based nanocrystalline magnetic material, or a Fe-Si-B-Cu-Nb-based nanocrystalline magnetic material.

[0117] More specifically, the magnetic unit can be a Fe-Si-B-Cu-Nb-based nanocrystalline magnetic material. In this case, it is preferred that the element proportion of Fe is 70% to 85%, the sum of the elements of Si and B is 10% to 29%, and the sum of the elements of Cu and Nb is 1% to 5% (wherein, the element proportion % refers to the percentage of the number of specific elements to the total number of elements constituting the magnetic unit). Within the above composition range, the Fe-Si-B-Cu-Nb-based alloy can be easily formed into a nanocrystalline magnetic material by heat treatment.

[0118] The nanocrystalline magnetic material is prepared by a rapid solidification process (RSP) such as melt spinning of an Fe-based alloy, and can be prepared by a zero-field heat treatment at a temperature range of 300° C. to 700° C. for 30 minutes to 2 hours.

[0119] If the heat treatment temperature is lower than 300°C, nanocrystals cannot be fully formed, thereby failing to obtain the desired magnetic permeability requiring a longer heat treatment. If it exceeds 700°C, excessive heat treatment may severely reduce the magnetic permeability. In addition, when the heat treatment temperature is low, the treatment time will be long. On the other hand, when the heat treatment temperature is high, it is preferred that the treatment time will be shortened.

[0120] The thickness of the nanocrystalline magnetic material can be 15 μm to 150 μm. At the same time, it is difficult to prepare thick nanocrystalline magnetic materials due to the characteristics of the preparation process. For example, it can form a thin sheet with a thickness of 15 μm to 35 μm. Therefore, several such thin film sheets can be laminated to form a magnetic unit. In this case, an adhesive layer, such as an adhesive tape, can be inserted between the thin sheets.

[0121] Furthermore, the nanocrystalline magnetic material may be rolled by a pressure roller or the like at the end of the manufacturing process to form a plurality of cracks in the thin sheet, so that it can be made to include a plurality of nanocrystalline flakes.

[0122] Nanocrystalline magnetic materials can have magnetic properties within a range around the standard frequencies used for wireless charging of electric vehicles.

[0123] For example, the nanocrystalline magnetic material may have a magnetic permeability of 500 to 150,000 and a magnetic permeability loss of 100 to 50,000 at a frequency of 85 kHz. As an example, when the magnetic unit includes crushed nanocrystalline magnetic material, it may have a magnetic permeability of 500 to 3,000 and a magnetic permeability loss of 100 to 1,000 at a frequency of 85 kHz. As another example, when the magnetic unit includes uncrushed nanocrystalline magnetic material, it may have a magnetic permeability of 10,000 to 150,000 and a magnetic permeability loss of 1,000 to 10,000 at a frequency of 85 kHz.

[0124] Area and thickness of magnetic unit

[0125] The magnetic unit may be a magnetic sheet, a magnetic sheet laminate or a magnetic block structure.

[0126] The magnetic unit may have a larger area. Specifically, its area may be 200 cm 2 or above, 400cm 2 or above or 600cm 2 In addition, the area of ​​the magnetic unit can be 10000cm 2 or below.

[0127] A magnetic unit with a larger area can be configured by combining multiple unit magnetic materials. In this case, the area of ​​a single unit magnetic material can be 60cm 2 or above, 90cm 2 or above or 95cm 2 Up to 900cm 2 .

[0128] The thickness of the magnetic sheet may be 15 μm or more, 50 μm or more, 80 μm or more, 15 μm to 150 μm, 15 μm to 35 μm, or 85 μm to 150 μm. Such a magnetic sheet may be prepared by a conventional method for preparing a film or sheet.

[0129] The magnetic sheet laminate may be a laminate of 20 or more or 50 or more magnetic sheets. In addition, the magnetic sheet laminate may be a laminate of 150 or less or 100 or less magnetic sheets.

[0130] The thickness of the magnetic block can be 1 mm or more, 2 mm or more, 3 mm or more or 4 mm or more. In addition, the thickness of the magnetic block can be 6 mm or less.

[0131] The magnetic block can be prepared by methods such as injection molding.

[0132] Magnetic properties of magnetic units

[0133] The magnetic unit may have magnetic properties within a certain range around standard frequencies used for wireless charging of electric vehicles.

[0134] The standard frequency for wireless charging of electric vehicles may be lower than 100 kHz, for example, 79 kHz to 90 kHz, specifically, 81 kHz to 90 kHz, more specifically, about 85 kHz, which is a frequency band different from the frequency used in mobile electronic devices such as mobile phones.

[0135] The magnetic permeability of the magnetic unit at a frequency of 85kHz may vary depending on the material. Depending on the specific material, it may be 5 or more, for example, 5 to 150000, and the specific range may be 5 to 300, 500 to 3500, or 10000 to 150000. In addition, the magnetic permeability loss of the magnetic unit at a frequency of 85kHz may vary depending on the material. Depending on the specific material, it may be 0 or more, for example, 0 to 50000, and specifically may be 0 to 1000, 1 to 100, 100 to 1000, or 5000 to 50000.

[0136] As a specific example, when the magnetic unit is a polymer magnetic unit including magnetic powder and a binder resin, its magnetic permeability can be, for example, 5 to 130, 15 to 80 or 10 to 50 at a frequency of 85 kHz, and its magnetic permeability loss can be 0 to 20, 0 to 15 or 0 to 5.

[0137] Physical properties of magnetic units

[0138] The magnetic unit can be elongated at a certain ratio. For example, the elongation of the magnetic unit can be 0.5% or more. Ceramic-based magnetic materials that do not apply polymers are difficult to have elongation properties. Even if a magnetic unit with a larger area is deformed due to impact, it can reduce damage. Specifically, the elongation of the magnetic unit can be 0.5% or more, 1% or more, or 2.5% or more. The upper limit of the elongation is not particularly limited. However, if the elongation is increased by increasing the content of the polymer resin, the inductance and other properties of the magnetic unit may deteriorate. Therefore, the elongation is preferably 10% or less.

[0139] The magnetic unit has a small change rate of characteristics before and after impact, and its change rate of characteristics is significantly better than that of traditional ferrite magnetic sheets. In this specification, the change rate (%) of certain characteristics before and after impact can be calculated by the following formula.

[0140] Characteristic change rate (%) = |Characteristic value before impact - characteristic value after impact| / characteristic value before impact × 100

[0141] For example, when the magnetic unit is freely dropped from a height of 1m, the change rate of the inductance before and after the impact may be less than 5% or 3% or less. More specifically, the change rate of the inductance may be 0% to 3%, 0.001% to 2%, or 0.01% to 1.5%. Within the above range, since the change rate of the inductance before and after the impact is relatively small, the stability of the magnetic unit can be further improved.

[0142] In addition, when the magnetic unit is freely dropped from a height of 1m, the change rate of its Q value (Ls / Rs) before and after the impact can be 0% to 5%, 0.001% to 4%, or 0.01% to 2.5%. Within the above range, since the change rate of the characteristics before and after the impact is small, the stability and impact resistance of the magnetic unit can be further improved.

[0143] In addition, when the magnetic unit is dropped freely from a height of 1m, the change rate of its resistance before and after the impact can be 0% to 2.8%, 0.001% to 1.8%, or 0.1% to 1.0%. Within the above range, the resistance value can be well maintained below a certain level even if it is repeatedly used in an environment of real impact and vibration.

[0144] In addition, when the magnetic unit falls freely from a height of 1m, the change rate of its charging efficiency before and after the impact can be 0% to 6.8%, 0.001% to 5.8%, or 0.01% to 3.4%. Within the above range, even if the large-area magnetic unit is repeatedly impacted and deformed, it can maintain its characteristics more stably.

[0145] Air circulation unit

[0146] The wireless charging device may include an air circulation unit provided between the magnetic unit and the shielding unit as a passage.

[0147] In a representative wireless charging device for electric vehicles, in order to prevent the problem of a sudden drop in charging efficiency due to the generation of a diamagnetic field, the shielding unit is set to be a certain distance away from the magnetic unit. As a result, an air circulation unit can be set in the empty space between the magnetic unit and the shielding unit. Since the air introduced from the outside directly contacts the surface of the magnetic unit and is released to the outside, the heat generated in the magnetic unit can be circulated, thereby improving the heat dissipation characteristics and charging efficiency. In addition, since the air introduced into the air circulation unit can be air supplied by an external air conditioning system, the problem of deterioration of the magnetic unit due to humidity can be solved.

[0148] The air introduced into the air circulation unit may directly contact the surface of the magnetic unit. In addition, the air introduced into the air circulation unit may directly contact the surface of the shielding unit. In addition, the air introduced into the air circulation unit may directly contact the surfaces of the magnetic unit and the shielding unit.

[0149] The temperature inside the air circulation unit may be 5 to 50° C. For example, it may be 10 to 40° C., 10 to 30° C., 20 to 40° C., 10 to 25° C., or 15 to 30° C.

[0150] In addition, the humidity inside the air circulation unit may be 30% to 80%. For example, it may be 30% to 70%, 50% to 60%, 30% to 60%, or 40% to 65%. If the humidity inside the air circulation unit satisfies the above range, not only the heat dissipation characteristics can be improved, but also the problem of deterioration of the magnetic unit that may be caused by high humidity can be minimized.

[0151] Since the wireless charging device according to the embodiment of the present invention includes an air circulation unit in which air supplied by an external air conditioning system directly contacts the surface of the magnetic unit and circulates, the charging efficiency can be improved by 0.1% or more, specifically, 0.2% to 10%, more specifically, 0.5% to 5%, compared to a wireless charging device not including such an air circulation unit. In addition, it can prevent mechanical damage to adjacent circuits that may be caused by heat generated by the magnetic unit and the coil.

[0152] Application of air circulation units

[0153] Figure 2 , 3a to 4a are cross-sectional views of various wireless charging devices (200, 300, 400) including air circulation units, respectively.

[0154] According to the example, Figure 2 As shown, it may further include an inlet pipe (270) connected so that air can be introduced into the air circulation unit (240) and an outlet pipe (280) connected so that air from the air circulation unit (240) can be discharged, both of which are provided on one side or both sides of the air circulation unit (240).

[0155] Specifically, the wireless charging device (200) comprises a coil unit (210), the coil unit (210) comprising a wire; a magnetic unit (220) arranged on one side of the coil unit (210); a shielding unit (230) formed by being spaced apart from the magnetic unit (220); and an air circulation unit (240) arranged between the magnetic unit (220) and the shielding unit (230), wherein air in the air circulation unit (340) directly contacts the surface of the magnetic unit (220), wherein the air circulation unit (340) may further comprise an inlet pipe (270) connected so that air can be introduced into the air circulation unit (240) and an outlet pipe (280) connected so that air from the air circulation unit can be discharged, both of which are arranged on one side or both sides of the air circulation unit (240).

[0156] More specifically, the air circulation unit (240) is in contact with one side of the magnetic unit (220), and the air (245) supplied from the external air conditioning system in the air circulation unit (240) can be introduced into the air circulation unit (240) through the inlet pipe (270), and the introduced air can be circulated in the air circulation unit (240) to release the heat generated in the magnetic unit (220) to the outside through the outlet pipe (280). In this case, the air introduced through the inlet pipe (270) can directly contact the surface of the shielding unit (230). In addition, if the air introduced through the inlet pipe (270) can directly contact the surface of the shielding unit (230) and the surface of the magnetic unit (220), the heat dissipation effect can be maximized. As long as it does not affect the effect of the present invention, the size, shape and material of the inlet pipe (270) and the outlet pipe (280) are not particularly limited.

[0157] Since a typical wireless charging device has a closed structure that prevents humid air or dust from flowing in, it is not conducive to dissipating the heat generated during wireless charging. In particular, if humid air or dust is introduced, it may cause the magnetic unit to deteriorate.

[0158] Then, since the inlet pipe is connected to the external air conditioning system, the air supplied by the air conditioning system passes through the inlet pipe and performs the above-mentioned circulation, the heat generated in the magnetic unit can be released to the outside. Furthermore, since the low-humidity dry air from the air conditioning system can be uniformly circulated on the surface of the magnetic unit, the problem of deterioration of the magnetic unit due to moisture in the prior art can be solved.

[0159] at the same time, Figures 3a to 3b A cross-sectional view of a wireless charging device according to another embodiment and a plan view of an air circulation unit used in the wireless charging device are respectively shown.

[0160] See also Figure 3a and 3b The wireless charging device (300) includes an air circulation unit (340) disposed between the magnetic unit (320) and the shielding unit (330), wherein air in the air circulation unit (340) directly contacts the surface of the magnetic unit (320), wherein the air circulation unit (340) may further include a guide wall (390) formed to allow air to flow.

[0161] If the guide wall (390) is arranged to be in contact with the surface of the magnetic unit (320), the air can be allowed to evenly contact the surface of the magnetic unit (320).

[0162] In addition, the guide wall (390) can be set to correspond to the area where the coil unit (310) is located. Generally speaking, the coil unit has a high electromagnetic wave energy density and may therefore accumulate the most heat to make the temperature the highest. Therefore, the guide wall (390) is set corresponding to the area where the coil unit (310) is located so that air circulates through the guide wall to discharge heat. In addition, the guide wall (390) can be set in the area where the coil unit (310) is located, or in other areas.

[0163] In addition, the guide wall (390) can be fixed by a guide wall fixing member (not shown), and the magnetic unit can include the guide wall fixing member in a portion thereof. As long as the guide wall (390) can be fixed, the size, shape and material of the guide wall member are not particularly limited.

[0164] Since the magnetic unit can be molded into a desired three-dimensional structure by a mold, when the magnetic unit is molded, the guide wall fixing member can be set at a desired position without being restricted by its side or top. The guide wall (390) can be fixed to the wireless charging device by the guide wall fixing member, specifically, so that it will not fall off from the magnetic unit. Alternatively, the guide wall can be fixed to the magnetic unit using an adhesive.

[0165] In addition, the guide wall can be made of a heat-resistant plastic material. Specifically, it can include at least one selected from polypropylene, acrylonitrile-butadiene-styrene copolymer (ABS), polycarbonate, polyamide, polyimide, polybutylene terephthalate, polyphenylene sulfide and polyetheretherketone. The thickness and width of the guide wall are not particularly limited. For example, its thickness can be 1mm to 3mm, 1mm to 2.5mm, 1.5mm to 3mm, 1.5mm to 2.5mm or 2mm3mm, and its width can be 0.1mm to 6mm, 0.1mm to 5mm, 0.1mm to 3mm, 0.5mm to 4mm or 0.3mm to 4mm.

[0166] Based on the circumference of the magnetic unit, the total length of the air flow path of the guide wall can be 25% to 500% of its length, specifically, 50% to 400%, and more specifically, 75% to 300%. If the total length of the air flow path meets the above range, the air can circulate evenly on the surface of the magnetic unit, thereby further improving the heat dissipation characteristics.

[0167] at the same time, Figure 4a is a cross-sectional view of a wireless charging device according to another embodiment of the present invention. Figure 4b Perspective views of various shapes of magnetic units employed for wireless charging devices. Figures 4c to 4e Each of the diagrams is a plan view of a magnetic unit of various shapes used in a wireless charging device for illustrating the interior thereof.

[0168] See also Figures 4a to 4e In the wireless charging device (400), the magnetic unit (420, 420a, 420b, 420c) may further include at least one hole (490) and a cooling channel (495a, 495b, 495c), air is introduced from the air circulation unit (440) through the hole (490), and the cooling channel (495a, 495b, 495c) is provided in the magnetic unit (420, 420a, 420b, 420c) and connected to the hole (490) to circulate the air (445).

[0169] Since the magnetic unit (420, 420a, 420b, 420c) can be molded into a three-dimensional structure by a mold, the hole (490) and the cooling channel (495a, 495b, 495c) can be set inside the magnetic unit when the magnetic unit is molded. In addition, the wireless charging device (400) can further include an inlet pipe (470) arranged on one side of the air circulation unit (440) and connected so that air can be introduced into the air circulation unit (440) and an outlet pipe (480) arranged on one side of the magnetic unit (420) and connected so that air from the cooling channel (495a, 495b, 495c) can be discharged.

[0170] Figure 4b The magnetic unit (420) includes a hole (490) existing inside the magnetic unit (420) and an outlet pipe (480) provided on one side of the magnetic unit (420) and connected to release air. Since the air (445) introduced from the inlet pipe (470) passes through the inside of the magnetic unit (420) via the hole (490), the heat dissipation effect can be maximized.

[0171] also, Figures 4c to 4e Various shapes of cooling channels (495a, 495b, 495c) disposed inside the magnetic units (420a, 420b, 420c) and connected to the holes (490) for circulating air are shown respectively. In addition, the outlet pipe (480) may be connected to the cooling channels (495a, 495b, 495c) disposed inside the magnetic units.

[0172] The shape of the cooling channel is not particularly limited as long as it does not affect the effect of the present invention. For example, it may include a curved channel, a straight channel or a bent channel.

[0173] Specifically, Figure 4c As shown, the cooling channel (495a) can be a curved channel. Figure 4dAs shown, the cooling channel (495a) can be a straight channel. Figure 4e As shown, the cooling channel (495a) can be a curved channel.

[0174] The diameter of the hole (490) may be 0.5 mm to 4.5 mm, specifically, 1 mm to 3 mm, more specifically, 1.5 mm to 2.5 mm.

[0175] In addition, the diameter of the cooling channel (495a, 495b, 495c) can be 0.5mm to 4.5mm, specifically, 1mm to 3mm, more specifically, 1.5mm to 2.5mm. In addition, the diameters of the cooling channel and its holes can be the same or different from each other. If the diameter of the cooling channel exceeds the above range, the charging efficiency may be reduced. If the diameter of the cooling channel is less than the above range, the area where the air introduced from the outside circulates through the cooling channel may be narrowed, thereby possibly reducing the heat dissipation characteristics.

[0176] The total internal volume of the cooling channels (495a, 495b, 495c) may be 1% to 40%, specifically, 3% to 30%, and more specifically, 5% to 20% of the total volume of the magnetic unit.

[0177] The cooling channel is set to the area corresponding to the location of the coil unit, so that the heat of the coil unit that has accumulated a large amount of heat due to the high electromagnetic wave energy density is released to the outside through the cooling channel, thereby maximizing the heat dissipation effect. In addition, the cooling channel can be set in the area where the coil unit is located, or in other areas.

[0178] Microchannel

[0179] like Figure 6 As shown, the wireless charging device (600) according to the embodiment may include a microchannel (695) disposed inside or near the magnetic unit (620). As a result, the heat generated in the magnetic unit (620) can be effectively released through the shielding unit.

[0180] The shape of the microchannel is not particularly limited as long as it is a shape that allows fluid to easily pass through to transfer heat of the magnetic unit to the outside. Figure 7a FIG. 1 is a plan view of a magnetic unit including a microchannel. Figure 7a As shown, the microchannel (695) can be designed to enable the fluid injected into the inlet (670) to circulate over a large area and then be discharged through the outlet (680).

[0181] At the same time, since the main heating area in the magnetic unit is the area corresponding to the coil unit, the microchannel can be set to correspond to the area where the coil is located. In other words, it may be difficult to set the microchannel in the central area of ​​the coil unit where the wire density is low.

[0182] The inner diameter of the microchannel may be 0.1 mm to 5 mm. Within the above range, the magnetic properties per unit volume of the magnetic material may be maintained while further improving the heat dissipation properties through the smooth flow of the fluid. More specifically, the inner diameter of the microchannel may be 0.5 mm to 3 mm, 0.5 mm to 2 mm, or 2 mm to 5 mm.

[0183] like Figure 7a As shown, the microchannel (695) can be arranged inside the magnetic unit (620). In this case, it is advantageous to be able to effectively handle the heat generated in the magnetic unit. The structure of the microchannel arranged inside the magnetic unit can be designed in a variety of ways.

[0184] As an example, a polymer magnetic material can be molded by a mold to have a microchannel therein. In this case, the empty space inside the magnetic unit can be defined as a microchannel.

[0185] As another example, once the polymer magnetic material is molded by a mold to have an internal space for inserting the microchannel, the microchannel can be inserted therein. In this case, the microchannel can be prefabricated using metal or other thermally conductive materials and then inserted into the polymer magnetic material.

[0186] As yet another example, a microchannel may be inserted between several magnetic sheets, and then the magnetic sheets may be stacked to prepare a magnetic sheet laminate for microchannel insertion.

[0187] The total internal volume of the microchannel can be 5% to 70% based on the total volume of the magnetic unit. Within the above range, it can be more conducive to improving the electromagnetic wave shielding performance and heat dissipation characteristics of the magnetic unit at the same time. More specifically, the total internal volume of the microchannel can be 5% to 40%, 20% to 50%, or 40% to 70% based on the total volume of the magnetic unit.

[0188] Or, if Figure 8b As shown, the microchannel (695) can be arranged near the magnetic unit (620). As an example, the microchannel (695) can be arranged between the magnetic unit (620) and the shielding unit (630). Specifically, the microchannel (695) can be formed inside the heat dissipation unit (640), and the heat dissipation unit (640) can be arranged near the magnetic unit (620). For example, the heat dissipation unit (640) can be attached to one side of the magnetic unit (620). Specifically, the heat dissipation unit (640) can be attached to the side of the magnetic unit (620) facing the shielding unit (630).

[0189] The heat dissipation unit may be composed of a heat conductive material. The heat conductive material may include a metal-based, carbon-based, ceramic-based material, etc. In addition, the heat conductive material may be a composite material in which a metal-based, carbon-based or ceramic-based material is dispersed in a binder resin.

[0190] Alternatively, the microchannel may be disposed between the magnetic unit and the coil unit to simultaneously process heat generated in the magnetic unit and the coil unit.

[0191] Coolers and circulation pumps

[0192] The wireless charging device may further include a cooler connected to the micro-channel. Figure 8a and 8b , the wireless charging device (600) as described in the embodiment may further include a cooler (15) connected to the microchannel (695).

[0193] The cooler (15) may be disposed outside the housing (601) of the wireless charging device. The cooler may adopt a method and structure for effectively cooling the fluid. For example, the cooler may cool the fluid by air cooling or water cooling.

[0194] The cooler is connected to the microchannel and has a sealed structure for waterproofing and dustproofing. Figure 8a and 8b As shown, the cooler (15) can be connected to the inlet and outlet of the microchannel (695) through the connecting channel (16).

[0195] A cooling device commonly provided in an electric vehicle may be used as a cooler for the wireless charging device.

[0196] For example, the cooler may include an automobile air conditioner. Fig. 9 As shown, an air conditioner provided inside the mobile tool (1) can be used as a cooler (15), and the air conditioner can be connected to a connecting channel (16) connected to the inlet and outlet of the microchannel of the wireless charging device (600). As a result, heat can be effectively dissipated even without providing a separate cooling device.

[0197] In addition, the wireless charging device may further include a device for generating a fluid flow in the microchannel, such as a circulation pump.

[0198] fluid

[0199] The wireless charging device may further include a cooling fluid that circulates through the microchannel and the cooler. The fluid can transfer the heat generated in the magnetic material to the outside. Specifically, the fluid can transfer the heat generated in the magnetic material to the cooler.

[0200] The fluid may be a gas or a liquid, for example, air, water or other liquid or gaseous fluid used as a refrigerant.

[0201] Specifically, the fluid may be air, water, oil (eg, engine oil), alcohol (eg, ethylene glycol, propylene glycol, antifreeze), or a mixture thereof.

[0202] At 20° C., the thermal conductivity of the fluid may be 0.022 W / m·K to 0.69 W / m·K, for example, 0.022 W / m·K to 0.038 W / m·K, 0.57 W / m·K to 0.69 W / m·K, 0.13 W / m·K to 0.15 W / m·K, or 0.24 W / m·K to 0.69 W / m·K.

[0203] At 20°C, the density of the fluid can be 0.75 kg / m 3 Up to 1100kg / m 3 , for example, 0.75kg / m 3 Up to 1.39kg / m 3 、840kg / m 3 Up to 1000kg / m 3 , 800kg / m 3 Up to 900kg / m 3 or 840kg / m 3 Up to 1100kg / m 3 .

[0204] At 20°C, the heat capacity of the fluid can be 1005 J / kg·K to 4250 J / kg·K, for example, 1005 J / kg·K to 1023 J / kg·K, 4150 J / kg·K to 4250 J / kg·K, 1700 J / kg·K to 2500 J / kg·K, or 2500 J / kg·K to 4250 J / kg·K.

[0205] At 20°C, the thermal diffusivity of the fluid can be 6×10 -8 m 2 / s to 4960×10 -8 m 2 / s, for example, 1570×10 -8 m 2 / s to 4960×10 -8 m 2 / s, 10×10 -8 m 2 / s to 20×10 -8 m 2 / s, 6×10 -8 m 2 / s to 10×10 -8 m 2 / s or 9×10 -8 m 2 / s to 20×10 -8 m 2 / s.

[0206] As a specific example, at 1 atm (standard atmospheric pressure) and 20°C, the fluid may have a thermal conductivity of 0.022 W / m·K to 0.038 W / m·K, a relative humidity of 0.75 kg / m 3 Up to 1.39kg / m 3 density, heat capacity of 1005 J / kg·K to 1023 J / kg·K and 1570×10 -8 m 2 / s to 4960×10 -8 m 2 / s thermal diffusion coefficient.

[0207] As another specific example, at 20°C, the fluid may have a thermal conductivity of 0.57 W / m·K to 0.69 W / m·K, a thermal conductivity of 840 kg / m 3 Up to 1000kg / m 3 density, heat capacity of 4150 J / kg·K to 4250 J / kg·K and 10×10 -8 m 2 / s to 20×10 -8 m 2 / s thermal diffusion coefficient.

[0208] As another specific example, at 20°C, the fluid may have a thermal conductivity of 0.13 W / m·K to 0.15 W / m·K, a relative humidity of 800 kg / m 3 Up to 900kg / m 3 density, heat capacity of 1700 J / kg·K to 2500 J / kg·K and 6×10 -8 m 2 / s to 10×10 -8 m 2 / s thermal diffusion coefficient.

[0209] As another specific example, at 20°C, the fluid may have a thermal conductivity of 0.24 W / m·K to 0.69 W / m·K, a relative humidity of 840 kg / m 3 Up to 1100kg / m 3 density, heat capacity of 2500 J / kg·K to 4250 J / kg·K and 9×10 -8 m 2 / s to 20×10 -8 m 2 / s thermal diffusion coefficient.

[0210] Support unit

[0211] like Figure 6 As shown, the wireless charging device (600) further includes a support unit (660) for supporting the coil unit (610). The material and structure of the support unit can be the material and structure of a conventional support unit for a wireless charging device. The support unit can be a flat plate structure or a structure having a groove conforming to the shape of the coil formed thereon to fix the coil unit.

[0212] shell

[0213] like Figure 8a and 8b As shown, the wireless charging device (600) as described in the embodiment further includes a housing (601) for accommodating the above components.

[0214] The housing enables components such as the coil unit, the shielding unit, and the magnetic unit to be properly arranged and installed. The material and structure of the housing may be the material and structure of a conventional housing for a wireless charging device. It may be properly designed according to the components used therein.

[0215] Partition

[0216] In addition, the wireless charging device according to the embodiment may further include a partition for maintaining a gap between the shielding unit and the magnetic unit. The material and structure of the partition may be the material and structure of a conventional partition used in a wireless charging device.

[0217] Mobile Tools

[0218] The wireless charging device can be advantageously used in mobile tools such as electric vehicles that require large-capacity power transmission between a transmitter and a receiver.

[0219] Fig.10 A mobile tool is shown, specifically, a mobile tool provided with a wireless charging device. Since the mobile tool has a wireless charging device on its lower side, wireless charging can be performed in a parking lot equipped with an electric vehicle wireless charging system.

[0220] See also Fig.10 The mobile tool (1) as described in the embodiment includes the wireless charging device as described in the embodiment as a receiver (21). The wireless charging device can be used as a receiver for wireless charging of the mobile tool (1) and can receive electrical energy from a transmitter (22) for wireless charging.

[0221] As described above, the mobile tool includes the wireless charging device, and the configuration of the wireless charging device is as described above.

[0222] Specifically, the wireless charging device used in the mobile tool includes a coil unit; a shielding unit arranged above the coil unit; a magnetic unit arranged between the coil unit and the shielding unit; and a channel arranged inside or near the magnetic unit, wherein a fluid for cooling is introduced into the channel and contacts the magnetic unit.

[0223] The configuration and characteristics of each component of the wireless charging device employed in the mobile tool are as described above.

[0224] The mobile tool further includes 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 power the drive system of the electric vehicle. The battery can be charged by power transmitted by the wireless charging device or other additional wired charging devices.

[0225] In addition, the mobile tool may further include a signal transmitter for transmitting information related to charging to the transmitter of the wireless charging system. Such information related to charging may be charging efficiency, such as charging speed, charging status, and the like.

Claims

1. A wireless charging device, comprising a coil unit; the coil unit comprising a conductor in the form of a planar coil; a shielding unit disposed on the coil unit; a magnetic unit disposed between the coil unit and the shielding unit; and a channel disposed inside or near the magnetic unit, wherein: A fluid for cooling is introduced into the channel and contacts the magnetic unit; wherein the wireless charging device includes an air circulation unit provided between the magnetic unit and the shielding unit as the passage, and air introduced into the air circulation unit and directly contacting the surface of the magnetic unit and the surface of the shielding unit as the cooling fluid; The wireless charging device includes a microchannel disposed inside the magnetic unit to serve as the channel; and the total internal volume of the microchannel is 5% to 70% based on the total volume of the magnetic unit; The magnetic unit is a polymer magnetic material, which includes a binder resin and magnetic powder dispersed in the binder resin, and the microchannel is arranged to correspond to the area where the coil unit is located.

2. The wireless charging device according to claim 1, wherein: The air introduced into the air circulation unit is supplied by an external air conditioning system.

3. The wireless charging device according to claim 1, further comprising an inlet pipe and an outlet pipe, wherein the inlet pipe is connected to allow air to be introduced into the air circulation unit, and the outlet pipe is connected to exhaust air from the air circulation unit, and the inlet pipe and the outlet pipe are both arranged on one side or both sides of the air circulation unit.

4. The wireless charging device according to claim 1, wherein: The air circulation unit further includes a guide wall formed to allow the air to flow.

5. The wireless charging device according to claim 1, wherein: The magnetic unit further includes at least one hole to introduce air from the air circulation unit, and a cooling passage provided in the magnetic unit and connected to the hole to circulate the air.

6. The wireless charging device according to claim 1, wherein: The temperature inside the air circulation unit is 5° C. to 50° C., and the humidity inside the air circulation unit is 30% to 80%.

7. The wireless charging device according to claim 1, wherein: The inner diameter of the microchannel is 0.1 mm to 0.5 mm.

8. The wireless charging device according to claim 1, wherein: The wireless charging device further includes a cooler connected to the microchannel, a fluid for cooling circulates and flows through the microchannel and the cooler, and the cooler cools the fluid by air cooling or water cooling.

9. A mobile tool, the mobile tool comprising a wireless charging device, wherein the wireless charging device comprises a coil unit; the coil unit comprises a conductor in the form of a planar coil; a shielding unit disposed on the coil unit; a magnetic unit disposed between the coil unit and the shielding unit; and a channel disposed inside or near the magnetic unit, wherein a fluid for cooling is introduced into the channel and contacts the magnetic unit; in, The wireless charging device includes an air circulation unit provided between the magnetic unit and the shielding unit as the passage, and air as the cooling fluid introduced into the air circulation unit and directly contacting the surface of the magnetic unit and the surface of the shielding unit; The wireless charging device includes a microchannel disposed inside the magnetic unit to serve as the channel; and the total internal volume of the microchannel is 5% to 70% based on the total volume of the magnetic unit; The magnetic unit is a polymer magnetic material, which includes a binder resin and magnetic powder dispersed in the binder resin, and the microchannel is arranged to correspond to the area where the coil unit is located.

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