Wireless charging device and mobile tool including the same

Abstract

The wireless charging device according to the embodiment can improve the charging efficiency and heat dissipation characteristics by using a three-dimensional structure in the magnetic part. In detail, by increasing the thickness of the magnetic part near the coil part where the electromagnetic energy is concentrated during wireless charging, and reducing the thickness of the center of the magnetic part where the electromagnetic energy density is relatively low, the wireless charging efficiency can be increased, and the heat generated from the magnetic part can be reduced. Therefore, the wireless charging device can be effectively used for mobile tools that require a large amount of energy transmission between a transmitter and a receiver, such as electric vehicles.

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 have been developing at a very fast pace, and various technologies that fully combine electricity, electronics, communications and semiconductors are continuing to develop. In addition, as electronic devices become more mobile, research on wireless communication and wireless energy transmission technology is being actively carried out in the communication field. In particular, research on a method of wirelessly transmitting energy to electronic devices is being actively carried out.

[0003] Wireless energy transmission refers to the wireless transmission of energy through space without physical contact between the transmitter that provides energy and the receiver that receives energy, using inductive coupling, capacitive coupling or electromagnetic field resonant structures such as antennas. Wireless energy transmission is suitable for portable communication devices, electric vehicles and similar devices that require large-capacity batteries. Because the contacts are not exposed, the risk of short circuits is small, and charging failures in wired methods can be prevented.

[0004] At the same time, as interest in electric vehicles has rapidly increased in recent years, interest in building charging infrastructure has also increased. A variety of charging methods have emerged, such as charging electric vehicles using home chargers, battery replacements, fast charging devices, and wireless charging devices. A new charging business model has also begun to emerge (see the published Korean patent publication No. 2011-0042403). In addition, electric vehicles and charging stations being tested are beginning to stand out in Europe. In Japan, electric vehicles and charging stations are being piloted by vehicle manufacturers and energy companies.

[0005] In a conventional wireless charging device for an electric vehicle, in order to improve the wireless charging efficiency, a magnetic material is installed next to the coil, and a shielding metal plate is installed to separate the magnetic material from a predetermined distance.

[0006] The wireless charging device generates heat during the wireless charging operation due to the resistance of the coil and the magnetic loss of the magnetic material. In particular, the magnetic material in the wireless charging device generates heat with high electromagnetic wave energy density in the part close to the coil. The generated heat can change the magnetic properties of the magnetic material and cause impedance mismatch between the transmitter and the receiver, thereby deteriorating the charging efficiency. As a result, the heat generation is aggravated. However, since this wireless charging device is installed in the lower part of the electric vehicle, a sealing structure is adopted for dustproof, waterproof and shock absorption. Therefore, it is difficult to apply a heat dissipation structure.

[0007] [Prior art documents]

[0008] (Patent Document 1) Korean Patent Publication No. 2011-0042403 Summary of the invention

[0009] Technical issues

[0010] In conventional wireless charging devices, a sintered ferrite sheet as a magnetic material is usually placed between the coil and the metal plate, especially on the side close to the coil. However, the specific gravity of the sintered ferrite sheet is large, and when the distance between the coil and the metal plate becomes closer (for example, 10 mm), there is a problem of a sharp decrease in efficiency. Therefore, in order to maintain the distance between the coil and the metal plate and stably fix the sintered ferrite sheet, a separate structure such as a partition is required. As a result, there is a problem of increased assembly process cost. In addition, during charging, heat is generated from the coil and the sintered ferrite sheet. In particular, the heat generated from the sintered ferrite sheet is difficult to transfer and dissipate to the air or a partition with low thermal conductivity. As a result, the magnetic properties of the sintered ferrite sheet with increased temperature deteriorate, which changes the inductance value of the coil, thereby deteriorating the charging efficiency and causing more serious heat generation.

[0011] To solve this problem, if a sufficiently thick magnetic material is used to fill the gap between the coil and the metal plate, the heat dissipation characteristics can be improved, but the high specific gravity of the magnetic material increases the overall weight, which can lead to problems of reducing the weight of the vehicle and significantly increasing the manufacturing cost. In addition, a method of filling the gap between the magnetic material and the metal plate with a heat dissipation material is also being considered. In this case, due to the conductivity or insulation of the heat dissipation material, the charging efficiency is reduced and the manufacturing cost is increased. If only a part of the gap between the magnetic material and the metal plate is filled with the heat dissipation material, the heat dissipation performance is insufficient.

[0012] As a result of studies conducted by the present inventors, it has been found that if a three-dimensional structure is applied to a magnetic unit employed in a wireless charging device, charging efficiency and heat dissipation characteristics can be improved.

[0013] Therefore, the problem to be solved by the present embodiment is to provide a wireless charging device having improved charging efficiency and heat dissipation characteristics by adopting a magnetic unit with a three-dimensional structure, and a mobile tool including the same.

[0014] Solutions to the problem

[0015] According to one embodiment, a wireless charging device is provided, which includes a coil unit; and a first magnetic unit mounted on the coil unit, wherein the first magnetic unit includes an outer portion corresponding to the portion where the coil unit is mounted; and a central portion surrounded by the outer portion, and the thickness of the outer portion is greater than the thickness of the central portion.

[0016] According to another embodiment, a mobile tool is provided, which includes a wireless charging device, wherein the wireless charging device includes a coil unit; and a first magnetic unit mounted on the coil unit, the first magnetic unit includes an outer portion corresponding to the portion where the coil unit is mounted; and a central portion surrounded by the outer portion, and the thickness of the outer portion is greater than the thickness of the central portion.

[0017] Advantageous Effects of the Invention

[0018] According to the above embodiments, since the magnetic unit used in the wireless charging device adopts a three-dimensional structure, the charging efficiency and heat dissipation characteristics can be improved. Specifically, as the thickness of the magnetic unit near the coil unit where the electromagnetic energy is concentrated during wireless charging increases, and the thickness of the central magnetic unit with a relatively low electromagnetic energy density decreases, the wireless charging efficiency can be increased and the heat generated by the magnetic unit can be reduced.

[0019] In addition, according to a preferred embodiment, due to the combination of two or three different types of magnetic units, the heat generated during the wireless charging process can be effectively dissipated through the distribution of magnetic flux, thereby improving the charging efficiency and heat dissipation characteristics.

[0020] Therefore, the wireless charging device can be advantageously used in mobile tools that require large-capacity energy transfer between a transmitter and a receiver, such as electric vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is an exploded perspective view of a wireless charging device according to an embodiment.

[0022] Figures 2a to 2c Each is a cross-sectional view of a wireless charging device according to various embodiments.

[0023] Figure 3 FIG. 4 is an exploded perspective view of a wireless charging device according to yet another embodiment.

[0024] Figures 4a to 4c Each is a cross-sectional view of a wireless charging device according to various embodiments.

[0025] Figure 5 , 6 7a are respectively an exploded perspective view, a perspective view, and a cross-sectional view of a wireless charging device according to still another embodiment.

[0026] Figures 7b to 8b Each is a cross-sectional view of a wireless charging device according to still another embodiment.

[0027] Fig. 9 An electric vehicle is shown provided with a wireless charging device as a receiver.

[0028] <Description of Reference Numerals>

[0029] 1: Mobile tools (electric vehicles), 10: Wireless charging devices

[0030] 21: Receiver, 22: Transmitter

[0031] 100: support unit, 200: coil unit

[0032] 300: First magnetic unit

[0033] 310: External, 320: Central

[0034] 400: shielding unit, 500: second magnetic unit

[0035] 600: housing, 700: third magnetic unit

[0036] 810, 820: cooling unit DETAILED DESCRIPTION

[0037] In the description of the following embodiments, when it is mentioned that an element is formed “on” or “under” another element, it not only means that an element is directly formed “on” or “under” another element, but also means that an element is indirectly formed on or under another element with other elements interposed therebetween.

[0038] In addition, the terms "up" or "down" regarding each element may refer to the drawings. For convenience of explanation, the sizes of individual elements in the accompanying drawings may be exaggeratedly depicted, and they may be different from actual sizes.

[0039] Throughout the specification, when a part is referred to as “comprising” an element, it should be understood that it can include other elements, rather than excluding other elements, unless specifically stated otherwise.

[0040] Furthermore, unless otherwise indicated, all numbers expressing physical properties, dimensions and the like used herein are to be understood as being modified by the term "about".

[0041] In the present specification, unless otherwise specified, a singular expression is understood to include the singular or plural expression explained in the context.

[0042] Wireless charging device

[0043] According to the embodiment, the wireless charging device includes a coil unit; a first magnetic unit is installed on the coil unit, wherein the first magnetic unit includes an outer portion corresponding to the portion where the coil unit is installed; and a central portion surrounded by the outer portion, and the thickness of the outer portion is greater than the thickness of the central portion.

[0044] In addition, the wireless charging device may further include a shielding unit mounted on the first magnetic unit.

[0045] Reference Figure 1 According to the embodiment, the wireless charging device (10) includes a coil unit (200) including a wire; a shielding unit (400) installed on the coil unit (200); and a first magnetic unit installed between the coil unit (200) and the shielding unit (400), wherein the first magnetic unit (300) may include an outer portion (310) corresponding to the portion where the coil unit (200) is installed, and a central portion (320) surrounded by the outer portion (310), and the thickness of the outer portion (310) may be greater than the thickness of the central portion (320).

[0046] According to the above embodiments, since the magnetic unit used in the wireless charging device adopts a three-dimensional structure, the charging efficiency and heat dissipation characteristics can be improved. Specifically, as the thickness of the magnetic unit near the coil unit where the electromagnetic energy is concentrated during wireless charging increases, and the thickness of the central magnetic unit with a relatively low electromagnetic energy density decreases, the wireless charging efficiency can be increased and the heat generated by the magnetic unit can be reduced.

[0047] In addition, due to the combination of two different types of magnetic units, the heat generated during the wireless charging process can be effectively dissipated through the distribution of magnetic flux, thereby improving the charging efficiency and heat dissipation characteristics.

[0048] Reference Figure 3 According to the embodiment, the wireless charging device (10) includes a coil unit (200) including a wire; a shielding unit (400) installed on the coil unit (200); and a first magnetic unit (300) and a second magnetic unit (500) installed between the coil unit (200) and the shielding unit (400), wherein the first magnetic unit (300) may include an outer portion (310) corresponding to the portion where the coil unit (200) is installed and a central portion (320) surrounded by the outer portion (310), the thickness of the outer portion (310) may be greater than the thickness of the central portion (320), and the magnetic permeability of the second magnetic unit (500) at 85kHz may be higher than the magnetic permeability of the first magnetic unit (300).

[0049] According to the above embodiments, since the magnetic unit used in the wireless charging device adopts a three-dimensional structure and two magnetic units are provided, the charging efficiency and heat dissipation characteristics can be improved together. Specifically, since the second magnetic unit with a higher magnetic permeability than the first magnetic unit is used, the magnetic flux density and heat dissipation can be effectively distributed, thereby increasing the wireless charging efficiency, and the heat generated by the second magnetic unit is dissipated through the shielding unit, thereby enhancing the heat dissipation characteristics.

[0050] In addition, due to the combination of three different types of magnetic materials, the heat generated during the wireless charging process can be effectively dissipated through the distribution of magnetic flux, thereby improving the charging efficiency and heat dissipation characteristics.

[0051] Reference Figure 5 , 6 According to the embodiment, the wireless charging device (10) includes a coil unit (200); a first magnetic unit (300) mounted on the coil unit (200); a second magnetic unit (500) mounted on the first magnetic unit (300) and having a magnetic permeability different from that of the first magnetic unit (300); and a third magnetic unit (700) mounted on the second magnetic unit (500) and having a magnetic permeability different from that of the second magnetic unit (500).

[0052] According to the above embodiments, since three different types of magnetic units are combined, the heat generated during the wireless charging process can be effectively dissipated through the distribution of magnetic flux, thereby improving the charging efficiency and heat dissipation characteristics together. Specifically, the three magnetic units have significantly different magnetic properties, such as magnetic permeability. If two or more magnetic units are used, the magnetic flux density increases in the order of magnitude of the magnetic permeability. Therefore, by combining them, the magnetic flux gathered during wireless charging can be distributed in the desired direction. In addition, during the wireless charging process, the heat generated is proportional to the magnetic flux gathered on the magnetic unit and the loss of magnetic permeability. Therefore, since the three types of magnetic units are properly arranged, the heat can be effectively transferred to the shielding unit and dissipated to the outside. In addition, since the thickness and shape of each magnetic unit are adjusted in consideration of the physical and magnetic properties of the three magnetic units, the impact resistance can be improved and the manufacturing cost can be reduced without compromising the charging efficiency.

[0053] The components of the wireless charging device will be described in detail below.

[0054] Coil unit

[0055] The coil unit may include a conductive wire.

[0056] 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.

[0057] 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 or similar resin.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] Additionally, 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.

[0062] 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 a conductive wire 10 to 30 times.

[0063] In addition, the distance between the planar coil-shaped conductive wires may be 0.1 cm to 1 cm, 0.1 cm to 0.5 cm, or 0.5 cm to 1 cm.

[0064] Within the preferred size and specification range of the planar coil, it can be appropriately used in fields requiring large-capacity energy transmission, such as electric vehicles.

[0065] The coil unit may be arranged to be spaced apart from the magnetic unit (eg, the first magnetic unit) at a predetermined interval. For example, the interval distance between the coil unit and the first magnetic unit may be 0.2 mm or more, 0.5 mm or more, 0.2 mm to 3 mm, or 0.5 mm to 1.2 mm.

[0066] Shielding unit

[0067] The wireless charging device according to the embodiment may further include a shielding unit mounted on the first magnetic unit. In addition, in the case where the wireless charging device further includes a second magnetic unit and a third magnetic unit in addition to the first magnetic unit, the shielding unit may be mounted thereon.

[0068] The shielding unit suppresses electromagnetic interference (EMI) that may be generated by electromagnetic waves leaking to the outside through electromagnetic shielding.

[0069] The shielding unit may be installed to be spaced apart from the coil unit by a predetermined 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.

[0070] In addition, the shielding unit may be arranged to be separated from the magnetic unit, such as the first magnetic unit, by a predetermined interval. For example, the interval distance between the shielding unit and the first magnetic unit may be 3 mm or more, 5 mm or more, 3 mm to 10 mm, or 4 mm to 7 mm.

[0071] The material of the shielding unit may be, for example, metal. Therefore, the shielding unit is 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 be used.

[0072] The shielding unit may 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 may have a thickness of 200 cm 2 or larger, 400cm 2 or larger or 600cm 2 or larger area.

[0073] Alternatively, at least a portion of the first magnetic unit may be in contact with the shielding unit. Figure 2a As shown, the outer portion (310) of the first magnetic unit (300) may be in contact with the shielding unit (400). Specifically, at least a portion of the outer portion of the first magnetic unit may be in contact with the shielding unit. Specifically, one side of the outer portion of the first magnetic unit may be in contact with the shielding unit. In this case, the central portion of the first magnetic unit may not be in contact with the shielding unit.

[0074] Composition of the first magnetic unit

[0075] The first magnetic unit may include magnetic powder and a binder resin.

[0076] Specifically, the first magnetic unit may include a binder resin and magnetic powder dispersed in the binder resin.

[0077] As a result, since the first magnetic powders are bonded to each other by the binder resin, the magnetic unit may have fewer defects over a large area and less damage caused by impact.

[0078] The magnetic powder may be an oxide-based magnetic powder, a metal-based magnetic powder or a mixed powder thereof. For example, the oxide-based magnetic powder may be a ferrite-based powder, specifically, a Ni-Zn-based, Mg-Zn-based or Mn-Zn-based ferrite powder. In addition, the metal-based magnetic powder may be a Fe-Si-Al alloy magnetic powder or a Ni-Fe alloy magnetic powder, more specifically, an Fe-Al-Si powder or a Permalloy powder.

[0079] As an example, the magnetic powder may have a composition of Formula 1 below.

[0080] [Formula 1]

[0081] Fe 1-a-b-c Si a X b Y c

[0082] 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.

[0083] 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.

[0084] The magnetic powder may have an average particle size ranging 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.

[0085] The first magnetic unit may include the magnetic powder in an amount of 10 wt % or more, 50 wt % or more, 70 wt % or more, or 85 wt % or more.

[0086] For example, the first magnetic unit may include the magnetic powder in an amount of 10 wt % to 99 wt %, 10 wt % to 95 wt %, 50 wt % to 95 wt %, 50 wt % to 92 wt %, 70 wt % to 95 wt %, 80 wt % to 95 wt %, or 80 wt % to 90 wt %.

[0087] 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, polyetheretherketone (PEEK) resin, silicone resin, acrylic resin, polyurethane resin, polyester resin, isocyanate resin and epoxy resin, but are not limited thereto.

[0088] 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 binder resin may be a resin comprising at least one functional group or part 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 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).

[0089] The first magnetic unit may include the binder resin in an amount of 5 wt % to 40 wt %, 5 wt % to 20 wt %, 5 wt % to 15 wt %, or 7 wt % to 15 wt %.

[0090] In addition, the first magnetic unit may include, as a binder resin, 6 wt % to 12 wt % of a polyurethane-based resin, 0.5 wt % to 2 wt % of an isocyanate-based curing agent, and 0.3 wt % to 1.5 wt % of an epoxy resin based on the weight thereof.

[0091] Magnetic properties of the first magnetic unit

[0092] The first magnetic unit may have a magnetic characteristic within a specific range around a standard frequency of wireless charging of electric vehicles.

[0093] The standard frequency of wireless charging for electric vehicles may be less than 100 kHz, such as 79 kHz to 90 kHz, specifically 81 kHz to 90 kHz, and more specifically about 85 kHz, which is a frequency band different from the frequency used in mobile electronic devices such as mobile phones.

[0094] The magnetic permeability of the first magnetic unit at a frequency of 85kHz may vary depending on the material. According to the specific material, it may be 5 or more, for example, 5 to 150,000, and may specifically be in the range of 5 to 300, 500 to 3,500, or 10,000 to 150,000. In addition, the magnetic permeability loss of the first magnetic unit at a frequency of 85kHz may vary depending on the material. According to the specific material, it may be 0 or more, for example, 0 to 50,000, and may specifically be 0 to 1,000, 1 to 100, 100 to 1,000, or 5,000 to 50,000.

[0095] As a specific example, when the first magnetic unit is a polymer magnetic material including magnetic powder and a 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.

[0096] Physical characteristics of the first magnetic unit

[0097] The first magnetic unit can be elongated at a specific ratio. For example, the elongation of the first magnetic unit may be 0.5% or greater. In ceramic-based magnetic materials to which polymers are not applied, it is difficult to obtain elongation properties. Even if a large-area magnetic unit is deformed by impact, it can reduce damage. Specifically, the elongation of the first magnetic unit may be 0.5% or greater, 1% or greater, or 2.5% or greater. There is no particular limit on the upper limit of the elongation. However, if the content of the polymer resin is increased to enhance the elongation, characteristics such as the inductance of the magnetic unit may be degraded. Therefore, the elongation is preferably 10% or less.

[0098] The first magnetic unit has a small change rate of characteristics before and after the impact, which is significantly better than those of conventional ferrite magnetic sheets. In this specification, the change rate (%) of certain characteristics before and after the impact can be calculated by the following formula.

[0099] Characteristic change rate (%) = | characteristic value before impact - characteristic value after impact | / characteristic value before impact × 100 For example, when the first magnetic unit is in free fall from a height of 1m, the change rate of its inductance before and after the impact may be less than 5% or 3% or less. More specifically, the inductance change rate may be 0% to 3%, 0.001% to 2%, or 0.01% to 1.5%. Within the above range, the stability of the magnetic unit can be further improved because the inductance change rate before and after the impact is relatively small.

[0100] In addition, when the first magnetic unit is in free fall from a height of 1m, the change rate of its Q factor (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, the stability and impact resistance of the magnetic unit can be further improved due to the small change in characteristics before and after the impact.

[0101] In addition, when the first magnetic unit is free-falling 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, even if it is repeatedly used in an environment with actual impact and vibration, its resistance value can be well maintained below a specific level.

[0102] In addition, when the first magnetic unit is free-falling 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 or deformed, its characteristics can be more stably maintained.

[0103] Three-dimensional structure of the first magnetic unit

[0104] According to the above embodiment, since the first magnetic unit adopts a three-dimensional structure, the charging efficiency and the heat dissipation characteristics can be improved. Figure 1 and 2a, the first magnetic unit (300) may include an outer portion (310) corresponding to the portion where the coil unit (200) is installed; and a central portion (320) surrounded by the outer portion (310), wherein the thickness of the outer portion (310) may be greater than the thickness of the central portion (320). That is, the outer portion of the first magnetic unit may correspond to the portion of the coil unit with a high density of wires. The central portion of the first magnetic unit may correspond to the portion of the coil unit with a low density of wires. In this case, the outer portion and the central portion in the first magnetic unit may be formed integrally with each other.

[0105] As mentioned above, as the thickness of the magnetic unit near the coil where electromagnetic energy is gathered during wireless charging increases, and as the thickness of the central magnetic unit having a relatively low electromagnetic energy density due to the absence of a coil decreases, not only can the electromagnetic waves concentrated around the coil be effectively gathered, thereby improving the charging efficiency, but the distance between the coil and the shielding unit can be firmly maintained without a separate partition, thereby reducing the material and process costs caused by the use of partitions, etc.

[0106] In the first magnetic unit, the outer portion may have a thickness that is 1.5 times or more thicker than that of the central portion. Within the above thickness ratio, the electromagnetic waves concentrated around the coil can be more effectively gathered to improve the charging efficiency, and it is also beneficial to heat generation and weight reduction. Specifically, in the first magnetic unit, the thickness ratio of the outer portion to the central portion may be 2 or more, 3 or more, or 5 or more. In addition, the thickness ratio may be 100 or less, 50 or less, 30 or less, or 10 or less. More specifically, the thickness ratio may be 1.5 to 100, 2 to 50, 3 to 30, or 5 to 10.

[0107] The thickness of the outer portion of the first magnetic unit may be 1 mm or more, 3 mm or more, or 5 mm or more, and 30 mm or less, 20 mm or less, or 11 mm or less. In addition, the thickness of the central portion of the first magnetic unit may be 10 mm or less, 7 mm or less, or 5 mm or less, and 0 mm, 0.1 mm or more, or 1 mm or more. Specifically, the outer portion of the first magnetic unit may have a thickness of 5 mm to 11 mm, and the central portion thereof may have a thickness of 0 mm to 5 mm.

[0108] Reference Figure 2b When the thickness of the central portion (320) of the first magnetic unit (300) is 0, the first magnetic unit (300) may have a hollow shape (e.g., a donut shape) in the central portion (320). In this case, the first magnetic unit may effectively improve charging efficiency even with a smaller area.

[0109] The area and thickness of the first magnetic unit

[0110] The first magnetic unit may have a large area. Specifically, it may have a surface area of ​​200 cm 2 or larger, 400cm 2 or larger or 600cm 2 or larger. In addition, the first magnetic unit may have a 10,000 cm 2 or smaller area.

[0111] The first magnetic unit with a large area can be configured by combining multiple units of magnetic materials. In this case, the area of ​​a single unit of magnetic material can be 60 cm 2 or larger, 90cm 2 or 95cm 2 Up to 900cm 2 .

[0112] Alternatively, the first magnetic unit may have a hollow shape at the center. In this case, it may have an outer area that corresponds to the area of ​​the coil unit.

[0113] The first magnetic unit may be a magnetic block prepared by a mold forming method. For example, the first magnetic unit may be a three-dimensional structure formed 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 form a three-dimensional structure.

[0114] Alternatively, the first magnetic unit may be a magnetic sheet laminate, for example, a laminate in which 20 or more or 50 or more magnetic sheets are laminated.

[0115] Specifically, in the magnetic sheet laminate, one or more magnetic sheets may be further laminated only on the outside of the first magnetic unit. In this case, each magnetic sheet may have a thickness of 80 μm or more or 85 μm to 150 μm. Such a magnetic sheet may be prepared by a conventional sheeting process, such as mixing a magnetic powder and a binder resin to form a slurry, which is then formed into a sheet shape and cured.

[0116] Magnetic properties of the second magnetic unit

[0117] The wireless charging device according to the embodiment may further include a second magnetic unit in addition to the first magnetic unit. As a result, the charging efficiency of the wireless charging device may be improved while the heat dissipation characteristics may also be improved. Specifically, Figure 3 As shown, it may further include a second magnetic unit (500) mounted on the outside (310) of the first magnetic unit (300).

[0118] Specifically, the wireless charging device further includes a second magnetic unit disposed between the first magnetic unit and the shielding unit, wherein at 85 kHz, the magnetic permeability of the second magnetic unit may be higher than the magnetic permeability of the first magnetic unit.

[0119] The second magnetic unit may have a magnetic characteristic within a specific range around a standard frequency for wireless charging of electric vehicles.

[0120] For example, the magnetic permeability of the second magnetic unit at a frequency of 85 kHz may vary depending on the material. According to the specific material, it may be in the range of 5 to 150,000 and specifically may be in the range of 5 to 300, 500 to 3,500, or 10,000 to 150,000. In addition, the magnetic permeability loss of the second magnetic unit at a frequency of 85 kHz may vary depending on the material. According to the specific material, it may be in the range of 0 to 50,000 and specifically may be 0 to 1,000, 1 to 100, 100 to 1,000, or 5,000 to 50,000.

[0121] As a specific example, if the second magnetic unit is a ferrite-based material, it may 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 at a frequency of 85 kHz.

[0122] At 85kHz, the magnetic permeability of the second magnetic unit may be higher than the magnetic permeability of the first magnetic unit. For example, the difference in magnetic permeability between the second magnetic unit and the first magnetic unit at 85kHz may be 100 or more, 500 or more, or 1,000 or more, specifically, 100 to 5,000, 500 to 4,000, or 1,000 to 4,000.

[0123] Specifically, the first magnetic unit may have a magnetic permeability of 5 to 300 at a frequency of 85 kHz, and the second magnetic unit may have a magnetic permeability of 1,000 to 5,000 at a frequency of 85 kHz.

[0124] Although the magnetic flux density increases with the proximity to the coil during wireless charging, if the magnetic material is around the coil unit, the magnetic flux is concentrated on the magnetic material. If one or more magnetic materials are used, the magnetic flux density increases by the order of magnitude of the magnetic permeability of the magnetic material. Therefore, if a second magnetic unit having a higher magnetic permeability than the first magnetic unit is appropriately arranged, the magnetic flux can be effectively distributed.

[0125] In addition, the second magnetic unit may have a horizontal thermal conductivity of 1 W / m·K or more, for example, 1 W / m·K to 30 W / m·K or 10 W / m·K to 20 W / m·K. In addition, the second magnetic unit may have a vertical thermal conductivity of 0.1 W / m·K or more, for example, 0.1 W / m·K to 2 W / m·K or 0.5 W / m·K to 1.5 W / m·K. Specifically, the second magnetic unit may have a horizontal thermal conductivity of 1 W / m·K to 30 W / m·K and a vertical thermal conductivity of 0.1 W / m·K to 2 W / m·K.

[0126] Accordingly, heat generated due to magnetic permeability loss in the second magnetic unit during wireless charging may be released through the shielding unit adjacent to the second magnetic unit.

[0127] Composition and shape of the second magnetic unit

[0128] The second magnetic unit may include an oxide-based magnetic material, a metal-based magnetic material, or a composite material thereof.

[0129] For example, the oxide-based magnetic material may be a ferrite-based magnetic material. Its specific chemical formula may be expressed by MOFe2O3 (wherein M is one or more divalent metal elements, such as Mn, Zn, Cu and Ni). From the perspective of magnetic properties such as magnetic permeability, the ferrite-based material is preferably a sintered material. The ferrite-based sintered material may be prepared in the form of sheets or blocks by mixing raw materials, followed by calcination, crushing, mixing with a binder resin, molding and sintering.

[0130] More specifically, the oxide-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 in a temperature range from room temperature to 100° C. or higher.

[0131] 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 and 0.4 mol% to 2 mol% of NiO as main components and may further include SiO2, CaO, Nb2O5, ZrO2, SnO and the like as additional subsidiary components. Mn-Zn-based ferrite can be prepared in the form of a sheet or block by mixing the main components in a predetermined molar ratio, calcining at a temperature of 800°C to 1,100°C in air for 1 hour to 3 hours, adding the subsidiary components thereto and pulverizing, mixing with an appropriate amount of a binder resin such as polyvinyl alcohol (PVA), compression molding with a press, and sintering for 2 hours or more by raising the temperature to 1200°C to 1300°C. Thereafter, if necessary, it is processed and cut into a desired size using a wire saw or a water jet.

[0132] In addition, the metal-based magnetic material may be a Fe-Si-Al alloy magnetic material or a Ni-Fe alloy magnetic material, more specifically, aluminum silicon iron or permalloy. In addition, the second magnetic unit may include a nanocrystalline magnetic material. For example, it may be a Fe-based nanocrystalline magnetic material. Specifically, it may include 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. If a nanocrystalline magnetic material is applied as the second magnetic unit, the farther it is from the coil unit, the lower the resistance (Rs) even if the inductance (Ls) of the coil is reduced. Therefore, the quality factor (Q factor: Ls / Rs) of the coil increases, which can improve charging efficiency and reduce heat generation.

[0133] The second magnetic unit may include a magnetic material different from the magnetic material of the first magnetic unit. As a specific example, the first magnetic unit may include a Fe-Si-Al based alloy magnetic material, and the second magnetic unit may include a Mn-Zn based ferrite. The combination of these materials is advantageous in that the second magnetic unit has a higher magnetic permeability at 85 kHz than the magnetic permeability of the first magnetic unit.

[0134] The second magnetic unit may have a sheet shape or a block shape.

[0135] The second magnetic unit may have a thickness of 0.5 mm to 5 mm, specifically, 0.5 mm to 3 mm, 0.5 mm to 2 mm, or 1 mm to 2 mm. The thickness of the outer portion of the first magnetic unit may be greater than the thickness of the second magnetic unit. For example, the thickness of the outer portion may be 5 mm to 11 mm, and the thickness of the second magnetic unit may be 0.5 mm to 3 mm.

[0136] The second magnetic unit may have an area that is the same as or different from that of the first magnetic unit.

[0137] For example, the second magnetic unit may have the same large area as the large area of ​​the first magnetic unit. Specifically, the second magnetic unit may have a large area of ​​200 cm 2 or larger, 400cm 2 or larger or 600cm 2 or larger. In addition, the second magnetic unit may have a 10,000 cm 2 Or smaller area. In addition, the second magnetic unit with a large area can be configured by combining magnetic materials of multiple units. In this case, the area of ​​a single unit magnetic material can be 60cm 2 or larger, 90cm 2 or 95cm 2 Up to 900cm 2 .

[0138] Alternatively, the second magnetic unit may have an area smaller than that of the first magnetic unit. For example, if the second magnetic unit is only disposed outside the first magnetic unit, the second magnetic unit may have an area corresponding to the area of ​​the outside. In addition, correspondingly, the second magnetic unit may be disposed at a position corresponding to the coil unit and may have an area corresponding to the area of ​​the coil unit. In this case, even with a smaller area, the second magnetic unit can effectively improve the charging efficiency and heat dissipation characteristics.

[0139] Arrangement of the second magnetic unit

[0140] The second magnetic unit may be disposed on an exterior, a central portion, or at least a portion of the first magnetic unit.

[0141] As an example, the second magnetic unit may be disposed on the outside of the first magnetic unit. As a result, the high magnetic flux density around the coil unit may be effectively dispersed, thereby increasing the charging efficiency compared to the case where the first magnetic unit is used alone.

[0142] Alternatively, the second magnetic unit may be provided on at least a portion of the outer portion and the central portion.

[0143] In addition, the second magnetic unit can be arranged to be coupled with or separated from the first magnetic unit. Figure 4a As shown, the second magnetic unit (500) can be arranged between the shielding unit (400) and the first magnetic unit (300). Compared with the case where the first magnetic unit is used alone, since the second magnetic unit having a higher magnetic permeability than the first magnetic unit is arranged near the shielding unit, the high magnetic flux density around the coil can be effectively dispersed, thereby not only increasing the charging efficiency, but also effectively dissipating the heat concentrated near the coil of the first magnetic unit.

[0144] In this case, at least a portion of the second magnetic unit may be in contact with the shielding unit. As a result, the heat generated in the second magnetic unit can be effectively released through the shielding unit. For example, when the second magnetic unit is in the form of a sheet, one side of the whole is in contact with the shielding unit. Specifically, the second magnetic unit may be attached to a side of the shielding unit facing the first magnetic unit. The second magnetic unit may be attached to one side of the shielding unit by a thermally conductive adhesive, thereby further enhancing the heat dissipation effect. The thermally conductive adhesive may include a thermally conductive material, such as a metal-based, carbon-based or ceramic-based adhesive, for example, an adhesive resin in which thermally conductive particles are dispersed.

[0145] In this case, the second magnetic unit may also be in contact with the first magnetic unit. For example, the second magnetic unit may be attached to the outside of the first magnetic unit.

[0146] Alternatively, the second magnetic unit may be arranged to be spaced a predetermined distance from the first magnetic unit. For example, the spacing distance between the first magnetic unit and the second magnetic unit may be 1 mm or more, 2 mm or more, 1 mm to 10 mm, 2 mm to 7 mm, 3 mm to 5 mm, or 5 mm to 10 mm.

[0147] like Figure 4b As shown, a groove may be provided on a surface of the first magnetic unit (300) facing the shielding unit (400), and the second magnetic unit (500) may be inserted into the groove.

[0148] In this case, since the first magnetic unit can be used as a housing of the second magnetic unit, the second magnetic unit can be fixed without a separate adhesive or structure. In particular, since the first magnetic unit can be molded into a three-dimensional structure by a mold of a polymer type magnetic unit using magnetic powder and an adhesive resin, a groove for inserting the second magnetic unit can be easily formed.

[0149] In this case, at least a portion of the first magnetic unit and the second magnetic unit may be in contact with the shielding unit (400). As a result, heat generated in the first magnetic unit and / or the second magnetic unit may be effectively released through the shielding unit.

[0150] The depth of the groove formed in the first magnetic unit may be the same as or different from the thickness (height) of the second magnetic unit. If the depth of the groove is the same as the thickness of the second magnetic unit, the first magnetic unit and the second magnetic unit may contact the shielding unit at the same time. Alternatively, if the depth of the groove is less than the thickness of the second magnetic unit, only the second magnetic unit may contact the shielding unit. On the other hand, if the depth of the groove is greater than the thickness of the second magnetic unit, only the first magnetic unit may contact the shielding unit.

[0151] like Figure 4c As shown, the second magnetic unit (500) may be arranged to be embedded in the first magnetic unit (300).

[0152] Even in this case, since the first magnetic unit can be used as a shell of the second magnetic unit, the second magnetic unit can be fixed without a separate adhesive or structure. In particular, since the first magnetic unit can be molded into a three-dimensional structure by a mold of a polymer type magnetic unit using magnetic powder and an adhesive resin, a structure for embedding the second magnetic unit can be easily formed.

[0153] In this case, at least a portion of the first magnetic unit may be in contact with the shielding unit. As a result, heat generated in the first magnetic unit may be effectively released through the shielding unit.

[0154] Combination of three types of magnetic units

[0155] The wireless charging device according to the embodiment may further include a third magnetic unit in addition to the first magnetic unit and the second magnetic unit.

[0156] Specifically, the wireless charging device may further include a second magnetic unit mounted on the first magnetic unit and having a magnetic permeability different from that of the first magnetic unit; and a third magnetic unit mounted on the second magnetic unit and having a magnetic permeability different from that of the second magnetic unit.

[0157] In addition, the first magnetic unit, the second magnetic unit, and the third magnetic unit may be disposed between the coil unit and the shielding unit.

[0158] As a specific example, the first magnetic unit may include magnetic powder and a binder resin, the second magnetic unit may include a ferrite-based magnetic material, and the third magnetic unit may include a nanocrystalline magnetic material.

[0159] The sintered ferrite sheet, which is mainly used as a magnetic unit in conventional wireless charging devices, has excellent magnetic properties, but it has high brittleness, lacks deformation resistance, and is heavy. In addition, due to defects such as pores formed during the sintering process, it is easily damaged by thermal shock, forming fragments, thereby causing secondary problems. In order to make up for the shortcomings of this sintered ferrite sheet, a polymer-type magnetic material with improved impact resistance can be used, in which magnetic powder is mixed with a binder resin. However, if the polymer-type magnetic material is used alone, the magnetic permeability is not high, so a large amount of polymer-type magnetic material is required to achieve wireless charging performance above a certain level, making it difficult to miniaturize the device. In addition, when the magnetic flux is concentrated only on the polymer-type magnetic material, the polymer component accumulates heat, which continues to increase in temperature over time. At the same time, the magnetic permeability of the nanocrystalline magnetic material is improved by high-temperature heat treatment of the metal component such as the Fe-based alloy, and its magnetic permeability is significantly higher than that of conventional magnetic materials. However, its magnetic permeability loss is large, the heat generation is serious, and the manufacturing cost is high. If three types of magnetic units with different characteristics are combined as described above, the heat generated during the wireless charging process can be effectively dissipated through the distribution of magnetic flux, thereby improving the charging efficiency and heat dissipation characteristics together.

[0160] The three types of magnetic units have significant differences in magnetic properties such as permeability and permeability loss, depending on the components that constitute them.

[0161] For example, the third magnetic unit may have a higher magnetic permeability than the first magnetic unit and the second magnetic unit at 85kHz, and the second magnetic unit may have a higher magnetic permeability than the first magnetic unit at 85kHz. In addition, the third magnetic unit may have a higher magnetic permeability loss than the first magnetic unit and the second magnetic unit at 85kHz, and the second magnetic unit may have a higher magnetic permeability loss than the first magnetic unit at 85kHz.

[0162] For example, the difference in magnetic permeability at 85 kHz between the second magnetic unit and the first magnetic unit may be 100 or more, 500 or more, or 1000 or more, specifically, 100 to 5,000, 500 to 4,000, or 1,000 to 3,000. In addition, the difference in magnetic permeability at 85 kHz between the third magnetic unit and the second magnetic unit may be 1000 or more, 5000 or more, or 10000 or more, specifically, 1000 to 50000, 5000 to 100000, or 10000 to 150000.

[0163] As a specific example, the first magnetic unit may have a magnetic permeability of 5 to 300 and a magnetic permeability loss of 0 to 30 at 85 kHz, the second magnetic unit may have a magnetic permeability of 1,000 to 5,000 and a magnetic permeability loss of 0 to 300 at 85 kHz, and the third magnetic unit may have a magnetic permeability of 10,000 to 150,000 and a magnetic permeability loss of 1,000 to 10,000 at 85 kHz.

[0164] In addition, since the heat generated during the wireless charging process is proportional to the magnetic flux and permeability loss gathered on the magnetic unit, the heat generated by the three magnetic units during the wireless charging process is also significantly different. For example, during the wireless charging process, specifically, when the coil unit receives wireless energy from the outside, the heat generated in the third magnetic unit may be greater than the heat generated in the first magnetic unit and the heat generated in the second magnetic unit.

[0165] As a specific example, when the coil unit receives wireless energy from the outside, the heat generated in the third magnetic unit may be greater than the heat generated in the second magnetic unit, and the heat generated in the second magnetic unit may be greater than the heat generated in the first magnetic unit.

[0166] As described above, since the three magnetic units have different magnetic properties and heat generation, according to the method of setting and combining them, by using the tendency of the magnetic flux density to increase in the order of the magnetic permeability, the magnetic flux density gathered during the wireless charging process can be distributed in a desired direction. In addition, by utilizing the tendency of the heat generation to increase in proportion to the magnitude of the magnetic flux and magnetic permeability loss, the heat can be effectively dissipated to the outside.

[0167] Reference Figure 7a and 7b , the first magnetic unit (300) among the first magnetic unit (300), the second magnetic unit (500) and the third magnetic unit (700) is arranged closest to the coil unit (200), and the third magnetic unit (700) is arranged closest to the shielding unit (400). In this case, the second magnetic unit can be thermally connected to the shielding unit. As a result, a large amount of heat generated in the second magnetic unit can be easily released to the outside through the shielding unit.

[0168] In addition, since the number of each magnetic unit is adjusted in consideration of the physical and magnetic properties of the three types of magnetic units, impact resistance can be improved and manufacturing costs can be reduced without compromising charging efficiency. For example, the first magnetic unit may have a volume greater than the volume of the second magnetic unit, and the second magnetic unit may have a volume greater than the volume of the third magnetic unit.

[0169] The second magnetic unit may include a ferrite-based magnetic material, and the specific components and manufacturing method are as exemplified above.

[0170] The second magnetic unit may have a sheet shape or a block shape.

[0171] The second magnetic unit may have a thickness of 0.5 mm to 5 mm, specifically, 0.5 mm to 3 mm, 0.5 mm to 2 mm, or 1 mm to 2 mm.

[0172] The second magnetic unit may have an area that is the same as or different from that of the first magnetic unit.

[0173] For example, the second magnetic unit may have the same large area as the large area of ​​the first magnetic unit. Specifically, the second magnetic unit may have a large area of ​​200 cm 2 or larger, 400cm 2 or larger or 600cm 2 or larger. In addition, the second magnetic unit may have a 10,000 cm 2 Or smaller area. In addition, the second magnetic unit with a large area can be configured by combining magnetic materials of multiple units. In this case, the area of ​​a single unit magnetic material can be 60cm 2 or larger, 90cm 2 or 95cm 2 Up to 900cm 2 .

[0174] Alternatively, the second magnetic unit may have an area smaller than that of the first magnetic unit. For example, if the second magnetic unit is only disposed outside the first magnetic unit, the second magnetic unit may have an area corresponding to the area of ​​the outside. In addition, as a result, the second magnetic unit may be disposed at a position corresponding to the coil unit and may have an area corresponding to the area of ​​the coil unit. In this case, even with a smaller area, the second magnetic unit can effectively improve the charging efficiency and heat dissipation characteristics.

[0175] The second magnetic unit may have magnetic properties within a specific range around the standard frequency of wireless charging of electric vehicles. For example, the second magnetic unit may 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 at a frequency of 85 kHz.

[0176] The third magnetic unit may include a nanocrystalline magnetic material. If the nanocrystalline magnetic material is applied as the third magnetic unit, the farther away from the coil unit it is, the lower its resistance (Rs) is, even if the inductance (Ls) of the coil is reduced. Therefore, the quality factor (Q factor: Ls / Rs) of the coil increases, which can improve charging efficiency and reduce heat generation.

[0177] For example, the third magnetic unit may be an iron-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.

[0178] More specifically, the third magnetic unit may be a Fe-Si-B-Cu-Nb-based nanocrystalline magnetic material. In this case, preferably Fe is 70% to 85% by element, Si and B are 10% to 29% by element, and Cu and Nb are 1% to 5% by element (wherein % by element refers to the percentage of the number of specific elements to the number of total 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.

[0179] The nanocrystalline magnetic material is prepared, for example, by a rapid solidification process (RSP) of a melt-spinning Fe-based alloy. It 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.

[0180] If the heat treatment temperature is lower than 300°C, nanocrystals cannot be fully formed, and the desired magnetic permeability cannot be obtained, requiring a longer heat treatment time. If it exceeds 700°C, excessive heat 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, the treatment time is preferably shortened.

[0181] The third magnetic material may have a thickness of 15 μm to 150 μm. At the same time, due to the characteristics of the preparation process, it is difficult to make the nanocrystalline magnetic material thicker. For example, it can be formed into a thin sheet with a thickness of 15 μm to 35 μm. Therefore, a plurality of such thin film sheets can be stacked to form the third magnetic unit. In this case, an adhesive layer such as a tape can be interposed between the thin sheets. In addition, the third magnetic unit can be crushed by a pressure roller or similar means at the end of the manufacturing process to form a plurality of cracks in the thin sheet, so that it can be manufactured to include a plurality of nanocrystalline flakes.

[0182] In addition, as the outer portion of the first magnetic unit is formed to have a thickness different from that of the second magnetic unit and the third magnetic unit, impact resistance can be improved and manufacturing costs can be reduced without compromising charging efficiency. For example, the outer portion of the first magnetic unit may have a thickness greater than the thickness of the second magnetic unit and the thickness of the third magnetic unit, and the second magnetic unit may have a thickness greater than the thickness of the third magnetic unit. As a specific example, the thickness of the outer portion of the first magnetic unit may be 5 mm to 11 mm, the thickness of the second magnetic unit may be 0.5 mm to 3 mm, and the thickness of the third magnetic unit may be 15 μm to 150 μm.

[0183] The third magnetic unit may have magnetic properties within a specific range near the standard frequency of wireless charging of electric vehicles. For example, the third magnetic unit may have a magnetic permeability of 500 to 150,000 and a magnetic permeability loss of 100 to 50,000 at a frequency of 85kHz. For example, when the third 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 85kHz. As another example, when the third 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 85kHz.

[0184] Cooling unit

[0185] The wireless charging device according to the embodiment may further include a heat dissipation unit for efficient heat transfer.

[0186] During the wireless charging process, a large amount of heat is generated in the magnetic unit which is proportional to the concentrated magnetic flux and the loss of magnetic permeability. The heat dissipation unit can effectively transfer the heat generated by the magnetic unit to the outside.

[0187] The heat dissipation unit may have a sheet shape. That is, the heat dissipation unit may be a heat dissipation fin.

[0188] The heat dissipation unit may include a binder resin and a heat dissipation filler dispersed in the binder resin.

[0189] As described above, since the heat dissipation unit includes the polymer component, it can provide adhesion between the shielding unit and the magnetic sheet. In addition, it can prevent the magnetic unit from being damaged due to external impact.

[0190] 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, polyetheretherketone (PEEK) resin, silicone resin, acrylic resin, polyurethane resin, polyester resin, isocyanate resin and epoxy resin, but are not limited thereto.

[0191] 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 can exhibit adhesiveness when cured. More specifically, the binder resin may be a resin including at least one functional group or part 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 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).

[0192] As a specific example, the binder resin may be one or more of a silicone-based resin and an acrylic-based resin.

[0193] In addition, the heat dissipation filler may be one or more of ceramic particles, carbon particles and metal particles. The ceramic particles may include oxides or nitrides of metals. Specifically, they may include silicon dioxide, aluminum oxide, boron nitride, aluminum nitride, magnesium oxide and similar materials. Carbon particles may include graphite, carbon black, carbon nanotubes and similar materials. Metal particles may include copper, silver, iron, nickel and similar metals.

[0194] The heat dissipation filler may be contained in the heat dissipation unit in an amount of 70 wt % to 90 wt %, 70 wt % to 85 wt %, or 75 wt % to 90 wt %.

[0195] The heat dissipation unit may have a thermal conductivity of 0.5 W / m·K to 30 W / m·K, specifically, 2 W / m·K to 5 W / m·K.

[0196] The heat dissipation unit may have a thickness of 0.1 mm to 5 mm, specifically, 0.1 mm to 3 mm or 0.2 mm to 1 mm.

[0197] The heat dissipation unit may have an area that is the same as or different from the area of ​​the first magnetic unit, the second magnetic unit, or the third magnetic unit. For example, if the heat dissipation unit is installed on the outside of the first magnetic unit, the heat dissipation unit may have an area corresponding to the area of ​​the outside. In addition, if the heat dissipation unit is installed between the third magnetic unit and the shielding unit, the heat dissipation unit may have an area corresponding to the area of ​​the third magnetic unit. As a result, even a small-area heat dissipation unit can have excellent heat dissipation characteristics, adhesion, and impact resistance.

[0198] Arrangement of magnetic unit and heat dissipation unit

[0199] The heat dissipation unit may be disposed between the third magnetic unit and the shielding unit.

[0200] The heat dissipation unit can be used as a heat conducting medium to achieve more effective heat transfer between the third magnetic unit and the shielding unit. Specifically, the third magnetic unit can be thermally connected to the shielding unit through the heat dissipation unit.

[0201] To this end, the heat dissipation unit may be in contact with the third magnetic unit and the shielding unit at the same time. More specifically, the heat dissipation unit may adhere to the third magnetic unit and the shielding unit. As a result, the heat generated in the third magnetic unit may be transferred to the shielding unit through the heat dissipation unit to be easily released to the outside.

[0202] In addition, the third magnetic unit may be in contact with the second magnetic unit, and the second magnetic unit may be in contact with the first magnetic unit. In this case, the first magnetic unit, the second magnetic unit, and the third magnetic unit may be thermally connected to each other. To this end, an additional heat dissipation unit may be provided between the first magnetic unit and the second magnetic unit and / or between the second magnetic unit and the third magnetic unit. As a result, the heat generated in the first magnetic unit and / or the second magnetic unit may eventually be more effectively transferred to the shielding unit through the additional heat dissipation unit.

[0203] The second magnetic unit and the third magnetic unit may each be arranged on the outside, the central part, or at least a part thereof of the first magnetic unit. As an example, the second magnetic unit may be arranged on the outside of the first magnetic unit. As a specific example, the second magnetic unit and the third magnetic unit may be arranged on the outside. As a result, the high magnetic flux density around the coil can be effectively dissipated, thereby increasing the charging efficiency compared to the case where the first magnetic unit is used alone. Alternatively, the second magnetic unit and the third magnetic unit may be arranged on at least a part of the outside and the central part.

[0204] In addition, the second magnetic unit may be arranged to be coupled with or separated from the first magnetic unit.

[0205] In addition, the second magnetic unit may be disposed between the shielding unit and the first magnetic unit.

[0206] like Figure 8a As shown, the second magnetic unit (500) and the third magnetic unit (700) can be arranged between the shielding unit (400) and the first magnetic unit (300), and the heat dissipation unit (810) can be in contact with the third magnetic unit (700) and the shielding unit (400) at the same time. Compared with the case where the first magnetic unit is used alone, since the second magnetic unit and the third magnetic unit, each of which has a higher magnetic permeability than the first magnetic unit, are arranged near the shielding unit, the high magnetic flux density around the coil can be effectively dispersed, thereby not only increasing the charging efficiency, but also effectively dissipating the heat concentrated near the coil of the first magnetic unit. In addition, in this article, the heat generated in the second magnetic unit can be effectively transferred to the shielding unit through the heat dissipation unit. For example, when the second magnetic unit is in the form of a sheet, one side thereof can be attached to the shielding unit as a whole through the heat dissipation unit. Specifically, the third magnetic unit can be attached to one side of the shielding unit through the heat dissipation unit.

[0207] In addition, an additional heat dissipation unit (820) may be provided between the second magnetic unit (500) and the third magnetic unit (700). As a result, the heat generated in the first magnetic unit and / or the second magnetic unit may be ultimately transferred to the shielding unit more effectively through the additional heat dissipation unit.

[0208] Furthermore, a groove may be provided on a surface of the first magnetic unit facing the shielding unit, and the second magnetic unit may be inserted into the groove.

[0209] like Figure 8b As shown, the first magnetic unit (300) has a groove on its surface facing the shielding unit (400), the second magnetic unit (500) is inserted into the groove, the third magnetic unit (700) is arranged between the shielding unit (400) and the second magnetic unit (500), and the heat dissipation unit (810) can contact the third magnetic unit (700) and the shielding unit (400) at the same time.

[0210] In this case, since the first magnetic unit can be used as a shell of the second magnetic unit, the second magnetic unit can be fixed without a separate adhesive or structure. In particular, since the first magnetic unit can be molded into a three-dimensional structure by a mold of a polymer magnetic material using magnetic powder and an adhesive resin, it can be easily formed into a groove for inserting the second magnetic unit. In addition, here, the heat generated in the third magnetic unit can be effectively transferred to the shielding unit through the heat dissipation unit.

[0211] The depth of the groove formed in the first magnetic unit may be greater than or less than the thickness (height) of the second magnetic unit.

[0212] Alternatively, the depth of the groove formed in the first magnetic unit may be the same as the thickness (height) of the second magnetic unit. In this case, the third magnetic unit may contact the first magnetic unit and the second magnetic unit.

[0213] In addition, the wireless charging device may further include a heat dissipation unit (820) arranged between the third magnetic unit (700) and the first and second magnetic units (300, 500), wherein the heat dissipation unit (820) is in contact with the first magnetic unit (300), the second magnetic unit (500) and the third magnetic unit (700) at the same time, so that heat can be transferred more efficiently.

[0214] Support unit

[0215] like Figure 5 As shown, the wireless charging device (10) may further include a support unit (100) for supporting the coil unit (200). The material and structure of the support unit may be the material and structure 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 conforming to the shape of the coil is formed to fix the coil unit.

[0216] shell

[0217] As shown in Figures 5, 6 and 7a, the wireless charging device (10) according to the embodiment may further include a housing (600) for accommodating the above components.

[0218] The housing allows components such as the coil unit, the shielding unit, and the magnetic unit to be properly installed and assembled. The material and structure of the housing may be the material and structure of a conventional housing used in a wireless charging device. It may be appropriately designed according to the components used therein.

[0219] Partition

[0220] In addition, the wireless charging device according to the embodiment may further include a partition for ensuring 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.

[0221] Mobile Tools

[0222] Wireless charging devices can be advantageously used in mobile tools that require large-capacity energy transfer between a transmitter and a receiver, such as electric vehicles.

[0223] Fig. 9 An electric vehicle is shown, specifically, an electric vehicle provided with a wireless charging device. Since the wireless charging device is provided on its lower side, it can be wirelessly charged in a parking lot equipped with a wireless charging system for electric vehicles.

[0224] refer to Fig. 9 According to an embodiment, a mobile tool (1) includes a wireless charging device according to an 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 energy from a transmitter (22) for wireless charging.

[0225] As described above, the mobile tool includes the wireless charging device, and the wireless charging device has the configuration described above.

[0226] Specifically, the wireless charging device used by the mobile tool includes a coil unit; a first magnetic unit installed on the coil unit, wherein the first magnetic unit includes an outer portion corresponding to the part where the coil unit is installed; and a central portion surrounded by the outer portion, and the thickness of the outer portion is greater than the thickness of the central portion.

[0227] The configuration and characteristics of the various components of the wireless charging device used in the mobile tool are as described above.

[0228] The mobile tool may further include a battery for receiving energy from the wireless charging device. The wireless charging device may wirelessly receive energy and transmit it to the battery, and the battery may power the drive system of the electric vehicle. The battery may be charged by energy transmitted from the wireless charging device or other additional wired charging devices.

[0229] In addition, the mobile tool may further include a signal transmitter for transmitting information about charging to the transmitter of the wireless charging system. The information about such charging may be charging efficiency, such as charging speed, charging state, and the like.

Claims

1. A wireless charging device, comprising a coil unit; and a first magnetic unit mounted on the coil unit, wherein the first magnetic unit comprises an outer portion corresponding to the portion where the coil unit is mounted; and a central portion surrounded by the outer portion, and the thickness of the outer portion is greater than the thickness of the central portion; The outer portion has a thickness 1.5 times or more thicker than the thickness of the central portion; The thickness of the central portion is 0.1 mm or more; The wireless charging device further includes a shielding unit mounted on the first magnetic unit; The wireless charging device further includes a second magnetic unit disposed between the coil unit and the shielding unit, wherein: The thickness of the outer portion of the first magnetic unit is greater than the thickness of the second magnetic unit, and the magnetic permeability of the second magnetic unit at 85 kHz is higher than the magnetic permeability of the first magnetic unit; Wherein, the difference in magnetic permeability between the second magnetic unit and the first magnetic unit at 85 kHz is 500 or more.

2. The wireless charging device according to claim 1, wherein: The first magnetic unit includes a binder resin and a magnetic powder dispersed in the binder resin.

3. The wireless charging device according to claim 1, wherein: The first magnetic unit is formed into a three-dimensional structure by a mold.

4. The wireless charging device according to claim 1, wherein: At least a portion of the outer portion of the first magnetic unit is in contact with the shielding unit.

5. The wireless charging device according to claim 1, wherein: The first magnetic unit has a magnetic permeability of 5 to 300 at a frequency of 85 kHz, and the second magnetic unit has a magnetic permeability of 1000 to 5000 at a frequency of 85 kHz.

6. The wireless charging device according to claim 1, wherein: The second magnetic unit is disposed on the exterior of the first magnetic unit.

7. The wireless charging device according to claim 1, wherein: The second magnetic unit is disposed between the shielding unit and the first magnetic unit.

8. The wireless charging device according to claim 1, wherein: A groove is provided on a surface of the first magnetic unit facing the shielding unit, and the second magnetic unit is inserted into the groove.

9. The wireless charging device according to claim 1, wherein: The second magnetic unit is mounted on the first magnetic unit; the wireless charging device further includes a third magnetic unit mounted on the second magnetic unit and having a magnetic permeability different from that of the second magnetic unit.

10. The wireless charging device according to claim 9, wherein: The first magnetic unit includes magnetic powder and a binder resin, the second magnetic unit includes a ferrite-based magnetic material, and the third magnetic unit includes a nanocrystalline magnetic material.

11. The wireless charging device according to claim 9, wherein: The magnetic permeability of the third magnetic unit at 85 kHz is higher than the magnetic permeabilities of the first magnetic unit and the second magnetic unit.

12. The wireless charging device according to claim 9, wherein: The third magnetic unit is thermally connected to the shielding unit.

13. A mobile tool, comprising a wireless charging device, wherein the wireless charging device comprises a coil unit, and a first magnetic unit mounted on the coil unit; the first magnetic unit comprises an outer portion corresponding to the portion where the coil unit is mounted; and a central portion surrounded by the outer portion, and the thickness of the outer portion is greater than the thickness of the central portion; The outer portion has a thickness 1.5 times or more thicker than the thickness of the central portion; The thickness of the central portion is 0.1 mm or more; The wireless charging device further includes a shielding unit mounted on the first magnetic unit; The wireless charging device further includes a second magnetic unit disposed between the coil unit and the shielding unit, wherein: The thickness of the outer portion of the first magnetic unit is greater than the thickness of the second magnetic unit, and the magnetic permeability of the second magnetic unit at 85 kHz is higher than the magnetic permeability of the first magnetic unit; Wherein, the difference in magnetic permeability between the second magnetic unit and the first magnetic unit at 85 kHz is 500 or more.

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