Wireless charging device and vehicle including same

Abstract

The wireless charging device according to one embodiment has excellent high-temperature stability, with an inductance deviation of 0 or greater at 80°C and a magnetic permeability change rate (ΔP1) of 0 / °C or greater, and can maintain excellent charging efficiency even at high temperatures. Therefore, the wireless charging device can be useful in vehicles such as electric vehicles that require large-capacity power transmission between a transmitter and a receiver.

Description

[Technical field]

[0001] The embodiment relates to a wireless charging device and a vehicle including the same. More specifically, the embodiment relates to a wireless charging device having excellent high temperature stability and therefore excellent charging efficiency even at high temperatures, and a vehicle including the same. [Background technology]

[0002] Recently, the information and communications field has been developing at a very fast pace, and various technologies that comprehensively combine electricity, electronics, communications, semiconductors, etc. are being continuously developed. In addition, as the trend for electronic devices to become more mobile increases, research on wireless communication and wireless power transmission technologies is being actively conducted in the communications field. In particular, research on methods for wirelessly transmitting power to electronic devices is being actively conducted.

[0003] The wireless power transmission wirelessly transmits power through space using inductive coupling, capacitive coupling, or an electromagnetic resonance structure such as an antenna without physical contact between a transmitter that supplies power and a receiver that receives the power. The wireless power transmission is suitable for portable communication devices and electric vehicles that require large-capacity batteries, and since the contacts are not exposed, there is almost no risk of leakage and the like, and it can prevent the charging failure phenomenon that occurs with wired methods.

[0004] Meanwhile, as interest in electric vehicles has recently surged, so has interest in building charging infrastructure. A variety of charging methods have already emerged, including charging electric vehicles using home chargers, battery swapping, rapid charging devices, and wireless charging devices, and new charging business models are also beginning to emerge (see Patent Document 1). In Europe, electric vehicles and charging stations undergoing trial operation are becoming more noticeable, while in Japan, automakers and power companies are taking the lead in experimentally operating electric vehicles and charging stations.

[0005] In the wireless charging device, heat is generated due to the resistance of the coil unit and the magnetic loss of the magnetic unit during wireless charging. In particular, the magnetic unit in the wireless charging device inevitably generates high temperature heat during wireless charging, and the generated heat may change the magnetic properties of the magnetic unit, causing safety issues such as damage to the wireless charging device and the possibility of destruction of the power conversion circuit, resulting in restrictions on usability or reducing charging efficiency. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Korean Patent Publication No. 2011-0042403 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been devised to solve the problems of the prior art. The technical problem to be solved by the present invention is to provide a wireless charging device that has high charging efficiency even at high temperatures by providing high temperature stability.

[0008] Another technical problem to be solved by the present invention is to provide a means of transportation including the wireless charging device. [Means for solving the problem]

[0009] According to one embodiment, a wireless charging device is provided that includes a coil portion and a magnetic portion arranged on the coil portion, and has an inductance deviation (ID1) at 80°C, represented by the following equation 1, of 0 (zero) or greater.

[0010] JPEG0007625694000001.jpg56164

[0011] According to another embodiment, a wireless charging device is provided that includes a coil portion and a magnetic portion arranged on the coil portion, wherein the magnetic portion has a first permeability change rate (ΔP1) represented by the following equation 6 that is greater than or equal to 0 / °C.

[0012] JPEG0007625694000002.jpg47164

[0013] According to another embodiment, there is provided a means of transportation including a wireless charging device, the wireless charging device including a coil unit and a magnetic unit arranged on the coil unit, wherein the wireless charging device has an inductance deviation (ID1) at 80°C expressed by the following Equation 1 that is 0 or greater, or the magnetic unit has a first permeability change rate (ΔP1) expressed by the following Equation 6 that is 0 / °C or greater, or both.

[0014] JPEG0007625694000003.jpg107164 Effect of the Invention

[0015] According to the above embodiment, the wireless charging device of the present invention has an inductance deviation of 0 or more at 80° C., thereby improving high temperature stability and providing a wireless charging device with excellent charging efficiency even at high temperatures.

[0016] In addition, in the wireless charging device, since the magnetic part has a rate of change in magnetic permeability of 0 / ° C. or more, the heat resistance characteristics are improved, and the charging efficiency can be further improved.

[0017] Therefore, the wireless charging device can be usefully used not only in electric vehicles that require large-capacity power transmission between a transmitter and a receiver, but also in various personal transportation means such as electric motorcycles, electric kickboards, electric scooters, electric wheelchairs, and electric bicycles. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 shows an exploded perspective view of a wireless charging device according to one implementation. [Diagram 2] FIG. 2 shows a perspective view of the wireless charging device according to one implementation. [Figure 3a] FIG. 3a shows a cross-sectional view of the wireless charging device taken along line AA' in FIG. [Figure 3b] FIG. 3b shows a cross-sectional view of a wireless charging device according to yet another implementation. [Figure 4] FIG. 4 is a graph showing charging efficiency as a function of wireless charging time in the wireless charging devices in Example 1 and Comparative Example 1. In FIG. [Diagram 5] FIG. 5 is a graph showing the heat temperature of the magnetic portion versus the wireless charging time in the wireless charging devices in Example 1 and Comparative Example 1. [Figure 6] FIG. 6 is a graph showing the rate of inductance change at 150° C. depending on the wireless charging time of the wireless charging devices in Example 1 and Comparative Example 1. [Figure 7] FIG. 7 is a graph showing the rate of inductance change due to a temperature rise from −40° C. to 120° C. in the wireless charging devices in Example 1 and Comparative Example 1. In FIG. [Figure 8] FIG. 8 is a graph showing the magnetic permeability of the polymer-type magnetic part according to a temperature rise from −40° C. to 120° C. in the wireless charging devices in Example 1 and Comparative Example 1. In FIG. [Figure 9] FIG. 9 illustrates a process for forming the magnetic portion by molding according to one implementation. [Figure 10] FIG. 10 shows a transportation means (electric vehicle) equipped with a wireless charging device according to one implementation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments for realizing the concept of the present invention will be described in detail with reference to the drawings.

[0020] In the description of the present invention, if a specific description of related publicly known configurations or functions is determined to make the gist of the present invention unclear, the detailed description will be omitted.

[0021] In addition, in the accompanying drawings, some components are exaggerated, omitted, or illustrated diagrammatically, and the size of each component does not completely reflect the actual size.

[0022] The terms used in this specification are merely used to describe specific embodiments and are not intended to limit the present invention. A singular expression includes a plural expression unless the context clearly indicates otherwise. In this specification, like numbers refer to like elements.

[0023] In this specification, when a component is described as being formed above or below another component, this includes all cases in which the component is directly formed above or below the other component, or indirectly formed via still other components.

[0024] In addition, the reference for the top / bottom of each component will be described based on the drawings. The size and thickness of each component in the drawings may be exaggerated for the purpose of explanation and may differ from the actual size.

[0025] Additionally, the meaning of "comprising" as used herein embodies certain properties, regions, integers, steps, operations, elements, components and / or components, and does not exclude the presence or addition of other certain properties, regions, integers, steps, operations, elements, components and / or groups.

[0026] In addition, all numerical ranges indicating physical properties, dimensions, and the like of components described in this specification should be understood to be modified in all cases by the term "about" unless otherwise specified.

[0027] In this specification, the singular expressions are to be construed as including the singular or plural as the context requires, unless otherwise specified.

[0028] (wireless charging device) A wireless charging device according to an embodiment of the present invention includes a coil unit and a magnetic unit disposed on the coil unit, and has an inductance deviation (ID1) at 80° C., expressed by the following Equation 1, of 0 or more.

[0029] JPEG0007625694000004.jpg56164

[0030] The wireless charging device has an inductance deviation of 0 or more at 80° C., and thus has improved high-temperature stability and can maintain excellent charging efficiency even at high temperatures.

[0031] Specifically, the inductance deviation (ID1) of the wireless charging device at 80°C is the difference (I80~I25) between the inductance (I80) of the wireless charging device measured at a temperature of 80°C and the inductance (I25) of the wireless charging device measured at a temperature of 25°C, divided by the inductance of the wireless charging device measured at a temperature of 25°C, and the inductance deviation ID1 of the wireless charging device has a value of 0 or positive (+).

[0032] According to an embodiment of the present invention, the inductance deviation (ID1) of the wireless charging device at 80°C is greater than or equal to 0, thereby improving charging efficiency, or maintaining excellent charging efficiency or minimizing the degree of decrease in efficiency even when the temperature increases.

[0033] Specifically, the inductance deviation (ID1) of the wireless charging device at 80°C may be 0 or more, more than 0, 0.0001 or more, 0.0005 or more, 0.001 or more, 0.005 or more, 0.008 or more, or 0.01 or more. The inductance deviation (ID1) of the wireless charging device at 80°C may be 1 or less, less than 1, 0.9 or less, 0.8 or less, 0.7 or less, 0.6 or less, 0.5 or less, 0.4 or less, 0.3 or less, 0.2 or less, 0.1 or less, 0.09 or less, or 0.08 or less. The inductance deviation (ID1) of the wireless charging device at 80°C may be, for example, 0 or more to 1 or less, more than 0 to less than 1, 0.0001 or more to 0.9 or less, 0.0005 or more to 0.8 or less, or 0.001 or more to 0.7 or less.

[0034] If the inductance deviation (ID1) at 80° C. of the wireless charging device has a negative (−) value, the charging efficiency decreases, and in particular, if the high temperature stability decreases and the temperature increases, the charging efficiency may decrease rapidly.

[0035] In a wireless charging device according to an embodiment of the present invention, the inductance deviation (ID2) at 60° C., represented by the following Equation 2, may be 0 or more.

[0036] JPEG0007625694000005.jpg64164

[0037] Specifically, the inductance deviation (ID2) of the wireless charging device at 60°C may be 0 or more, more than 0, 0.0001 or more, 0.0005 or more, 0.001 or more, 0.005 or more, 0.008 or more, or 0.01 or more. The inductance deviation (ID2) of the wireless charging device at 60°C may be 1 or less, less than 1, 0.9 or less, 0.8 or less, 0.7 or less, 0.6 or less, 0.5 or less, 0.4 or less, 0.3 or less, 0.2 or less, 0.1 or less, 0.09 or less, or 0.08 or less. The inductance deviation (ID2) of the wireless charging device at 60°C may be, for example, 0 or more to 1 or less, more than 0 to less than 1, 0.0001 or more to 0.9 or less, 0.0005 or more to 0.8 or less, 0.001 or more to 0.7 or less, or 0.001 or more to 0.6 or less.

[0038] According to an embodiment of the present invention, the inductance deviation (ID2) of the wireless charging device at 60°C is greater than or equal to 0, and therefore the wireless charging device has excellent high temperature stability and can maintain excellent charging efficiency or minimize the degree of decrease in charging efficiency even when the temperature increases.

[0039] In a wireless charging device according to an embodiment of the present invention, an inductance deviation (ID3) at 100° C., represented by the following Equation 3, may be 0 or more.

[0040] JPEG0007625694000006.jpg56164

[0041] Specifically, the inductance deviation (ID3) of the wireless charging device at 100°C may be 0 or more, more than 0, 0.0001 or more, 0.0005 or more, 0.001 or more, 0.005 or more, 0.008 or more, or 0.01 or more. The inductance deviation (ID3) of the wireless charging device at 100°C may be 1 or less, less than 1, 0.9 or less, 0.8 or less, 0.7 or less, 0.6 or less, 0.5 or less, 0.4 or less, 0.3 or less, 0.2 or less, 0.1 or less, 0.09 or less, or 0.08 or less. The inductance deviation (ID3) of the wireless charging device at 100°C may be, for example, 0 or more to 1 or less, more than 0 to less than 1, 0.0001 or more to 0.9 or less, 0.0005 or more to 0.8 or less, 0.001 or more to 0.5 or less, or 0.001 or more to 0.1 or less.

[0042] According to an embodiment of the present invention, the inductance deviation (ID3) of the wireless charging device at 100°C is greater than or equal to 0, and therefore the wireless charging device has excellent high temperature stability and can maintain excellent charging efficiency or minimize the degree of decrease in charging efficiency even when the temperature increases.

[0043] In a wireless charging device according to an embodiment of the present invention, the inductance deviation (ID4) at 40° C., represented by the following Equation 5, may be 0 or more.

[0044] JPEG0007625694000007.jpg56164

[0045] Specifically, the inductance deviation (ID4) of the wireless charging device at 40° C. may be 0 or more, more than 0, 0.0001 or more, 0.0005 or more, 0.001 or more, 0.005 or more, 0.008 or more, or 0.01 or more. Also, the inductance deviation (ID4) of the wireless charging device at 40° C. may be 1 or less, less than 1, 0.9 or less, 0.8 or less, 0.7 or less, 0.6 or less, 0.5 or less, 0.4 or less, 0.3 or less, 0.2 or less, 0.1 or less, 0.09 or less, 0.08 or less, or 0.05 or less. The inductance deviation (ID4) of the wireless charging device at 40° C. can be, for example, 0 to 1, greater than 0 to less than 1, 0.0001 to 0.9, 0.0005 to 0.8, 0.001 to 0.7, 0.001 to 0.5, or 0.001 to 0.4.

[0046] According to an embodiment of the present invention, the inductance deviation (ID4) of the wireless charging device at 40°C is greater than or equal to 0, and therefore the wireless charging device has excellent high temperature stability and can maintain excellent charging efficiency or minimize the degree of decrease in charging efficiency even when the temperature increases.

[0047] In a wireless charging device according to an embodiment of the present invention, the inductance change rate (ΔID) represented by the following Equation 4 may be greater than 0 / °C.

[0048] JPEG0007625694000008.jpg39127

[0049] The inductance change rate (ΔID) is the difference between the inductance deviation (ID3) at 100°C and the inductance deviation (ID4) at 40°C divided by 20°C.

[0050] Specifically, the inductance change rate (ΔID) of the wireless charging device may be 0.00001 / ° C. or more, 0.00002 / ° C. or more, 0.00003 / ° C. or more, 0.00004 / ° C. or more, 0.00005 / ° C. or more, or 0.00006 / ° C. or more. Also, the inductance change rate (ΔID) of the wireless charging device may be 0.5 / ° C. or less, 0.4 / ° C. or less, 0.3 / ° C. or less, 0.2 / ° C. or less, 0.1 / ° C. or less, 0.05 / ° C. or less, 0.02 / ° C. or less, 0.01 / ° C. or less, 0.005 / ° C. or less, or 0.001 / ° C. or less. The inductance change rate (△ID) of the wireless charging device can be, for example, from more than 0 / °C to less than 0.5 / °C, from more than 0 / °C to less than 0.4 / °C, from 0.00001 / °C to less than 0.3 / °C, from 0.00002 / °C to less than 0.02 / °C, from 0.00003 / °C to less than 0.005 / °C, or from 0.00004 / °C to less than 0.001 / °C.

[0051] According to an embodiment of the present invention, the inductance change rate (△ID) of the wireless charging device is greater than 0 / ℃, and therefore has excellent high temperature stability, and can maintain excellent charging efficiency or minimize the degree of decrease in charging efficiency even when the temperature increases.

[0052] The inductance means the property of a conductor that prevents changes in current, and means the ratio of the back electromotive force generated by electromagnetic induction in response to changes in the flowing current.

[0053] The factors that affect the inductance are various and may vary, such as the material of the magnetic part, the magnetic permeability, the number of turns of the coil, the core, and the size and cross-sectional area of ​​the magnetic part, etc. In particular, the inductance may be determined by the material or properties of the magnetic part.

[0054] The inductance, inductance deviation, or inductance change rate according to the embodiment of the present invention is the inductance, inductance deviation, or inductance change rate of a wireless charging device, and specifically may be the inductance, inductance deviation, or inductance change rate of a wireless charging pad formed by sequentially stacking a coil part, a magnetic part, a spacer (thickness 5T), and a shield part. The inductance has an inductance of, for example, 30 μH, and is measured using an LCR meter (IM3536 device of Hioki E.E. Corporation) using a coil diameter of 5 mm, 1000 square planar coils, a magnetic part with a volume of 320 mm×320 mm×5 mm, and an aluminum (Al) shield part with a volume of 350 mm×350 mm×2 mm. After connecting the device to the coil part, the setting value of the LCR meter is set to 85 kHz, and then the inductance Ls is measured, and the inductance deviation and inductance change rate can be measured using the inductance Ls.

[0055] The wireless charging device may have an inductance at 20° C. of 30 μH to 50 μH, 35 μH to 45 μH, 38 μH to 45 μH, 39 μH to 43 μH, 40.07 μH to 43 μH, or 40.09 μH to 43 μH.

[0056] The wireless charging device may have an inductance at 25° C. of 35 μH to 50 μH, 38 μH to 50 μH, 40 μH to 50 μH, 40 μH to 45 μH, or 40 μH to 43 μH.

[0057] The wireless charging device may have an inductance at 40° C. of 39 μH to 52 μH, 39 μH to 50 μH, 40 μH to 50 μH, 42 μH to 50 μH, or 42 μH to 45 μH.

[0058] The wireless charging device may have an inductance at 60° C. of 37 μH to 55 μH, 39 μH to 52 μH, 40 μH to 50 μH, 42 μH to 50 μH, or 42 μH to 48 μH.

[0059] The wireless charging device may have an inductance at 80° C. of 35 μH to 55 μH, 38 μH to 52 μH, 40 μH to 50 μH, 42 μH to 50 μH, or 42 μH to 48 μH.

[0060] The wireless charging device may have an inductance at 100° C. of 32 μH to 55 μH, 35 μH to 52 μH, 38 μH to 50 μH, 40 μH to 50 μH, or 42 μH to 48 μH.

[0061] The wireless charging device may have an inductance at 120° C. of 30 μH to 52 μH, 35 μH to 52 μH, 38 μH to 50 μH, 40 μH to 50 μH, or 40 μH to 48 μH.

[0062] When the inductance satisfies the above range at each temperature, the wireless charging device can satisfy the physical property range of the wireless charging device according to the embodiment of the present invention, thereby minimizing deformation and damage of the magnetic part at high temperatures and improving charging efficiency.In addition, since high temperature stability can be provided, excellent charging efficiency can be maintained or the degree of decrease in charging efficiency can be minimized even when the temperature increases.

[0063] Moreover, the wireless charging device can satisfy the formulas 1 to 5 by appropriately adjusting the inductance at each temperature.

[0064] Meanwhile, the wireless charging device may have an inductance change rate of 10% or less when the temperature rises from 25° C. to 120° C. According to the embodiment, if the inductance change rate is 10% or less even when the temperature rises from 25° C. to 120° C., the wireless charging device has excellent high temperature stability and can maintain excellent charging efficiency even at high temperatures.

[0065] Specifically, when the temperature rises from 25° C. to 120° C., the inductance change rate may be, for example, 9% or less, for example, 8% or less, for example, 7% or less, for example, 6% or less, for example, 4% or less, for example, 3.9% or less, for example, 3.8% or less, for example, 3.7% or less, for example, 3% or less, for example, 2% or less, for example, 1% or less. The lower the inductance change rate, the more improved the heat resistance characteristics and magnetic characteristics can be.

[0066] In general, inductance tends to decrease rapidly as temperature increases. In contrast, the wireless charging device according to the embodiment of the present invention is characterized by a low inductance change rate of 10% or less as the temperature rises. In other words, the wireless charging device having the above inductance characteristics can minimize deformation and damage of the magnetic part at high temperatures and provide high temperature stability, so that excellent charging efficiency can be achieved even when the temperature rises.

[0067] Meanwhile, a wireless charging device according to another embodiment of the present invention includes a coil unit and a magnetic unit arranged on the coil unit, and the magnetic unit has a first permeability change rate (ΔP1) represented by the following Equation 6 that is greater than or equal to 0 / °C.

[0068] JPEG0007625694000009.jpg48164

[0069] Specifically, in the magnetic portion, the first permeability change rate (ΔP1) is the difference between the permeability of the magnetic portion measured at a temperature of 20°C and the permeability of the magnetic portion measured at a temperature of 0°C divided by 20°C.

[0070] Specifically, the first rate of change in magnetic permeability (ΔP1) may be 0 / ° C. or more, more than 0 / ° C., 0.0001 / ° C. or more, 0.0005 / ° C. or more, 0.001 / ° C. or more, 0.005 / ° C. or more, 0.008 / ° C. or more, 0.01 / ° C. or more, or 0.1 / ° C. or more. In addition, the first rate of change in magnetic permeability (ΔP1) may be 3 / ° C. or less, 2 / ° C. or less, 1 / ° C. or less, 0.9 / ° C. or less, 0.8 / ° C. or less, 0.7 / ° C. or less, 0.6 / ° C. or less, or 0.5 / ° C. or less. The first rate of change in magnetic permeability (ΔP1) can be, for example, 0 / °C or more and 3 / °C or less, more than 0 / °C and 3 / °C or less, 0.0001 / °C or more and 2 / °C or less, 0.0005 / °C or more and 1 / °C or less, 0.001 / °C or more and 0.9 / °C or less, 0.005 / °C or more and 0.8 / °C or less, 0.005 / °C or more and 0.7 / °C or less, or 0.1 / °C or more and 0.6 / °C or less.

[0071] According to an embodiment of the present invention, the first permeability change rate (ΔP1) is 0 / °C or more, so that it has excellent high temperature stability and can maintain excellent charging efficiency or minimize the degree of decrease in charging efficiency even when the temperature increases.

[0072] According to another embodiment of the present invention, the magnetic part has a second permeability change rate (ΔP2) represented by the following Equation 7 of 0 / ° C. or more.

[0073] JPEG0007625694000010.jpg47164

[0074] Specifically, in the magnetic part, the second permeability change rate (ΔP2) is the difference between the permeability of the magnetic part measured at a temperature of 40°C and the permeability of the magnetic part measured at a temperature of 20°C divided by 20°C.

[0075] Specifically, the second rate of change in magnetic permeability (ΔP2) may be 0 / ° C. or more, more than 0 / ° C., 0.0001 / ° C. or more, 0.0005 / ° C. or more, 0.001 / ° C. or more, 0.005 / ° C. or more, 0.008 / ° C. or more, 0.01 / ° C. or more, or 0.1 / ° C. or more. In addition, the second rate of change in magnetic permeability (ΔP2) may be 3 / ° C. or less, 2 / ° C. or less, 1 / ° C. or less, 0.9 / ° C. or less, 0.8 / ° C. or less, 0.7 / ° C. or less, 0.6 / ° C. or less, or 0.5 / ° C. or less. The second rate of change in magnetic permeability (△P2) can be, for example, 0 / ℃ or more and 3 / ℃ or less, more than 0 / ℃ and 3 / ℃ or less, 0.0001 / ℃ or more and 2 / ℃ or less, 0.0005 / ℃ or more and 1 / ℃ or less, 0.001 / ℃ or more and 0.9 / ℃ or less, 0.005 / ℃ or more and 0.8 / ℃ or less, 0.005 / ℃ or more and 0.7 / ℃ or less, or 0.1 / ℃ or more and 0.5 / ℃ or less.

[0076] According to an embodiment of the present invention, the first permeability change rate (ΔP2) is 0 / °C or more, so that it has excellent high temperature stability and can maintain excellent charging efficiency or minimize the degree of decrease in charging efficiency even when the temperature increases.

[0077] In still another wireless charging device of the present invention, the magnetic part may have a maximum value of magnetic permeability at a temperature of 60°C to 100°C. Specifically, the magnetic part may have a maximum value of magnetic permeability at a temperature of 60°C to 90°C. The magnetic permeability u' at temperatures of 60°C to 100°C may be 90 or more, 95 or more, 98 or more, or 100 or more. The magnetic permeability u' at temperatures of 60°C to 100°C may be 110 or less, 105 or less, 103 or less, or 102 or less. The magnetic permeability u' at temperatures of 60°C to 100°C may be, for example, 90 to 110, 90 to 105, 95 to 105, or 98 to 103.

[0078] When the magnetic part has a maximum magnetic permeability at a temperature of 60°C to 100°C, the heat resistance of the magnetic part can be further improved and high temperature stability of the wireless charging device can be provided, so that excellent charging efficiency can be maintained even at high temperatures.

[0079] When the temperature rises to 25°C to 120°C, the rate of change in magnetic permeability of the polymer type magnetic part may be 10% or less.

[0080] According to the above embodiment, even when the temperature increases to 25°C to 120°C, the magnetic permeability change rate of the magnetic part is 10% or less, so that the heat resistance characteristics of the magnetic part can be further improved and high temperature stability of the wireless charging device can be provided, and excellent charging efficiency can be maintained even at high temperatures.

[0081] Specifically, when the temperature of the magnetic portion rises to 25°C to 120°C, the magnetic permeability change rate of the magnetic portion may be, for example, 9% or less, for example, 8% or less, for example, 7% or less, for example, 5% or less, for example, 3% or less, for example, 2% or less, for example, 1% or less, for example, 0.5% or less, for example, 0.2% or less, for example, 0.1% or less, for example, 0.07% or less.

[0082] The magnetic permeability means a ratio of magnetic flux density generated when magnetized under the influence of a magnetic field to magnetic field strength appearing in a vacuum, and the magnetic permeability is affected by the type of magnetic part. In general, the magnetic permeability of a magnetic part increases with increasing temperature and may tend to decrease rapidly at a certain temperature point.

[0083] The lower the rate of change in magnetic permeability, the more improved the heat resistance and magnetic properties can be. In this case, the occurrence of deformation and damage of the magnetic part at high temperatures can be minimized, and high temperature stability can be provided, so that excellent filling efficiency can be maintained even at high temperatures.

[0084] If the magnetic part has a magnetic permeability change rate of more than 10% in the above temperature range, the heat resistance may be reduced. If the magnetic permeability of the magnetic part increases in the above temperature range and the heat resistance decreases, the magnetic part may be deformed or damaged at high temperatures, which may reduce the magnetic properties and cause a problem of reduced charging efficiency.

[0085] According to an embodiment of the present invention, the permeability is measured at a frequency of 85 kHz using an Agilent Technologies 4294A instrument.

[0086] According to the implementation of the present invention, the magnetic permeability u' of the magnetic part measured at a temperature of 0° C. may be 45-100, 50-100, 55-95, 60-95, 70-90, or 80-92.

[0087] According to realizations of the invention, the magnetic permeability u' of the magnetic part measured at a temperature of 20° C. may be 45-110, 50-110, 55-100, 70-100, 80-95, or 85-95.

[0088] According to implementations of the invention, the magnetic permeability u' of the magnetic part measured at a temperature of 25° C. may be 40-120, 50-120, 60-110, 80-110, 85-100, or 88-99.

[0089] According to the implementation of the present invention, the magnetic permeability u' of the magnetic part measured at a temperature of 40° C. may be 40-120, 50-120, 60-110, 80-110, 85-105, or 90-105.

[0090] According to the implementation of the present invention, the magnetic permeability u' of the magnetic part measured at a temperature of 60°C can be 40-150, 50-140, 80-140, 90-130, 90-120, or 90-110.

[0091] According to the implementation of the present invention, the magnetic permeability u' of the magnetic part measured at a temperature of 80°C can be 40-150, 50-140, 80-140, 90-130, 90-120, or 90-110.

[0092] According to the implementation of the present invention, the magnetic permeability u' of the magnetic part measured at a temperature of 100°C may be 40-120, 50-120, 60-110, 80-110, 85-105, or 90-105.

[0093] According to the implementation of the present invention, the magnetic permeability u' of the magnetic part measured at a temperature of 120°C can be 40-120, 50-120, 60-110, 80-110, 85-105, or 90-105.

[0094] When the magnetic permeability of the magnetic part at each temperature satisfies the above range, the wireless charging device can satisfy the physical property range of the wireless charging device according to the embodiment of the present invention, thereby minimizing the occurrence of deformation and damage of the magnetic part at high temperatures and improving charging efficiency.In addition, since the wireless charging device can provide high temperature stability, it can maintain excellent charging efficiency or minimize the degree of decrease thereof even when the temperature increases.

[0095] Furthermore, when wireless power having a frequency of 85 kHz and an output of 6.6 kW is transmitted to the coil unit for 10 to 30 minutes, the inductance change rate at 150° C. may increase to, for example, 0.3% or less, for example, 0.25% or less, for example, 0.2% or less. If the inductance change rate at 150° C. increases beyond 0.3%, the heat resistance may decrease, and in this case, the magnetic unit may be deformed or damaged at high temperatures, which may decrease the magnetic properties and cause a problem of reduced charging efficiency.

[0096] Meanwhile, according to an embodiment of the present invention, when the heat temperature of the underside of the polymer type magnetic part rises to 25°C to 100°C, the rate of change in filling efficiency may be 1% or less, for example, 0.8% or less, for example, 0.5% or less, for example, 0.3% or less, for example, 0.2% or less, for example, 0.1% or less.

[0097] The heat generation temperature of the underside of the magnetic part is measured using the T / GUARD405-SYSTEM manufactured by QUALITROL Inc. Specifically, the heat generation temperature of the underside of the magnetic part is measured based on the center (maximum heat generation temperature) of the first magnetic part, which is the position corresponding to the coil part.

[0098] Generally, when the heat generation temperature of the magnetic part increases, the charging efficiency may decrease due to loss caused by the generated heat. However, when a magnetic part with improved heat resistance is used according to an embodiment of the present invention, the decrease in charging efficiency may be minimized even if heat is generated (even if heat is intense) due to the heat resistance. In other words, excellent charging efficiency may be maintained even if heat generation increases within the wireless charging device.

[0099] According to one embodiment of the present invention, the physical properties of inductance and permeability can be controlled by the material of the magnetic portion.

[0100] Specifically, the physical properties of the inductance and magnetic permeability can be adjusted to a desired range by using a magnetic part, for example, a polymer magnetic part, in the embodiment of the present invention. The physical properties of the inductance and magnetic permeability can be changed depending on the type, particle size, and content of the filler contained in the polymer magnetic part. Alternatively, the physical properties of the inductance and magnetic permeability can be changed depending on the type and content of the binder resin contained in the polymer magnetic part. Alternatively, the physical properties of the inductance and magnetic permeability can be changed depending on the type and content of various additives added to the polymer magnetic part. Alternatively, the physical properties of the inductance and magnetic permeability can be changed depending on the combination constituting the polymer magnetic part, so that the physical properties of the inductance and magnetic permeability can be effectively controlled by selecting the appropriate type and content of the filler, binder, and / or additive.

[0101] 1 and 2 show exploded and perspective views, respectively, of a wireless charging device according to one implementation.

[0102] 1 and 2, a wireless charging device 10 according to an embodiment of the present invention includes a coil unit 200 and a magnetic unit 300 disposed on the coil unit 200. The wireless charging device 10 may further include a support unit 100 that supports the coil unit 200, a shield unit 400 that is disposed on the magnetic unit, and a housing 600 that protects the components. Hereinafter, each component of the wireless charging device will be described in detail.

[0103] [Coil section] A wireless charging device according to an embodiment of the present invention includes a coil unit through which an alternating current can flow to generate a magnetic field.

[0104] The coil portion may include a conductive wire. The conductive wire includes a conductive material. For example, the conductive wire may include a conductive metal. Specifically, the conductive wire may include one or more metals selected from the group consisting of copper, nickel, gold, silver, zinc, and tin.

[0105] The conductive wire may also include 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.

[0106] The diameter of the conductive wire can be, for example, 1 mm to 10 mm, 2 mm to 7 mm, or 3 mm to 5 mm.

[0107] The conductive wire may be wound in a planar coil shape. Specifically, the planar coil may include a planar spiral coil. The planar shape of the coil may be, but is not limited to, an ellipse, a polygon, or a polygon with rounded corners.

[0108] The outer diameter of the planar coil may be 5 cm to 100 cm, 10 cm to 50 cm, 10 cm to 30 cm, 20 cm to 80 cm, or 50 cm to 100 cm. As a specific example, the planar coil may have an outer diameter of 10 cm to 50 cm.

[0109] Additionally, the inner diameter of the flat coil may be 0.5 cm to 30 cm, 1 cm to 20 cm, or 2 cm to 15 cm.

[0110] The number of turns of the planar coil may be 1 to 50, 5 to 30, 5 to 20, or 7 to 15. As a specific example, the planar coil may be formed by winding the conductive wire 7 to 15 times.

[0111] Additionally, within the planar coil shape, the spacing between the conductive wires may be 0.1 cm to 1 cm, 0.1 cm to 0.5 cm, or 0.5 cm to 1 cm.

[0112] When the planar coil dimensions are within the preferred specification range as described above, the coil can be suitable not only for fields requiring large-capacity power transmission such as electric vehicles, but also for various personal transportation fields such as electric bikes, electric kickboards, electric scooters, electric wheelchairs, and electric bicycles.

[0113] The coil portion may be disposed at a certain distance from the magnetic portion. For example, the distance between the coil portion and the magnetic portion may be 0.2 mm or more, 0.5 mm or more, 0.2 mm to 3 mm, or 0.5 mm to 1.5 mm.

[0114] [Magnetic part] The magnetic portion may form a magnetic path for a magnetic field generated around the coil portion and may be disposed between the coil portion and the shield portion.

[0115] The magnetic portion may be disposed at a certain distance from the shield portion. For example, the distance between the magnetic portion and the shield portion may be 3 mm or more, 5 mm or more, 3 mm to 10 mm, or 4 mm to 7 mm.

[0116] The magnetic portion may be disposed at a certain distance from the coil portion. For example, the distance between the magnetic portion and the coil portion may be 0.2 mm or more, 0.5 mm or more, 0.2 mm to 3 mm, or 0.5 mm to 1.5 mm.

[0117] The magnetic part may include a polymer type magnetic part (first magnetic part) containing a filler and a binder resin.

[0118] The magnetic portion may further include a metal-based magnetic portion, for example a nanocrystalline magnetic portion (second magnetic portion).

[0119] The magnetic part may further include an oxide-based magnetic part (second magnetic part). The magnetic portion may include a composite of these (a first magnetic portion and a second magnetic portion).

[0120] [Polymer type magnetic part] The magnetic part may include a polymer type magnetic part including a binder resin and a filler. Specifically, the magnetic part may include a polymer type magnetic part including the binder resin and a filler dispersed in the binder resin. The polymer type magnetic part may include a polymer type magnetic block (PMB).

[0121] According to an embodiment of the present invention, by including a polymer-type magnetic portion containing the filler and binder resin, the inductance deviation, inductance change rate, and permeability change rate targeted in the present invention can be achieved.

[0122] The polymer-type magnetic part may have fewer defects overall over a wide area and may be less damaged by impact because the fillers are bound to each other by the binder resin.

[0123] The filler may be an oxide filler such as ferrite (Ni-Zn, Mg-Zn, Mn-Zn ferrite, etc.), a metal filler such as permalloy, sendust, nanocrystalline magnetic material, or a mixed powder thereof. More specifically, the filler may be sendust particles having an Fe-Si-Al alloy composition.

[0124] As an example, the filler may have the composition of Formula 1 below. [Chemical formula 1] Fe 1-a-b-c S a X b Yc In the above formula, X is Al, Cr, Ni, Cu, or a combination thereof, and Y is Mn, B, Co, Mo, or a combination thereof, and 0.01≦a≦0.2, 0.01≦b≦0.1, and 0≦c≦0.05. Specifically, in the above formula, X can be Al, Cr, or a combination thereof.

[0125] The filler may include sendust. The average particle size (D50) of the filler may be in the range of about 1 μm to 300 μm, about 10 μm to 200 μm, or about 30 μm to 150 μm. When the average particle size of the filler satisfies the above range, the heat resistance of the polymer-type magnetic part can be improved, and the inductance change rate and the magnetic permeability change rate due to temperature rise can be reduced. This can improve the charging efficiency of the wireless charging device.

[0126] The filler may be included in an amount of 60% by weight or more, 70% by weight or more, or 85% by weight or more based on the total weight of the polymer-type magnetic part.

[0127] For example, the polymer-type magnetic part may contain the filler in an amount of 60% to 90% by weight, 70% to 90% by weight, 75% to 90% by weight, 78% to 90% by weight, 80% to 90% by weight, 85% to 90% by weight, 87% to 90% by weight, or 89% to 90% by weight. If the filler content is less than 60% by weight, the heat resistance of the polymer-type magnetic part may decrease, and the inductance change rate and the magnetic permeability change rate due to temperature rise may increase rapidly. In particular, the inductance deviation of the wireless charging device may be less than 0 (zero). This may cause deformation and damage of the magnetic part at high temperatures, which may reduce the magnetic properties and the charging efficiency.

[0128] The melting point (Tm) of the binder resin may be 150° C. to 210° C. For example, the melting point (Tm) of the binder resin may be 160° C. to 200° C., e.g., 160° C. to 180° C. When the melting point (Tm) of the binder resin satisfies the above range, the amount of position change at temperatures of 150° C. to 180° C. can be minimized, and the heat resistance and magnetic properties of the magnetic part can be further improved, thereby improving charging efficiency.

[0129] The binder resin may include one or more selected from the group consisting of polyimide resin, polyamide resin, polyamideimide resin, polycarbonate resin, acrylonitrile-butadiene-styrene (ABS) resin, polypropylene resin, polyethylene resin, polystyrene resin, polyphenylsulfide (PSS) resin, polyetheretherketone (PEEK) resin, silicone resin, acrylic resin, polyurethane resin, polyester resin, isocyanate resin, and epoxy resin.

[0130] The binder resin may be a curable resin. Specifically, the binder resin may be a photocurable resin and / or a thermosetting resin, and in particular, may be a resin that can be cured to exhibit adhesiveness. More specifically, the binder resin may be a resin that includes one or more functional groups or sites 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 that includes one or more functional groups or sites that can be cured by active energy, such as an epoxide group, a cyclic ether group, a sulfide group, an acetal group, or a lactone group. Such functional groups or sites may be, for example, an isocyanate group (-NCO), a hydroxyl group (-OH), or a carboxyl group (-COOH).

[0131] Specifically, the binder resin may include one or more resins selected from the group consisting of polyamide resins, polycarbonate resins, and polypropylene resins.

[0132] In addition, even if a resin with excellent heat resistance is used as the binder resin, if the mixture with the filler is not well-mixed, it may be difficult to achieve the inductance deviation, inductance change rate, and magnetic permeability change rate that are the objectives of the embodiment of the present invention. Therefore, it may be important to select the binder resin and the filler so that the mixture is desirable.

[0133] For example, the binder resin may be a polyamide resin, and the filler may be sendust.

[0134] The polymer magnetic portion may contain the binder resin in an amount of 5% by weight to 40% by weight, 10% by weight to 40% by weight, 10% by weight to 20% by weight, 5% by weight to 20% by weight, 5% by weight to 15% by weight, or 7% by weight to 15% by weight.

[0135] According to an embodiment of the present invention, in order to satisfy the target inductance deviation, inductance change rate, and magnetic permeability change rate, the binder resin may be contained in an amount of 10% by weight to 40% by weight, and the filler may be contained in an amount of 80% by weight to 90% by weight.

[0136] Specifically, the binder resin may be contained in an amount of 10% by weight to 20% by weight, and the filler may be contained in an amount of 85% by weight to 90% by weight.

[0137] The polymer magnetic part may further include an additive. Specifically, the polymer magnetic part may further include one or more insulating coating agents selected from the group consisting of phosphoric acid and silane. The insulating coating agent is an additive used for forming an oxide film, and the insulating coating agent may be added in an amount of 0.1% by weight to 10% by weight, specifically 1% by weight to 8% by weight or 2% by weight to 8% by weight, based on the total weight of the polymer magnetic part.

[0138] When the additive is included in the above range, the heat resistance of the polymer magnetic part can be improved, and the inductance change rate and the magnetic permeability change rate due to temperature rise can be reduced. In particular, the inductance deviation can be 0 or more, and thus the charging efficiency of the wireless charging device can be further improved.

[0139] The polymer type magnetic part can be elongated at a certain ratio. For example, the elongation rate of the polymer type magnetic part can be 0.5% or more. The elongation property is difficult to obtain in a ceramic magnetic part not using a polymer, and even if a large-area magnetic part is distorted due to an impact, damage can be reduced. Specifically, the elongation rate of the polymer type magnetic part can be 0.5% or more, 1% or more, or 2.5% or more. There is no particular upper limit to the elongation rate, but if the content of the polymer resin is increased to improve the elongation rate, the physical properties of the magnetic part, such as the inductance, can be reduced, so the elongation rate is preferably 10% or less.

[0140] The polymer type magnetic portion exhibits a small rate of change in physical properties before and after impact, which is far superior to that of a typical ferrite magnetic sheet.

[0141] In this specification, the change rate (%) of a certain physical property before and after impact can be calculated by the following formula. Characteristic change rate (%) = |characteristic value before impact - characteristic value after impact| / characteristic value before impact x 100

[0142] For example, the polymer-type magnetic part may have an inductance change rate of less than 5% or 3% or less before and after an impact when it is dropped from a height of 1 m. More specifically, the inductance change rate may be 0% to 3%, 0.001% to 2%, or 0.01% to 1.5%. When within the above range, the inductance change rate before and after the impact is relatively small, and therefore the stability of the magnetic part may be improved.

[0143] In addition, the polymer-type magnetic part may have a quality factor (Q factor) change rate before and after impact when it is dropped from a height of 1 m of 0% to 5%, 0.001% to 4%, or 0.01% to 2.5%. When within the above range, there is little change in physical properties before and after impact, so that the stability and impact resistance of the magnetic part can be further improved.

[0144] In addition, the polymer magnetic part may have a resistance change rate of 0% to 2.8%, 0.001% to 1.8%, or 0.1% to 1.0% before and after impact when it is dropped from a height of 1 m. When the change rate is within the above range, the resistance value can be well maintained at a certain level or less even when it is repeatedly used in an environment where actual impacts and vibrations are applied.

[0145] In addition, the polymer-type magnetic part may have a charging efficiency change rate before and after impact when it is dropped from a height of 1 m of 0% to 6.8%, 0.001% to 5.8%, or 0.01% to 3.4%. When within the above range, the large-area magnetic part can maintain its physical properties more stably even if impacts or distortions occur repeatedly.

[0146] [Nanocrystalline magnetic part] The magnetic portion may further include a nanocrystalline magnetic portion.

[0147] When the nanocrystalline magnetic part is applied, the greater the distance from the coil part, the lower the inductance Ls of the coil part becomes, but the lower the resistance Rs becomes, so that the coil quality factor (Q factor: Ls / Rs) becomes higher, thereby improving charging efficiency and reducing heat generation.

[0148] For example, the nanocrystalline magnetic portion may be an Fe-based nanocrystalline magnetic portion, specifically an Fe-Si-Al-based nanocrystalline magnetic portion, an Fe-Si-Cr-based nanocrystalline magnetic portion, or an Fe-Si-B-Cu-Nb-based nanocrystalline magnetic portion.

[0149] More specifically, the nanocrystalline magnetic part may be an Fe-Si-B-Cu-Nb-based nanocrystalline magnetic part, in which case it is preferable that Fe is 70% to 85%, Si and B are 10% to 29%, and Cu and Nb are 1% to 5% (here, "%" refers to the percentage of the number of a specific element relative to the total number of elements constituting the magnetic part). In the above composition range, the Fe-Si-B-Cu-Nb-based alloy can be easily formed into a nanophase crystalline material by heat treatment.

[0150] The nanocrystalline magnetic portion can be manufactured, for example, by manufacturing an Fe-based alloy by rapid solidification (RSP) using melt spinning, and then performing a magnetic field-free heat treatment at a temperature range of 300°C to 700°C for 30 minutes to 2 hours to obtain the desired magnetic permeability.

[0151] If the heat treatment temperature is less than 300°C, nanocrystalline material is not sufficiently generated, so that the desired magnetic permeability cannot be obtained and the heat treatment time may be long, and if it exceeds 700°C, the magnetic permeability may be significantly reduced by overheating. In addition, the desired magnetic permeability can be adjusted by lengthening the heat treatment time when the heat treatment temperature is low, and shortening the heat treatment time when the heat treatment temperature is high.

[0152] It is difficult to make the nanocrystalline magnetic portion thick in the manufacturing process, and it can be formed to a thickness of, for example, 15 μm to 35 μm.

[0153] The nanocrystalline magnetic portion may have a specific range of magnetic properties near a standard frequency for wireless charging of electric vehicles, and may have a certain level of magnetic properties near a standard frequency for wireless charging in various personal transportation fields such as electric bikes, electric kickboards, electric scooters, electric wheelchairs, and electric bicycles.

[0154] For example, the nanocrystalline magnetic portion may have a permeability of 500 to 150,000 at a frequency of 85 kHz and a permeability loss of 100 to 50,000. As an example, when the nanocrystalline magnetic portion includes a crushed nanocrystalline magnetic material, it may have a permeability of 500 to 3,000 at a frequency of 85 kHz and a permeability loss of 100 to 1,000. As another example, when the nanocrystalline magnetic portion includes a non-crushed nanocrystalline magnetic material, it may have a permeability of 5,000 to 150,000 at a frequency of 85 kHz and a permeability loss of 1,000 to 10,000.

[0155] [Oxide magnetic part] The magnetic portion may include an oxide-based magnetic portion.

[0156] For example, the oxide-based magnetic part may be a ferrite-based material, and may be represented by the specific chemical formula MOFe2O3 (wherein M is one or more divalent metal elements such as Mn, Zn, Cu, Ni, etc.). The ferrite-based material may be a sintered body, which is advantageous in terms of magnetic properties such as magnetic permeability, and may be a ferrite sintered body more specifically. The ferrite-based material may be manufactured into a sheet or block shape by mixing raw material components, calcining, and pulverizing the mixture, mixing the mixture with a binder resin, forming, and sintering the mixture.

[0157] More specifically, the oxide-based magnetic portion may be Ni-Zn-based, Mg-Zn-based, or Mn-Zn-based ferrite, and in particular, Mn-Zn-based ferrite can exhibit high magnetic permeability, low magnetic permeability loss, and high saturation magnetic flux density over a temperature range from room temperature to 100°C or higher at a frequency of 79 kHz to 90 kHz.

[0158] The Mn-Zn ferrite contains 66 mol% to 70 mol% of iron oxide 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 contain SiO2, CaO, Nb2O5, ZrO2, SnO, etc. as auxiliary components. The Mn-Zn ferrite can be manufactured into a sheet or block shape by mixing the main components in a predetermined molar ratio, calcining in air at a temperature of 800°C to 1100°C for 1 to 3 hours, adding auxiliary components, pulverizing, mixing an appropriate amount of a binder resin such as polyvinyl alcohol (PVA), pressure-molding using a press, and then heating to 1200°C to 1300°C and calcining for 2 hours or more. Thereafter, the mixture is processed by a wire saw or a water jet, etc., as necessary, and cut into a desired size.

[0159] The oxide-based magnetic part may have a specific range of magnetic properties near a standard frequency for wireless charging of electric vehicles, and may have a certain level of magnetic properties near a standard frequency for wireless charging in various personal transportation fields such as electric bikes, electric kickboards, electric scooters, electric wheelchairs, and electric bicycles.

[0160] For example, the oxide-based magnetic portion, specifically the ferrite-based material, may have a magnetic permeability of 1000-5000, 1000-4000, or 2000-4000 at a frequency of 85 kHz, and a magnetic permeability loss of 0-1000, 0-100, or 0-50.

[0161] [Magnetic part manufacturing method] The magnetic portion may include, for example, a polymer-type magnetic portion, which may be manufactured by a sheet-forming process, such as mixing a filler and a binder resin to form a slurry, forming the slurry into a sheet, and curing the slurry.

[0162] In addition, in order to manufacture a large-area magnetic part having a certain thickness using a thermoplastic resin, it can be formed into a three-dimensional structure using a mold. Specifically, the filler and the thermoplastic resin can be kneaded using mechanical shear force and heat, and then pelletized using a machine to manufacture a block using a method of injection molding.

[0163] The manufacturing method may be a conventional sheet or block forming method. The molding may be performed by injecting the raw material of the magnetic part into a mold by injection molding. More specifically, the magnetic part may be manufactured by mixing a filler and a polymer resin composition to obtain a raw material composition, and then injecting the raw material composition 701 into a mold 703 by an injection molding machine 702 as shown in FIG. 9. In this case, the internal shape of the mold 703 may be designed to have a three-dimensional structure, so that the three-dimensional structure of the magnetic part may be easily realized. This process may be advantageous in terms of structural freedom compared to the case where an existing sintered ferrite sheet is used as the magnetic part.

[0164] [Magnetic part area and thickness] The magnetic portion may be a magnetic sheet, a magnetic sheet stack, or a magnetic block.

[0165] The magnetic part may have a large area, specifically 200 cm 2 More than 400cm 2 or more, or 600cm 2 The magnetic portion may have an area of ​​10,000 cm or more. 2 It may have the following areas:

[0166] The large-area magnetic part is constructed by combining a number of unit magnetic parts, and the area of ​​the unit magnetic part is 60 cm 2 Over 90cm 2 or more, or 95cm 2 ~900cm 2 It could be.

[0167] 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 part may be manufactured by a method for manufacturing a normal film or sheet.

[0168] The magnetic sheet laminate may be one in which 20 or more, or 50 or more, of the magnetic sheets are laminated together. The magnetic sheet laminate may be one in which 150 or less, or 100 or less, of the magnetic sheets are laminated together.

[0169] The thickness of the magnetic block may be 1 mm or more, 2 mm or more, 3 mm or more, or 4 mm or more, and the thickness of the magnetic block may be 10 mm or less.

[0170] [Shield part] The wireless charging device 10 according to the above embodiment may further include a shielding part 400 that serves to improve the efficiency of wireless charging by shielding electromagnetic waves. The shield portion is disposed on one side of the coil.

[0171] The shielding portion includes a metal plate, and is made of aluminum. Alternatively, other metals or alloys having electromagnetic wave shielding properties may be used.

[0172] The thickness of the shield portion may be 0.2 mm to 10 mm, 0.5 mm to 5 mm, or 1 mm to 3 mm.

[0173] The area of ​​the shield is 200 cm 2 More than 400cm 2 or more, or 600cm 2 It could be more than that.

[0174] [housing] The wireless charging device 10 according to the above embodiment may further include a housing 600 that houses the coil unit 200 and the magnetic unit 300 .

[0175] In addition, the housing 600 allows components such as the coil unit 200, the shield unit 400, and the magnetic unit 300 to be appropriately arranged and assembled. The shape (structure) of the housing may be arbitrarily set according to the components contained therein or according to the environment. The material and structure of the housing may be the same as those of a typical housing used in a wireless charging device.

[0176] [Support part] The wireless charging device 10 according to the above embodiment may further include a support 100 for supporting the coil unit 200. The material and structure of the support may be the same as those of a typical support used in a wireless charging device. The support may have a flat plate structure or a grooved structure that conforms to the shape of the coil so as to fix the coil unit.

[0177] [Various examples of wireless charging devices] 3a and 3b show cross-sectional views of wireless charging devices of various structures according to the implementation of the present invention.

[0178] 3a, a wireless charging device according to an embodiment may include a coil unit 200, a magnetic unit 300 disposed on the coil unit 200, and a shield unit 400 spaced apart from the magnetic unit. Also, an empty space or spacer unit 700 may be further included between the magnetic unit 300 and the shield unit 400. In this case, the magnetic unit 300 may include a polymer type magnetic unit including a filler and a binder resin.

[0179] In addition, the magnetic part may have a planar structure or a three-dimensional structure, which may improve charging efficiency and heat dissipation characteristics.

[0180] 3b, the magnetic part may include two or more types of hybrid magnetic parts. Specifically, the magnetic part may include a first magnetic part 300 and a second magnetic part 500 that are different from each other.

[0181] The first magnetic part 300 may include a polymer-type magnetic part, and the second magnetic part 500 may include a nanocrystalline or oxide-based magnetic part.

[0182] The first magnetic part 300, which is the polymer type magnetic part, includes an outer part 310 corresponding to a portion where the coil part 200 is disposed, and a central part 320 surrounded by the outer part 310, and the thickness of the outer part 310 may be greater than the thickness of the central part 320. In this case, in the first magnetic part, the outer part and the central part may be integrally formed with each other. Alternatively, in the first magnetic part, the outer part and the central part may have the same thickness.

[0183] In this way, by making the thickness of the magnetic part thicker near the coil where electromagnetic energy is concentrated during wireless charging and making the thickness of the magnetic part thinner in the center where the electromagnetic energy density is relatively low because there is no coil, the electromagnetic waves concentrating around the coil can be effectively focused to improve charging efficiency, and the distance between the coil and the shield part can be firmly maintained without a separate spacer, thereby reducing material costs and process costs that would be incurred by using spacers, etc.

[0184] In the first magnetic part, the outer shell part may have a thickness 1.5 times or more thicker than that of the central part. With this thickness ratio, electromagnetic waves concentrated around the coil can be more effectively focused to improve charging efficiency, and it is also advantageous for heat prevention and weight reduction. Specifically, the thickness ratio of the outer shell part / the central part in the first magnetic part may be 2 or more, 3 or more, or 5 or more. Also, 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.

[0185] The thickness of the outer portion of the first magnetic part may be 1 mm or more, 3 mm or more, or 5 mm or more, and 30 mm or less, 20 mm or less, or 11 mm or less. Furthermore, the thickness of the center portion of the first magnetic part 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 part may have a thickness of 5 mm to 11 mm, and the center portion may have a thickness of 0 mm to 5 mm.

[0186] When the thickness of the center portion 320 of the first magnetic part 300 is zero, the first magnetic part 300 may have a shape in which the center portion 320 is open (e.g., a donut shape). In this case, the first magnetic part may effectively improve charging efficiency even with a smaller area.

[0187] For example, referring to FIG. 3b, the wireless charging device may include a coil unit 200 and a magnetic unit disposed on the coil unit 200, and the magnetic unit may include a first magnetic unit 300 and a second magnetic unit 500. Also, at least a part of the second magnetic unit may contact the shield unit 400. This allows heat generated in the second magnetic unit to be effectively discharged through the shield unit. For example, if the second magnetic unit is a nanocrystalline or oxide-based magnetic unit and is sheet-shaped, one surface of the second magnetic unit may be in contact with the shield unit. Specifically, the second magnetic unit may be attached to one surface of the shield unit facing the first magnetic unit. The second magnetic unit may be attached to one surface of the shield unit with a thermally conductive adhesive to further enhance the heat dissipation effect. The thermally conductive adhesive may include a thermally conductive material such as a metal-based, carbon-based, or ceramic-based material, and may be, for example, an adhesive resin in which thermally conductive particles are dispersed.

[0188] In addition, according to an embodiment of the present invention, a first magnetic part that satisfies the above-mentioned magnetic permeability change rate, for example a polymer-type magnetic part, can be included and arranged in various structures in which this is combined with magnetic parts made of other materials, allowing for a variety of designs within a range that does not impede the effects of the present invention.

[0189] The charging efficiency of a wireless charging device according to implementations of the present invention may be 85% or more, 88% or more, 89% or more, 90% or more, or 91% or more.

[0190] For example, when wireless power having a frequency of 85 kHz and an output of 6.6 kW is transmitted to the coil unit for 15 minutes, the charging efficiency may be 87% or more, 88% or more, 89% or more, 90% or more, or 91% or more.

[0191] Therefore, the wireless charging device can be useful not only for electric vehicles that require large-capacity power transmission between a transmitter and a receiver, but also for various personal transportation means such as electric motorcycles, electric kickboards, electric scooters, electric wheelchairs, and electric bicycles.

[0192] [Magnetic elements] According to an embodiment of the present invention, a magnetic element can be provided that includes a polymer-type magnetic part (first magnetic part) containing a filler and a binder resin, and that has a first magnetic permeability change rate (ΔP1) represented by Equation 6 of 0 / °C or more. The configurations and features of the respective components of the polymer-type magnetic part are as described above.

[0193] The magnetic element according to the embodiment of the present invention includes a polymer-type magnetic part having the above-mentioned characteristics, and thus can provide high-temperature stable characteristics, thereby solving the problem of reduced charging efficiency due to deformation and damage of the magnetic element at high temperatures.

[0194] In particular, by optimally combining and adjusting the type and content of the binder resin, the filler, and various additives, the present invention can achieve the desired inductance deviation, inductance change rate, and permeability change rate of the magnetic part within a specific range. In this case, the charging efficiency can be improved, and the reduction in charging efficiency can be minimized even when the temperature rises or heat generation increases.

[0195] (Transportation) The wireless charging device according to the above embodiment can be useful not only for electric vehicles that require large-capacity power transmission between a transmitter and a receiver, but also for various personal transportation means such as electric motorcycles, electric kickboards, electric scooters, electric wheelchairs, and electric bicycles.

[0196] Referring to FIG. 10, an electric vehicle 1 according to one implementation includes a wireless charging device according to the implementation as a receiver 720.

[0197] The wireless charging device functions as a receiver for wireless charging of the electric vehicle 1 and can receive power from a transmitter 730 of the wireless charging system.

[0198] The transportation means includes a wireless charging device, and the configuration and features of each component of the wireless charging device are as described above.

[0199] The vehicle may further include a battery that receives power from the wireless charging device. The wireless charging device wirelessly receives the power and transmits it to the battery, which may supply power to a drivetrain of the electric vehicle. The battery may be charged by power transmitted from the wireless charging device or another additional wired charging device.

[0200] The transportation means may further include a signal transmitter for transmitting information regarding charging to a transmitter of the wireless charging system. Such information regarding charging may be charging efficiency such as charging speed, charging state, and the like.

[0201] (Example) In the following, specific examples of the present invention will be presented. However, the examples described below are merely for the purpose of specifically illustrating or explaining the present invention, and the present invention should not be limited thereby.

[0202] (Example 1: Manufacturing of wireless charging device) Step 1) Manufacturing polymer type magnetic part (PMB magnetic sheet) Using 15 weight percent polyamide resin (product name: L1724k, Daicel-Evonik) as the binder resin, 80 weight percent Sendust (product name: C1F-02A, Crystallite Technology) as the filler, and 5 weight percent phosphoric acid and silane as additives, pellets were produced using an extruder at a temperature of approximately 170°C to 200°C and a speed of 120 rpm to 150 rpm. The pellets were then injected using an injector at a temperature of approximately 250°C to obtain a 5 mm thick polymer-type magnetic part (PMB magnetic sheet).

[0203] Step 2) Manufacturing wireless charging devices Using the magnetic part of step 1, a wireless charging device was obtained, which included a coil part including a conductive wire, the magnetic part, and a shield part.

[0204] Comparative Example 1 A magnetic part and a wireless charging device including the same were obtained in the same manner as in Example 1, except that the additives of phosphoric acid and silane were not used.

[0205] (Test Example) (1) Permeability of the magnetic part The magnetic permeability of the magnetic portion was measured at a frequency of 85 kHz using an Agilent 4294A instrument.

[0206] (2) Inductance The inductance was measured using an LCR meter (HIOKI IM3536 device) with an inductance of 30 μH, a coil diameter of 5 mm, 1000 square planar coils, a magnetic part with a volume of 320 mm × 320 mm × 5 mm, and an aluminum (Al) shield part with a volume of 350 mm × 350 mm × 2 mm. After connecting the device to the coil part, the setting value of the LCR meter was set to 85 kHz, and the inductance (Ls) was measured, which was used to measure the inductance deviation and the inductance change rate.

[0207] In the examples and comparative examples, the measurements were performed under the same conditions, and the measured inductance deviation and inductance change rate were calculated and shown in Tables 2 and 3 below.

[0208] (3) Charging efficiency measurement The charging efficiency was measured according to the SAE J2954 WPT2 Z2 class standard test method. Specifically, the coil and frame of the SAE J2954 WPT2 Z2 class standard test standard were applied, and the magnetic part, spacer, and aluminum shield were laminated to manufacture a receiving pad (35cm x 35cm) and a transmitting pad (75cm x 60cm), and the charging efficiency was evaluated under the same conditions of 85kHz frequency and 6.6kW output power.

[0209] (4) Fever temperature measurement The wireless charging devices obtained in the above examples and comparative examples were placed in a housing to obtain wireless charging devices.

[0210] The underside temperature of the magnetic part was measured for the wireless charging devices obtained in the examples and comparative examples under the SAE J2954 WPT2 Z2 class standard test charging efficiency measurement conditions when wireless power having a frequency of 85 kHz and an output of 6.6 kW was transmitted to the coil part for 30 minutes.

[0211] Specifically, the underside temperature of the magnetic part was measured using Qualitrol's T / GUARD405-SYSTEM, based on the center (maximum heat generation temperature) of the position corresponding to the coil part on the underside of the magnetic part of the example and comparative example. The measurement results are shown in the following Tables 1 to 3 and Figs.

[0212] JPEG0007625694000011.jpg80162

[0213] JPEG0007625694000012.jpg47164

[0214] JPEG0007625694000013.jpg195165

[0215] As can be seen from Tables 1 to 3 and Figures 4 and 5, the wireless charging device of Example 1 has inductance deviation, inductance change rate, and permeability change rate, etc., all of which are within the range of the examples of the present invention compared to the wireless charging device of Comparative Example 1. As a result, it was confirmed that the charging efficiency is improved and that the charging efficiency is maintained or its rate of decrease is low even when the heat generation temperature increases.

[0216] Specifically, as can be seen from Table 1 and Figures 4 and 5, it can be seen that the charging efficiency of the wireless charging device of Example 1 is maintained almost constant within 0.3% from the beginning of wireless power transmission to when wireless power is transmitted for 15 minutes, even though the heat generation temperature of the coil unit and the magnetic unit is further increased compared to the wireless charging device of Comparative Example 1. In contrast, it can be seen that the heat generation temperature of the magnetic unit of Comparative Example 1 is slightly lower than that of Example 1, but the rate of decrease in charging efficiency is further increased.

[0217] Furthermore, as can be seen from Table 2 and FIG. 6, in the wireless charging device of Example 1, the inductance change rate at 150° C. is roughly maintained or increases over time compared to the wireless charging device of Comparative Example 1.

[0218] Specifically, when wireless power is transmitted for 10 to 30 minutes, the inductance change rate of the wireless charging device of Example 1 gradually increases to 0.3% or less at 150°C compared to the wireless charging device of Comparative Example 1, while the inductance change rate of the wireless charging device of Comparative Example 1 decreases more rapidly than the inductance change rate of the wireless charging device of Example 1. That is, in the case of the wireless charging device of Example 1, there is no change in magnetic permeability even at the high temperature of 150°C, so there is almost no inductance change rate. On the other hand, in the case of the wireless charging device of Comparative Example 1, when wireless power is transmitted for 30 minutes, the inductance change rate decreases rapidly while maintaining a negative (-) value.

[0219] As can be seen from Table 3 and Figures 7 and 8, in the case of the wireless charging device of Example 1, the inductance deviation (ID1) at 40°C, 60°C, 80°C, and 100°C all had positive (+) values, and the first permeability change rate (ΔP1) and the second permeability change rate (ΔP2) of the magnetic part all had positive (+) values. In addition, when the temperature rose from 25°C to 120°C, the inductance change rate and the permeability change rate of the polymer magnetic part were each within 10%.

[0220] On the other hand, in the case of the wireless charging device of Comparative Example 1, the inductance deviation (ID1) at 40°C, 60°C, 80°C, and 100°C all had negative (-) values, and the first rate of change in magnetic permeability (ΔP1) and the second rate of change in magnetic permeability (ΔP2) of the magnetic part all had negative (-) values. Furthermore, when the temperature rose from 25°C to 120°C, the rate of change in inductance dropped sharply, and the rate of change in magnetic permeability of the polymer-type magnetic part also changed sharply.

[0221] From the above results, it was confirmed that the wireless charging device including the polymer-type magnetic portion of Example 1 had excellent high-temperature stability and therefore maintained excellent charging efficiency even at high temperatures. [Explanation of symbols]

[0222] 1: Transportation (electric vehicle) 10, 10a, 10b: Wireless charging device 100: Support part 200: Coil section 300: Magnetic part (first magnetic part) 310: Outer shell 320: Center 400: Shield section 500: 2nd magnetic part 600: Housing 700: Spacer part 701: Raw material composition 702: Injection molding machine 703: Mold 720:Receiver 730:Transmitter A-A': Incision line

Claims

1. A coil portion; a magnetic portion disposed on the coil portion, the magnetic portion includes a polymer type magnetic portion including a binder resin, a filler, and an additive; The additive comprises one or more insulating coating agents selected from the group consisting of phosphoric acid and silane; The content of the insulating coating agent is 2% by weight to 8% by weight based on the total weight of the polymer-type magnetic part, A wireless charging device in which an inductance deviation (ID1) at 80° C., represented by the following formula 1, is 0 (zero) or more: [Formula 1] where I25 is the inductance of the wireless charging device measured at a temperature of 25° C. I80 is the inductance of the wireless charging device measured at a temperature of 80°C.

2. 2. The wireless charging device according to claim 1, wherein an inductance deviation (ID2) at 60° C., expressed by the following formula 2, is 0 or more: [Formula 2] where I25 is the inductance of the wireless charging device measured at a temperature of 25° C. I60 is the inductance of the wireless charging device measured at a temperature of 60°C.

3. 2. The wireless charging device according to claim 1, wherein an inductance deviation (ID3) at 100° C., expressed by the following formula 3, is 0 or more: [Formula 3] where I25 is the inductance of the wireless charging device measured at a temperature of 25° C. I100 is the inductance of the wireless charging device measured at a temperature of 100°C.

4. 4. The wireless charging device according to claim 3, wherein an inductance change rate (ΔID) represented by the following formula 4 is greater than 0 / °C: [Formula 4] Here, the ID4 is expressed by the following Equation 5: [Formula 5] where I25 is the inductance of the wireless charging device measured at a temperature of 25° C. I40 is the inductance of the wireless charging device measured at a temperature of 40°C.

5. A coil portion; a magnetic portion disposed on the coil portion, the magnetic portion includes a polymer type magnetic portion including a binder resin, a filler, and an additive; The additive comprises one or more insulating coating agents selected from the group consisting of phosphoric acid and silane; The content of the insulating coating agent is 2% by weight to 8% by weight based on the total weight of the polymer-type magnetic part, The magnetic portion has a first permeability change rate (ΔP1) represented by the following formula 6 of 0 / ° C. or more. [Formula 6] where P20 is the magnetic permeability of the magnetic part measured at a temperature of 20° C. P0 is the magnetic permeability of the magnetic part measured at a temperature of 0°C.

6. 6. The wireless charging device according to claim 5, wherein the magnetic portion has a second permeability change rate (ΔP2) represented by the following formula 7 of 0 / ° C. or more: [Formula 7] where P20 is the magnetic permeability of the magnetic part measured at a temperature of 20° C. P40 is the magnetic permeability of the magnetic part measured at a temperature of 40°C.

7. The wireless charging device according to claim 5 , wherein the magnetic portion has a maximum value of magnetic permeability at a temperature between 60° C. and 100° C.

8. The wireless charging device according to claim 5, wherein the filler is included in an amount of 60% by weight to 90% by weight based on the total weight of the polymer-type magnetic part, and has an average particle size (D50) of 1 μm to 300 μm.

9. Including a wireless charging device, The wireless charging device includes: A coil portion; a magnetic portion disposed on the coil portion, the magnetic portion includes a polymer type magnetic portion including a binder resin, a filler, and an additive; The additive comprises one or more insulating coating agents selected from the group consisting of phosphoric acid and silane; The content of the insulating coating agent is 2% by weight to 8% by weight based on the total weight of the polymer-type magnetic part, In this case, the wireless charging device has an inductance deviation (ID1) at 80° C., which is expressed by the following Equation 1, of 0 or more: The magnetic portion has a first permeability change rate (ΔP1) represented by the following formula 6 of 0 / °C or more, or A means of transportation that satisfies both: [Formula 1] where I25 is the inductance of the wireless charging device measured at a temperature of 25° C. I80 is the inductance of the wireless charging device measured at a temperature of 80° C. [Formula 6] where P20 is the magnetic permeability of the magnetic part measured at a temperature of 20° C. P0 is the magnetic permeability of the magnetic part measured at a temperature of 0°C.

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