KR102444678B1 - Wireless charging device and vehicle comprising same - Google Patents

Abstract

A wireless charging device according to an embodiment uses two or more different types of hybrid magnetic parts, and by designing their inductances differently, heat generated during wireless charging can be reduced, and charging efficiency can be improved. can In particular, when the composite iron loss (Ci) of the magnetic part is controlled in a specific range by appropriately adjusting the iron loss and inductance of the first magnetic part and the second magnetic part in the hybrid magnetic part, charging efficiency can be maximized, and heat generation can be reduced properties can be further improved.

Description

WIRELESS CHARGING DEVICE AND VEHICLE COMPRISING SAME

The embodiment relates to a wireless charging device and a mobile means comprising the same. More specifically, the embodiment relates to a wireless charging device with improved charging efficiency by applying a heat dissipation structure, and a moving means including the same.

Recently, as interest in electric vehicles has rapidly increased, interest in building charging infrastructure is increasing. Various charging methods such as electric vehicle charging using home chargers, battery replacement, fast charging devices, and wireless charging devices have already appeared, and a new charging business model has also begun to appear (refer to Korean Patent Application Laid-Open No. 2011-0042403). In addition, electric vehicles and charging stations under test operation are starting to stand out in Europe, and in Japan, car manufacturers and electric power companies are piloting electric vehicles and charging stations.

In a conventional wireless charging device used for electric vehicles, etc., a magnetic part is disposed adjacent to a coil part in order to improve wireless charging efficiency, and a shield part (metal plate) for shielding is disposed spaced apart from the magnetic part by a predetermined interval.

The wireless charging device generates heat due to the resistance of the coil part and the magnetic loss of the magnetic part during the wireless charging operation. In particular, the magnetic part in the wireless charging device generates heat near the coil part with high electromagnetic wave energy density, and the generated heat changes the magnetic properties of the magnetic part and causes an impedance mismatch between the transmitting pad and the receiving pad, thereby reducing charging efficiency, As a result, there was a problem in that the heat was intensified again.

In particular, in the conventional wireless charging device, the magnetic part is mainly disposed between the sintered ferrite sheet and the coil part and the shield part, especially on one surface close to the coil part. The sintered ferrite sheet has low impact resistance and heavy specific gravity, and when it is placed close to the coil part, heat is generated from the coil part and the sintered ferrite sheet during charging. Alternatively, it is difficult to transmit and dissipate heat to the spacer part. Accordingly, the sintered ferrite sheet having an elevated temperature may have a problem in that the magnetic properties are lowered and the inductance value of the coil portion is changed accordingly, thereby lowering charging efficiency and causing more severe heat generation.

In order to compensate for the shortcomings of the sintered ferrite sheet, a polymer-type magnetic part with improved impact resistance by mixing magnetic powder with a binder resin can be applied. Therefore, when the magnetic flux is concentrated by being disposed around the coil unit, the temperature continuously increases over time, and the magnetic focusing force is weak, so there may be problems such as a decrease in charging efficiency and generation of high temperature heat generation. In particular, when heat is increased during fast charging and high-power wireless charging, safety issues may limit usability, so it is necessary to develop a wireless charging device capable of simultaneously improving heat reduction characteristics and charging efficiency at high power. to be.

Korean Patent Publication No. 2011-0042403

The present invention is devised to solve the problems of the prior art.

The technical problem to be solved by the present invention includes a hybrid type magnetic part including a different first magnetic part and a second magnetic part disposed adjacent to the first magnetic part, and only the second magnetic part remains. To provide a wireless charging device capable of improving charging efficiency and heat-reducing characteristics during high-power wireless charging by designing the second inductance in , and the first inductance in a state in which only the first magnetic part remains.

Another technical problem to be solved by the present invention is to provide a moving means including the wireless charging device.

According to one embodiment, the coil unit; and a magnetic part disposed on the coil part, wherein the magnetic part comprises: a first magnetic part disposed on the coil part; and a second magnetic part disposed adjacent to the first magnetic part, wherein a second inductance in a state in which only the second magnetic part remains and a first inductance in a state in which only the first magnetic part remains are different from each other, A charging device is provided.

According to another embodiment, including a wireless charging device, the wireless charging device includes a coil unit; and a magnetic part disposed on the coil part, wherein the magnetic part comprises: a first magnetic part disposed on the coil part; and a second magnetic part disposed adjacent to the first magnetic part, wherein a second inductance in a state in which only the second magnetic part remains and a first inductance in a state in which only the first magnetic part remains are different from each other. means are provided.

According to the above embodiment, heat generated during wireless charging can be reduced and charging efficiency can be improved by using two or more different types of hybrid magnetic parts and designing their inductances differently. In particular, when the composite iron loss (Ci) of the magnetic part is controlled in a specific range by appropriately adjusting the iron loss and inductance of the first magnetic part and the second magnetic part in the hybrid magnetic part, charging efficiency can be maximized, and heat generation can be reduced properties can be further improved.

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

1A and 1B are exploded perspective views of a wireless charging device according to an embodiment, respectively.
2A and 2B are perspective views of a wireless charging device according to an embodiment.
3A and 3B are cross-sectional views of a wireless charging device according to an embodiment.
3C to 3E are cross-sectional views of a wireless charging device according to another embodiment.
4 is a schematic diagram showing the outer diameter (Od) of the magnetic portion, the inner diameter (Id) of the magnetic portion, and the thickness (T) of the magnetic portion for measuring the basic iron loss of the magnetic portion.
5 illustrates a process of forming a magnetic part through a mold according to an exemplary embodiment.
6 illustrates a moving means (electric vehicle) having a wireless charging device according to an embodiment.

Hereinafter, specific embodiments for implementing the spirit of the present invention will be described in detail with reference to the drawings.

In addition, in the description of the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

In addition, in the accompanying drawings, some components are exaggerated, omitted, or schematically illustrated, and the size of each component does not fully reflect the actual size.

The terminology used herein is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise.

In this specification, like reference numerals refer to like elements.

In this specification, a component described as being formed above or below another component means that a component is formed directly above or below another component or indirectly through another component. include

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

Also, the meaning of "comprising," as used herein, specifies a particular characteristic, region, integer, step, operation, element and/or component, and other specific characteristic, region, integer, step, operation, element, component and It does not exclude the presence or addition of/or groups.

In addition, it should be understood that all numerical ranges indicating physical property values, dimensions, etc. of the components described in the present specification are modified by the term "about" in all cases unless otherwise specified.

In the present specification, unless otherwise specified, the expression "a" or "a" is interpreted as meaning including the singular or the plural as interpreted in context.

[Wireless Charging Device]

1A and 1B are exploded perspective views of a wireless charging device according to an embodiment, FIGS. 2A and 2B are perspective views of a wireless charging device according to the embodiment, and FIGS. 3A and 3B are wireless charging according to the embodiment A cross-sectional view of each device is shown. In addition, Figures 3c and 3e is a cross-sectional view of a wireless charging device according to another embodiment.

The drawings shown in FIGS. 1 to 3 are illustratively shown according to embodiments, and may be variously changed as long as the effects of the present invention are not impaired.

1A to 1B , a wireless charging device 10 according to an embodiment includes a coil unit 200; a first magnetic part 300 including a magnetic part disposed on the coil part 200 , wherein the magnetic part is disposed on the coil part 200 ; and a second magnetic part 500 disposed adjacent to the first magnetic part 300 , wherein the second inductance and the first magnetic part 300 in a state where only the second magnetic part 500 remains The first inductance in the remaining state is different from each other. In addition, the wireless charging device 10 further includes a support part 100 for supporting the coil part 200 , a shield part 400 disposed on the magnetic part, and a housing 600 for protecting the components. may include

According to the above embodiment, heat generated during wireless charging can be reduced and charging efficiency can be improved by using two or more different types of hybrid magnetic parts and designing their inductances differently.

On the other hand, if two or more types are used in combination as a hybrid type magnetic part, and these magnetic parts are simply stacked without special consideration or disposed without considering their physical properties, magnetic flux is not properly distributed during wireless charging. The heat transfer to the outside is not effective, and it may be easily damaged by an external impact that may be applied while the vehicle is running. In particular, the inductance is a quantity representing a ratio of a counter electromotive force generated by electromagnetic induction by a change in a current flowing through a circuit, and each of these inductances may be an important factor in determining charging efficiency.

According to an embodiment of the present invention, the first inductance means an inductance measured in a state where only the first magnetic part remains in the magnetic part (hybrid magnetic part), and the second inductance is the magnetic part (hybrid type magnetic part). It means the inductance measured in a state where only the second magnetic part remains in the negative part). In particular, when the first inductance and the second inductance are different from each other, charging efficiency can be significantly improved.

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

magnetic part

The wireless charging device according to an embodiment of the present invention includes a hybrid type magnetic part including a first magnetic part and a second magnetic part disposed between the coil part and the shield part.

In the hybrid magnetic part, the first magnetic part includes a polymer-type magnetic block (PMB) including a binder resin and magnetic powder dispersed in the binder resin, and the second magnetic part includes a nanocrystalline magnetic material and a ferritic magnet. At least one may be selected from the group consisting of materials.

The first magnetic portion has high impact resistance and a weight reduction effect, and the second magnetic portion has a strong magnetic focusing force.

In particular, the first magnetic part may have a greater impact resistance than a ferrite-based magnetic material, for example, a ferrite sintered body, and may have a weight reduction effect. However, when only the first magnetic part is used without using the hybrid type magnetic part, the magnetic focusing force (inductance) is weak, and thus charging efficiency may be deteriorated.

On the other hand, although the second magnetic part has a strong magnetic focusing force, it is difficult to process a plate enlargement, and there may be restrictions in manufacturing and processing in the form of a thick film for automobiles.

Accordingly, the performance of the wireless charging device can be efficiently improved by using the second magnetic part having a strong magnetic focusing force together with the first magnetic part having high impact resistance and a weight reduction effect.

In the hybrid magnetic part, a second inductance in a state in which only the second magnetic part remains and a first inductance in a state in which only the first magnetic part remains may be different from each other.

According to the above embodiment, heat generated during wireless charging can be reduced and charging efficiency can be improved by using two or more different types of hybrid magnetic units and designing their inductances differently.

In addition, when the hybrid type magnetic part is used, the charging efficiency may be further improved by lowering the composite iron loss (Ci) of the magnetic part.

In addition, in the hybrid magnetic part, since the first magnetic part and the second magnetic part have different inductances, magnetic characteristics, and calorific value, heat can be effectively radiated to the outside according to a method of arranging and combining them.

In the wireless charging device according to an embodiment of the present invention, the composite iron loss (Ci) of the magnetic part represented by Equation 1 below may be 1200 W/m 3 or less:

[Equation 1]

Ci = 0.51 × Lt × (a/La + c/Lc)

In Equation 1 above,

a is the iron loss per unit of measurement of the second magnetic part,

c is the iron loss per unit of measurement of the first magnetic part,

Lt is the inductance measured in a state in which the first magnetic part and the second magnetic part are mounted,

La is the second inductance,

Lc is the first inductance.

In the present invention, the composite iron loss (Ci) means the sum of all losses occurring in the magnetic part, that is, the investment loss and other losses, which may mean the basic intrinsic characteristics of the magnetic part. Since the iron loss generally refers to a portion that generates heat in the iron core, various structural methods such as improving a magnetic material or stacking thin pieces insulated from each other have been devised to reduce the iron loss as much as possible.

Accordingly, the present invention applies a hybrid type magnetic part including two different types of magnetic parts in order to lower an amount of loss occurring in the magnetic part, that is, iron loss.

However, in the case of using the hybrid type magnetic part as in the present invention, the calculated iron loss, that is, the composite iron loss (Ci), is used instead of the intrinsic iron loss when each magnetic part is used alone. That is, in the case of using a hybrid magnetic part, the composite iron loss (Ci) expressed by Equation 1 should be used because it is affected by the thickness, volume, and inductance of the composite magnetic part.

According to an embodiment of the present invention, when a polymer type magnetic block (PMB) is used as the first magnetic part, the intrinsic iron loss of the PMB may be large in the same magnetic field, but the first magnetic part is applied together with the second magnetic part. In the case of using a hybrid magnetic part, it is important to control the composite iron loss (Ci) in a specific range because magnetic properties such as magnetic permeability and investment loss of the hybrid magnetic part are different.

Since the composite iron loss (Ci) means iron loss per unit volume, the unit is W/m3.

The composite iron loss (Ci) is 1200 W/m3 or less, 1190 W/m3 or less, 1180 W/m3 or less, 1100 W/m3 or less, 1050 W/m3 or less, 1000 W/m3 or less, 900 W/m3 or less, 800 W/m3 or less, 700 W/m3 or less, or 650 W/m3 or less. The composite iron loss (Ci) may be 90 W/m3 or more, 100 W/m3 or more, 120 W/m3 or more, 150 W/m3 or more, 180 W/m3 or more, or 200 W/m3 or more.

When the composite iron loss (Ci) of the magnetic part satisfies the above range, charging efficiency and heat reduction characteristics may be efficiently improved. If the composite iron loss (Ci) is out of the above range, heat generation may increase and energy loss may increase, thereby reducing charging efficiency.

In addition, the composite iron loss (Ci) in the magnetic part may vary depending on the type of the second magnetic part.

According to one embodiment of the present invention, in the wireless charging device, the second magnetic part may include a nanocrystalline magnetic material, and the composite iron loss (Ci) may be greater than 700 W/m 3 and less than or equal to 1200 W/m 3 . Specifically, in the wireless charging device, the second magnetic part includes a nanocrystalline magnetic material, and the composite iron loss (Ci) is greater than 800 W/m 3 to 1200 W/m 3 or less, 900 W/m 3 to 1200 W/m m3 or less, 1000 W/m3 or more to 1200 W/m3 or less, 1110 W/m3 or more to 1200 W/m3 or less, 1110 W/m3 or more to 1200 W/m3 or less, 1115 W/m3 or more to 1200 W/m3 or less , 1120 W/m 3 or more and 1200 W/m 3 or less, or 1120 W/m 3 or more and 1190 W/m 3 or less.

When the second magnetic part includes a nanocrystalline magnetic material and the composite iron loss (Ci) satisfies the above range, charging efficiency and heat reduction characteristics may be efficiently improved. If the composite iron loss (Ci) is too high, heat may occur and charging efficiency may decrease.

According to another embodiment of the present invention, the second magnetic part may include a ferritic magnetic material, and the composite iron loss (Ci) may be 300 W/m 3 or more and less than 1120 W/m 3 .

Specifically, the second magnetic part includes a ferritic magnetic material, and the composite iron loss (Ci) is 300 W/m 3 to 1115 W/m 3, 300 W/m 3 to 1100 W/m 3, 300 W/m 3 to 1000 W /m3, 300 W/m3 to 800 W/m3, 300 W/m3 to 700 W/m3, 350 W/m3 to 700 W/m3, 350 W/m3 to 650 W/m3, 400 W/m3 to 650 W /m 3 , or 450 W/m 3 to 630 W/m 3 . When the second magnetic part includes a ferritic magnetic material and the composite iron loss (Ci) satisfies the above range, charging efficiency and heat reduction characteristics may be efficiently improved.

If, as the magnetic part in the wireless charging device, the first magnetic part, not the hybrid-type magnetic part, is used alone, the polymer type magnetic block may excessively increase the iron loss to 2000 W/m 3 or more, resulting in a sharp decrease in charging efficiency.

However, according to the embodiment of the present invention, when the polymer type magnetic block, which is the first magnetic unit having an iron loss of 2000 W/m3 or more, is used together with the second magnetic unit to form a hybrid magnetic unit, the iron loss of the magnetic unit is 1200 W/m3 Below, there is an advantage that it can be lowered to a maximum of 650 W/m3 or less. In this case, heat reduction characteristics and charging efficiency can be maximized.

In addition, when a ferritic magnetic material, which is a second magnetic part, not a hybrid magnetic part, is used alone as a magnetic part in a wireless charging device, the iron loss can be lowered to 100 W/m3 or less, so charging efficiency can be improved, but the saturation There is a problem in increasing the capacity due to the low magnetic flux density.

The composite iron loss (Ci) expressed by Equation 1 may be affected by the thickness and volume of the magnetic part. For example, when a first magnetic part having a large iron loss is used in the same magnetic field and the thickness thereof is large, it may appear that the iron loss is low because the volume increases due to the thickness. For example, when the thickness of the first magnetic part increases from 1 mm to 4 mm, the iron loss may appear to decrease. Therefore, the correction constant in Equation 1 is used.

The correction constant used according to the embodiment of the present invention is 0.51, which is a correction constant calculated in consideration of the thickness and volume of the first magnetic part and the second magnetic part when using the hybrid type magnetic part. In addition, if the volume is the same in the magnetic part, the inductance may be the same. The volume range of the magnetic part may be in the range of 100 cm 3 to 1700 cm 3 .

The composite iron loss Ci may be measured using basic measurement iron loss (core loss per unit of measurement of the first magnetic portion or the second magnetic portion) and inductance of each magnetic part.

A and c are basic measured iron losses, which mean iron loss per measurement unit of the second magnetic part and iron loss per measurement unit of the first magnetic part, respectively.

The a and c are, with reference to FIG. 4, the first magnetic part and the second magnetic part having an outer diameter (Ot) of 50 mm, an inner diameter (It) of 30 mm, and a thickness (T) of 4 mm B-H at 100 kHz and 100 mT, respectively It can be measured with a meter (B-H Anlyzer). Specifically, after measuring the dimensions and weight of the magnetic part of the wireless charging device, calculating the relative density, and measuring the strength of the wireless charging device, DC magnetization and magnetic flux density 0.1 T, frequency using a DC and AC B-H meter It is possible to measure the basic measurement iron loss at 100 kHz.

The a may be 500 W/m 3 or less. Specifically, a may be 400 W/m 3 or less, 300 W/m 3 or less, 250 W/m 3 or less, 220 W/m 3 or less, 200 W/m 3 or less, 150 W/m 3 or less, or 100 W/m 3 or less. The a may be 30 W/m 3 or more, 50 W/m 3 or more, 60 W/m 3 or more, 70 W/m 3 or more, 80 W/m 3 or more, 85 W/m 3 or more, or 90 W/m 3 or more.

According to an embodiment of the present invention, when a ferritic magnetic material is used as the second magnetic part, a is 200 W/m3 or less, 150 W/m3 or less, or 100 W/m3 or less, or 100 W/m3 or less, in Equation 1 as a basic measurement iron loss. m3 or less. The a may be 30 W/m 3 or more, 50 W/m 3 or more, 60 W/m 3 or more, 70 W/m 3 or more, or 80 W/m 3 or more. The a may be, for example, 30 W/m 3 to 200 W/m 3 , 50 W/m 3 to 150 W/m 3 , or 50 W/m 3 to 100 W/m 3 .

According to an embodiment of the present invention, when a nanocrystalline magnetic material is used as the second magnetic part, a in Equation 1 as a basic measurement iron loss is 500 W/m 3 or less, 400 W/m 3 or less, 300 W/m 3 or less. or less, 250 W/m3 or less, and 220 W/m3 or less. The a may be 50 W/m 3 or more, 90 W/m 3 or more, 100 W/m 3 or more, 120 W/m 3 or more, 150 W/m 3 or more, 180 W/m 3 or more. The a may be, for example, 50 W/m 3 to 500 W/m 3 , 100 W/m 3 to 400 W/m 3 , or 150 W/m 3 to 250 W/m 3 .

c is the iron loss per unit of measurement of the first magnetic part (basic measured iron loss) measured using a B-H meter at 100 kHz and 100 mT of the first magnetic part having an outer diameter of 50 mm, an inner diameter of 30 mm, and a thickness of 4 mm. The c may be 500 W/m 3 or more. Specifically, c may be 600 W/m 3 or more, 800 W/m 3 or more, 900 W/m 3 or more, 1000 W/m 3 or more, 1100 W/m 3 or more, 1500 W/m 3 or more, or 1800 W/m 3 or more. The c may be 5000 W/m 3 or less, 4500 W/m 3 or less, 4000 W/m 3 or less, 3500 W/m 3 or less, 3000 W/m 3 or less, or 2500 W/m 3 or less. c may be 500 W/m 3 to 5000 W/m 3 or 1000 W/m 3 to 3000 W/m 3 .

Lt is the total inductance of the hybrid type magnetic part, and is the inductance measured when the first magnetic part and the second magnetic part are mounted. The Lt may be 25 to 60 μH. The Lt may be 30 to 55 μH, 35 to 50 μH, 38 to 50 μH, 40 μH to 45 μH, 42 μH to 45 μH, or greater than or equal to 42 μH and less than 44 μH.

La is the second inductance, and is an inductance measured in a state in which only the second magnetic part remains in the hybrid type magnetic part. For example, La may measure the inductance after replacing the first magnetic part with an empty space or a spacer part. The La may be 35 to 60 μH. The La may be 35 to 55 μH, 40 to 50 μH, 40 to 48 μH, 38 to 43 μH, or 42 to 47 μH.

Lc is the inductance of the first magnetic part, and is an inductance measured in a state in which only the first magnetic part remains in the hybrid type magnetic part. For example, the Lc may measure the inductance after replacing the second magnetic part with an empty space or a spacer part. The Lc may be 35 to 55 μH. The Lc may be 35 to 50 μH, 37 to 50 μH, 35 to 48 μH, 35 to 45 μH, or 37 to 44 μH.

The inductance is a conversion constant that converts a current into a magnetic flux, and when the magnetic flux is constant, the inductance and the current are in inverse proportion. In the present invention, the inductance was measured using an LCR Meter (IM3533, HIOKI Corporation).

In Equation 1, Lt may be 25 to 60 μH, La may be 35 to 60 μH, and Lc may be 35 to 55 μH. According to an embodiment of the present invention, the first inductance (Lc) and the second inductance (La) are different from each other. That is, La and Lc each have different values within the above range.

When Lt, La, and Lc satisfy the above range and La and Lc have different values, the composite iron loss (Ci) of the magnetic part desired in the present invention may be satisfied, so charging efficiency and heat reduction characteristics can improve If the Lt, La, and Lc are out of the above ranges or have the same values, heat generation may occur and charging efficiency may decrease.

Meanwhile, in Equation 1, a/La, which is an iron loss (a) per unit of measurement of the second magnetic part with respect to the second inductance La, may be 1 W/m 3 to 8 W/m 3 . The a/La may be 2 W/m3 to 6 W/m3, or 2 W/m3 to 5 W/m3.

In Equation 1, c/Lc, which is an iron loss c per unit of measurement of the first magnetic part with respect to the first inductance Lc, may be 20 W/m 3 to 100 W/m 3 . The c/Lc may be 20 W/m 3 to 80 W/m 3 , 20 W/m 3 to 60 W/m 3 or 25 W/m 3 to 50 W/m 3 .

When a/La or c/Lc is satisfied in Equation 1, charging efficiency and heat reduction characteristics may be improved.

Meanwhile, the hybrid type magnetic part of the present invention may have different types of the first magnetic part and the second magnetic part, and may have different calorific values.

According to an exemplary embodiment of the present invention, a second magnetic part having a larger heating value during wireless charging than the first magnetic part among the magnetic parts may be disposed closer to the shield part.

For example, when two types of hybrid magnetic units with different calorific values are used, the magnetic flux that is focused during wireless charging can be distributed in a desired direction, and in particular, more during wireless charging compared to the first magnetic unit among the magnetic units. By disposing the second magnetic part having a large heating value close to the shield part, the magnetic flux density and heat radiation are effectively distributed to increase the wireless charging efficiency, and the heat generated from the second magnetic part is emitted through the shield part to efficiently dissipate the heat dissipation characteristics. can be improved

1a and 1b respectively show a configuration diagram of a wireless charging device according to an embodiment of the present invention.

1A is a configuration diagram of a wireless charging device 10 according to an embodiment of the present invention, and is an example of a structure (planar structure) in which a first magnetic part 300 and a second magnetic part 500 are sequentially stacked. , Figure 1b is a block diagram of the wireless charging device 10 according to another embodiment of the present invention, the first magnetic unit 300 has a three-dimensional structure, the second magnetic unit 500 is a coil unit corresponding to This is an example placed only in the area.

1A and 1B, the wireless charging device 10 according to an embodiment includes a coil unit 200; a first magnetic part 300 including a magnetic part disposed on the coil part 200 , wherein the magnetic part is disposed on the coil part 200 ; and a second magnetic part 500 disposed adjacent to the first magnetic part 300 . In this case, the second magnetic part 500 may be disposed on the first magnetic part 300 . In addition, the second magnetic unit 500 may have a greater heat output during wireless charging and may be disposed close to the shield unit 400 .

In addition, the first magnetic unit 300 may include an outer portion 310 corresponding to a portion where the coil unit 200 is disposed; and a central portion 320 surrounded by the outer portion 310 , wherein a thickness of the outer portion 310 may be greater than a thickness of the central portion 320 . In this case, in the first magnetic part, the outer part and the central part may be integrally formed with each other. Alternatively, in the first magnetic part, the outer part 310 and the central part 320 may have the same thickness.

In addition, a thickness of a region corresponding to the coil unit 200 in the first magnetic unit 300 may be greater than a thickness of a region corresponding to the coil unit 200 in the second magnetic unit 500 . .

The total thickness of the first magnetic part and the second magnetic part is 1 mm to 15.0 mm, 1.02 mm to 15.0 mm, 1.02 mm to 13.0 mm, 1.05 mm to 13.0 mm, 3.0 mm to 12.0 mm, 4.0 mm to 11.0 mm, 5.0 mm to 10.5 mm, 5.0 mm to 8.0 mm or greater than 8.0 mm to 10.5 mm or less. When the total thickness of T1 and T2 is too large, the weight of the magnetic part may increase, and thus there may be restrictions on the process or use.

In addition, a thickness ratio of the first magnetic part and the second magnetic part may be 1: 0.01 to 0.6, 1: 0.03 to 0.5, or 1: 0.05 to 0.4. In this case, the thickness ratio is based on the outermost portion, which is a region corresponding to the coil portion.

Thermal conductivity of the second magnetic part may be higher than that of the first magnetic part by 0.1 W/m.K to 6 W/m.K, 0.5 W/m.K to 5 W/m.K, or 1 W/m.K to 4 W/m.K. By disposing the second magnetic part, which has higher thermal conductivity than the first magnetic part, adjacent to the shield part, the heat generated during wireless charging is effectively dispersed through the distribution of magnetic flux, and the durability against external shock or distortion can be improved. have.

In addition, by adjusting the amount (volume) used for each magnetic part in consideration of the magnetic properties and physical properties of the two types of magnetic parts, it is possible to improve the impact resistance and reduce the manufacturing cost without impairing charging efficiency. For example, the first magnetic part may have a volume 2 to 9.5 times larger than that of the second magnetic part.

For example, the volume ratio of the first magnetic part and the second magnetic part may be 1: 0.01 to 0.6, 1: 0.03 to 0.5, or 1: 0.05 to 0.4.

Hereinafter, the first magnetic part and the second magnetic part will be described in detail.

first magnetic part

Type of first magnetic part

The magnetic part according to an embodiment of the present invention may include a first magnetic part, and the first magnetic part may include a polymer-type magnetic block (PMB) including a binder resin and magnetic powder dispersed in the binder resin. The first magnetic part includes a polymer-type magnetic block and magnetic powders are combined with each other by a binder resin, so that overall there are fewer defects in a large area, less damage by impact, excellent impact resistance, weight reduction, etc. can

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

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

[Formula 1]

Fe _1-abc Si _a X _b Y _c

wherein X is Al, Cr, Ni, Cu, or a combination thereof; Y is Mn, B, Co, Mo, or a combination thereof; 0.01 ≤ a ≤ 0.2, 0.01 ≤ b ≤ 0.1, and 0 ≤ c ≤ 0.05.

The average particle diameter of the magnetic powder may be in the range of about 3 nm to about 1 mm, about 1 μm to 300 μm, about 1 μm to 50 μm, or about 1 μm to 10 μm.

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

For example, the first magnetic portion contains 10 wt% to 99 wt%, 10 wt% to 95 wt%, 50 wt% to 95 wt%, 50 wt% to 92 wt%, 70 wt% to 95 wt% of the magnetic powder. weight %, 80% to 95% by weight, or 80% to 90% by weight.

As the binder resin, polyimide resin, polyamide resin, polycarbonate resin, acrylonitrile-butadiene-styrene (ABS) resin, polypropylene resin, polyethylene resin, polystyrene resin, polyphenylsulfide (PSS) resin, polyether ether ketone (PEEK) resin, silicone resin, acrylic resin, polyurethane resin, polyester resin, isocyanate resin, epoxy resin and the like may be exemplified, but is not limited thereto.

For example, the binder resin may be a curable resin. Specifically, the binder resin may be a photocurable resin and/or a thermosetting resin, and in particular, may be a resin capable of exhibiting adhesiveness by curing. More specifically, the binder resin includes at least one functional group or site that can be cured by heat, such as a glycidyl group, an isocyanate group, a hydroxyl group, a carboxyl group, or an amide group; or at least one functional group or moiety that can be cured by active energy such as an epoxide group, a cyclic ether group, a sulfide group, an acetal group, or a lactone group resin can be used. Such a functional group or moiety may be, for example, an isocyanate group (-NCO), a hydroxyl group (-OH), or a carboxyl group (-COOH).

The first magnetic part may contain the binder resin in an amount of 5 wt% to 40 wt%, 5 wt% to 20 wt%, 5 wt% to 15 wt%, or 7 wt% to 15 wt%.

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

Structural features of the first magnetic part

The first magnetic part is disposed between the coil part and the shield part.

The first magnetic part is disposed on the coil part.

In addition, the first magnetic part may be disposed to be spaced apart from the coil part by a predetermined interval. For example, the separation distance between the first magnetic part and the coil part may be 0.2 mm or more, 0.5 mm or more, 0.2 mm to 3 mm, or 0.5 mm to 2 mm.

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

According to an embodiment of the present invention, the first magnetic part may have a three-dimensional structure, and in this case, charging efficiency and heat dissipation characteristics may be improved.

3B, 3C, and 3E, the first magnetic part 300 includes an outer part 310 corresponding to a part where the coil part 200 is disposed; and a central portion 320 surrounded by the outer portion 310 , wherein a thickness of the outer portion 310 may be greater than a thickness of the central portion 320 . In this case, in the first magnetic part, the outer part and the central part may be integrally formed with each other.

As described above, by increasing the thickness of the magnetic part near the coil where electromagnetic energy is concentrated during wireless charging and lowering the thickness of the central magnetic part having a relatively low electromagnetic energy density because there is no coil, the electromagnetic wave concentrated around the coil is effectively focused and charged. In addition to improving efficiency, it is possible to firmly maintain a distance between the coil unit and the shield unit without a separate spacer unit, thereby reducing material and process costs due to the use of the spacer unit.

In the first magnetic part, the outer part may have a thickness that is 1.5 times or more thicker than that of the central part. When the thickness ratio is, the magnetic field concentrated around the coil can be more effectively focused to improve charging efficiency, and it is also advantageous for heat generation and weight reduction. Specifically, in the first magnetic part, the thickness ratio of the outer part/central part may be 2 or more, 3 or more, or 5 or more. In addition, the thickness ratio may be 100 or less, 50 or less, 30 or less, or 10 or less. More specifically, the thickness ratio may be 1.5 to 100, 2 to 50, 3 to 30, or 5 to 10.

The thickness of the outer portion of the first magnetic part may be 2 mm or more, 3 mm or more, or 5 mm or more, and may be 30 mm or less, 20 mm or less, or 11 mm or less. In addition, the thickness of the center of the first magnetic part may be 10 mm or less, 7 mm or less, or 5 mm or less, and may be 0 mm, 0.1 mm or more, or 1 mm or more. Specifically, the outer portion of the first magnetic portion may have a thickness of 2 mm to 12 mm, and the central portion may have a thickness of 0 mm to 5 mm.

When the thickness of the central part 320 of the first magnetic part 300 is 0, the first magnetic part 300 may have an empty shape in the central part 320 (eg, a donut shape). In this case, the charging efficiency can be effectively improved even with a smaller area of the first magnetic part.

Also, according to an exemplary embodiment, the first magnetic part may have a planar structure (see FIGS. 3A and 3D ) rather than a three-dimensional structure. That is, in the first magnetic part, the outer part and the central part may have the same thickness.

Meanwhile, the first magnetic part may have a large area, and specifically, may have an area of 200 cm ² or more, 400 cm ² or more, or 600 cm ² or more. Also, the first magnetic part may have an area of 10,000 cm ² or less.

The large-area first magnetic part may be configured by combining a plurality of unit magnetic parts, and in this case, the area of the unit magnetic part may be 60 cm ² or more, 90 cm ² , or 95 cm ² to 900 cm ² .

Meanwhile, the volume of the first magnetic part may be 100 cm 3 to 1500 cm 3 . In addition, the volume of the first magnetic part may be 200 cm 3 to 1200 cm 3 , 300 cm 3 to 1100 cm 3 , or 400 cm 3 to 1100 cm 3 .

The first magnetic part may be a magnetic block manufactured by a method such as molding through a mold. For example, the first magnetic part may be molded into a three-dimensional structure through a mold. The magnetic sheet may be molded into a three-dimensional structure by mixing magnetic powder and a binder resin and injecting it into a mold by injection molding or the like.

Specifically, the molding may be performed by injecting the raw material of the magnetic part into the mold by injection molding. More specifically, the magnetic part obtains a raw material composition 701 by mixing magnetic powder and a polymer resin composition, and then, as shown in FIG. 5 , the raw material composition 701 is applied to a mold 703 by an injection molding machine 702. It can be prepared by injection. In this case, by designing the internal shape of the mold 703 as a three-dimensional structure, the three-dimensional structure of the magnetic part can be easily implemented. Such a process may be difficult when an existing sintered ferrite sheet is used as a magnetic part.

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

Specifically, the magnetic sheet stack may be one in which one or more additional magnetic sheets are further stacked only at the center of the first magnetic part. In this case, the individual magnetic sheet may have a thickness of 80 μm or more, or 85 μm to 150 μm. Such a magnetic sheet may be manufactured by a conventional sheet forming process, such as mixing magnetic powder and a binder resin to form a slurry, then forming and curing the magnetic sheet into a sheet shape.

Magnetic properties of the first magnetic part

The first magnetic part may have a magnetic characteristic of a certain level in the vicinity of the wireless charging standard frequency of the electric vehicle.

The wireless charging standard frequency of the electric vehicle may be less than 100 kHz, for example, 79 kHz to 90 kHz, specifically 81 kHz to 90 kHz, more specifically about 85 kHz, which is a mobile electronic device such as a mobile phone. It is a band distinct from the applied frequency.

In the frequency band of 85 kHz of the first magnetic part, the magnetic permeability may vary depending on the material, and may be in the range of 5 to 150,000, and depending on the specific material, 10 to 30,000, 10 or more to 1,000 or less, 1,000 to 8,000 or less, 8,000 greater than and up to 30,000, or from 50 to 200. In addition, the investment loss in the 85 kHz frequency band of the first magnetic part may vary depending on the material, and may be 0 to 50,000 in a wide range, and 0 to 1,000, 1 to 100, 100 to 1,000, or 5,000 to 1,000 depending on the specific material. It can be 50,000.

As a specific example, when the first magnetic part is a polymer-type magnetic block including a magnetic powder and a binder resin, the magnetic permeability in the frequency band of 85 kHz is 5 to 500, or 50 to 200, 50 to 130, 55 to 120, or It may be 10 to 50, and the investment loss may be 0 to 50, 0 to 20, 0 to 15, or 0 to 5.

Physical properties of the first magnetic part

The first magnetic part may be elongated at a certain rate. For example, the elongation of the first magnetic part may be 0.5% or more. The elongation property is difficult to obtain in a ceramic magnetic part to which a polymer is not applied, and damage can be reduced even when a large-area magnetic part is distorted due to an impact. Specifically, the elongation of the first magnetic part may be 0.5% or more, 1% or more, or 2.5% or more. There is no particular limitation on the upper limit of the elongation, but if the content of the polymer resin is increased to improve the elongation, properties such as inductance of the magnetic part may be deteriorated, so that the elongation is preferably 10% or less.

The first magnetic part has a small rate of change in characteristics before and after impact, and is significantly superior to that of a general ferrite magnetic sheet.

In the present specification, the characteristic change rate (%) before and after the impact of a certain characteristic may be calculated by the following formula.

Characteristic change rate (%) = | Property Values Before Impact - Property Values After Impact | / property value before impact x 100

For example, the inductance change rate before and after the impact applied by free-falling from a height of 1 m to the first magnetic part may be less than 5%, or less than 3%. More specifically, the inductance change rate may be 0% to 3%, 0.001% to 2%, or 0.01% to 1.5%. When it is within the above range, the inductance change rate before and after the impact is relatively small, so that the stability of the magnetic part may be further improved.

In addition, the first magnetic part may be free-falling from a height of 1 m and a change rate of a quality factor (Q factor) before and after the applied impact may be 0% to 5%, 0.001% to 4%, or 0.01% to 2.5%. When it is within the above range, there is little change in characteristics before and after the impact, so that the stability and impact resistance of the magnetic part may be further improved.

In addition, the resistance change rate before and after the impact applied by free-falling from a height of 1 m to the first magnetic part may be 0% to 2.8%, 0.001% to 1.8%, or 0.1% to 1.0%. When it is within the above range, the resistance value may be well maintained below a certain level even if it is repeatedly applied in an environment to which an actual shock and vibration are applied.

In addition, the charge efficiency change rate before and after the impact applied by free-falling from a height of 1 m to the first magnetic part may be 0% to 6.8%, 0.001% to 5.8%, or 0.01% to 3.4%. When it is within the above range, the characteristics of the large-area magnetic part may be more stably maintained even if impact or distortion occurs repeatedly.

second magnetic part

Type of second magnetic part

The magnetic part according to an embodiment of the present invention includes a second magnetic part.

The second magnetic part may include a ferritic magnetic material, a nanocrystalline magnetic material, or a combination thereof. The second magnetic part may be a ferritic magnetic material, and specifically, may include an oxide-based magnetic material, a metal-based magnetic material, or a composite material thereof.

According to the embodiment of the present invention, by using a material having a strong magnetic focusing force as the second magnetic portion, the disadvantage of the first magnetic portion, which may cause a decrease in charging efficiency due to a weak magnetic focusing force (inductance), can be compensated. have.

If only the first magnetic part is used without the second magnetic part, there may be effects such as impact resistance and weight reduction, but the magnetic focusing force (inductance) may be weak, and thus charging efficiency may be deteriorated. On the other hand, although the second magnetic part has a strong magnetic focusing force, it is difficult to process a plate enlargement, and there may be restrictions in manufacturing and processing in the form of a thick film for automobiles. Accordingly, the performance of the wireless charging device can be efficiently improved by using the second magnetic part having a strong magnetic focusing force together with the first magnetic part having high impact resistance and a weight reduction effect.

The oxide-based magnetic material may be a ferrite-based material, and a specific chemical formula may be expressed as MOFe ₂ O ₃ (where M is one or more divalent metal elements such as Mn, Zn, Cu, and Ni). The ferritic material is advantageous in terms of magnetic properties such as magnetic permeability that it is a sintered body. The ferritic material may be manufactured in the form of a sheet or block by mixing raw materials, calcining, pulverizing, mixing this with a binder resin, molding, and firing.

More specifically, the oxide-based magnetic material may be a Ni-Zn-based, Mg-Zn-based, or Mn-Zn-based ferrite, and in particular, the Mn-Zn-based ferrite is a Mn-Zn-based ferrite over a temperature range of room temperature to 100° C. or higher at a frequency of 85 kHz. It can exhibit high magnetic permeability, low investment loss, and high saturation magnetic flux density.

The Mn-Zn-based ferrite is iron oxide Fe ₂ O ₃ 66 mol% to 70 mol%, ZnO 10 mol% to 20 mol%, MnO 8 mol% to 24 mol%, NiO 0.4 mol% to 2 mol% as a main component. and SiO ₂ , CaO, Nb ₂ O ₅ , ZrO ₂ , SnO and the like as other subcomponents. The Mn-Zn-based ferrite is pulverized by mixing the main component in a predetermined molar ratio, calcining in the air at a temperature of 800°C to 1100°C for 1 hour to 3 hours, and then adding subcomponents, and thus a binder such as polyvinyl alcohol (PVA) After mixing an appropriate amount of resin and press-molding using a press, the temperature is raised to 1200° C. to 1300° C. and calcined for 2 hours or more, thereby producing a sheet or block form. Then, it is cut to a required size through processing using a wire saw or a water jet, if necessary.

In addition, the metal-based magnetic material may be a Fe-Si-Al alloy magnetic material or a Ni-Fe alloy magnetic material, and more specifically, sandust (sendust) or permalloy (permalloy).

In addition, the second magnetic part may include a nanocrystalline magnetic material, for example, a Fe-based nanocrystalline magnetic material, specifically, a Fe-Si-Al-based nanocrystalline magnetic material, Fe-Si-Cr It may include a nanocrystalline magnetic material based on, or a magnetic nanocrystalline material based on Fe-Si-B-Cu-Nb. When the nanocrystalline magnetic material is applied to the second magnetic part, the higher the distance from the coil part, the lower the resistance (Rs) even if the inductance (Ls) of the coil part is lowered, so that the quality factor (Q factor) of the coil part : Ls/Rs) increases, so charging efficiency can be improved and heat generation can be reduced.

The second magnetic part may be made of a magnetic material different from that of the first magnetic part. As a specific example, the first magnetic part includes a Fe-Si-Al-based alloy magnetic material, and the second magnetic part includes Mn-Zn-based ferrite, Fe-Si-Al-based nanocrystalline magnetic powder, and Fe-Si-Cr. It may include at least one selected from the group consisting of a nanocrystalline magnetic powder based on nanocrystalline and Fe-Si-B-Cu-Nb based nanocrystalline magnetic powder. The combination of the first magnetic part and the second magnetic part is advantageous in that the second magnetic part has a higher magnetic permeability at 85 kHz than the first magnetic part.

Structural features of the second magnetic part

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

In addition, the thickness of the second magnetic part may be 0.04 mm to 5 mm, 0.1 mm to 5 mm, 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. may be mm.

In addition, the volume of the second magnetic portion may be 1 cm 3 to 900 cm 3 , 6 cm 3 to 550 cm 3 , or 12 cm 3 to 440 cm 3 .

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

For example, the second magnetic part may have the same large area as the first magnetic part. Specifically, the area of the second magnetic part may be 200 cm ² or more, 400 cm ² or more, or 600 cm ² or more. Also, the area of the second magnetic part may be 10,000 cm ² or less.

Alternatively, the second magnetic part may have a smaller area than the first magnetic part. For example, when the second magnetic portion is disposed only on the outer portion of the first magnetic portion, the second magnetic portion may have an area corresponding to the area of the outer portion. Also, according to this, the second magnetic part may be disposed at a position corresponding to the coil part, and may have an area corresponding to the area of the coil part. In this case, the second magnetic part can effectively improve charging efficiency and heat dissipation characteristics even with a small area.

Magnetic properties of the second magnetic part

The second magnetic part may have a magnetic characteristic in a specific range near the wireless charging standard frequency of the electric vehicle.

For example, the magnetic permeability in the 85 kHz frequency band of the second magnetic part may vary depending on the material, and may have a magnetic permeability of 10 to 150,000 broadly.

The magnetic permeability of the second magnetic part may be 10 or more to 30,000 or less, 10 or more to 1,000 or less, 1,000 or more to 8,000 or less, or 8,000 or more to 30,000 or less.

The magnetic permeability of the second magnetic part may be greater than that of the first magnetic part.

In addition, the magnetic permeability of the second magnetic part may be 500 to 20,000, 1,000 to 20,000, 500 to 3,500, 1,000 to 5,000, 5,000 to 20,000, 10,000 to 100,000, or 8,000 to 150,000 depending on specific materials.

In addition, the investment loss in the 85 kHz frequency band of the second magnetic part may vary depending on the material, and may be 0 to 50,000 in a wide range, and 0 to 1,000, 1 to 100, 100 to 1,000, or 5,000 to 1,000 depending on the specific material. It can be 50,000.

As a specific example, the second magnetic part may have a magnetic permeability of 1,000 to 20,000 at 85 kHz, and an investment loss of 0 to 500.

As a specific example, when the second magnetic part is a ferritic magnetic material, the magnetic permeability in a frequency band of 85 kHz may be 1,000 to 5,000, more than 1,000 to less than 5,000, 2,000 to 5,000 or 2,000 to 4,000, and the investment loss is 0 to 1,000, 0 to 500, 0 to 100, or 0 to 50.

As another example, when the second magnetic part is a nanocrystalline magnetic material, the magnetic permeability in the frequency band of 85 kHz is 5,000 or more, 5,000 to 180,000, 5,000 to 180,000, 12,000 to 18,000, 13,000 to 17,000, 14,000 to 16,000 can have a permeability of In addition, the investment loss may be 100 to 50,000, or 1,000 to 10,000.

arrangement of the second magnetic part

3A to 3E , the second magnetic part 500 may be disposed adjacent to the first magnetic part 300 .

Specifically, by disposing a second magnetic part having a higher magnetic permeability at 85 kHz than the first magnetic part among the hybrid magnetic parts adjacent to the first magnetic part disposed on the coil part, charging efficiency and heat dissipation characteristics can be improved. have.

In addition, the second magnetic part 500 is disposed between the shield part 400 and the first magnetic part 300 , and the second magnetic part 500 is thermally connected to the shield part 400 . and may be electrically insulated.

In addition, the second magnetic part 500 may have a higher magnetic permeability at 85 kHz than the first magnetic part 300 , and may be disposed close to the shield part 400 .

As described above, by disposing the second magnetic part having a higher magnetic permeability than the first magnetic part close to the shield part, high magnetic flux density around the coil part can be effectively dispersed, so that when the first magnetic part is used alone As compared to , it is possible to not only increase the charging efficiency but also effectively dissipate heat that is concentrated in the vicinity of the coil part of the first magnetic part.

Also, at least a portion of the second magnetic part may contact the shield part. Accordingly, heat generated from the second magnetic part may be effectively discharged through the shield part. For example, when the second magnetic part is in the form of a sheet, an entire surface of the second magnetic part may contact the shield part. The second magnetic part may be attached to one surface of the shield part with 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.

In addition, as shown in FIG. 3A , the second magnetic part 500 is located in both the outer part 310 corresponding to the coil part 200 and the central part 320 surrounded by the outer part 310 . can be deployed

Also, as shown in FIGS. 3B to 3E , the second magnetic part 500 may be disposed only in the outer part 310 corresponding to the coil part 200 . Accordingly, a high magnetic flux density around the coil part can be effectively dispersed, and thus charging efficiency can be increased compared to the case where the first magnetic part is used alone.

Alternatively, the second magnetic part may be disposed over at least a portion of the outer part and the central part.

The second magnetic part may be disposed to be coupled to or separated from the first magnetic part.

Meanwhile, the second magnetic part may also contact the first magnetic part. For example, the second magnetic part may be attached to an outer portion of the first magnetic part.

Alternatively, the second magnetic part may be disposed to be spaced apart from the first magnetic part by a predetermined distance. For example, the separation distance between the first magnetic part and the second magnetic part is 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. can

In addition, referring back to FIG. 3C , the first magnetic part 300 may have a groove on the surface facing the shield part 400 , and the second magnetic part 500 may be inserted into the groove to be disposed. have.

In this case, since the first magnetic part may serve as a housing of the second magnetic part, a separate adhesive or structure for fixing the second magnetic part may not be required. In particular, since the first magnetic part can be molded into a three-dimensional structure through a mold using a polymer-type magnetic part using magnetic powder and a binder resin, a groove for inserting the second magnetic part can be easily formed.

In this case, at least a portion of the first magnetic part and the second magnetic part may contact the shield part. Accordingly, heat generated in the first magnetic part and/or the second magnetic part may be effectively discharged through the shield part.

The depth of the groove formed in the first magnetic part may be the same as or different from the thickness (height) of the second magnetic part. When the depth of the groove and the thickness of the second magnetic part are the same, the first magnetic part and the second magnetic part may contact the shield part at the same time. Alternatively, when the depth of the groove is smaller than the thickness of the second magnetic part, only the second magnetic part may contact the shield part. Conversely, when the depth of the groove is greater than the thickness of the second magnetic part, only the first magnetic part may contact the shield part.

Also, referring to FIGS. 3A , 3D and 3E , the second magnetic part 500 may be disposed to be spaced apart from the shield part 400 by a predetermined distance. In addition, a spacer part 700 may be further included between the second magnetic part 500 and the shield part 400 . The spacer part 700 may be an empty space. In addition, the spacer part 700 may further include a spacer insertion part adopting a material and structure of a housing commonly used in a wireless charging device, at least in part.

coil part

A wireless charging device according to an embodiment of the present invention includes a coil unit through which an alternating current flows to generate a magnetic field.

The coil unit may include a conductive wire.

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

In addition, the conductive wire may have an insulating sheath. For example, the insulating shell may include an insulating polymer resin. Specifically, the insulating shell may include a polyvinyl chloride (PVC) resin, a polyethylene (PE) resin, a Teflon resin, a silicone resin, a polyurethane resin, and the like.

The diameter of the conductive wire may be, for example, in the range of 1 mm to 10 mm, in the range of 1 mm to 5 mm, or in the range of 1 mm to 3 mm.

The conductive wire may be wound in the form of a flat coil. Specifically, the planar coil may include a planar spiral coil. In addition, the planar shape of the coil may be an elliptical shape, a polygonal shape, or a polygonal shape with rounded corners, but is not particularly limited.

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

In addition, the inner diameter of the planar coil may be 0.5 cm to 30 cm, 1 cm to 20 cm, or 2 cm to 15 cm.

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

In addition, the distance between the conductive wires in the planar coil shape may be 0.1 cm to 1 cm, 0.1 cm to 0.5 cm, or 0.5 cm to 1 cm.

When it is within the preferred planar coil dimension and specification range as described above, it may be suitable for a field requiring large-capacity power transmission, such as an electric vehicle.

The coil unit may be disposed to be spaced apart from the magnetic unit by a predetermined interval. For example, the distance between the coil unit and the magnetic unit may be 0.2 mm or more, 0.5 mm or more, 0.2 mm to 3 mm, or 0.5 mm to 1.5 mm.

When within the preferred plane coil unit dimensions and standard ranges as described above, it may be suitable for a field requiring large-capacity power transmission, such as an electric vehicle.

shield part

The wireless charging device 10 according to the embodiment may further include a shield unit 400 serving to increase wireless charging efficiency through electromagnetic wave shielding.

The shield part is disposed on one surface of the coil part.

The shield part includes a metal plate, and the material thereof may be aluminum, and other metal or alloy materials having electromagnetic wave shielding ability may be used.

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

In addition, the area of the shield part may be 200 cm ² or more, 400 cm ² or more, or 600 cm ² or more.

housing

The wireless charging device 10 according to the embodiment may further include a housing 600 accommodating the coil unit 200 , the first magnetic unit 300 , and the second magnetic unit 500 .

In addition, the housing 600 is configured such that components such as the coil unit 200, the shield unit 400, the first magnetic unit 300 and the second magnetic unit 500 are properly arranged and assembled. do. The shape (structure) of the housing may be arbitrarily set according to the components included therein or according to the environment. The material and structure of the housing may adopt a material and structure of a typical housing used in a wireless charging device.

support

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

On the other hand, the wireless charging device of the present invention can efficiently reduce heat generated when the coil unit receives wireless power from the outside when performing high-power wireless charging of 3 kW to 22 kW, 4 kW to 20 kW, or 5 kW to 18 kW, and charging Since efficiency can be improved, it can be usefully used for high-power wireless charging.

In particular, the wireless charging device may further improve charging efficiency and heat reduction characteristics by applying a three-dimensional structure to the magnetic part.

The charging efficiency of the wireless charging device according to an embodiment of the present invention may be 85% or more, 88% or more, 89% or more, 90% or more, or 91% or more.

Accordingly, the wireless charging device may be usefully used in an electric vehicle requiring large-capacity power transmission between a transmitter and a receiver.

[transportation]

6 is a moving means to which a wireless charging device is applied, specifically, an electric vehicle, and may be wirelessly charged in a parking area equipped with a wireless charging system for an electric vehicle by providing a wireless charging device at the lower part.

Referring to FIG. 6 , the electric vehicle 1 according to an embodiment includes the wireless charging device according to the embodiment as a receiver 720 .

The wireless charging device may serve as a receiver of wireless charging of the electric vehicle 1 and may receive power from a wireless charging transmitter 730 .

As such, the moving means includes a wireless charging device, and the wireless charging device includes a coil unit; and a magnetic part disposed on the coil part, wherein the magnetic part comprises: a first magnetic part disposed on the coil part; and a second magnetic part disposed adjacent to the first magnetic part, wherein a second inductance in a state in which only the second magnetic part remains and a first inductance in a state in which only the first magnetic part remains are different from each other.

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

The moving means may further include a battery receiving power from the wireless charging device. The wireless charging device may receive power wirelessly and transmit it to the battery, and the battery may supply power to a driving system of the electric vehicle. The battery may be charged by power transmitted from the wireless charging device or other additional wired charging devices.

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

Example

Example 1: Preparation of a wireless charging device

Step 1: Preparation of the first magnetic part (PMB magnetic part) (three-dimensional structure)

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

As shown in FIG. 5, the magnetic powder slurry was injected into a mold 703 by an injection molding machine 702 and molded to have the thickness shown in Table 1, and dried at a temperature of about 140° C. to have a three-dimensional structure. A first magnetic part was obtained.

Step 2: Fabrication of a hybrid magnetic part

A hybrid type in which a ferritic magnetic material (PC-95 ferrite magnetic sheet manufactured by TDK, a second magnetic part) is disposed on one surface of the outermost part corresponding to the coil part of the first magnetic part manufactured in step 1, and then thermocompressed and fixed got a magnet

Step 3: Fabrication of the wireless charging device

A wireless charging device including a coil part including a conductive wire, the hybrid magnetic part and a shield part was obtained by using the hybrid magnetic part of step 2. At this time, the ferritic magnetic material (second magnetic part) was disposed to face the shield part. The wireless charging device may have a structure similar to that of FIG. 3B .

Example 2

As shown in Table 1, a nanocrystalline magnetic material (manufactured by Hitachi) was disposed as the second magnetic part, and a spacer insertion part (thickness 3 mm) was disposed between the second magnetic part and the shield part. produced a wireless charging device in the same manner as in Example 1. The wireless charging device has a structure similar to that of FIG. 3E, and further includes the spacer insert.

Example 3

Step 1: Preparation of the first magnetic part (PMB magnetic part) (planar structure)

In step 1 of Example 1, the magnetic powder slurry was coated on a carrier film by a comma coater, and dried at a temperature of about 110° C. to form a dry magnetic composite. The dried magnetic composite was compression-hardened by a hot press process at a temperature of about 170° C. and a pressure of about 9 Mpa for about 60 minutes to obtain a sheet-type magnetic composite. The magnetic powder content of the magnetic composite thus prepared was about 90%, and the thickness of one sheet was about 100 μm. For the sheet, 40 to 50 sheets were stacked to obtain a first magnetic part having a thickness of about 4 mm.

Step 2 and Step 3

After arranging a ferritic magnetic material having a thickness of 1 mm (PC-95 ferrite magnetic sheet manufactured by TDK, a second magnetic part) on the first magnetic part prepared in step 1, thermocompression bonding to fix the hybrid type magnetic part was obtained, and this A wireless charging device was obtained in the same manner as in Example 1. The wireless charging device may have a structure similar to that of FIG. 3A .

Example 4

Example except that the first magnetic part obtained in step 1 of Example 3 was used as the first magnetic part and the thickness of the nanocrystalline magnetic material (manufactured by Hitachi Corporation) was adjusted to 1 mm as the second magnetic part A wireless charging device was obtained in the same way as in 2. The wireless charging device may have a structure similar to that of FIG. 3D.

Comparative Example 1

A wireless charging device was obtained in the same manner as in Example 3, except that only the first magnetic part (thickness 5 mm) obtained in step 1 of Example 3 was included.

Comparative Example 2

A wireless charging device was manufactured in the same manner as in Example 3, except that the first magnetic part obtained in step 1 of Example 3 was not used, and only the second magnetic part (thickness 5 mm), which was a ferritic magnetic material, was included. got it

test example

(One) Evaluation of the physical properties of the hybrid magnetic part

The characteristics of the hybrid magnetic part of Examples 1 to 4 and the polymer-type magnetic block (PMB) magnetic material of Comparative Example 1 and the ferritic magnetic material of Comparative Example 2 were compared in the following manner.

inductance

For inductance, LCR Meter (IM3533, HIOKI) was used. The results are shown in Table 1 below.

La measured the second inductance in a state in which only the second magnetic part remained after replacing the first magnetic part with the spacer part in the hybrid type magnetic part, and Lc was the first first after replacing the second magnetic part with the spacer part in the hybrid type magnetic part. The first inductance in a state where only the magnetic part remained was measured.

iron loss

- Basic measurement iron loss

Referring to FIG. 4, the first magnetic part and the second magnetic part having an outer diameter (Ot) of 50 mm, an inner diameter (It) of 30 mm, and a thickness (T) of 4 mm are respectively 100 kHz and 100 mT B-H meter (B-H Analyzer) was measured by

Specifically, dimensions and weights of the wireless charging devices of Examples and Comparative Examples were measured, and relative densities were calculated. We also measured the strength of the wireless charging device. And the basic measurement iron loss was measured at DC magnetization and magnetic flux density of 0.1 T and frequency of 100 kHz using DC and AC B-H measuring instruments.

- Composite iron loss (Ci)

Composite iron loss expressed by Equation 1 below was calculated using the above-described inductance and basic measured iron loss.

[Equation 1]

Ci = 0.51 × Lt × (a/La + c/Lc)

In Equation 1 above,

a is the iron loss per unit of measurement of the second magnetic part,

c is the iron loss per unit of measurement of the first magnetic part,

Lt is the inductance measured in a state in which the first magnetic part and the second magnetic part are mounted,

La is the second inductance,

Lc is the first inductance.

(2) Charging Efficiency Measurement

Charging efficiency was measured by SAE J2954 WPT2 Z2 Class standard TEST method. Specifically, SAE J2954 WPT2 Z2 Class standard TEST standard coil part and frame are applied, and 5T (mm) thick magnetic material and spacer, or 10T thick magnetic material and aluminum plate are stacked on the outer shell to receive pad (35 cm X 35 cm) and A transmission pad (75 cm X 60 cm) was manufactured, and charging efficiency was evaluated for 10 minutes under the same conditions with an output power of 6.6 kW at an 85 kHz frequency.

(3) Permeability measurement

Permeability was measured at 85 kHz frequency using impedance analysis equipment (Agilent's 4294A).

Since the size and thickness of each component shown in FIGS. 3A to 3E are exaggerated for explanation, refer to Table 1 below for the specific thickness of each magnetic part applied in the present embodiment.

As shown in Table 1, all of the wireless charging devices of Examples 1 to 4 are wireless charging devices including a hybrid magnetic part including a first magnetic part and a second magnetic part, and the second inductance and the first inductance are different from each other, and the composite iron loss (Ci) represented by Equation 1 was 1200 W/m 3 or less, and thus it was confirmed that the charging efficiency was improved.

In particular, as in Example 1, when a hybrid magnetic part having a thickness of 10 mm was used, the thickness of the magnetic part was increased to form a magnetic field of the same size, so the measurement of the first magnetic part (PMB) measured at 100 kHz It was confirmed that the iron loss per unit decreased to 1100 W/m3, and accordingly, the composite iron loss (Ci) was significantly reduced to 617.9 W/m3.

In addition, as in Examples 2 to 4, when a hybrid magnetic part having a thickness of 5 mm was used, it was confirmed that the composite iron loss (Ci) was 1108 W/m 3 to 1188 W/m 3 .

On the other hand, the wireless charging device of Comparative Example 1 was a wireless charging device to which only the first magnetic part (PMB) was applied as a magnetic part, and the iron loss was 2000 W/m3, which was significantly higher than that of the wireless charging devices of Examples 1-4. , which led to a decrease in charging efficiency.

On the other hand, in Comparative Example 2, a wireless charging device in which only a second magnetic part (ferritic) is applied as a magnetic part, the charging efficiency is similar to that of Example 1, but the weight is increased, and in this case, there is a problem in the process as well as the cost It is not preferable in terms of effectiveness.

Therefore, it was confirmed that when the wireless charging device of Examples 1 to 4 was used, charging efficiency and heat reduction characteristics could be improved in an efficient way.

1: means of transportation (electric vehicle)
10, 10a, 10b, 10c, 10d, 10e: wireless charging device
100: support part 200: coil part
300: first magnetic part 310: outer part
320: center 400: shield part
500: second magnetic part 600: housing
700: spacer part
701: raw material composition 702: injection molding machine
703 : mold
720: receiver 730: transmitter
Id: inner diameter of magnetic part
Od: outer diameter of magnetic part
T: thickness of magnetic part
A-A': incision line
B-B': incision line

Claims (13)

coil unit; and
and a magnetic part disposed on the coil part;
The magnetic part includes a first magnetic part and a second magnetic part,
The magnetic part has a composite iron loss (Ci) of 1200 W/m 3 or less represented by Equation 1 below, a wireless charging device:
[Equation 1]
Ci = 0.51 Х Lt Х (a/La + c/Lc)
In Equation 1 above,
a is the iron loss per unit of measurement of the second magnetic part,
c is the iron loss per unit of measurement of the first magnetic part,
Lt is the inductance measured in a state in which the first magnetic part and the second magnetic part are mounted,
La is the second inductance measured in a state where only the second magnetic part remains,
Lc is the first inductance measured when only the first magnetic part remains.
The method of claim 1,
In Equation 1, La and Lc are different from each other, a wireless charging device.
The method of claim 1,
The second magnetic part is disposed on the first magnetic part, a wireless charging device.
The method of claim 1,
The first magnetic part includes a magnetic powder and a binder,
The second magnetic part is at least one selected from the group consisting of a nanocrystalline magnetic material and a ferritic magnetic material, a wireless charging device.
3. The method of claim 2,
The second magnetic part comprises a nanocrystalline magnetic material,
The composite iron loss (Ci) is more than 700 W / m 3 to 1200 W / m 3 or less, a wireless charging device.
3. The method of claim 2,
The second magnetic part includes a ferritic magnetic material,
The composite iron loss (Ci) is 300 W / m 3 or more and less than 1120 W / m 3 , a wireless charging device.
3. The method of claim 2,
wherein a is less than or equal to 500 W/m
Wherein c is 500 W / m 3 or more,
The Lt is 25 to 60 μH,
Wherein La is 35 to 60 μH,
The Lc is 35 to 55 μH, the wireless charging device.
3. The method of claim 2,
The a / La is 1 W / ㎥ to 8 W / ㎥,
The c/Lc is 20 W/m 3 to 100 W/m 3 , a wireless charging device.
3. The method of claim 2,
The first magnetic portion has a thickness of 2 mm to 12 mm and a volume of 100 cm 3 to 1500 cm 3 ,
The second magnetic portion has a thickness of 0.04 mm to 5 mm and a volume of 1 cm 3 to 900 cm 3 , a wireless charging device.
10. The method of claim 9,
The first magnetic part and the second magnetic part have a thickness ratio of 1: 0.01 to 0.6 and a volume ratio of 1: 0.01 to 0.6, a wireless charging device.
3. The method of claim 2,
The first magnetic part has a magnetic permeability of 5 to 500 and an investment loss of 0 to 50 at 85 kHz,
The second magnetic part has a magnetic permeability of 1,000 to 20,000 and an investment loss of 0 to 500 at 85 kHz, a wireless charging device.
including a wireless charging device;
The wireless charging device
coil unit; and
and a magnetic part disposed on the coil part;
The magnetic part includes a first magnetic part and a second magnetic part,
The magnetic unit has a composite iron loss (Ci) of 1200 W/m 3 or less, expressed by the following Equation 1, a moving means:
[Equation 1]
Ci = 0.51 Х Lt Х (a/La + c/Lc)
In Equation 1 above,
a is the iron loss per unit of measurement of the second magnetic part,
c is the iron loss per unit of measurement of the first magnetic part,
Lt is the inductance measured in a state in which the first magnetic part and the second magnetic part are mounted,
La is the second inductance measured in a state where only the second magnetic part remains,
Lc is the first inductance measured when only the first magnetic part remains.
coil unit; and
and a magnetic part disposed on the coil part;
The magnetic part includes a first magnetic part and a second magnetic part,
The first inductance measured in the state where only the first magnetic part remains is 35 to 55 μH,
A second inductance measured in a state where only the second magnetic part remains is 35 to 60 μH, a wireless charging device.

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