KR20220081760A - Wireless charging device for electronic devices - Google Patents

Abstract

The present invention proposes a wireless charging device for electronic devices that can be charged uniformly and with high efficiency in all areas regardless of the location and direction in which the electronic device to be charged is placed. A wireless charging device, a ferromagnetic material of a predetermined size (ferromagnetic or ferrimagnetic substance); and a plurality of coil bodies installed on the ferromagnetic body. In addition, the coil bodies are disposed while inclined from the ends of the left and right upper surfaces of the ferromagnetic material toward the center lower surface, or disposed while being inclined parallel to each other in the same direction from the upper surface to the lower surface of the ferromagnetic material.

Description

Wireless charging device for electronic devices

The present invention relates to a wireless charging device, and more particularly, to a wireless charging device for an electronic device that can be charged uniformly and with high efficiency in all areas regardless of the location and direction in which the electronic device to be charged is placed.

A method of charging an electronic device such as a smart phone can be divided into a contact type charging method and a non-contact type charging method. The contact-type charging method is a method in which charging is performed by directly contacting an electrode connected to a battery of an electronic device and an electrode of a power feeding means, and is generally used in various fields due to its simple structure. However, there is the inconvenience of having to physically connect the electrode of the electronic device and the electrode of the power feeding means, such as a connector connection.

In order to solve the inconvenience of the contact-type charging method, a non-contact charging method has been proposed. The non-contact charging method, that is, the wireless charging method, is a method of charging using the principle of electromagnetic induction. A wireless charger is equipped with a transmitting coil and an electronic device that is a charging target is equipped with a receiving coil, and the magnetic induction method between the transmitting coil and the receiving coil is It is a method of charging a battery provided in an electronic device by converting the current generated by the device into energy.

The above-described conventional wireless charging method can be roughly divided into two types. One is the 'vertical magnetic flux approach' method (vertical charging method), and the other is the 'horizontal magnetic flux approach' method (horizontal charging method).

In the vertical charging method, as shown in FIG. 1A , a charging device (transmitter) and an electronic device (receiver) are vertically disposed so that a magnetic field is formed in a vertical direction. This is the method currently adopted by most wireless charging devices. The vertical charging method can provide sufficient charging efficiency at a predetermined location such as a charging area inside the transmission coil, but on the other hand, there is a problem in that the magnetic field exposure is large and power pulsation occurs in the vertical direction. In particular, when expanding to a wide range for charging, the charging device must have a configuration in which a plurality of coils are arranged in a horizontal direction as shown in FIG. 1B, making optimization difficult and heat generation problems occur.

In the horizontal charging method, as shown in FIG. 2A , the charging device and the electronic device are horizontally arranged so that a magnetic field is formed in a horizontal direction. The charging range is wide because the charging area is between the transmitting coils. In addition, compared to the vertical charging method, the distance between the transmitting coils is sufficiently spaced apart, so that there is less interference between the coils, so optimization is easy, and there is an advantage in that heat is relatively small because many coils are not required for expansion. However, since the surface where the receiving coil of the electronic device meets the magnetic field must be wide, the charging efficiency is lower than that of the vertical charging method, so the effectiveness is not good.

As such, the charging method of the conventional wireless charging device has problems in that it is difficult to have uniform charging efficiency over a large area, and the charging efficiency is low. In addition, most of the conventional wireless charging methods have a problem in that the degree of freedom is limited as most of them have a structure in which only 1:1 charging is possible at a fixed location.

Accordingly, an object of the present invention is to provide a wireless charging device for electronic devices that can provide a uniform and sufficiently high charging efficiency in a wider range compared to the conventional wireless charging method.

Another object of the present invention is to provide a wireless charging device for electronic devices that allows the charging area to be freely expanded.

A wireless charging device for an electronic device according to an embodiment of the present invention, a ferromagnetic material (ferromagnetic or ferrimagnetic substance) of a predetermined size; and a plurality of coil bodies installed on the ferromagnetic body, wherein the coil body is a first coil body and a second coil body on which a coil is wound, and the first coil body and the second coil body are left and right upper surfaces of the ferromagnetic body. It is characterized in that it is disposed while being inclined toward the lower surface of the center at the end.

The centers of the first coil body and the second coil body facing each other are installed to be spaced apart from each other by a predetermined distance.

The ferromagnetic material is made of ferrite.

A wireless charging device for an electronic device according to another embodiment of the present invention, a ferromagnetic material (ferromagnetic or ferrimagnetic substance) of a predetermined size; and a plurality of coil bodies installed on the ferromagnetic body, wherein the plurality of coil bodies are disposed while being inclined parallel to each other in the same direction from an upper surface to a lower surface of the ferromagnetic body.

The ferromagnetic material is made of ferrite.

According to another embodiment of the present invention, in the wireless device for electronic devices, at least one ferromagnetic body in which the coil body is installed is further installed in a vertical or horizontal direction to expand a charging area.

According to the wireless charging device for electronic devices of the present invention configured as described above, a ferromagnetic material (ferrite plate) is adopted as a transmission medium instead of air, and a plurality of coil bodies with coils wound therein are used while facing each other and symmetrically inclined, or the same It was arranged to be inclined side by side in the direction.

As a result, the effective magnetic field size of the wireless charging device is improved to provide an effect of charging electronic devices with the same charging efficiency in all areas of the wireless charging device. That is, it is possible to charge the electronic device no matter where the electronic device is placed in the charging device.

In addition, in the present invention, since two or more transmitting coil bodies are arranged obliquely, interference between the transmitting coils can be minimized.

1 is a view showing a vertical charging method in which a conventional transmitter and a receiver are vertically arranged;
2 is a view illustrating a conventional horizontal charging method in which a transmitter and a receiver are horizontally disposed;
3 is a view showing a first charging method applied to the wireless charging device of the present invention;
4 is a view showing a second charging method applied to the wireless charging device of the present invention;
5 is an exemplary view comparing mutual inductance values when the transmission coil is installed in the prior art (that is, referring to FIGS. 1 and 2) and when the coil body is installed at an angle as in the first charging method of FIG. 3
6 is an exemplary view comparing mutual inductance values when the transmission coil is installed in the prior art (that is, referring to FIGS. 1 and 2) and when the coil body is installed at an angle like the second charging method of FIG.
7 is a graph comparing the transmission efficiency of the transmitter of the present invention and another transmitter;
8 is an exemplary view using a plurality of transmission coils to expand the charging area in the prior art;
9 is a simulation of the basic structure and mutual inductance change of the transmitter to which the coil structure of the first charging type shown in FIG. 3 is applied; FIG.
10 is a structure in which the ferrite plate, which is the basic structure of the present invention, extends in a vertical direction, and a simulation of changes in mutual inductance;
11 is a structure in which a ferrite plate, which is the basic structure of the present invention, is extended in the horizontal direction and a simulation of changes in mutual inductance;

It should be noted that the technical terms used in the present invention are only used to describe specific embodiments, and are not intended to limit the present invention. In addition, the technical terms used in the present invention should be interpreted as meanings generally understood by those of ordinary skill in the art to which the present invention belongs, unless otherwise defined in the present invention. It should not be construed in the meaning of a human being or in an excessively reduced meaning. In addition, when the technical term used in the present invention is an incorrect technical term that does not accurately express the spirit of the present invention, it should be understood by being replaced with a technical term that can be correctly understood by those skilled in the art. In addition, the general terms used in the present invention should be interpreted according to the definition in the dictionary or according to the context before and after, and should not be interpreted in an excessively reduced meaning.

Also, the singular expression used in the present invention includes the plural expression unless the context clearly dictates otherwise. In the present invention, terms such as “consisting of” or “comprising” should not be construed as necessarily including all of the various components or various steps described in the invention, some of which components or some steps are included. It should be construed that it may not, or may further include additional components or steps.

Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings, but the same or similar components are given the same reference numerals regardless of reference numerals, and redundant description thereof will be omitted.

In addition, in the description of the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, it should be noted that the accompanying drawings are only for easy understanding of the spirit of the present invention, and should not be construed as limiting the spirit of the present invention by the accompanying drawings.

3 is a view showing a first charging method applied to the wireless charging device of the present invention. As shown in FIG. 1 , the wireless charging device 100 to which the first charging method is applied is provided with a ferrite plate 110 having a substantially rectangular parallelepiped shape having a predetermined size (width×length×thickness). The ferrite plate 110 may be one having a predetermined thickness, or a plurality of thin ferrite plates may be stacked to form one. As such, in the present invention, a ferromagnetic or ferrimagnetic substance such as the ferrite plate 110 is adopted as a transmission medium instead of air.

The ferrite plate 110 has higher permeability than air. Looking at the equation (the following equation) based on the modeling of a general wireless power transmission circuit, it can be seen that when a medium with higher permeability than air is used, the charging range can be extended while increasing the efficiency. This high ferrite material is used.

The ferrite plate 110 is provided with a first coil body 120a and a second coil body 120b as a coil body for wireless transmission of charging power. The first coil body 120a and the second coil body 120b are formed in a rectangular shape corresponding to the shape of the ferrite plate 110 , and the inside is empty and only the upper/lower/left/right edges are wound with coils. The shapes and structures of the first coil body 120a and the second coil body 120b are the same.

As shown in FIG. 3 , the first coil body 120a and the second coil body 120b are installed to be inclined at a predetermined angle from the end of the upper surface of the ferrite plate 110 toward the lower surface of the center. In addition, the first coil body 120a and the second coil body 120b have one end facing each other in the center and spaced apart from each other by a predetermined distance. That is, when viewed in cross-section, the first coil body 120a and the second coil body 120b are placed in a substantially V-shape spaced apart from each other by a predetermined distance without the central portions contacting each other.

4 is a view showing a second charging method applied to the wireless charging device of the present invention. The wireless charging device 200 to which the second charging method of FIG. 4 is applied is provided with a ferrite plate 210 having a substantially rectangular parallelepiped shape having a predetermined size (width×length×thickness), and the ferrite plate 210 ), the first coil body 220a and the second coil body 220b are installed to be parallel to each other while being inclined. That is, when viewed in cross section, it is installed in an oblique shape. The first coil body 220a and the second coil body 220b have a coil wound therein, and have a rectangular shape with an empty interior. It can be said that there are only four side surfaces, and the upper and lower surfaces are unformed.

According to an embodiment of the present invention, the two coil bodies 120a, 120b, 220a, 220b in which the coil is wound on the ferrite plates 110 and 210 show a structure in which they are installed in an inclined manner while being uniformly spaced apart, but the present invention It will be natural that three or more coil bodies can be installed on the silver ferrite plate. It can be variously deformed in consideration of the size of the ferrite plate, the size of the coil body, and the charging area.

As described above, in the present invention, as shown in FIGS. 3 and 4 , the first coil body 120a and the second coil body 120b are spaced apart from the center of the ferrite plates 110 and 210 while being inclined at a predetermined angle. It is installed symmetrically to each other, or the first coil body 220a and the second coil body 220b are installed while being inclined in the same direction in parallel. In this way, when a plurality of coil bodies are installed to be inclined on one ferrite plate 110 , 210 , since magnetic fields formed in each coil body can cancel each other, there is an advantage in that efficiency is increased.

Meanwhile, when the coil is wound in an inclined manner as in FIGS. 3 and 4 , a mutual inductance value is also improved, and simulation results for this are shown in FIGS. 5 and 6 .

5 is an exemplary view comparing mutual inductance values when the transmission coil is installed in the prior art (that is, referring to FIGS. 1 and 2) and when the coil body is installed at an angle as in the first charging method of FIG. 3, According to the calculation results, it was confirmed that the average value of the conventional inductance value was 0.9 and the present invention was about 4.69, which was improved by about 5.5 times or more.

6 is an exemplary view comparing mutual inductance values when the transmission coil is installed in the prior art (that is, referring to FIGS. 1 and 2) and when the coil body is installed at an angle as in the second charging method of FIG. Similarly, according to the calculation results, it was confirmed that the average value of the conventional inductance value was 0.9, whereas the present invention was about 5.13, which was improved by about 5.7 times.

From this, it can be confirmed that the charging method efficiency of the present invention is improved compared to the prior art. Furthermore, it can be seen that the efficiency of the second charging method is better among the first charging method and the second charging method of the present invention.

Meanwhile, in the first charging method and the second charging method of the present invention, since the coil body is formed in a horizontal direction, it can be called an advanced horizontal approach. It has a structure in which a plurality of transmission coils are provided. Looking at the efficiency of a transmitter to which one general transmission coil, a plurality of non-slanted transmission coils, and a plurality of transmission coils wound obliquely as in the present invention are applied, the transmission unit of the present invention has higher efficiency than other transmission coils.

Indices indicating the efficiency performance of each transmitter according to the experimental results are shown in FIGS. 7A and 7B . This shows the transmission efficiency in the horizontal (x-axis) - vertical (y-axis) direction of the transmitter, and it can be seen that the efficiency appears uniformly over the entire area of the transmitter. In other words, it means that wireless charging can be performed efficiently even if the receiver is positioned regardless of the location of the transmitter.

According to the present invention, it is possible to freely expand the charging area by locating the transmitting units adjacent to each other. The key is to minimize interference between transmitters, which can be verified through experiments.

As described above, in the case of the charging method in which the conventional charging device (transmitter) and the electronic device (receiver) are vertically arranged, a plurality of coils are required if a wide charging range is desired. ) could have avoided the problem. However, in this case, heat generation is inevitable, and since the number of coils used is large, there is a problem in optimizing the spacing between the coils. The larger the charging range, the more difficult it is to optimize, so it was not possible to implement a charging device that can be freely arranged in a practically large area. For example, FIG. 8 is an exemplary diagram in which about 20 transmission coils are used in a charging device of a certain area, but it has the above-mentioned problems as it is, and thus the wireless power could not be effectively supplied.

On the other hand, the present invention provides effects that can be optimized because the number of coils is small, charging of a large area is possible, there is no heat problem, and there is no interference problem between the coils. This was verified through simulation.

9 is a basic structure of a transmitter to which the coil body structure of the first charging method shown in FIG. 3 is applied. As shown in FIG. 9A , when the size of the ferrite plate is 10 cm×10 cm and the widths of the first coil body and the second coil body are 25 mm, respectively, a simulation of a change in mutual inductance is the same as that of FIG. 9B .

In contrast, FIGS. 10 and 11 are cases in which the basic structure of FIG. 9 is expanded in a vertical direction (y-axis) and a horizontal direction (x-axis), respectively, and show simulations of changes in mutual inductance.

Even if the ferrite plate, which is the basic structure, is extended in the vertical direction as shown in FIG. 10A, coupling between the transmission coils does not appear significantly as shown in FIG. 10B, so the size of the mutual inductance does not significantly affect the uniformity. can be known It can be said that the scalability is better than the basic structure.

This is also the case in the case of extending in the horizontal direction. As a result of extending in the horizontal direction as shown in FIG. 11A, the mutual inductance increases and decreases as shown in FIG. 11B, but coupling between the transmission coils does not appear significantly. Therefore, it can be seen that the scalability is improved even when it is extended in the horizontal direction.

As described above, the present invention employs a ferromagnetic material (ferrite plate) instead of air as a transmission medium for a charging device for wireless charging, and uses a plurality of coil bodies with coils wound thereon while facing each other and symmetrically inclined or arranged side by side in the same direction. It can be seen that the same charging efficiency can be provided in all areas of the charging device by improving the effective magnetic field size by arranging it to be slanted.

Although the above has been described with reference to the embodiments, those skilled in the art can variously modify and change the present invention within the scope without departing from the spirit and scope of the present invention described in the claims below You will understand.

100, 200: wireless charging device
110, 210: ferrite plate
120a, 220a: first coil body
120b, 220b: second coil body

Claims (6)

a ferromagnetic substance of a predetermined size; and
It includes a plurality of coil bodies installed on the ferromagnetic body,
The coil body is a first coil body and a second coil body on which a coil is wound,
The wireless charging device for electronic devices, characterized in that the first coil body and the second coil body are disposed while inclined toward the center lower surface from the left and right upper surface ends of the ferromagnetic material. The method of claim 1,
A wireless charging device for electronic devices in which the center of the first coil body and the second coil body facing each other is installed to be spaced apart from each other by a predetermined distance. The method of claim 1,
The ferromagnetic material is a wireless charging device for electronic devices made of ferrite (ferrite). a ferromagnetic or ferrimagnetic substance of a predetermined size; and
It includes a plurality of coil bodies installed on the ferromagnetic body,
The plurality of coil bodies, the wireless charging device for electronic devices, characterized in that the ferromagnetic material is disposed while inclined parallel to each other in the same direction from the upper surface to the lower surface. 5. The method of claim 4,
The ferromagnetic material is a wireless charging device for electronic devices made of ferrite (ferrite). [Claim 5] The wireless charging device for electronic devices, characterized in that at least one of the ferromagnetic bodies in which the coil body of claim 1 or 4 is installed is further installed in a vertical or horizontal direction to expand a charging area.

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