JP2012151293A - Printed coil for air power transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printed coil for air power transmission, capable of improving resonance characteristics with a compact flat coil pattern by generating a coil on a substrate by a printing method using a conductive ink, capable of simplifying a coil configuration, and further to provide an air power transmission system using the printed coil for air power transmission.SOLUTION: The printed coil for air power transmission is formed by printing a conductive ink on one or both faces of a substrate in a plurality of strips of coil shape.

Description

  The present invention relates to a resonance coil used in aerial power transmission or wireless power feeding that transfers power without direct connection. Specifically, the present invention relates to an aerial power transmission printing coil in which a coil can be easily printed and formed with a conductive ink such as silver paste and a reduction in power transmission efficiency is suppressed.

  In aerial power transmission, power transfer is performed by the power receiving coil resonating with the magnetic flux generated by the power transmitting coil. The resonant coil has a wire length corresponding to the wavelength of the frequency used, and high resonance characteristics are required. Therefore, a thick copper wire is used and a large diameter is required.

  Therefore, there have been problems such as difficulty in manufacturing such as a process for forming an advanced winding shape and a coil holding structure, and a high price of copper wire.

  Moreover, although the application as an operation principle of aerial power transmission has been made (Patent Document 1, Patent Document 2), there is no description regarding a coil creation method.

  On the other hand, a small planar coil pattern can be easily created by printing with conductive ink such as silver paste, but the resistance component increases due to the high conductivity of the ink material, and the coil shape is disadvantageous in the plane. As a result, there is a problem that the resonance characteristics are extremely inferior.

  In addition, as a small planar coil pattern, there is an application using a copper foil pattern (Patent Document 3), but it cannot be created very easily because it is composed of a copper foil printed board or a different driving method.

Special table 2010-533472 gazette JP 2010-063245 A JP 2010-073976 A

  It is an object of the present invention to provide a printed coil for aerial power transmission that is created by printing conductive ink on a substrate, can improve resonance characteristics with a small planar coil pattern, and can further simplify the coil configuration. Is to provide. Furthermore, it is providing the air power transmission system using the said printed coil for air power transmission.

  That is, this invention relates to the printed coil for aerial power transmission formed by printing the conductive ink in the shape of a plurality of coils on one side or both sides of a substrate.

  The present invention also relates to the above-described printed coil for electric power transmission, wherein the conductive ink is a silver paste.

  In the present invention, the coil shape has a midpoint between the start end and the end, the capacity from the start end to the midpoint corresponds to the coil reactance and the use frequency, and the midpoint to the end corresponds to the use frequency. The present invention relates to the above-described printed coil for electric power transmission, which has a line length and is connected to an external connection terminal at a midpoint.

  The present invention also relates to the above-described aerial power transmission printed coil, which is formed by symmetrical printing on both surfaces of a substrate.

  The present invention also relates to an aerial power transmission system using the aerial power transmission printed coil.

  According to the present invention, it is possible to obtain an aerial transmission coil that is easy to produce and has sufficient resonance characteristics.

FIG. 1 shows an example (external dimension: 14 cm) of a printed coil pattern for aerial power transmission according to the present invention. FIG. 2 shows an example of using the aerial power transmission printed coil of the present invention. FIG. 3 shows the transmission characteristics of an aerial power transmission system using a printed coil for aerial power transmission according to the present invention. FIG. 4 is an example of the printed coil pattern for aerial power transmission according to the present invention shown in FIG. 5 in which capacitive components are incorporated in parallel. FIG. 5 shows an electrical circuit diagram 1 of a printed coil for air power transmission according to the present invention. FIG. 6 shows an electric circuit diagram 2 of the printed coil for aerial power transmission according to the present invention.

  The present invention will be specifically described.

  The present invention is a printed coil for aerial power transmission in which a conductive ink is printed in a plurality of coil shapes on one side or both sides of a substrate.

  Here, as the substrate, PET (polyethylene terephthalate), PEN (polypolyethylene naphthalate), or the like can be used. Of these, PEN is preferable.

  Examples of the conductive ink include silver paste, carbon paste, and nano metal wire paste. Of these, silver paste is preferable.

  Examples of the method for printing the conductive ink on the substrate include a screen, flexo, gravure, and ink jet. Of these, screen printing is preferable.

  Printing on the base material functions as an aerial power transmission printing coil on either one side or both sides, but double-sided printing is preferred because it can lower the resistance component and enhance resonance characteristics. In addition, when performing double-sided printing, it is preferable to perform symmetrical printing so that the coil shape overlaps with the substrate interposed therebetween.

  Front / back connection in double-sided printing is necessary at the coil start, end, and halfway point, but it can be realized at the same time by printing on the base material at the corresponding location, which is a major advantage of coil manufacturing by printing It is.

  Here, the coil start end corresponds to 1 in FIG. 1 and serves as a connection terminal for power transmission or power reception.

  The midway point of the coil corresponds to 4 in FIG. 1 and is a position on the coil for obtaining a capacity corresponding to the coil reactance and the operating frequency from the coil start end. Connection point.

  The coil end corresponds to 3 in FIG. 1, and the line length from the midway point of the coil to the coil end is a line length corresponding to the operating frequency.

  As the coil shape, a pattern as shown in FIG. 1 is printed on the front and back sides, and the starting end is short-circuited, so that the resistance component is expected to be halved and the resonance characteristics are improved.

  As an example of the coil shape, FIG. 4 shows a coil pattern in which a facing component is formed on the front and back and a capacitive component is formed.

  The capacity according to the coil reactance and the use frequency is the use frequency f, the reactance L, and the capacitance C is C represented by f = 1 / 2π√LC.

  The line length corresponding to the used frequency generally indicates half of the wavelength or 1 / integer.

  When an aerial power transmission system is constructed using the aerial power transmission printed coil of the present invention, high frequency power from a high frequency oscillation circuit is input to a resonance coil on the transmission side, and power is received on a magnetic flux line axis formed by magnetic flux. The other resonance coil is arranged.

  The transmission efficiency of aerial transmission was determined by measuring the input power on the power transmission side and the power generated in the load resistance on the power reception side. The measurement method is as follows: • Input a sine wave signal, measure the effective value of the input current and voltage to obtain the input power, and the receiving side calculates the ratio as the received power from the actual value of the voltage generated at the load resistance. is there.

  Hereinafter, the present invention will be described with reference to the following examples, but the present invention is not limited to the following examples.

Example 1
A coil pattern shown in FIG. 1 is formed on both sides of a PEN substrate (Q65FA manufactured by Teijin Co., Ltd.) having a size of 14 cm × 14 cm and a thickness of 125 μm by screen printing silver paste (RA FS049 manufactured by Toyo Ink Manufacturing Co., Ltd.). Then, two printed coils for air power transmission were created. The printing conditions were three times of overcoating, and the drying conditions were the first time, the second time at 120 ° C. for 10 minutes, and the third time at 150 ° C. for 30 minutes.

  The obtained two printed coils for aerial power transmission are installed coaxially and in parallel as coils on the power transmission side and power reception side (see FIG. 2), and the output of the high frequency oscillator is shown in FIG. The receiving coil was wired as shown in FIG.

  Using an oscilloscope (Tektronix TDS3032), the transmission efficiency was obtained from the effective value of the voltage / current for the power transmission side and the effective value of the voltage generated at the load resistance for the power reception side. FIG. 3 shows the measurement results obtained by changing the distance between the coils.

  According to FIG. 3, it can be seen that the aerial power transmission system using the printed coil for aerial transmission according to the present invention can obtain a high transmission efficiency, and a transmission efficiency as high as 70% is obtained especially at a distance of 8 cm. .

  From this result, it was confirmed that the printed coil for aerial transmission of the present invention was easy to produce and had sufficient resonance characteristics.

1. 1. External connection terminal that is the coil start end 2. External connection terminal from the middle of the coil 3. Coil termination Coil halfway point

Claims (5)

  A printed coil for aerial power transmission, in which a conductive ink is printed on one or both sides of a base material in the form of a plurality of coils.   The printed coil for aerial power transmission according to claim 1, wherein the conductive ink is a silver paste.   The coil shape has a halfway point between the start end and the end point, the capacity from the start point to the halfway point according to the coil reactance and the use frequency, and the wire length from the halfway point to the end point according to the use frequency, The printed coil for aerial power transmission according to claim 1, wherein a connection terminal to the outside is connected at a midpoint.   The printed coil for aerial power transmission according to claim 1, wherein the coil portions are symmetrically printed on both surfaces of the base material. An aerial power transmission system using the aerial power transmission printed coil according to claim 1.

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