Wireless charging coil winding

Abstract

The utility model discloses a wireless charging coil winding which comprises two or more layers of wireless charging coils, the two or more layers of wireless charging coils are stacked in the vertical direction, the wireless charging coils are composed of multiple turns of coils formed by winding wires from inside to outside in the horizontal direction, the width of the multiple turns of coils is gradually increased from inside to outside, and the width of the multiple turns of coils is gradually increased from inside to outside. The wire comprises a plurality of sub-wires wrapped by insulating layers, the plurality of sub-wires are wound in parallel, and the width of the same sub-wire is gradually increased from inside to outside. A single-turn coil is designed to be formed by winding a plurality of sub-conductors in parallel, the width of the same sub-conductor is gradually increased from inside to outside, and the width of a plurality of turns of coils is gradually increased from inside to outside, so that the problems of strong magnetic field of an inner ring, large eddy current, non-uniform current density caused by a skin effect and a proximity effect and the like are solved, and the resistance and the loss are effectively reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of wireless charging, in particular to a wireless charging coil winding. Background Art

[0002] Traditional wireless charging coils are usually made of a single-strand wire wound with multiple turns of coils, and the width of each turn of the coil is the same. This design has the problems of high resistance and high eddy current loss. The Chinese invention patent with publication number CN 109494058 A discloses a wireless charging coil. The wireless charging coil is composed of multiple turns of wire wound from the inside to the outside in a circumferential direction; the line width of the multiple turns of wire increases uniformly from the inside to the outside; the starting end of the innermost turn of wire is led out through the starting lead; the starting end of the innermost turn of wire and the terminal end of the outermost turn of wire are both connected to the rectifier circuit board of the device to be charged; the wireless charging coil is used to sense the electromagnetic signal emitted by the transmitter, generate alternating current, and transmit the alternating current to the rectifier circuit board; the rectifier circuit board is used to convert the alternating current into direct current to realize charging of the device to be charged. This solution can improve the charging efficiency. However, this solution is still wound with a single strand of wire, and the coil resistance is relatively large. Utility Model Content

[0003] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a wireless charging coil winding with low resistance.

[0004] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0005] A wireless charging coil winding comprises two or more layers of wireless charging coils, wherein the two or more layers of wireless charging coils are stacked in a vertical direction, wherein the wireless charging coils are composed of a multi-turn coil formed by winding a wire from the inside to the outside in a horizontal direction, wherein the line width of the multi-turn coil gradually increases from the inside to the outside, wherein the wire comprises a plurality of sub-wires wrapped with an insulating layer, wherein the plurality of sub-wires are wound in parallel, and the line width of the same sub-wire gradually increases from the inside to the outside.

[0006] Optionally, for a single-turn coil, the line widths of the multiple sub-conductors are the same.

[0007] Optionally, for a single-turn coil, the widths of the multiple sub-conductors gradually decrease from the inside to the outside.

[0008] Optionally, there is a gap between two adjacent sub-conductors.

[0009] Optionally, multiple sub-conductors are combined at the end of the innermost circle to form an inner port, and multiple sub-conductors are combined at the end of the outermost circle to form an outer port.

[0010] Optionally, the inner ports of the wireless charging coils are connected to each other, and the outer ports of the wireless charging coils are connected to each other.

[0011] The beneficial effect of the utility model is that a single-turn coil is designed to be wound in parallel with multiple sub-conductors, and the line width of the same sub-conductor gradually increases from the inside to the outside, and the line width of the multi-turn coil gradually increases from the inside to the outside, which solves the problems of strong magnetic field in the inner circle, large eddy current, and uneven current density caused by skin effect and proximity effect, while effectively reducing resistance and loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The figure shows a partial cross-sectional schematic diagram of the wireless charging coil in the vertical direction of an embodiment of the utility model;

[0013] Figure 2 The figure shows a partial cross-sectional schematic diagram of the wireless charging coil in the vertical direction of the first embodiment of the utility model;

[0014] Figure 3 Shown is a graph showing the change of the inductance Ls of the wireless charging coil winding of the first embodiment of the present invention and different comparison ratios;

[0015] Figure 4 The figure shows the change diagram of the DC resistance Rdc of the wireless charging coil winding of the first embodiment of the present utility model and different comparison ratios;

[0016] Figure 5 Shown is a graph showing the change in AC resistance Rs of the wireless charging coil winding of the first embodiment of the present invention and different comparison ratios.

[0017] Figure 6 The figure shows a partial cross-sectional schematic diagram of the wireless charging coil in the vertical direction of the second embodiment of the utility model;

[0018] Figure 7 Shown is a top view schematic diagram of a wireless charging coil according to a second embodiment of the present utility model.

[0019] Description of labels:

[0020] 1. Coil; 2. Wire; 21. Sub-wire. DETAILED DESCRIPTION

[0021] In order to more clearly understand the technical content, achieved purposes and effects of the utility model, the utility model is described in detail below in combination with specific implementation methods and in conjunction with the accompanying drawings. It should be noted that the implementation methods of the utility model and the features in the implementation methods can be combined with each other without conflict. In the following description, many specific details are set forth in order to fully understand the utility model. The implementation methods described are only part of the implementation methods of the utility model, not all of the implementation methods. Based on the implementation methods in the utility model, all other implementation methods obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0022] Please refer to Figure 1 , 2 , 6, and 7, the technical solution provided by the utility model is:

[0023] A wireless charging coil winding comprises two or more layers of wireless charging coils, wherein the two or more layers of wireless charging coils are stacked in a vertical direction, wherein the wireless charging coil is composed of a multi-turn coil 1 formed by winding a wire 2 from the inside to the outside in a horizontal direction, wherein the line width of the multi-turn coil 1 gradually increases from the inside to the outside, wherein the wire 2 comprises a plurality of sub-wires 21 wrapped with an insulating layer, wherein the plurality of sub-wires 21 are wound in parallel, and the line width of the same sub-wire 21 gradually increases from the inside to the outside.

[0024] From the above description, it can be seen that the wireless charging coil winding of the utility model has a multi-turn coil with gradually increasing line width from the inside to the outside, which effectively solves the problems of strong magnetic field in the inner circle, large eddy current, and uneven current density caused by skin effect and proximity effect. The single-turn coil is designed to be wound with multiple sub-conductors in parallel, and the line width of the same sub-conductor gradually increases from the inside to the outside, which can effectively reduce inductance, resistance and loss.

[0025] Optionally, for the single-turn coil 1 , the line widths of the plurality of sub-conductors 21 are the same.

[0026] Optionally, for the single-turn coil 1 , the line widths of the plurality of sub-conductors 21 gradually decrease from the inside to the outside.

[0027] It can be seen from the above description that in a single-turn coil, the line width of the multiple sub-conductors gradually decreases from the inside to the outside, thereby further reducing the resistance.

[0028] Optionally, there is a gap between two adjacent sub-conductors 21 .

[0029] From the above description, it can be seen that in a specific implementation, for a single-turn coil, the gaps between two adjacent sub-conductors can be set to be the same, and the gaps between two adjacent turns of the coil can be set to be the same. As the coil moves from the inside to the outside, the gaps between adjacent sub-conductors in each turn of the coil can be set to be the same, or the gaps between adjacent sub-conductors can be set to gradually increase from the inner turn to the outer turn.

[0030] Optionally, multiple sub-conductors 21 are combined at the ends of the innermost circle to form an inner port, and multiple sub-conductors 21 are combined at the ends of the outermost circle to form an outer port.

[0031] Optionally, the inner ports of the wireless charging coils are connected to each other, and the outer ports of the wireless charging coils are connected to each other.

[0032] Please refer to Figure 1-5 , Embodiment 1 of the present utility model is:

[0033] A wireless charging coil winding, comprising two or more layers of wireless charging coils, the two or more layers of wireless charging coils are stacked in a vertical direction, the wireless charging coils are composed of a multi-turn coil 1 formed by winding a wire 2 from inside to outside in a horizontal direction, and the line width of the multi-turn coil 1 gradually increases from inside to outside. Figure 1 As shown, the coil is shown from left to right from inside to outside.

[0034] The conductor 2 includes a plurality of sub-conductors 21 wrapped with an insulating layer, and the plurality of sub-conductors 21 are wound in parallel, with a gap between two adjacent sub-conductors 21. The line width of the same sub-conductor 21 increases gradually from the inside to the outside. For a single-turn coil 1, the line width of the plurality of sub-conductors 21 is the same. Figure 2 As shown, from left to right in the figure, the sub-conductors are from inside to outside. Multiple sub-conductors 21 are combined at the end of the innermost circle to form an inner port, and multiple sub-conductors 21 are combined at the end of the outermost circle to form an outer port. The inner ports of each wireless charging coil are connected to each other, and the outer ports of each wireless charging coil are connected to each other.

[0035] The following example uses a coil with 11 turns and 4 sub-conductors. The inner and outer diameters of the coil are fixed. In a single-turn coil, the line width of the four sub-conductors is kept consistent. As the coil moves from the inside to the outside, the line width of the wire is gradually increased. That is, from the innermost turn to the outermost turn, the line width of the single-turn coil changes from thin to thick. Table 1 below shows the effect of 14 different line width design schemes on performance. Loop1-Loop11 in the table represent the line width of the wire of the 1st turn coil from the inside to the outside, corresponding to the line width of the 11th turn coil. Figure 1 The wire width of the coils arranged from left to right in the figure is in mm; the inner diameter is the inner diameter of the wireless charging coil in mm, the outer diameter is the outer diameter of the wireless charging coil in mm, Ls is the inductance of the wireless charging coil winding in μH, Rdc is the DC resistance of the wireless charging coil winding in mohm, and Rs is the AC resistance of the wireless charging coil winding in mohm. Among them, Schemes 1-7 are wireless charging coil windings using this embodiment. Schemes 8-14 are comparative examples.

[0036]

[0037]

[0038] Table 1

[0039] like Figure 3 The figure shows the variation of the inductance Ls of the wireless charging coil winding obtained from the above 14 schemes, wherein the abscissa is the scheme number and the ordinate is the inductance Ls. Figure 4 The figure shows the variation diagram of the DC resistance Rdc of the wireless charging coil winding obtained from the above 14 schemes, wherein the horizontal axis is the scheme number and the vertical axis is the DC resistance Rdc. Figure 5 The figure shows the change diagram of the AC resistance Rs of the wireless charging coil winding obtained from the above 14 schemes, wherein the horizontal axis is the scheme number and the vertical axis is the DC resistance Rs.

[0040] From Table 1 and Figure 3-5 It can be seen that as the coil moves from the innermost to the outermost, the design in which the wire width gradually increases (i.e., the coil width gradually increases) is better than the design in which the wire width remains unchanged (i.e., the coil width remains unchanged) or the wire width gradually decreases (i.e., the coil width gradually decreases). In addition, as the inner circle wire becomes thinner and the outer circle wire becomes wider, the inductance Ls and the AC Rs resistance are significantly reduced.

[0041] Please refer to Figure 1 , 6 , 7, the second embodiment of the utility model is:

[0042] A wireless charging coil winding, which is different from the above-mentioned embodiment 1 in that, for a single-turn coil 1, the line width of the plurality of sub-conductors 21 gradually decreases from the inside to the outside. Figure 6 FIG. 1 is a partial cross-sectional schematic diagram of the wireless charging coil of this embodiment in the vertical direction, in which the sub-conductors are shown from the inside to the outside from left to right. Figure 7 The figure shows a schematic top view of the wireless charging coil of this embodiment, where the line width of the single-turn coil changes from thin to thick from the innermost turn coil to the outermost turn coil. In the single-turn coil, the line width of the four sub-conductors decreases from the inside to the outside.

[0043] In summary, when designing a wireless charging coil, it is necessary to consider the problems of strong magnetic field in the inner circle, large eddy current, and uneven current density caused by skin effect and proximity effect. Therefore, the overall design of the coil of the utility model is from the inner circle to the outer circle, and the coil wire diameter is from thin to thick. At the same time, in order to reduce the resistance and loss of the coil, the single-turn coil is designed to be wound with multiple strands of sub-conductors, and the line width of the same sub-conductor gradually increases from the inside to the outside to reduce resistance and loss. For the design of the inner sub-conductor of the single-turn coil, the sub-conductor changes from thick to thin from the inside to the outside to further reduce resistance. Taking all factors into consideration, the coil line width gradually increases from the inside to the outside, and the line width of the sub-conductor in the single-turn coil gradually decreases from the inside to the outside.

[0044] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Therefore, any modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A wireless charging coil winding, comprising two or more layers of wireless charging coils, wherein the two or more layers of wireless charging coils are stacked in a vertical direction, characterized in that: The wireless charging coil is composed of a multi-turn coil formed by winding a wire from the inside to the outside in a horizontal direction, and the line width of the multi-turn coil gradually increases from the inside to the outside. The wire includes multiple sub-wires wrapped with an insulating layer, and the multiple sub-wires are wound in parallel. The line width of the same sub-wire gradually increases from the inside to the outside.

2. The wireless charging coil winding according to claim 1, characterized in that: For a single-turn coil, the line widths of multiple sub-conductors are the same.

3. The wireless charging coil winding according to claim 1, characterized in that: For a single-turn coil, the width of multiple sub-conductors gradually decreases from the inside to the outside.

4. The wireless charging coil winding according to claim 1, characterized in that: There is a gap between two adjacent sub-conductors.

5. The wireless charging coil winding according to claim 1, characterized in that: A plurality of sub-conductors are combined at the end of the innermost circle to form an inner port, and a plurality of sub-conductors are combined at the end of the outermost circle to form an outer port.

6. The wireless charging coil winding according to claim 1, characterized in that: The inner ports of the wireless charging coils are connected to each other, and the outer ports of the wireless charging coils are connected to each other.

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