Wireless charging coil winding

Abstract

The utility model discloses a wireless charging coil winding which comprises two or more layers of coils, the two or more layers of coils are stacked in the vertical direction, each coil comprises a first wire and a second wire which are arranged side by side in the horizontal direction, and the first wire and the second wire are wrapped with insulating layers. The first wire and the second wire surround multiple circles from outside to inside along the same axis from the same starting point, the first wire is located on the outermost circle, the first wire surrounds one circle more than the second wire, and inner ports are formed in the end, located on the inner circle, of the first wire and the end, located on the inner circle, of the second wire respectively; for two adjacent layers of coils, the front face of one coil right faces the back face of the other coil, the inner port of the first wire in one coil right faces the inner port of the second wire in the other coil, and the right-facing inner ports are electrically connected. The coil has the advantages of small coil resistance, small eddy-current loss, high efficiency, easy adjustment of coil inductance, low requirement on the inner diameter of the coil and the like.

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] Wireless charging technology, also known as inductive charging and contactless charging, is a new charging technology derived from wireless power transmission technology. It can be used in wireless charging devices that use the principle of near-field inductive conduction to transmit energy over short distances without contact, and is a new charging technology that transmits energy from the transmitter (power supply device) to the receiver (power-consuming device). The alternating current carried by the transmitting coil in the wireless charger generates a magnetic field, and through magnetic coupling, the receiving coil in the electronic device obtains the energy transmitted by the transmitting end. The energy received by the receiving end is used to charge the battery and to maintain the operation of the device itself.

[0003] Since wireless charging is based on the magnetic coupling between the transmitting coil and the receiving coil for energy transmission, there is a strong magnetic field between the transmitting coil and the receiving coil. The traditional wireless charging coil winding is made of a single strand of wire, and the wire width of the coil winding is relatively wide, so when the current passes through the coil winding, a large eddy current loss will be generated. In order to reduce resistance and loss, the improved technology is to use two or more strands of smaller wires in parallel to form a multi-layer coil winding, such as Figure 1 In this way, the current can pass through the gaps between the multiple wires, effectively increasing the cross-sectional area of ​​the wire through which the current flows, and reducing resistance and circulating current loss.

[0004] However, when the coil windings of two or more smaller-width wires are used, new problems arise. When the current I passes through the wireless charging coil, unlike the single-wire coil winding, the direction of the current I flowing through each wire in the multi-wire winding is the same. When the wireless charging coil is placed in a magnetic field, due to electromagnetic induction, induced currents I with different directions will be generated on both sides of the multi-wire winding. E , the principle diagram is as follows Figure 2 As shown, the proximity effect is generated, and the influence of the skin effect in the coil winding is superimposed, which will produce a large circulating current loss in the coil. The current flowing through the copper foil will be overloaded or too low, thereby reducing the utilization rate of the copper foil in the coil and shortening the service life of the coil and the copper foil.

[0005] The Chinese invention patent with the publication number CN 110289156 A discloses a coil winding, comprising: an insulating layer, a first part coil located on one side of the insulating layer, and a second part coil located on the other side of the insulating layer. The first part coil comprises a first section of wire, the second part coil comprises a second section of wire, both the first section of wire and the second section of wire have N slots, the first section of wire is divided into N+1 strands of first sub-wires by the N slots, and the second section of wire is divided into N+1 strands of second sub-wires by the N slots; the N+1 strands of first sub-wires are electrically connected to the N+1 strands of second sub-wires one-to-one to form N+1 pairs of sub-wires, and at least one cross structure is formed in the N+1 pairs of sub-wires.

[0006] However, the above scheme still has shortcomings: it only adjusts the number of strands of the sub-conductor in the wire, and the adjustment of the number of sub-conductor strands cannot affect the overall number of turns of the coil. Therefore, in order to achieve the target inductance value, it is necessary to make major adjustments to the coil inner diameter design, etc., and the radius and length of the coil are required to be high. Utility Model Content

[0007] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the utility model is that the existing wireless charging coil winding has large coil resistance, large eddy current loss, low efficiency, difficult adjustment of coil inductance, and high requirements on the inner diameter of the coil.

[0008] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0009] A wireless charging coil winding comprises two or more layers of coils, wherein the two or more layers of coils are stacked in a vertical direction, wherein the coil comprises a first wire and a second wire arranged side by side in a horizontal direction, wherein the first wire and the second wire are both wrapped with an insulating layer, wherein the first wire and the second wire are wound multiple times from the same starting point along the same axis from the outside to the inside, wherein the first wire is located in the outermost circle, and the first wire is wound one more time than the second wire, wherein the end of the first wire located in the inner circle and the end of the second wire located in the inner circle respectively form inner ports; for two adjacent layers of coils, the front side of one coil faces the back side of the other coil, the inner port of the first wire in one coil faces the inner port of the second wire in the other coil, and the facing inner ports are electrically connected.

[0010] Optionally, the end of the first wire located at the outer circle and the end of the second wire located at the outer circle are merged and extended outward to form an external port, and both the inner port and the outer port are provided with welding points and electroplating holes.

[0011] Optionally, the electroplated holes provided on the inner ports facing each other of two adjacent layers of coils face each other and are connected to each other.

[0012] Optionally, the diameter of the electroplated hole is 0.2 mm.

[0013] Optionally, the number of the first conductive wire and the second conductive wire is two or more, and the number is the same.

[0014] Optionally, the first wire and the second wire may be formed in a circular ring or an elliptical ring.

[0015] The beneficial effects of the utility model are: the first wire and the second wire are wound in parallel, which reduces the resistance and circulation loss; the first wire is located in the outermost circle and is wound one more circle than the second wire, the front and back sides of the coils of the two adjacent layers are opposite, the inner port of the first wire of one coil is directly opposite to the inner port of the second wire of the other coil and is electrically connected, forming a cross-series structure, reducing the circulation loss caused by the skin effect and the proximity effect, effectively improving the utilization rate of the copper foil in the coil, allowing the current to flow through the coil more evenly and stably, avoiding current overload or low current at different positions on the wire, reducing the coil circulation loss, and improving the efficiency of wireless charging. And the coil is easy to adjust the inductance to the required value, effectively preventing the coupling effect and charging efficiency from being affected by the small inner diameter of the coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure shows a schematic diagram of a coil winding structure of a single-strand wire structure in the prior art;

[0017] Figure 2 The figure is a schematic diagram showing the principle of generating an induced current in a coil winding of a multi-strand wire structure in the prior art;

[0018] Figure 3 The figure shows a coil structure schematic diagram of a wireless charging coil winding of an embodiment of the utility model;

[0019] Figure 4 Shown is another coil structure schematic diagram of the wireless charging coil winding of an embodiment of the utility model;

[0020] Figure 5 The figure shows a schematic diagram of the structure of the wireless charging coil winding of an embodiment of the utility model;

[0021] Figure 6 It is a schematic diagram showing the principle of generating induced current by the wireless charging coil winding according to an embodiment of the utility model.

[0022] Description of labels:

[0023] 1. First conductor; 2. Second conductor; 11, 12. Inner port; 3. Outer port; 41, 42. Inner ring welding port; 51, 52. Outer ring welding port. DETAILED DESCRIPTION

[0024] 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.

[0025] Please refer to Figure 3-6 As shown, the technical solution provided by the utility model is:

[0026] A wireless charging coil winding comprises two or more layers of coils, wherein the two or more layers of coils are stacked in a vertical direction, wherein the coil comprises a first wire and a second wire arranged side by side in a horizontal direction, wherein the first wire and the second wire are both wrapped with an insulating layer, wherein the first wire and the second wire are wound multiple times from the same starting point along the same axis from the outside to the inside, wherein the first wire is located in the outermost circle, and the first wire is wound one more time than the second wire, wherein the end of the first wire located in the inner circle and the end of the second wire located in the inner circle respectively form inner ports; for two adjacent layers of coils, the front side of one coil faces the back side of the other coil, the inner port of the first wire in one coil faces the inner port of the second wire in the other coil, and the facing inner ports are electrically connected.

[0027] From the above description, it can be seen that the coil is a spiral structure from the outside to the inside. Each turn of the coil on the outside is composed of the first wire and the second wire distributed in sequence, and the innermost turn of the coil only has the first wire, so the number of wire strands of the innermost turn of the coil is half of the number of wire strands of the other turns of the coil. This structure is simple and convenient to wind, and it is easy to adjust the coil inductance, and the inner diameter of the coil is small. The inner port of the wire is reserved for cross-series use. When the front and back sides of two adjacent layers of coils are opposite, a cross structure is formed on the vertical projection surface. By connecting the inner ports of the two adjacent layers of coils that are opposite to each other, the coil can be connected in series as a whole, thereby reducing the circulation loss and improving the efficiency of wireless charging.

[0028] Optionally, the end of the first wire located at the outer ring and the end of the second wire located at the outer ring are combined and extended outward to form an outer port, and both the inner port and the outer port are provided with welding points and electroplating holes. Preferably, multiple electroplating holes can be provided on one port to strengthen the electrical connection.

[0029] Optionally, the electroplated holes provided on the inner ports facing each other of two adjacent layers of coils face each other and are connected to each other.

[0030] From the above description, it can be known that the connection between the ports is achieved by setting welding points and electroplated holes. Specifically, the Hotbar welding method can be used to weld the inner ports of the upper and lower coils relative to each other.

[0031] Optionally, the diameter of the electroplated hole is 0.2 mm. The setting of the diameter of the electroplated hole is a preferred setting in the first embodiment.

[0032] Optionally, the number of the first conductive wire and the second conductive wire is two or more, and the number is the same.

[0033] From the above description, the number of strands of the first wire and the second wire can be multiple, such as 2 strands and 3 strands, so the total number of strands of the coil is 4 strands and 6 strands. If the total number of wires is 6 strands, they are numbered 1-1, 1-2, 1-3, 2-1, 2-2, 2-3 respectively. From the outside to the inside, for an n-turn coil, the distribution of the first turn to the n-1th turn of the coil is wire 1-1, 1-2, 1-3, 2-1, 2-2, 2-3, then the innermost turn of the coil is wire 1-1, 1-2, 1-3, and so on.

[0034] Optionally, the first wire and the second wire may be formed in a circular ring or an elliptical ring.

[0035] Please refer to Figure 3-6 , Embodiment 1 of the present utility model is:

[0036] A wireless charging coil winding includes two or more layers of coils, which are stacked in the vertical direction. The coil includes a first wire 1 and a second wire 2 arranged side by side in the horizontal direction, and the first wire 1 and the second wire 2 are both wrapped with an insulating layer. The first wire 1 and the second wire 2 are wound multiple times from the same starting point along the same axis from the outside to the inside to form a planar spiral structure. The first wire 1 is located in the outermost circle, and the first wire 1 is wound one more circle than the second wire 2, that is, the first wire 1 is also located in the innermost circle, and the innermost turn of the coil is only composed of the first wire 1, and the other turns of the coil are composed of the first wire 1 and the second wire 2 distributed in sequence from the outside to the inside. The shape of the first wire 1 and the second wire 2 is a circular ring.

[0037] The end of the first wire 1 located at the inner circle forms an inner port 11, the end of the second wire 2 located at the inner circle forms an inner port 21, the end of the first wire 1 located at the outer circle and the end of the second wire 2 located at the outer circle are combined and extended outward to form an outer port 3, and the inner port 11, the inner port 21 and the outer port 3 are all provided with welding points and electroplating holes. The diameter of the electroplating hole is 0.2 mm.

[0038] For two adjacent layers of coils, the front side of one coil faces the back side of the other coil, the inner port 11 of the first wire 1 in one coil faces the inner port 21 of the second wire 2 in the other coil, and the electroplated holes provided in the facing inner ports face each other and are connected to each other.

[0039] In a preferred configuration, the number of the first conductive wires and the second conductive wires is two or more, and the number is the same.

[0040] In this embodiment, the first conductive wire and the second conductive wire are the same conductive wire.

[0041] The following example is taken where the number of the first conductive wire and the number of the second conductive wire are 1 strand respectively, that is, the number of conductive wire strands is 2, the number of turns of the coil is 3, and the number of coils is 2.

[0042] like Figure 3 As shown, from the outside to the inside, the first turn of the coil and the second turn of the coil are composed of the first wire 1 and the second wire 2, and the third turn of the coil, that is, the innermost turn of the coil, is composed of the first wire 1. Figure 3 The coil is shown in front view.

[0043] like Figure 4 Shown is Figure 3 The coils have the same structure, but are placed on the opposite sides. Figure 5 The figure shows a wireless charging coil winding formed by stacking two coils, wherein the inner port 11 of the first wire 1 of one coil faces the inner port 21 of the second wire 2 of the other coil, and the inner ports facing each other of the two coils are electrically connected by welding and setting electroplated holes thereon to form a series cross, and two inner circle welding ports 41 and 42 are formed in the inner circle, and the outer ports 3 of the two coils serve as outer circle welding ports 51 and 52 respectively.

[0044] In the series cross structure, when the wireless charging coil winding is placed in the magnetic field, due to the gaps between the multiple wires, the magnetic field will generate induced currents in opposite directions in the first wire 1 and the second wire 2 of the coil, which can achieve mutual cancellation of some induced currents, weaken the influence of skin effect and proximity effect, improve the utilization rate of current on copper foil in the wire, significantly reduce the circulation loss in the coil winding, and improve the charging efficiency of the wireless charging coil. The schematic diagram of generating induced current is shown in the figure below. Figure 6 shown.

[0045] Table 1 below shows a performance test comparison between the coil winding of the prior art and the wireless charging coil winding of this embodiment.

[0046] Table 1

[0047]

[0048] As can be seen from Table 1, the wireless charging coil winding of the utility model embodiment effectively reduces the impedance and improves the charging efficiency of the wireless charging coil. The coil adopts the method of cross-connecting the wire ports in series to better optimize the coil impedance and charging efficiency.

[0049] In summary, the wireless charging coil winding of the utility model has the advantages of small coil resistance, small eddy current loss, high efficiency, easy adjustment of coil inductance, and low requirement on coil inner diameter.

[0050] The above-mentioned wireless charging coil winding can be manufactured by the following method:

[0051] Step 1: First, two coils are obtained by laser lithography, in which the first wire is wrapped one more circle than the second wire, and then the coils are subjected to baking varnish insulation treatment, and welding points and electroplating holes are opened at the inner and outer ports of the coils.

[0052] Step 2: stack the front side of one coil and the back side of the other coil, with the inner end of the first wire of one coil facing the inner end of the second wire of the other coil. Use the hotbar welding technology to connect the electroplated holes in the inner ends of the two coils facing each other.

[0053] It should be noted that the horizontal direction, vertical direction, front side and back side described in the present invention are only relative descriptions, and are not limitations to the present invention.

[0054] 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 coils, the two or more layers of coils are stacked in a vertical direction, the coil comprises a first wire and a second wire arranged side by side in a horizontal direction, the first wire and the second wire are both wrapped with an insulating layer, characterized in that: The first wire and the second wire are wound multiple times from the same starting point along the same axis from the outside to the inside, the first wire is located in the outermost circle, and the first wire is wound one more circle than the second wire, and the end of the first wire located in the inner circle and the end of the second wire located in the inner circle respectively form inner ports; for two adjacent layers of coils, the front side of one coil faces the back side of the other coil, the inner port of the first wire in one coil faces the inner port of the second wire in the other coil, and the facing inner ports are electrically connected.

2. The wireless charging coil winding according to claim 1, characterized in that: The end of the first wire located at the outer circle and the end of the second wire located at the outer circle are merged and extended outward to form an outer port. Both the inner port and the outer port are provided with welding points and electroplating holes.

3. The wireless charging coil winding according to claim 2, characterized in that: The electroplated holes provided at the inner ports facing each other of the coils of two adjacent layers face each other and are connected to each other.

4. The wireless charging coil winding according to claim 2, characterized in that: The diameter of the electroplated hole is 0.2 mm.

5. The wireless charging coil winding according to claim 1, characterized in that: The number of the first conductive wire and the second conductive wire is two or more, and the number is the same.

6. The wireless charging coil winding according to claim 1, characterized in that: The shapes of the first and second conductive lines include circular and elliptical shapes.

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