A wireless charger and charging coil structure thereof

Abstract

The present invention discloses a wireless charger and a charging coil structure thereof. The charging coil structure includes a magnetic isolation sheet, on which a plurality of transmitting coils are arranged, and the transmitting coils are cross-stacked in at least two layers, and each transmitting coil intersects with at least two transmitting coils at the same time. The present invention uses a cross-stacked coil structure, so that the electronic terminal can be effectively charged regardless of where it is placed in the wireless charger component during charging, and intelligent charging positioning is realized. In addition, the cross-arrangement of the coils is also conducive to increasing the charging area, which can solve the problem of difficult alignment of traditional wireless charging.

Description

Technical Field

[0001] The present invention relates to wireless charging equipment, and in particular to a wireless charger and a charging coil structure thereof. Background Art

[0002] Wireless chargers use electromagnetic induction technology to charge electronic terminals. They do not require power cords, rely on electromagnetic wave propagation, and then convert electromagnetic wave energy into electrical energy, ultimately achieving wireless charging.

[0003] Existing wireless chargers can generally only charge one electronic terminal at a time. In order to enable the wireless charger to charge multiple terminals at the same time and to freely place electronic terminals, a multi-coil flat structure can be used.

[0004] The existing charging coil structure is as follows Figure 1 As shown in the figure, the inner diameter of a single coil is 5mm and the outer diameter is 40mm. The inner diameter of the coil is small, and generally a layer of flat structure is adopted, and adjacent coils are arranged closely. After the charger is powered on, the current flows through the coil and generates an induced magnetic field around the coil. Since the directions of the magnetic field lines of adjacent wires are opposite (such as Figure 2 As shown), it will cause the coil Routside-Rinside (as shown Figure 1 ) area. In other words, in the area from the outer diameter to the inner diameter of the coil, the magnetic fields generated by the coil will cancel each other out. The larger this area is, the larger the blind area of ​​the coil is, and its charging efficiency is low.

[0005] Some wireless chargers use a two-layer stacked structure, and the number of coil turns in each layer is the same. Since the distances between each layer of coil and the magnetic isolation sheet are different, the actual feel of the upper and lower layers of coils will be different, resulting in poor consistency of each layer of coils, which makes it difficult to control the wireless charging power transmission.

[0006] Therefore the prior art still needs to be improved and enhanced. Summary of the invention

[0007] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a wireless charger and a charging coil structure thereof, which can improve wireless charging efficiency and intelligent charging positioning.

[0008] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0009] A charging coil structure of a wireless charger comprises a magnetic isolation sheet, on which a plurality of transmitting coils are arranged, the transmitting coils are cross-stacked in at least two layers, and each transmitting coil intersects with at least two transmitting coils at the same time.

[0010] As an improvement of the present invention, the transmitting coils are laid out in more than three layers, and each transmitting coil intersects with at least three coils at the same time.

[0011] As an improvement of the present invention, the inductance of the transmitting coil decreases from the lower layer to the upper layer. As an improvement of the present invention, the outer diameter of the transmitting coil is 2-4 times the inner diameter.

[0012] As a further improvement of the present invention, the transmitting coils are arranged in three rows, and the transmitting coils in each row are evenly arranged.

[0013] As a further improvement of the present invention, the transmitting coils in the first row are arranged symmetrically with the third row, and the transmitting coils in the second row intersect with the transmitting coils around them.

[0014] As a further improvement of the present invention, the number of transmitting coils in the middle layer and the lower layer are 7, and the number of transmitting coils in the upper layer is 8.

[0015] As a further improvement of the present invention, the number of transmitting coils in the upper layer and the middle layer are both 6, and the number of transmitting coils in the lower layer is 7.

[0016] As a further improvement of the present invention, the transmitting coils of each layer are arranged at intervals, and the line connecting the center points of three adjacent transmitting coils forms an equilateral triangle.

[0017] The present invention also provides a wireless charger, comprising a shell, wherein a charging coil structure is arranged in the shell.

[0018] Compared with the prior art, the charging coil structure of the wireless charger provided by the present invention includes a magnetic isolation sheet, on which a plurality of transmitting coils are arranged, and the transmitting coils are cross-stacked in at least two layers, and each transmitting coil intersects with at least two transmitting coils at the same time. The present invention uses a cross-stacked coil structure, so that the electronic terminal can be effectively charged regardless of where it is placed in the wireless charger component during charging, thereby realizing intelligent charging positioning, and the cross-setting of multiple layers of coils is also conducive to improving charging efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of an existing charging coil.

[0020] Figure 2 Schematic diagram of how the magnetic fields of adjacent wires cancel each other out when an existing wireless charger has multiple charging coils.

[0021] Figure 3 A schematic structural diagram of a charging coil structure of a wireless charger provided in a first preferred embodiment of the present invention.

[0022] Figure 4 for Figure 3 Schematic diagram of the cross-sectional structure at AA in the middle.

[0023] Figure 5A schematic diagram of the arrangement of the first layer of transmitting coils in the charging coil structure of the wireless charger provided by the first preferred embodiment of the present invention.

[0024] Figure 6 A schematic diagram of the arrangement of the third layer of transmitting coils in the charging coil structure of the wireless charger provided in the first preferred embodiment of the present invention.

[0025] Figure 7 A schematic diagram of the arrangement of the second layer of transmitting coils in the charging coil structure of the wireless charger provided in the first preferred embodiment of the present invention.

[0026] Figure 8 A schematic structural diagram of a transmitting coil of the charging coil structure of the wireless charger provided by the present invention.

[0027] Fig. 9 A schematic structural diagram of a charging coil structure of a wireless charger provided in a second preferred embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0029] It should be noted that when a component is referred to as being "mounted on", "fixed on" or "disposed on" another component, it may be directly on the other component or there may be a central component at the same time. When a component is referred to as being "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time.

[0030] It should also be noted that the directional terms such as left, right, up, and down in the embodiments of the present invention are merely relative concepts or are based on the normal use status of the product and should not be considered as restrictive.

[0031] See also Figure 3 and Figure 4 The charging coil structure of the wireless charger provided by the first preferred embodiment of the present invention comprises a magnetic isolation sheet 1, on which a plurality of transmitting coils 2 are arranged, and the transmitting coils 2 are cross-stacked in at least two layers, and the first transmitting coil 2 is cross-stacked with at least two transmitting coils at the same time, so that each area facing the magnetic isolation sheet is laid with coils. The present invention uses a multi-layer cross-stacked coil structure, so that when charging, the electronic terminal can be effectively charged by the transmitting coil 2 no matter where it is placed in the wireless charger, thereby realizing intelligent charging positioning, and the cross-setting of the multi-layer coils makes the magnetic lines of force of the upper and lower coils have the same direction, which is also conducive to improving the charging efficiency.

[0032] Preferably, the transmitting coils 2 are laid in more than three layers, and each transmitting coil 2 intersects with at least three coils at the same time, that is, at least four coils intersect in each area facing the direction of the magnetic isolation sheet 1 (perpendicular to the viewing angle of the magnetic isolation sheet 1), so that the coils are laid as densely as possible, further facilitating intelligent positioning of charging.

[0033] The inductance of the transmitting coil 2 decreases from the lower layer to the upper layer. In other words, the number of turns of the transmitting coil 2 increases by one turn from the lower layer to the upper layer. Therefore, under the action of the magnetic isolation sheet 1, the inductance of each layer of coils is the same when working, so that the wireless charging power can be transmitted stably, which is beneficial to the control of the charging power.

[0034] In an optional embodiment, the transmitting coil 2 adjacent to the magnetic isolation sheet 1 (i.e., the lower layer) is the first layer, the transmitting coil 2 in the middle is the second layer, and the transmitting coil 2 on the top is the third layer. Among them, the first layer transmitting coil 2 (21) has 8 turns of winding, and its inductance is about 6.4μH, the second layer transmitting coil 2 (22) has 9 turns of winding, and its inductance is about 6.5μH, and the third layer transmitting coil 2 (23) has 10 turns of winding, and its inductance is about 6.8μH. It can balance the influence of adding the magnetic isolation sheet 1 on the actual inductance of the coil, so that the inductance of each layer of transmitting coil 2 plus the magnetic isolation sheet 1 is the same, so that the coil can be matched with the same set of capacitors to form an LC circuit. If the inductance of each layer of coils on the QI magnetic isolation sheet 1 is different, it is necessary to match capacitors of different capacitances to match the LC circuit, which increases the product cost, and it is also easy to make mistakes in materials (i.e., capacitors) during production. At this time, the inductance of each layer of coils is equal and it is easier to perform RX detection (i.e., wireless charging reception detection).

[0035] The present invention balances the difference in inductance of each layer of coils by making the number of turns of each layer of transmitting coils 2 different, greatly reducing the difficulty of controlling the wireless charging energy of the coils, facilitating power control and power value detection of wireless charging, and playing a key role in wireless current limiting control and other links.

[0036] See also Figure 5 , Figure 6 and Figure 7 In the charger coil structure of the present invention, the transmitting coils of each layer are arranged at intervals, the line connecting the center points of three adjacent transmitting coils forms an equilateral triangle, and each layer of transmitting coils 2 almost covers the entire area of ​​the magnetic isolation plate 1, so that the charging power of each area is basically equal.

[0037] In this embodiment, there are 7 transmitting coils in the middle and lower layers, and 8 transmitting coils in the upper layer. By stacking 22 coils regularly, the transmitting coils are evenly distributed on the magnetic isolation sheet 1. When charging, the electronic terminal can be placed in any position and charged by the coil, thus realizing intelligent positioning, so that the charging coil structure can be charged at any time.

[0038] Please continue reading Figure 3 and Figure 4 According to the viewing angle perpendicular to the magnetic isolation sheet 1, the transmitting coils 2 are arranged in three rows, and the transmitting coils 2 in each row are evenly arranged, and the transmitting coils 2 in two adjacent rows are arranged in an intersecting manner, so that the transmitting coils 2 are evenly distributed on the magnetic isolation sheet 1, so that when a receiving coil load (i.e., an electronic terminal to be charged) is placed at any position of the entire charging coil structure, there is a corresponding coil that can match it and charge it.

[0039] In this embodiment, the transmitting coils 2 in the first row and the transmitting coils 2 in the third row are arranged symmetrically up and down, and the transmitting coils 2 in the second row intersect with the transmitting coils 2 around them (that is, the transmitting coils 2 in the first and third rows), that is, each transmitting coil 2 in the second row intersects with the transmitting coils adjacent to it above, below, left and right, so that the coils are laid evenly.

[0040] The transmitting coils 2 in the first row can also be understood as the transmitting coils on the upper side of the charging coil structure, the transmitting coils 2 in the second row can also be understood as the transmitting coils in the middle of the charging coil structure, and the transmitting coils 2 in the third row can also be understood as the transmitting coils on the lower side of the charging coil structure. Each row of transmitting coils 2 includes three layers of coils: upper, middle, and lower. This makes the transmitting coils 2 of the wireless charger evenly and densely distributed, and each transmitting coil 2 intersects with at least three transmitting coils at the same time. Therefore, when a terminal to be charged is placed at any position of the wireless charger, it can be charged with the same power, thus realizing intelligent and precise positioning charging, that is, charging can be performed at any time, and the charging power at any position is the same.

[0041] like Figure 3 As shown, there are 7 transmitting coils 2 in the first and third rows, and 8 transmitting coils 2 in the second row. By stacking 22 coils, any position of the charging coil structure where a receiving coil load is placed has a corresponding transmitting coil 2 to match it, thereby realizing intelligent charging positioning and enabling the charging coil structure to be charged whenever it is placed.

[0042] like Figure 3-Figure 7 As shown, in the charging coil structure of the wireless charger of the present invention, in each layer of the transmitting coil 2, the adjacent transmitting coils are arranged at intervals, such as 3-5mm, so as to avoid the magnetic fields of the adjacent transmitting coils 2 from canceling each other during the charging process, thereby improving the charging efficiency. More preferably, during charging, when the transmitting coil senses an electronic device, the present invention can quickly locate and control the corresponding transmitting coil to work, and control the transmitting coil adjacent to it not to work, while realizing intelligent alignment and positioning, avoiding the magnetic fields canceling each other due to the adjacent coils working at the same time, and fewer coils working are also conducive to less heat generation, low power, energy saving and environmental protection of the wireless charger. Since the method of controlling the working state of the coil is a function that can be realized by existing software, the present invention will not elaborate on this.

[0043] Please continue reading Figure 4 The charging coil structure of the wireless charger of the present invention is provided with a heat sink 3 on the lower side of the magnetic isolation sheet 1. The heat sink 3 can be a metal sheet with high heat dissipation performance such as an iron sheet or an aluminum sheet. During the charging process, the heat of the transmitting coil 2 is quickly dissipated, so that when charging multiple electronic products at the same time, the heat sink 3 can dissipate heat evenly and quickly to avoid the charger temperature being too high.

[0044] In this embodiment, the magnetic isolation sheet 1 and the heat sink 3 are both waist-shaped, and the transmitting coil 2 is circular, regular polygonal, rectangular or elliptical. The elliptical magnetic isolation sheet 1 is covered with the transmitting coil 2 by overlapping three layers, so that the distance between the transmitting coil 2 located on the outer circle and the edge of the magnetic isolation sheet 1 can be within 5 mm, so that there is no wasted space on the magnetic isolation sheet 1, and the wireless charger can be set to a waist shape, which is beautiful and elegant in appearance.

[0045] In the specific implementation, the present invention adopts a circular transmitting coil 2, and when 22 coils are evenly arranged, it is more conducive to the same charging power in each area, and the waist-shaped magnetic isolation sheet 1 can charge three or even more electronic terminals at the same time, thereby greatly reducing the user's purchase cost. Of course, in other embodiments, the number and number of layers of the transmitting coil 2 can also be changed, such as a four-layer coil structure, and the present invention does not limit this, as long as the intelligent charging positioning and easy control of the charging power are satisfied.

[0046] Furthermore, semicircular notches 11 are provided at both ends of the magnetic isolation sheet 1, which are adapted to screws to facilitate its assembly with the shell of the wireless charger. The semicircular notches 11 can save installation space of the magnetic isolation sheet 1, which is conducive to the miniaturization of the wireless charger and further improves the appearance of the wireless charger.

[0047] In an optional embodiment, the outer diameter R of the transmitting coil 2 is 外 Inner diameter R 内 The diameter of the central hole of the transmitting coil 2 is 2-4 times of the diameter of the entire coil, that is, the central hole of the transmitting coil 2 is 0.25-0.5 times of the diameter of the entire coil, that is, the central hole of the transmitting coil 2 is larger than that of the prior art, thereby avoiding the magnetic field cancellation of two adjacent coils. For example, the inner diameter of the transmitting coil 2 of the present invention can be set to 25-30 mm, and the outer diameter is 40-45 mm. Compared with the existing transmitting coil 2, the inner diameter of the transmitting coil 2 is greatly enlarged (from Figure 8 and Figure 2 When the outer diameter remains unchanged, R 外 -R 内 The area is greatly reduced, which reduces the blind area of ​​the magnetic field and increases the effective induction area of ​​a single coil. Therefore, when each layer of coils is combined together, its induction blind area is greatly reduced. Then the blind area of ​​the entire charging coil structure will also be greatly reduced, which is more conducive to the charging panel of the wireless charger and can be charged at any position.

[0048] Preferably, the outer diameters of the transmitting coils are the same, and the inner diameters decrease from top to bottom. For example, the inner diameter of the lower transmitting coil is 0.5-3 mm smaller than that of the upper transmitting coil, so that the magnetic field strength decreases from top to bottom, which is beneficial for each layer of coils to have equal transmitting power after balancing the magnetic isolation sheets.

[0049] Since the number of turns of each layer of transmitting coils is different, the present invention makes the coils evenly stacked, the outer diameters of the transmitting coils are the same, and the inner diameters of each layer of transmitting coils 2 increase from the lower layer to the upper layer, which ensures even stacking and makes the inductance of each layer of coils the same after the balanced magnetic isolation sheet 1 is installed. For example: the present invention can set the outer diameter of the transmitting coil 2 to 41mm, the inner diameter of the lower layer transmitting coil to 24mm, the inner diameter of the middle layer transmitting coil to 24.3mm, and the inner diameter of the upper layer transmitting coil to 24.6mm, so that the inductance of the coil is smaller than that of the existing transmitting coil, and the inner diameter is also larger than that of the existing transmitting coil, so that the magnetic flux will increase, thereby greatly improving the charging efficiency.

[0050] Furthermore, the conductor wound around the transmitting coil 2 is a multi-strand enameled wire, the number of the conductor strands is 40 to 95, and the cross-section is flat, thereby increasing the charging output power and improving the charging efficiency.

[0051] Furthermore, the wires of the transmitting coil 2 are led out from the long side of the magnetic isolation sheet 1 and a regular lead-out position is also adopted, so that the charging current direction of each coil in the same group of drivers can be consistent, thereby suppressing the voltage of the non-working transmitting coil and better protecting the wireless charger.

[0052] See also Fig. 9 , which is a schematic diagram of the structure of the charging coil structure of the wireless charger provided by the second preferred embodiment of the present invention. The only difference between the second preferred embodiment and the first preferred embodiment is that the number of layers on the same magnetic isolation sheet is different. For example, the charging coil structure is composed of 19 coils, of which the upper and middle layers have 6 transmitting coils and the lower layer has 7 transmitting coils. The two adjacent coils in each layer are arranged tangentially, and the size and wire diameter of the coils can also be slightly adjusted as needed. This embodiment uses fewer coils, and also realizes the functions of uniform coil distribution and automatic positioning, and also saves material costs. When charging, it is only necessary to position and control the corresponding transmitting coil to work, and control the transmitting coils adjacent to it not to work. This method is described in detail above and will not be repeated here.

[0053] Based on the above charging coil structure, the present invention further provides a wireless charger, which includes a housing, wherein the above charging coil structure is disposed in the housing. Since the charging coil structure has been described in detail above, it will not be described in detail here.

[0054] In summary, the present invention uses a three-layer cross-stacked coil structure, so that when charging, the electronic terminal can be effectively charged no matter where it is placed in the wireless charger component, thereby realizing intelligent charging positioning, and the cross-setting of the three-layer coil is also conducive to improving the charging efficiency.

[0055] At the same time, the present invention balances the difference in inductance of each layer of coils by making the number of turns of each layer of transmitting coils different, greatly reducing the difficulty of controlling the wireless charging energy of the coils, so as to facilitate the power control and power value detection of wireless charging, and play a key role in wireless current limiting control and other links.

[0056] In addition, the present invention expands the inner diameter of the coil while keeping the outer diameter of the coil unchanged, thereby increasing the effective induction area of ​​a single coil. As a result, after each layer of coils is combined together, the induction blind area is greatly reduced. Then, the blind area of ​​the entire charging coil structure is also greatly reduced, which is more conducive to the charging panel of the wireless charger being placed and charged at any position.

[0057] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, and all these changes or substitutions should fall within the protection scope of the claims attached to the present invention.

Claims

1. A charging coil structure of a wireless charger, comprising a magnetic isolation sheet, on which a plurality of transmitting coils are arranged, characterized in that: The transmitting coils are cross-stacked in at least two layers, and each transmitting coil intersects with at least two transmitting coils at the same time; the transmitting coils are laid in more than three layers, and each transmitting coil intersects with at least three coils at the same time; the transmitting coils adjacent to the magnetic isolation sheet are the first layer, the transmitting coils in the middle are the second layer, and the transmitting coils on the top layer are the third layer; the transmitting coils in the first layer have 8 turns of winding, and their inductance is 6.4μH, the transmitting coils in the second layer have 9 turns of winding, and their inductance is 6.5μH, and the transmitting coils in the third layer have 10 turns of winding, and their inductance is 6.8μH, which can balance the influence of the magnetic isolation sheet on the actual inductance of the coils, so that the inductance of each layer of transmitting coils with the magnetic isolation sheet is the same; The outer diameters of the transmitting coils are the same, and the inner diameters decrease from top to bottom. The inner diameter of the lower transmitting coil is 0.5-3mm smaller than that of the upper transmitting coil. The outer diameter of the transmitting coil is set to 41mm, the inner diameter of the lower transmitting coil is set to 24mm, the inner diameter of the middle transmitting coil is set to 24.3mm, and the inner diameter of the upper transmitting coil is set to 24.6mm, so that the magnetic field strength decreases from top to bottom. The wires of the transmitting coils are led out from the long side of the magnetic isolation sheet, so that the charging current direction of each coil in the same group of drivers is consistent. Semicircular notches cooperating with the screws are arranged at both ends of the magnetic isolation sheet, and a heat sink for rapidly dissipating the heat of the transmitting coil during charging is arranged on the lower side of the magnetic isolation sheet.

2. The charging coil structure of the wireless charger according to claim 1, characterized in that: The transmitting coils are arranged in three rows, and the transmitting coils in each row are evenly arranged.

3. The charging coil structure of the wireless charger according to claim 2, characterized in that: The transmitting coils in the first row are arranged symmetrically with the third row, and the transmitting coils in the second row intersect with the transmitting coils around them.

4. The charging coil structure of the wireless charger according to claim 3, characterized in that: There are 7 transmitting coils in the middle and lower layers, and 8 transmitting coils in the upper layer.

5. The charging coil structure of the wireless charger according to claim 3, characterized in that: There are 6 transmitting coils in the upper and middle layers, and 7 transmitting coils in the lower layer.

6. The charging coil structure of the wireless charger according to claim 4, characterized in that: The transmitting coils of each layer are arranged at intervals, and the line connecting the center points of three adjacent transmitting coils forms an equilateral triangle.

7. A wireless charger, comprising a housing, characterized in that: The shell is provided with a charging coil structure as described in any one of claims 1 to 6.

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