An electromagnetic coupling energy transmission device

Abstract

An electromagnetic coupling energy transmission device, characterized in that it has a coil module and an AC power conversion module; the coil module includes a spiral coil and a first soft magnetic material; the first outer contour of the projection of the spiral coil on the radial plane of the spiral coil is similar to a drum shape, and the first inner contour is similar to a rectangle. The length of the first outer contour is L and the width is W, the length of the first inner contour is a and the width is b, and the range of (π*r + arcsin((W - 2*r) / L)*L) / (a + b) is 0.9 to 1.2, where π is the value of the circumference ratio.

Description

Technical Field

[0001] The present invention relates to an electromagnetic coupling energy transmission device, in particular to a design scheme similar to a drum-shaped coiled spiral coil module. Background Art

[0002] Generally, an electromagnetic coupling energy transmission device, especially an electromagnetic coupling energy output device, that is, a commonly used wireless charger, will adopt a circular coil module with a diameter exceeding 40 mm or a rounded square coil module with a length and width exceeding 50 mm. This results in the inability to make the wireless charger product into a very narrow shape to wirelessly charge strip-shaped or electronic products with a very narrow charging surface, such as electric mops, small vacuum cleaners, massagers, and electronic pens.

[0003] For this reason, the inventor of the present application applied for the patent CN2021103294064 to protect a long strip-shaped horizontally wound coil module, so as to make the wireless charger product into a very narrow strip shape. However, in actual use, it is found that the decreasing trend of the coupling coefficient (Co-eff) VS coupling distance (Distance) of the CN2021103294064 technology is very obvious, that is, high-efficiency energy transmission can only be carried out at a very close distance. Moreover, when the electromagnetic coupling energy input device adopts a circular or square coil module with a diameter matching the coil length used in the CN2021103294064 technology, the coupled energy density is also small, that is, it cannot transmit a large amount of energy.

[0004] Therefore, it is necessary to further invent a coil module that not only maintains the long strip-shaped appearance unchanged, but also can provide higher energy for a circular or square coil module with a matching size, and realize that the decreasing trend of the coupling coefficient (Co-eff) VS coupling distance (Distance) is slow in a large range. Summary of the Invention

[0005] In order to achieve the above object, starting from the principle that electromagnetic coupling energy transmission realizes energy transmission through a closed alternating magnetic field, the inventor first increases the distance of the magnetic induction lines from the inner circle to the outer circle of the present invention coil on the first soft magnetic material beside the present invention coil, so as to increase the magnetic resistance of the corresponding magnetic circuit to increase the number of magnetic induction lines generated by the present invention coil that bypass the opposite coil winding and directly close, thereby realizing the purpose that the decreasing trend of the coupling coefficient (Co-eff) VS coupling distance (Distance) is slow in a large range. The opposite coil refers to the coil that interacts with the present invention coil to realize electromagnetic coupling energy transmission. Therefore, the following methods can all increase the magnetic resistance:

[0006] 1. The axial thickness t of the coil winding of the present invention is increased. Generally speaking, the larger t is, the better the effect is.

[0007] 2. The coil winding of the present invention increases the radial thickness f. Since the coil of the present invention is intended to be a long strip coil, if the present invention adopts the same transverse winding coil as CN2021103294064, the larger the f, the better; if the coil used in the present invention is a spiral coil with the rotation axis facing the electromagnetic coupling energy output / input direction, it is also necessary to subdivide the long side of the coil with a radial thickness of x and the short side of the coil with a radial thickness of y. The larger the x and y, the better the effect.

[0008] 3. The side of the first soft magnetic material close to the coil of the present invention is a plane or has an inclined surface that tends to move away from the coil of the present invention, or there is a gap with a distance d between the first soft magnetic material and the coil of the present invention. To ensure that the inductance change of the coil module is less than 20% to avoid affecting the working reliability of the device of the present invention, d≤(2t+x) / 3 or d≤(2t+y) / 3.

[0009] In simple terms, after the outer dimensions of the coil of the present invention are basically limited, the smaller the central hole of the spiral coil of the present invention is, the better the effect is.

[0010] However, when the distance between the coil of the present invention and the opposite coil is relatively far, the magnetic resistance of the transverse winding type coil facing the electromagnetic coupling energy transmission direction and the side away from the electromagnetic coupling energy transmission direction are relatively close, so there are also non-negligible closed magnetic flux lines on the side away from the electromagnetic coupling energy transmission direction, so the transverse winding type coil is abandoned. The following content will be developed around the horizontally wound spiral coil similar to the drum-shaped spiral coil with a central hole.

[0011] Secondly, since the opposite coil may be a common circular wound coil with a center hole of about 20 mm in diameter, and the distance e between the first soft magnetic material next to the spiral coil of the present invention and the third soft magnetic material next to the opposite coil is generally 2.5~7.5 mm, in order to reduce the magnetic flux lines generated by the winding near the center area of ​​the coil of the present invention, which pass through the third soft magnetic material next to the opposite coil and return to the coil of the present invention without cutting the winding of the opposite coil, thereby generating useless work, the diameter of the minimum inscribed circle of the center hole of the spiral coil of the present invention projected on the radial plane of the spiral coil of the present invention is ≥(20-2*2*e).

[0012] In short, if the center hole of the coil of the present invention is too small, the winding near the center will hinder the winding slightly closer to the outside, thereby reducing efficiency, being detrimental to electromagnetic coupling energy transmission, and of course being unable to provide high-power electromagnetic coupling energy. Therefore, the center hole needs to be as large as possible.

[0013] Furthermore, since ideal electromagnetic coupling energy transfer requires all magnetic induction lines to pass through the innermost circle of the opposite coil and then through the outermost circle, the effective area of the coil central hole (the magnetic induction line density within the range of 2 mm from the inner or outer edge of the coil accounts for 90% or more, so the area within this 2 mm range belongs to the effective area) needs to be very close to the effective area of the outer coil, especially the outer side of the short side. Therefore, through a large number of calculations and experiments by the inventor, combined with the experience of industrial mass production, a new coil model for an electromagnetic coupling energy transfer device is proposed:

[0014] 1. The first outer contour of the projection of the spiral coil on the radial plane is similar to a drum shape, and the first inner contour corresponding to the central hole is similar to a rectangle. The short side of the first outer contour includes a small arc with a radius of r connected to the long side and a large arc with a radius of R between the two small arcs. The length of the first outer contour is L and the width is W, the length of the first inner contour is a and the width is b, the radial thickness of the coil on the long side is x = (L - a) / 2, and the radial thickness of the coil on the short side is y = (W - b) / 2. And the range of (π*r + arcsin((W - 2*r) / L)*L) / (2a + 2b - 2*2) is 0.9 to 1.2, and the thickness of the spiral coil in the axial direction is t.

[0015] 2. To reduce the magnetic induction lines generated by the spiral coil of the present invention from cutting part of the windings of the opposite coil through the central hole and then winding back to the first soft magnetic material outside the long side of the spiral coil of the present invention, the shape of the first soft magnetic material can be designed to be close to the outer shape of the spiral coil, that is, the second outer contour of the projection of the first soft magnetic material on the radial plane of the spiral coil is similar to a drum shape, and a pair of opposite short sides of the drum shape are convex arcs, and the length D of the second outer contour ≥ (L + 1) mm, and the range of the width E is W to (W + 1) mm.

[0016] 3. Since the outer diameter of a common circular wound coil, especially a circular wound coil with a magnetic attraction function, is 40 to 41 mm and the outer diameter of the third soft magnetic material is 45 to 46 mm, the range of L is 38 to 42 mm, the range of W is 23 to 27 mm, the range of a is 22 to 26 mm, the range of b is 5 to 10 mm, and x ≥ (y - 1) mm; the radius R of the large arc ≥ 0.35*L, the radius r of the small arc ≤ 8 mm, and r / R ≤ 0.4.

[0017] 4. In the actual test of the inventor, the optimal numerical range of an outer-drum inner-rectangle single-layer planar wound coil is L = 40 to 41 mm, W = 24 to 26 mm, a = 22 to 24 mm, b = 8 to 10 mm, r = 5 to 6 mm, R > 40 mm, D = 45 to 46 mm, E = W, d ≤ 1.5 mm.

[0018] 5. In the 4th step, the inductance value of the coil module made of single-bundle multi-strand enameled wire by the conventional coil winding method is 6.1 - 6.5 μH. The actual coupling effect is about 15% short of the ideal effect. It is necessary to increase the number of turns of the spiral coil on the premise of keeping the radial dimension of the spiral coil unchanged and allowing a slight increase in the axial direction to increase the inductance value. Therefore, the present invention further uses multi-strand flat insulated metal foil or no less than one bundle of multi-strand enameled wire to wind the spiral coil, and the axial length i of the winding of more than half of the turns of the spiral coil is ≥ the radial length j. In this way, the number of turns of the coil is increased by 15 - 20%, and thus the inductance value is slightly increased to 7.9 - 8.4 μH, achieving the ideal effect. Especially when using multi-strand flat insulated metal foil to wind the spiral coil, the thickness t even decreases.

[0019] 6. When using the EMC type separated electromagnetic coupling energy transmission technology, in the case where a stable potential eddy current damper is designed beside the coil module, the stable potential eddy current damper is a continuous conductor with a relative magnetic permeability < 10, and is electrically connected to a stable level on the AC power conversion module through a high-frequency low-resistance conductor, or a high-frequency low-resistance circuit, or a combination of a high-frequency low-resistance conductor and a circuit; the stable potential eddy current damper is arranged on the A surface of the spiral coil, or on the B surface of the spiral coil, or on the surface of the first soft magnetic material away from the spiral coil, or a combination of the three setting methods; the projection of the stable potential eddy current damper on the radial plane of the spiral coil has a third outer contour and a third inner contour, and the third inner contour is located outside the first inner contour or the third inner contour coincides with the first inner contour, so that the eddy current loss generated by the alternating magnetic field generated by the working frequency of the spiral coil during operation on the stable potential eddy current damper can be greatly reduced; in order to further reduce the eddy current loss caused by the working frequency, there is an opening from the third inner contour to the third outer contour.

[0020] In short, the stable potential eddy current damper is a C-shaped non-magnetic conductive body close to the shape of the spiral coil.

[0021] 7. Considering that the opposite circular coil may have an opposite magnet structure, and the opposite magnet structure is generally annularly distributed with an inner diameter of 45-46 mm and an outer diameter of 54-56 mm, and the opposite magnet structure generally uses a planar bipolar magnet unit, the present invention also provides a magnet assembly with a matching position on the outer side of the spiral coil in the radial direction of the spiral coil, and also uses a bipolar magnet unit with a matching magnetic pole. Moreover, in order to reduce the strong magnetic induction lines of the magnet unit of the magnet assembly from interfering with the first soft magnetic material and causing the first soft magnetic material to become magnetically saturated, resulting in the inability to conduct the weak magnetic induction lines of the alternating magnetic field generated when the spiral coil operates with low magnetic resistance, the magnet unit of the magnet assembly of the present invention is provided with a second soft magnetic material on one side surface in the same direction as the B surface.

[0022] 8. Since the thickness needs to be controlled in the actual product, it is necessary to control the thickness t of the coil module in the axial direction. The lead of the spiral coil also passes through the first soft magnetic material and is led out from the other side of the first soft magnetic material, or the lead of the spiral coil passes through the gap between adjacent magnet units and is led out.

[0023] Finally, the designed coil module is electrically connected to the AC power conversion module to achieve the complete function. The AC power conversion module converts the first alternating current conducted on the coil into direct current or the second alternating current from the outside world. The first alternating current transmission end of the AC power conversion module is electrically connected to the spiral coil.

[0024] Through the above series of processes of reasoning, calculation, trial production, testing, and repeating many times, the following beneficial effects are finally achieved:

[0025] 1. Compared with the electromagnetic coupling energy output device made by the technology of CN2021103294064, the thickness of the coil module part is reduced by 50%, while the length and width remain basically unchanged.

[0026] 2. Compared with the electromagnetic coupling energy output device made by the technology of CN2021103294064, the energy output power is increased by 100%.

[0027] 3. Compared with the electromagnetic coupling energy output device made by the technology of CN2021103294064, the curve of the coupling coefficient (Co-eff) VS the coupling distance (Distance) decays more slowly, and the coupling efficiency is increased by more than 5%.

[0028] 4. Compared with the electromagnetic coupling energy output device made by the technology of CN2021103294064, the size range of the electromagnetic coupling energy input coil module adapted is increased by 200% - from an outer diameter of 25 mm to an outer diameter of 52 mm.

[0029] 5. Compared with the electromagnetic coupling energy output device manufactured by the technology of CN2021103294064, the materials of the coil module are saved by 70%, and the production efficiency is increased by 400%. Description of the Drawings

[0030] Figure 1 This is the first embodiment of the present invention.

[0031] Figure 2 This is the second embodiment of the present invention.

[0032] Figure 3 This is the third embodiment of the present invention.

[0033] Figure 4 This is the dimensional drawing of the first embodiment of the spiral coil, the matching first soft magnetic, and the matching stable potential eddy current damper of the present invention.

[0034] Figure 5 This is the first embodiment of the cross-section of the spiral coil winding of the present invention.

[0035] Figure 6 This is the second embodiment of the cross-section of the spiral coil winding of the present invention.

[0036] Figure 7 This is the first embodiment of the axial sectional view of the coil assembly of the present invention.

[0037] Figure 8 This is the second embodiment of the axial sectional view of the coil assembly of the present invention.

[0038] Figure 9 This is the relationship diagram of the coupling coefficient (Co-eff) VS coupling distance (Distance) between the coil assembly of the present invention and the coil assembly of CN2021103294064.

[0039] Figure 10 This is the relationship diagram of different center hole sizes VS coupling coefficient when the inner diameter of the center hole of the opposite coil is 20 mm and the coupling distance with the coil assembly of the present invention is 3 mm, and the outer dimensions of the spiral coil of the present invention remain unchanged.

[0040] Figure 11 This is the path of the magnetic induction lines of the winding near the inner circle when the inner diameter of the center hole of the opposite coil is relatively large, the distance between the opposite third soft magnetic material and the first soft magnetic material in the present invention is relatively close, and the center hole of the spiral coil of the present invention is relatively small. Detailed Embodiments

[0041] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention and do not limit the application scope of the present invention. For those of ordinary skill in the art, without creative efforts, the present invention can be applied to other similar scenarios based on these drawings; as shown in this specification and the claims, unless the context clearly indicates an exceptional situation, words such as "one", "a", "an", and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the term "comprising" or "including" only indicates the inclusion of the clearly identified steps and elements, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements. The term "based on" is "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment".

[0042] As Figure 1 、 Figure 2 、 Figure 3 shown, either the leads 11 and 12 of the spiral coil 1 pass through the first soft magnetic material 2, or the first soft magnetic material 2 and the stable potential eddy current damper 3, or pass between the magnet units 51 of the magnet assembly 5, and are electrically connected to the AC power conversion module 4. And the spiral coil 1 is in close contact with the first soft magnetic material 2, the stable potential eddy current damper 3 is in close contact with the first soft magnetic material 2, and a second soft magnetic material 6 is provided on the side of the magnet unit 51 facing the spiral coil 1 and close to the first soft magnetic material 2 in the same direction. In particular Figure 2 and Figure 3 , the leads 11 and 12 of the spiral coil 1 are electrically connected to the first AC power transmission end of the AC power conversion module 4 through the high-frequency low-resistance power cable 7, and the stable potential eddy current damper 3 is electrically connected to the stable level VEE of the AC power conversion module 4 through the conductor of the high-frequency low-resistance power cable 7. And Figure 2 and Figure 3 the distribution of the magnetic poles N and S of the magnet unit 51 in

[0043] As Figure 4 shown, one of the optimal embodiments of the spiral coil 1 and the first soft magnetic material 2 has dimensions of L = 40 - 41 mm, W = 24 - 26 mm, a = 22 - 24 mm, b = 8 - 10 mm, r = 5 - 6 mm, R > 40 mm, D = 45 - 46 mm, E = W. Furthermore, the optimal embodiment dimensions of the matching stable potential eddy current damper 3 are Lw = 55 - 56 mm, Ww = W, aw = a, bw = b.

[0044] Figure 5 and Figure 6Shown are two different ways of making the spiral coil 1, namely Figure 5 the winding method in which two bundles of multi-strand enameled wires are arranged side by side in the axial direction of the spiral coil 1, and Figure 6 the winding method of the multi-strand flat enameled metal foil.

[0045] Figure 7 And Figure 8 shows the relationships between two types of the first soft magnetic materials 2 and the spiral coil 1. Figure 8 In Figure 8 , the spacing d between the first soft magnetic material and the spiral coil 1 satisfies d ≤ (2t + x) / 3 or d ≤ (2t + y) / 3.

[0046] Figure 9 As shown, compared with the coupling coefficient (Co-eff) VS coupling distance (Distance) effect of the coil assembly (solid line) of the present invention and the coil assembly (dashed line) of CN2021103294064, there is an obvious improvement.

[0047] Figure 10 As shown, when the opposite coil has a common center hole with a diameter of 20 mm and a coupling distance of 3 mm from the spiral coil 1 of the present invention, there is a maximum value of the coupling coefficient (Co-eff) for different center hole sizes under the condition that the outer dimensions of the spiral coil 1 remain unchanged.

[0048] As Figure 11 shown, when the inner diameter of the center hole of the opposite coil 101 is relatively large and the third soft magnetic material 201 on one side of the opposite coil 101 is very close to the first soft magnetic material 2 on the other side of the spiral coil 1, if the center hole of the spiral coil of the present invention is relatively small, the magnetic induction lines 8 of the inner winding will not bypass the winding of the opposite coil, let alone pass through the complete opposite coil. Therefore, electromagnetic induction will not occur, and such windings do useless work, causing unnecessary copper loss and iron loss, and also interfering with the magnetic path of the magnetic induction lines of the slightly outer winding.

Claims

1. An electromagnetic coupling energy transmission device, characterized in that, It has a coil module and an AC power conversion module; The coil module includes a spiral coil and a first soft magnetic material; The spiral coil is a spiral coil with the rotation axis facing the electromagnetic coupling energy output / input direction. The first outer contour of the projection of the spiral coil on the radial plane of the spiral coil is similar to a drum shape, and the first inner contour is similar to a rectangle. The short side of the first outer contour includes a small arc with a radius of r connected to the long side and a large arc with a radius of R between the two small arcs. The length of the first outer contour is L and the width is W, the length of the first inner contour is a and the width is b, the radial thickness of the coil on the long side is x = (L - a) / 2, and the radial thickness of the coil on the short side is y = (W - b) / 2. The range of (π*r + arcsin((W - 2*r) / L)*L) / (a + b) is 0.9 to 1.2, where π is the value of pi. At the same time, the spiral coil also has an axial thickness t. The spiral coil has opposite A and B faces, the A face faces the electromagnetic coupling energy output / input direction, and the B face is closer to the first soft magnetic material; The projection of the first soft magnetic material on the radial plane of the spiral coil has a second outer contour similar to a drum shape, and a pair of opposite short sides of the drum shape are convex arcs. The range of the length D of the second outer contour is (L + 1) to 46 mm, and the range of the width E is W to (W + 1) mm; The range of L is 38 to 42 mm, the range of W is 23 to 27 mm, the range of a is 22 to 26 mm, and the range of b is 5 to 10 mm; The radius R of the large arc is ≥ 0.35*L, the radius r of the small arc is ≤ 8 mm, and r / R ≤ 0.4; The AC power conversion module is electrically connected to the coil, and converts the first alternating current conducted on the coil into direct current or a second alternating current from the outside. The first alternating current transmission end of the AC power conversion module is electrically connected to the spiral coil; The spiral coil is wound with multiple flat enameled metal foils or more than one bundle of stranded enameled wires. In the axial section of the spiral coil, the axial length i of more than half of the turns of the winding of the spiral coil is ≥ the radial length j.

2. The electromagnetic coupling energy transfer device according to claim 1, characterized in that, It has a stable potential eddy current damper and a high-frequency low-resistance power cable, The stable potential eddy current damper is a continuous conductor with a relative magnetic permeability < 10, and is electrically connected to a stable level VEE on the AC power conversion module through a high-frequency low-resistance conductor, or a high-frequency low-resistance circuit, or a combination of a high-frequency low-resistance conductor and a circuit; The stable potential eddy current damper is arranged on the A face of the spiral coil, or on the B face of the spiral coil, or on the side of the first soft magnetic material away from the spiral coil, or a combination of the three setting methods; The projection of the stable potential eddy current damper on the radial plane of the spiral coil has a third outer contour and a third inner contour, and the third inner contour is located outside the first inner contour or the third inner contour coincides with the first inner contour; There is an opening from the third inner contour to the third outer contour; The high-frequency low-resistance power cable is used for electrically connecting the first AC power transmission end of the AC power conversion module and the lead of the spiral coil, and one conductor in the high-frequency low-resistance power cable is electrically connected to the stable potential eddy current damper and a stable level VEE on the AC power conversion module.

3. The electromagnetic coupling energy transmission device according to claim 1, characterized in that, One side of the first soft magnetic material close to the spiral coil is a plane or has an inclined surface away from the spiral coil.

4. The electromagnetic coupling energy transmission device according to claim 1, wherein There is a gap d between the first soft magnetic material and the spiral coil, and d ≤ (2t + x) / 3 or d ≤ (2t + y) / 3.

5. The electromagnetic coupling energy transmission device according to claim 1, characterized in that, It has a magnet structure. The magnet structure includes at least a pair of magnet units. The projection of the magnet structure on the radial plane of the spiral coil is a third outer contour, and the third outer contour is located outside the pair of short sides of the second outer contour in the direction away from the axis of the spiral coil.

6. The electromagnetic coupling energy transfer device according to claim 5, characterized in that, At least a pair of the magnet units have two opposite magnetic poles on the surface substantially parallel to the radial plane of the spiral coil, which are magnetic pole A and magnetic pole B respectively, and magnetic pole A is closer to the axis of the spiral coil than magnetic pole B.

7. An electromagnetic coupling energy transmission device according to claim 1, characterized in that, Both leads of the spiral coil pass through the first soft magnetic material and are electrically connected to the AC power conversion module.

8. An electromagnetic coupling energy transmission device according to claim 5, characterized in that, The leads of the spiral coil are electrically connected to the AC power conversion module after passing through the gaps between the adjacent magnet units.

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