CN112233887B

CN112233887B - Wireless charging coil

Info

Publication number: CN112233887B
Application number: CN202010932364.9A
Authority: CN
Inventors: 陈勇; 胡永; 赵友姣
Original assignee: Shenzhen Sunlord Electronics Co Ltd
Current assignee: Shenzhen Shunluo Automotive Electronics Co ltd
Priority date: 2020-09-07
Filing date: 2020-09-07
Publication date: 2022-02-01
Anticipated expiration: 2040-09-07
Also published as: CN112233887A

Abstract

The application discloses wireless charging coil includes: the main coil is formed by enameled copper wires; the filling coil is arranged in a winding gap of the main coil in parallel and is formed by enameled copper wires, the thickness of each enameled copper wire forming the filling coil is smaller than that of each enameled copper wire forming the main coil, the common inner end of the main coil and the filling coil after being connected in parallel is a starting end, the outer end of the main coil and the filling coil is a stopping end, and the starting end and the stopping end are both used for being electrically connected with an external circuit board; set up the packing coil in the coiling clearance of main part coil, improved the space utilization of wireless charging coil, and the space that wireless charging coil occupied can not increase, consequently can reduce coil direct current resistance, promote the quality factor of coil under the prerequisite that does not increase wireless charging coil thickness for wireless charging coil has improved charge efficiency under frivolous prerequisite.

Description

Wireless charging coil

Technical Field

The application relates to the technical field of wireless charging, in particular to a wireless charging coil.

Background

The wireless charging technology is a technology for carrying out cable-free charging by using corresponding coils to transmit and receive induced alternating current signals at a transmitting end and a receiving end by using an electromagnetic induction principle.

In order to meet the user demand, a wireless charging terminal using a wireless charging technology is gradually developed toward a direction of being lighter and thinner and having high charging efficiency, and in order to achieve the purpose that the wireless charging terminal is lighter and thinner, the thickness direction of the coil needs to be thinner.

For wireless charging technology, a thinner and lighter design often requires a thinner coil thickness direction. In wireless charging systems, a high quality factor (Q) of the coil means high efficiency; q2 pi fL/Rac, where f denotes the coil operating frequency, L denotes the coil inductance, and Rac denotes the ac resistance at the coil operating frequency. Under the condition that the inductance L and the use frequency f of the coil are fixed, the coil resistance is inevitably increased due to the light and thin design, so that the quality factor Q of the coil is reduced, and the wireless charging efficiency is reduced.

However, in the existing wireless charging technology, the used coil is formed by winding a plurality of strands of copper wires with the same wire diameter, and in order to make the coil light and thin, only the wire diameter of the copper wire is reduced, and the high efficiency of coil charging is difficult to ensure after the wire diameter of the copper wire is reduced, so that the charging coil of the existing wireless charging technology cannot have high charging efficiency while being light and thin.

Disclosure of Invention

In view of this, the application provides a wireless charging coil to solve current wireless charging technology's charging coil and accomplish frivolous while, can't have the problem of higher charging efficiency.

The application provides a wireless charging coil, include: the main coil is formed by enameled copper wires; at least one kind sets up fill coil in the main part coil coiling clearance, just fill the coil with the parallelly connected setting of main part coil, fill the coil and constitute for the enameled copper line, and constitute the enameled copper line of filling the coil contains thick line footpath and is less than the constitution the enameled copper line of main part coil contains thick line footpath, the main part coil reaches the common interior tip of filling the parallelly connected back of coil is the initial end position, and the outer tip is the termination end position, initial end position reaches the termination end position all is used for being connected with external circuit board electricity.

The main body coil at least comprises two strands of enameled copper wires, all the enameled copper wires of the main body coil are arranged in parallel, and all the enameled copper wires of the main body coil are tangent to each other and have a circle center on the same straight line.

The main body coils are staggered and uniformly arranged in the thickness direction, and are arranged at intervals in a coplanar manner.

The filling coil at least comprises an enamelled copper wire strand, and all the enamelled copper wires are arranged in parallel.

Wherein, constitute respectively the main part coil with constitute the relation between the enameled copper wire line footpath of filling the coil satisfies:

arccos(d1/(d1+d2))＝arcsin((d1-d2)/(d1+d2))+arcsin((a-2d1)/2d1)

where d1 represents the thickness-containing wire diameter value of the enameled copper wire constituting the main coil, a is the maximum value in the thickness direction of the wireless charging coil, and d2 is the maximum value of the thickness-containing wire diameter of the enameled copper wire constituting the filler coil.

The outer surface of the enameled copper wire of the filling coil is tangent to the outer surfaces of all the adjacent enameled copper wires of the main coil.

Wherein the shape of the main body coil and the filling coil is circular, racetrack, oval or polygonal.

The enameled copper wire of the main coil and the enameled copper wire of the filling coil are self-adhesive enameled copper wires.

The enameled copper wire forming the main coil comprises a main copper wire and a main paint film; the enameled copper wire forming the filling coil comprises a filling copper wire and a filling paint film.

All the enameled copper wires forming the main coil and all the enameled copper wires forming the filling coil are arranged in parallel.

The foretell wireless charging coil of this application, through set up the packing coil in the coiling clearance of main part coil, the space utilization of wireless charging coil has been improved, and under the diameter of packing the coil was less than the diameter of main part coil's the condition, make the setting up of packing the coil can not increase the space that wireless charging coil occupied, consequently can be under the prerequisite that does not increase wireless charging coil thickness, reduce coil direct current resistance, promote coil quality factor, thereby make wireless charging coil under frivolous prerequisite, charging efficiency has been improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a wireless charging coil according to an embodiment of the present application;

FIG. 2 is a cross-sectional view taken along A-A of FIG. 1;

fig. 3 is a schematic structural view of a wireless charging coil of comparative case a;

fig. 4 is a sectional view taken along the direction B-B in fig. 3.

Detailed Description

The technical solutions in the embodiments of the present application are clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application. The following embodiments and their technical features may be combined with each other without conflict.

Referring to fig. 1 and 2, an embodiment of the present invention provides a wireless charging coil, including: a main body coil 3 and a fill coil 2; the main coil 3 is formed by enameled copper wires; the filling coil 2 is arranged in the winding gap of the main body coil 3 and is connected with the main body coil 3 in parallel; the filler coil 2 is also made of an enameled copper wire, but the diameter of the enameled copper wire constituting the filler coil 2 is smaller than the diameter of the enameled copper wire constituting the main coil 3.

In this embodiment, through set up packing coil 2 in main part coil 3's coiling clearance, wireless charging coil 1's space utilization has been improved, and under the condition that the diameter of packing coil 2 is less than main part coil 3's diameter, make setting up of packing coil 2 can not increase the space that wireless charging coil 1 occupied, consequently, can be under the prerequisite that does not increase wireless charging coil 1 thickness, wireless charging coil 1's direct current resistance has been reduced, wireless charging coil 1's quality factor has been increased, thereby make wireless charging coil 1 under frivolous prerequisite, charging efficiency has been improved.

In addition, in this embodiment, main part coil 3 is formed by four strands of enameled copper wire coiling, and the four strands of enameled copper wires of main part coil set up in parallel, and staggered uniform arrangement, two liang of interval coplane close-packed in the thickness direction of main part coil 3. The filling coil 2 is arranged in a gap of the main coil enameled copper wires in a staggered manner, the filling coil 2 is formed by winding three strands of enameled copper wires, and the three strands of enameled copper wires of the filling coil are arranged in parallel. All the enameled copper wires constituting the main body coil 3 are arranged in parallel with all the enameled copper wires constituting the filler coil 2.

As shown in fig. 2, for convenience of understanding, the enameled copper wire of the main coil 3 of the wireless charging coil 1 according to the present embodiment is divided into a first enameled copper wire 31 and a second enameled copper wire 32, a gap 33 exists between coils wound by the first enameled copper wire 31, a gap 34 exists between coils wound by the second enameled copper wire 32, a filling coil 2 exists in both the gap 33 and the gap 34, and the filling coil 2 is tangent to the first enameled copper wire 31 and the second enameled copper wire 32.

In other embodiments, the main coil 3 may be formed by winding at least two strands of enameled copper wires, the enameled copper wires forming the main coil 3 are all arranged in parallel, and are densely arranged in a single layer in parallel in the direction of the main coil 3, and all the enameled copper wires of the main coil are tangent to each other and have a center on a straight line. The filling coil 2 is arranged in a gap formed by arranging the enameled copper wires of the main body coil, the filling coil 2 can be formed by winding at least one enameled copper wire, and the number of strands of the filling coil 2 can be set according to the size of the winding gap of the main body coil 3 in specific application.

In order to reasonably utilize the winding gap of the main coil 3 and maximize the efficiency of the wireless charging coil 1, the film-containing thickness of the enameled copper wires forming the main coil 3 and the filling coil 2 should satisfy the relationship of formula 1, and formula 1 is expressed as follows:

arccos(d1/(d1+d2))＝arcsin((d1-d2)/(d1+d2))+arcsin((a-2d1)/2d1)

in equation 1, d1 represents the thickness-containing wire diameter value of the enameled copper wire constituting the main coil 3, a is the maximum value in the thickness direction of the wireless charging coil, and d2 is the maximum value of the thickness-containing wire diameter of the enameled copper wire constituting the filler coil 2.

Likewise, in order to make reasonable use of the winding gap of the body coil 3, thereby maximizing the efficiency of the wireless charging coil 1, the outer surface of the enameled copper wire filling the coil 2 is tangent to the outer surface of the enameled copper wire of the adjacent body coil 3.

In order to increase the variety of wireless charging coil 1 outward appearance to make wireless charging coil 1's suitability wider, main part coil 3 can be followed circular, runway type, oval or the fixed shape coiling of polygon and formed, and in this embodiment, main part coil 3 forms along circular coiling.

For the convenience of being fixed each other between the enameled copper wire that constitutes main part coil 3 and the enameled copper wire that constitutes packing coil 2, increase wireless charging coil 1's stability, the enameled copper wire that constitutes main part coil 3 and the enameled copper wire that constitutes packing coil 2 are self-adhesion type enameled copper wire, and the self-adhesion type enameled copper wire that this embodiment used is the hot melt self-adhesion enameled copper wire.

In this embodiment, in order to facilitate application or testing of the wireless charging coil 1, the inner end of the main coil 3 and the filler coil 2 connected in parallel is a start end, the outer end is a stop end, and both the start end and the stop end are used for being electrically connected to an external circuit or a circuit board.

In addition, the enameled copper wire forming the main coil 3 comprises a main copper wire and a main paint film, and the enameled copper wire forming the filler coil 2 comprises a filler copper wire and a filler paint film, wherein in the embodiment, the main copper wire, the main paint film, the filler copper wire and the filler paint film are respectively in wire diameter and paint film thickness; the wire diameter of the enameled copper wire forming the main coil 3 does not include the thickness of a paint film of the main copper wire; the wire diameter of the enameled copper wire constituting the filled coil 2 described above does not include the thickness of the filling paint film of the filled copper wire.

In order to better explain the technical scheme of the embodiment of the application, the embodiment also provides a case, namely a group of parameters are provided through an experiment, the experiment adopts two hot-melt self-adhesive enameled copper wires with different wire diameters, the hot-melt self-adhesive enameled copper wires are wound into a wireless charging coil 1 along a circle, the inner diameter of the whole wireless charging coil 1 is 20.5mm, and the number of coil turns of the wireless charging coil 1 is 15; the diameter of the enameled copper wire forming the main coil 3 is 0.125mm, the total thickness of the paint film is 0.008mm, the number of strands is four, the four enameled copper wires are uniformly arranged in a single-layer staggered manner, and every two enameled copper wires are spaced, coplanar and densely arranged; the diameter of the enameled copper wire forming the filling coil 2 is 0.08mm, the total thickness of a paint film is 0.01mm, and the number of strands is three; the enameled copper wires forming the filling coil 2 are positioned in the winding gaps of the enameled copper wires forming the main coil 3, and the sections of the enameled copper wires are tangent; the starting end position of the wireless charging coil 1 is arranged at the inner end part of the coil, the terminating end position is arranged at the outer end part of the coil, the starting end position and the terminating end position are used for being connected with an external test circuit or a test circuit board, and the external test circuit or the test circuit board is used for testing the inductance value, the direct current resistance, the alternating current resistance and the quality factor of the wireless charging coil 1. The results of the test are shown in table 1:

TABLE 1 Structure and Electrical parameters of the fill coil in the winding gap of the body coil

In addition, referring to fig. 3 and 4, the inventor found a comparison case a in the research process, that is, no filling coil is disposed in the winding gap of the main coil, and most of the thin wireless charging coil enameled copper wires in the prior art are arranged as shown in fig. 4, and the inventor conducted experiments and obtained data according to the comparison case a. The procedure of this experiment was as follows: the hot-melt self-adhesive enameled copper wire with the wire diameter of one specification is adopted and wound into a wireless charging coil 1 along a circle, the inner diameter of the whole wireless charging coil 1 is 20.5mm, and the number of coil turns of the wireless charging coil 1 is 15; the diameter of the enameled copper wire forming the main coil 1 is 0.125mm, the total thickness of the paint film is 0.008mm, the number of strands is four, the four enameled copper wires are arranged in a single-layer staggered and uniform mode, and every two enameled copper wires are spaced, coplanar and densely arranged. The starting end position of the wireless charging coil 1 is arranged at the inner end part of the coil, the terminating end position is arranged at the outer end part of the coil, the starting end position and the terminating end position are used for being connected with an external test circuit or a test circuit board, and the external test circuit or the test circuit board is used for testing the inductance, the direct current resistance, the alternating current resistance and the quality factor of the wireless charging coil. The results of the tests are shown in table 2:

TABLE 2 Structure and Electrical parameters of the main body coil without the Filler coil in the winding gap

As can be seen from comparison of data in tables 1 and 2, under the condition that the inner diameter, the outer diameter, the thickness and the inductance are substantially the same, the direct current resistance and the alternating current resistance of the wireless charging coil according to the embodiment of the present application are significantly lower than those of the wireless charging coil according to the comparative example, and the quality factor of the wireless charging coil according to the embodiment of the present application is significantly higher than that of the wireless charging coil according to the comparative example.

Although the application has been shown and described with respect to one or more implementations, equivalent alterations and modifications will occur to others skilled in the art based upon a reading and understanding of this specification and the annexed drawings. This application is intended to embrace all such modifications and variations and is limited only by the scope of the appended claims. In particular regard to the various functions performed by the above described components, the terms used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary implementations of the specification.

That is, the above description is only an embodiment of the present application, and not intended to limit the scope of the present application, and all equivalent structures or equivalent flow transformations made by using the contents of the specification and the drawings, such as mutual combination of technical features between various embodiments, or direct or indirect application to other related technical fields, are included in the scope of the present application.

In addition, in the description of the present application, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, should not be considered as limiting the present application. In addition, structural elements having the same or similar characteristics may be identified by the same or different reference numerals. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

In this application, the word "exemplary" is used to mean "serving as an example, instance, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. The previous description is provided to enable any person skilled in the art to make and use the present application. In the foregoing description, various details have been set forth for the purpose of explanation. It will be apparent to one of ordinary skill in the art that the present application may be practiced without these specific details. In other instances, well-known structures and processes are not shown in detail to avoid obscuring the description of the present application with unnecessary detail. Thus, the present application is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

Claims

1. A wireless charging coil, comprising:

the main coil is formed by enameled copper wires;

the filling coil is arranged in the winding gap of the main coil in parallel, the filling coil is formed by enameled copper wires, the thickness of the enameled copper wires forming the filling coil is smaller than that of the enameled copper wires forming the main coil, the inner end of the main coil and the filling coil after being connected in parallel is a starting end position, the outer end of the main coil and the filling coil is a terminating end position, and the starting end position and the terminating end position are both used for being electrically connected with an external circuit board;

the main coil at least comprises four strands of enameled copper wires, and all the enameled copper wires of the main coil are arranged in parallel, staggered and uniformly arranged in the thickness direction and arranged in a coplanar manner at intervals;

the enameled copper wire forming the main coil comprises a main copper wire and a main paint film;

the enameled copper wire forming the filled coil comprises a filled copper wire and a filled paint film;

the relationship between the diameters of the enameled copper wires respectively forming the main coil and the filling coil satisfies the following conditions:

arccos(d1/(d1+d2))＝arcsin((d1-d2)/(d1+d2))+arcsin((a-2d1)/2d1)

2. The wireless charging coil of claim 1,

the filling coil at least comprises an enamelled copper wire, and all the enamelled copper wires are arranged in parallel.

3. The wireless charging coil of claim 1,

4. The wireless charging coil of claim 1,

the main body coil and the filling coil are in a shape of a circle, a runway, an ellipse or a polygon.

5. The wireless charging coil of claim 1,

the enameled copper wire forming the main coil and the enameled copper wire forming the filling coil are self-adhesive enameled copper wires.

6. The wireless charging coil of claim 1,