JP4835786B1 - Non-contact charging module and non-contact charging device - Google Patents

Abstract

In a non-contact charging module having a flat coil portion formed of a spiral electric wire portion and a magnetic sheet, the non-contact charging is performed in a state where a sufficient cross-sectional area of the flat coil portion is secured to improve power transmission efficiency. An object of the present invention is to provide a non-contact charging module and a non-contact charging device that make the module smaller and thinner.
A planar coil part 2 in which a plurality of conductive wires are wound in a spiral shape and a magnetic sheet provided so as to face a surface of a coil 21 of the planar coil part 2 are provided. The planar coil part 2 is a non-contact charging module characterized in that a part of the planar coil part 2 is wound in a plurality of stages and the other part is wound in a single stage. .
[Selection] Figure 2

Description

  The present invention relates to a non-contact charging module having a planar coil portion made of a spiral conductive wire and a magnetic sheet, and a non-contact charging device using the same.

  In recent years, many devices that can charge the main device in a non-contact manner with a charger have been used. In this method, a power transmission coil is arranged on the charger side, a power reception coil is arranged on the main device side, and electromagnetic induction is generated between the two coils to transmit power from the charger side to the main device side. It has also been proposed to apply a mobile terminal device or the like as the main device.

  The main device such as the portable terminal device and the charger are required to be thin and small. In order to meet this demand, it is conceivable to provide a planar coil portion as a power transmission coil or a power reception coil and a magnetic sheet as in (Patent Document 1).

JP 2006-42519 A

  However, in the non-contact charging module provided with a single flat coil portion and a magnetic sheet with a flat surface as in (Patent Document 1), in order to ensure the necessary cross-sectional area of the conductive wire of the flat coil portion, The diameter is increased, and the thickness reduction is prevented accordingly. This is because when the cross-sectional area of the coil is reduced, the AC resistance ACR of the coil is increased, and the transmission efficiency of the non-contact charging module is reduced. Therefore, generally, the coil needs to have a diameter of at least about 0.25 mm, and when combined with the magnetic sheet, the thickness becomes very large.

  Therefore, in view of the above problems, the present invention provides a non-contact charging module capable of reducing the thickness of the non-contact charging module in a state in which the cross-sectional area of the planar coil portion is sufficiently secured and the power transmission efficiency is improved. An object is to provide a non-contact charging device.

In order to solve the above-described problems, the present invention places a planar coil portion in which a plurality of conductive wires are spirally wound, and a coil surface of the planar coil portion, and faces the coil surface of the planar coil portion. And the plurality of conductors are connected to each other at both ends thereof, and the planar coil portion is wound with a part thereof being stacked in a plurality of stages. parts and wound at one stage, the magnetic sheet, in a portion opposed to the portion that is wound on top in a plurality of stages of the planar coil portion, an annular recess or slit as thinning the magnetic sheet The non-contact charging module is characterized in that the plurality of conductive wires are housed inside the annular recess .

  According to the present invention, it is possible to reduce the size and thickness of the contactless charging module in a state where the cross-sectional area of the planar coil portion is sufficiently secured and the power transmission efficiency is improved.

Assembly drawing of contactless charging module in an embodiment of the present invention The conceptual diagram of the non-contact charge module in the Example of this invention The conceptual diagram which shows how to wind the coil of the non-contact charge module in the Example of this invention The conceptual diagram of the magnetic sheet of the non-contact charge module in the Example of this invention The top view of the magnetic sheet of the non-contact charge module in the example of the present invention The figure which shows the relationship between the thickness of the ferrite sheet of the non-contact charging module in Example of this invention, and the L value of a coil The figure which shows the relationship between the internal diameter and L value of the coil of the non-contact charge module in the Example of this invention. The figure which shows the relationship between the number of turns of the coil of the non-contact charge module in an Example of this invention, and L value

The invention according to claim 1 is provided such that a planar coil portion in which a plurality of conductive wires are wound in a spiral shape and a coil surface of the planar coil portion are placed and face the coil surface of the planar coil portion. and a magnetic sheet that is, the plurality of conductors are respectively connected at both ends to each other, the planar coil portion is wound partially overlapping in a plurality of stages, a portion of the other and wound in one step, the magnetic sheet, in a portion opposed to the portion that is wound on top in a plurality of stages of the planar coil portion, an annular recess or slit as thinning the magnetic sheet, the A non-contact charging module characterized in that the plurality of conductors are housed in an annular recess, and the non-contact charging is performed in a state in which the cross-sectional area of the planar coil portion is sufficiently secured to improve power transmission efficiency. Making modules smaller and thinner Door can be.

  The invention according to claim 2 is characterized in that the planar coil portion is wound with a plurality of inner sides thereof wound, and the remaining outer side is wound in a single step. A charging module that has a multi-stage structure inside the coil and that has as many parts as possible in a single-stage structure to reduce the L value, reduce AC resistance, and improve transmission efficiency. Can do.

According to a third aspect of the invention, a plurality of stages in superimposed wound portion of the planar coil portion, a non-contact charging according to claim 1, wherein the area is smaller than the portion wound in one step In the module, as many portions of the coil as possible have a one-stage structure, the AC resistance can be kept low, and the transmission efficiency can be improved.

The invention according to claim 4 includes a planar coil portion in which a plurality of conductive wires are wound in a spiral shape, and a magnetic sheet provided so as to face a coil surface of the planar coil portion, The conducting wires are connected to each other at both ends thereof, and the planar coil portion is wound with the inner portion wound in a plurality of steps, and the outer portion is wound with a number of steps smaller than the number of steps wound on the inner portion. A non-contact charging module characterized in that the non-contact charging module can be reduced in size and thickness in a state in which the cross-sectional area of the planar coil portion is sufficiently secured and the power transmission efficiency is improved. it can.

Invention of Claim 5 used the planar coil part with which the non-contact charge module as described in any one of Claims 1-4 was equipped for at least any one of the coil for power transmission or the coil for power reception. The non-contact charging device can be reduced in size and thickness in a state where the cross-sectional area of the planar coil portion is sufficiently secured and the power transmission efficiency is improved.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an assembly diagram of a contactless charging module according to an embodiment of the present invention, FIG. 2 is a conceptual diagram of the contactless charging module according to an embodiment of the present invention, (a) is a top view, and (b) is a diagram. 2A are cross-sectional views viewed from the A direction, and FIGS. 2C and 2D are cross-sectional views viewed from the B direction of FIG. FIG. 3 is a conceptual diagram showing how to wind the coil of the non-contact charging module in the embodiment of the present invention, FIG. 4 is a conceptual diagram of the magnetic sheet of the non-contact charging module in the embodiment of the present invention, (a) FIG. 5B is a top view, FIG. 4B is a cross-sectional view seen from the A direction in FIG. 4A, and FIGS. 5C and 5D are cross-sectional views seen from the B direction in FIG. FIG. 5 is a top view of the magnetic sheet of the non-contact charging module in the embodiment of the present invention.

  The contactless charging module 1 of the present invention includes a planar coil portion 2 in which a plurality of conductive wires are wound in a spiral shape, and a magnetic sheet 3 provided so as to face the surface of the coil 21 of the planar coil portion 2. The plurality of conductive wires are connected to each other at both ends thereof, and the planar coil portion 2 is wound with a part thereof being stacked in a plurality of stages and the other part being wound in a single stage. It is a non-contact charging module.

  As shown in FIGS. 1 and 2, the planar coil unit 2 includes a coil 21 in which a conductor is wound in a radial direction so as to draw a vortex on the surface, and terminals 22 and 23 provided at both ends of the coil 21. . The coil 21 is obtained by winding two conductive wires in parallel on a plane, and a surface formed by the coil is called a coil surface. Further, since the two conductors are electrically connected by solder or the like at the terminals 22 and 23, the two conductors become one thick conductor. That is, the two conducting wires are planar and are wound around the same center, and one conducting wire is sandwiched between the other conducting wires in the radial direction. Thus, even if it is the same cross-sectional area, thickness can be restrained by electrically joining two conducting wires in the terminal 22 and 23 part, and making it function like one conducting wire. That is, for example, the cross-sectional area of a conducting wire having a diameter of 0.25 mm can be obtained by preparing two conducting wires having a diameter of 0.18 mm. Therefore, if the diameter of one conducting wire is 0.25 mm, the thickness of one turn of the coil 21 is 0.25 mm, the radial width of the coil 21 is 0.25 mm, but the conducting wire 2 having a diameter of 0.18 mm. In the case of a book, the thickness of one turn of the coil 21 is 0.18 mm, and the width in the radial direction is 0.36 mm. In addition, the thickness direction is a stacking direction of the planar coil portion 2 and the magnetic sheet 3.

  In addition, the coil 21 is overlapped in two stages in the thickness direction only at a part on the center side, and the remaining outer part is one stage. At this time, a part of the coil 21 on the center side is wound so as to overlap as shown in FIG. 3 (a) or FIG. 3 (b). As shown in FIG. 3A, the upper conductor and the lower conductor are wound so as to leave a space between each other, thereby reducing the stray capacitance between the upper conductor and the lower conductor, and the coil 21. The AC resistance can be kept small.

  Further, as shown in FIG. 3B, the upper conductor and the lower conductor are wound so as to close each other, whereby the thickness of the coil 21 can be suppressed.

  Further, in the present embodiment as shown in FIG. 3, the cross-sectional area is a conducting wire having a circular shape, but a conducting wire having a square shape or the like may be used. However, in the case of a circular conductor compared with a rectangular conductor, a gap is formed between adjacent conductors, so that the stray capacitance between the conductors is reduced, and the AC resistance of the coil 21 is reduced. Can do.

  In addition, the coil 21 is wound in one stage rather than being wound in two stages in the thickness direction, so that the alternating current resistance of the coil 21 is lowered and transmission efficiency can be increased. This is because when a conducting wire is wound in two stages, stray capacitance is generated between the upper conducting wire and the lower conducting wire. Therefore, it is better to wind as many portions as possible in one stage rather than winding the entire coil 21 in two stages. Moreover, it can reduce in thickness as the non-contact charge module 1 by winding in 1 step | paragraph. In addition, the loss in the coil 21 is prevented because the alternating current resistance of the coil 21 is low, and the power transmission efficiency of the contactless charging module 1 depending on the L value can be improved by improving the L value.

  In this embodiment, the inner diameter x inside the coil 21 shown in FIG. 1 is 10 mm to 20 mm, and the outer diameter is about 30 mm. As the inner diameter x is smaller, the number of turns of the coil 21 can be increased in the contactless charging module 1 of the same size, and the L value can be improved.

  In addition, although the terminals 22 and 23 may be close to each other or may be arranged apart from each other, the non-contact charging module 1 is easier to mount if they are arranged apart.

  The magnetic sheet 3 is provided in order to improve the power transmission efficiency of the non-contact charging using the electromagnetic induction action. As shown in FIG. 4, the flat part 31, the central convex part 32, the concave part 33, Is provided. The recess 33 may be a slit 34. In this embodiment, a Ni—Zn ferrite sheet, a Mn—Zn ferrite sheet, a Mg—Zn ferrite sheet, or the like can be used as the magnetic sheet 3. The ferrite sheet can reduce the AC resistance of the coil 21 as compared with the amorphous metal magnetic sheet. In addition, the center convex part 32 is not necessarily required.

  In this embodiment, the magnetic sheet 3 is about 33 mm × 33 mm. The thicknesses of the flat portion 31, the convex portion 32, and the concave portion 33 are set so that d1 shown in FIG. 4B is 0.2 mm, d2 is 0.2 mm, and d3 is 0.4 mm. As the magnetic sheet 3 is thicker, the power transmission efficiency of the contactless charging module is improved. Therefore, the larger the height d1 of the convex portion 32 is, the higher the transmission efficiency of the contactless charging module 1 is. However, since the thickness of the non-contact charging module 1 increases by an amount corresponding to the convex portion 32 being made larger than the diameter of the conducting wire, the diameter of the conducting wire constituting the coil 21 is made substantially the same. Further, the diameter of the convex portion 32 is substantially the same as the inner diameter of the coil 21. That is, the center of the axis of the coil 21 and the center of the convex part 32 substantially coincide, and the coil 21 is wound around the convex part 32. Further, d2 is also substantially the same as the diameter of the conducting wire constituting the coil 21, and the concave portion 33 is formed only with a minimum depth. This is because the magnetic sheet 3 becomes thinner as the concave portion 33 becomes deeper, so that the transmission efficiency of the non-contact charging module 1 is lowered.

  The concave portion 33 includes a circular portion 33 a formed so as to surround the convex portion 32 and a linear portion 33 b extending from the circular portion 33 a to the end of the magnetic sheet 3. The width of the circular portion 33a is about 1 mm to 2 mm, and the width of the straight portion 33b is about 0.4 mm to 1 mm (the diameter of the conducting wire + about 0.1 mm). The straight portion 33b is substantially perpendicular to the end portion of the magnetic sheet 3, and is formed so as to overlap the tangent line on the outer periphery of the circular portion. By forming the straight portion 33b in this way, the terminals 22 and 23 can be formed without bending the conducting wire. In this case, the length of the straight portion 33b is about 15 mm to 20 mm. Further, as shown in FIG. 5, the straight portion 33b may be formed at a portion where the end of the magnetic sheet 3 and the outer periphery of the circular portion 33a are closest to each other. Thereby, the formation area of the recessed part 33 can be suppressed to the minimum, and the transmission efficiency of the non-contact charge module 1 can be improved. In this case, the length of the straight portion 33b is about 5 mm to 10 mm. In either arrangement, the inner end portion of the straight portion 33b is connected to the circular portion 33a. Moreover, you may make the linear part 33b other arrangement | positioning. That is, it is desirable that the coil 21 has a one-stage structure as much as possible. In that case, all the turns in the radial direction of the coil 21 have a one-stage structure, or a part has a one-stage structure and the other part has a two-stage structure. It is possible to do. Accordingly, one of the terminals 22 and 23 can be pulled out from the outer periphery of the coil 21, but the other must be pulled out from the inside. Accordingly, the portion around which the coil 21 is wound and the portion from the end of winding of the coil 21 to the terminal 22 or 23 always overlap in the thickness direction. Therefore, the straight portion 33b may be provided in the overlapping portion.

  Further, the straight portion 33b may be a recess 33 as shown in FIG. 4C, or may be a slit 34 as shown in FIG. 4D. That is, if it is the recessed part 33, since a through-hole and a slit are not provided in the magnetic sheet 3, it can prevent that a magnetic flux leaks and can improve the electric power transmission efficiency of the non-contact charge module 1. FIG. On the other hand, in the case of the slit 34, the magnetic sheet 3 can be easily formed. When it is the recessed part 33, as shown in FIG.4 (c), it is not limited to the recessed part 33 whose cross-sectional shape becomes a square shape, It may be circular arc shape or roundish.

  Note that the above-described d1, d2, the width of the circular portion 33a, and the like depend on the diameter of the conducting wire, and are not limited to the above values. Moreover, d1 and d2 do not necessarily need to be the same. This is because the coil may be wound in three or more stages in the circular portion 33a.

  FIG. 6 is a diagram illustrating the relationship between the thickness of the ferrite sheet of the contactless charging module and the L value of the coil 21 in the embodiment of the present invention. The thickness of the ferrite sheet referred to here is the sum of d2 and d3 in FIG. 4B, and the protrusion 32 is not relevant. Therefore, in this embodiment, the thickness of the ferrite sheet is 0.6 mm. At this time, the number of turns of the coil 21 is 30 turns, and the inner diameter of the coil 21 is 10 mm. As shown in FIG. 6, the L value of the coil 21 exceeds 34 μH at about 0.6 mm. For the first time, the WPC standard, which is the standard for the non-contact charging module 1, can be satisfied. Moreover, since the whole thickness of the non-contact charging module 1 will increase if it is 0.6 mm or more thick, it is set to 0.6 mm in this embodiment. The optimum value when the thickness is 0.6 mm is because the above-described ferrite sheet is used. When an amorphous metal magnetic sheet is used, the value is different.

  Next, the relationship between the inner diameter of the coil 21 and the L value and the relationship between the number of turns of the coil 21 and the L value will be described. FIG. 7 is a diagram showing the relationship between the inner diameter and the L value of the coil 21 of the contactless charging module in the embodiment of the present invention, and FIG. 8 shows the number of turns of the coil 21 of the contactless charging module in the embodiment of the present invention. It is a figure which shows the relationship with L value. In FIG. 7, the number of turns of the coil 21 is 30 turns, and in FIG. 8, the inner diameter of the coil 21 is 10 mm.

  As the L value of the coil 21 is higher, the transmission efficiency of the contactless charging module 1 is improved, and the L value is required to be about 30 μH in order to satisfy the WPC standard described above. Therefore, as apparent from FIGS. 7 and 8, the coil 21 needs to have at least about 30 turns and the coil 21 has an inner diameter of at least about 10 mm. However, since the thickness and size of the non-contact charging module 1 are regulated by, for example, the size of the battery pack of the mobile phone on which the non-contact charging module 1 is mounted, it is necessary to reduce the size and thickness.

  Accordingly, in the present invention, two conductors are electrically connected at the terminals 22 and 23 so that one conductor having a large diameter is obtained, and the thinning is realized while ensuring the same cross-sectional area of the conductor. To do. In addition, since the width of the coil 21 in the radial direction is larger than that of one conductor by using two conductors, only a part of the innermost part has a two-stage structure. Thereby, even if it is the magnetic sheet 3 of a limited magnitude | size, the winding number of the coil 21 can fully be ensured. Moreover, since the area of the recess 33 can be minimized by setting the two-stage structure to the inside, the power transmission efficiency of the non-contact charging module 1 can be maintained. Further, by setting the two-stage structure as an inner side and as many portions of the coil 21 as possible as a single-stage structure, the AC resistance can be suppressed low and the L value can be increased. Further, by providing an annular recess 33 for thinning the magnetic sheet 3 in a portion of the magnetic sheet that faces the portion of the planar coil portion 2 that is wound on the plurality of steps of the planar coil portion 2, a plurality of steps of the coil are provided. It is possible to offset the difference in thickness between the portion overlapped with the one-step portion and the one-step portion, thereby further reducing the thickness.

  Further, as shown in FIG. 5, convex portions 32 a may be formed at the four corners of the magnetic sheet 3 and in the region where the coil 21 on the flat portion 31 is not disposed. That is, nothing is placed on the magnetic sheet 3 at the four corners of the magnetic sheet 3 and outside the outer periphery of the coil 2 on the flat portion 31. Therefore, the thickness of the magnetic sheet 3 can be increased by forming the convex portion 32a there, and the power transmission efficiency of the non-contact charging module can be improved. The thickness of the convex portion 32a is preferably as thick as possible, but for the purpose of thinning, the thickness of the conductive wire is almost the same as that of the central convex portion 32.

  Further, the coil 21 is not limited to being annularly wound, and may be wound in a square shape or a polygonal shape. Furthermore, the inner side has a three-stage structure, the outer side has a two-stage structure, the inner side is wound in multiple stages, and the outer side is wound with a number of stages smaller than the number of stages wound on the inner side. An effect can be obtained.

  Next, the non-contact charging device provided with the non-contact charging module 1 of the present invention will be described. The non-contact power transmission device includes a charger including a power transmission coil and a magnetic sheet, and a main device including a power receiving coil and a magnetic sheet. The main device is an electronic device such as a mobile phone. The circuit on the charger side includes a rectifying / smoothing circuit unit, a voltage conversion circuit unit, an oscillation circuit unit, a display circuit unit, a control circuit unit, and the power transmission coil. The circuit on the main device side includes the power receiving coil, a rectifier circuit unit, a control circuit unit, and a load L mainly composed of a secondary battery.

  The power transmission from the charger to the main device is performed using an electromagnetic induction action between the power transmission coil of the charger on the primary side and the power receiving coil of the main device on the secondary side.

  Since the non-contact charging device of the present embodiment includes the non-contact charging module described above, the non-contact charging device is reduced in size in a state where the cross-sectional area of the planar coil portion is sufficiently secured to improve the power transmission efficiency. And thinning.

  According to the contactless charging module of the present invention, the contactless charging module can be reduced in size and thickness in a state in which the cross-sectional area of the planar coil portion is sufficiently secured and the power transmission efficiency is improved. It is useful for electronic devices that are portable, and is useful as a non-contact charging module for various electronic devices such as portable terminals such as mobile phones, portable audios, portable computers, digital cameras, and video cameras.

DESCRIPTION OF SYMBOLS 1 Non-contact charge module 2 Planar coil part 21 Coil 22,23 Terminal 3 Magnetic sheet 31 Flat part 32 Convex part 33 Concave part 34 Slit

Claims (5)

A planar coil portion in which a plurality of conductive wires are wound in a spiral shape;
The plane is placed a coil surface of the coil portion, and a magnetic sheet provided so as to face the coil surface of the flat coil portion,
The plurality of conductive wires are connected to each other at both ends thereof,
The planar coil portion is turned overlapping portions in a plurality of stages winding, and winding a portion of the other in one step,
The magnetic sheet is provided with an annular recess or slit that thins the magnetic sheet in a portion facing a portion of the planar coil portion that is wound in layers.
The contactless charging module , wherein the plurality of conductive wires are housed in the annular recess . 2. The contactless charging module according to claim 1, wherein the planar coil portion is wound in a plurality of stages on the inner side, and the remaining outer side is wound in one step. 2. The contactless charging module according to claim 1, wherein a portion of the planar coil portion wound in an overlapping manner is smaller in area than a portion wound in one step. A planar coil portion in which a plurality of conductive wires are wound in a spiral shape;
The plane is placed a coil surface of the coil portion, and a magnetic sheet provided so as to face the coil surface of the flat coil portion,
The plurality of conductive wires are connected to each other at both ends thereof,
The planar coil part is wound with its inner part being stacked in multiple stages, and the remaining outer part is wound with a number of stages less than the number of stages wound with the inner part,
The magnetic sheet includes an annular recess that thins the magnetic sheet in a portion facing a portion of the planar coil portion that is wound in a plurality of stages.
The contactless charging module , wherein the plurality of conductive wires are housed in the annular recess . Non-contact charging apparatus characterized by comprising a non-contact charging module according to any one of claims 1-4.

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