JP2012156482A - Reception side non-contact charging module and reception side non-contact charging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reception side non-contact charging module and a reception side non-contact charging apparatus, capable of preventing an adverse effect from a magnet especially against an inner portion of a coil even if a magnet for alignment is used, and improving power transmission efficiency.SOLUTION: The reception side non-contact charging module comprises: a planar coil part formed by winding a conductor spirally; and a magnetic sheet, on which the planar coil part is mounted, which attracts a circular magnet 30 of a transmission side non-contact charging module 41, when the circular magnet is used for aligning the transmission side non-contact charging module 41, wherein a hollow part of the planar coil part is larger than the circular magnet 30 provided in the transmission side non-contact charging module 41.

Description

  The present invention relates to a receiving-side non-contact charging module and a receiving-side non-contact charging device having a planar coil portion and a magnetic sheet.

  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

  In this type of contactless charging module, a magnet may be used to align the primary side contactless charging module and the secondary side contactless charging module. 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), these primary-side non-contact charging module and secondary-side non-contact charging module If you have a magnet for positioning with, it will be affected by the magnet. That is, the portion of the coil that generates the strongest magnetic field is the inner portion. The inner side portions of the coil of the primary side non-contact charging module and the coil of the secondary side non-contact charging module are opposed to each other. Therefore, for example, if a magnet is present between a portion where the magnet is opposed to the inner portion, the magnet obstructs the magnetic field between the inner portions, thereby reducing the power transmission efficiency of the non-contact charging module.

  Therefore, in view of the above problems, the present invention prevents a bad influence from a gnet on the inner portion of the coil, even when using a magnet for alignment, and a receiving side non-contact charging module that improves power transmission efficiency and An object is to provide a non-contact charging device on the receiving side.

  In order to solve the above-described problems, the present invention provides a receiving-side non-contact charging module that receives electric power from a transmitting-side non-contact charging module by electromagnetic induction. In a receiving-side non-contact charging module in which a circular magnet provided in a contact charging module is used and in a case where a circular magnet is not used, a planar coil portion in which a conductive wire is wound in a spiral shape, and the planar coil And a magnetic sheet that attracts the circular magnet of the transmitting side non-contact charging module when a circular magnet is used for alignment with the transmitting side non-contact charging module, and the hollow of the planar coil unit The receiving unit is larger than a circular magnet provided in the transmitting side non-contact charging module It was a non-contact charging module.

  According to the present invention, even when a magnet for alignment is used, a reception-side non-contact charging module and a reception-side non-contact charging device that prevent adverse effects from gnets, particularly on the inner part of the coil, and improve power transmission efficiency. Can be provided.

Assembly drawing of the non-contact charging module in the embodiment of the present invention The conceptual diagram of the non-contact charge module in embodiment of this invention The conceptual diagram of the magnetic sheet of the non-contact charge module in embodiment of this invention The conceptual diagram of the magnetic sheet of the non-contact charge module in embodiment of this invention The figure which shows the L value of the coil by the presence or absence of a magnet and the presence or absence of lamination | stacking in embodiment of this invention The conceptual diagram of the magnetic sheet of the non-contact charge module in embodiment of this invention The figure which shows the relationship between the L value of a coil, and the thickness of a center part when not using a magnet for position alignment in the non-contact charging module of this Embodiment Sectional drawing of the coil and magnet of the non-contact charge module in embodiment of this invention The figure which shows the relationship between the inner diameter of a coil and the L value of a coil

  The invention according to claim 1 is a receiving-side non-contact charging module that receives electric power from the transmitting-side non-contact charging module by electromagnetic induction, and in the alignment with the transmitting-side non-contact charging module, the transmitting-side non-contact charging module In a receiving-side non-contact charging module in which a circular magnet provided in a contact charging module is used and in a case where a circular magnet is not used, a planar coil portion in which a conductive wire is wound in a spiral shape, and the planar coil And a magnetic sheet that attracts the circular magnet of the transmitting side non-contact charging module when a circular magnet is used for alignment with the transmitting side non-contact charging module, and the hollow of the planar coil unit The receiving side is larger than a circular magnet provided in the transmitting side non-contact charging module A contact-side charging module and a contact-side contactless charging module that prevent adverse effects from the magnet, particularly on the inner part of the coil, and improve power transmission efficiency even when a magnet for alignment is used. Equipment can be provided.

  According to a second aspect of the present invention, in the planar coil portion, the area of the circular magnet is 80% to 95% of the area of the hollow portion of the planar coil portion in a plane parallel to the planar coil portion. The receiving-side non-contact charging module according to claim 1, wherein the receiving-side non-contact charging module can sufficiently cope with variations in alignment accuracy, and further, the primary-side non-contact charging module and the secondary-side non-contact charging module. The accuracy of alignment with the contact charging module can be improved. Further, the number of turns of the coil 21 can be ensured.

  A third aspect of the present invention is the receiving side non-contact charging module according to the first aspect, wherein the circular magnet has a diameter of 15.5 mm.

  Invention of Claim 4 receives electric power from the transmission side non-contact charging device provided with the said transmission side non-contact charging module, The receiving side non-contact charging module as described in any one of Claims 1-3 is used. A non-contact charging device on the receiving side characterized by comprising a receiving side that prevents adverse effects from the magnet, particularly on the inner part of the coil, and improves power transmission efficiency, even if a magnet for alignment is used An object is to provide a non-contact charging device.

(Embodiment)
Hereinafter, embodiments of the present invention will be described 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). Fig. 2 is a cross-sectional view seen from the A direction in Fig. 2A, and Fig. 2C and Fig. 3D are cross-sectional views seen from the B direction in Fig. 2A. FIG. 3 is a conceptual diagram of a magnetic sheet of a contactless charging module according to an embodiment of the present invention, (a) is a top view, (b) is a cross-sectional view as viewed from the A direction in FIG. (c) And (d) is sectional drawing seen from the B direction of Fig.3 (a). 4A and 4B are conceptual diagrams of the magnetic sheet of the contactless charging module according to the embodiment of the present invention, where FIG. 4A is a top view and FIG. 4B is a cross-sectional view as viewed from the A direction in FIG. .

  The non-contact charging module 1 of the present invention includes a planar coil portion 2 in which a conductive wire is 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.

  As shown in FIG. 1, the planar coil portion 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 a conductive wire in parallel on a plane, and a surface formed by the coil is called a coil surface. In addition, the thickness direction is a stacking direction of the planar coil portion 2 and the magnetic sheet 3. In the present embodiment, the coil 21 is wound outward from an inner diameter of 20 mm in diameter, and the outer diameter is 30 mm. That is, the coil 21 is wound in a donut shape. The coil 21 may be wound in a circular shape or may be wound in a polygonal shape.

  In addition, since the conducting wires are wound so as to leave a space between each other, the stray capacitance between the upper conducting wire and the lower conducting wire is reduced, and the AC resistance of the coil 21 can be kept small. Moreover, the thickness of the coil 21 can be suppressed by winding so that space may be packed.

  Further, in the present embodiment as shown in FIG. 3, the cross-sectional area is a circular conducting wire, 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.

  Moreover, in this Embodiment, the inner diameter x inside the coil 21 shown in FIG. 1 is 10 mm-20 mm, and an 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 non-contact charging using electromagnetic induction action, and corresponds to the flat portion 31 and the inner diameter of the coil 21 at the center as shown in FIG. The center part 32 to perform and the linear recessed part 33 are provided. In addition, as shown in FIG. 3, the center part 32 does not necessarily need to be convex. The linear recess 33 may be a slit 34, and the linear recess 33 or the slit 34 is not always necessary. However, as shown in FIGS. 2 (c) and 2 (d), by providing the linear recess 33 or slit 34, the conducting wire from the end of winding of the coil 21 to the terminal 23 can be accommodated in the linear recess 33 or slit 34. Can be made thinner. That is, the linear concave portion 33 or the slit 34 is formed so as to be substantially perpendicular to the end portion of the magnetic sheet 3 and to overlap the tangent line on the outer periphery of the central portion 32. By forming the linear recess 33 or the slit 34 in this way, the terminals 22 and 23 can be formed without bending the conducting wire. In this case, the length of the linear recess 33 or the slit 34 is about 15 mm to 20 mm. However, the length of the linear recess 33 or the slit 34 depends on the inner diameter of the coil 21. Further, the linear concave portion 33 or the slit 34 may be formed at a portion where the end of the magnetic sheet 3 and the outer periphery of the central portion 32 are closest. Thereby, the formation area of the linear recessed part 33 or the slit 34 can be suppressed to the minimum, and the transmission efficiency of the non-contact charging module 1 can be improved. In this case, the length of the linear recess 33 or the slit 34 is about 5 mm to 10 mm. In either arrangement, the inner end of the linear recess 33 or the slit 34 is connected to the center 32. Further, the linear recess 33 or the slit 34 may be arranged in another manner. 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 are made into a one-stage structure, or one part is made into a one-stage structure and the other part is made into a two-stage structure. It is possible to do. Therefore, 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. Accordingly, the linear recess 33 or the slit 34 may be provided in the overlapping portion. If it is the linear 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. In the case of the linear concave portion 33, it is not limited to the linear concave portion 33 having a square cross section as shown in FIG. 4, and may be arcuate or rounded.

  In the present 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.

  As shown in FIG. 3, the magnetic sheet 3 has at least a high saturation magnetic flux density material 3a and a high magnetic permeability material 3b laminated. Even when the high saturation magnetic flux density material 3a and the high magnetic permeability material 3b are not laminated, it is preferable to use the high saturation magnetic flux density material 3a having a saturation magnetic flux density of 350 mT or more and a thickness of at least 300 μm.

  In addition, either the high saturation magnetic flux density material 3a or the high magnetic permeability material 3b may be closer to the planar coil portion 2, but as shown in FIG. It is better to be near. By setting it as such a structure, the alternating current resistance of the planar coil part 2 can be reduced. As a result, the power transmission efficiency of the non-contact charging module 1 can be improved.

In the present embodiment, the magnetic sheet 3 is about 33 mm × 33 mm. The thickness d1 of the center part 32 shown in FIG.2 (c) is 0.2 mm. Further, d2 shown in FIG. 3C is the thickness of the magnetic sheet 3, which is 0.6 mm, d3 is 0.15 mm, and d4 is 0.45 mm, the magnetic sheet 3, the high saturation magnetic flux density material 3a, The thickness of each of the high magnetic permeability materials 3b is set. In addition, it is good to make it substantially the same as the diameter of the conducting wire which comprises the coil 21, and to form the linear recessed part 33 only with the minimum depth. This is because the transmission efficiency of the non-contact charging module 1 is lowered because the magnetic sheet 3 in the linear concave portion 33 becomes thinner as the linear concave portion 33 becomes deeper.

  Next, why the magnetic sheet 3 has a multilayer structure will be described.

  In general, the contactless charging module 1 uses a magnet for positioning the primary side contactless charging module (transmitting side contactless charging module) and the secondary side contactless charging module (receiving side contactless charging module). There are cases where it is not and cases where it is not. The non-contact charging module 1 is required to operate stably in either case. The magnet is generally mounted on the primary side non-contact charging module, and the magnet can be aligned by mainly pulling the magnetic sheet 3 of the secondary side non-contact charging module.

  At this time, due to the influence of the magnet, the L value of the coil 21 of the non-contact charging module 1 varies greatly depending on whether the magnet is used for alignment or not. This is because the presence of the magnet obstructs the magnetic flux between the primary side and secondary side non-contact charging modules. Therefore, when there is a magnet, the L value of the coil 21 of the non-contact charging module 1 is greatly reduced. In order to suppress the influence of this magnet, the magnetic sheet 3 includes a high saturation magnetic flux density material 3a. Since the high saturation magnetic flux density material 3a is less likely to be saturated with the magnetic field even if the magnetic field becomes strong, the high saturation magnetic flux density material 3a is hardly affected by the magnet, and can improve the L value of the coil 21 when the magnet is used.

  However, since the high saturation magnetic flux density material 3a generally cannot obtain a high magnetic permeability, when the alignment magnet is not used, the L value of the coil 21 is lower than that of the high magnetic permeability material 3b. Accordingly, the magnetic sheet 3 is configured by laminating the high permeability material 3b on the high saturation magnetic flux density material 3a. That is, since the high magnetic permeability material 3b can strengthen the magnetic field, the L value of the coil 21 can be improved. Thereby, even when there is no magnet, the L value of the coil 21 can be improved by the high magnetic permeability material 3b.

  The high saturation magnetic flux density material 3a is a ferrite sheet, the magnetic permeability is 250 or more, and the saturation magnetic flux density is generally about 340 mT. The thickness is 400 μm to 500 μm, and is about 450 μm in the present embodiment. In the present embodiment, for example, a Mn—Zn-based material is preferable, and a material that realizes high magnetic permeability even when thin is preferable.

  The high magnetic permeability material 3b is a ferrite sheet, the magnetic permeability is 3000 or more, and the saturation magnetic flux density is about 300 mT. The thickness is 100 μm to 200 μm, and in the present embodiment is about 150 μm. If the thickness is about 100 μm to 200 μm, the L value of the coil 21 can be improved. In the present embodiment, for example, a Mn—Zn-based material is suitable, and a magnetic sheet 3 that does not greatly change the L value of the coil 21 even when a magnet is present near the non-contact charging module is preferable.

  Thus, in the laminating direction of the magnetic sheet 3, the high saturation magnetic flux density material 3a is about three times the thickness of the high magnetic permeability material 3b, whereby the L value of the coil 21 can be improved and the thickness is reduced. Can be achieved. That is, in order to achieve the effects of the high saturation magnetic flux density material 3a and the high magnetic permeability material 3b within a limited thickness, it is desirable to stack the layers with the thicknesses as described above. Furthermore, when the thickness of the magnetic sheet 3 is about 600 μm, the L value of the coil 21 can be improved and further reduction in thickness can be achieved.

Note that the high saturation magnetic flux density material 3a may be 500 μm or more, and the high magnetic permeability material 3b may be 200 μm or more, if thinning and miniaturization of the non-contact charging module 1 are not taken into consideration. However, by making the high saturation magnetic flux density material 3a about 450 μm and the high magnetic permeability material 3b about 150 μm, it is possible to obtain the effects of the high saturation magnetic flux density material 3a and the high magnetic permeability material 3b while achieving a reduction in thickness. Can do.

  The magnetic sheet 3 may be laminated with an adhesive sheet after firing the high saturation magnetic flux density material 3a and the high magnetic permeability material 3b, or a molded body of each of the high saturation magnetic flux density material 3a and the high magnetic permeability material 3b. After laminating, it may be baked and laminated.

  Further, the high magnetic permeability material 3b may not be laminated on the entire surface of the high saturation magnetic flux density material 3a. That is, it may be formed only at a portion facing the coil 21 or may be formed in the inner circumference of the coil 21.

  Further, the high magnetic permeability material 3b may be an amorphous magnetic sheet. In this case, the thickness can be set to 80 μm to 100 μm, and can be made thinner than the use of ceramic. However, when an amorphous magnetic sheet is used, eddy current loss occurs, and the AC resistance of the coil 21 increases. On the other hand, when a ceramic magnetic sheet is used, AC resistance can be suppressed and charging efficiency can be increased.

  FIG. 5 is a diagram showing the L value of the coil depending on the presence / absence of a magnet and the presence / absence of lamination in the embodiment of the present invention. At this time, the high saturation magnetic flux density material 3a and the high magnetic permeability material 3b are laminated to compare the magnetic sheet 3 of 600 μm with the magnetic sheet 3 of 600 μm using only the high saturation magnetic flux density material. As shown in FIG. 5, when the magnet is used for alignment, the L value does not change in either case. However, when the magnet is not used for alignment, the magnetic sheet 3 in which the high saturation magnetic flux density material 3a and the high magnetic permeability material 3b are laminated has a larger L value. In general, the contactless charging module 1 is required to have an L value of 15 to 35 μH. That is, when the L value is 35 μH or more, the magnetic field is too strong, the AC resistance increases, and the amount of heat generated in the coil 21 increases. On the other hand, when the L value is 15 μH or less, the magnetic field is too weak to transmit power. However, when the magnet is used for alignment, the L value is very low, so the L value is required to be 8 to 35 μH.

  Next, the thickness of the central part of the magnetic sheet 3 will be described. FIG. 6 is a conceptual diagram of the magnetic sheet of the contactless charging module according to the embodiment of the present invention, and the central portion 32 has a concave shape or a through hole. As shown in FIG. 2, the central portion 32 has a convex shape, thereby improving the magnetic flux density of the coil 21 and improving the transmission efficiency of the contactless charging module 1.

  However, the influence of the magnet can be reduced by providing a hole portion in which the central portion 32 has a concave shape or a through hole. The reason will be described below.

  As described above, the contactless charging module 1 may or may not use a magnet for positioning the primary side contactless charging module and the secondary side contactless charging module. In addition, since the magnets interfere with the magnetic flux between the primary side and secondary side non-contact charging modules, the L value of the coil 21 of the non-contact charging module 1 is greatly reduced when there is a magnet. To do. The coil 21 forms an LC resonance circuit using a capacitor (not shown) in the non-contact charging module 1. At this time, if the L value changes significantly depending on whether the magnet is used for alignment or not, the resonance frequency with the capacitor also changes significantly. Since this resonance frequency is used for power transmission between the primary side non-contact charging module and the secondary side non-contact charging module, if the resonance frequency changes greatly depending on the presence or absence of a magnet, power transmission cannot be performed correctly.

  Accordingly, in order to make the resonance frequency close to when the magnet is used for alignment and when not used, the L value of the coil 21 when the magnet is used for alignment and when not used is set to a close value. It is necessary.

  FIG. 7 is a diagram showing the relationship between the L value of the coil and the thickness of the central portion when the magnet is used for alignment in the non-contact charging module of the present embodiment. The degree of hollowing out indicates that 0% is a flat view without forming the central portion 32 into a concave shape, and 100% indicates that the central portion 32 is a through hole. As shown in FIG. 7, when the magnet is not used, the magnetic field of the coil 21 becomes smaller and the L value decreases as the central portion 32 of the magnetic sheet 3 is made thinner. On the other hand, in the case of using a magnet, the thinner the central portion 32 of the magnetic sheet 3 is, the larger the distance in the stacking direction between the magnetic sheet 3 and the magnet is, so the influence of the magnet is reduced and the magnetic field of the coil 21 is reduced. It becomes larger and the L value rises. And when the center part 32 is formed in the through hole, the L value is closest. That is, by using the central portion 32 as a through hole, the influence of the magnet used for alignment can be minimized.

  Further, since the magnet is aligned with the magnetic sheet 3, the accuracy of alignment is improved when the central portion has a certain thickness. In particular, when the degree of cutout is 60% or more, the alignment accuracy is lowered. Therefore, by setting the degree of hollowing to 40 to 60%, the L value of the coil 21 when the magnet is used for positioning and when not used is made close to the value, and at the same time, the effect of magnet positioning is sufficient. Obtainable. That is, the magnet and the central portion 32 of the magnetic sheet 3 are attracted so that the centers can be aligned with each other. In this embodiment, it is about 50%, and both effects can be obtained most effectively. Further, to leave about half the thickness, after the through hole is formed, the through hole may be filled with a magnetic material to a half depth.

  The magnetic sheet 3 may be formed by laminating a high saturation magnetic flux density material 3a and a high magnetic permeability material 3b. For example, one central portion 32 is formed flat and the other central portion 32 is formed as a through hole. The central portion 32 may be formed in a concave shape as the magnetic sheet 3. The diameter of the recess or the through hole is preferably smaller than the inner diameter of the coil. By making the diameter of the recess or the through hole substantially the same as the inner diameter of the coil (0 to 2 mm smaller than the inner diameter of the coil), the magnetic field in the inner circumference of the coil can be increased.

  Further, by making the diameter of the recess or the through hole smaller than the inner diameter of the coil (2 to 8 mm smaller than the inner diameter of the coil), the outer side of the step can be used for alignment, This can be used to make the L value of the coil 21 close to when the magnet is used for alignment and when it is not used. Moreover, it is good for a recessed part or a through-hole to be larger than the size of a magnet.

  Furthermore, since the shape of the upper surface of the recess or the through hole is the same as the shape of the inner circle of the coil 21, the magnet and the central portion 32 of the magnetic sheet 3 attract each other in a well-balanced manner, and the mutual alignment between the centers is accurate. it can.

  Since all the end portions of the recesses or the through holes are equidistant from the inner diameter of the coil 21, the magnet and the central portion 32 of the magnetic sheet 3 are attracted in a balanced manner, and the mutual alignment between the centers can be performed with higher accuracy.

Next, the relationship between the size of the magnet and the size of the inner diameter of the coil 21 will be described. FIG. 8 is a cross-sectional view of the coil and magnet of the contactless charging module according to the embodiment of the present invention. FIG. 9 is a diagram showing the relationship between the inner diameter of the coil and the L value of the coil.

  The primary side non-contact charging module 41 and the secondary side non-contact charging module 42 face each other. Of the coil 21 wound in a planar shape, the primary side coil 21a and the secondary side coil 21b face each other. Of the coils 21a and 21b, the inner portions 211 and 212 are the portions that generate the strongest magnetic field. The inner portions 211 and 212 are opposed to each other. Therefore, when the magnet 30 exists between the portions where the magnet 30 faces the inner portions 211 and 212 as shown in FIG. 8A, the magnet 30 prevents the magnetic field between the inner portions 211 and 212, and the non-contact charging module. 1 power transmission efficiency will be reduced. However, when the magnet 30 is smaller than the inner circumferential circle of the coils 21a and 21b as shown in FIG. 8B, the magnet 30 is present between the portions facing the inner portions 211 and 212 when aligned. do not do. Therefore, the magnet 30 does not hinder the magnetic field between the inner portions 211 and 212, and the power transmission efficiency of the contactless charging module 1 is not reduced.

  For example, when the magnet 30 is circular, it is as follows. That is, when the outer diameter of the magnet 30 and the inner diameter of the coil 21 are the same, the magnet 30 can be maximized, so the positions of the primary-side non-contact charging module and the secondary-side non-contact charging module. The alignment accuracy can be improved. Further, since the inner diameter of the coil 21 can be minimized, the number of turns of the coil 21 can be increased and the L value can be improved. Further, when the outer diameter of the magnet 30 is smaller than the inner diameter of the coil 21, the magnet 30 may not be present between the portions where the inner portions 211 and 212 face each other even if the alignment accuracy varies. it can. At this time, since the outer diameter of the magnet 30 is 80% to 95% of the inner diameter of the coil 21, it can sufficiently cope with variations in alignment accuracy, and further, the primary side non-contact charging module and the secondary side non-contact. The accuracy of alignment with the charging module can be improved. Further, the number of turns of the coil 21 can be ensured. This means that, in a plane parallel to the planar coil portion 2, the area of the magnet 30 is 80% to 95% of the area of the inner circle of the planar coil portion 2.

  Furthermore, as shown in FIG. 9, when the size of the magnet 30 and the outer diameter of the coil 21 are made constant, if the number of turns of the coil 21 is reduced and the inner diameter of the coil 21 is increased, The impact is reduced. That is, the L value of the coil 21 when the magnet 30 is used for alignment between the primary side non-contact charging module and the secondary side non-contact charging module is close to the value when the magnet 30 is not used. Therefore, the resonance frequency when the magnet 30 is used and when it is not used is very close. At this time, the outer diameter of the coil is unified to 30 mm.

  In the WPC standard, the diameter of the magnet 30 is 15.5 mm, and its strength is about 100 mT. In the present embodiment, the inner diameter of the coil 21 is 20 mm and the outer diameter is 30 mm. Moreover, the outer diameter of the center part 32 made into the concave shape or the through-hole is 18 mm. That is, the distance between the inner diameter end portion of the coil 21 of the planar coil portion 2 and the outer end portion of the magnet 30 is about 4.5 mm. As shown in FIG. 9, by setting the distance to about 4.5 mm, the L value of the coil 21 with and without the magnet 30 can be made closer to 15 μH or more. Further, the distance between the inner diameter end portion of the coil 21 of the planar coil portion 2 and the outer end portion of the magnet 30 is larger than 0 mm and smaller than 6 mm, so that the magnet 30 is used while setting the L value to 15 μH or more. The L value in the case of not using the case can be made closer.

The magnetic sheet 3 may be formed by laminating other magnetic materials. For example, the high saturation magnetic flux density material 3a is composed of two layers, and the high magnetic permeability material 3b is sandwiched between the high saturation magnetic flux density materials 3a, or the high magnetic permeability. The material 3b may be composed of two layers, and the high saturation magnetic flux density material 3a may be sandwiched between the high magnetic permeability materials 3b. That is, at least one layer of high saturation magnetic flux density material 3a and at least one layer of high magnetic permeability material 3b may be provided. As the magnetic sheet 3 is thicker, the power transmission efficiency of the contactless charging module 1 is improved.

  Moreover, you may form a thick part in the four corners of the magnetic sheet 3, and the area | region where the coil 21 on the flat part 31 is not arrange | positioned. 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 a thick portion there, and the power transmission efficiency of the contactless charging module 1 can be improved. The thicker the thicker the better, but it is almost the same as the thickness of the conductor for thinning.

  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 1 described above, the non-contact charging device in a state in which the cross-sectional area of the planar coil portion is sufficiently secured to improve the power transmission efficiency. Can be reduced in size and thickness.

  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 211,212 Inner part 21b Secondary side coil (planar coil part)
22, 23 Terminal 3 Magnetic sheet 3a High saturation flux density material (second layer)
3b High permeability material (first layer)
30 Magnet 31 Flat part 32 Center part 33 Straight concave part 34 Slit 41 Primary side non-contact charging module (transmission side non-contact charging module)
42 Secondary side non-contact charging module (receiving side non-contact charging module)

Claims (4)

A receiving side non-contact charging module that receives electric power from the transmitting side non-contact charging module by electromagnetic induction,
In the case of using the circular magnet provided in the transmission side non-contact charging module and the case of not using the circular magnet in the alignment with the transmission side non-contact charging module, in the receiving side non-contact charging module,
A planar coil portion wound with a conducting wire;
A magnetic sheet that mounts the planar coil portion and attracts the circular magnet of the transmitting side non-contact charging module when using a circular magnet for alignment with the transmitting side non-contact charging module;
A receiving-side non-contact charging module, wherein a hollow portion of the planar coil portion is larger than a circular magnet provided in the transmitting-side non-contact charging module. The planar coil portion is configured such that an area of the circular magnet is 80% to 95% of an area of the hollow portion of the planar coil portion in a plane parallel to the planar coil portion. The receiving side non-contact charging module according to claim 1. The receiving-side non-contact charging module according to claim 1, wherein the diameter of the circular magnet is 15.5 mm. The receiving side comprising the receiving side non-contact charging module according to claim 1, wherein the receiving side receives power from the transmitting side non-contact charging device including the transmitting side non-contact charging module. Non-contact charging equipment.

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