WO2012039045A1

WO2012039045A1 - Contactless power transmission coil

Info

Publication number: WO2012039045A1
Application number: PCT/JP2010/066455
Authority: WO
Inventors: 栄一漆畑; 圭介岩脇
Original assignee: パイオニア株式会社
Priority date: 2010-09-22
Filing date: 2010-09-22
Publication date: 2012-03-29
Also published as: JPWO2012039045A1; JP5216938B2

Abstract

A contactless power transmission coil (300) comprises a substrate (301), and is composed by having a conductor (110), which is formed on a surface (301a) of the substrate (301) and comprises a metallic pattern, wound around, in order to prevent deviation of current at a portion of the conductor positioned at the innermost circumference of the coil, and prevent local heating to make the coil more efficient. At least the portion of the conductor (110) positioned at the innermost circumference is divided into a plurality of strip-formed conductors (110a-110c), and each of the plurality of strip-formed conductors (110a-110c) are arranged in exchanging manner so as to be positioned at the innermost circumference at different places in the circumference direction.

Description

Non-contact power transmission coil

This invention relates to a non-contact power transmission coil for transmitting power in a non-contact manner by electromagnetic induction. However, utilization of this invention is not restricted to the coil for non-contact electric power transmission mentioned above.

FIG. 8 is a plan view showing a coil used in a conventional non-contact power feeding device. The non-contact power feeding device 2000 shown in FIG. 8 is a non-contact power feeding device that transmits electric power by mutual induction action of electromagnetic induction by arranging a primary coil and a secondary coil to face each other even if they are non-contact. (For example, refer to Patent Document 1 below.) This non-contact power supply apparatus 2000 has a structure in which a coil 2001 made of a wire material including a plurality of parallel conductive wires as a set is wound on the back plate 2015 in a flat manner on the same surface, and the coil 2001 is covered with a mold resin 2017. It is fixed. A foam material is mixed in the mold resin 2017. Both ends of the coil 2001 are bent out toward the outside at substantially the same portion and supplied with electric power.

The opposing coil has the same configuration as that shown in FIG. 8, and this non-contact power feeding device is used for charging a battery of an electric vehicle, for example. From 2001, electric power is supplied to a secondary (power receiving side) coil (not shown) in a non-contact manner.

JP 2008-87733 A

In FIG. 8, litz wire is used to reduce high-frequency AC resistance, but the manufacturing becomes complicated by winding or the like. There was also a problem that it was heavy in weight. We propose a highly efficient coil that simplifies the manufacturing process, reduces the weight of the product, and makes it thinner. Although the coil by a metal pattern is effective with respect to the skin effect, the following problems have arisen in the conventional non-contact power feeding device.

1. Influence of proximity effect The magnetic flux becomes stronger as it goes inside the coil. Therefore, the influence of the proximity effect is large, and the current deviation in the conductor increases as the inside of the coil is increased.
2. Influence of the crossing point on the coil In order to lead out the end of the conductor (primary coil) 2001 wound to the inside, a crossing point A orthogonal to the coil 2001 is formed. Heat is generated.

1. Influence of Proximity Effect FIG. 9-1 is an explanatory diagram for explaining the proximity effect when there are two conductors. It is assumed that two

flat conductors

2201 and 2202 are arranged close to each other in parallel and the same current flows in the same direction. In this case, as shown in the lower current density characteristic graph, the currents on the

conductors

2201 and 2202 flow biased outwardly away from each other.

FIG. 9-2 is an explanatory diagram for explaining the proximity effect when there are two conductors. It is assumed that two

conductors

2201 and 2202 are arranged close to each other in parallel and the same current flows in the opposite direction. In this case, as shown in the lower current density characteristic graph, the currents on the

conductors

2201 and 2202 flow in a biased manner toward the inside.

FIG. 9-3 is an explanatory diagram for explaining the proximity effect when there are three conductors. It is assumed that three

conductors

2201, 2202, 2203 are arranged close to each other in parallel and the same current flows in the same direction. In this case, as shown in the lower current density characteristic graph, the currents on the

outer conductors

2201 and 2202 flow biased outwardly away from each other. The central conductor 2203 is less biased due to the influence of the

conductors

2201 and 2202 on both sides, but it is difficult for current to flow through the entire conductor.

FIG. 9-4 is a plan view showing a current direction on the coil. In the

wound conductors

2201, 2202, 2203, the direction of the current is reversed on the left side and the right side as viewed along the line cc in the figure. As a result, as shown in the current density graph, the current flows in the outer conductor 2201 while being biased outward as in FIG. 9C. The inner conductor 2202 is further influenced by the conductor on the opposite side of the coil (the right side is the left side) in addition to the influence of the current in the same direction located on the outer side, so that the inner bias is further increased.

In the current density characteristics, the inner conductor 2202 has a higher current bias toward the inner side as shown in FIG. 9-2 and the effect of FIG. 9-3 (location C). Note that the influence of the conductor on the opposite side of the coil (the right side is the left side) is slightly mitigated with respect to the central conductor 2203, but the current bias toward the inside is still higher than that in FIG. 9-3.

As described above, the wound coil has a magnetic flux that becomes stronger as it goes inside the coil due to the proximity effect, and a current bias within the conductor becomes larger as it goes inside the coil. Therefore, when the coil is formed with a metal pattern, the effect is thin even if the pattern width is widened for the purpose of reducing the resistance value.

2. FIG. 10 is a plan view showing another conventional coil. FIG. 10 shows a coil 2301 used for explaining the temperature distribution, which differs from the coil 2001 shown in FIG. 8 in that the conductor is formed of a metal pattern. Similarly to the coil 2001 in FIG. 8, the end 2301E of the coil 2301 wound to the inside is led out to the external electrode 2303 via the conductor 2302, and for this derivation, the coil 2301 is wound. A crossing point D where the portion of the conductor 2302 is orthogonal to the direction is formed. Since this intersection D is a portion where the current is most biased due to the proximity effect, it is affected by a very strong magnetic flux, eddy current is generated, and heat loss is generated.

FIG. 11 is a diagram showing a temperature distribution when the coil shown in FIG. 10 is driven. The figure shows that the temperature becomes higher as it becomes whiter, and there are places where the temperature is as high as 86 ° C. at the maximum while it is as low as 31 ° C. In particular, it is shown that the temperature increases toward the inside of the coil 2301. A graph of temperature distribution along the line ee in the figure is shown in the lower part. As can be seen from this graph, the coil 2301 wound around three turns has the lowest temperature at the outermost periphery, the temperature increases as it goes inward, and the peak value p at which the temperature becomes highest is generated at the innermost periphery. ing. Further, the temperature at the intersection D on the coil 2301 is high. Therefore, the highest temperature is inside the coil 2301 and at the intersection d. As described above, in the conventional coil, high heat is generated at the intersection of the conductors, and there is a problem that efficiency is lowered due to the heat.

As described above, when a conductor is formed of a wire, the conventional coil is complicated to manufacture by winding or deriving the conductor. In addition, the wire is a copper wire and has a problem that it is heavy in weight. In addition, if there is a winding intersection on the coil, heat is generated in this portion, and the efficiency is lowered. Furthermore, due to the influence of the proximity effect, the current deviation in the conductor increases as the coil is located inside, and the influence is particularly great when formed with a metal pattern. As described above, the conventional coil has various problems.

In order to solve the above-described problems and achieve the object, a non-contact power transmission coil according to the invention of claim 1 includes a support member and a conductor formed of a metal pattern formed on one surface of the support member. A first coil that is wound, wherein the first coil has at least the innermost conductor divided into a plurality of conductors, and each of the plurality of conductors is different in the circumferential direction. It is replaced and arranged so as to be located at the innermost circumference at a position.

FIG. 1 is a plan view showing a main part of an embodiment of a contactless power transmission coil. FIG. 2 is a block diagram showing a charging system to which a contactless power transmission coil is applied. FIG. 3 is a plan view showing the configuration of the first embodiment of the non-contact power transmission coil. FIG. 4 is a diagram illustrating temperature distribution characteristics of the non-contact power transmission coil according to the first embodiment. FIG. 5-1 is a plan view (surface side) showing the configuration of the second embodiment of the non-contact power transmission coil. FIG. 5-2 is a plan view (on the back side) showing the configuration of the second embodiment of the non-contact power transmission coil. FIG. 6 is a plan view showing the configuration of a third embodiment of the non-contact power transmission coil. FIG. 7 is a diagram for explaining a state of current bias according to the third embodiment. FIG. 8 is a plan view showing a coil used in a conventional non-contact power feeding apparatus. FIG. 9A is an explanatory diagram (part 1) for explaining the proximity effect when there are two conductors. FIG. 9B is an explanatory diagram (part 2) for explaining the proximity effect in the case of two conductors. FIG. 9C is an explanatory diagram for explaining the proximity effect when there are three conductors. FIG. 9-4 is a plan view showing a current direction on the coil. FIG. 10 is a plan view showing another conventional coil. FIG. 11 is a diagram showing a temperature distribution when the coil shown in FIG. 10 is driven.

DETAILED DESCRIPTION Exemplary embodiments of a contactless power transmission coil according to the present invention will be described below in detail with reference to the accompanying drawings.

(Embodiment)
(Basic configuration of non-contact power transmission coil-Example of inner circumference divided into three)
First, the configuration of the contactless power transmission coil according to the present embodiment will be described. FIG. 1 is a plan view showing a main part of an embodiment of a contactless power transmission coil. The non-contact power transmission coil (coil) 100 shown in FIG. 1 is a partial description of only the conductor 110 located at the innermost circumference among the conductors 110 of the wound coil.

As shown in the drawing, the wound conductor 110 is formed by a metal pattern on a substrate (not shown). One conductor 110 has a width L1, whereas the innermost conductor 110 located inside the central region 120 has a plurality of strips from the predetermined starting point 110A (example shown in the figure). In this case, the conductors (strip conductors) 110a to 110c are divided into three parts. One electrode is formed at the end 110E, which is the end point of the conductor 110, and all of the divided strip conductors 110a to 110c are connected to the end 110E. In the drawing, the entire width L2 of the strip conductors 110a to 110c is shown wider than the width L1 of the conductor 110 because there is a gap between the strip conductors 110a to 110c. And L2 may be matched. That is, when the conductor 110 has the width L1, each of the three strip conductors 110a to 110c may be slightly wider or narrower with a width of about 1/3 of the width L1 of the conductor 110 as a reference.

The strip conductors 110a to 110c divided into three are replaced with the strip conductors 110a to 110c located on the innermost side (close to each side) with respect to the sides 120a to 120d of the square central region 120. It is arranged as follows. The winding order of the coil 100 will be described. The conductor 110 is arranged along the first side 120a, and the divided

strip conductors

110c, 110b, and 110a are arranged in the order close to the side 120b. Yes. In the side 120c, the

strip conductors

110a, 110c, and 110b are arranged in the order as viewed in the closest order. In the side 120d, the

strip conductors

110b, 110a, and 110c are arranged in this order as viewed in the closest order.

Here, 121 and 122 are connection conductors, specifically, jumper wires or through holes and wiring patterns formed in the substrate on which the conductor 110 is formed, and other strip conductors 110a in an insulated state. It crosses ~ 110c. Similarly, the end portion 110E of the conductor 110 is taken out to the outside through a similar connecting conductor. In this way, the wiring that straddles the conductor 110 is made, but it is not in the form of straddling the conductor 110, but is an electrically insulated jumper line, or a wiring pattern (metal pattern) formed inside or on the back of the substrate. Therefore, the heat generation that occurs in the conventional intersection is not generated.

As described above, among the strip conductors 110a to 110c divided into three, the one located at the innermost periphery is replaced at each side 120b to 120d. That is, one of the strip conductors 110a to 110c divided into three is located on the innermost periphery along any one of the sides 120b to 120d.

According to the above configuration, the strip conductors 110a to 110c located on the innermost circumference of the wound coil conductor 110 are divided into a plurality of pieces, and any of the divided strip conductors 110a to 110c is located on the innermost circumference. Will do. Since the arrangement is changed so that the divided strip conductors 110a to 110c are alternately located at the innermost circumference, the influence of the proximity effect that the current deviation in the conductor becomes larger as it goes inside the coil is suppressed. Therefore, it is possible to suppress loss due to heat generation at the innermost part of the wound conductor 110. In particular, the occurrence of a high heat generation peak at the innermost position of the conductor 110 can be suppressed.

The coil 100 having the above configuration uses a metal pattern for a coil through which a high-frequency current flows, and can be configured to be lightweight and easily formed on a substrate by etching.

In the above embodiment, the number of divisions of the strip conductors is 3, but the number is not limited to this, and a plurality (2 to n) can be used. For example, when the central region is a quadrangle and the number of sides is 4, the number of strip conductors can be set to 4, and the divided strip conductors can be replaced so as to be close to each innermost side. If the central region is a pentagon, the number of strip conductors can be set to five.

Further, if the central region is circular, the number of strip conductors is divided into a plurality (2 to n), and the divided strip conductors are replaced at an angle obtained by dividing the entire circumference by a predetermined angle unit so as to be close to the central region. Can be placed. The predetermined angle unit may be an angle divided by the number of divisions. For example, if the number of divisions of the strip conductor is 3, the predetermined angle is 120 degrees. As described above, various shapes can be considered for the substrate and the conductor pattern, and the strip conductor having the above-described configuration can be applied to any of the shapes.

(Charge system configuration)
Next, the non-contact power transmission coil 100 described above is applied to a charging system 200 that charges an electric vehicle (EV) or a hybrid vehicle (HV). FIG. 2 is a block diagram showing a charging system 200 to which the non-contact power transmission coil 100 is applied. The charging system 200 includes a charging device 201 and a power receiving device 210 provided on the automobile side.

The charging device 201 and the power receiving device 210 are each provided with a non-contact power transmission coil 100, and the power transmitted from the charging device 201 passes through the pair of non-contact power transmission coils 100 of the automobile side power receiving device 210. The battery (secondary battery) 213 is charged.

The charging device 201 uses an AC power source such as a commercial power source or a household power source, or a DC power source supplied from the outside such as solar power generation as a power supply source. The supplied power is supplied to the coil 100 described above via a power factor correction circuit (PFC: Power Factor Correction) 202, a DC converter 203, and an inverter 204. The inverter 204 performs DC-AC conversion and frequency / PWM control. Reference numeral 205 denotes a resonance capacitor of the coil 100. Thereby, a specific voltage and frequency are applied to the coil 100, and the coil 100 generates an electromagnetic field in the power receiving device 210 on the opposite automobile side.

The coil 100 of the power receiving apparatus 210 receives the electromagnetic field generated by the coil 100 of the charging apparatus 201 and converts it into direct current by the resonance capacitor 211 and the rectifier / control circuit 212, and then charges the secondary battery 213 of the automobile.

Further, according to the charging system 200 using the coil 100 having the above-described configuration, the loss in the coil 100 portion can be reduced, so that a highly efficient charging system can be obtained.

Example 1
FIG. 3 is a plan view showing the configuration of the first embodiment of the non-contact power transmission coil. In FIG. 3, a non-contact power transmission coil (coil) 300 is configured by winding a conductor 110 on a surface 301a which is one surface of a substrate 301 which is a support member. The configuration shown in FIG. 1 described above is a part of the configuration shown in FIG. 3, and the same components are denoted by the reference numerals shown in FIG.

The substrate 301 shown in FIG. 3 is formed in a substantially rectangular shape with the corner portions inclined, and the coil 300 is wound in a spiral shape in one direction from the outer periphery to the inner periphery of the substrate 301. It consists of a metal pattern. As the substrate 301, a base material such as paper phenol, paper epoxy, glass composite, or glass epoxy is used. A rectangular central region 120 in which no coil is disposed is formed at the central portion of the substrate 301.

The conductor 110 has a substantially constant width and is wound in three turns in the example shown in FIG. 3, and the innermost strip conductors 110a to 110c are close to the sides 120b to 120d of the central region 120. The strip conductors 110a to 110c are arranged so as to be interchanged.

Reference numerals

121 and 122 denote connection conductors, which are provided to change the arrangement of the strip conductors 110a to 110c. 110S and 110E are electrodes, respectively, connected to a connection conductor (not shown) for supplying operating power, and are led out to the outside.

Table 1 shows AC resistance by frequency in Example 1. As shown in this table, the AC resistance can be reduced at any frequency according to the configuration in which the strip conductors 110a to 110c in Example 1 are provided (three divisions + with replacement). For example, when the driving frequency of the coil 300 is 1 kHz, the reduction rate of Example 1 was 56% compared to the case where the strip conductor was simply formed in three parts and the arrangement was not changed.

Thus, according to Example 1, it is shown that by replacing the arrangement of the strip conductors 110a to 110c, the AC resistance can be reduced to 56% compared to the case where the replacement is not performed, and the current bias can be eliminated. Has been. In addition, when the drive frequency is 10 kHz, it can be reduced to 66% compared to the case where the replacement is not performed, and when the drive frequency is 100 kHz, it can be reduced to 76%. In either case, the AC resistance can be suppressed, and the efficiency can be improved.

FIG. 4 is a diagram showing the temperature distribution characteristics of the non-contact power transmission coil of Example 1. FIG. As shown in the drawing, the temperature is about 30 ° C. at the maximum, and the temperature can be kept lower than in the past. The temperature distribution diagram taken along the line II in the upper diagram is shown in the lower diagram. In the figure below, the horizontal axis represents position, and the vertical axis represents temperature. As shown in the drawing, among the conductors 110 having three turns (a, b, c) as a whole, the portions (c1, c2, c3) of the strip conductors 110a to 110c located at the innermost periphery (c) are strips. Since the conductors 110a to 110c are replaced and arranged, the temperature is generally higher than the other parts a and b on the outer periphery, but the peak of the high temperature that protrudes most at the temperature of the inner periphery c3 does not appear. It is averaged.

(Example 2)
FIGS. 5A and 5B are plan views showing the configuration of the second embodiment of the non-contact power transmission coil. In the second embodiment, the coil 300 described in the first embodiment is formed on both surfaces of the substrate 301. 5A shows the first coil 500a formed on the front surface 301a of the substrate 301, and FIG. 5-2 shows the second coil 500b formed on the back surface 301b of the substrate 301. The basic configuration of the first coil 500a is the same as that of the coil 300 shown in the first embodiment (however, the winding direction is the a direction, which is opposite to FIG. 3).

FIG. 5-2 is a perspective view seen from the front surface 301 a of the substrate 301. A first coil 500a is provided on the front surface 301a of the substrate 301 overlapping with FIG. 5-1, and a second coil 500b is provided on the back surface 301b. The terminal end of the first coil 500a and the starting end of the second coil 500b are electrically connected. At this time, the winding direction a at the end of the first coil 500a and the winding direction a at the start of the second coil 500b are made to coincide with each other.

The first coil 500 a and the second coil 500 b are provided with strip conductors 110 a to 110 c that are divided into three at the innermost peripheral portion of the conductor 110. The strip conductors 110a to 110c on the front surface 301a of the substrate 301 are electrically connected to the strip conductors 110a to 110c on the back surface 301b of the substrate 301 through the through

holes

520, 521, and 522.

Reference numerals

511 and 512 denote electrodes of the second embodiment, and a pair of a starting end of the first coil 500a and a terminal end of the second coil 500b located on the front and back of the substrate 301 through the through

holes

531 and 532, respectively. It is formed as an electrode.

Here, for the strip conductors 110a to 110c provided on the second coil 500b side, the arrangement of the strip conductors 110a to 110c of the first coil 500a formed on the surface 301a of the substrate 301 is changed. It has the function of a connecting conductor.

The replacement of the arrangement of the strip conductors 110a will be described. For the strip conductors 110a to 110c on the first coil 500a side, the arrangement of the strip conductors located on the innermost circumference is A, the arrangement at the center is B, and the arrangement on the outermost circumference is C for convenience. First, the replacement of the arrangement of the strip conductors 110a located at the division starting point 110A (side 120b) of the first coil 500a on the surface 301a side of the substrate 301 will be traced.

The strip conductor 110a is first positioned at the outermost periphery C at the position of the side 120b. Next, the strip conductor 110a is connected to the connection conductor 541 formed on the back surface 301b of the substrate 301 through the through hole 520. Has been. As shown in FIG. 5B, the connection conductor 541 is formed in a pattern so as to be located at the outermost periphery C at the position of the side 120b but at the center B at the position of the side 120c. Thereby, the strip conductor 110a is changed to the position of the center B at the position of the side 120c of the surface 301a of the substrate 301. Thereafter, the strip conductor 110 a is connected to the connection conductor 542 formed on the back surface 301 b of the substrate 301 through the through hole 521. As shown in FIG. 5B, the connection conductor 542 is positioned at the center B at the position of the side 120c, but is patterned so as to be positioned at the innermost periphery A at the position of the side 120d. Thereby, the strip conductor 110a is changed to the position of the inner periphery A at the position of the side 120d of the surface 301a of the substrate 301. As described above, the arrangement of the strip conductors 110a is changed in the order of the outer periphery C → the center B → the inner periphery A.

Similarly, the arrangement of the strip conductor 110b is changed in the order of the center B → the through hole 520 → the connecting conductor 551 → the inner periphery A → the outer periphery C. Further, the strip conductor 110c is arranged in the order of inner circumference A → outer circumference C → through hole 521 → connecting conductor 561 → center B. In the above configuration, the replacement of the arrangement is not necessarily limited to using only the connection conductor provided on the back surface 301b of the substrate 301 using the through

holes

520, 521, and 522. The arrangement of the strip conductors 110a to 110c provided on the surface 301a side of the substrate 301 can be changed. In the example shown in FIG. 5A, the strip conductor 110c located on the inner circumference A of the side 120b is led to the position of the outer circumference C at the side 120c. Similarly, the strip conductor 110b located on the inner periphery A of the side 120c is led to the position of the outer periphery C at the side 120d. In this way, the arrangement of the strip conductors 110a to 110c is changed on the front surface 301a and the back surface 301b of the substrate 301, respectively.

According to the second embodiment described above, as in the first embodiment, by exchanging the arrangement of the strip conductors 110a to 110c, the current bias can be eliminated, the AC resistance can be suppressed, and the efficiency can be improved. Further, since the current bias can be eliminated, the bundles are dispersed and the eddy currents at the intersections of the patterns are reduced, so that no protruding high temperature peak occurs. And since the coil is formed in the front and back of the board | substrate 301 compared with Example 1, a winding number can be doubled and an inductance can be correspondingly increased to the value of a square power.

(Example 3)
FIG. 6 is a plan view showing the configuration of a third embodiment of the non-contact power transmission coil. In the non-contact power transmission coil (coil) 600 according to the third embodiment, similarly to the first embodiment described above, the conductor 110 is wound around the surface 301a that is one surface of the substrate 301 that is the support member. Yes. The difference between the third embodiment is that the number of divisions of the conductor (strip conductor) 110 in the innermost circumference is four.

The strip conductors 110a to 110d divided into four are arranged so that the strip conductors 110a to 110d adjacent to the four sides 120a to 120d of the square central region 120 are interchanged. Reference numerals 121 to 123 denote connection conductors, which are provided to change the arrangement of the strip conductors 110a to 110d.

配置 Explain the replacement of the arrangement in detail. In the position of the side 120a, the strip conductor 110a is located on the outermost side, and the

strip conductors

110b, 110c, and 110d are arranged in this order along the inner periphery. At the position of the side 120b, the outermost strip conductor 110a is rearranged to the innermost circumference by the connecting conductor 121, the strip conductor 110b is located on the outermost side, and the

strip conductors

110c, 110d, 110a are arranged in the order of the inner circumference. Is arranged in. At the position of the side 120c, the strip conductor 110b is rearranged to the innermost circumference by the connecting conductor 122, the strip conductor 110c is located on the outermost side, and the

strip conductors

110d, 110a, 110b are arranged in this order along the inner circumference. ing. At the position of the side 120d, the strip conductor 110c is rearranged to the innermost circumference by the connecting conductor 123, the strip conductor 110d is located on the outermost side, and the

strip conductors

110a, 110b, 110c are arranged in this order along the inner circumference. ing.

FIG. 7 is a diagram for explaining a state of current bias according to the third embodiment. As shown in the figure, by dividing the four strip conductors 110a to 110d into four parts and alternately arranging the divided strip conductors 110a to 110d as described above, the current is not biased to a specific strip conductor. It has been found that the current flows with almost the same value (around 25%) in all of the four divided strip conductors 110a to 110d shown in FIGS. In this figure, a configuration (no rearrangement) in which the inner peripheral conductor 110 is divided into four parts is shown for comparison. If the inner circumference of the conductor 110 is simply divided into four parts and the strip conductors 110a to 110d are not rearranged, the current bias is 15% to 40% as shown in the figure. The bias becomes large, and a current value that protrudes most at the inner periphery is generated. As described above, it can be seen that it is effective not only to divide the strip conductors 110a to 110d but also to rearrange them.

According to the above-described third embodiment, the number of strip conductors is set to four, and the four strip-shaped strip conductors are rearranged so as to be located on the inner circumference. In addition, the current bias in the strip conductor located on the inner periphery can be prevented as compared with the configuration of (5).

As a modification of the above-described third embodiment, it is conceivable that coils are formed on the front and back of the substrate 301 as in the second embodiment. As a result, it is possible to prevent the current from being biased by the strip conductors 110a to 110d divided into four, and to obtain an effect of increasing the inductance by doubling the number of turns.

Further, in each of the embodiments described above, the substrate and conductor patterns have been described as an example of a rectangular configuration. However, as described above, the shape may be various shapes such as a circle and a polygon, and can be similarly applied. In the above-described embodiment, the configuration in which the pattern of the conductor 110 gradually decreases from the outside to the inside has been described. However, the present invention is not limited to this. A configuration may be adopted in which conductors having a plurality of different diameters are formed in a concentric pattern on the substrate, and adjacent patterns having different diameters are connected at a certain point.

Further, by using a metal pattern as the conductor 110 on the substrate as in the above embodiment, the weight can be reduced and various inductances can be easily created simply by changing the pattern.

Further, the base material of the substrate 301 may be a tape-like material such as polyimide, and a metal pattern can be formed on these base materials. For example, by configuring the substrate 301 with a tape-shaped base material such as FPC or TCP, the weight can be reduced, and the coil shape can be a three-dimensional structure as well as a flat surface. By forming the substrate 301 three-dimensionally, the direction of the magnetic flux can be three-dimensionally corresponding to this.

100, 300 Non-contact power transmission coil 110 Conductor 110a-110c Strip conductor 120 Central region 120a-

120d Side

121, 122, 123 Connection conductor 200 Charging system 201 Charging device 210 Power receiving device 301 Substrate 301a Front surface

301b Back surface

110E, 110S, 511 , 512 End (electrode)
520, 521, 522, 531, 532 Through

hole

541, 542, 551, 561 Connecting conductor

Claims

A support member;
A first coil formed on one surface of the support member and wound with a conductor made of a metal pattern;
The first coil is arranged so that at least the conductor located at the innermost circumference is divided into a plurality of conductors, and each of the plurality of conductors is located at the innermost circumference at a position different from the center of the circumference. A coil for contactless power transmission, characterized in that
A second coil having a starting end connected to a terminal end of the first coil, wherein a conductor made of a metal pattern is wound on the other surface different from the one surface on the support member; ,
The second coil is arranged so that at least the conductor located at the innermost circumference is divided into a plurality of conductors, and each of the plurality of conductors is located at the innermost circumference at different positions in the circumferential direction. The non-contact power transmission coil according to claim 1.
The contactless power transmission coil according to claim 1, wherein a connection member straddling the conductors is provided between the conductors arranged to be exchanged.
4. The contactless power transmission coil according to claim 3, wherein the connection member is an insulated jumper wire or a metal pattern formed inside or on the other surface of the support member.
The coil for contactless power transmission according to claim 1, wherein the width of the conductor obtained by dividing the conductor into a plurality of parts is about the width obtained by dividing the width of the conductor by the number of divisions.
The contactless power transmission coil according to claim 1, wherein the plurality of conductors are formed to have equal lengths located in the innermost circumference by replacement in the innermost circumference.
The conductor divided into a plurality of the first coil is electrically connected by a through hole at a position where the position of the other conductor of the second coil coincides with the position on the support member. The contactless power transmission coil according to any one of claims 2 to 6, wherein: