JP5595894B2 - Resonant coil and non-contact power transmission device having the same - Google Patents

Description

  The present invention relates to a resonance coil that transmits power to a counterpart coil or receives power transmitted from the counterpart coil by a resonance phenomenon, and a non-contact power transmission apparatus having the resonance coil.

  In recent years, for example, charging of a secondary battery (hereinafter simply referred to as “battery”) included in an electric vehicle or the like is wireless (non-contact) that does not require physical connection such as plug connection in order to facilitate charging work. ) Is used.

  As such wireless power transmission technology, an electromagnetic induction method using an electromagnetic induction phenomenon, an electromagnetic wave transmission method using an electromagnetic wave, a resonance method using a resonance phenomenon, and the like are known. Among them, the resonance method is a technique for transmitting electric power by supplying AC power to the transmission resonance coil and causing the transmission resonance coil to resonate with the reception resonance coil disposed opposite to the transmission resonance coil via an electromagnetic field. It is possible to transmit large power of several kW between relatively distant places.

  However, when such a resonance-type wireless power transmission technology is applied to a system in which large power of several kW to several tens of kW is transmitted, such as a battery charging system of an electric vehicle, for example, as shown in FIG. When the resonance state is reached, a high voltage is generated at or near the end of the coil wire wound in the tubular shape of the resonance coil, and a dielectric breakdown occurs with a grounded case that accommodates the resonance coil, resulting in a spark. There were problems such as the occurrence of discharge. And the technique which solves such a problem is disclosed by patent document 1, for example.

  As shown in FIG. 8, the resonance coil 901 disclosed in Patent Document 1 includes a coil conductor 910 and an insulating resin 920. The coil conducting wire 910 is wound in a tubular shape a plurality of times. And since this insulating resin 920 is coated on the coil conductor 910 so that the thickness increases as the length of the end 910a in the longitudinal direction of the coil conductor 910 increases, the dielectric strength at the end 910a of the coil conductor 910 is increased. It was possible to prevent spark discharge. The coil conductor 910 of the resonance coil 901 is provided with a certain inter-conductor gap between the winding portions of the coil conductor 910 to prevent spark discharge due to dielectric breakdown between the winding portions of the coil conductor 910. It was out.

  Such a resonance coil 901 is used for, for example, a battery charging system of an electric vehicle, and therefore, downsizing is required for improving fuel efficiency, securing a vehicle interior space, and effectively using a charging area. However, when the resonance coil 901 is downsized, the gap between the conductors of the coil conductor 910 becomes small, and there is a possibility that dielectric breakdown may occur between the coil conductors 910. As a technique for solving such a problem, an insulating member made of an insulating resin or the like is filled between the winding portions of the coil lead wire and molded so as to wrap the entire coil lead wire. There is known a configuration in which the dielectric breakdown resistance (dielectric strength) is improved and the gap between the conductors of the coil conductor is reduced.

JP 2010-73885 A

  However, in the resonance coil having the above-described configuration, as can be seen from FIG. 7, the gap between the coil conductors, that is, the coil conductor gap, although the potential difference generated between the winding portions of the coil conductor differs depending on the location of the coil conductor. Since the thickness of the insulating member filled between the winding portions is made constant according to the largest potential difference, the insulating member becomes excessively thick at the portion where the potential difference is lower than this, and excessive insulation is obtained. Therefore, there is a problem that the manufacturing cost is increased due to wasteful size reduction.

  The present invention aims to solve the above problems. That is, an object of the present invention is to provide a small and inexpensive resonant coil that does not cause dielectric breakdown between coil conductors and a non-contact power transmission device including the same.

  As a result of repeated investigations on the configuration of the resonance coil in order to achieve both reduction in size and cost of the resonance coil, the present inventor has produced different potential differences between the winding portions of the coil conductor. It has been found that by providing an insulating member having an appropriate dielectric strength between the winding portions according to the potential difference between them, it is possible to realize a low cost while having a small shape, and the present invention has been completed.

  In order to achieve the above object, the invention described in claim 1 is a resonance coil that transmits electric power to a counterpart coil by a resonance phenomenon or receives electric power transmitted from the counterpart coil. And between the one winding part of the coil conductor and another winding part adjacent to the one winding part, the one winding part and the other winding part. The resonance coil is characterized in that an insulating member having a dielectric strength corresponding to a potential difference generated between the winding portion and the winding portion is provided.

  According to a second aspect of the present invention, in the first aspect of the present invention, the insulating member is provided with a plurality of sequentially laminated insulating layers having different dielectric strengths. It is what.

  The invention described in claim 3 is the invention described in claim 2, wherein the coil conductor is wound in a tubular shape a plurality of times, and is provided at a central portion in the axial direction of the coil conductor in the insulating member. Further, the dielectric strength of the insulating layer is higher than the dielectric strength of the insulating layer provided at both axial ends of the coil conductor in the insulating member.

  The invention described in claim 4 is the invention described in claim 3, wherein the plurality of insulating layers includes a pair of first insulating layers provided at both axial ends of the coil conductor, and the pair of insulating layers. And a second insulating layer having a dielectric strength higher than that of the pair of first insulating layers, which is laminated so as to be sandwiched between the first insulating layers and provided at a central portion in the axial direction of the coil conductor. Is.

  In order to achieve the above object, the invention described in claim 5 includes a transmission resonance coil that transmits electric power by a resonance phenomenon and a reception resonance coil that receives electric power transmitted from the transmission resonance coil. In the contact power transmission device, at least one of the transmission resonance coil and the reception resonance coil is the resonance coil according to any one of claims 1 to 4, wherein the contact power transmission device is a non-contact power transmission device. .

  According to the first aspect of the present invention, the coil conductor is wound a plurality of times, and one winding portion of the coil conductor and another winding portion adjacent to the one winding portion are provided. Is provided with an insulating member having a dielectric strength according to a potential difference generated between the one winding part and the other winding part. If the insulation strength of the insulation member provided on the coil conductor is made uniform, an insulation member with excessive dielectric strength is provided between some winding portions of the coil conductor. In the present invention, each winding of the coil conductor By providing an insulating member having a dielectric strength that matches the potential difference generated between the portions, a portion having an excessive dielectric strength can be eliminated, and a small and inexpensive resonance coil free from dielectric breakdown between coil conductors can be provided.

  According to the second aspect of the present invention, since the insulating member is provided with a plurality of insulating layers which are sequentially stacked and have different dielectric strengths, the insulating member has a plurality of different dielectric strengths. Thus, a simple structure in which the insulating layers are sequentially stacked can be provided, and a cheaper resonance coil can be provided.

  According to the invention described in claim 3, the coil conductor is wound in a tubular shape a plurality of times, and the dielectric strength of the insulating layer provided in the axial central portion of the coil conductor in the insulating member is applied to the insulating member. Since the dielectric strength of the insulating layer provided at both ends in the axial direction is higher than that of the insulation layer, the potential difference generated between the winding portions of the coil conductor is large at the axial center of the tubular coil conductor, and has a characteristic of decreasing at both ends. In the coil, it is possible to provide a small and inexpensive resonance coil that does not cause dielectric breakdown between coil conductors.

  According to the invention described in claim 4, the plurality of insulating layers are laminated so as to be sandwiched between the pair of first insulating layers provided at both axial ends of the coil conductor and the pair of first insulating layers. And a second insulating layer having a higher dielectric strength than the pair of first insulating layers provided in the central portion of the coil conductor in the axial direction. Therefore, the potential difference generated between the winding portions of the coil conductor is a tubular coil. In the resonance coil having the characteristic that it is large at the axial center part of the conducting wire and small at both ends, the insulation member is made cheaper by adopting a very simple structure with a three-layer insulation material having different dielectric strength A resonant coil can be provided.

  According to the invention described in claim 5, since at least one of the transmission resonance coil and the reception resonance coil is the resonance coil described in any one of claims 1 to 4, a small and inexpensive resonance coil is provided. Can be used to provide a small and inexpensive contactless power transmission device.

It is a perspective view which shows one Embodiment of the resonance coil of this invention. It is a side view of the resonance coil of FIG. It is a figure which shows the structure of the modification of the resonance coil of FIG. 1, Comprising: (a) is a front view of a round planar coil, (b) is a front view of a square planar coil. It is explanatory drawing which shows the structure of the wireless power transmission apparatus which concerns on one Embodiment of the non-contact power transmission apparatus of this invention. It is a block diagram of the wireless power transmission apparatus of FIG. It is explanatory drawing which shows the principle of a resonance-type electric power transmission system. It is a figure which shows typically the voltage distribution in the resonance state in a coil conducting wire. It is a partial expanded sectional view which shows the structure of the conventional resonance coil.

(One Embodiment of Resonance Coil)
Hereinafter, an embodiment of a resonance coil of the present invention will be described with reference to FIGS.

  The resonance coil is used to transmit power to or receive power transmitted from the counterpart coil by using a resonance phenomenon.

  The resonance coil according to the present invention shown in each drawing (indicated by reference numeral 50 in the drawings) includes a coil conductor 51 and a mold member 52 as an insulating member.

  As shown in each drawing, the coil conductor 51 is, for example, an air-core spiral coil having a diameter D of 600 mm and a length L of 200 mm, in which a copper wire having a diameter of 5 mm is wound around a tubular (solenoid) a plurality of times (n times). It is. The coil conductor 51 is provided with winding portions 55 [1] to 55 [n] which are a plurality of circular portions (one turn). Between one winding portion 55 [k] of the coil conductor and another winding portion 55 [k + 1] (k: 1 to n−1) adjacent thereto (hereinafter simply referred to as between the winding portions 55), A certain gap G (that is, a gap) between the conductors is provided. The “constant inter-conductor gap G” means that the inter-conductor gaps G are the same or substantially the same.

  FIG. 7 shows the voltage distribution of the coil conductor 51 in the resonance state. As is clear from FIG. 7, the potential difference between unit distances in the coil conductor 51 (ie, the slope of the graph) is larger at the central portion in the longitudinal direction of the coil conductor 51 (ie, the origin of the graph). It gets smaller as it gets closer to the part. That is, the coil conductor 51 wound in a tubular shape has a different potential difference between the winding portions 55 depending on the location, and specifically, between the winding portions 55 in the central portion in the axial direction (that is, the length L direction). The potential difference is larger than the potential difference between the winding portions 55 at both axial ends.

  As shown in each drawing, the mold member 52 includes a pair of first insulating layers 52a and 52b, and a second insulating layer 52c sandwiched and stacked between the pair of first insulating layers 52a and 52b. Have. The material of the pair of first insulating layers 52 a and 52 b and the second insulating layer 52 c of the mold member 52 is determined in consideration of the characteristics of the coil conductor 51.

  The pair of first insulating layers 52a and 52b is made of, for example, a synthetic resin having medium withstand voltage insulation such as PI (polyimide), and both ends of the coil conductor 51 in the axial direction (that is, the length L direction). Are provided so as to be filled between the winding portions 55 and include the winding portions 55.

  The second insulating layer 52 c is made of, for example, a synthetic resin having a high withstand voltage insulation such as PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer), and is formed at the central portion in the axial direction of the coil conductor 51. It is provided so as to be filled between the winding portions 55 and include the winding portions 55. The second insulating layer 52c is made of a material having higher dielectric strength than the material used for the pair of first insulating layers 52a and 52b.

  The dielectric breakdown voltage (AC) of PI used for the pair of first insulating layers 52a and 52b is about 15 to 20 [kV / mm], and the dielectric breakdown voltage (AC) of PFA used for the second insulating layer 52c. Is about 150 [kV / mm], and on the other hand, the dielectric breakdown voltage (AC) of air is about 3 [kV / mm]. The gap G between the conductors can be made smaller than that of the single 51 configuration.

  For example, the mold member 52 is solidified after the molten PI is poured to a height of about one third of the frame shape in a rectangular parallelepiped frame shape in which the entire coil conductor 51 is accommodated. Thus, the first insulating layer 52b is formed. (2) Next, the molten PFA is poured to a height of about two-thirds of the frame shape and then solidified, thereby forming the second insulating layer 52c. (3) Finally, the molten PI is poured into the frame shape and then solidified, thereby forming the first insulating layer 52a. Thus, the first insulating layers 52 a and 52 b and the second insulating layer 52 c are provided so as to be filled with the synthetic resin forming the respective insulating layers between the winding portions 55 and include the coil conductor 51. That is, according to the characteristic that the mold member 52 has a potential difference between the winding portions 55 at the axial central portion of the coil conductor 51 in the resonance state larger than a potential difference between the winding portions 55 at both axial end portions. The dielectric strength at the axial center of the coil conductor 51 is configured to be higher than the dielectric strength at both axial ends.

  In the present embodiment, the mold member 52 having the first insulating layers 52a and 52b and the second insulating layer 52c is provided as described above. On the other hand, when the mold member 52 is configured so that the dielectric strength is uniform using only the conventional configuration, for example, the PI having a relatively low dielectric strength, the winding portion in the axial central portion of the coil conductor 51 The gap G between conductors (that is, the thickness of the mold member 52 filled between the winding portions 55) is determined in accordance with the potential difference between 55, that is, the largest potential difference. The thickness of the mold member 52 filled between the winding portions 55 is increased, and the outer size (that is, the length L) of the mold member 52 is increased.

  In addition, when the mold member 52 is configured so that the dielectric strength is uniform using only the PFA having a relatively high dielectric strength, the thickness of the mold member 52 filled between the winding portions 55 can be reduced. And the outer size can be reduced. However, a material having a higher dielectric strength is expensive, and the thickness of the mold member 52 filled between the winding portions 55 is the potential difference between the winding portions 55 in the axial central portion of the coil conductor 51. That is, since it is determined in accordance with the largest potential difference, the thickness of the mold member 52 filled between the winding portions 55 is excessive at both ends in the axial direction of the coil conducting wire 51, resulting in waste. End up. Further, even when the PI is used, the same is true with respect to such waste.

  And according to this embodiment, a pair of 1st insulating layer which consists of material with comparatively low dielectric strength at the axial direction both ends of the coil conducting wire 51 about the mold member 52 where the potential difference between the winding parts 55 is comparatively low. 52a and 52b are provided, and in the central portion in the axial direction of the coil conductor 51 having a relatively high potential difference between the winding portions 55, the winding portion 55 is provided by providing a second insulating layer 52c made of a material having a relatively high dielectric strength. An insulating member having a dielectric strength corresponding to the potential difference between them is disposed to eliminate a portion where the dielectric strength is excessive, and both miniaturization and low cost are achieved.

  As mentioned above, according to this invention, it has the coil conducting wire 51 by which the fixed gap | interval gap G was provided between each winding part 55 by several turns, and one winding part of this coil conducting wire 51 is provided. 55 [k] and another winding part 55 [k + 1] adjacent thereto have a potential difference generated between the one winding part 55 [k] and the other winding part 55 [k + 1]. Since the mold member 52 having the appropriate dielectric strength is provided, for example, when the dielectric strength of the mold member 52 provided between the winding portions 55 of the coil conductor 51 is made uniform, a part of the coil conductor 51 is wound. In the present invention, a portion having excessive dielectric strength is provided between the portions 55. In the present invention, the first insulating layer 52a having a dielectric strength in accordance with the potential difference generated between the winding portions 55 of the coil conductor 51, 52b and the second insulating layer 52 The By providing, it is possible to eliminate a portion to be an excess of dielectric strength in the mold member 52 can be an inexpensive resonance coil 50 in a small no dielectric breakdown between the coil wires 51.

  Moreover, since the coil conducting wire 51 is wound in a tubular shape a plurality of times, and the dielectric strength at the axial central portion of the coil conducting wire 51 in the mold member 52 is higher than the dielectric strength at both axial end portions, each winding of the coil conducting wire 51 is performed. In the resonance coil 50 having a characteristic that a potential difference generated between the turning portions 55 is large at the axial center portion of the tubular coil conductor 51 and becomes small at both ends, a small and inexpensive resonance coil without insulation breakdown between the coil conductors 51. 50 can be realized.

  In addition, the mold member 52 is laminated so as to be sandwiched between the pair of first insulating layers 52a and 52b provided at both ends of the coil conducting wire 51 in the axial direction, and the pair of first insulating layers 52a and 52b. And a second insulating layer 52c having a higher dielectric strength than the pair of first insulating layers 52a and 52b, which are provided at the central portion in the axial direction of 51, and are generated between the winding portions 55 of the coil conductor 51. In the resonance coil having the characteristic that the potential difference is large at the axial center portion of the tubular coil conductor and becomes small at both ends, the mold member 52 has a simple configuration in which an insulating material having different dielectric strength is made into a three-layer structure. Thus, a cheaper resonance coil 50 can be realized.

  In the present embodiment, the mold member 52 has a three-layer structure including a pair of first insulating layers 52a and 52b and a second insulating layer 52c. However, the present invention is not limited to this. It is good also as the mold member 52 which has the above several insulating layer. By making the mold member 52 have a simple configuration in which a plurality of such insulating layers are laminated, an inexpensive resonance coil can be realized. In addition, the mold member 52 is not limited to a configuration in which a plurality of insulating layers are stacked, and unless it is contrary to the object of the present invention, according to the voltage distribution of the coil conductor 51, one winding portion 55 [ k] and another winding portion 55 [k + 1] adjacent thereto, and insulation according to a potential difference generated between the one winding portion 55 [k] and the other winding portion 55 [k + 1]. What is necessary is just to be provided with a mold member 52 having proof stress.

  Moreover, in this embodiment, although the fixed gap G between conductors was provided between each winding part 55 of the coil conductor 51, it is not limited to this. For example, the inter-conductor gap G may be different from each other, such as adjusting the inter-conductor gap G together with the dielectric strength of the mold member 52 in accordance with the potential difference between the winding portions 55.

  Moreover, although the coil conducting wire 51 of this embodiment was wound in a tubular shape a plurality of times, it is not limited to this, for example, as shown in FIGS. 3 (a) and 3 (b), The coil conductor 51 is a flat plate in a flat plate-shaped mold member 52 in which the first insulating layer 52b, the second insulating layer 52c, and the first insulating layer 52a are sequentially arranged along the radial direction (the direction radially extending from the center). A flat spiral coil or the like wound a plurality of times in a shape may be used, and the shape of the coil conducting wire 51 is arbitrary as long as it does not contradict the object of the present invention.

(One Embodiment of Non-contact Power Transmission Device)
Next, a wireless power transmission device according to an embodiment of the non-contact power transmission device of the present invention provided with the above-described resonance coil will be described with reference to FIGS.

  FIG. 4 is an explanatory diagram showing the configuration of the wireless power transmission device according to the embodiment of the present invention. As shown in the figure, a wireless power transmission device 10 according to the present embodiment includes a power receiving device 12 provided in an electric vehicle 5 and a power feeding device 11 that supplies AC power to the power receiving device 12. The AC power output from the power feeding device 11 is transmitted to the power receiving device 12 in a non-contact (wireless) manner. The power feeding device 11 includes a communication coil 24 for power transmission. When AC power is supplied to the communication coil 24, the AC power is supplied to the power reception communication coil 31 provided in the power receiving device 12. Is transmitted to.

  The power receiving device 12 provided in the electric vehicle 5 includes a power receiving communication coil 31 that approaches the power transmitting communication coil 24 and a rectifier 33 when the electric vehicle 5 is placed at a predetermined position of the power feeding device 11 during charging. And. Furthermore, a battery 35 charged with DC power, a DC / DC converter 42 that steps down the voltage of the battery 35 and supplies it to the sub-battery 41, an inverter 43 that converts output power of the battery 35 into AC power, A motor 44 driven by AC power output from the inverter 43 is provided.

  FIG. 5 is a block diagram of the wireless power transmission device 10 according to the embodiment of the present invention, which includes a power feeding device 11 and a power receiving device 12 mounted on the electric vehicle 5.

  The power supply apparatus 11 is amplified by a carrier oscillator 21 that outputs a carrier signal for power transmission, a power amplifier 23 that amplifies the carrier signal (that is, AC power) output from the carrier oscillator 21, and the power amplifier 23. A communication coil 24 that outputs AC power is provided. As will be described later, the communication coil 24 includes a feeding coil (primary coil) L1 and a transmission resonance coil X1. And the resonance coil 50 mentioned above is used as this transmission resonance coil X1.

  The carrier oscillator 21 outputs, for example, AC power having a frequency of 1 to 100 [MHz] as an AC signal for power transmission.

  The power amplifier 23 amplifies the AC power output from the carrier transmitter 21. Then, the amplified AC power is output to the communication coil 24. The communication coil 24 cooperates with the communication coil 31 provided in the power receiving device 12 and wirelessly transmits AC power to the communication coil 31 by a resonance type power transmission method. The resonance type power transmission method (that is, the resonance method) will be described later.

  The power receiving device 12 rectifies the AC power received by the communication coil 31 and receives the AC power transmitted from the power transmission communication coil 24, and rectifies the DC voltage. And a rectifier 33 to be generated. Further, a battery 35 that supplies electric power to a vehicle driving motor 44 (see FIG. 4) is provided, and the battery 35 is charged by DC power output from the rectifier 33.

  As will be described later, the communication coil 31 includes a power receiving coil (primary coil) L2 and a receiving resonance coil X2. The above-described resonance coil 50 is used as the reception resonance coil X2.

  Next, the resonance type power transmission method will be described. FIG. 6 is an explanatory diagram showing the principle of the resonant power transmission method. As shown in the figure, the power feeding device 11 is provided with a power feeding coil L1 and a transmission resonance coil X1 (that is, a resonance coil 50) that is disposed concentrically and in proximity to the power feeding coil L1. The power supply coil L1 and the transmission resonance coil X1 constitute the communication coil 24 shown in FIGS. In addition, the power receiving device 12 is provided with a power receiving coil L2 and a receiving resonance coil X2 (that is, a resonance coil 50) disposed concentrically and in proximity to the power receiving coil L2. The power receiving coil L2 and the receiving resonance coil X2 constitute the communication coil 31 shown in FIGS.

  When a primary current is passed through the feeding coil L1, an induced current flows through the transmission resonance coil X1 by electromagnetic induction, and the transmission resonance coil X1 resonates due to the inductance Ls and the stray capacitance Cs of the transmission resonance coil X1. Resonates at a frequency ωs (= 1 / √Ls · Cs). Then, the reception resonance coil X2 on the power receiving device 12 side provided near the transmission resonance coil X1 resonates at the resonance frequency ωs, and a secondary current flows through the reception resonance coil X2. Further, a secondary current flows through the power receiving coil L2 close to the receiving resonance coil X2 due to electromagnetic induction.

  With the above operation, power can be transmitted from the power feeding device 11 to the power receiving device 12 wirelessly.

  Next, the operation of the wireless power transmission device of the present invention shown in FIGS. 4 and 5 will be described. As shown in FIG. 4, the electric vehicle 5 is placed at a predetermined position of the power feeding device 11, and the communication coil 24 provided in the power feeding device 11 and the communication coil 31 provided in the power receiving device 12 of the electric vehicle 5 are opposed to each other. Then, the battery 35 can be charged.

  When charging is started, AC power having a frequency of about 1 to 100 [MHz] is output from the carrier oscillator 21 shown in FIG.

  Then, the AC power output from the carrier transmitter 21 is amplified by the power amplifier 23. The amplified AC power is transmitted to the power receiving device 12 through the communication coils 24 and 31 based on the principle of the resonance power transmission described above.

  The AC power transmitted to the power receiving device 12 is output from the communication coil 31 to the rectifier 33.

  The rectifier 33 rectifies AC power and converts it into DC power of a predetermined voltage, supplies this power to the battery 35, and charges the battery 35. Thereby, the battery 35 can be charged.

  As described above, according to the present invention, since the above-described resonance coil 50 is used as the transmission resonance coil X1 and the reception resonance coil X2, the resonance coil 50 is wound a plurality of times and is constant between the winding portions 55. The coil conductor 51 is provided with a gap G between the conductors, and between one winding portion 55 [k] of the coil conductor 51 and another winding portion 55 [k + 1] adjacent thereto. Since the mold member 52 having a dielectric strength corresponding to the potential difference generated between the one winding portion 55 [k] and the other winding portion 55 [k + 1] is provided, the mold member 52 has an excessive amount. It is possible to eliminate the portion that becomes the dielectric strength, and it is possible to reduce the size of the transmission resonance coil X1 and the reception resonance coil X2 at low cost, and thus it is possible to provide a small and inexpensive non-contact power transmission device.

  In the present embodiment, the resonance coil 50 described above is used for both the transmission resonance coil X1 and the reception resonance coil X2. However, the present invention is not limited to this, and at least one of the transmission resonance coil X1 and the reception resonance coil X2 is used. Any one using the resonance coil 50 may be used.

  In addition, embodiment mentioned above only showed the typical form of this invention, and this invention is not limited to embodiment. That is, various modifications can be made without departing from the scope of the present invention.

5 Electric vehicle 10 Wireless power transmission device (non-contact power transmission device)
50 Resonant coil 51 Coil conductor 52 Mold member (insulating member)
52a, 52b 1st insulating layer 52c 2nd insulating layer X1 Transmission resonance coil (resonance coil)
X2 receiving resonance coil (resonance coil)

Claims (5)

A resonance coil that transmits power to a counterpart coil by a resonance phenomenon or receives power transmitted from the counterpart coil,
Having a coil wire wound several times; and
Between the one winding part of the coil conductor and the other winding part adjacent to the one winding part, there is a potential difference generated between the one winding part and the other winding part. An insulating member having a corresponding dielectric strength is provided.   The resonance coil according to claim 1, wherein the insulating member is provided with a plurality of sequentially stacked insulating layers having different dielectric strengths. The coil conductor is wound into a tube a plurality of times;
The dielectric strength of the insulating layer provided at the axial center of the coil conductor in the insulating member is higher than the dielectric strength of the insulating layer provided at both axial ends of the coil conductor in the insulating member. The resonance coil according to claim 2, characterized in that:   The plurality of insulating layers are stacked so as to be sandwiched between the pair of first insulating layers provided at both ends in the axial direction of the coil conductor and the pair of first insulating layers, and the central portion in the axial direction of the coil conductor. The resonance coil according to claim 3, further comprising: a second insulating layer having a higher dielectric strength than the pair of first insulating layers. In a non-contact power transmission apparatus having a transmission resonance coil that transmits power by a resonance phenomenon, and a reception resonance coil that receives power transmitted from the transmission resonance coil,
5. The contactless power transmission device according to claim 1, wherein at least one of the transmission resonance coil and the reception resonance coil is the resonance coil according to claim 1.

Images