JPWO2014057587A1 - Contactless power supply - Google Patents

Abstract

To provide a non-contact power feeding device capable of continuous power feeding. In a non-contact power feeding device that supplies electric power from a power feeder 51 to a power receiver 41 using an electromagnetic induction interaction, a resin 12, a primary coil 11 enclosed in the resin 12, and a resin together with the primary coil 11 A first conductor 25 having a higher thermal conductivity than the resin 12 and a second conductor that is in contact with the first conductor 25 inside the resin 12 and exposed to the outside of the resin 12. The power supply 51 is provided with the body 14.

Description

  The present invention relates to a non-contact power feeding apparatus that supplies electric power by utilizing electromagnetic induction interaction.

  The non-contact power feeding apparatus includes a power feeder that houses a primary coil and a power receiver that houses a secondary coil, and supplies power from the power feeder to the power receiver based on electromagnetic induction interaction. Is.

  In this type of non-contact power supply device, the power receiver is, for example, an electric mobile body (for example, a vehicle, a construction machine (eg, a hydraulic excavator), an industrial machine (eg, a forklift), or the like provided with a power storage device such as a secondary battery. ) And the power feeder may be installed in a charging facility (for example, a charging stand) equipped with a power source. In this case, the power feeder (primary coil) is mainly installed outdoors, and is used in a harsh environment exposed to temperature and humidity changes, dust, wind and rain, and the like. Therefore, it is preferable that the primary coil made of metal (conductive wire) is molded with a material such as a resin having excellent weather resistance to block contact with the outside.

  Although not created based on this viewpoint, as a non-contact power feeding device using a molded coil (molded coil), a conductor composed of a plurality of uninsulated wires is wound, A non-contact power supply coil molded with an insulator is disclosed (Japanese Patent Laid-Open No. 2012-043966). By configuring in this way, a coil can be formed without insulating each of a plurality of strands, so that the labor of manufacturing is greatly simplified compared to a coil in which each strand is insulated, The cost can be reduced

JP 2012-043966 A

  When an alternating current is passed through the coil molded with resin as described above, the temperature of the coil rises. The coil heated in this way is cooled to some extent by the diffusion of heat to the outside through the mold resin.

  However, the heat generation of the coil increases in proportion to the energization time of the alternating current (that is, the charging time) and its frequency. Since the resin has a lower thermal conductivity than the metal, the coil may be insufficiently cooled depending on the energization time and frequency. Further, the resin heated by the coil may be damaged.

  As a measure for avoiding such a situation, for example, it is conceivable to limit the energization time to the coil, but a charging facility on the premise that charging of a plurality of electric mobile bodies is continuously performed It is not preferable that a limit is set for the charging time of the power feeder. Although it is conceivable to construct a system that uses a plurality of power feeders alternately, it is not preferable in that the initial cost of the charging facility increases. In addition, although the problem which generate | occur | produces in a charging facility was assumed here, it cannot be overemphasized that the same problem will arise if it is a system with which electric power feeding from a power feeder to a power receiver is performed continuously.

  An object of the present invention is to provide a non-contact power feeding device capable of continuous power feeding.

  In order to achieve the above object, the present invention provides a resin, a coil enclosed in the resin, a first conductor enclosed in the resin together with the coil, and having a higher thermal conductivity than the resin, The first conductor is in contact with the inside of the resin, and the second conductor is exposed to the outside of the resin.

  According to the present invention, the heat generated in the coil enclosed in the resin can be easily discharged to the outside of the resin, so that the power feeding operation can be continued.

BRIEF DESCRIPTION OF THE DRAWINGS The whole block diagram of the non-contact electric power feeding system which concerns on embodiment of this invention. Sectional drawing of the mold coil 21 which concerns on the 1st Embodiment of this invention. The perspective view of the mold coil 21 which concerns on the 1st Embodiment of this invention. Sectional drawing of 21 A of molded coils which concern on the 2nd Embodiment of this invention. Sectional drawing of the mold coil 21B which concerns on the 3rd Embodiment of this invention. Sectional drawing of the mold coil 21C which concerns on the 4th Embodiment of this invention. Sectional drawing of mold coil 21D which concerns on the 5th Embodiment of this invention. Sectional drawing of the mold coil 21E which concerns on the 6th Embodiment of this invention. Sectional drawing of the mold coil 21F which concerns on the 7th Embodiment of this invention. Sectional drawing of an example of the primary coil 11 which concerns on embodiment of this invention. Sectional drawing of the other example of the primary coil 11 which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an overall configuration diagram of a non-contact power feeding system according to an embodiment of the present invention. The non-contact power feeding system shown in this figure is to supply electric power wirelessly to a moving body 40 such as an electric vehicle using electromagnetic induction interaction, and is installed in a charging facility (charging stand) 50 on the ground side. The power feeder 51 and the power receiver 41 mounted on the moving body 40 are provided. The power feeder 51 and the power receiver 41 may be collectively referred to as a non-contact power feeding device. Although the case where the moving body 40 is a large electric vehicle will be described here, a rechargeable power storage device is provided such as a medium-sized / small-sized vehicle, a construction machine such as a hydraulic excavator and a wheel loader, an industrial machine such as a forklift. Others can be used as long as they are good.

  The power feeder 51 is fixed so as not to move relative to the ground 60, and is connected to the power source 23 via an inverter device (control device) 52. The inverter device 52 and the power source 23 are installed in the charging facility 50. As the power source 23, for example, an AC power source can be used. The power feeder 51 accommodates a primary coil 11 (see FIG. 2 and the like) formed by winding a wire (electric wire) having electrical conductivity in an annular shape, and is supplied from a power source 23 via an inverter device 52. A magnetic field is generated around the primary coil by the alternating current. In addition, although the inverter apparatus 52 and the power supply 23 of FIG. 1 are embed | buried under the ground, you may install these on the ground.

  The power receiver 41 is connected to the power storage device 42 via an inverter device (control device) 43. The inverter device 43 and the power storage device 42 are mounted on the moving body 40. As the power storage device 42, for example, a secondary battery such as a lithium ion battery or a capacitor can be used. The power receiver 41 is provided with a secondary coil (not shown) formed by winding a wire (electric wire) having electrical conductivity in an annular shape.

  When the moving body 40 is moved to an appropriate position and the secondary coil of the power receiver 41 is arranged opposite to the primary coil 11 of the power feeder 51 and the current flowing through the primary coil 11 is changed, the primary coil ( The magnetic field generated by the power feeder 51) changes, a current (inductive current) flows through the secondary coil, and the power storage device 42 is charged. The electric power stored in the power storage device 42 is supplied to an electric machine such as a motor 44 connected to the inverter device 43 for use. Here, the case where power is supplied from the power storage device 42 to the motor 44 for driving the wheels of the moving body 40 will be described. However, the power supply target of the power storage device 42 may be another electric machine installed in the moving body 40 good.

  The power receiver 41 shown in FIG. 1 is installed on the bottom surface of the moving body 40, but if installed on the moving body 40, it is installed on another place (for example, the side surface or top surface of the moving body 40). May be. In that case, it goes without saying that the installation location of the power feeder 51 in the charging facility 50 is changed in accordance with the installation location of the power receiver 41. The power feeder 51 in FIG. 1 is fixed to the ground 60 so that the height of the upper surface is equal to or lower than the ground surface.

  FIG. 2 is a cross-sectional view of the molded coil 21 according to the first embodiment of the present invention, and FIG. 3 is a perspective view thereof. The same parts as those in the previous figure may be denoted by the same reference numerals and description thereof may be omitted (the same applies to the subsequent figures).

  The molded coil 21 shown in FIGS. 2 and 3 is formed (molded) with the resin 12 having excellent weather resistance, and is provided in the power feeder 51. The molded coil 21 includes a primary coil 11 sealed in the resin 12, a first conductor 25 sealed in the resin 12 together with the primary coil 11, and a second conductor 14 exposed to the outside from the resin 12. And a radiator 15 connected to the outer end of the second conductor 14.

  The primary coil 11 is a flat coil formed by winding an electric wire around a central axis 31 in a substantially circular shape. It is preferable that the electric wire or the whole of the primary coil 11 is covered with an insulator (for example, see FIGS. 10 and 11 described later). The primary coil 11 according to the present embodiment is formed in a circular shape, but may be formed in a rectangular shape, a square shape, an elliptical shape, or the like. Moreover, as a material of the electric wire which concerns on the primary coil 11, in order to reduce the eddy current loss by a skin effect, a litz wire is suitable.

  Examples of the resin 12 used for the mold coil 21 include unsaturated polyester resin, epoxy resin, fluororesin, ABS resin, acrylic resin, polyethylene, and polypropylene. Note that the mold coil may be formed of another material, and a paint having excellent weather resistance such as a fluorine-based paint, acrylic, or acrylic urethane may be applied to the surface thereof. Of course, these paints may be applied to a resin having excellent weather resistance.

  The first conductor 25 is a good conductor of heat and electricity, and is formed in a disk shape having the same central axis as the central axis 31 of the primary coil 11. In the example shown in FIG. 2, the first conductor 25 is brought into contact with the primary coil 11 covered with an insulator based on the viewpoint of promoting the exhaust heat effect, but they may be separated from each other. Further, as the first conductor 25, a conductor having a thermal conductivity higher than that of the resin 12 is used. For example, it is preferable to use a metal such as copper or aluminum. Further, the first conductor 25 is preferably a non-magnetic material from the viewpoint of suppressing the generation of eddy current due to the induced current, and aluminum is particularly suitable from this viewpoint.

  The second conductor 14 is a good conductor of heat and electricity, is in contact with the first conductor 25 inside the resin 12, and is exposed to the outside of the resin 12. The second conductor 14 of the present embodiment is a linear conductor, one end of which is coupled to the bottom surface of the first conductor 25 inside the resin 12, and the other end radiates heat outside the resin 12. It is connected to the body 15. As the second conductor 14, a conductor having a thermal conductivity higher than that of the resin 12 is used. For example, a metal is preferable. In addition, heat transfer is more important than conductivity due to the nature of its use. Further, since the other end of the second conductor 14 is exposed to the outside, it is assumed that the second conductor 14 is used in a harsh environment. Therefore, it is preferable to use a metal having excellent weather resistance such as stainless steel.

  The radiator 15 is for accelerating the release of heat transmitted from the first conductor 25 via the second conductor 14. The heat dissipating body 15 shown in the figure includes a plurality of fins arranged at predetermined intervals on the left and right side surfaces of the rectangular parallelepiped, thereby increasing the surface area, thereby improving the heat dissipating effect. The material of the radiator 15 is preferably a material having high thermal conductivity and excellent weather resistance, and may be formed of, for example, an aluminum alloy having excellent corrosion resistance. The heat radiator 15 may be fixed in the atmosphere or may be embedded in the ground. In the latter case, the heat radiation effect is improved as compared with the former case.

  In addition, the heat radiator 15 is not limited to the shape shown in the drawings, but may be any other shape as long as it is suitable for heat radiation. Further, the radiator 15 may be a water-cooled cooling device by forming a cooling water channel inside the radiator 15. Further, in the present embodiment, the example in which the heat radiating body 15 is attached to the second conductor 14 has been described. However, since the heat radiating function is ensured to some extent if the second conductor 14 is exposed to the outside, The body 15 may be omitted.

  According to the power feeder 51 according to the present embodiment configured as described above, the heat generated in the primary coil 11 even when the energization time of the primary coil 11 is prolonged and there is significant heat generation. Can be discharged from the first conductor 25 to the outside of the molded coil 21 through the second conductor 14. Accordingly, since heating of the resin 12 is suppressed, continuous energization, that is, continuous power supply to the power receiver 41 can be performed.

  In addition, the first conductor 25 contributes to improving the rigidity of the molded coil 21 and serves as a reference for the attachment position of the primary coil 11, thereby facilitating the manufacturing process.

  FIG. 4 is a sectional view of a molded coil 21A according to the second embodiment of the present invention. The molded coil 21A shown in this figure is different from that of the previous embodiment in that it has a core 16 formed of a magnetic material.

  The core (magnetic body) 16 is enclosed in the resin 12 together with the primary coil 11 and is formed in a plate shape in the present embodiment. The core 16 is disposed on one end face side (end face side far from the power receiver 41) in the primary coil 11. In addition, as a material of the core 16, in order to suppress an eddy current, the ferrite with high electrical resistance is suitable.

  Even if the molded coil 21 </ b> A is configured in this way, it is possible to continuously supply power to the power receiver 41 as in the first embodiment.

  FIG. 5 is a sectional view of a molded coil 21B according to the third embodiment of the present invention. The molded coil 21B shown in this figure is different from the previous embodiment in that it includes a first conductor 25B having a cylindrical side surface. The material of the first conductor 25B is particularly preferably aluminum as in the first embodiment.

  Even if the molded coil 21 </ b> B is configured in this way, it is possible to continuously supply power to the power receiver 41 as in the first embodiment. In particular, when the first conductor 25B having a side surface surrounding the primary coil 11 from the outer periphery is used as in the present embodiment, the first conductor 25B can easily function as a high-frequency shield. Can be reduced.

  FIG. 6 is a sectional view of a molded coil 21C according to the fourth embodiment of the present invention. The molded coil 21C shown in this figure differs from the previous embodiment in that it includes the second conductor 14C.

  The end 44 on the first conductor 25 side in the second conductor 14 </ b> C is connected to a position where the central axis 31 of the primary coil 11 passes on the bottom surface of the first conductor 25. In the present embodiment, since the center axis 31 of the primary coil 11 passes through the center of the disk-shaped first conductor 25, the end 44 of the second conductor 14 </ b> C is connected to the primary coil 11 and the first coil 11. One conductor 25 is located at the center of both.

  Even if the molded coil 21 </ b> C is configured in this manner, it is possible to continuously supply power to the power receiver 41 as in the first embodiment. In particular, since the position of the end portion 44 of the second conductor 14C is located at the center of the primary coil 11 and the first conductor 25, the primary coil 11 can be uniformly cooled.

  FIG. 7 is a sectional view of a molded coil 21D according to the fifth embodiment of the present invention. The mold coil 21D shown in this figure is different from the previous embodiment in that it includes a plurality of second conductors 14d1 and 14d1 to which heat radiating bodies 15d1 and 15d2 are attached.

  A heat radiator 15d1 is connected to the second conductor 14d1, and a heat radiator 15d2 is connected to the second conductor 14d2. Other configurations related to the second conductors 14d1 and 14d2 and the heat radiators 15d1 and d2 are the same as those described in the first embodiment. If the mold coil 21D is configured in this way, the exhaust heat effect of the first coil 11 can be improved as compared with the first embodiment.

  From the viewpoint of cooling the primary coil 11 equally, the positions where the two second conductors 14d1 and 14d2 are connected to the first conductor 25 are point-symmetric with respect to the central axis 31. It is preferable to set to. In the example shown in FIG. 7, the two second conductors 14 d 1 and 14 d 2 are connected to the first conductor 25, but three or more may be used. In this case, it goes without saying that the exhaust heat effect improves as the number of the second conductors 14 increases.

  FIG. 8 is a sectional view of a molded coil 21E according to the sixth embodiment of the present invention. The molded coil 21E shown in this figure is different from the previous embodiment in that the lead wire 20 of the primary coil 11 is connected to the power source 23 while being in contact with the second conductor 14E.

  The lead wire 20 is coated with an insulator. The lead wire 20 is led from one surface side (surface on the power receiver 41 side) of the first conductor 25 to the other surface side through the hole 34 provided in the first conductor 25 inside the resin 12. , In contact with the second conductor 14E connected to the other surface. The lead wire 20 is exposed from the inside of the molded coil 21 (resin 12) to the outside while maintaining contact with the second conductor 14E. The lead wire 20 is connected to the power source 23 while being in contact with the second conductor 14E even after being guided to the outside of the mold coil 21.

  When the mold coil 21E is configured in this manner, exhaust heat through the lead wire 20 is promoted, so that the exhaust heat effect of the primary coil 11 can be improved as compared with the first embodiment.

  The lead wire 20 may be in contact with the first conductor 25 in addition to or instead of the second conductor 14. Further, in the example shown in the figure, the lead wire 20 and the second conductor 14E are brought into contact with each other until the lead wire 20 reaches the power source 23 outside the mold coil 21. You may quit contact. That is, the second conductor 14 and the power source 23 are not necessarily connected. When the hole 34 is not provided in the first conductor 25, the lead wire 20 may be guided along the surface of the first conductor 25 and guided to the second conductor 14E.

  FIG. 9 is a cross-sectional view of a molded coil 21F according to the seventh embodiment of the present invention. The molded coil 21F shown in this figure is different from the previous embodiment in that the lead wire 20 of the primary coil 11 is connected to the power source 23 after contacting the second conductor 14F and the heat radiator 15F.

  The lead wire 20 is led from the inside of the molded coil 21 (resin 12) to the outside while being in contact with the second conductor 14F as in the sixth embodiment. The second conductor 14F is connected to the heat radiating body 15F outside the molded coil 21, and a through hole 35 for passing the lead wire 20 is provided inside the heat radiating body 15F. The lead wire 20 is led to the outside of the molded coil 21, and then passes through the through hole 35 while being in contact with the second conductor 14 </ b> F, and is connected to the power source 23.

  Even if the mold coil 21F is configured in this way, the exhaust heat through the lead wire 20 is promoted, so that the exhaust heat effect of the primary coil 11 can be improved as compared with the first embodiment.

  In the present embodiment, the case where the lead wire 20 is introduced into the through hole 35 provided in the heat radiating body 15F has been described. However, the lead wire 20 is arranged so as to contact the heat radiating body 15F without providing the through hole 35. May be installed.

By the way, the primary coil 11 which concerns on said each embodiment is demonstrated using FIG.
FIG. 10 is a cross-sectional view of an example of the primary coil 11 according to the embodiment of the present invention, and corresponds to a view of the cross-section of the primary coil 11 from the direction of the arrow X in FIG. The primary coil 11 shown in this figure is obtained by winding a coil conductor 17 having a substantially rectangular cross section around a central axis 31 once, and an outer periphery of the coil conductor 17 is covered with an insulator (coil insulation) 18. Has been. Thereby, the primary coil 11 and the 1st conductor 25 or the core 16 can be insulated.

  FIG. 11 is a cross-sectional view of another example of the primary coil 11 according to the embodiment of the present invention, in which the primary coil 11 is viewed from the same direction as FIG. The primary coil shown in this figure is obtained by winding a coil conductor (conductive wire) 17A having a substantially circular cross section around the central axis 31 10 times, and an insulator (coil insulation) 18A is provided on the outer periphery of the coil conductor 17A. Is covered. The coil conductor 17A is molded with resin 19 on the outer periphery of the insulator 18A. Even if the primary coil 11 is configured in this way, it can be insulated as in the case of FIG.

  Here, the case where the primary coil 11 is formed by winding the single conductor 17 </ b> A 10 times has been described, but the primary coil 11 is formed by overlapping two conductors wound five times. There is no particular limitation on the number of wires and the number of turns.

  By the way, in each said embodiment, although demonstrated on the premise of the mold coil 21 (primary coil) of the electric power feeder 51, the secondary coil by the side of the power receiver 41 is also comprised like said each embodiment. In this case, it goes without saying that the same effect as described above can be obtained.

  The present invention is not limited to the embodiments described above, and includes various modifications within the scope not departing from the gist of the present invention. For example, the present invention is not limited to the one having all the configurations described in the above embodiment, and includes a configuration in which a part of the configuration is deleted. In addition, part of the configuration according to one embodiment can be added to or replaced with the configuration according to another embodiment.

  DESCRIPTION OF SYMBOLS 11 ... Primary coil, 12 ... Resin, 14 ... 2nd conductor, 15 ... Radiator, 16 ... Core, 17 ... Coil conductor, 18 ... Coil insulator, 19 ... Resin, 20 ... Coil opening, 21 ... Mold coil , 23 ... power source, 31 ... coil central axis, 41 ... power receiver, 42 ... power storage device, 43 ... inverter device, 44 ... motor, 50 ... charging facility, 51 ... power feeder, 52 ... inverter device, 60 ... ground

Claims (7)

Resin,
A coil enclosed in the resin;
A first conductor encapsulated in the resin together with the coil, having a higher thermal conductivity than the resin;
A non-contact power feeding device comprising: a second conductor that is in contact with the first conductor inside the resin and exposed to the outside of the resin. The contactless power supply device according to claim 1,
The non-contact electric power feeder further provided with the heat radiator attached to the said 2nd conductor outside the said resin. The contactless power supply device according to claim 1,
The first conductor has a side surface that surrounds the coil from the outer periphery. The contactless power supply device according to claim 1,
The non-contact power feeding device, wherein the second conductor is connected to the first conductor at a position where a central axis of the coil passes. The contactless power supply device according to claim 1,
The non-contact power feeding device according to claim 1, wherein the lead wire of the coil is in contact with the second conductor in the resin. The contactless power supply device according to claim 1,
The non-contact power feeding device, wherein the first conductor is in contact with the coil. The contactless power supply device according to claim 1,
A non-contact power feeding apparatus, further comprising: a core disposed on one end face side of the coil and formed of a magnetic material.

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