JP5297129B2 - Non-contact power feeding device - Google Patents

Description

  The present invention relates to a non-contact power supply apparatus that includes a pickup unit that is inductively coupled to a power supply line through which a high-frequency current flows, and that supplies power to a load by an induced electromotive force induced in the pickup unit.

  As this type of non-contact power feeding device, a pickup line in which a high-frequency current is supplied from a power supply device is laid in a loop along the moving line of the moving body, and is mounted on the moving body and inductively coupled to the induction line In some cases, power is supplied to a load (an electric motor that moves a moving body) by an induced electromotive force induced by (see, for example, Patent Document 1).

The pickup unit has a rectangular tube-shaped core surrounding the induction line along the circumferential direction, and a coil formed by winding a winding around the core, and most of the magnetic flux generated around the induction line passes through the core. Thus, the induced electromotive force induced in the coil is increased.
Japanese Patent Application Laid-Open No. 11-192866

  By the way, in the pickup part of the conventional example described in Patent Document 1, a coil is formed by winding a winding around the core. There is a risk that the high frequency resistance of the power supply increases and the efficiency of power transmission decreases.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a non-contact power feeding device that can reduce the high-frequency resistance of a coil and improve the efficiency of power transmission.

In order to achieve the above object, a first aspect of the present invention provides a non-contact power feeding device that includes a pickup unit that is inductively coupled to a feeder line through which a high-frequency current flows, and that feeds a load by induced electromotive force induced in the pickup unit The pickup unit includes a cylindrical core surrounding the power supply line along the circumferential direction, a coil formed by winding a winding around the core, and a magnetic shield body surrounding the outside of the core. An opening groove through which the electric wire can pass in the radial direction is provided along the axial direction of the feeder line, both the inner peripheral surface and the outer peripheral surface are formed by curved surfaces, and the cross-sectional shape intersecting the axial direction is formed in a substantially C shape. Furthermore, both ends facing each other across the opening groove are formed so that the area of the cross section along the axial direction is larger than the portion excluding the both ends and does not protrude outside the magnetic shield body. , coils, co Windings, characterized in that formed by single-layer winding respect.

According to the first aspect of the present invention, since the coil is formed by winding the winding on the core in a single layer, the high frequency resistance of the coil is reduced compared to the case where the winding is wound in multiple layers. Thus, the efficiency of power transmission can be improved. Also, compared to the case where the inner peripheral surface and the outer peripheral surface of the core are both configured by abutting a plurality of flat surfaces, the magnetic flux leaking out of the core is reduced, and as a result, power is transferred from the feeder to the pickup unit. Efficiency can be improved and the amount of power supply can be increased. Furthermore, the magnetic flux leaking out of the core can be further reduced, the magnetic resistance at both ends of the core can be relatively reduced, and the magnetic flux leaking out of the core from the opening groove can be reduced. Moreover, the loss can be reduced by suppressing the influence of the external magnetic field on the core and the coil.

  According to the present invention, the high-frequency resistance of the coil can be reduced and the efficiency of power transmission can be improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  The contactless power supply device according to the present embodiment is inductively coupled to a power supply line 100 installed in a loop shape as shown in FIG. 3A, a high-frequency power source 110 that supplies a high-frequency current to the power supply line 100, and the power supply line 100. The pickup unit 1 supplies power to the load (for example, an inverter and a motor) 111 from the pickup unit 1.

  As shown in FIG. 3B, the power supply line 100 includes a cylindrical inner tube portion 101, a cylindrical outer tube portion 102 disposed outside the inner tube portion 101, an inner tube portion 101, and an outer tube portion. The connecting part 103 that connects the two parts 102 so as to be concentric with each other is formed by coating a conductor integrally formed by bending a metal plate with an insulator 104 made of a synthetic resin molded product having a rectangular tube shape. ing. That is, in the feeder line through which high-frequency current flows, there is resistance (high-frequency resistance) due to the skin effect and proximity effect in addition to the electrical resistance of the conductor material (metal plate), but the double tube shown in FIG. If a conductor having a structure is used for the feeder line 100, high-frequency resistance can be reduced and loss can be reduced as compared with a cylindrical conductor.

  The pickup unit 1 includes a core 2, a coil 3, a bobbin 4, a magnetic shield body 5, and a power receiving circuit unit 6. The power receiving circuit unit 6 includes a capacitor that forms a resonance circuit together with the coil 3, a constant voltage circuit that makes the resonance voltage output from the resonance circuit of the coil 3 and the capacitor constant, and the like.

As shown in FIG. 1 (a), the core 2 has both an inner peripheral surface and an outer peripheral surface formed by curved surfaces (cylindrical surfaces), and the cross-sectional shape intersecting the axial direction (direction perpendicular to the paper surface) is substantially C-shaped. Is formed. Here, both end portions 20 and 20 of the core 2 facing each other with the opening groove 2a sandwiched between the end portions 20 of the core 2 excluding the both end portions 20 (hereinafter referred to as “ body portion”) 21 are along the axial direction. The area of the cross section is large.

The bobbin 4 is formed of a rectangular tube-shaped synthetic resin molded product that is curved in an arc shape, and outer casings 40 are provided at both ends in the axial direction. The core 2 is an end of the body 21 after the body portion 21 at a point between the open groove 2a opposite side is divided into two parts, the bobbin 4, 4 to each of the body portions 21 and 21 were extrapolated The cores 2 shown in FIG. 1 (a) are configured by joining together.

The coil 3 is formed by winding a winding having an insulating coating around the bobbins 4 and 4 in a single layer. The step between the end 20 of the core 2 and the body 21 is set larger than the diameter of the winding so that the coil 3 does not protrude beyond the end 20 of the core 2. Thus, since the coil 3 does not protrude outside the end portion 20 of the core 2, magnetic flux leaking from the end portion of the coil 3 to the outside of the end portion 20 of the core 2 can be reduced.

  The magnetic shield body 5 is formed in a substantially cylindrical shape by a metal magnetic material having a high magnetic permeability, and is extrapolated to the core 2 and the coil 3. However, the magnetic shield body 5 is provided with a groove 5a communicating with the opening groove 2a of the core 2 along the axial direction.

  Thus, when a coil is formed by winding a plurality of windings as in the conventional example, the proximity effect may increase the high-frequency resistance of the winding and reduce the efficiency of power transmission. On the other hand, in this embodiment, since the coil 3 is formed by winding a single layer of the winding around the core 2, the high frequency resistance of the coil 3 is reduced compared to the case where the winding is wound in multiple layers. As a result, the efficiency of power transmission can be improved.

  By the way, in the pickup part of the conventional example described in Patent Document 1, a core having a U-shaped cross section is used. In this way, when the inner peripheral surface and the outer peripheral surface of the core are both configured by abutting a plurality of planes, a part of the magnetic flux leaks out of the core at the boundary portion (corner portion) between the plane and the plane. As a result, there is a problem in that the efficiency of power transmission from the feeder line to the pickup unit is reduced.

  That is, when a high frequency current flows through the opening groove 2a to the power supply line 100 disposed inside the core 2, a high frequency magnetic field (magnetic flux φ) is generated on a concentric circle centering on the power supply line 100, and most of the magnetic flux φ is the core. 2 passes along the circumferential direction. At this time, when the inner peripheral surface and the outer peripheral surface of the core 2 ′ are both configured by abutting a plurality of planes as in the conventional example, that is, when the core 2 ′ has a substantially U-shaped cross section, FIG. As shown in (c), a part of the magnetic flux φ leaks out of the core 2 ′ at the boundary portion (corner portion) between the flat surfaces.

  On the other hand, the core 2 in the present embodiment has both an inner peripheral surface and an outer peripheral surface formed of curved surfaces, and a cross-sectional shape that intersects the axial direction is formed in a substantially C shape. The magnetic flux φ leaking to the outside from the portion other than the opening groove 2a is hardly generated. Therefore, compared with the conventional core 2 ′ shown in FIG. 1C, the efficiency of power transmission from the power supply line 100 to the pickup unit 1 can be improved and the power supply amount can be increased. In the present embodiment, both the inner peripheral surface and the outer peripheral surface of the core 2 are configured with curved surfaces, but for example, only the outer peripheral surface may be configured with a curved surface as shown in FIG. Alternatively, as shown in FIG. 2 (b), only the inner peripheral surface may be configured by a curved surface, and the inner peripheral surface and the outer peripheral surface are abutted with a plurality of planes in any of these shapes of the core 2. Compared to the conventional core 2 ′ that is configured, it is possible to reduce the magnetic flux φ leaked to the outside from a portion other than the opening groove 2a. However, it is clear that the core 2 of the present embodiment has the highest power transmission efficiency with respect to these two types of cores 2.

  By the way, in the case where one of the two feed lines 100 going back and forth to the high frequency power supply 110 is arranged inside the core 2 and the other feed line 100 is arranged in the vicinity of the pickup unit 1. The magnetic flux generated around the other power supply line 100 cancels out with the magnetic flux φ passing through the core 2, and as a result, the power transmission efficiency of the pickup unit 1 may be reduced. On the other hand, in this embodiment, since the core 2 and the coil 3 are covered with the magnetic shield body 5 and are magnetically shielded, the magnetic flux φ passing through the core 2 is an external magnetic field (magnetic flux) as described above. It is possible to prevent cancellation, and as a result, loss can be reduced.

In the present embodiment, the opening groove 2a is provided in the core 2 of the pickup unit 1 so that the power supply line 100 can be easily attached to and detached from the feeder line 100. However, the portion (gap) of the opening groove 2a has a magnetic circuit. The magnetic resistance is greatly increased. Therefore, in the present embodiment, both end portions 20 and 20 of the core 2 facing each other across the opening groove 2a are formed to have a larger cross-sectional area along the axial direction than the body portion 21 excluding the both end portions 20 of the core 2. Thus, the magnetic resistance at both ends 20 and 20 of the core 2 is relatively reduced as compared with the body portion 21, and the magnetic flux leaking out of the core 2 from the opening groove 2a is reduced.

1A and 1B show an embodiment of the present invention, in which FIG. 1A is a cross-sectional view of a pickup unit partially omitted, FIG. 1B is an explanatory diagram of magnetic flux passing through the core in the above, and FIG. It is explanatory drawing of magnetic flux. (A), (b) is a top view which shows another structure of the core in the same as the above. (A) is a whole block diagram same as the above, (b) is sectional drawing of the feeder in the same as the above.

Explanation of symbols

1 Pickup part 2 Core 2a Opening groove 3 Coil

Claims (1)

In a non-contact power supply apparatus that includes a pickup unit that is inductively coupled to a power supply line through which a high-frequency current flows, and that supplies power to a load by an induced electromotive force induced in the pickup unit.
The pickup unit has a cylindrical core surrounding the power supply line along the circumferential direction, a coil formed by winding a winding around the core, and a magnetic shield body surrounding the outside of the core ,
The core has an opening groove through which at least the feed line can pass in the radial direction is provided along the axial direction of the feed line, and both the inner peripheral surface and the outer peripheral surface are formed of curved surfaces and have a cross-sectional shape that intersects the axial direction. Further, both ends facing each other across the opening groove have a larger cross-sectional area along the axial direction and do not protrude outside the magnetic shield body. Is formed,
The non-contact power feeding device, wherein the coil is formed by winding a single layer of a winding around a core .

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