JP2010075017A - Non-contact power supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the efficiency of power transmission from a power supply line to a pickup section than in a device in the prior art, and increasing a power supply amount. <P>SOLUTION: A core 2 has a structure in which both an inner circumferential surface and an outer circumferential surface are each formed of a curved surface (cylindrical surface) and a cross sectional shape is a substantial C shape crossing in an axial direction (direction perpendicular to a sheet face). With this configuration, a magnetic flux ϕ leaking from a portion other than an opening groove to the outside hardly occurs. Thus, this apparatus has the improved efficiency of power transmission from the power supply line 100 to the pickup section 1 and can increase power supply amount, compared to a conventional core 2' in which an inner circumferential surface and outer circumferential surface are both formed by butting a plurality of planes. <P>COPYRIGHT: (C)2010,JPO&INPIT

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, for example, there is one described in Patent Document 1. In Patent Document 1, a power supply line (feeder) for passing a high-frequency current is stretched along a mobile line of a mobile unit, and a pickup unit inductively coupled to the power supply line is arranged in the mobile unit. The load (electric motor that moves the moving unit) is fed by the induced electromotive force induced in the pickup unit.

The pickup unit has a cylindrical core surrounding the power supply 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 power supply line passes through the core. The induced electromotive force induced in the coil is increased. The core is provided with an opening groove along the axial direction of the power supply line so that at least the power supply line can pass in the radial direction so that the pickup portion can be easily attached to and detached from the power supply line. .
Special table 2003-528555 gazette

  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.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the efficiency of power transmission from the power supply line to the pickup unit and increase the power supply amount compared to the conventional case. To provide an apparatus.

  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 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 and a coil formed by winding a winding around the core, and the core has an opening through which at least the power supply line can pass in the radial direction. The groove is provided along the axial direction of the feeder line, and at least one of the inner peripheral surface and the outer peripheral surface is formed of a curved surface.

  According to the invention of claim 1, since at least one of the inner peripheral surface or the outer peripheral surface of the cylindrical core is formed of a curved surface, both the inner peripheral surface and the outer peripheral surface of the core are plural as in the conventional example. Compared with the case where the planes are configured to face each other, the magnetic flux leaking out of the core can be reduced. As a result, the efficiency of power transmission from the power supply line to the pickup unit can be improved and the power supply amount can be increased as compared with the conventional case.

  According to a second aspect of the present invention, in the first aspect of the invention, the core is configured such that both the inner peripheral surface and the outer peripheral surface are curved surfaces, and the cross-sectional shape intersecting the axial direction is formed in a substantially C shape. And

  According to invention of Claim 2, the magnetic flux which leaks out of a core can further be reduced.

  The invention of claim 3 is the invention of claim 1 or 2, in which both ends of the core facing each other across the opening groove have a larger cross-sectional area along the axial direction than portions excluding the both ends of the core. It is formed.

  According to invention of Claim 3, the magnetic resistance in the both ends of a core can be reduced relatively, and the magnetic flux which leaks out of an opening groove | channel from a core can be reduced.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the coil is formed by winding a single layer of a winding around a core.

  According to the invention of claim 4, the high-frequency resistance of the coil can be reduced as compared with the case where the winding is wound in multiple layers.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects of the present invention, the pickup section includes a magnetic shield body that surrounds the outside of the core.

  According to the invention of claim 5, 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, it is possible to improve the efficiency of power transmission from the power supply line to the pickup unit and to increase the power supply amount as compared with the prior art.

  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 across the opening groove 2a are more along the axial direction than portions (hereinafter referred to as “body portions”) 21 excluding the both end portions 20 of the core 2. 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 has a body portion 20 divided into two at the opposite side of the opening groove 2a, and the end portions of the body portions 20, 20 after the bobbins 4, 4 are extrapolated to the body portions 20, 20, respectively. 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 21 of the core 2 and the body 20 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 high frequency current flows through the opening groove 2a to the power supply line 100 arranged 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. Passes through the core 2 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 ends 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 barrel 21 excluding the both ends 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 2 a is reduced.

  Furthermore, when a coil is formed by winding multiple windings, the high frequency resistance of the winding may increase due to the proximity effect, which may reduce the efficiency of power transmission. Therefore, in the present embodiment, by forming the coil 3 by winding a single layer of the winding around the core 2, the high frequency resistance of the coil 3 is reduced as compared with the case where the winding is wound in multiple layers, and as a result The transmission efficiency can be improved.

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 (5)

In a non-contact power feeding device that includes a pickup unit that is inductively coupled to a power feed line through which a high-frequency current flows, and that feeds 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, and a coil formed by winding a winding around the core.
The core is provided with an opening groove through which at least a power supply line can pass in a radial direction along the axial direction of the power supply line, and at least one of an inner peripheral surface or an outer peripheral surface is configured by a curved surface. Contact power supply device.   2. The non-contact power feeding apparatus according to claim 1, wherein the core has both an inner peripheral surface and an outer peripheral surface formed of curved surfaces, and a cross-sectional shape intersecting the axial direction is formed in a substantially C shape.   3. The cross-sectional area along the axial direction is formed larger at both end portions of the core facing each other across the opening groove than at a portion excluding the both end portions of the core. 4. Non-contact power feeding device.   The contactless power supply device according to any one of claims 1 to 3, wherein the coil has a single layer wound around a core.   The non-contact power feeding apparatus according to claim 1, wherein the pickup unit includes a magnetic shield body that surrounds the outside of the core.

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