JP2005269857A - Non-contact power feeder apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-contact feeder apparatus capable of improving the efficiency of feeding to a power receiving coil section by reducing the magnetic resistance of a magnetic circuit with a closed magnetic path formed by a core. <P>SOLUTION: This feeder apparatus supplies electric power to coils 3, 4 wound around the cores from feeders 5, 6 with no contact by means of electromagnetic induction. The two cylindrical cores 1, 2 are provided side by side and the coils 3, 4 are wound around the respective cores 1, 2 to form the power receiving coil section. Moreover, the feeders 5, 6 are provided so as to be passed through the respective cores 1, 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a non-contact power supply device, and more particularly to a non-contact power supply device that reduces the magnetic resistance of a magnetic circuit by a closed magnetic circuit formed by a core and improves the power supply efficiency to a power receiving coil unit.

For example, when power is constantly supplied to the load in a non-contact manner, as shown in Patent Document 1 below, the power supply line is installed so that the E-type core is straddled, and the transfer device moves along the power supply line.
Such a power supply device is suitable for long-distance conveyance, but in order to support the power supply line, an opening is formed in a part of the core to form an E-type open magnetic circuit, so that the magnetic resistance of the magnetic circuit is reduced. There is a disadvantage that power supply efficiency decreases due to an increase in gap spacing.

Also, when cascade-connecting exciting currents of power supply lines to a plurality of moving bodies that move more than two axes, in Patent Document 2 below, the received power at the previous stage is supplied to a high-frequency power source and connected to the subsequent stage with this high-frequency power source. An excitation current is passed through the power supply line, or a high-frequency voltage generated by power reception at the previous stage is transformed with a transformer, and the power supply line connected to the subsequent stage is excited.
However, when the voltage is transformed by a transformer, there is a drawback that the received voltage cannot be stabilized. In addition, when a high frequency power supply is used separately, the cost of the power supply is generated.

JP-A-9-93704 Japanese Patent Laid-Open No. 7-2311

  The present invention provides a non-contact power supply apparatus that reduces the magnetic resistance of a magnetic circuit by a closed magnetic circuit formed by a core and improves the power supply efficiency to a power receiving coil unit in view of the problems of the conventional non-contact power supply apparatus. The purpose is to do.

  In order to achieve the above object, a contactless power supply device according to the present invention includes two cylindrical cores in a contactless power supply device that supplies power to a coil wound around a core in a contactless manner by electromagnetic induction from a power supply line. The power receiving coil portion is formed by winding the coils around each core to form a power receiving coil portion, and a feed line is installed so as to penetrate each core.

  In this case, the moving range of the power receiving coil portion can be covered with a non-magnetic housing.

  In a non-contact power supply device that cascades the excitation current of the power supply line to a plurality of moving bodies that move more than two axes, the power receiving coil section at the front stage and the power supply line at the rear stage are connected in series, and the power supply line at the rear stage A resonance circuit current can be allowed to flow.

  According to the non-contact power supply device of the present invention, in the non-contact power supply device that supplies electric power to the coil wound around the core in a non-contact manner by electromagnetic induction from the power supply line, two cylindrical cores are connected in series. Each coil is wound around a core to form a power receiving coil part, and since a power supply line is installed so as to penetrate each core, the magnetic resistance of the magnetic circuit is reduced by the closed magnetic circuit formed by the core, and the power receiving coil part The power feeding efficiency can be improved.

  In this case, by covering the moving range of the power receiving coil portion with a non-magnetic housing, it is possible to shield the power receiving coil portion and prevent contact between the power receiving coil portion and a person.

  In a non-contact power supply device that cascades the excitation current of the power supply line to a plurality of moving bodies that move more than two axes, the power receiving coil section at the front stage and the power supply line at the rear stage are connected in series, and the power supply line at the rear stage By supplying the resonance circuit current, the power supply device for the subsequent power supply line can be omitted, and a substantially constant current can be supplied to the power supply line in the subsequent stage regardless of the size of the load in the previous stage, so that stable excitation can be performed.

  Hereinafter, embodiments of the non-contact power feeding device of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the non-contact power feeding device of the present invention.
This non-contact power supply device supplies power to the coils 3 and 4 wound around the cores 1 and 2 from the power supply lines 5 and 6 by electromagnetic induction in a non-contact manner. The coils 3 and 4 are wound around the cores 1 and 2 to form a power receiving coil portion, and the feeder lines 5 and 6 are installed so as to penetrate the cores 1 and 2.

Specifically, the power receiving coil portion in which the coils 3 and 4 are wound around the cores 1 and 2 baked with ferrite are passed through the forward feed line 5 and the return feed line 6. The feed line is excited by flowing a high-frequency current through the feed line from the high-frequency power source 7. The frequency of the high frequency power supply 7 uses a frequency in the vicinity of 10 kHz, but may be a frequency higher than that.
In the core 1 and the core 2, the current passing direction is opposite, so that the outputs of the coils 3 and 4 are connected in series or in parallel with the polarity reversed.
The cores 1 and 2 can be used by connecting two cores having exactly the same shape, or the effect is not changed even if the two cores are integrally molded and fired.
Ferrite cores have excellent high frequency characteristics and high electrical resistance, so there is little loss due to eddy currents. It is possible to operate even with a core in which silicon steel plates are laminated in the direction through which the coil penetrates. Silicon steel plates have the advantage that the saturation magnetic flux density is higher than that of ferrite materials. In the central part in the vertical direction, a magnetic field can be generated only on a plane perpendicular to the feeder line. However, as it moves away from the center, a magnetic field in the direction of the feeder line is generated, and eddy current loss due to this magnetic field increases. A silicon steel sheet is not suitable for the shape of the receiving coil portion having a length equal to or higher than the coil height.
Lamination of silicon steel sheets is also effective when the shape is short (approximately 1/5 or less) of the core height or long (approximately 5 times or more).

FIG. 2 shows a method of placing the power receiving coil portion in a casing that covers the power receiving coil portion and the power feeding line.
For example, the power receiving coil portion and the power supply line are placed in a cover 8 made of a nonmagnetic material such as aluminum and provided with a notch in the lower portion.
The cover 8 can be easily made of an extruded material made of aluminum, and serves as a shield that does not let the noise of the feeder line be exposed to the outside. The power receiving coil portion is fixed to the linear guide 11 by a fixing member 9 made of a nonmagnetic material such as aluminum. The linear guide rail 10 is fixed to the cover 8.

In this embodiment, the range of the section to be fed is assumed to be about 2 m, and within this range, the feed line 5 has a structure in which one end is fixed and tension is applied from the other end. The position of the feeder line is lowered to the positions 5 ′ and 6 ′ by its own weight in the central portion of the feeding section.
Ferrite is a material with high hardness, and when it comes into contact with the power supply line, it damages the insulation of the power supply line, so if there is a possibility of contact due to vibration, etc., there is little friction such as fluororesin on the inner surface of the core The power supply line can be protected by pasting the sheet material 12 to the core.
In addition, FIG. 2 shows a case where the power supply line is installed in the horizontal direction. However, in the case where the power supply line is installed in the vertical direction, the position of the power supply line does not change due to gravity, but the vibration and acceleration during the operation of the device. In order to prevent contact, a sheet material that also covers the coil portion is appropriately used.

  Further, as shown in FIG. 3, the feeders 5 and 6 are not one, but a plurality of wires are used, and the equivalent primary current is passed through the cores 1 and 2 a plurality of times (n times). The current can be increased by a factor of n and the current can be multiplied by n. Thus, a high-frequency power supply with a small output current can be used for large-capacity power feeding.

FIG. 4 shows the overall structure of the non-contact power feeding device.
The power receiving coil portion moves in the cover 8.
The feeder lines 5 and 6 are fixed on the near side (not shown). The folded portion of the power supply line at the other end is half-fixed with a spring 14 so as to maintain the gap, and tension is applied to support the power supply line so that it passes through the core without drooping.

FIG. 5 shows an outline of a non-contact power feeding apparatus in which the present embodiment is applied and the exciting current of the power feeding line is cascade-connected to a plurality of moving bodies that move in two or more axes.
A linear actuator 16 that is driven by a linear motor or the like is disposed on both sides of the main body 15, and a portal gantry 17 moves in the direction of the arrow. Furthermore, the linear actuator 19 is provided thereon, and the movable part 21 moves.
As equipment having a structure that operates at an arbitrary position in the XY axis plane, there is a chip mounter for mounting electronic components on a printed wiring board.
The power of the movable part is supplied from the non-contact power feeding devices 18 and 20 provided alongside the linear actuator.

FIG. 6 shows the connection of this non-contact power feeding device.
The power supply line 24 in the previous stage is excited by the high-frequency power source 7 provided in the apparatus main body, and the power is received by the power receiving coil unit 22 in the previous stage.
The front feed line 24 and the power receiving coil portion 22 correspond to the power feeding device 18, and the rear feed wire 25 and the power receiving coil portion 23 correspond to the power feeding device 20.
The receiving coil portion 22 at the front stage and the feeder line 25 at the rear stage are connected in series, and a resonance circuit is formed by the series inductance and the resonance capacitor 26, and the resonance capacitor 26 is selected so that the resonance frequency is in the vicinity of the high frequency power supply 7. . The saturable reactor 27 stabilizes the voltage of the resonance circuit at a constant value. Therefore, a substantially constant current flows through the feeder line 25 regardless of the load of the load 28.
In the conventional method shown in Patent Document 2 described above, since no resonance current does not flow through the high-frequency transformer, the current of the power supply line 25 has a drawback that differs greatly between no load and load. Stable excitation is achieved by connecting the receiving coil in series.
The load 28 corresponds to the power source of the linear actuator 19 and sensors necessary for its control. Further, another actuator, sensors, control device and the like are arranged on the movable portion 21, and these correspond to the load 31. .
The power receiving coil unit 23 forms a resonance circuit with the resonance capacitor 29, and the resonance capacitor 29 has a resonance frequency by the power receiving coil unit 23 and the resonance capacitor 29 near the frequency of the current flowing through the feeder line 25, that is, the frequency of the high frequency power supply 7. Select as follows.
As described above, the non-contact power feeding apparatus according to the present embodiment can realize a plurality of power feedings without using a high-frequency transformer or another power source in a cascade power feeding configuration.

FIG. 7 shows a method for manufacturing the power receiving coil portion.
In general, it is not preferable to integrally mold a large ferrite core because a large press facility is required, manufacturers that can be manufactured are limited, and costs are high. Therefore, a method of increasing the size by assembling a plurality of small cores is realistic.
For example, as shown in FIG. 7 (a), four U-shaped cores are used, and coils 3 and 4 are wound around the two cores, and are fastened and fixed with an adhesive or a stainless steel belt.
Further, as shown in FIG. 7B, coils 3 and 4 are wound around the I type of the E type and I type cores, and are bonded or fastened with a stainless steel belt.
Alternatively, as shown in FIG. 7 (c), two U-shaped and I-shaped coils are wound around the I-shaped coils 3, 4 and bonded or fastened with a stainless steel belt.
Compared with the method of winding a coil around a core with a square hole, these methods involve bonding or fastening, but the coil winding work is wound around an open core, so the work is simple and automated. Is also possible.
Incidentally, the length of the receiving coil portion that can be manufactured at a low cost is limited to about 30 mm for ferrite, and more than that, a plurality of stages of ferrite are bonded to cope with long coil manufacturing.

By the way, in the magnetic circuit which comprises a closed magnetic circuit, the inductance of a receiving coil part changes with the errors of the magnetic permeability of a core material, and a processing dimension.
If the power receiving coil unit is used as a transformer, a secondary voltage can be obtained based on the turns ratio of the primary coil and the secondary coil. However, when used as an inductance constituting a resonance circuit, an inductance error is a fluctuation of the resonance frequency. It becomes a factor and is not preferable.
By providing a narrow gap in a part of the closed magnetic path, a series circuit of the magnetic permeability of the core, the magnetic resistance that can be obtained in the cross-sectional area, and the magnetic resistance by the gap is configured, and the magnetic resistance of the gap can be controlled by the gap of the gap. The relative permeability of the core is as large as about 2000 to 3000 with respect to the relative permeability 1 of the air gap.

Core magnetic path length: Lc = 0.2 m
Void: Lg = 0.5 × 10 ⁻³ m,
Cross-sectional area of core and gap: S = 1000 mm ² = 1 × 10 ⁻³ m ²
Core relative permeability: μ = 2000
The magnetic resistance R is
R≈ (0.2 / (2000 × 1 × 10 ⁻³ )) + (0.5 × 10 ⁻³ ) / (1 × 10 ⁻³ ) ≈0.1 + 0.5≈0.6
become.
When the relative permeability μ of the core fluctuates by 10% from 2000 to 1800, 0.1 in the first term fluctuates by approximately 11% from 0.111.
However, the magnetoresistance R is
R≈0.111 + 0.5≈0.611
And is relaxed to a fluctuation of about 2% with respect to 0.6.
In the calculation of the magnetic resistance R, the vacuum magnetic permeability μ ₀ (μ ₀ = 4π × 10 ⁻⁷ H / m) is omitted because it is a common term included in both the core and the air gap.

Thus, by providing the air gap, the inductance is reduced with respect to a completely closed magnetic circuit, but a homogeneous power receiving coil portion with little individual difference in inductance can be manufactured.
In addition, the coil characteristics due to fluctuations in magnetic permeability and saturation magnetic flux density due to temperature, which is a disadvantage of ferrite materials, can be similarly mitigated by providing air gaps.
Such a fine gap can easily constitute a gap with high dimensional accuracy by sandwiching a non-magnetic insulator such as a ceramic plate or an epoxy resin plate when bonding the core.
In addition, the inductance can be adjusted to a constant inductance value by adjusting the number of turns of the coil.

  As mentioned above, although the non-contact electric power feeder of this invention was demonstrated based on several Example, this invention is not limited to the structure described in the said Example, The structure described in each Example is combined suitably. For example, the configuration can be changed as appropriate without departing from the spirit of the invention.

  The non-contact power feeding device of the present invention has a characteristic of suppressing an increase in magnetic resistance of a magnetic circuit by a closed magnetic circuit and preventing a decrease in power feeding efficiency. It can be suitably used for a transfer device or a robot that minimizes dust.

It is an enlarged view which shows one Example of the non-contact electric power feeder of this invention. It is sectional drawing which shows the non-contact electric power feeder. It is sectional drawing of the non-contact electric power feeder which made the electric power feeding line plural. It is a perspective view which shows the whole non-contact electric power feeder. It is a perspective view which shows one Example of the non-contact electric power feeder of this invention applied to the some mobile body. It is explanatory drawing which shows the electrical connection of the non-contact electric power feeder. It is an exploded view which shows the manufacture example of a receiving coil part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Core 2 Core 3 Coil 4 Coil 5 Feed line 6 Feed line 7 High frequency power supply 8 Cover 9 Fixing member 10 Rail 11 Linear guide 12 Sheet material 13 Holder 14 Spring 15 Main body 16 Linear actuator 17 Gantry 18 Non-contact power supply device 19 Linear actuator DESCRIPTION OF SYMBOLS 20 Non-contact electric power feeder 21 Movable part 22 Power receiving coil part of the front | former stage 23 Power receiving coil part of the back | latter stage 24 Power feed line of the front | former stage 25 Power feed line of the back | latter stage 26 Resonance capacitor 27 Saturable reactor 28 Load 29 Resonance capacitor 30 Saturable reactor 31 Load

Claims (3)

  In a non-contact power supply device that supplies power in a non-contact manner by electromagnetic induction from a power supply line to a coil wound around a core, two cylindrical cores are connected in series, and a coil is wound around each core to receive a coil portion A non-contact power feeding device characterized in that a feed line is installed so as to penetrate each core.   The contactless power feeding device according to claim 1, wherein a moving range of the power receiving coil portion is covered with a nonmagnetic housing.   In a non-contact power feeding device that cascades the excitation current of a power feed line to a plurality of moving bodies that move more than two axes, the power receiving coil section of the front stage and the power feed line of the rear stage are connected in series, and a resonance circuit is connected to the power feed line of the rear stage. The contactless power feeding device according to claim 1, wherein an electric current is allowed to flow.

Images