JP7150276B2 - Wireless power supply device and multi-axis robot using it - Google Patents

Description

The present invention relates to a wireless power supply device and a multi-axis robot using the same.

Conventionally, a wireless power supply device that supplies power in a contactless manner using electromagnetic induction, magnetic field resonance, electric field coupling, or the like is known. For example, Patent Literature 1 discloses a wireless power supply device using electric field coupling. In such electric field coupling, a high frequency is used for power transmission from the power transmitting electrode portion to the power receiving electrode portion. Therefore, in the case of electric field coupling, highly accurate impedance matching is required between the power transmitting side and the power receiving side. By the way, when the power consumed by the loads connected to the power receiving side changes every second or the number of loads changes, the impedance of the power receiving side changes accordingly. In such a case, it is required to always supply a constant voltage to the load even if the impedance changes.

However, in the conventional case, the input impedance and the power supplied fluctuate due to changes in load impedance and the number of loads. Therefore, a large-scale variable matching box is required to cope with changes in input impedance. Further, when the supplied power changes, feedback control of the inverter, which is the source of the high frequency, is required.

JP 2018-68079 A

Therefore, it is an object of the present invention to provide a wireless power supply device and a multi-axis robot using the same, in which the voltage of the load is kept constant by the function of an equivalent ideal transformer regardless of changes in the load on the power receiving side, and the structure is simplified. do.

In the wireless power feeder of the present embodiment, a circuit corresponding to an equivalent ideal transformer is composed of a power transmitting electrode section and a power receiving electrode section that are involved in electric field coupling, and a specific circuit section. That is, the electrode portion having the power transmitting electrode portion and the power receiving electrode portion configures the electrode equivalent circuit portion as a capacitor, which is a capacitive element. At this time, the specific circuit section configures an equivalent ideal transformer together with the electrode equivalent circuit section including the electrode section. As a result, the load connected to the output side of the specific circuit section is regarded as being connected to a high-frequency power supply section that generates a high-frequency signal with a constant voltage amplitude across an equivalent ideal transformer. That is, one or more loads are considered to be connected in parallel to the high-frequency power supply with an equivalent ideal transformer interposed therebetween. As a result, even if the number or magnitude of loads connected to the output side of the electrode section, ie, the power receiving electrode side, changes, the electrode equivalent circuit section having the electrode section as a capacitor is not affected by changes in the imaginary component. Therefore, regardless of changes in the load on the power receiving side, the function of the equivalent ideal transformer keeps the voltage of the load constant, thereby simplifying the structure.

Schematic diagram showing an electrical configuration of a wireless power supply device according to one embodiment Schematic perspective view showing a multi-axis robot to which a wireless power supply device according to one embodiment is applied Schematic diagram showing an electrical configuration of a robot to which a wireless power supply device according to one embodiment is applied Schematic diagram showing an electrical configuration of a wireless power supply device according to one embodiment Schematic diagram showing an equivalent circuit of the wireless power feeder shown in FIG. Schematic diagram showing the equivalent circuit of the robot shown in FIG.

Embodiments of a wireless power feeder and a multi-axis robot using the same will be described below with reference to the drawings.
FIG. 1 shows a wireless power supply device 10 according to one embodiment. The wireless power supply device 10 includes a power transmission side unit 11 and a power reception side unit 12 . The power transmission side unit 11 has a high frequency power supply section 13 and a power transmission electrode section 14 . The high frequency power supply unit 13 generates a high frequency with a constant voltage amplitude. A high frequency generated by the high frequency power supply unit 13 is supplied to the power transmission electrode unit 14 . The power transmission electrode section 14 is made of, for example, a metal plate, and outputs the high frequency generated by the high frequency power supply section 13 .

The power receiving unit 12 includes a power receiving electrode section 15 and a load 16 . The power receiving electrode portion 15 is provided facing the power transmitting electrode portion 14 . The space between the power transmitting electrode portion 14 and the power receiving electrode portion 15 facing each other is filled with air, and electric power is transmitted in a non-contact manner by electric field coupling. That is, the power receiving electrode section 15 receives the high frequency output from the power transmitting electrode section 14 by electric field coupling. Since there is no contact between the power transmitting electrode portion 14 and the power receiving electrode portion 15 facing each other as described above, a capacitor filled with air, which is an insulator, is formed. The power transmitting electrode portion 14 and the power receiving electrode portion 15 constitute an electrode portion 17 .

The wireless power supply device 10 configures the following electrode equivalent circuit section 20 in the power transmission side unit 11 and the power reception side unit 12 . That is, the electrode equivalent circuit section 20 is configured with a power transmission inter-electrode capacitance section 21 and a power reception inter-electrode capacitance section 22 using a pair of the power transmission electrode section 14 and the power reception electrode section 15 that constitute the electrode section 17 as a capacitor. The power transmission inter-electrode capacitance section 21 and the power reception inter-electrode capacitance section 22 may each have a capacitor as a capacitive element, or may be an apparent capacitor formed between a pair of circuit wirings. The power transmitting electrode portion 14 and the power receiving electrode portion 15 constituting the electrode portion 17 are set to have the same electrical capacity. Thus, in the wireless power supply device 10, the electrode equivalent circuit section 20 is configured by the power transmission electrode section 14 and the power reception electrode section 15 that constitute the electrode section 17, and the power transmission electrode inter-electrode capacitance section 21 and the power reception inter-electrode capacitance section 22. ing.

The wireless power supply device 10 includes a specific circuit section 23 . The specific circuit section 23 is inserted between the high-frequency power supply section 13 and the electrode section 17 in the power transmission side unit 11 . Specifically, the specific circuit section 23 has a series coil 24 and a parallel coil 25 . The series coil 24 is inserted in series between the high frequency power supply section 13 and the electrode section 17 . Also, the parallel coil 25 is inserted in parallel between the high-frequency power supply section 13 and the electrode section 17 . The specific circuit section 23 constitutes a circuit corresponding to a transformer together with the electrode equivalent circuit section 20 by the series coil 24 and the parallel coil 25 . Thereby, the specific circuit section 23 constitutes an equivalent ideal transformer 26 together with the electrode equivalent circuit section 20 .

The load 16 is connected to the output side of the specific circuit section 23 in the power receiving unit 12 . That is, the load 16 is connected to the output side of the electrode section 17 in the power receiving side unit 12 and consumes the power received by the power receiving electrode section 15 . The load 16 includes, for example, a drive device such as a motor, a power storage device such as a battery, and a control device that controls them. Also, the load 16 may have various circuits such as a rectifier circuit section that rectifies high frequencies into direct current.

The wireless power supply device 10 as described above is applied to, for example, a multi-axis robot. FIG. 2 shows a three-axis robot 30 as an example of a multi-axis robot to which the wireless power supply device 10 is applied. When the wireless power supply device 10 is applied to the robot 30, the power transmission side unit 11 including the high frequency power supply section 13, the power transmission electrode section 14, and the like is fixed to equipment or the like. The power transmission electrode portion 14 of the wireless power supply device 10 is provided on a rail 31 extending in the X-axis direction. The robot 30 has an intermediate movable part 32 that moves along rails 31 . The intermediate movable portion 32 reciprocates along the rail 31 in the X-axis direction. The power receiving electrode portion 15 is provided on the intermediate movable portion 32 and faces the power transmitting electrode portion 14 provided on the rail 31 . The intermediate movable portion 32 also has a power transmission electrode portion 33 . The power transmission electrode portion 33 relays and transmits the power that the intermediate movable portion 32 receives at the power reception electrode portion 15 . The power transmission electrode portion 33 of the intermediate movable portion 32 extends in the Y-axis direction perpendicular to the X-axis. The terminal movable portion 34 has a power receiving electrode portion 35 . The power receiving electrode portion 35 of the terminal movable portion 34 faces the power transmitting electrode portion 33 of the intermediate movable portion 32 . The power receiving electrode portion 35 of the terminal movable portion 34 may be movable or fixed with respect to the power transmitting electrode portion 33 of the intermediate movable portion 32 .

With such a configuration of the robot 30 , the robot 30 receives power from the wireless power supply device 10 in a contactless manner. Specifically, the intermediate movable portion 32 of the robot 30 receives power from the power transmitting electrode portion 14 while moving along the rail 31 by the power receiving electrode portion 15 . The power transmitting electrode portion 33 of the intermediate movable portion 32 outputs at least part of the power received by the power receiving electrode portion 15 from the power transmitting electrode portion 33 . The terminal movable portion 34 receives the power output from the power transmitting electrode portion 33 of the intermediate movable portion 32 at the power receiving electrode portion 35 . Thereby, in the three-axis robot 30 , the intermediate movable portion 32 receives power from the power transmission electrode portion 14 and the terminal movable portion 34 receives power from the intermediate movable portion 32 . The wireless power supply device 10 applied to such a three-axis robot 30 is shown as an electrical circuit as shown in FIG.

Next, the operation of the wireless power supply device 10 configured as described above will be described.
As shown in FIG. 4 , the electrode equivalent circuit section 20 forms a capacitor with the power transmission electrode section 14 and the power reception electrode section 15 of the electrode section 17 . The capacitance of the capacitor in the entire electrode portion 17 is assumed to be C _S . Therefore, when forming a pair of electrode portions 17 as in this embodiment, the capacitance of one capacitor is 2C _S . In the electrode equivalent circuit section 20, the capacitance of the power transmission inter-electrode capacitance section 21 and the power reception inter-electrode capacitance section are respectively C _P . Further, the specific circuit section 23 has a series coil 24 and a parallel coil 25 . The inductance of the series coil 24 is L _S and the inductance of the parallel coil 25 is L _P . Coupling coefficient k between power transmitting electrode portion 14 and power receiving electrode portion 15 in electrode portion 17 of electrode equivalent circuit portion 20 is represented by the following equation (1).

When the coupling coefficient k is set in this way, the inductance L _S (H) of the series coil 24 in the specific circuit section 23 is determined by the following formula (2), and the inductance L _P (H) of the parallel coil 25 is determined by the following formula (3). The inductance L _S of the series coil 24 and the inductance L _P of the parallel coil 25 are set to satisfy these equations (2) and (3), respectively.

As a result, the electrode equivalent circuit section 20 and the specific circuit section 23 are one impedance conversion circuit with an impedance conversion ratio of N and an input impedance of Z _in (Ω) as shown in the following equation (4). Acts as a transformer.

Accordingly, FIG. 5 shows an equivalent circuit showing the entire wireless power supply device 10 shown in FIGS. That is, the equivalent circuit of the wireless power supply device 10 is regarded as a state in which a resistance is connected to the high frequency power supply unit 13 as the load 16 . 6 shows an equivalent circuit of the robot 30 to which the wireless power supply device 10 shown in FIG. 3 is applied. That is, the equivalent circuit of the wireless power supply device 10 is considered to be a state in which a resistance as the load 16 is connected in parallel to the high frequency power supply unit 13 . Therefore, even if the number of loads 16 increases from the state shown in FIG. 1 to the state shown in FIG. It is assumed that only the number of loads 16 connected in parallel to 13 has changed.

As described above, in the wireless power supply device 10 of the present embodiment, the power transmitting electrode section 14 and the power receiving electrode section 15 involved in electric field coupling and the specific circuit section 23 constitute a circuit corresponding to a transformer. That is, the electrode portion 17 having the power transmitting electrode portion 14 and the power receiving electrode portion 15 constitutes the electrode equivalent circuit portion 20 as a capacitor, which is a capacitive element. At this time, the electrode equivalent circuit section 20 including the specific circuit section 23 and the electrode section 17 has a function corresponding to the equivalent ideal transformer 26 . As a result, the load 16 connected to the output side of the specific circuit section 23 is considered to be connected to the high-frequency power supply section 13 that generates a high-frequency signal with a constant voltage amplitude across the transformer. That is, one or more loads 16 are considered to be connected in parallel to the high-frequency power supply unit 13 with the equivalent ideal transformer 26 interposed therebetween. As a result, even if the number of loads 16 or the size of the loads 16 connected to the output side of the electrode section 17, i.e., the power receiving electrode section 15 side, changes, the electrode equivalent circuit section 20 using the electrode section 17 as a capacitor will not generate the imaginary component. Not affected by change. Therefore, regardless of changes in the load 16 on the power receiving side, the function of the equivalent ideal transformer 26 makes the voltage of the load 16 on the power receiving side constant, thereby simplifying the structure.

Further, in the robot 30 to which the wireless power supply device 10 of the present embodiment is applied, cables or wiring are provided between the fixed portion such as the rail 31 and the intermediate movable portion 32, and between the intermediate movable portion 32 and the terminal movable portion 34, respectively. Electric power and signals are transmitted in a non-contact manner without using Therefore, it is possible to suppress an increase in weight due to cables, wiring, etc., and to reduce the stoppage of equipment due to disconnection of cables and wiring.

The present invention described above is not limited to the above-described embodiments, and can be applied to various embodiments without departing from the gist of the present invention.
Although the present disclosure has been described with reference to examples, it is understood that the present disclosure is not limited to such examples or structures. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations and configurations, as well as other combinations and configurations, including single elements, more, or less, are within the scope and spirit of this disclosure.

In the drawings, 10 is a wireless power supply device, 13 is a high frequency power supply unit, 14 and 33 are power transmitting electrode units, 15 and 35 are power receiving electrode units, 16 is a load, 17 is an electrode unit, 20 is an electrode equivalent circuit unit, and 23 is a specific 24 is a series coil; 25 is a parallel coil; 26 is an equivalent ideal transformer; and 30 is a robot (multi-axis robot).

Claims (3)

a high frequency power supply section (13) for generating a high frequency with a constant voltage amplitude;
A power transmitting electrode unit (14) for transmitting the high frequency generated by the high frequency power supply unit (13), and a power receiving electrode unit (15) for receiving the power of the high frequency output from the power transmitting electrode unit (14) in a non-contact manner by electric field coupling. an electrode portion (17) having
A specific circuit section (23) forming a circuit corresponding to an equivalent ideal transformer (26) together with the electrode equivalent circuit section (20) when an electrode equivalent circuit section (20) having the electrode section (17) as a capacitor is formed. When,
a load (16) connected to the output side of the equivalent ideal transformer (26);
A wireless power supply device comprising: The specific circuit section (23) includes a series coil (24) inserted in series and a parallel coil (25) inserted in parallel between the high-frequency power supply section (13) and the electrode section (17). The wireless power supply device according to claim 1, comprising: A multi-axis robot comprising the wireless power supply device (10) according to claim 1 or 2.

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