JP7660886B2 - Power receiving apparatus, sensor device, power supply system, and power receiving method - Google Patents

Description

The present invention relates to a power receiving device that is wirelessly powered by a power supply device, a sensor device having a power receiving device and installed in a machine tool, a power supply system having a power supply device and a power receiving device, and a power receiving method by the power receiving device.

In the field of machine tools, sensor devices are installed at each location. The results of detection by the sensor devices are input to a dedicated controller or computer via a distribution board equipped with a PLC (Programmable Logic Controller). In recent years, there has been a demand to use various sensor devices to collect data that changes from moment to moment in real time (see Patent Document 1).

JP 2019-46293 A

In the field of machine tools, sensor devices are installed at each location, and multiple sensor devices are installed on each of the many machine tools in a factory. This means that the number of sensor devices in a factory becomes large. In order to constantly monitor the many machine tools in a factory, it is necessary to provide a stable power supply to the many sensor devices.

In view of the above, the object of the present invention is to provide a stable power supply to a sensor device.

A power receiving device according to one embodiment of the present invention includes:
a power receiving antenna that wirelessly receives electricity wirelessly supplied from a power supply device;
A number of different converters, each of which converts a different voltage to a constant voltage;
an input switching unit that inputs the electricity received by the power receiving antenna to a converter capable of converting a voltage of the electricity;
Equipped with:

According to this embodiment, the input switching unit switches the voltage input to multiple different converters that convert different voltage values into a constant voltage. This allows the multiple different converters to convert a wide range of voltages into a constant voltage with high efficiency across the entire range, regardless of the value of the received voltage.

the input switching unit includes a plurality of different Zener diodes respectively connected to the plurality of different converters;
The plurality of different Zener diodes may each input to a converter connected to the Zener diode a voltage that the converter can convert.

According to this embodiment, one Zener diode extracts a voltage according to the value of the receiving voltage and inputs the voltage to one converter. This allows the Zener diode to automatically input a voltage to one converter without the need for information processing to determine the one converter to which the voltage should be input. Therefore, no power is required for information processing.

The power receiving device may further include a storage device that stores the electricity of the constant voltage output by the multiple different converters.

The storage device may be a capacitor.

According to this embodiment, multiple different converters can convert a wide range of voltages to a constant voltage (a voltage suitable for a capacitor, which is a storage device) with high efficiency over the entire range, regardless of the value of the received voltage.

A sensor device according to one aspect of the present invention comprises:
a power receiving antenna for receiving electricity wirelessly supplied from a power supply device;
A number of different converters, each of which converts a different voltage to a constant voltage;
an input switching unit that inputs the electricity received by the power receiving antenna to a converter capable of converting a voltage of the electricity;
a storage battery that stores electricity of the constant voltage output from the plurality of different converters;
A power receiving device having
a sensor element to which the electricity stored in the capacitor is supplied;
Equipped with:

The sensor device is installed in a machine tool,
The sensor element may detect vibration, acceleration, rotation speed and/or temperature of the machine tool.

A power supply system according to an embodiment of the present invention includes:
A power supply device;
a power receiving antenna for receiving electricity wirelessly supplied from the power supply device;
A number of different converters, each of which converts a different voltage to a constant voltage;
an input switching unit that inputs the electricity received by the power receiving antenna to a converter capable of converting a voltage of the electricity;
A power receiving device having
Equipped with:

The power receiving device is
The power supply system further includes a storage device that stores electricity of the constant voltage output from the plurality of different converters,
The power supply may be included in a sensor device having a sensor element to which the electricity stored in the capacitor is supplied.

The power supply system may include a plurality of the power receiving devices.

In a factory, sensor devices are installed at each location of the machine tools, and multiple sensor devices are installed on each of the many machine tools in the factory. As a result, firstly, the number of sensor devices in the factory becomes large. Secondly, when wirelessly supplying power from one power supply device to the power receiving devices built into each of the many sensor devices in the factory, the distance from the power supply device to each of the power receiving devices varies. Even under such circumstances, it is possible to stably supply power to many sensor devices that are at different distances from the power supply device, and it is possible to constantly monitor the many machine tools in the factory.

A power receiving method according to one embodiment of the present invention includes:
The power receiving antenna receives the electricity wirelessly supplied by the power supply device,
an input switching unit inputs the voltage of the electricity received by the power receiving antenna to a converter capable of converting the voltage among a plurality of different converters that convert different voltages into a constant voltage;
The converter converts the input voltage to the constant voltage.

The present invention makes it possible to provide a stable power supply to a sensor device.

Note that the effects described here are not necessarily limited to those described herein and may be any of the effects described in this disclosure.

1 illustrates a power supply system according to an embodiment of the present invention. 1 shows a schematic diagram of a plurality of sensor devices arranged on a machine tool; 1 shows the configuration of a sensor device incorporating a power receiving device.

The following describes an embodiment of the present invention with reference to the drawings.

1. Power supply system

Figure 1 shows a power supply system according to one embodiment of the present invention.

The power supply system 1 is typically installed in a factory. The power supply system 1 has a power supply device 40 and one or more power receiving devices 30.

The power supply device 40 wirelessly supplies electricity to the power receiving device 30.

The one or more power receiving devices 30 are each included in a sensor device 10 installed in one or more machine tools in a factory. The one or more power receiving devices 30 wirelessly receive and store electricity wirelessly supplied by the power supply device 40 (details will be described later). Although there are typically multiple one or more power receiving devices 30, the following description will be limited to a single power receiving device 30 unless otherwise specified.

The sensor device 10 is installed in a machine tool that includes, for example, a spindle. The sensor element included in the sensor device 10 detects, for example, the vibration, acceleration, rotation speed, and/or temperature of the machine tool that includes the spindle. Specific examples of the type and arrangement of the sensor device 10 are described below.

2. Type and placement of sensor devices

Figure 2 shows a schematic diagram of multiple sensor devices arranged on a machine tool.

One vibration sensor device 10A and four temperature sensor devices 10B are arranged on the front side 81F of the spindle 81. The vibration sensor device 10A is arranged, for example, on the front side of the rotation axis of the spindle 81. As the four temperature sensor devices 10B, for example, one contact type temperature sensor is arranged in front of the front inner wheel, a separate contact type temperature sensor is arranged on the rear side of the front inner wheel, one non-contact type temperature sensor is arranged in front of the front outer wheel, and a separate non-contact type temperature sensor is arranged on the rear side of the front outer wheel. These five sensor devices 10 are connected to one child tag 20A, for example, by wire. The child tag 20A wirelessly transmits the detection results of the connected multiple sensor devices 10 to a parent tag (not shown) connected to a personal computer (not shown) or the like.

One vibration sensor device 10A and four temperature sensor devices 10B are arranged on the rear side 81R of the spindle 81. The vibration sensor device 10A is arranged, for example, on the rear side of the rotation axis of the spindle 81. As the four temperature sensor devices 10B, for example, one contact type temperature sensor is arranged on the front side of the rear inner wheel, a separate contact type temperature sensor is arranged on the rear side of the rear inner wheel, one non-contact type temperature sensor is arranged on the front side of the rear outer wheel, and a separate non-contact type temperature sensor is arranged on the rear side of the rear outer wheel. These five sensor devices 10 are connected to separate child tags 20B, for example, by wires. The child tag 20B wirelessly transmits the detection results of the connected multiple sensor devices 10 to a parent tag (not shown) connected to a personal computer (not shown) or the like.

The sensor device 10 is typically a MEMS (Micro Electro Mechanical Systems). In this embodiment, the sensor device 10 is configured using MEMS and the child tag 20 is made wireless, so that the sensor device 10 and the child tag 20 can be placed on a rotating part such as the spindle 81 of a machine tool to detect the vibration and/or acceleration and temperature of the spindle 81.

3. Power supply system concept

In the above example, ten sensor devices 10 are installed at each location of the spindle 81. In this way, sensor devices are installed at each location of the machine tool, and multiple sensor devices 10 are installed on each of the many machine tools in the factory. Therefore, firstly, the number of sensor devices 10 in the factory becomes large. Secondly, when wirelessly supplying power from one power supply device 40 to the power receiving devices 30 built into each of the many sensor devices 10 in the factory, the distance from the power supply device 40 to each of the power receiving devices 30 is different. Even under such circumstances, in order to constantly monitor the many machine tools in the factory, it is necessary to stably supply power to the many sensor devices 10 that are at different distances from the power supply device 40.

According to Coulomb's law, the electricity supplied from the power supply device 40 to the power receiving device 30 is inversely proportional to the square of the distance from the power supply device 40 to the power receiving device 30. In other words, when power is supplied wirelessly from the power supply device 40 to the power receiving device 30, the further away from the power supply device 40, the greater the loss of electricity output by the power receiving device 30. For example, if the distance from the power supply device 40 to the power receiving device 30 is doubled, the electricity output by the power supply device 40 is attenuated to 1/4, and if the distance from the power supply device 40 to the power receiving device 30 is tripled, the electricity output by the power supply device 40 is attenuated to 1/9.

The voltage also varies depending on the distance from the power supply device 40 to the power receiving device 30. For example, when the distance from the power supply device 40 to the power receiving device 30 is 10 m or more, the voltage of the received electricity is significantly reduced. For this reason, each power receiving device 30 needs to be able to receive a wide range of voltages, for example, from 30 V to 2 V, that correspond to the variation in distance. Regardless of the distance from the power supply device 40 to the power receiving device 30, the power receiving device 30 needs to convert a wide range of voltages, at least from 30 V to 2 V, using a DC/DC converter or the like, and efficiently receive power over the entire range of the wide range of voltages. However, there are no commercially available DC/DC converters that can convert a wide range of voltages with high efficiency over the entire range.

On the other hand, when the sensor device 10 incorporating the power receiving device 30 is manufactured, the location of the sensor device 10 incorporating the power receiving device 30 on which machine tool in the factory it will be installed, the location of the power supply device 40 in the factory, and ultimately the distance from the power supply device 40 to the power receiving device 30 are all basically undetermined. For this reason, it is not realistic to uniquely determine the voltage value of the electricity input to the power receiving device 30 in advance and incorporate a DC/DC converter corresponding to the voltage value into the power receiving device 30.

In view of the above circumstances, this embodiment aims to realize a power receiving device 30 that can efficiently receive power over the entire range of voltages supplied from the power supply device 40.

4. Configuration of a sensor device with a built-in power receiving device

Figure 3 shows the configuration of a sensor device that incorporates a power receiving device.

The sensor device 10 has a power receiving device 30 and a sensor element 110.

The sensor element 110 has a sensor body for detecting vibration, acceleration, rotation speed, and/or temperature of a machine tool (e.g., spindle 81 in FIG. 2). The sensor element 110 further has a memory device for temporarily storing the detected value, a terminal (not shown) for connecting to the child tag 20 (FIG. 2), etc.

The power receiving device 30 stores the electricity wirelessly supplied by the power supply device 40 and supplies it to the sensor element 110. The power receiving device 30 has a power receiving antenna 310, an input switching unit 320, a converter array 330, and a power storage device 340.

The power receiving antenna 310 wirelessly receives electricity wirelessly supplied by the power supply device 40. The power receiving antenna 310 is, for example, a planar metal plate with an enamel wire radially arranged from the center of the surface and attached to the surface.

The electricity wirelessly received by the receiving antenna 310 is input to the input switching unit 320.

The input switching unit 320 has a plurality of different Zener diodes 321, 322, 323.... The plurality of different Zener diodes 321, 322, 323... are connected in parallel to the power receiving antenna 310. The Zener diodes 321, 322, 323... are also called constant voltage diodes, and are diodes that extract only the desired voltage (Zener voltage). The voltages extracted by the Zener diodes 321, 322, 323... are all different. For example, the Zener diode 321 extracts a voltage of 0.5V or more and less than 2V from the voltage input from the power receiving antenna 310. The Zener diode 322 extracts a voltage of 2V or more and less than 5V from the voltage input from the power receiving antenna 310. The Zener diode 323 extracts a voltage of 5V or more and less than 10V from the voltage input from the power receiving antenna 310. In addition to Zener diodes 321, 322, and 323, input switching unit 320 has one or more other Zener diodes (not shown). The one or more other Zener diodes (not shown) extract a voltage of, for example, up to about 40 V.

The maximum value of the voltage extracted by the multiple different Zener diodes 321, 322, 323... is the value of the voltage received from the power supply device 40 when the distance between the power supply device 40 and the power receiving device 30 is at its minimum. The minimum value of the voltage extracted by the multiple different Zener diodes 321, 322, 323... is the value of the voltage received from the power supply device 40 when the distance between the power supply device 40 and the power receiving device 30 is at its maximum. The multiple different Zener diodes 321, 322, 323... are capable of seamlessly extracting the entire range of voltages, from the maximum voltage to the minimum voltage.

The voltages extracted by the multiple different Zener diodes 321, 322, 323, etc. included in the input switching unit 320 are input to the converter array 330.

Converter array 330 has multiple different converters 331, 332, 333... Multiple different converters 331, 332, 333... Multiple different converters 331, 332, 333... convert different voltages into a constant voltage (a voltage suitable for storage battery 340). For example, converter 331 is a step-up DC/DC converter that converts a voltage of 0.5V or more and less than 2V to 5V. Converter 332 is a step-up/step-down DC/DC converter that converts a voltage of 2V or more and less than 5V to 5V. Converter 333 is a step-up/step-down DC/DC converter that converts a voltage of 5V or more and less than 10V to 5V. Converter array 330 has one or more other DC/DC converters in addition to converters 331, 332, 333. The other one or more DC/DC converters (not shown) are, for example, step-down DC/DC converters that convert a voltage of up to about 40V to 5V.

The maximum value of the voltage converted by the multiple different converters 331, 332, 333... is the value of the voltage received from the power supply device 40 when the distance between the power supply device 40 and the power receiving device 30 is at its minimum. The minimum value of the voltage converted by the multiple different converters 331, 332, 333... is the value of the voltage received from the power supply device 40 when the distance between the power supply device 40 and the power receiving device 30 is at its maximum. The multiple different converters 331, 332, 333... are capable of seamlessly converting the entire range of voltages, from the maximum voltage to the minimum voltage, into a constant voltage.

A plurality of different converters 331, 332, 333... are connected in a one-to-one relationship to a plurality of different Zener diodes 321, 322, 323... Specifically, a converter 331 that converts a voltage of 0.5V or more and less than 2V to 5V is connected to the Zener diode 321 that extracts a voltage of 0.5V or more and less than 2V. A converter 332 that converts a voltage of 2V or more and less than 5V to 5V is connected to the Zener diode 322 that extracts a voltage of 2V or more and less than 5V. A converter 332 that converts a voltage of 5V or more and less than 10V to 5V is connected to the Zener diode 323 that extracts a voltage of 5V or more and less than 10V. In this way, each of the Zener diodes 321, 322, 323... inputs the voltage input from the power receiving antenna 310 to each of the converters 331, 332, 333... that can convert that voltage.

For example, suppose a voltage of 1V is input from the power receiving antenna 310 to the input switching unit 320. In this case, of the multiple different Zener diodes 321, 322, 323, etc. included in the input switching unit 320, only the Zener diode 321, which is capable of extracting a voltage of 0.5V or more and less than 2V, extracts a voltage of 1V. The Zener diode 321 inputs the extracted 1V voltage to the converter 331. The converter 331 converts the input voltage of 1V to 5V and outputs it. Due to the configuration of the input switching unit 320 and the converter array 330, the voltage output from the converter array 330 is constant at 5V, regardless of the value of the voltage received by the power receiving antenna 310.

The electricity converted to a constant voltage (5V in this example) by the multiple different converters 331, 332, 333, etc. included in the converter array 330 is input to the capacitor 340.

The capacitor 340 is typically a capacitor. The capacitor 340 stores electricity at a constant voltage (5 V in this example) output by multiple different converters 331, 332, 333, etc. included in the converter array 330. The electricity stored in the capacitor 340 is supplied to the sensor element 110.

5. Conclusion

According to this embodiment, the input switching unit 320 switches the voltage input to multiple different converters 331, 332, 333... that convert different voltage values into a constant voltage. As a result, the multiple different converters 331, 332, 333... can convert a wide range of voltages into a constant voltage (a voltage suitable for the storage battery 340) with high efficiency over the entire range, regardless of the value of the received voltage, which varies depending on the distance from the power supply device 40 to the power receiving device 30.

According to this embodiment, the input switching unit 320 has a plurality of different Zener diodes 321, 322, 323.... The plurality of different Zener diodes 321, 322, 323... input a voltage that can be converted by each converter 331, 332, 333... to which each Zener diode 321, 322, 323... is connected. As a result, one Zener diode 321, 322, 323... extracts a voltage according to the value of the receiving voltage that varies depending on the distance from the power supply device 40 to the power receiving device 30, and inputs the voltage to one converter 331, 332, 333.... As a result, the Zener diodes 321, 322, 323... can automatically input a voltage to one converter 331, 332, 333... without the need for information processing to determine one converter 331, 332, 333... to which the voltage should be input. This means no power is required for information processing.

Although the embodiments and variations of the present technology have been described above, the present technology is not limited to the above-described embodiments, and various modifications can of course be made without departing from the spirit of the present technology.

REFERENCE SIGNS LIST 1 Power supply system 10 Sensor device 110 Sensor element 30 Power receiving device 310 Power receiving antenna 320 Input switching unit 321, 322, 323 Zener diode 330 Converter array 331, 332, 333 Converter 340 Power storage device 40 Power supply device

Claims (9)

a power receiving antenna that wirelessly receives electricity wirelessly supplied from a power supply device;
A number of different converters, each of which converts a different voltage to a constant voltage;
an input switching unit that inputs the electricity received by the power receiving antenna to a converter capable of converting a voltage of the electricity;
Equipped with
the input switching unit includes a plurality of different Zener diodes respectively connected to the plurality of different converters;
The plurality of different Zener diodes each input a voltage that the converter can convert to a corresponding converter to which the Zener diode is connected.
Powered device. The power receiving device according to claim 1 ,
The power receiving device further comprises a storage device that stores the electricity of the constant voltage output from the plurality of different converters. The power receiving device according to claim 2 ,
The power receiving device, wherein the storage device is a capacitor. a power receiving antenna for receiving electricity wirelessly supplied from a power supply device;
A number of different converters, each of which converts a different voltage to a constant voltage;
an input switching unit that inputs the electricity received by the power receiving antenna to a converter capable of converting a voltage of the electricity;
a storage battery that stores electricity of the constant voltage output from the plurality of different converters;
having
the input switching unit includes a plurality of different Zener diodes respectively connected to the plurality of different converters;
The plurality of different Zener diodes each input a voltage that the converter can convert to a corresponding converter to which the Zener diode is connected.
A power receiving device;
a sensor element to which the electricity stored in the capacitor is supplied;
A sensor device comprising: The sensor device according to claim 4 ,
The sensor device is installed in a machine tool,
The sensor element is a sensor device that detects vibration, acceleration, rotation speed and/or temperature of the machine tool. A power supply device;
a power receiving antenna for receiving electricity wirelessly supplied from the power supply device;
A number of different converters, each of which converts a different voltage to a constant voltage;
an input switching unit that inputs the electricity received by the power receiving antenna to a converter capable of converting a voltage of the electricity;
having
the input switching unit includes a plurality of different Zener diodes respectively connected to the plurality of different converters;
The plurality of different Zener diodes each input a voltage that the converter can convert to a corresponding converter to which the Zener diode is connected.
A power receiving device;
A power supply system comprising: The power supply system according to claim 6 ,
The power receiving device is
The power supply system further includes a storage device that stores electricity of the constant voltage output from the plurality of different converters,
A power supply system included in a sensor device having a sensor element to which the electricity stored in the capacitor is supplied. The power supply system according to claim 6 or 7 ,
A power supply system comprising a plurality of the power receiving devices. The power receiving antenna receives the electricity wirelessly supplied by the power supply device,
an input switching unit inputs the voltage of the electricity received by the power receiving antenna to a converter capable of converting the voltage among a plurality of different converters that convert different voltages into a constant voltage;
The converter converts the input voltage into the constant voltage.
A power receiving method, comprising:
the input switching unit includes a plurality of different Zener diodes respectively connected to the plurality of different converters;
The plurality of different Zener diodes each input a voltage that the converter can convert to a corresponding converter to which the Zener diode is connected.
How to receive power.

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