JP5639095B2 - Wireless communication system for rotating body - Google Patents

Description

  The present invention relates to a wireless communication system for a rotating body for performing wireless communication between the rotating body and a support portion thereof.

  As a conventional wireless communication system for a rotating body, wireless communication is performed between a fixed loop antenna attached to a support portion that supports a stator of a motor and a rotary loop antenna attached to a rotor of the motor. It is known (see, for example, Patent Document 1).

JP 2009-11054 A (paragraphs [0019] to [0024], FIG. 1)

  However, in the above-described conventional wireless communication system for a rotating body, depending on the rotational position of the rotor, the position of the rotation-side loop antenna may deviate from the reception area of the radio wave from the fixed-side loop antenna, and wireless communication cannot be performed. was there. That is, in the conventional wireless communication system for a rotating body, it is impossible to perform stable wireless communication at all the rotational positions of the rotating body.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a wireless communication system for a rotating body capable of performing stable wireless communication at all rotational positions of the rotating body.

  The wireless communication system for a rotating body according to the invention of claim 1 made to achieve the above object is fixed to a support portion (80) that rotatably supports the rotating body (60), and the rotating body (60). A fixed-side radio device (10) having a fixed-side loop antenna (11) disposed opposite to one end surface (60M) of the sensor, and a sensor that is attached to the rotating body (60) and detects temperature, magnetic flux intensity, and other physical quantities (40) and a rotation-side loop antenna (23, 230) fixed to one end face (60M) of the rotating body (60), and a sensor (40) according to a radio wave from the fixed-side radio (10). ) In the wireless communication system for a rotating body (100) including the transponder (20) that returns the detection data of the physical quantity detected in (), the fixed-side loop antenna (11) at all rotational positions of the rotating body (60). Rotation side A plurality of rotation-side loop antennas (23, 230) are arranged in the circumferential direction of one end surface (60M) of the rotating body (60) so that radio waves can be transmitted / received to / from the loop antenna (23, 230). It has the characteristics in that place.

  A second aspect of the present invention is the wireless communication system for a rotating body (100) according to the first aspect, wherein a plurality of twin rotation-side loop antennas are formed by connecting both terminals of a plurality of pairs of rotation-side loop antennas (230) to each other. (231, 232), and the twin rotating side loop antennas (231, 232) are arranged in the circumferential direction of one end face (60M) of the rotating body (60) and adjacent one and the other twin rotating side It is characterized in that the rotation side loop antennas (230) are arranged in an overlapping manner between the loop antennas (231, 232).

  According to a third aspect of the present invention, in the wireless communication system for a rotating body (100) according to the first aspect, a plurality of rotation-side loop antennas (23) are connected to a pair of input / output circuits (28) of the transponder (20). It is characterized by being connected in series between output terminals.

  According to a fourth aspect of the present invention, in the wireless communication system for a rotating body (100) according to any one of the first to third aspects, the magnetic material sheet (32) is provided on one end face (60M) of the rotating body (60). ), And the rotation side loop antenna (23, 230) is laid.

  According to a fifth aspect of the present invention, in the wireless communication system for a rotating body (100) according to any one of the first to fourth aspects, the rotating body (60) is an outer rotor of the in-wheel motor (50). 60), the support portion (80) is a vehicle body (80) that supports the inner stator (51) of the in-wheel motor (50), and the sensor (40) is fixed to the outer rotor (60). The temperature sensor (40) for detecting the temperature of the magnet (63) or the magnetic sensor (40) for detecting the magnetic flux intensity of the magnet (63), which is a substitute value for the temperature, is characterized.

  According to a sixth aspect of the present invention, in the wireless communication system for a rotating body (100) according to the fifth aspect, the outer rotor (60) includes a cylindrical rotor body (69) and a rotor body (69). A plurality of magnet accommodation chambers (62) formed in the middle between the peripheral surface and the outer peripheral surface, opened to one end surface (60M) of the rotor body (69) and containing the magnet (63) therein, and the rotor body (69 ) And an annular lid (65) which is fixed to be overlapped with one end surface of the magnet housing chamber (62) and closes the opening of the magnet housing chamber (62), and has a plurality of rotation-side loop antennas (23, 23) on the outer surface of the annular lid (65). 230) is fixed.

  According to a seventh aspect of the present invention, in the wireless communication system for a rotating body (100) according to the fifth or sixth aspect, the transponder (20) is an RFID tag (20) attached to the outer surface of the annular lid (65). On the other hand, the fixed side wireless device (10) is characterized in that it is an RFID reader (10).

  According to an eighth aspect of the present invention, in the rotating body (60) wireless communication system according to the seventh aspect, the RFID tag (20) and the magnet are inserted through a connection hole (65A) formed through the annular lid (65). (63) is provided with a projecting shaft body (43) that is in a stretched state, and the sensor (40) is fixed to the tip of the projecting shaft body (43).

  According to a ninth aspect of the present invention, in the wireless communication system for a rotating body (100) according to the seventh or eighth aspect, the protective resin sheet (35) covering the RFID tag (20) is fixed to the annular lid (65). It is characterized by the provision.

  According to a tenth aspect of the present invention, in the wireless communication system for a rotating body (100) according to any one of the fifth to ninth aspects, the magnetic sheet (32) is interposed on the outer surface of the annular lid (65). It is characterized in that the rotating loop antenna (23, 230) is laid.

[Invention of Claim 1]
According to the wireless communication system for a rotating body (100) according to the invention of claim 1, the magnetic flux of the radio wave output from the fixed side loop antenna (11) provided in the fixed side wireless device (10) Regardless of the rotational position of 60), it passes through any one of the plurality of rotation-side loop antennas (23, 230) fixed to one end face (60M) of the rotating body (60). Stable wireless communication can be performed at the rotational position.

[Invention of claim 2]
According to the invention of claim 2, when the magnetic flux of the radio wave output from the fixed side loop antenna (11) penetrates any one of the plurality of rotation side loop antennas (230), the rotation side loop arranged in an overlapping manner. The antennas (230) are inductively coupled to each other one after another, and the transponder (20) is routed through twin loop antennas (231, 232) adjacent in the circumferential direction of one end face (60M) of the rotating body (60). Since an electric signal is input to the modulation / demodulation circuit (28), stable wireless communication can be performed at all the rotational positions of the rotating body (60).

[Invention of claim 3]
According to the invention of claim 3, since the plurality of rotation-side loop antennas (23) are connected in series between the pair of input / output terminals in the modulation / demodulation circuit (28) of the transponder (20), 60), stable wireless communication can be performed at all rotational positions.

[Invention of claim 4]
According to the invention of claim 4, since the magnetic material sheet (32) forms a part of the magnetic path penetrating the rotation side loop antenna (23, 230), generation of eddy current can be prevented and wireless communication can be performed. Can be performed stably.

[Invention of claim 5]
When the in-wheel motor (50) is operated in a high load state, the temperature of the magnet (63) may increase rapidly and the magnetic flux intensity may decrease accordingly. According to the invention of claim 5, the magnet (63) ) Or the magnetic flux intensity of the magnet (63), which is a substitute value thereof, can always be monitored, so that it is possible to prevent the magnet (63) from exceeding a predetermined temperature and becoming hot.

[Inventions of Claims 6 and 7]
According to the invention of claim 6, a plurality of rotation side loop antennas (23, 230) using the outer surface of the annular lid (65) for retaining the magnet (63) housed in the magnet housing room (62). Is fixed, and the fixed side loop antenna (11) is disposed opposite to the outer surface of the annular lid (65), so that the detection data of the temperature sensor (40) or the magnetic sensor (40) is transmitted to the fixed side radio (10). Can be read. Here, the RFID tag (20) and the RFID reader (10) can be used as the transponder (20) and the fixed-side radio (10), respectively (invention of claim 7).

[Invention of Claim 8]
According to the invention of claim 8, since the sensor (40) can be pressed against the magnet (63) by the tension shaft (43), the sensor (40) and the magnet (63) are not fixed with an adhesive or the like. ) Can be maintained.

[Invention of claim 9]
According to the invention of claim 9, damage of the RFID tag (20) can be prevented by the protective resin sheet (35).

[Invention of Claim 10]
According to the invention of claim 10, since the magnetic material sheet (32) forms a part of the magnetic path penetrating the rotation side loop antenna (23, 230), it is possible to prevent the generation of eddy current and wirelessly. Communication can be performed stably.

1 is a side sectional view of a motor-integrated drive wheel equipped with a wireless communication system for rotating bodies according to a first embodiment of the present invention. Top view of the rotor body Perspective view of rotor cap Top view of RFID tag Cross-sectional view of base material in RFID tag Sectional view of the outer rotor cut at the connection between the RFID tag and the sensor Sectional view of the outer rotor cut at the connection between the RFID tag and the sensor Sectional view of the outer rotor cut at the connection between the RFID tag and the sensor Sectional view of the outer rotor cut at the connection between the RFID tag and the sensor Block diagram of wireless communication system for rotating body The top view of the RFID tag which concerns on 2nd Embodiment (A) Plan view of the first twin loop antenna, (B) Plan view of the second twin loop antenna Cross-sectional view of RFID tag and protective resin sheet A top view of an RFID tag including a rotation-side loop antenna according to a modification.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a drive wheel 90 with a built-in motor provided in an electric vehicle. The drive wheel 90 with a built-in motor is supported by the vehicle main body 80 via a suspension device (not shown), and includes a wheel 70 and an outer rotor type in-wheel motor 50 disposed inside the wheel 70. The wheel 70 includes a tire 71 and a tire wheel 72, and the tire wheel 72 includes a rim 73 on which the tire 71 is mounted and a disk 74 that projects from the inner periphery of the rim 73.

  The in-wheel motor 50 includes a cylindrical inner stator 51 and a cylindrical outer rotor 60 disposed outside the inner stator 51.

  The inner stator 51 includes a cylindrical stator core 52 made of a silicon steel plate and a stator coil 53 wound around the stator core 52, and is fixed to the outside of a wheel support portion 81 having a cylindrical structure. The wheel support portion 81 is fixed to the vehicle main body 80 via a suspension device (not shown). That is, the inner stator 51 is supported by the vehicle main body 80 via the wheel support portion 81 and the suspension device, and the vehicle main body 80 corresponds to the “support portion” of the present invention.

  A plurality of permanent magnets 63 are embedded between the inner peripheral surface and the outer peripheral surface of the outer rotor 60. The outer rotor 60 has a bottomed cylindrical rotor body 69 (see FIG. 2) and an annular rotor cap 65 (see FIG. 3) at a position near one end in the rotation axis direction (position near the vehicle body 80). It can be disassembled. The rotor cap 65 corresponds to the “annular lid” of the present invention.

  The rotor body 69 includes a cylindrical outer shell cover 64 having a bottom, and a cylindrical rotor yoke 61 is fitted and fixed to the inside thereof so as not to rotate. The outer shell cover 64 and the rotor cap 65 are made of the same nonmagnetic metal (for example, aluminum), and the outer shell cover 64 and the rotor cap 65 are connected by a plurality of bolts (not shown) penetrating through the flange portions. It is fixed integrally.

  As shown in FIG. 2, a plurality of permanent magnets 63 are embedded in a ring shape along the circumferential direction of the outer rotor 60. Specifically, the rotor yoke 61 is formed with a plurality of magnet housing chambers 62 penetrating in the axial direction, and plate-like permanent magnets 63 are inserted into the respective magnet housing chambers 62. Both end openings of the magnet housing chamber 62 are closed by the bottom wall 64S of the outer shell cover 64 and the rotor cap 65, and both end surfaces of the permanent magnets 63 are abutted against the bottom wall 64S and the rotor cap 65 to prevent the magnet housing chamber 62 from coming off. Has been.

  The outer shell cover 64 is fixed to the tire wheel 72 by a plurality of bolts 75 penetrating the bottom wall 64S and the disk 74 of the tire wheel 72. Thereby, the outer rotor 60 and the tire wheel 72 (wheel 70) can rotate integrally.

  The rotor cap 65 is supported outside the wheel support portion 81 via a bearing 76. An output shaft 66 stands from the center of the bottom wall 64S of the outer shell cover 64 toward the vehicle body 80, and the output shaft 66 extends through the inside of the stator core 52 and the wheel support portion 81. . A bearing 67 is fitted between the outer peripheral surface of the output shaft 66 and the inner peripheral surface of the wheel support portion 81. With these bearings 67 and 76, the outer rotor 60 can rotate outside the inner stator 51. The in-wheel motor 50 and the outer rotor 60 are not limited to the configuration described above.

  The RFID tag 20 and the sensor 40 are attached to the outer rotor 60 of the in-wheel motor 50, and the vehicle body 80 that supports the inner stator 51 of the in-wheel motor 50 is wirelessly connected to the RFID tag 20. An RFID reader 10 that performs communication is attached. The RFID tag 20, the RFID reader 10 and the sensor 40 constitute a rotating body wireless communication system 100 (see FIG. 10) according to the present invention.

  The sensor 40 of the present embodiment is a temperature sensor (for example, a thermistor, a resistance temperature detector, etc.) for detecting the temperature of the permanent magnet 63 provided in the outer rotor 60 and is made of a heat resistant adhesive or the like. Directly fixed to 63 (see FIGS. 6 to 8). The sensor 40 may be a magnetic sensor (for example, a Hall element, a magnetic impedance element, or the like) that detects magnetic flux intensity that is a substitute value of temperature. Further, the sensor 40 may be fixed to only one permanent magnet 63 or may be fixed to a plurality of arbitrary permanent magnets 63.

  As shown in FIG. 10, the RFID reader 10 includes a fixed loop antenna 11, a wave transmission / reception unit 12, and a control unit 13. The control unit 13 usually outputs a signal including a data transmission command as a radio wave by the transmission / reception unit 12 and outputs it from the fixed loop antenna 11. In response to this, the radio wave output from the RFID tag 20 is received by the fixed loop antenna 11, and the information included in the radio wave is extracted and acquired by the wave transmitting / receiving unit 12. The RFID reader 10 can also communicate with a host device 16 (for example, ECU) provided in the electric vehicle.

  In the RFID reader 10, a main body 15 (see FIG. 1) in which the wave transmitting / receiving unit 12 and the control unit 13 are built is fixed in the vehicle main body 80 at a position near the motor built-in driving wheel 90. The fixed-side loop antenna 11 is formed by winding a conductive wire a plurality of times in a loop shape, and is disposed so as to face the loop surface in parallel with the one end surface 60M of the outer rotor 60. The RFID reader 10 may be a so-called “antenna integrated type” in which the fixed loop antenna 11 is built in the main body 15, or the main body 15 and the fixed loop antenna 11 are connected to the antenna cable as shown in FIG. 1. The so-called “antenna-separated type” may be connected to each other.

  On the other hand, as shown in FIG. 3, a sheet-like RFID tag 20 is attached to one end surface 60M (rotor cap 65) of the outer rotor 60. As shown in FIG. 4, the RFID tag 20 includes a rotation-side loop antenna 23 and an IC chip 22, and the IC chip 22 includes a memory 26, a control unit 27, a modem circuit 28, a rectifying unit 29, and the like ( (See FIG. 10).

  The memory 26 is, for example, a nonvolatile memory (EEPROM), and stores detection data (temperature data) from the sensor 40.

  The rectifying unit 29 converts the AC voltage electromagnetically induced in the rotation-side loop antenna 23 by a radio wave AC magnetic field received from the RFID reader 10 into a DC voltage and applies the DC voltage to the control unit 27. As a result, the control unit 27 operates to execute a predetermined program, and information included in the radio wave received by the rotation-side loop antenna 23 is acquired through the modulation / demodulation circuit 28. When the data transmission command is included in the information acquired at this time, the control unit 27 reads the detection data (temperature data) from the sensor 40 from the memory 26. Then, information including the detection data is converted into a radio wave by the modulation / demodulation circuit 28 and output from the rotation side loop antenna 23.

  As shown in FIG. 4, the RFID tag 20 is formed by fixing an IC chip 22 and a rotation-side loop antenna 23 to a base material 21. The base material 21 is formed of an annular sheet corresponding to the shape of the one end surface 60M of the outer rotor 60, and is attached to the one end surface 60M of the outer rotor 60.

  As shown in FIG. 5, the base material 21 has a laminated structure in which a cover sheet 30, a base sheet 31, a magnetic sheet 32, and the like are stacked, and an IC chip 22 provided on the base sheet 31 and a rotation side loop. A cover sheet 30 covers the antenna 23. That is, the IC chip 22 and the rotation side loop antenna 23 are sealed by the base sheet 31 and the cover sheet 30. Further, the back surface of the magnetic material sheet 32 is an adhesive surface, and the adhesive surface is affixed to the outer rotor 60.

  The magnetic sheet 32 has a configuration in which a thin-film magnetic material having high magnetic permeability and electrical insulation is protected with a resin film. The magnetic sheet 32 is disposed between the base sheet 31 provided with the rotation side loop antenna 23 and the IC chip 22 and one end surface 60M of the outer rotor 60. In other words, the rotation-side loop antennas 23 and 23 are laid on one end surface 60M of the outer rotor 60 with the magnetic material sheet 32 interposed therebetween. The magnetic sheet 32 forms a part of a magnetic path that penetrates the rotation-side loop antenna 23 and prevents the generation of eddy currents in the vicinity of one end surface 60M of the outer rotor 60 made of a nonmagnetic metal. Therefore, radio waves can be reliably transmitted and received between the rotation side loop antenna 23 and the fixed side loop antenna 11.

  Now, the RFID tag 20 of this embodiment has a plurality of rotation-side loop antennas 23, 23, and the plurality of rotation-side loop antennas 23, 23 are connected to a pair of input / output in the modulation / demodulation circuit 28 of the IC chip 22. The terminal is connected in series between the terminals. As shown in FIG. 4, the plurality of rotation-side loop antennas 23, 23 are arranged substantially evenly in the circumferential direction of the rotor 60 (base material 21), and can be drawn with one continuous line. Is formed. Further, the interval between the rotation-side loop antennas 23 and 23 adjacent to each other in the circumferential direction of the base material 21 (rotor 60) is a receiving region R1 that can receive a radio wave from the fixed-side loop antenna 11 (shaded portion in FIG. 4). ) Is smaller than the width. In this embodiment, the loop of each rotation-side loop antenna 23 is rectangular, but it may be circular or oval, and the number of turns of the loop may be set arbitrarily. The rotation side loop antenna 23 may be formed by any of printing, winding, and etching.

  As shown in FIG. 6, a connection hole 65A is formed through the rotor cap 65, and the sensor 40 and the IC chip 22 directly fixed to the permanent magnet 63 are connected via the connection hole 65A. Yes. As a connection structure between the IC chip 22 and the sensor 40, for example, a cable connection shown in FIG. 6 and a connector connection shown in FIGS. 7 and 8 are conceivable.

  In the cable connection shown in FIG. 6, when the rotor cap 65 is overlapped and fixed on the end face of the rotor body 69, the sensor 40 and the permanent magnet 63 need to be fixed in advance. Therefore, the cable 41 is sufficiently longer than the hole length of the connection hole 65A.

  In the connector connection shown in FIG. 7, the middle portion of the cable 41 is connected by a pair of connectors 42 and 42. In this connection structure, the connection between the connectors 42 and 42 can be released at the intermediate portion of the cable 41, so that it is not necessary to remove the sensor 40 from the permanent magnet 63 when removing the rotor cap 65 from the rotor body 69.

  In the connector connection shown in FIG. 8, connectors 42 and 42 are provided at the end of the cable 41 extending from the sensor 40 and the RFID tag 20. In this connection structure, the RFID tag 20 and the sensor 40 can be connected or disconnected while the rotor cap 65 and the rotor body 69 are fixed.

  Furthermore, as shown in FIG. 9, the sensor 40 may be fixed to the tip of a projecting shaft 43 having a structure like a “contact probe (spring probe)”. The extension shaft body 43 has an expandable and narrow tube structure with a built-in spring, and an electric wire (not shown) connecting the sensor 40 and the IC chip 22 is passed through the extension shaft body 43. When the RFID tag 20 is fixed to the one end surface 60M of the outer rotor 60, the projecting shaft body 43 is stretched between the RFID tag 20 and the permanent magnet 63, and the sensor 40 is pressed against the permanent magnet 63. With such a structure, it is not necessary to fix the sensor 40 to the permanent magnet 63 before fixing the rotor body 69 and the rotor cap 65 as in the above-described three connection structures. The sensor 40 and the RFID tag 20 can be retrofitted to the rotor 60. Therefore, the assembly work of the outer rotor 60 is simplified as compared with the above-described three connection structures. Further, the contact state between the sensor 40 and the permanent magnet 63 can be maintained without being fixed with an adhesive or the like. In addition, the above-described connection structure is an example, and the present invention is not limited thereto, and other connection structures may be employed.

  The above is the configuration of the present embodiment, and the operation of the present embodiment will be described below. When the start switch of the electric vehicle is turned on, the host device 16 is activated and outputs a data request command to the RFID reader 10 at a predetermined cycle. Then, the RFID reader 10 converts the information including the data transmission command into a radio wave by the transmission / reception unit 12 (on a carrier wave) and outputs it from the fixed loop antenna 11. This radio wave reaches the receiving region R1 (the hatched portion in FIGS. 3 and 4) that is the portion facing the fixed-side loop antenna 11 and the vicinity thereof in the one end surface 60M of the outer rotor 60.

  The RFID tag 20 provided on the one end surface 60M of the outer rotor 60 receives the radio wave output from the RFID reader 10 by the rotation-side loop antenna 23. Further, the AC voltage electromagnetically induced in the rotation-side loop antenna 23 by the AC magnetic field of the radio wave from the fixed-side loop antenna 11 is converted into a DC voltage by the rectifying unit 29 and applied to the control unit 27. As a result, the control unit 27 operates, and the control unit 27 acquires information included in the radio wave received by the rotation-side loop antenna 23 through the modulation / demodulation circuit 28.

  If the information acquired at this time includes a “data transmission command”, the control unit 27 reads the detection data (temperature data) from the sensor 40 from the memory 26 and converts the information including the detection data into a modulation / demodulation circuit. To 28. The modem circuit 28 converts the information including the detection data into a radio wave (on a carrier wave) and outputs it from the rotation side loop antenna 23. The information including the detection data is used to identify the ID information of the RFID tag 20, that is, the in-wheel motor 50 among the plurality of in-wheel motors 50 provided in the electric vehicle. Information may be included.

  The radio wave output from the RFID tag 20 is received by the fixed loop antenna 11 of the RFID reader 10. And the transmission / reception part 12 decodes the information contained in a radio wave, and the control part 13 acquires the information. Further, the control unit 13 outputs the acquired information to the higher-level device 16.

  The host device 16 determines whether the temperature data acquired from the RFID tag 20 is normal. And when it determines with it being abnormal, ie, when the temperature of the permanent magnet 63 becomes higher than preset temperature, the command (for example, instruction | command of an electric current limitation or forced cooling) for temperature rise suppression or cooling is given. Output.

  As described above, according to the wireless communication system for a rotating body 100 of the present embodiment, the plurality of rotation side loop antennas 23 and 23 are arranged side by side in the circumferential direction of the one end surface 60M of the outer rotor 60, and all the rotation side loops are arranged. The antennas 23 and 23 are connected in series between a pair of input / output terminals in the modem circuit 28. The radio wave magnetic flux output from the fixed-side loop antenna 11 of the RFID reader 10 passes through one of the plurality of rotation-side loop antennas 23, 23 regardless of the rotational position of the outer rotor 60. Thus, stable wireless communication can be performed at all rotational positions of the outer rotor 60. Specifically, the detection data of the temperature of the permanent magnet 63 by the sensor 40 can be read into the RFID reader 10 at all rotational positions of the outer rotor 60.

  In addition, according to the present embodiment, since the sensor 40 is directly fixed to the permanent magnet 63, even when the temperature of the permanent magnet 63 is rapidly increased by driving the in-wheel motor 50 in a high load state, the response is high. Thus, the temperature of the permanent magnet 63 can be detected. Thereby, the abnormal heat generation of the permanent magnet 63 and the accompanying decrease in the magnetic flux intensity can be prevented.

[Second Embodiment]
In the first embodiment, the plurality of rotation-side loop antennas 23 and 23 arranged side by side in the circumferential direction of the outer rotor 60 are formed in a single stroke. On the other hand, in the present embodiment, a plurality of twin loop antennas 231 and 232 in which a pair of rotation-side loop antennas 230 and 230 are formed in a single stroke are arranged side by side in the circumferential direction of the outer rotor 60 and are arranged in the circumferential direction. The rotation side loop antennas 230 of the adjacent twin loop antennas 231 and 232 are overlapped with each other so that the overlapping rotation side loop antennas 230 and 230 can be coupled by electromagnetic induction.

  As shown in FIG. 12A, the first twin loop antenna 231 is configured such that both terminals of a pair of rotation-side loop antennas 230 and 230 having a rectangular loop shape are connected to each other by a pair of connecting lines 230B and 230B. The IC chip 22 (specifically, the input / output terminal of the modem circuit 28) is connected to one connecting line 230B. The distance between the rotation-side loop antennas 230 and 230 in the first twin loop antenna 231 is smaller than the width of the reception region R1 that can receive the radio wave from the fixed-side loop antenna 11.

  As shown in FIG. 12B, the second twin loop antenna 232 is configured such that both terminals of a pair of rotation-side loop antennas 230 and 230 having a rectangular loop shape are connected to each other by a pair of connecting lines 230B and 230B. It differs from the first twin loop antenna 231 only in that it has a connected structure and is not connected to the IC chip 22.

  In the RFID tag 20 of the present embodiment, as shown in FIG. 11, a plurality of second twin loops are directed from the first twin loop antenna 231 toward both sides of the outer rotor 60 (base material 21) in the circumferential direction. Antennas 232 are arranged in a chain. Specifically, as shown in FIG. 11, one rotation-side loop antenna 230 included in the second twin loop antenna 232 overlaps with a pair of rotation-side loop antennas 230 and 230 included in the first twin loop antenna 231. One rotation-side loop antenna 230 of another second twin-loop antenna 232 is placed on the other rotation-side loop antenna 230 of the second twin-loop antenna 232, and so on. The second twin loop antenna 232 is connected so as to move away from the first twin loop antenna 231 while overlapping one rotation side loop antenna 230. In addition, the second twin loop antennas 232 and 232 of both terminals remote from the first twin loop antenna 231 are arranged at a predetermined interval in the circumferential direction of the outer rotor 60, and the interval is also the reception wave. It is smaller than the width of the region R1.

  Here, the base material 21 of the present embodiment has a structure in which two base sheets 31, 31 are stacked between a magnetic sheet 32 and a cover sheet 30. Of the two base sheets 31, 31, the first twin loop antenna 231 and about half of the second twin loop antennas 232 are provided on the base sheet 31 on the cover sheet 30 side (the front side in FIG. 11). Is provided. The first twin loop antenna 231 and the second twin loop antenna 232 are arranged at a substantially constant interval in the circumferential direction of the base material 21. On the other hand, about half of the remaining second twin loop antennas 232 are provided on the base sheet 31 on the magnetic material sheet 32 side (the back side in FIG. 11), and these second twin loop antennas 232 are also based on the base sheet 31. The material 21 is arranged at a substantially constant interval in the circumferential direction. The two base sheets 31 and 31, the magnetic sheet 32, and the cover sheet 30 are laminated to constitute the RFID tag 20 (see FIG. 11) of the present embodiment. Since other configurations are the same as those in the first embodiment, the same reference numerals are given to the same configurations, and duplicate descriptions are omitted.

  According to the present embodiment, the magnetic wave magnetic flux output from the fixed-side loop antenna 11 is a plurality of rotation-side loop antennas 230 fixed to the one end surface 60 </ b> M of the outer rotor 60 regardless of the rotational position of the outer rotor 60. It penetrates either. As a result, the rotation side loop antennas 230 arranged in an overlapping manner are successively inductively coupled in a chain, and the first and second twin loop antennas 231 and 232 adjacent in the circumferential direction of the one end surface 60M of the outer rotor 60 are coupled. The electric signal is input to the modulation / demodulation circuit 28 via. This embodiment also has the same effect as the first embodiment.

[Other Embodiments]
The present invention is not limited to the above-described embodiment. For example, the embodiments described below are also included in the technical scope of the present invention, and various other than the following can be made without departing from the scope of the invention. It can be changed and implemented.

  (1) In the above embodiment, the rotor of a rotating machine (motor) is illustrated as an example of the “rotating body” according to the present invention. However, a rotating body other than the rotor, for example, a tire of a vehicle, a tire wheel, etc. is “rotated”. As the “body”, the wireless communication system 100 for a rotating body of the present invention may be applied.

  (2) In the above-described embodiment, an example in which the present invention is applied to the in-wheel motor 50 used as a drive source of the vehicle has been described. However, vehicle motors other than the in-wheel motor 50, industrial motors, home appliance motors, and the like Moreover, you may apply the radio | wireless communications system 100 for rotary bodies of this invention. Moreover, you may apply the radio | wireless communications system for rotary bodies of this invention to a generator.

  (3) In the above embodiment, the outer rotor type rotating machine (motor) is illustrated, but the rotating body wireless communication system 100 of the present invention may be applied to the inner rotor type rotating machine (motor).

  (4) In the above embodiment, the sensor 40 is fixed to the surface of the permanent magnet 63 of the outer rotor 60, but the sensor 40 may be embedded in the permanent magnet 63. Further, the sensor 40 may be embedded in the rotor yoke 61 or fixed to the outer surface of the outer rotor 60.

  (5) In the above embodiment, the temperature sensor and the magnetic sensor are exemplified as an example of the sensor according to the present invention. However, a sensor for detecting other physical quantities other than the temperature and the magnetic flux intensity, for example, an acceleration sensor, a pressure sensor, and a vibration sensor. Alternatively, a strain sensor or the like may be used.

  (6) In the above embodiment, the “passive type” RFID tag 20 that generates electric power by receiving radio waves from the RFID reader 10 has been exemplified, but the RFID tag 20 is used for charging the generated electric power. A so-called “semi-passive” RFID tag having a power storage unit or a so-called “active” RFID tag having a built-in power supply may be used.

  (7) In the above embodiment, the magnetic material sheet 32 is provided on the base material 21, but instead of providing the magnetic material sheet 32, one of the base material provided with the rotation-side loop antennas 23, 230 and the outer rotor 60. An air gap (gap) may be provided between the end surface 60M.

  (8) In the said embodiment, you may make it the structure which replaced the base sheet 31 of the base material 21 with the resin-made thin plate. In that case, the base material 21 may be fixed to the one end surface 60M of the outer rotor 60 by a plurality of bolts (for example, bolts for fixing the rotor cap 65 and the rotor body 69) that penetrate the resin thin plate.

  (9) In the above embodiment, the base sheet 21 of the RFID tag 20 includes the cover sheet 30 that covers the IC chip 22 and the rotation-side loop antenna 23. However, as shown in FIG. The protective resin sheet 35 may be fixed to the rotor cap 65.

  (10) In the first embodiment, the plurality of rotation-side loop antennas 23 and 23 are formed in a single stroke, but for example, as shown in FIG. 14, the IC chip 22 (in detail, the modem circuit 28). A pair of bus bar lines 24, 24 extending in the circumferential direction of the base material 21 (outer rotor 60) from the pair of input / output terminals), and a plurality of rotation-side loop antennas 23 are provided on the bus bar lines 24, 24. Both terminals may be connected to each other.

  (11) In the above embodiment, the base material 21 has an annular shape, but may have a “C” shape in which a part of the annular ring is cut off.

10 RFID reader (fixed-side radio)
11 Fixed loop antenna 20 RFID tag (transponder)
23 Rotating Loop Antenna 32 Magnetic Sheet 40 Sensor 50 In-wheel Motor 60 Outer Rotor 62 Magnet Storage Room 63 Permanent Magnet (Magnet)
65 Rotor cap (annular lid)
69 Rotor body 80 Vehicle body (supporting part)
100 Wireless Communication System for Rotating Body 230 Rotating Loop Antenna

Claims (10)

Fixed side radio | wireless which has fixed side loop antenna (11) fixed to the support part (80) which supports a rotary body (60) rotatably, and is arrange | positioned facing one end surface (60M) of the said rotary body (60). A vessel (10);
A sensor (40) attached to the rotating body (60) for detecting temperature, magnetic flux intensity and other physical quantities;
The rotating body (60) has a rotating loop antenna (23, 230) fixed to one end surface (60M) of the rotating body (60), and is connected to the sensor (40) in response to a radio wave from the fixed wireless device (10). In the wireless communication system for a rotator (100) including the transponder (20) that returns detection data of the physical quantity detected by
The rotation-side loop is configured so that radio waves can be transmitted and received between the fixed-side loop antenna (11) and the rotation-side loop antenna (23, 230) at all rotation positions of the rotating body (60). A wireless communication system for a rotating body (100), wherein a plurality of antennas (23, 230) are arranged side by side in the circumferential direction of one end face (60M) of the rotating body (60).   A plurality of twin rotating side loop antennas (231, 232) are configured by connecting both terminals of a plurality of pairs of rotating side loop antennas (230) to each other, and the plurality of twin rotating side loop antennas (231, 232) are connected to each other. The rotating side loop antennas (230) are overlapped between the adjacent one and the other twin rotating side loop antennas (231, 232) while being arranged in the circumferential direction of one end surface (60M) of the rotating body (60). The wireless communication system (100) for a rotating body according to claim 1, wherein the wireless communication system (100) is a rotating body.   2. The rotating body according to claim 1, wherein the plurality of rotation-side loop antennas (23) are connected in series between a pair of input / output terminals in the modulation / demodulation circuit (28) of the transponder (20). A wireless communication system (100).   The rotating-side loop antenna (23, 230) is laid on one end surface (60M) of the rotating body (60) with a magnetic material sheet (32) interposed therebetween. A wireless communication system (100) for a rotating body according to claim 1. The rotating body (60) is an outer rotor (60) of an in-wheel motor (50), while the support portion (80) is a vehicle body that supports an inner stator (51) of the in-wheel motor (50). (80)
The sensor (40) is a temperature sensor that detects the temperature of the magnet (63) fixed to the outer rotor (60) or a magnetic sensor that detects the magnetic flux intensity of the magnet (63), which is a substitute value for the temperature. The wireless communication system (100) for a rotating body according to any one of claims 1 to 4, wherein the wireless communication system (100) is a rotating body. The outer rotor (60) is formed between a rotor body (69) having a cylindrical shape and an inner peripheral surface and an outer peripheral surface of the rotor body (69), and is formed on one end surface of the rotor body (69). A plurality of magnet accommodating chambers (62) that are open and accommodate the magnet (63) therein, and an annular shape that is fixed to overlap one end surface of the rotor body (69) and closes the opening of the magnet accommodating chamber (62) A lid (65),
The wireless communication system (100) for a rotating body according to claim 5, wherein a plurality of the rotating side loop antennas (23, 230) are fixed to an outer surface of the annular lid (65).   The transponder (20) is an RFID tag (20) attached to the outer surface of the annular lid (65), while the fixed-side radio (10) is an RFID reader (10). The wireless communication system (100) for a rotating body according to claim 5 or 6.   A tension shaft body (43) is inserted between the RFID tag (20) and the magnet (63) through a connection hole (65A) penetratingly formed in the annular lid body (65). The wireless communication system (100) for a rotating body according to claim 7, wherein the sensor (40) is fixed to a tip of the projecting shaft body (43).   The wireless communication system for a rotating body (100) according to claim 7 or 8, further comprising a protective resin sheet (35) covering the RFID tag (20) fixed to the annular lid (65). .   The rotary loop antenna (23, 230) is laid on the outer surface of the annular lid (65) with a magnetic sheet (32) interposed therebetween. A wireless communication system for a rotating body (100) according to claim 1.

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