JP2019179490A - Rotating device - Google Patents

Abstract

To provide a rotating device capable of keeping power consumption down.SOLUTION: A rotating device including a first component and a second component that relatively rotate centering around a rotation axis includes: a power generation unit for generating power on the basis of relative rotation between the first component and the second component; a power storage unit capable of charging and discharging charged by power generated by the power generation unit; a sensor; a control unit to which power stored in the power storage unit and data detected by the sensor are supplied; and a mode regulation circuit. Operation modes of the control unit include a normal mode and a sleep mode in which power consumption per unit time is smaller than the normal mode. The mode regulation circuit regulates transition from the sleep mode to the normal mode on the basis of an interval of operation mode switching.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a rotating device.

  Patent Document 1 and Patent Document 2 describe a sensor-equipped bearing that detects various physical quantities around the bearing with a sensor and wirelessly transmits detection information to a receiving device.

JP 2003-307435 A JP 2016-130577 A

  In the sensor-equipped bearing, the power generated by the power generation unit is supplied to the sensor and the communication circuit. If the power supplied to the sensor and the communication circuit is insufficient, the sensor and the communication circuit may operate abnormally or stop at an unintended timing.

  This invention is made | formed in view of the above, Comprising: It aims at providing the rotating apparatus which can suppress power consumption low.

  A rotating device according to an aspect is a rotating device having a first component and a second component that rotate relatively around a rotation axis, and is based on relative rotation between the first component and the second component. A power generation unit that generates power, a chargeable / dischargeable power storage unit that is charged by the power generated by the power generation unit, a sensor, power stored in the power storage unit, and data detected by the sensor An operation mode of the control unit, the operation mode of the control unit includes a normal mode and a sleep mode in which power consumption per unit time is lower than that of the normal mode. The restriction circuit restricts the transition from the sleep mode to the normal mode based on the interval between the operation modes.

  According to this, the control unit can keep power consumption low by maintaining the sleep mode when power supply is unstable. Thereby, the power storage unit can recover the voltage and can stabilize the supply of power to the control unit.

  As a desirable mode, the sensor transmits a first signal to the control unit under a preset condition, and the sleep mode is a first sleep mode that shifts to the normal mode when the control unit receives the first signal. And a second sleep mode that does not shift to the normal mode even when the control unit receives the first signal, and the mode regulation circuit is based on an interval of switching of the operation mode. One of the first sleep mode and the second sleep mode is selected.

  According to this, even when the control unit is in the sleep mode, when the data detected by the sensor satisfies a preset condition (for example, when the sensor detects abnormal data), the control unit shifts to the normal mode and stores the abnormal data. Can be recorded and sent externally. Thereby, the rotating device can keep power consumption of the control unit low by the sleep mode, and can not overlook abnormal data even when the control unit is in the sleep mode.

  As a desirable mode, a counter circuit for detecting an interval of timing at which the operation mode is switched is further provided. According to this, the rotating device can grasp the power supply state based on the count value of the counter circuit.

  As a desirable mode, the battery pack further includes a voltage monitoring unit that monitors the voltage of the power storage unit, and the voltage monitoring unit transmits a second signal to the control unit when the voltage of the power storage unit falls below a first threshold, The voltage monitoring unit transmits a third signal to the control unit when the voltage of the power storage unit becomes equal to or higher than a second threshold value higher than the first threshold value, and the control unit in the normal mode receives the second signal. The control unit in the normal mode shifts to the sleep mode, and when the control unit in the sleep mode receives the third signal, the control unit in the sleep mode shifts to the normal mode.

  According to this, the control unit can shift from the normal mode to the sleep mode before power becomes insufficient. Thereby, the rotating device can prevent the control unit from malfunctioning due to power shortage. In addition, the control unit can avoid re-initialization such as pair communication or reduce the number of executions by shifting from the normal mode to the sleep mode before the power becomes insufficient. Thereby, the rotating device can perform efficient power operation.

  As a desirable mode, the voltage monitoring unit includes a first voltage monitoring circuit that transmits the second signal to the control unit, and a second voltage monitoring circuit that transmits the third signal to the control unit. For example, if a reset IC is used for the voltage monitoring circuit, less power is consumed for voltage monitoring.

  As a desirable mode, the control unit includes a storage circuit that stores the data, and a communication circuit that transmits the data stored in the storage circuit to the outside, and the normal mode is performed by the communication circuit. The mode allows data transmission, and the sleep mode is a mode that disables transmission of the data by the communication circuit. According to this, since the rotating device can keep the power consumption of the communication circuit in the sleep mode low, it is possible to increase the efficiency of charging the power storage unit.

  As a desirable mode, the sensor has a first sensor and a second sensor whose detection target is different from that of the first sensor. According to this, the rotating device can output more useful data.

  According to the present invention, it is possible to provide a rotating device that can keep power consumption low.

FIG. 1 is a perspective view of a sensor-equipped bearing according to the present embodiment. FIG. 2 is an exploded perspective view of the sensor-equipped bearing according to the present embodiment. FIG. 3 is a cross-sectional view of the sensor-equipped bearing according to the present embodiment, including a power generation unit and a convex portion. FIG. 4 is a sectional view of the sensor-equipped bearing according to the present embodiment, including a power generation unit and a recess. FIG. 5 is a sectional view of the sensor-equipped bearing according to the present embodiment and including a sensor substrate. FIG. 6 is an explanatory diagram for explaining the relationship between the voltage of electromotive force and time in the sensor-equipped bearing of the present embodiment. FIG. 7 is a plan view of the sensor unit of the present embodiment. FIG. 8 is a perspective view of the cover of the present embodiment. FIG. 9 is a diagram illustrating an example of an output signal waveform of the angle sensor according to the present embodiment. FIG. 10 is a diagram showing a configuration example of a circuit mounted on the substrate of the sensor-equipped bearing according to the present embodiment. FIG. 11 is a graph schematically illustrating an example of a voltage change of the power storage unit of the present embodiment. FIG. 12 is a schematic diagram illustrating an example of a change in the detection value of the acceleration sensor according to the present embodiment. FIG. 13 is a schematic diagram illustrating an example of a change in the detection value of the temperature sensor of the present embodiment. FIG. 14 is a graph schematically illustrating an example of a voltage change of the power storage unit of the present embodiment. FIG. 15 is a flowchart (main routine) showing an example of an operation sequence of a circuit mounted on the sensor-equipped bearing substrate of the present embodiment. FIG. 16 is a flowchart (subroutine) showing an example of the first sleep process of the present embodiment. FIG. 17 is a flowchart (subroutine) showing an example of the second sleep process of the present embodiment. FIG. 18 is a diagram schematically showing the relationship between the operation period of the circuit mounted on the substrate of the sensor-equipped bearing of this embodiment and the power consumption of the CPU. FIG. 19 is a graph showing an example of the change over time of the rotational speed of the bearing with sensor.

  EMBODIMENT OF THE INVENTION About the form (embodiment) for inventing, it demonstrates in detail, referring drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the constituent elements described below can be appropriately combined.

  FIG. 1 is a perspective view of a sensor-equipped bearing according to the present embodiment. FIG. 2 is an exploded perspective view of the sensor-equipped bearing according to the present embodiment. FIG. 3 is a cross-sectional view of the sensor-equipped bearing according to the present embodiment, including a power generation unit and a convex portion. FIG. 4 is a sectional view of the sensor-equipped bearing according to the present embodiment, including a power generation unit and a recess. FIG. 5 is a sectional view of the sensor-equipped bearing according to the present embodiment and including a sensor substrate. The sensor-equipped bearing 1 shown in FIG. 1 includes a sensor unit 5, a tone ring 30, and a bearing body 20, as shown in FIG.

  As shown in FIGS. 3 to 5, the bearing body 20 is a rolling bearing having an outer ring 21, an inner ring 22, and rolling elements 23. The outer ring 21 and the inner ring 22 rotate relatively around the rotation axis Ax (see FIG. 1). Hereinafter, although the inner ring 22 will be described as a rotating wheel, any of the inner ring 22 and the outer ring 21 may be rotated as long as the inner ring 22 and the outer ring 21 are relatively rotated.

  The cover 10 includes an annular top plate 12 and a cylindrical side plate 11 connected to the periphery of the top plate 12. The cover 10 is formed of a magnetic material such as silicon steel plate, carbon steel (JIS standard SS400 or S45C), martensitic stainless steel (JIS standard SUS420), or ferritic stainless steel (JIS standard SUS430).

  As shown in FIG. 2, in the sensor unit 5, the plurality of power generation units 3 and the substrate 40 are attached to one surface 12 </ b> A of the top plate 12. One surface 12 </ b> A is a surface on the side facing the bearing body 20. The substrate 40 includes a power supply substrate 41 and a sensor substrate 42.

  For example, as shown in FIGS. 1 and 2, the power generation unit 3 is fixed to the top plate 12 by fastening a bolt 19 </ b> A made of a nonmagnetic material such as brass into a female screw hole formed in the top plate 12. Similarly, a bolt 19 </ b> B made of a nonmagnetic material such as brass is fastened to a female screw hole formed in the top plate 12, whereby the power supply substrate 41 and the sensor substrate 42 are fixed to the top plate 12. As shown in FIG. 1, the bolt 19 </ b> A and the bolt 19 </ b> B have a length that does not protrude from the cover 10 when attached to the cover 10.

  The tone ring 30 is provided with convex portions 31 protruding toward the outer diameter side and concave portions 32 recessed toward the inner diameter side of the convex portion 31 alternately in the circumferential direction. The tone ring 30 has a cylindrical projection 33 protruding toward the bearing body 20 on the inner peripheral side. The tone ring 30 is formed of a magnetic material such as silicon steel plate, carbon steel (JIS standard SS400 or S45C), martensitic stainless steel (JIS standard SUS420), or ferritic stainless steel (JIS standard SUS430). .

  The power generation unit 3 includes a permanent magnet 13, a yoke 14, and a coil 15. The permanent magnet 13 is fixed so as to contact the top plate 12. The yoke 14 is fixed so as to contact the permanent magnet 13. The yoke 14 may be magnetically connected to the permanent magnet 13 and may not be directly connected. The yoke 14 is made of a magnetic material such as a silicon steel plate or a NiFe alloy. The yoke 14 is desirably made of a material having a permeability equal to or higher than that of the cover 10 so that the amount of magnetic flux inside the yoke 14 is increased. When the yoke 14 is a silicon steel plate, the magnetic permeability increases, and the magnetic flux easily passes through the yoke 14.

  The coil 15 is a so-called magnet wire in which a conducting wire is wound around the yoke 14. The coils 15 of the adjacent power generation units 3 are connected in series, and wirings drawn from the coils 15 of the plurality of power generation units 3 connected in series are connected to the power supply substrate 41.

  As shown in FIG. 3, one end of the side plate 11 is fitted and fixed in a groove 21 </ b> A provided on the outer periphery of the outer ring 21. The cylindrical projection 33 is fitted and fixed in a groove 22 </ b> A provided on the inner periphery of the inner ring 22. Thereby, as shown in FIGS. 3 and 4, the inner peripheral side end surface of the yoke 14 and the inner peripheral side end surface of the top plate 12 are arranged at positions facing the convex portion 31 or the concave portion 32 of the tone ring 30. The cover 10 and the tone ring 30 can be easily attached to the bearing body 20.

  The magnetic flux Mf passes through the yoke 14, the convex portion 31 or the concave portion 32 of the tone ring 30, and the top plate 12 of the cover 10 by the magnetic field of the permanent magnet 13. For this reason, the permanent magnet 13, the yoke 14, the convex portion 31 or the concave portion 32 of the tone ring 30, and the top plate 12 of the cover 10 constitute a magnetic circuit.

  Further, as shown in FIG. 5, a magnetic body 311 having a coercive force larger than that of the tone ring 30 and showing hard magnetism is attached to a part of the outer peripheral side end face 31IF of the convex portion 31. For example, the outer peripheral side end surface 31IF of the convex portion 31 is provided with a concave portion corresponding to the shape and size of the magnetic body. The magnetic body 311 is fitted in the recess. The magnetic body 311 and the outer peripheral side end face 31IF around the magnetic body 311 are flush or substantially flush. The magnetic body 311 is, for example, a hard magnet permanent magnet. In the tone ring 30, the magnetic body 311 is attached to only one place. Each time the inner ring 22 makes one rotation (360 ° rotation) relative to the outer ring 21, the magnetic body 311 comes closest to the angle sensor 443. The angle sensor 443 includes, for example, a hall element.

  FIG. 6 is an explanatory diagram for explaining the relationship between the voltage of electromotive force and time in the sensor-equipped bearing of the present embodiment. Here, the horizontal axis of FIG. 6 is time T, and the vertical axis is the electromotive force voltage Vi. When the outer ring 21 is fixed and the inner ring 22 rotates, the tone ring 30 rotates together with the inner ring 22, and the tone ring 30 and the power generation unit 3 rotate relatively. For the yoke 14, an air gap from the inner peripheral side end surface to the outer peripheral side end surface 31IF of the convex portion 31 shown in FIG. 3, an air gap from the inner peripheral side end surface to the outer peripheral side end surface 32IF of the concave portion 32 shown in FIG. Alternate.

  As described above, the distance between the yoke 14 of the power generation unit 3 and the outer periphery of the tone ring 30 is periodically changed by the convex portion 31 and the concave portion 32 on the outer periphery of the tone ring 30. As a result, the density of the magnetic flux Mf generated in the power generation unit 3 changes. When the yoke 14 provided with the permanent magnet 13 and the tone ring 30 are close to each other, the magnetic flux Mf passing through the permanent magnet 13, the yoke 14 and the tone ring 30 is large, and the yoke 14 and the tone ring 30 are separated from each other. In this case, the magnetic flux Mf passing through the permanent magnet 13, the yoke 14, and the tone ring 30 is reduced. In accordance with the density change of the magnetic flux Mf, a voltage change occurs in the coil 15 in which a magnet wire is wound around the yoke 14.

  That is, when the yoke 14 and the outer peripheral side end face 31IF of the convex portion 31 are closest to each other, the magnetic flux Mf shown in FIG. 3 increases and the electromotive force voltage V1 shown in FIG. When the yoke 14 and the outer peripheral side end face 32IF of the recess 32 are farthest away, the magnetic flux Mf shown in FIG. 4 is reduced, and the electromotive force voltage V2 shown in FIG.

  FIG. 7 is a plan view of the sensor unit of the present embodiment. As shown in FIG. 7, a power supply unit 43 is mounted on the power supply board 41. The power supply unit 43 converts the single-phase AC power supplied from the power generation unit 3 into a DC voltage and supplies the DC voltage to the sensor substrate 42. A sensor 44, a control unit 45 having a communication circuit, and an antenna 47 are mounted on the sensor substrate 42. DC power from the power supply unit 43 is supplied to the sensor 44 and the control unit 45. The sensor 44, the control unit 45, and the antenna 47 may be configured by separate IC (Integrated Circuit) chips, or a part or all of them may be configured by one IC chip. The sensor 44 includes, for example, an acceleration sensor 441, a temperature sensor 442, and an angle sensor 443.

  FIG. 8 is a perspective view of the cover of the present embodiment. As shown in FIG. 8, the cover 10 has a through hole 12H. As shown in FIG. 1, the through hole 12H is sealed with a nonmagnetic lid 17 formed of a nonmagnetic material such as resin. As described above, the cover 10 includes the antenna 47 on the bearing body 20 side. Here, since the cover 10 has magnetism, it has an action of shielding electromagnetic waves from the antenna 47. For this reason, as shown in FIG. 7, the antenna 47 is disposed so as to overlap the nonmagnetic lid 17 in a plan view of the bearing body 20 as viewed from the direction of the rotation axis Zr. That is, the nonmagnetic lid 17 is provided on the portion of the cover 10 that faces the antenna 47. For this reason, the electromagnetic wave WV of the antenna 47 can reach the communication unit 151 via the nonmagnetic lid 17.

  As shown in FIG. 8, a plurality of recesses 18 for arranging the power generation unit 3 are provided on one surface 12 </ b> A of the top plate 12. For example, each of the plurality of recesses 18 includes a first recess 18 </ b> A for arranging the coil 15 and a second recess 18 </ b> B for arranging the permanent magnet 13. When one surface 12A is used as a reference surface, the first recess 18A is deeper than the second recess 18B.

  FIG. 9 is a diagram illustrating an example of an output signal waveform of the angle sensor according to the present embodiment. The horizontal axis in FIG. 9 is the rotation angle (deg) of the tone ring 30 with respect to the angle sensor 443, and the vertical axis is the detection voltage generated in the angle sensor 443. When the outer ring 21 is fixed and the inner ring 22 rotates, the tone ring 30 rotates with the inner ring 22, and the tone ring 30 rotates with respect to the angle sensor 443. The air gap from the angle sensor 443 to the outer peripheral side end surface 31IF of the convex portion 31 shown in FIG. 3 and the air gap from the angle sensor 443 to the outer peripheral side end surface 32IF of the concave portion 32 shown in FIG.

  Thus, the distance between the angle sensor 443 and the tone ring 30 changes periodically. Thereby, the magnetic flux density (magnetic field) passing through the angle sensor 443 changes, and the detection voltage of the angle sensor 443 changes according to the change in magnetic flux density passing through the angle sensor 443. For example, when the angle sensor 443 and the outer peripheral side end face 31IF of the convex portion 31 of the tone ring 30 are close to each other, the magnetic flux passing through the angle sensor 443 increases. At this time, the voltage V11 shown in FIG. When the angle sensor 443 and the outer peripheral side end face 31IF of the convex portion 31 of the tone ring 30 are separated from each other, the magnetic flux passing through the angle sensor 443 is reduced. At this time, the voltage V12 shown in FIG. 9 is output from the angle sensor 443. The voltage V11> the voltage V12.

  As shown in FIG. 5, when the magnetic body 311 showing magnetism stronger than that of the tone ring 30 comes closest to the angle sensor 443, the voltage V <b> 10 shown in FIG. 9 is output from the angle sensor 443. Voltage V10> voltage V11. In the tone ring 30, the magnetic body 311 is attached to only one place. Each time the tone ring 30 makes one rotation (360 ° rotation) relative to the angle sensor 443, the magnetic body 311 comes closest to the angle sensor 443, and the voltage V10 is output once from the angle sensor 443. For this reason, the voltage V <b> 10 can be the origin of the angle detected by the angle sensor 443. In the present embodiment, a threshold value Vm is set to detect the origin. V11 <Vm ≦ V10. When the voltage output from the angle sensor 443 exceeds the threshold value Vm, the control circuit 451 can determine that the angle sensor 443 has detected the origin.

  Further, the angle sensor 443 outputs a voltage waveform for a period corresponding to the number of the convex portions 31 and the concave portions 32 shown in FIG. For example, the angle sensor 443 outputs a voltage waveform for seven cycles from when the origin is detected until the next origin is output. Outputting a voltage waveform for seven cycles means that V10 or V11 (maximum value) and seven V12 (minimum value) are alternately output. Therefore, the control circuit 451 calculates the approximate rotation angle of the tone ring 30 relative to the angle sensor 443 by counting the number of detected origins and the number of detected maximum and minimum values after the origin is detected. be able to. In addition, the control circuit 451 counts the number of detected origins, the number of detected maximum and minimum values after detecting the origin, and detects the voltage value output by the angle sensor 443, thereby detecting the angle sensor. The rotation angle of the tone ring 30 with respect to 443 can be calculated in more detail.

  As shown in FIG. 5, the angle sensor 443 is fixed to the outer ring 21 via the sensor substrate 42 and the cover 10. The tone ring 30 is fixed to the inner ring 22. For this reason, the rotation angle of the tone ring 30 with respect to the angle sensor 443 is equal to the rotation angle of the inner ring 22 with respect to the outer ring 21.

  FIG. 10 is a diagram showing a configuration example of a circuit mounted on the substrate of the sensor-equipped bearing according to the present embodiment. As shown in FIG. 10, a circuit 40A mounted on the substrate 40 (see FIG. 2) of the sensor-equipped bearing 1 includes a power generation unit 50, a power supply unit 43, a sensor 44, a control unit 45, and a voltage monitoring unit. 46 and an antenna 47. The power generation unit 50 includes the plurality of power generation units 3 shown in FIGS. 2 to 4 and the tone ring 30. The power supply unit 43 includes a rectifier circuit 431, a smoothing circuit 432, a power storage circuit 433, a chargeable / dischargeable power storage unit 434, an output control circuit 435, and a constant voltage output circuit 436.

  The power generation unit 50 generates single-phase AC power and outputs it to the rectifier circuit 431 of the power supply unit 43. The rectifier circuit 431 performs full-wave rectification on the single-phase AC power generated by the power generation unit 3 to convert it into DC power, and outputs the DC power to the smoothing circuit 432. Although a diode bridge is illustrated as the rectifier circuit 431, the present embodiment is not limited to this. The smoothing circuit 432 smoothes the DC power output from the rectifier circuit 431 and reduces the AC component from the DC power. Then, the smoothing circuit 432 outputs DC power with reduced AC components to the power storage circuit 433. The power storage circuit 433 charges the power storage unit 434 with the DC power output from the smoothing circuit 432.

  The output control circuit 435 transmits a control signal to the constant voltage output circuit 436 to control the constant voltage output circuit 436. The constant voltage output circuit 436 adjusts the DC power output from the power storage unit 434 to a constant voltage under the control of the output control circuit 435, and outputs it to the sensor 44 and the control unit 45.

  For example, the output control circuit 435 monitors the voltage of the power storage unit 434. When the voltage of the power storage unit 434 is equal to or higher than a preset threshold value (for example, a fourth management value BV4 in FIG. 11 described later), the output control circuit 435 transmits a signal instructing the constant voltage output circuit 436 to supply power. Thereby, the constant voltage output circuit 436 adjusts the DC power output from the power storage unit 434 to a constant voltage, and outputs it to the sensor 44 and the control unit 45. On the other hand, when the voltage of power storage unit 434 is less than a preset threshold value (for example, a first management value BV1 in FIG. 11 described later), output control circuit 435 provides a signal for instructing constant voltage output circuit 436 to stop supplying power. Send. As a result, the constant voltage output circuit 436 stops supplying power to the sensor 44 and the control unit 45.

  As shown in FIGS. 10 and 11, the sensor 44 detects various physical quantities or chemical quantities using supplied DC power. For example, the sensor 44 includes an acceleration sensor 441 that detects vibration of the bearing body 20 (see FIGS. 3 to 5), a temperature sensor 442 that detects the ambient temperature of the bearing body 20, and the angle sensor 443 described above. Although not shown, the sensor 44 includes a humidity sensor that detects the ambient humidity of the bearing body 20 and a gas sensor that detects gaseous hydrocarbons, hydrogen sulfide, ammonia, and the like that are generated due to the oxidative deterioration of the lubricating oil in the bearing body 20. In addition, an ultrasonic sensor or the like that detects frictional noise generated in the bearing body 20 may be provided.

  In the present embodiment, the acceleration sensor 441 has a function of outputting an interrupt signal IRS1 to the control circuit 451 of the control unit 45 when the acceleration sensor 441 detects an impact greater than or equal to a predetermined magnitude. As an impact of a predetermined magnitude or more, an acceleration of an upper limit management value UCL1 or more shown in FIG. The acceleration sensor 441 is exemplified by “Analog Devices, Inc. acceleration sensor (ADXL372)”.

  The temperature sensor 442 has a function of outputting an interrupt signal IRS2 to the control circuit 451 of the control unit 45 when the temperature sensor 442 detects a high temperature equal to or higher than a predetermined value or a low temperature equal to or lower than a predetermined value. As the high temperature above the predetermined value, for example, a temperature above the upper limit management value UCL21 shown in FIG. Moreover, the temperature below the lower limit management value LCL22 shown in FIG. 13 mentioned later is illustrated as low temperature below a predetermined value. An example of the temperature sensor 442 is “Temperature Instruments TMP007 manufactured by Texas Instruments Inc.”.

  Further, the angle sensor 443 has a function of outputting an interrupt signal IRS3 to the control circuit 451 of the control unit 45 when detecting a rotation angle or a rotation speed greater than a predetermined size.

  The control unit 45 stores data detected by the sensor 44 or transmits the data to the outside via the antenna 47. For example, the control unit 45 includes a control circuit 451, a storage circuit 452, a communication circuit 453, a counter circuit 454, and a mode restriction circuit 455. The control circuit 451 is, for example, a CPU (Central Processing Unit). The memory circuit 452 includes a nonvolatile memory. Examples of the non-volatile memory include a NAND type or NOR type flash memory. The communication circuit 453 is included in the CPU that constitutes the control circuit 451. Alternatively, the communication circuit 453 may be configured with an IC chip different from the CPU.

  The counter circuit 454 is included in the CPU that constitutes the control circuit 451. The CPU multiplies the CPU clock frequency to generate a clock signal. Then, the counter circuit 454 counts the number of rising (or falling) times of the clock signal generated by the CPU. Alternatively, the counter circuit 454 may be configured by an IC chip (for example, a binary counter IC) different from the CPU. The control circuit 451, the storage circuit 452, the communication circuit 453, and the counter circuit 454 operate using DC power supplied from the power supply unit 43.

  The mode restriction circuit 455 is included in the CPU constituting the control circuit 451. The mode restriction circuit 455 restricts the transition from the sleep mode to the normal mode based on the interval between the operation modes of the control unit 45. For example, when the control unit 45 receives the interrupt signal IRS1, IRS2, or IRS3, the mode restriction circuit 455 selects one of a first sleep mode and a second sleep mode described later. The mode regulation circuit 455 may be configured by an IC chip different from the CPU.

  The switching interval is a timing interval at which the normal mode and the sleep mode are switched, for example, an interval between BP4 and BP5 in FIG. This interval is time, and can be indicated by the count value of the counter circuit 454. When the switching interval is equal to or smaller than the predetermined value, the mode restriction circuit 455 selects the second sleep mode. Note that the switching interval can also be referred to as a switching cycle. In this case, in FIG. 14, the start of the normal mode (BP4) −the end of the normal mode and the start of the sleep mode (BP5) −the end of the sleep mode (BP4) is defined as one cycle.

  In the present embodiment, the time from the start of the sleep mode (for example, BP4 in FIG. 14) to the end of the sleep mode (for example, BP5 in FIG. 14) may not be added to the switching interval. The time from the start to the end of the normal mode may be used as the switching interval.

  The control circuit 451 controls the storage circuit 452 and the communication circuit 453. For example, the control circuit 451 converts various data detected by the sensor 44 from analog data to digital data (that is, A / D conversion). In addition, the control circuit 451 writes the A / D converted digital data in the storage circuit 452. The control circuit 451 may temporarily store the A / D converted digital data in a cache memory, read the temporarily stored digital data at an arbitrary timing, and write the digital data in the storage circuit 452. In addition, the control circuit 451 reads digital data from the storage circuit 452 and outputs the digital data to the communication circuit 453.

  In addition, the control unit 45 has GPIO (General-purpose input / output) pins as general-purpose input / output terminals. Interrupt signals IRS1, IRS2, and IRS3 output from the acceleration sensor 441, temperature sensor 442, and angle sensor 443, and a first reset signal RST1 and a second reset signal RST2 output from a first reset IC 461 and a second reset IC 462, which will be described later. Are input to the control circuit 451 of the control unit 45 via the GPIO pins. Thereby, the control circuit 451 can monitor the interrupt signals IRS1, IRS2, and IRS3, and the first reset signal RST1 and the second reset signal RST2, respectively.

  Alternatively, the control unit 45 may have a dedicated interrupt pin for inputting an interrupt signal. In this case, interrupt signals IRS1, IRS2, and IRS3 output from the acceleration sensor 441, the temperature sensor 442, and the angle sensor 443, and a first reset signal RST1 and a second reset signal that are output from a first reset IC 461 and a second reset IC 462 described later, respectively. The reset signal RST2 may be input to the control circuit 451 of the control unit 45 via an interrupt pin. Also in this case, the control circuit 451 can monitor the interrupt signals IRS1, IRS2, and IRS3, and the first reset signal RST1 and the second reset signal RST2, respectively.

  The communication circuit 453 transmits the digital data read from the storage circuit 452 to the outside via the antenna 47 under the control of the control circuit 451. For example, as illustrated in FIG. 1, the communication circuit 453 transmits digital data to the outside by wireless communication using the electromagnetic wave WV. The transmitted digital data is received by the communication unit 151 of the higher-level device 150. Digital data received by the communication unit 151 is processed by the computer 152. Thus, since the bearing 1 with a sensor can transmit digital data by radio | wireless, size reduction is attained. In the present embodiment, the digital data transmitted to the outside by the communication circuit 453 may be wired instead of wireless.

  The counter circuit 454 operates to detect the operation mode switching interval of the control unit 45. For example, the counter circuit 454 counts the number of rising (or falling) times of the clock signal multiplied by the CPU clock frequency. The count value of the counter circuit 454 is proportional to time. The control circuit 451 detects the input interval between the first reset signal RST1 and the second reset signal RST2 input to the control circuit 451 based on the count value of the counter circuit 454. For example, the input interval of the first reset signal RST1 and the second reset signal RST2 is the switching interval described above.

  In other words, the control circuit 451 is a clock that the counter circuit 454 counts during the interval (time) from when the first reset signal RST1 is input to the control circuit 451 to when the second reset signal RST2 is input next. Detection is based on the count value of the signal. Further, the control circuit 451 is a clock signal that the counter circuit 454 counts during the interval (time) from when the second reset signal RST2 is input to the control circuit 451 to when the first reset signal RST1 is input next. Detection is based on the count value.

  The voltage monitoring unit 46 monitors the voltage of the power storage unit 434. The voltage monitoring unit 46 includes a first reset IC 461 and a second reset IC 462. The first reset IC 461 outputs a first reset signal RST1 to the control circuit 451 of the control unit 45. For example, when the voltage of the power storage unit 434 is higher than a second management value BV2 (see FIG. 11 described later), the first reset IC 461 outputs a low signal having a low voltage as the first reset signal RST1. When the voltage of the power storage unit 434 is equal to or lower than the second management value BV2, the first reset IC 461 outputs a high signal having a high voltage as the first reset signal RST1. The High signal output as the first reset signal RST1 is a sleep signal described later.

  The second reset IC 462 outputs a second reset signal RST2 to the control circuit 451 of the control unit 45. For example, when the voltage of the power storage unit 434 is less than a third management value BV3 (see FIG. 11 described later), the second reset IC 462 outputs a low signal with a low voltage as the second reset signal RST2. When the voltage of the power storage unit 434 is equal to or higher than the third management value BV3, the second reset IC 462 outputs a high signal having a high voltage as the second reset signal RST2. The High signal output as the second reset signal RST2 is a wakeup signal described later. As the first reset IC 461 and the second reset IC 462, for example, “S-1009 series manufactured by SII Semiconductor Corporation” can be used, respectively.

  As described above, the power generation section 50 (see FIG. 10) of the present embodiment is such that the inner ring 22 (see FIG. 3) rotates with respect to the outer ring 21 (see FIG. 3) of the bearing body 20 (see FIG. 3). The power storage unit 434 is charged with the generated power. Thus, charging of the power storage unit 434 depends on the rotation of the inner ring 22 with respect to the outer ring 21. The power storage unit 434 is charged at any time regardless of the operations of the sensor 44 (see FIG. 10) and the control unit 45 (see FIG. 10). Based on the above, the voltage change of the power storage unit 434 will be described with reference to FIG.

  FIG. 11 is a graph schematically illustrating an example of a voltage change of the power storage unit of the present embodiment. In FIG. 11, the horizontal axis indicates time, and the vertical axis indicates the voltage of the power storage unit 434 (see FIG. 10). Moreover, L1 of FIG. 11 has shown an example of the voltage change of this embodiment. A broken line L2 in FIG. 11 indicates a voltage change in the comparative example.

  As shown in FIG. 11, in the present embodiment, a plurality of management values (for example, the first management value BV1 to the fifth management value BV5) are set in advance for the voltage of the power storage unit 434. The first management value BV1 is a voltage value when the power supply from the power storage unit 434 to the control unit 45 is switched from on to off. The second management value BV2 is a voltage value when the control unit 45 shifts from the normal mode to the sleep mode. The third management value BV3 is a voltage value when the control unit 45 returns from the sleep mode to the normal mode. The fourth management value BV4 is a voltage value when the power supply from the power storage unit 434 to the control unit 45 is switched from off to on. The fifth management value BV5 is a voltage value when the power storage unit 434 is determined to be overcharged.

  Note that the sleep mode is a state of waiting while suppressing power consumption. The power consumption per unit time is smaller in the sleep mode than in the normal mode. For example, the power consumption per unit time in the sleep mode of the CPU constituting the control unit 45 is sufficiently smaller than the power consumption per unit time in the normal mode of the CPU. In the sleep mode, the control unit 45 uses power for search and authentication (hereinafter referred to as pairing) of a connection destination (for example, the host device 150 in FIG. 1) that performs pair communication, but uses power as much as possible in other applications. Wait without consuming.

  For example, in the sleep mode, the control unit 45 stops transmission of data relating to the physical quantity or chemical quantity detected by the sensor 44 to the outside. For this reason, the power consumption per unit time of the control unit 45 is suppressed lower in the sleep mode than in the normal mode. When the control circuit 451 and the communication circuit 453 of the control unit 45 are configured by a CPU, the power consumption per unit time of the control circuit 451 and the communication circuit 453 is substantially the same as the power consumption per unit time of the CPU.

  In FIG. 11, the voltage of the power storage unit 434 is initially about 0 (V), and shows a case where power is stored from that state. When the power generation unit 50 (see FIG. 10) generates power, the generated power is stored in the power storage unit 434. When the control unit 45 (see FIG. 10) is in the sleep mode, the power consumption of the control unit 45 is kept low, so the voltage of the power storage unit 434 increases. When the voltage of the power storage unit 434 increases and the value becomes equal to or higher than the third management value BV3, the second reset IC 462 transmits a wakeup signal to the control circuit 451. When the control circuit 451 receives the wake-up signal, the control unit 45 shifts from the sleep mode to the normal mode. However, at this stage, the power supply to the sensor 44 and the control unit 45 is maintained in a stopped state by the output control circuit 435 (see FIG. 10). When the voltage of the power storage unit 434 further increases and the value becomes equal to or higher than the fourth management value BV4 (see BP1 in FIG. 11), the output control circuit 435 (see FIG. 10) causes the constant voltage output circuit 436 (see FIG. 10). A control signal is transmitted to the sensor 44 and the power supply to the sensor 44 and the control unit 45 is started.

  When power is supplied to the control unit 45 in the normal mode, data is written to and read from the memory circuit 452 by the control circuit 451, data is transmitted by the communication circuit 453, and the like. For this reason, the power consumption of the control part 45 increases and the voltage of the electrical storage part 434 falls.

  Next, when the voltage value of the power storage unit 434 becomes equal to or lower than the second management value BV2 (see BP2 in FIG. 11), the first reset IC 461 transmits a sleep signal to the control circuit 451. When the control circuit 451 receives the sleep signal, the control unit 45 shifts from the normal mode to the sleep mode. As described above, since the power consumption of the control unit 45 is kept low in the sleep mode, the voltage of the power storage unit 434 rises again.

  When the voltage of the power storage unit 434 increases and the value becomes equal to or higher than the third management value BV3 (see BP3 in FIG. 11), the second reset IC 462 transmits a wakeup signal to the control circuit 451. When the control circuit 451 receives the wake-up signal, the control unit 45 returns from the sleep mode to the normal mode. In the normal mode, since the power consumption of the control unit 45 increases, the voltage of the power storage unit 434 decreases again. When the voltage value of power storage unit 434 becomes equal to or lower than second management value BV2 (see BP4 in FIG. 11), control unit 45 receives the sleep signal from first reset IC 461 and shifts from the normal mode to the sleep mode.

  Thus, in the present embodiment, the voltage of the power storage unit 434 can be easily maintained within the range VR that is not less than the second management value BV2 and not more than the third management value BV3. Thereby, it can prevent that the electric power supplied to the sensor 44 and the control part 45 runs short. In addition, when the voltage of the power storage unit 434 is within the range VR, writing and reading of data to and from the storage circuit 452, transmission of data by the communication circuit 453, and the like are performed stably. Thereby, it is possible to prevent the sensor 44 and the control unit 45 from malfunctioning due to power shortage.

  When the voltage of the power storage unit 434 is less than the first management value BV1, even if power is supplied from the power storage unit 434 to the control unit 45, the sensor 44 and the control unit 45 do not operate due to insufficient power or are stable. It is likely not to work. Therefore, when the voltage of the power storage unit 434 is less than the first management value BV1, the output control circuit 435 (see FIG. 10) supplies power from the constant voltage output circuit 436 (see FIG. 10) to the sensor 44 and the control unit 45. Stop. When the voltage of power storage unit 434 is equal to or higher than fifth management value BV5, power storage unit 434 is overcharged. In this case, the power storage circuit 433 (see FIG. 10) interrupts charging of the power storage unit 434.

  As indicated by a broken line L2 in FIG. 11, in the comparative example, since the sleep signal is not supplied to the control circuit, the control circuit or the like may run out of power and stop. For example, if the control circuit runs out of power while writing data to the storage circuit and stops, the data may be stored in the storage circuit in a damaged state. In addition, the control circuit and the communication circuit need to be re-paired with the connection destination when power is supplied again from the power storage unit. For this reason, the comparative example consumes more energy and time.

  In the present embodiment, a sleep signal is supplied from the reset IC to the control circuit 451 before the control circuit 451 and the communication circuit 453 use up power and stop. For this reason, the sensor-equipped bearing 1 of the present embodiment can prevent data from being stored in the storage circuit 452 in a state where the data is damaged due to power shortage. Moreover, the bearing 1 with a sensor can reduce the number of times of re-pairing with a connection destination (for example, the host device 150 in FIG. 1). Thereby, the bearing 1 with a sensor can reduce the energy and time which a pairing requires.

In the present embodiment, the sensor 44 has a function of transmitting an interrupt signal to the control unit 45 when the detected value is out of a preset range. FIG. 12 is a schematic diagram illustrating an example of a change in the detection value of the acceleration sensor according to the present embodiment. In FIG. 12, the horizontal axis represents time (s), and the vertical axis represents acceleration (m / s ² ). FIG. 13 is a schematic diagram illustrating an example of a change in the detection value of the temperature sensor of the present embodiment. In FIG. 13, the horizontal axis represents time (s), and the vertical axis represents temperature (° C.).

  In the present embodiment, the sleep mode has a first sleep mode and a second sleep mode. The first sleep mode is an operation mode for shifting from the sleep mode to the normal mode with the interrupt signals IRS1, IRS2, IRS3 and the wake-up signal as triggers. The second sleep mode is an operation mode for shifting from the sleep mode to the normal mode using only the wake-up signal as a trigger. In the second sleep mode, even if the control unit 45 receives the interrupt signals IRS1, IRS2, and IRS3, the normal mode is not entered and the sleep mode is maintained.

  For example, it is assumed that when the control unit 45 is in the first sleep mode, the acceleration sensor 441 (see FIG. 10) detects an impact with a magnitude outside the preset range. In this case, in FIG. 12, when the detection value of the acceleration sensor 441 becomes equal to or higher than the preset upper limit management value UCL1, the acceleration sensor 441 transmits an interrupt signal IRS1 (see FIG. 10) to the control unit 45 (see FIG. 10). . Comparison between the detected value of the acceleration sensor 441 and the upper limit management value UCL1 is performed by an arithmetic device (not shown) built in the acceleration sensor 441.

  When receiving the interrupt signal IRS1 in the first sleep mode (for example, see BP5 in FIG. 11), the control unit 45 temporarily returns the operation mode from the first sleep mode to the normal mode. Then, the control unit 45 that has returned to the normal mode performs reception, writing, and transmission of detection data. Even when the control unit 45 is in the first sleep mode, if the acceleration sensor 441 detects abnormal data that is greater than or equal to the upper limit management value UCL1, the control unit 45 can shift to the normal mode, record the abnormal data, and transmit it to the outside. . As described above, the sensor-equipped bearing 1 can keep the power consumption of the control unit 45 low by the first sleep mode, and can not overlook abnormal data even when the control unit 45 is in the first sleep mode.

  In the normal mode, since the power consumption of the control unit 45 increases, the voltage of the power storage unit 434 decreases. Thereafter, when the detected value of the acceleration sensor 441 becomes less than the upper limit management value UCL1, the acceleration sensor 441 stops transmitting the interrupt signal IRS1 (see, for example, BP6 in FIG. 11). Thereby, the control unit 45 shifts the operation mode from the normal mode to the first sleep mode. In the first sleep mode, since the power consumption of the control unit 45 is kept low, the voltage of the power storage unit 434 increases.

  Further, it is assumed that when the control unit 45 is in the first sleep mode, the temperature sensor 442 (see FIG. 10) detects a temperature outside the preset range. In this case, in FIG. 13, when the detected value of the temperature sensor 442 becomes equal to or higher than the preset upper limit management value UCL21 or lower limit management value LCL22, an interrupt signal IRS2 (FIG. 10) is sent. Send). Comparison between the detected value of the temperature sensor 442 and the upper limit management value UCL21 or the lower limit management value LCL22 is performed by an arithmetic device (not shown) built in the temperature sensor 442.

  When receiving the interrupt signal IRS2 in the first sleep mode (see, for example, BP5 in FIG. 11), the control unit 45 temporarily returns the operation mode from the first sleep mode to the normal mode. Then, the control unit 45 that has returned to the normal mode performs reception, writing, and transmission of detection data. Even when the control unit 45 is in the first sleep mode, if the temperature sensor 442 detects abnormal data that is equal to or higher than the upper limit management value UCL21 or lower limit management value LCL22, the control unit 45 shifts to the normal mode and records the abnormal data. And can be sent to the outside. As described above, the sensor-equipped bearing 1 can keep the power consumption of the control unit 45 low by the first sleep mode, and can not overlook abnormal data even when the control unit 45 is in the first sleep mode.

  In the normal mode, since the power consumption of the control unit 45 increases, the voltage of the power storage unit 434 decreases. Thereafter, when the detected value of the temperature sensor 442 is greater than the lower limit management value LCL22 and less than the upper limit management value UCL21, the temperature sensor 442 stops transmitting the interrupt signal IRS2 (see, for example, BP6 in FIG. 11). Thereby, the control unit 45 shifts the operation mode from the normal mode to the first sleep mode. In the first sleep mode, since the power consumption of the control unit 45 is kept low, the voltage of the power storage unit 434 increases.

  Although not shown, an upper limit management value is also set in advance in the angle sensor 443 (see FIG. 10). When the detection value of the angle sensor 443 becomes equal to or higher than the upper limit management value, the angle sensor 443 transmits an interrupt signal IRS3 (see FIG. 10) to the control unit 45. The operation of the controller 45 when the interrupt signal IRS3 is received in the first sleep mode is the same as that when the interrupt signal IRS1 is received.

  FIG. 14 is a graph schematically illustrating an example of a voltage change of the power storage unit of the present embodiment. In FIG. 14, the horizontal axis indicates time, and the vertical axis indicates the voltage of the power storage unit 434 (see FIG. 10). In the example illustrated in FIG. 14, after the voltage value of the power storage unit 434 becomes equal to or lower than the second management value BV2 (for example, BP4 in FIG. 14), the voltage of the power storage unit 434 is not stabilized, and the first sleep mode and the normal mode This shows a case where the switching interval (for example, the interval between BP4 and BP5 in FIG. 14) is short.

  In such a case, the control unit 45 shifts the operation mode from the normal mode to the second sleep mode. Then, the control unit 45 maintains the second sleep mode until the voltage value of the power storage unit 434 reaches the fourth management value BV4. Even if the control unit 45 receives the interrupt signals IRS1, IRS2, and IRS3 in the second sleep mode (for example, BP6 'in FIG. 14), the control unit 45 does not shift to the normal mode and maintains the second sleep mode. Thereby, control unit 45 can achieve early recovery of the voltage of power storage unit 434.

  Next, an operation sequence of the circuit 40A illustrated in FIG. 10 will be described. FIG. 15 is a flowchart (main routine) showing an example of an operation sequence of a circuit mounted on the sensor-equipped bearing substrate of the present embodiment.

  First, the output control circuit 435 (see FIG. 10) checks the voltage of the power storage unit 434 (see FIG. 10) (step ST1). Next, the output control circuit 435 determines whether or not the voltage of the power storage unit 434 is equal to or higher than a preset fourth management value BV4 (step ST2). When the voltage of the power storage unit 434 is equal to or higher than the fourth management value BV4 (step ST2; Yes), the output control circuit 435 transmits a control signal to the constant voltage output circuit 436, and the sensor 44 (see FIG. 10) and the control unit 45. (See FIG. 10). Thereby, the constant voltage output circuit 436 supplies the constant voltage power to the sensor 44 and the control unit 45, respectively (step ST3). On the other hand, when the voltage of the power storage unit 434 is less than the fourth management value BV4 (step ST2; No), the operation sequence returns to step ST1.

  When power is supplied from the power supply unit 43, the control unit 45 performs initial setting (step ST4). For example, the control circuit 451 (see FIG. 10) and the communication circuit 453 (see FIG. 10) search and authenticate (pair) a connection destination for performing pair communication as an initial setting. In addition, the control circuit 451 sets conditions for starting and ending data transfer processing to the storage circuit 452 (see FIG. 10). For example, the start condition is detection of the origin (see FIG. 9) output from the angle sensor 443. The control circuit 451 writes information relating to the threshold value Vm (see FIG. 9) for detecting the origin into a register of the CPU constituting the control unit 45. The end condition is the number of times the origin is detected. The control circuit 451 writes the number of times of detection of the origin serving as an end condition in a register of the CPU constituting the control unit 45.

  When power of a constant voltage is supplied to the sensor 44, the sensor 44 starts detecting a physical quantity or a chemical quantity. For example, the acceleration sensor 441 detects vibration of the bearing body 20 (see FIGS. 3 to 5) and outputs analog data as detection data. The temperature sensor 442 detects the ambient temperature of the bearing body 20 and outputs analog data as detection data. The angle sensor 443 detects the rotation angle of the inner ring 22 with respect to the outer ring 21 and outputs analog data as detection data. The control circuit 451 receives analog data as detection data from the sensor 44 (step ST5). The analog data is converted into digital data by the A / D conversion function of the control circuit 451.

  The control circuit 451 writes the detection data converted into digital data in the storage circuit 452 (step ST6). For example, the control circuit 451 temporarily stores the detection data in the cache memory of the control circuit 451 and outputs the detection data stored in the cache memory to the storage circuit 452 in a time division manner (step ST6). The memory circuit 452 holds the detection data written by the control circuit 451 even when power is not supplied.

  Next, the control circuit 451 reads the detection data from the storage circuit 452 and outputs it to the communication circuit 453. The communication circuit 453 transmits the detection data from the antenna 47 to the outside (step ST7).

  After completing the transmission process by the communication circuit 453, the control circuit 451 determines whether or not to continue to detect a physical quantity or a chemical quantity (step ST8). When the detection of the physical quantity or the chemical quantity is continued (step ST8; Yes), the operation sequence proceeds to step ST10. If the detection of physical quantity or chemical quantity is not continued (step ST8; No), the operation sequence proceeds to step ST9. In step ST9, the output control circuit 435 transmits a control signal to the constant voltage output circuit 436 and instructs the sensor 44 and the control unit 45 to stop outputting. As a result, the constant voltage output circuit 436 stops supplying power to the sensor 44 and the control unit 45. Then, the circuit 40A ends the operation sequence.

  On the other hand, in step ST10, the output control circuit 435 confirms the voltage of the power storage unit 434 again. Next, the output control circuit 435 determines whether or not the voltage of the power storage unit 434 is equal to or higher than the first management value BV1 (step ST11). When the voltage of power storage unit 434 is less than first management value BV1 (step ST11; No), the operation sequence proceeds to step ST9. In this case, the constant voltage output circuit 436 stops supplying power to the sensor 44 and the control unit 45. When the voltage of power storage unit 434 is greater than or equal to first management value BV1 (step ST11; Yes), constant voltage output circuit 436 continues to supply power to sensor 44 and control unit 45.

  The first reset IC 461 of the voltage monitoring unit 46 outputs a first reset signal RST1 based on the voltage of the power storage unit 434 to the control circuit 451. Based on first reset signal RST1, control circuit 451 determines whether or not the voltage of power storage unit 434 is equal to or lower than second management value BV2 (step ST12). For example, the threshold voltage of the first reset IC 461 is set to the second management value BV2. When the voltage of the power storage unit 434 is equal to or lower than the second management value BV2, the first reset IC 461 outputs a High signal (sleep signal) as the first reset signal RST1. When the voltage of the power storage unit 434 is larger than the second management value BV2, the first reset IC 461 outputs a Low signal as the first reset signal RST1. When receiving the High signal (sleep signal) as the first reset signal RST1, the control circuit 451 determines that the voltage of the power storage unit 434 is equal to or lower than the second management value BV2 (Step ST12: Yes). Further, when receiving the Low signal as the first reset signal RST1, the control circuit 451 determines that the voltage of the power storage unit 434 is larger than the second management value BV2 (step ST12: No).

  When the voltage of power storage unit 434 is larger than second management value BV2 (step ST12; No), the operation sequence returns to step ST5. When the voltage of power storage unit 434 is equal to or lower than second management value BV2 (step ST12; Yes), mode restriction circuit 455 of control unit 45 operates based on the count value of counter circuit 451. The switching interval is confirmed (step ST13). Then, the mode regulation circuit 455 confirms whether the switching interval confirmed in step ST13 is equal to or smaller than a predetermined value or larger than the predetermined value (step ST14). When the switching interval is larger than the predetermined value (step ST14; No), the operation sequence proceeds to step ST15. If the switching interval is equal to or smaller than the predetermined value (step ST14; Yes), the operation sequence proceeds to step ST19.

  In step ST15, the control unit 45 shifts from the normal mode to the first sleep mode. And the control part 45 performs the detection process (henceforth a 1st sleep process) in 1st sleep mode (step ST16).

  FIG. 16 is a flowchart (subroutine) showing an example of the first sleep process of the present embodiment. In step ST161 in FIG. 16, the control circuit 451 determines whether or not an interrupt signal from the sensor 44 has been received. For example, when the control circuit 451 determines that any one or more of the interrupt signals IRS1, IRS2, and IRS3 (see FIG. 10) have been received (step ST161; Yes), the operation sequence proceeds to step ST162. When the control circuit 451 determines that none of the interrupt signals IRS1, IRS2, and IRS3 has been received (step ST161; No), the first sleep process ends.

  In step ST162, the control unit 45 temporarily shifts from the first sleep mode to the normal mode. Next, the control circuit 451 receives analog data as detection data from the sensor 44 (step ST163). The analog data is converted into digital data by the A / D conversion function of the control circuit 451.

  The control circuit 451 writes the detection data converted into digital data into the storage circuit 452 (step ST164). For example, the control circuit 451 temporarily stores the detection data in the cache memory of the control circuit 451 and outputs the detection data stored in the cache memory to the nonvolatile memory of the storage circuit 452 in a time division manner. The memory circuit 452 holds the detection data written by the control circuit 451 even when power is not supplied.

  Next, the control circuit 451 reads the detection data from the storage circuit 452 and outputs it to the communication circuit 453. Communication circuit 453 transmits detection data to the outside from antenna 47 (step ST165).

  Next, control circuit 451 determines whether or not the interrupt signal from sensor 44 has been received again (step ST166). When the control circuit 451 determines that any one or more of the interrupt signals IRS1, IRS2, and IRS3 have been received (step ST166; Yes), the operation sequence returns to step ST163. If control circuit 451 determines that none of interrupt signals IRS1, IRS2, and IRS3 has been received (step ST166; No), the operation sequence proceeds to step ST167. In step ST167, the control unit 45 returns to the first sleep mode (step ST167). Thereafter, the first sleep process ends.

  After the first sleep process is completed, the operation sequence proceeds to step ST17 in FIG. In step ST <b> 17, the second reset IC 462 of the voltage monitoring unit 46 outputs a second reset signal RST <b> 2 based on the voltage of the power storage unit 434 to the control circuit 451. Based on the second reset signal RST2, the control circuit 451 determines whether or not the voltage of the power storage unit 434 is greater than or equal to the third management value BV3. For example, the threshold voltage of the second reset IC 462 is set to the third management value BV3. When the voltage of the power storage unit 434 is equal to or higher than the third management value BV3, the second reset IC 462 outputs a High signal (wake-up signal) as the second reset signal RST2. When the voltage of the power storage unit 434 is less than the third management value BV3, the second reset IC 462 outputs a Low signal as the second reset signal RST2. When receiving the High signal (wake-up signal) as the second reset signal RST2, the control circuit 451 determines that the voltage of the power storage unit 434 is equal to or higher than the third management value BV3 (Step ST17: Yes). Further, when receiving the Low signal as the second reset signal RST2, the control circuit 451 determines that the voltage of the power storage unit 434 is less than the third management value BV3 (No in Step ST17).

  When the voltage of power storage unit 434 is greater than or equal to third management value BV3 (step ST17; Yes), control unit 45 transitions from the first sleep mode to the normal mode (step ST18). Thereafter, the operation sequence returns to step ST5. When the voltage of power storage unit 434 is less than third management value BV3 (step ST17; No), the operation sequence returns to step ST16. In this case, the control unit 45 maintains the first sleep mode.

  On the other hand, in step ST19, the control unit 45 shifts from the normal mode to the second sleep mode. And the control part 45 performs the detection process (henceforth 2nd sleep process) in 2nd sleep mode (step ST20).

  FIG. 17 is a flowchart (subroutine) showing an example of the second sleep process of the present embodiment. In step ST201 of FIG. 17, the control circuit 451 determines whether or not an interrupt signal from the sensor 44 has been received. For example, when the control circuit 451 determines that any one or more of the interrupt signals IRS1, IRS2, and IRS3 (see FIG. 10) have been received (step ST201; Yes), the operation sequence proceeds to step ST202. When the control circuit 451 determines that none of the interrupt signals IRS1, IRS2, and IRS3 has been received (step ST201; No), the second sleep process ends.

  In step ST202, the control circuit 451 receives analog data as detection data from the sensor 44. The analog data is converted into digital data by the A / D conversion function of the control circuit 451.

  The control circuit 451 writes the detection data converted into digital data in the storage circuit 452 (step ST203). For example, the control circuit 451 temporarily stores the detection data in the cache memory of the control circuit 451 and outputs the detection data stored in the cache memory to the nonvolatile memory of the storage circuit 452 in a time division manner. The memory circuit 452 holds the detection data written by the control circuit 451 even when power is not supplied. In the second sleep process, the communication circuit 453 does not transmit detection data. In the second sleep process, the detection data continues to be held in the storage circuit 452.

  Next, the control circuit 451 determines whether or not the interrupt signal from the sensor 44 has been received again (step ST204). When the control circuit 451 determines that any one or more of the interrupt signals IRS1, IRS2, and IRS3 has been received (step ST204; Yes), the operation sequence returns to step ST202. When the control circuit 451 determines that none of the interrupt signals IRS1, IRS2, and IRS3 has been received (step ST204; No), the second sleep process ends.

  After the second sleep process is completed, the operation sequence proceeds to step ST21 in FIG. The processing content of step ST21 is the same as the processing content of step ST17. When the voltage of power storage unit 434 is greater than or equal to third management value BV3 (step ST21; Yes), control unit 45 transitions from the second sleep mode to the normal mode (step ST18). When the voltage of power storage unit 434 is less than third management value BV3 (step ST21; No), the operation sequence returns to step ST20. In this case, the control unit 45 maintains the second sleep mode.

  The detection data stored in the storage circuit in step ST203 is transmitted to the outside in step ST18. For example, the control circuit 451 reads the detection data from the storage circuit 452 and outputs it to the communication circuit 453. The communication circuit 453 transmits detection data from the antenna 47 to the outside.

  FIG. 18 is a diagram schematically showing the relationship between the operation period of the circuit mounted on the substrate of the sensor-equipped bearing of this embodiment and the power consumption of the CPU. In FIG. 18, the horizontal axis indicates time (s), and the vertical axis indicates power consumption (W) per unit time of the CPU configuring the control circuit 451 (see FIG. 10) and the communication circuit 453 (see FIG. 10). . As shown in FIG. 18, the operation period of the circuit 40A (see FIG. 10) is divided into periods tm1 to tm3. The period tm1 is a period during which step ST4 of the flowchart shown in FIG. 15 is executed. The period tm2 is a period in which steps ST5 and ST6 of the flowchart shown in FIG. 15 are executed. The period tm3 is a period during which step ST7 of the flowchart shown in FIG. 15 is executed. In FIG. 18, EP1 indicates the power consumption (J) of the CPU in the period tm1. EP2 indicates the power consumption (J) of the CPU in the period tm2. EP3 indicates the power consumption (J) of the CPU in the period tm3. In the period tm1, an inrush current flows through the CPU. For this reason, immediately after the start of the period tm1, the power consumption per unit time of the CPU temporarily increases.

  In the present embodiment, the control unit 45 shifts to the first sleep mode or the second sleep mode and suppresses power consumption before the power stored in the power storage unit 434 is used up and stopped. In the first sleep mode or the second sleep mode, the control unit 45 maintains pairing with the connection destination while keeping power consumption low. Thereby, the bearing 1 with a sensor (refer FIG. 1) can reduce the frequency | count required of the period tm1, and can perform the period tm2 and the period tm3 repeatedly. Thereby, the bearing 1 with a sensor can reduce the ratio of the power consumption amount EP1 to the power consumption amounts EP2 and EP3.

  FIG. 19 is a graph showing an example of the change over time of the rotational speed of the bearing with sensor. The horizontal axis of FIG. 19 is time. The vertical axis | shaft of FIG. 19 is a rotational speed of a bearing with a sensor. Rsa on the vertical axis represents, for example, the rotation speed of the sensor-equipped bearing 1 when the power generated by the power generation unit 50 exceeds the power that can be stored in the power storage unit 434. Moreover, Rsb on the vertical axis is the rotational speed of the sensor-equipped bearing 1 when the power generated by the power generation unit 50 is below the minimum power consumption of various circuits of the sensor-equipped bearing 1. As shown in FIG. 19, the rotation of the sensor-equipped bearing 1 may be a high-speed rotation of Rsa or higher, or may be a low-speed rotation of Rsb or lower. Thus, since the rotation speed of the sensor-equipped bearing 1 often varies from moment to moment, the power generated by the power generation unit 50 is often not stable.

  However, the power storage circuit 433 of the sensor-equipped bearing 1 stores the electric power generated by the power generation unit 50 in the power storage unit 434 as long as the power storage unit 434 can be charged regardless of whether the rotation is high speed or low speed. . For example, the power storage circuit 433 includes a Zener diode. In the case of high-speed rotation, the power storage circuit 433 stores surplus power in the power generated by the power generation unit 50 through the Zener diode and discharges it outside, and flows the remaining power through the power storage unit 434 for storage. In the case of low-speed rotation, the power storage circuit 433 stores all power generated by the power generation unit 50 through the power storage unit 434 for storage.

  As described above, the sensor-equipped bearing 1 according to this embodiment includes the bearing body 20 having the outer ring 21 and the inner ring 22 that rotate relatively around the rotation axis Ax, and the relative relationship between the outer ring 21 and the inner ring 22. A power generation unit 50 that generates power based on rotation, a chargeable / dischargeable power storage unit 434 that is charged by power generated by the power generation unit 50, a sensor 44 that detects a physical quantity or a chemical amount of the bearing body 20, and a power storage unit 434. And a control unit 45 to which detection data related to a physical quantity or a chemical quantity detected by the sensor 44 is supplied, and a mode regulation circuit 455. The operation mode of the control unit 45 includes a normal mode and a sleep mode in which power consumption per unit time is lower than that in the normal mode. The mode regulation circuit 455 regulates the transition from the sleep mode to the normal mode based on the interval between operation mode switching.

  According to this, when the supply of power is unstable, the control unit 45 can keep power consumption low by maintaining the sleep mode. Thereby, the power storage unit 434 can recover the voltage, and can stabilize the supply of power to the control unit 45.

  Further, the sensor 44 transmits an interrupt signal IRS1, IRS2, or IRS3 to the control unit 45 under a preset condition. The sleep mode is the first sleep mode that shifts to the normal mode when the control unit 45 receives the interrupt signal IRS1, IRS2, or IRS3, and the normal mode is entered even if the control unit 45 receives the interrupt signal IRS1, IRS2, or IRS3. A second sleep mode that does not shift. The mode restriction circuit 455 selects one of the first sleep mode and the second sleep mode based on the interval between operation mode switching.

  According to this, when receiving the interrupt signal IRS1, IRS2, or IRS3 during the first sleep mode, the control unit 45 can shift to the normal mode, record the abnormal data, and transmit it to the outside. Thereby, the sensor-equipped bearing 1 can keep the power consumption of the control unit 45 low by the sleep mode, and can not overlook abnormal data even when the control unit 45 is in the sleep mode.

  Further, when the power supply from the power storage unit 434 to the control unit 45 is unstable, the normal mode time tends to be shortened. In this case, the mode restriction circuit 455 selects the second sleep mode. Even if the control unit 45 receives the interrupt signal IRS1, IRS2, or IRS3 during the second sleep mode (see, for example, BP6 'in FIG. 14), the second sleep mode is maintained and the normal mode is not shifted. Thereby, the power storage unit 434 can prioritize voltage recovery when the supply of power to the control unit 45 is unstable.

  The control unit 45 can learn a power supply pattern based on the interval between operation mode switching. When receiving the interrupt signal IRS1, IRS2, or IRS3, the controller 45 can select one of the first sleep mode and the second sleep mode based on the learned content. Thereby, the control part 45 can reflect the learned content in electric power management.

  The sensor-equipped bearing 1 further includes a counter circuit 454 that detects an interval between operation mode switching. According to this, the sensor-equipped bearing 1 can grasp the state of power supply based on the count value of the counter circuit 454.

  The sensor-equipped bearing 1 further includes a voltage monitoring unit 46 that monitors the voltage of the power storage unit 434. The voltage monitoring unit 46 transmits a first reset signal RST1 to the control unit 45 when the voltage of the power storage unit 434 becomes equal to or lower than the second management value BV2. The voltage monitoring unit 46 transmits a second reset signal RST2 to the control unit 45 when the voltage of the power storage unit 434 reaches or exceeds the third management value BV3. When the control unit 45 in the normal mode receives the first reset signal RST1, the control unit 45 in the normal mode shifts to the sleep mode. When the control unit 45 in the sleep mode receives the second reset signal RST2, the control unit 45 in the sleep mode shifts to the normal mode.

  According to this, the control unit 45 can shift from the normal mode to the sleep mode before power becomes insufficient. Thereby, the sensor-equipped bearing 1 can prevent the controller 45 from malfunctioning due to power shortage. In addition, the control unit 45 can avoid re-initialization such as pair communication or reduce the number of executions by shifting from the normal mode to the sleep mode before the power becomes insufficient. Thereby, the bearing 1 with a sensor can perform efficient electric power operation. The sensor-equipped bearing 1 can greatly extend the usable time of the sensor-equipped bearing 1.

  In addition, the voltage monitoring unit 46 includes a first reset IC 461 that transmits the first reset signal RST1 to the control unit 45, and a second reset IC 462 that transmits the second reset signal RST2 to the control unit 45. According to this, since the reset IC is used for voltage monitoring of the power storage unit 434, power consumption for voltage monitoring can be reduced.

  For example, as a method of monitoring the voltage of the power storage unit 434, a method of using the A / D conversion function of the control circuit 451 instead of using the reset IC is also conceivable. If the A / D conversion function of the control circuit 451 is used, voltage information can be obtained with a high accuracy of resolution. However, A / D conversion consumes a large amount of current. If voltage measurement of the power storage unit 434 is performed using the A / D conversion function of the control circuit 451, the power stored in the power storage unit 434 is significantly reduced. In the present embodiment, in consideration of this point, a low power consumption reset IC is used for voltage monitoring of the power storage unit 434. Thereby, the bearing 1 with a sensor can suppress the power consumption of voltage monitoring low.

  In addition, the sensor-equipped bearing 1 can execute the transition of the control circuit 451 and the communication circuit 453 from the sleep mode to the normal mode at a suitable timing by using the reset IC for voltage monitoring of the power storage unit 434.

  More specifically, when performing voltage monitoring by the A / D conversion function of the control circuit 451, it is possible to shift from the normal mode to the sleep mode, but when entering the sleep mode, the control circuit 451 has low power consumption. stand by. For this reason, the control circuit 451 does not know at what timing it should return from the sleep mode to the normal mode. Although a wake-up by a timer may be considered, since the sensor-equipped bearing 1 rotates passively to obtain electric power, there is no guarantee that electric power will recover after a certain time. For this reason, in the voltage monitoring by the A / D conversion function of the control circuit 451, it is difficult to execute the return from the sleep mode to the normal mode at a suitable timing. In this embodiment, considering this point, the reset IC is used for voltage monitoring of the power storage unit 434.

  Since the sensor-equipped bearing 1 is rotated, the amount of power generation cannot be controlled, but the power is stored no matter how low the rotational speed. This embodiment is a measure for preventing malfunction and a measure for saving power in an unstable power situation in which the rotation speed of the sensor-equipped bearing 1 fluctuates every moment. According to this embodiment, it is possible to provide the sensor-equipped bearing 1 that can save power and can prevent malfunction even in an unstable power situation.

  The control unit 45 includes a storage circuit 452 that stores detection data, and a communication circuit 453 that transmits the detection data stored in the storage circuit 452 to the outside. The normal mode is a mode in which detection data can be transmitted by the communication circuit 453. The sleep mode is a mode in which transmission of detection data by the communication circuit 453 is disabled. According to this, since the sensor-equipped bearing 1 can suppress the power consumption of the communication circuit 453 in the sleep mode, the efficiency of charging the power storage unit 434 can be increased.

  The sensor 44 includes an acceleration sensor 441, a temperature sensor 442, and an angle sensor 443. According to this, the bearing 1 with a sensor can output more useful data.

  That the detected value of the acceleration sensor 441 is equal to or lower than the upper limit management value UCL1 corresponds to the “preset condition” of the present disclosure. Alternatively, the detection value of the temperature sensor 442 described above may correspond to the “preset condition” of the present disclosure that is the upper limit management value UCL21 or more or the lower limit management value LCL22 or less. One or more signals arbitrarily selected from the interrupt signals IRS1, IRS2, and IRS3 correspond to the “first signal” of the present disclosure. The second management value BV2 described above corresponds to the “first threshold value” of the present disclosure, and the third management value BV3 described above corresponds to the “second threshold value” of the present disclosure. The sleep signal (High signal of the first reset signal RST1) described above corresponds to the “second signal” of the present disclosure. The above-described wake-up signal (High signal of the second reset signal RST2) corresponds to the “third signal” of the present disclosure. Two sensors arbitrarily selected from the acceleration sensor 441, the temperature sensor 442, and the angle sensor 443 correspond to the “first sensor” and the “second sensor” of the present disclosure.

(Modification)
In the present embodiment, the setting value of the threshold voltage when the reset IC outputs a high signal or a low signal may be rewritable by the computer 152 of the host device 150 or the like. For example, the first reset IC 461 and the second reset IC 462 may each include a register. The computer 152 of the host device 150 may be able to rewrite the second management value BV2 stored in the register of the first reset IC 461 via the communication unit 151 of the host device 150. Similarly, the computer 152 may be able to rewrite the third management value BV3 stored in the register of the second reset IC 462 via the communication unit 151. According to this, even if the user does not replace the reset IC, the voltage value when the first reset IC 461 outputs the sleep signal and the voltage value when the second reset IC 462 outputs the wakeup signal are obtained. It can be changed arbitrarily.

  In the above embodiment, the reset IC is described as the voltage monitoring circuit of the present disclosure, but the reset IC is merely an example. The voltage monitoring circuit of the present disclosure may be, for example, a voltage detector or a voltage detector that operates with low power consumption. Further, a comparator circuit including an operational amplifier with low power consumption may be used.

  Moreover, in said embodiment, although the bearing 1 with a sensor was illustrated as a rotation apparatus of this indication, the rotation apparatus of this indication is not limited to a bearing with a sensor. The rotating device of the present disclosure may be, for example, a rotating device with a sensor that is mounted coaxially with the bearing, instead of a bearing with a sensor.

1 Bearing with sensor (example of rotating device)
20 Bearing body (an example of a rotating device body)
21 Outer ring (example of first part)
22 Inner ring (example of second part)
40 substrate 40A circuit 41 power supply substrate 42 sensor substrate 43 power supply unit 44 sensor 45 control unit 46 voltage monitoring unit 47 antenna 50 power generation unit 150 host device 151 communication unit 152 computer 434 power storage unit 435 output control circuit 436 constant voltage output circuit 441 acceleration sensor 442 Temperature sensor 443 Angle sensor 451 Control circuit 452 Memory circuit 453 Communication circuit 454 Counter circuit 455 Mode restriction circuit 461 First reset IC (an example of a first voltage monitoring circuit)
462 Second reset IC (an example of a second voltage monitoring circuit)
BV1 first management value BV2 second management value BV3 third management value BV4 fourth management value BV5 fifth management value IRS1, IRS2, IRS3 interrupt signal LCL22 lower limit management value RST1 first reset signal RST2 second reset signal UCL1, UCL21 upper limit Management value

Claims (7)

A rotating device having a first part and a second part that rotate relative to each other about a rotation axis,
A power generation unit that generates electric power based on relative rotation between the first component and the second component;
A chargeable / dischargeable power storage unit that is charged by the power generated by the power generation unit;
A sensor,
A control unit to which power stored in the power storage unit and data detected by the sensor are supplied;
A mode regulation circuit,
The operation mode of the control unit is:
Normal mode,
A sleep mode that consumes less power per unit time than the normal mode,
The mode regulation circuit regulates a transition from the sleep mode to the normal mode based on an interval between switching of the operation modes. The sensor transmits a first signal to the control unit under a preset condition,
The sleep mode is
A first sleep mode that shifts to the normal mode when the control unit receives the first signal;
A second sleep mode that does not shift to the normal mode even when the control unit receives the first signal;
2. The rotating device according to claim 1, wherein the mode restriction circuit selects one of the first sleep mode and the second sleep mode based on a switching interval of the operation modes.   The rotating device according to claim 1, further comprising a counter circuit that detects an interval between switching of the operation modes. A voltage monitoring unit for monitoring the voltage of the power storage unit;
The voltage monitoring unit transmits a second signal to the control unit when the voltage of the power storage unit falls below a first threshold value,
The voltage monitoring unit transmits a third signal to the control unit when the voltage of the power storage unit is equal to or higher than a second threshold value that is higher than the first threshold value,
When the control unit in the normal mode receives the second signal, the control unit in the normal mode shifts to the sleep mode,
4. The rotating device according to claim 1, wherein when the control unit in the sleep mode receives the third signal, the control unit in the sleep mode shifts to the normal mode. 5. The voltage monitoring unit
A first voltage monitoring circuit for transmitting the second signal to the control unit;
The rotation device according to claim 4, further comprising: a second voltage monitoring circuit that transmits the third signal to the control unit. The controller is
A storage circuit for storing the data;
A communication circuit for transmitting the data stored in the storage circuit to the outside,
The normal mode is a mode that allows transmission of the data by the communication circuit,
The rotation device according to claim 1, wherein the sleep mode is a mode in which transmission of the data by the communication circuit is disabled. The sensor is
The rotation device according to any one of claims 1 to 6, further comprising: a first sensor; and a second sensor having a detection target different from that of the first sensor.

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