JP2019185611A - Non-contact measuring device and non-contact coupled sensor - Google Patents

Abstract

An object of the present invention is to increase a temperature allowed in a peripheral circuit of a sensor element in a non-contact measurement device. A measuring device-side coupling unit for non-contact coupling to a sensor circuit including a temperature sensor element; a sensor signal generating unit for outputting a sensor signal including an AC component to the measuring device-side coupling unit; A signal level detector 18 is provided in a signal transmission line between the sensor signal generator 14 and the measuring device side coupling unit 16 and detects the level of a sensor signal in the signal transmission line, and is detected by the signal level detector 18. A measuring unit that measures a physical quantity of the measurement object based on the signal level; [Selection diagram] Fig. 1

Description

  The present invention relates to a non-contact measurement device and a non-contact coupled sensor, and more particularly to a technique for electrically or magnetically coupling a sensor element to a measurement device.

  Research and development has been conducted on a technique for measuring the temperature of an object using a sensor element. There is a thermistor as a sensor element for measuring the temperature of an object. The thermistor has a property that its resistance value changes according to a change in temperature. The thermistor is attached to the object to be measured and connected to the measuring device via a cable. The measuring device measures the temperature of the object based on the resistance value of the thermistor. Since the thermistor and the measuring device are connected by a cable, measurement is easy even when the object to be measured is at a high temperature.

  However, it is difficult to measure the temperature of a frequently moving object such as an article handled in a factory or a store using a cable. Therefore, a technique for detecting a temperature rise of an article using a radio signal has been proposed. For example, Patent Document 1 describes a non-contact communication responder such as a resonance tag, a non-contact IC tag, or a non-contact IC card. A thermal fuse is used for this communication responder, and the resonance frequency changes when the thermal fuse is turned off due to a temperature rise. Due to the change in the resonance frequency, the normal article management reader cannot detect the communication responder, and instead, the abnormality sensing reader detects the communication responder. Thereby, the temperature rise of the object to which the communication responder is attached is detected.

JP 2005-157485 A

  As described above, as a technique for detecting the temperature of an article without using a cable, there is a technique using an IC that transmits and receives radio signals. However, with this technique, it is difficult to measure in an environment that exceeds the allowable temperature of the IC.

  An object of the present invention is to increase the temperature allowed for a peripheral circuit of a sensor element in a non-contact measuring device.

  The present invention includes a coupling unit coupled in a non-contact manner to a sensor circuit including a sensor element, a sensor signal generation unit that outputs a sensor signal including an AC component to the coupling unit, and the sensor signal generation unit and the coupling unit. A signal level detector that detects the level of the sensor signal in the signal transmission line, and a physical quantity in the measurement object is measured based on the signal level detected by the signal level detector. And a measuring unit.

  Preferably, the sensor signal generator includes a DC power source that outputs a DC voltage, and a switching circuit that switches the voltage output from the DC power source.

  Preferably, the coupling unit includes a coupling conductor that forms a capacitor by facing a conductor included in the sensor circuit, and the sensor signal is output to the coupling conductor.

  Preferably, a winding connected to the sensor signal generator and magnetically coupled to a winding included in the sensor circuit is provided.

  The present invention further includes a first solenoid coil, a second solenoid coil positioned in the first solenoid coil in the same extending direction as the first solenoid coil, and a sensor element, One end of the sensor element is connected to one of the first solenoid coil and the second solenoid coil, and a measuring device for measuring the physical quantity to be measured is connected to the other of the first solenoid coil and the second solenoid coil. One of the first solenoid coil and the second solenoid coil, to which the sensor element is connected, is rotatable about the axis with respect to the other, or the first solenoid coil and the second solenoid The other of the coils to which the sensor element is not connected is rotatable about the axis with respect to the other. And features.

  The present invention also provides a first cylindrical conductor, a second cylindrical conductor positioned inward of the first cylindrical conductor in the same extending direction as the first cylindrical conductor, and the second cylindrical conductor. A first solenoid coil located inside the second cylindrical conductor with the same extension direction as the conductor, and a first solenoid coil located inside the first solenoid coil with the same extension direction as the first solenoid coil. 2 solenoid coils and a sensor element, a capacitor formed by the first cylindrical conductor and the second cylindrical conductor, the first solenoid coil, and the second solenoid coil form a resonance circuit. The sensor element is connected to the resonance circuit, and a measuring device for measuring a physical quantity to be measured is connected to the first solenoid coil or the second solenoid coil, and the first cylindrical conductor and the second solenoid A first coupling unit including a coil is rotatable about an axis relative to a second coupling unit including the second cylindrical conductor and the first solenoid coil, or the second coupling unit is configured to be the first coupling unit. It is characterized by being rotatable about the axis with respect to the coupling unit.

  Further, the present invention provides a first solenoid coil, a second solenoid coil positioned inside the first solenoid coil, in the same extending direction as the first solenoid coil, and the extending direction of the second solenoid coil. Similarly, the first cylindrical conductor positioned inside the second solenoid coil and the second cylindrical shape positioned inside the first cylindrical conductor with the same extending direction as the first cylindrical conductor. A capacitor including a conductor and a sensor element, the capacitor formed by the first cylindrical conductor and the second cylindrical conductor, the first solenoid coil, and the second solenoid coil form a resonance circuit; The sensor element is connected to the resonance circuit, a measuring device for measuring a physical quantity to be measured is connected to the first solenoid coil or the second solenoid coil, and the second cylindrical conductor and The first coupling unit including the first solenoid coil is rotatable about an axis with respect to the second coupling unit including the first cylindrical conductor and the second solenoid coil, or the second coupling unit is The first coupling unit is rotatable about an axis.

  The present invention also provides a first coil, a first coupling conductor, a second coil that is magnetically coupled to the first coil, a second coupling conductor that forms a capacitor together with the first coupling conductor, A sensor element connected to a resonance circuit formed by one coil, the second coil and the capacitor, and a first coupling unit comprising the first coil and the first coupling conductor, or the second coil When the distance between the first coil and the second coil is increased by displacing the second coupling unit including the second coupling conductor, the first coupling conductor and the second coupling conductor When the distance between the first coil and the second coil is reduced by the displacement of the first coupling unit or the second coupling unit. When The distance between the serial second coupling conductor is increased, characterized in that.

  ADVANTAGE OF THE INVENTION According to this invention, the temperature accept | permitted by the peripheral circuit of a sensor element can be made high about a non-contact measuring device.

It is a figure which shows notionally the structure of a non-contact measurement system. It is a figure which shows the specific structure of a non-contact measurement system. It is a figure which shows the structural example of a non-contact coupling sensor. It is a figure which shows typically the cross section which passes along the central axis of a non-contact coupling sensor. It is a figure which shows typically the non-contact coupling sensor attached to the motor generator. It is a figure which shows typically the non-contact coupling sensor attached to the motor generator. It is a figure which shows the connection of each terminal of a non-contact coupling sensor. It is a figure which shows the modification of a non-contact coupling sensor. It is a figure which shows the non-contact coupling sensor which concerns on a 2nd modification. It is a figure which shows the non-contact coupling system which concerns on a 1st modification. It is a figure which shows the non-contact coupling system which concerns on a 2nd modification. It is a figure which shows the non-contact coupling system which concerns on a 3rd modification. It is a figure which shows the non-contact coupling sensor which implement | achieves the non-contact measurement system which concerns on a 3rd modification.

  FIG. 1 conceptually shows the configuration of a non-contact measurement system according to an embodiment of the present invention. This system measures the state of the measurement object 28 such as the temperature of the measurement object 28, the atmospheric pressure around the measurement object 28, and the humidity. Here, although embodiment which measures the temperature of the measurement target object 28 is demonstrated, this description does not limit a measurement object to temperature.

  The non-contact measurement system includes a non-contact measurement device 10 and a sensor circuit 12. The sensor circuit 12 includes a measurement target side coupling unit 22 and a sensor element circuit 24. The sensor element circuit 24 includes a temperature sensor element 26, and the temperature sensor element 26 is thermally coupled to the measurement object 28. An element constant such as a resistance value of the temperature sensor element 26 changes according to a change in the temperature of the measurement object 28, and an electrical state indicated by a voltage or current in the sensor element circuit 24 changes. The sensor element circuit 24 is connected to a measurement target side coupling unit 22 that electrically or magnetically couples the sensor element circuit 24 to the non-contact measurement device 10.

  The non-contact measurement device 10 includes a sensor signal generation unit 14, a measurement device side coupling unit 16, a signal level detection unit 18, and a measurement unit 20. The sensor signal generation unit 14 outputs an AC voltage or an AC current as a sensor signal to the measurement device side coupling unit 16. The measuring device side coupling unit 16 is electrically or magnetically coupled to the measurement target side coupling unit 22. When the temperature of the measurement object 28 changes, the electrical state of the sensor element circuit 24 changes, and the impedance when the measurement device side coupling unit 16 is viewed from the sensor signal generation unit 14 changes. As a result, the voltage appearing on the signal transmission line between the sensor signal generating unit 14 and the measuring device side coupling unit 16 and the current flowing through the signal transmission line change.

  The signal level detection unit 18 detects a voltage appearing on the signal transmission line between the sensor signal generation unit 14 and the measurement device side coupling unit 16 or a current flowing through the signal transmission line, and detects a voltage detection value or a current detection value. Is output to the measurement unit 20. The measurement unit 20 stores in advance a voltage / temperature table in which voltage detection values and temperatures are associated with each other, or a current / temperature table in which current detection values and temperatures are associated with each other. The measurement unit 20 refers to the voltage / temperature table or the current / temperature table based on the detection value of the signal level detection unit 18 and obtains the temperature of the measurement object 28.

  FIG. 2 shows a specific configuration of the non-contact measurement system according to the embodiment of the present invention. The non-contact measurement system includes a non-contact measurement device 10 and a sensor circuit 12. The non-contact measuring device 10 includes a DC voltage source 30, a switching circuit 32, a switching control unit 36, a primary winding L1, a first coupling conductor P1, a current sensor 34, and a measuring unit 20. The switching circuit 32 includes an upper switching element S1 and a lower switching element S2 whose one ends are commonly connected. Each switching element may be a MOSFET (metal-oxide-semiconductor field-effect transistor) or the like. In this case, the source of the upper switching element S1 is connected to the drain of the lower switching element S2. Between the drain and source of each switching element, a diode is connected with the source side as an anode, and a capacitor is connected in parallel to the diode.

  The terminal of the upper switching element S1 on the side opposite to the side connected to the lower switching element S2 (the upper terminal in FIG. 2) is connected to the positive terminal of the DC voltage source 30. The terminal of the lower switching element S2 on the side opposite to the side connected to the upper switching element S1 (the lower terminal in the figure) is connected to the negative terminal of the DC voltage source 30 via the negative line 39. The DC voltage source 30 may be a DC power supply circuit that converts an AC voltage into a DC voltage, or may be a battery. The DC power supply 30 and the switching circuit 32 constitute the sensor signal generation unit 14.

  One end of the primary winding L1 is connected to a connection point between the upper switching element S1 and the lower switching element S2 via the signal transmission line 38, and the other end of the primary winding L1 is connected to the lower side of the lower switching element S2. The terminal and the negative terminal of the DC voltage source 30 are connected. A first coupling conductor P1 is connected to a signal transmission line 38 that connects a connection point between the upper switching element S1 and the lower switching element S2 and the primary winding L1. A current sensor 34 is attached to the signal transmission line 38. The current sensor 34 is connected to the measurement unit 20, detects a current flowing through the signal transmission line 38, and outputs a detection value to the measurement unit 20.

  The sensor circuit 12 includes a second coupling conductor P2, a secondary winding L2, and a thermistor 40. The thermistor 40 is a temperature sensor element whose resistance value changes according to a change in temperature. One end of the secondary winding L2 is connected to the second coupling conductor P2, and one end of the thermistor 40 is connected to the other end of the secondary winding L2. The other end of the thermistor 40 is connected to a conductor (such as a ground conductor) in the measurement object 28. Capacitance may be inserted between the conductor to which the thermistor 40 is connected in the measurement object 28 and the negative electrode wire 39 connected to the negative terminal of the DC voltage source 30. The thermistor 40 is thermally coupled to the measurement object 28.

  The primary winding L1 and the first coupling conductor P1 of the non-contact measuring device 10 form a measuring device side coupling portion 16, and the secondary winding L2 and the second coupling conductor P2 of the sensor circuit 12 are coupled to the measurement target side. Part 22 is formed. The primary winding L1 and the secondary winding L2 are magnetically coupled to form a transformer, and the first coupling conductor P1 and the second coupling conductor P2 are electrically coupled to form a coupling capacitor C. .

  Next, the operation of the non-contact measurement system will be described. The switching control unit 36 repeatedly turns on and off the upper switching element S1 and the lower switching element S2 alternately. In other words, the switching control unit 36 controls the upper switching element S1 from off to on, turns the lower switching element S2 from on to off, controls the upper switching element S1 from off to on, and turns the lower switching element S2 from on to off. Repeat the operation.

  By the on / off control of the switching circuit 32, an alternating current as a sensor signal flows through the primary winding L1, and an induced electromotive force is generated at both ends of the primary winding L1. Since the secondary winding L2 is magnetically coupled to the primary winding L1, an induced electromotive force is also generated at both ends of the secondary winding L2. The primary winding L1, the coupling capacitor C, and the secondary winding L2 form a resonance circuit and resonate at a predetermined resonance frequency.

  The resistance value of the thermistor 40 changes due to a change in the temperature of the measurement object 28. The thermistor 40 is connected in series to the primary winding L1, the coupling capacitor C, and the secondary winding L2, and the resonance frequency changes due to a change in the resistance value of the thermistor 40. When the resonance frequency changes, the input impedance when the primary winding L1 side is viewed from the switching circuit 32 side also changes. Therefore, the input impedance changes according to the temperature change of the measurement object 28, and the current flowing through the signal transmission line 38 also changes.

  The current sensor 34 as the signal level detection unit 18 detects a current flowing through the signal transmission line 38 and outputs a current detection value (physical quantity indicating the magnitude of the current) to the measurement unit 20. The measuring unit 20 stores a current / temperature table in advance, and obtains a temperature corresponding to the detected current value with reference to the current / temperature table.

  In such a configuration, the sensor circuit 12 does not use an electronic component having a low allowable temperature such as an IC. Therefore, the sensor circuit 12 may be attached to the high-temperature measurement object 28. Further, since passive elements are used for the sensor circuit 12 except for the thermistor 40, the configuration of the peripheral circuit is simplified compared to the case where an IC or the like is used.

  The primary winding L1, the first coupling conductor P1, the second coupling conductor P2, the secondary winding L2, and the thermistor 40 constitute a non-contact coupling sensor that couples the non-contact measuring device 10 and the sensor circuit 12 in a non-contact manner. To do. FIG. 3 shows a configuration example of the non-contact coupling sensor 54. The terms “upper” and “lower” in the following description are for convenience of description showing the upper and lower sides of the drawings, and do not limit the posture when the non-contact coupling sensor 54 is used. The same applies to other drawings.

  The non-contact coupling sensor 54 includes a first coupling unit 42 and a second coupling unit 44. The first coupling unit 42 includes an outer container-like conductor 46 and an inner solenoid coil 48. The outer container-like conductor 46 has a container shape in which the upper end of a cylindrical conductor is closed with a circular conductor plate. The inner solenoid coil 48 is a coil in which a conducting wire is wound in a cylindrical shape. The inner solenoid coil 48 is accommodated in the outer container-like conductor 46 with the same extension direction as the outer container-like conductor 46 and the same central axis as the outer container-like conductor 46. The upper end of the inner solenoid coil 48 is joined to the ceiling surface that closes the cylindrical portion of the outer container-like conductor 46.

  The second coupling unit 44 includes an inner container-like conductor 50 and an outer solenoid coil 52. The inner container-like conductor 50 has a container shape in which the lower end of the cylindrical conductor is closed with a circular conductor plate. The outer solenoid coil 52 is a coil in which a conducting wire is wound in a cylindrical shape. The outer solenoid coil 52 is accommodated in the inner container-like conductor 50 with the same extension direction as the inner container-like conductor 50 and the same central axis as the inner container-like conductor 50. The lower end of the outer solenoid coil 52 is joined to the bottom surface that closes the cylindrical portion of the inner container-like conductor 50.

  The first coupling unit 42 is fitted into the second coupling unit 44. That is, the outer container-shaped conductor 46 covers the second coupling unit 44, the inner surface of the outer container-shaped conductor 46 is opposed to the outer surface of the inner container-shaped conductor 50, and the outer solenoid coil 52 is disposed on the outer container-shaped conductor 46. The first coupling unit 42 is fitted into the second coupling unit 44 so that the inner solenoid coil 48 enters the inner side of the outer solenoid coil 52.

  In a state where the first coupling unit 42 is fitted in the second coupling unit 44, the first coupling unit 42 is rotatable with respect to the second coupling unit 44 around the central axis. Similarly, the second coupling unit 44 is rotatable about the central axis with respect to the first coupling unit 42.

  FIG. 4 schematically shows a cross section passing through the central axis of the non-contact coupling sensor 54. The inner surface of the side wall of the outer container-shaped conductor 46 faces the outer surface of the side wall of the inner container-shaped conductor 50. As a result, the side wall of the outer container-like conductor 46 and the side wall of the inner container-like conductor 50 form a coupling capacitor C. The magnetic flux generated inside the outer solenoid coil 52 is linked to the inner solenoid coil 48. Similarly, the magnetic flux generated inside the inner solenoid coil 48 is linked to the outer solenoid coil 52. That is, the outer solenoid coil 52 and the inner solenoid coil 48 are magnetically coupled.

  An outer conductor terminal F is provided on the outer container-like conductor 46. Further, both ends of the conducting wire forming the inner solenoid coil 48 are drawn to the outside of the outer container-like conductor 46, and inner coil terminals (A, B) are provided at the respective ends.

  An inner conductor terminal G is provided on the inner container-like conductor 50. Moreover, both ends of the conducting wire forming the outer solenoid coil 52 are drawn to the outside of the inner container-like conductor 50, and outer coil terminals (D, E) are provided at the respective ends.

  In the example shown in FIG. 4, the outer conductor terminal F and the inner coil terminal A which is one of the two inner coil terminals A and B are short-circuited. 2, the outer conductor terminal F is connected to a connection point between the upper switching element S1 and the lower switching element S2 via the signal transmission line 38, and the inner coil terminal B is connected to the negative electrode line 39. To the negative terminal of the DC voltage source 30.

  Further, the inner conductor terminal G and the outer coil terminal D which is one of the two outer coil terminals D and E are short-circuited, and one end of the thermistor 40 is connected to the outer coil terminal E. The other end of the thermistor 40 is connected to a conductor (such as a ground conductor) in the measurement object. In this case, the relationship with the circuit elements in FIG. 2 is as follows. The outer container-like conductor 46 corresponds to the first coupling conductor P1, and the inner solenoid coil 48 corresponds to the primary winding L1. Further, the inner container-like conductor 50 corresponds to the second coupling conductor P2, and the outer solenoid coil 52 corresponds to the secondary winding L2. A capacitor formed by the outer container-like conductor 46 and the inner container-like conductor 50 corresponds to the coupling capacitor C.

  Of the non-contact coupling sensor 54, the portion forming the coupling capacitor and each solenoid coil has the following structure. That is, the non-contact coupling sensor 54 is positioned on the inner side of the first cylindrical conductor with the cylindrical portion (first cylindrical conductor) of the outer container-like conductor 46 and the first cylindrical conductor extending in the same direction. A cylindrical portion (second cylindrical conductor) of the inner container-shaped conductor 50 to be operated, and an outer solenoid coil 52 (the first cylindrical conductor) positioned on the inner side of the second cylindrical conductor in the same extending direction as the second cylindrical conductor. A solenoid coil), an inner solenoid coil 48 (second solenoid coil) positioned inside the first solenoid coil in the same extending direction as the first solenoid coil, and a thermistor 40 as a sensor element. . The coupling capacitor formed by the first cylindrical conductor and the second cylindrical conductor, the first solenoid coil, and the second solenoid coil form a resonance circuit, and the thermistor 40 is connected to the resonance circuit, and the first solenoid coil or A non-contact measuring device 10 for measuring a physical quantity to be measured is connected to both ends of the second solenoid coil, and the first coupling unit 42 including the first cylindrical conductor and the second solenoid coil is connected to the second cylindrical conductor and the second solenoid coil. The second coupling unit 44 including one solenoid coil is rotatable about the axis, or the second coupling unit 44 is rotatable about the axis with respect to the first coupling unit 42.

  The non-contact coupling sensor 54 shown in FIGS. 3 and 4 may be used to measure the temperature of the rotor of the motor generator. FIG. 5 schematically shows a non-contact coupling sensor 54 attached to the motor generator. The rotor 56 has a cylindrical shape, and its central axis is penetrated by the shaft 58, and the rotor 56 rotates together with the shaft 58. The rotor 56 rotates by electromagnetic action with a stator coil (not shown) and gives torque to the shaft 58. The rotor 56 is rotated by torque applied from the shaft 58 to generate an induced electromotive force in the stator coil.

  A hole penetrated by the shaft 58 is formed in the circular conductor at the lower end of the inner container-like conductor 50 and the circular conductor at the upper end of the outer container-like conductor 46. The shaft 58 passes through a hole formed in the inner container-shaped conductor 50, an inner side of the inner solenoid coil 48, and a hole formed in the outer container-shaped conductor 46. The inner container-like conductor 50 is fixed to the shaft 58 and the rotor 56 and rotates together with the shaft 58 and the rotor 56. On the other hand, the outer container-like conductor 46 is fixed to the motor generator casing 60 and does not rotate with the shaft 58. The shaft 58 rotates using a hole formed in the outer container-like conductor 46 as a bearing. The thermistor is fixed at a predetermined position in the rotor 56, one end thereof is connected to the outer coil terminal E, and the other end is connected to a conductor in the rotor 56.

  As shown in FIG. 6, the outer container-like conductor 46 may be fixed to the shaft 58 and the rotor 56. In this case, the relationship with the circuit elements in FIG. 2 is as follows. The inner container-like conductor 50 corresponds to the first coupling conductor P1, and the outer solenoid coil 52 corresponds to the primary winding L1. The outer container-like conductor 46 corresponds to the second coupling conductor P2, and the inner solenoid coil 48 corresponds to the secondary winding L2. A capacitor formed by the inner container-like conductor 50 and the outer container-like conductor 46 corresponds to the coupling capacitor C.

  A hole penetrated by the shaft 58 is formed in the circular conductor at the lower end of the outer container-like conductor 46 and the circular conductor at the upper end of the inner container-like conductor 50. The shaft 58 passes through a hole formed in the outer container-shaped conductor 46, an inner side of the inner solenoid coil 48, and a hole formed in the inner container-shaped conductor 50. The outer container-like conductor 46 is fixed to the shaft 58 and the rotor 56 and rotates together with the shaft 58 and the rotor 56. On the other hand, the inner container-like conductor 50 is fixed to the motor generator casing 60 and does not rotate with the shaft 58. The shaft 58 rotates using a hole formed in the inner container-like conductor 50 as a bearing. The thermistor is fixed at a predetermined position in the rotor 56, one end thereof is connected to the inner coil terminal B, and the other end is connected to a conductor in the rotor 56.

  Further, as shown in FIG. 7, the inner conductor terminal G and the outer coil terminal D which is one of the two outer coil terminals D and E are short-circuited. 2, the inner conductor terminal G is connected to a connection point between the upper switching element S1 and the lower switching element S2 via the signal transmission line 38, and the outer coil terminal E is connected to the negative electrode line 39. To the negative terminal of the DC voltage source 30.

  Further, the outer conductor terminal F and the inner coil terminal A which is one of the two inner coil terminals A and B are short-circuited, and one end of the thermistor 40 is connected to the inner coil terminal B. The other end of the thermistor 40 is connected to a conductor in the rotor 56.

  In the non-contact coupling sensor 54 shown in FIG. 3 and FIG. 4, even if a deviation occurs between the rotation axis of the first coupling unit 42 and the rotation axis of the second coupling unit 44, they are formed by these. The change in the capacitance of the coupling capacitor is small. While there is a portion where the distance between the inner surface of the side wall of the outer container-shaped conductor 46 and the outer surface of the side wall of the inner container-shaped conductor 50 becomes small, the inner surface of the side wall of the outer container-shaped conductor 46 and the inner container-shaped conductor 50 This is because there is a portion where the distance from the outer surface of the side wall increases.

  Further, even when the rotational axis of the first coupling unit 42 and the rotational axis of the second coupling unit 44 are misaligned, the mutual inductance change between the outer solenoid coil 52 and the inner solenoid coil 48 is not changed. small. Even if a deviation occurs between the central axis of the outer solenoid coil 52 and the central axis of the inner solenoid coil 48 due to a deviation between the rotation axis of the first coupling unit 42 and the rotation axis of the second coupling unit 44, This is because the change of the magnetic flux emitted from the other and linked to the other is small. Therefore, even when the rotation axis of the first coupling unit 42 and the rotation axis of the second coupling unit 44 are displaced, a change in the resonance frequency of the non-contact coupling sensor 54 is suppressed. As a result, measurement errors due to the displacement of the first coupling unit 42 or the second coupling unit 44 are reduced.

  FIG. 8 shows a modification of the non-contact coupling sensor. The first coupling unit 62 of the non-contact coupling sensor 54A corresponds to a configuration in which the position of the side wall of the outer container-like conductor 46 and the position of the inner solenoid coil 48 shown in FIGS. An outer peripheral solenoid coil 66 is formed on the outer side, and an inner peripheral side wall 70 is formed on the inner side. Further, the second coupling unit 64 corresponds to a configuration in which the position of the side wall of the inner container-like conductor 50 and the position of the outer solenoid coil 52 shown in FIGS. A coil 68 is formed, and an outer peripheral side wall 72 is formed inside.

  The inner surface of the outer peripheral side wall 72 faces the outer surface of the inner peripheral side wall 70, and a coupling capacitor is formed. Further, the magnetic flux generated inside the outer peripheral solenoid coil 66 is linked to the inner peripheral solenoid coil 68. Similarly, the magnetic flux generated inside the inner circumference solenoid coil 68 is linked to the outer circumference solenoid coil 66. That is, the outer peripheral solenoid coil 66 and the inner peripheral solenoid coil 68 are magnetically coupled.

  The outer peripheral side wall 72 is provided with an outer peripheral conductor terminal F1. Further, both ends of the conducting wire forming the inner peripheral solenoid coil 68 are drawn below a circular conductor plate that closes the lower end of the outer peripheral side wall 72, and inner peripheral coil terminals (A1, B1) are provided at the respective ends. For the inner peripheral side wall 70, an inner peripheral conductor terminal G1 is provided on a circular conductor plate that closes the upper end of the inner peripheral side wall 70. Moreover, both ends of the conducting wire forming the outer peripheral solenoid coil 66 are drawn above a circular conductor plate that closes the upper end of the inner peripheral side wall 70, and outer peripheral coil terminals (D1, E1) are provided at the respective ends.

  The non-contact coupling sensor 54A may be replaced with the non-contact coupling sensor 54 shown in FIG. In this case, the inner peripheral coil terminals (A1, B1), the outer peripheral coil terminals (D1, E1), and the outer peripheral conductor terminal F1 are respectively the inner coil terminals (A, B) of the non-contact coupling sensor 54 shown in FIG. ), The outer peripheral coil terminal (D1, E1), and the outer peripheral conductor terminal F1.

  Of the non-contact coupling sensor 54A, the part forming the coupling capacitor and each solenoid coil has the following structure. That is, the non-contact coupling sensor 54A includes an outer peripheral solenoid coil 66 (first solenoid coil) and an inner peripheral solenoid coil 68 (second solenoid coil) positioned on the inner side of the first solenoid coil in the same extending direction as the first solenoid coil. Solenoid coil) and the second solenoid coil in the same extending direction, the outer peripheral side wall 72 (first cylindrical conductor) located inside the second solenoid coil, and the first cylindrical conductor in the same extending direction The inner peripheral side wall 70 (second cylindrical conductor) located inside the first cylindrical conductor and the thermistor 40 as a sensor element are provided. The capacitor formed by the first cylindrical conductor and the second cylindrical conductor, the first solenoid coil, and the second solenoid coil form a resonance circuit, and the thermistor 40 is connected to the resonance circuit, and the first solenoid coil or A non-contact measuring device for measuring a physical quantity to be measured is connected to both ends of the second solenoid coil, and the first coupling unit 62 including the second cylindrical conductor and the first solenoid coil is connected to the first cylindrical conductor 72 and the first solenoid coil. The second coupling unit 64 including the two solenoid coils 68 is rotatable about the axis, or the second coupling unit 64 is rotatable about the axis with respect to the first coupling unit 62.

  Also in the non-contact coupling sensor 54A shown in FIG. 8, even when a deviation occurs between the rotation axis of the first coupling unit 62 and the rotation axis of the second coupling unit 64, the coupling capacitor formed by these The change in capacity is small. Further, even when the rotation axis of the first coupling unit 62 and the rotation axis of the second coupling unit 64 are misaligned, the mutual inductance change between the outer peripheral solenoid coil 66 and the inner peripheral solenoid coil 68 is changed. Is small. Therefore, even when a deviation occurs between the rotation axis of the first coupling unit 62 and the rotation axis of the second coupling unit 64, a change in the resonance frequency of the non-contact coupling sensor 54A is suppressed. As a result, the measurement error due to the displacement of the first coupling unit 62 or the second coupling unit 64 is reduced.

  FIG. 9 shows a non-contact coupling sensor 54B according to a second modification. The non-contact coupling sensor 54B includes a first coupling unit 82 and a second coupling unit 84. The first coupling unit 82 includes a first coil 74 and a conductor plate 78, and the second coupling unit 84 includes a second coil 76 and a conductor plate 80. In the example of FIG. 9, the first coil 74 and the second coil 76 are solenoid coils. The conductor plate 78 is connected to one end of the first coil 74. The conductor plate 80 is connected to one end of the second coil 76. The first coil 74 and the second coil 76 are arranged in a straight line so that their one ends are opposed to each other. Also, the conductor plates 78 and 80 are disposed at positions facing each other with the conductor plate 78 positioned on the lower side and the conductor plate 80 positioned on the upper side.

  The relationship with the components shown in FIG. 2 is as follows. The first coupling unit 82 is used for the non-contact measuring device 10, and the second coupling unit 84 is used for the sensor circuit 12. The first coil 74 corresponds to the primary winding L1, and the conductor plate 78 corresponds to the first coupling conductor P1. The second coil 76 corresponds to the secondary winding L2, and the conductor plate 80 corresponds to the second coupling conductor P2.

  When the first coupling unit 82 is displaced, the first coil 74 and the conductor plate 78 are displaced in conjunction with each other. When the second coupling unit 84 is displaced, the second coil 76 and the conductor plate 80 are displaced in conjunction with each other. When the distance between the first coil 74 and the second coil 76 increases, the distance between the conductor plate 78 and the conductor plate 80 decreases. When the distance between the first coil 74 and the second coil 76 decreases, the distance between the conductor plate 78 and the conductor plate 80 increases.

  Therefore, when the distance between the first coil 74 and the second coil 76 decreases due to the displacement of the first coupling unit 82 or the second coupling unit 84 and their mutual inductance increases, the conductor plate The distance between the conductive plate 78 and the conductive plate 80 increases, and the capacitance of the coupling capacitor formed by the conductive plate 78 and the conductive plate 80 decreases. In addition, when the distance between the first coil 74 and the second coil 76 increases and the mutual inductance decreases, the distance between the conductor plate 78 and the conductor plate 80 decreases, and the conductor plate 78. In addition, the capacitance of the coupling capacitor formed by the conductor plate 80 increases. Therefore, even when the first coupling unit 82 or the second coupling unit 84 is displaced, the change in the resonance frequency is suppressed, and the change in the impedance at both ends of the first coil 74 is suppressed. As a result, the measurement error due to the displacement of the first coupling unit 82 or the second coupling unit 84 is reduced.

  FIG. 10 shows a modification of the non-contact measurement system. In this system, the thermistor 40 is connected to both ends of the secondary winding L2. In this non-contact measurement system, the first coupling conductor P1 and the second coupling conductor P2 are not used. The same components as those shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  When the resistance value of the thermistor 40 changes due to a change in temperature of the measurement object 28, the input impedance when the primary winding L1 side is viewed from the switching circuit 32 side also changes. Therefore, the input impedance changes according to the temperature change of the measurement object 28, and the current flowing through the signal transmission line 38 also changes. The current sensor 34 as a signal level detection unit detects a current flowing through the signal transmission line 38 and outputs a current detection value to the measurement unit 20. The measuring unit 20 stores a current / temperature table in advance, and obtains a temperature corresponding to the detected current value with reference to the current / temperature table.

  As the non-contact coupling sensor, the non-contact coupling sensor (54, 54A) shown in FIGS. 4 and 8 may be used. In this case, among the components included in the non-contact coupling sensor (54, 54A), the inner solenoid coil 48 or the inner peripheral solenoid coil 68 and the outer solenoid coil 52 or the outer solenoid coil 66 are partially used.

  FIG. 11 shows a second modification of the non-contact measurement system. In this non-contact measurement system, the DC voltage source 30 and the switching circuit 32 shown in FIG. The same components as those shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  The AC voltage source 86 applies an AC voltage to the primary winding L1. Thereby, an alternating current as a sensor signal flows through the primary winding L1, and an induced electromotive force is generated at both ends of the primary winding L1. Since the secondary winding L2 is magnetically coupled to the primary winding L1, an induced electromotive force is also generated at both ends of the secondary winding L2. The primary winding L1, the coupling capacitor C, and the secondary winding L2 form a resonance circuit and resonate at a predetermined resonance frequency.

  When the resistance value of the thermistor 40 changes due to the temperature change of the measurement object 28, the resonance frequency of the resonance circuit changes, and the input impedance when the primary winding L1 side is viewed from the AC voltage source 86 side also changes. . Therefore, the input impedance changes according to the temperature change of the measurement object 28, and the current flowing through the signal transmission line 38 also changes.

  The current sensor 34 as a signal level detection unit detects a current flowing through the signal transmission line 38 and outputs a current detection value to the measurement unit 20. The measuring unit 20 stores a current / temperature table in advance, and obtains a temperature corresponding to the detected current value with reference to the current / temperature table.

  FIG. 12 shows a third modification of the non-contact measurement system. In this non-contact measurement system, the lower terminal (the terminal not connected to the secondary winding L2) of the thermistor 40 shown in FIG. 2 is connected to the non-contact measurement apparatus 10 via the coupling capacitor C2. This is connected to the negative electrode wire 39. In this modification, the primary winding L1, the coupling capacitor C1, the secondary winding L2, and the coupling capacitor C2 constitute a resonance circuit. The thermistor 40 is connected in series with the coupling capacitor C1, the secondary winding L2, and the coupling capacitor C2. The operation in which the non-contact measuring device 10 measures the temperature of the measurement object 28 is the same as that of the non-contact measuring device 10 shown in FIG.

  FIG. 13 shows a non-contact coupling sensor 54C that realizes this non-contact measurement system. The non-contact coupling sensor 54C divides the outer container-like conductor 46 in the non-contact coupling sensor 54 shown in FIG. 4 in a cross section perpendicular to the axial direction, and further, the inner container-like conductor 50 is perpendicular to the axial direction. It is divided by a cross section. Components that are the same as those shown in FIG. 4 are given the same reference numerals, and descriptions thereof are omitted. A first outer conductor 46-1 and a second outer conductor 46-2 are formed by dividing the outer container-like conductor 46, and a first inner conductor 50-1 and a second inner conductor 50-2 are formed by dividing the inner container-like conductor 50. Is formed. An insulator 88 is provided between the first outer conductor 46-1 and the second outer conductor 46-2, and the first outer conductor 46-1 and the second outer conductor 46-2 are integrated with each other in the axial center. Rotate to. Similarly, an insulator 88 is also provided between the first inner conductor 50-1 and the second inner conductor 50-2, and rotates integrally around the axis. The first outer conductor 46-1 and the first inner conductor 50-1 form a coupling capacitor C, and the second inner conductor 50-2 and the second outer conductor 46-2 form a coupling capacitor C2. The first inner conductor 50-1 is connected to the outer coil terminal E. The second outer conductor 46-2 is connected to the inner coil terminal B.

  In the above description, the embodiment using the thermistor which is a temperature sensor element as the sensor element has been described. As the sensor element, other sensor elements such as a pressure sensor, a humidity sensor, and an acceleration sensor may be used.

  In addition to the current sensor, a voltage sensor may be used as the signal level detection unit. In this case, the voltage sensor detects the voltage between the signal transmission line 38 and the negative electrode line 39 and outputs the voltage detection value to the measurement unit 20. The measurement unit 20 stores a voltage / temperature table in advance, and obtains a temperature corresponding to the detected voltage value with reference to the voltage / temperature table.

  In the above description, the embodiment in which the measurement object is the rotor of the motor generator has been described. However, the measurement object may be another object that rotates with respect to the non-contact measurement device.

DESCRIPTION OF SYMBOLS 10 Non-contact measuring device, 12 Sensor circuit, 14 Sensor signal generation part, 16 Measurement apparatus side coupling | bond part, 18 Signal level detection part, 20 Measurement part, 22 Measurement object side coupling | bond part, 24 Sensor element circuit, 26 Temperature sensor element, 28 Measurement object, 30 DC voltage source, 32 Switching circuit, 34 Current sensor, 36 Switching control unit, 38 Signal transmission line, 39 Negative electrode line, 40 Thermistor, 42, 62, 82 First coupling unit, 44, 64, 84 Second coupling unit, 46 outer container conductor, 48 inner solenoid coil, 50 inner container conductor, 52 outer solenoid coil, 54, 54A, 54B, 54C non-contact coupling sensor, 56 rotor, 58 shaft, 60 housing, 66 Outer peripheral solenoid coil, 68 inner peripheral solenoid coil, 70 inner peripheral side wall, 72 outer peripheral side wall, 74 first Yl, 76 second coil, 78, 80 conductive plate 86 AC voltage source, 88 an insulator.

Claims (8)

A coupling portion coupled in a non-contact manner to a sensor circuit including a sensor element;
A sensor signal generation unit that outputs a sensor signal including an AC component to the coupling unit;
A signal level detection unit that is provided in a signal transmission line between the sensor signal generation unit and the coupling unit and detects a level of the sensor signal in the signal transmission line;
A non-contact measurement apparatus comprising: a measurement unit that measures a physical quantity in the measurement object based on the signal level detected by the signal level detection unit. In the non-contact measuring device according to claim 1,
The sensor signal generator is
DC power supply that outputs DC voltage;
And a switching circuit for switching a voltage output from the DC power supply. In the non-contact measuring device according to claim 1 or 2,
The coupling portion is
A coupling conductor that forms a capacitor by facing a conductor included in the sensor circuit;
The non-contact measuring apparatus, wherein the sensor signal is output to the coupling conductor. In the non-contact measuring device according to any one of claims 1 to 3,
A non-contact measuring device comprising a winding connected to the sensor signal generator and magnetically coupled to a winding included in the sensor circuit. A first solenoid coil;
A second solenoid coil positioned inward of the first solenoid coil in the same extending direction as the first solenoid coil;
A sensor element,
One end of the sensor element is connected to one of the first solenoid coil and the second solenoid coil,
A measuring device for measuring a physical quantity to be measured is connected to the other of the first solenoid coil and the second solenoid coil,
One of the first solenoid coil and the second solenoid coil, to which the sensor element is connected, is rotatable about the axis with respect to the other, or the first solenoid coil and the second solenoid coil The non-contact coupling sensor characterized in that the other, to which the sensor element is not connected, is rotatable about the axis with respect to the other. A first tubular conductor;
A second cylindrical conductor positioned inward of the first cylindrical conductor in the same extending direction as the first cylindrical conductor;
A first solenoid coil positioned inward of the second cylindrical conductor, in the same extending direction as the second cylindrical conductor;
A second solenoid coil positioned inward of the first solenoid coil in the same extending direction as the first solenoid coil;
A sensor element,
A capacitor formed by the first cylindrical conductor and the second cylindrical conductor;
The first solenoid coil;
The second solenoid coil forms a resonant circuit;
The sensor element is connected to the resonant circuit;
A measuring device for measuring a physical quantity to be measured is connected to the first solenoid coil or the second solenoid coil,
A first coupling unit including the first cylindrical conductor and the second solenoid coil is rotatable about an axis relative to a second coupling unit including the second cylindrical conductor and the first solenoid coil; or The non-contact coupling sensor, wherein the second coupling unit is rotatable about an axis with respect to the first coupling unit. A first solenoid coil;
A second solenoid coil positioned inward of the first solenoid coil in the same extending direction as the first solenoid coil;
A first cylindrical conductor positioned inward of the second solenoid coil in the same extending direction as the second solenoid coil;
A second cylindrical conductor positioned inward of the first cylindrical conductor in the same extending direction as the first cylindrical conductor;
A sensor element,
A capacitor formed by the first cylindrical conductor and the second cylindrical conductor;
The first solenoid coil;
The second solenoid coil forms a resonant circuit;
The sensor element is connected to the resonant circuit;
A measuring device for measuring a physical quantity to be measured is connected to the first solenoid coil or the second solenoid coil,
A first coupling unit including the second cylindrical conductor and the first solenoid coil is rotatable about an axis with respect to a second coupling unit including the first cylindrical conductor and the second solenoid coil; or The non-contact coupling sensor, wherein the second coupling unit is rotatable about an axis with respect to the first coupling unit. A first coil;
A first coupling conductor;
A second coil magnetically coupled to the first coil;
A second coupling conductor forming a capacitor with the first coupling conductor;
A sensor element connected to a resonant circuit formed by the first coil, the second coil, and the capacitor;
The first coil and the second coil are displaced by displacement of the first coupling unit including the first coil and the first coupling conductor, or the second coupling unit including the second coil and the second coupling conductor. The distance between the first coupling conductor and the second coupling conductor decreases,
When the distance between the first coil and the second coil decreases due to the displacement of the first coupling unit or the second coupling unit, the first coupling conductor and the second coupling conductor Non-contact coupled sensor, characterized in that the distance between them increases.