JP2013102098A - Sensor holding device and sensor holding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sensor holding device capable of remotely measuring pressing force against an object to be monitored and measured of a sensor holding section and easily and remotely adjusting the pressing force on the basis of a measurement result of the pressing force, and further to provide a sensor holding method.SOLUTION: A sensor holding device 10A comprises: a sensor holding section 12 which holds a sensor 11 to be brought into contact with piping 2 and comprises an electromagnet coil 16 generating magnetic force; a power supply circuit 22 for supplying a direct current to the electromagnet coil 16 and a high frequency power source 26 for supplying a high frequency current thereto; a coupler 27 for superimposing the high frequency current supplied from the high frequency power source 26 on the direct current supplied from the power supply circuit 22; an AC voltage measuring instrument 29 for measuring AC components of voltage signals at both ends of the electromagnet coil 16 which is extracted by a first filter 28; and a DC voltage measuring instrument 31 for measuring DC components of voltage signals at both the ends of the electromagnet coil 16 which is extracted by a second filter 30.

Description

  The present invention relates to a sensor holding device and a sensor holding method for holding a sensor.

  In monitoring or measurement (hereinafter referred to as “monitoring measurement”) performed by attaching a sensor to equipment, piping, etc., when performing monitoring or measurement over a long period of time, the sensor mounting state affects the environmental condition of the mounting location. It is required to maintain the set mounting state (especially pressing force) at all times.

  In particular, when monitoring and measuring objects such as equipment and piping are placed in an atmosphere that is not accessible to people or in an environment where the number of transmission cables is restricted due to complexity, narrowness, airtightness, etc. If monitoring measurement cannot be performed by attaching a sensor to the monitoring measurement object by processing the measurement object or attaching it to the monitoring measurement object, some kind of sensor holding device and holding method are required. .

  In an atmosphere where people cannot enter, the sensor holding device needs to be remotely moved to an object to be monitored and measured using an access means such as a manipulator. Therefore, a small and lightweight sensor holding device is desired. Moreover, when environmental conditions (temperature, radiation) change remarkably, a strong sensor holding device excellent in environmental resistance is essential.

  Reflecting such circumstances, a sensor holding device using a magnet has been proposed in the case where an object to be monitored and measured is an object (equipment, piping, etc.) provided with a magnetic material. The sensor holding device using a magnet has a simple configuration such that the sensor can be held in equipment, piping, etc. by the magnetic force of the magnet without processing or sticking, and the number of cables can be reduced. While there are advantages such as, there are also problems.

  For example, when a permanent magnet is used as a magnet to be applied to the sensor holding device, a cable for adsorbing (fixing) to a monitored measurement object such as equipment or piping is not necessary. Cannot be adjusted. Therefore, there is a problem that considerable work is required for the operation of adjusting the pressing pressure (pressing force) of the sensor and the operation of attaching or removing the sensor.

  In addition, since the attracting force of the permanent magnet decreases at high temperatures, it is necessary to use a permanent magnet with a large attracting force and to add a function to adjust the attracting force so that the sensor does not come off. There is a problem of complicated mechanism and high price.

  Furthermore, since many of the small and powerful permanent magnets that have been commercialized these days are magnets containing a cobalt material, when using such a magnet containing a cobalt material in a high-level radiation atmosphere, There is also a problem that cobalt contained in the magnet is activated by radiation, and handling after use may be difficult.

  On the other hand, when an electromagnet is used as a magnet to be applied to the sensor holding device, a permanent magnet is used as a magnet to be applied to the sensor holding device because a cable for supplying an unnecessary exciting current is required when using a permanent magnet. Although the structure is slightly more complicated than in the case, by controlling the excitation current, the attractive force that could not be adjusted when using a permanent magnet as the magnet applied to the sensor holding device can be easily and remotely controlled. Can be adjusted. For example, Japanese Patent Application Laid-Open Publication No. 2003-59716 (Patent Document 1) or the like is known as a technique for adjusting the magnetic force of an electromagnet applied to a sensor holding device by adjusting the excitation current to adjust the attraction force to the monitoring measurement object. It is described in.

  In the conventional sensor holding device as described in Patent Document 1 described above, the sensor pressing force can be adjusted by controlling the excitation current. There is an advantage that the operation of adjusting the pressing pressure (pressing force) and the operation of attaching or removing the sensor are facilitated. In addition, even when used in a high-level radiation atmosphere, there is an advantage that handling is relatively easy because a problem of activation such as a permanent magnet containing a cobalt material cannot be brought about.

JP 2003-59716 A

  FIG. 19 is a schematic view showing an example of a conventional sensor holding device and sensor holding method. FIGS. 20 and 21 are configuration diagrams showing the device configuration of a conventional sensor holding device when a permanent magnet is applied to the sensor holding unit and when an electromagnet is applied to the sensor holding unit, respectively.

  In FIG. 19, the code | symbol 1 is the isolation | separation room which the piping 2 which is a monitoring measurement object penetrates. The sensor holding unit 101 of the conventional sensor holding device 100 includes, for example, a sensor holder 103 that holds a sensor 102 such as an AE sensor (ultrasonic transducer) for detecting whether or not a crack is generated in the pipe 2. , Attached to the sensor holder 103, and provided with a suction means for the pipe 2 composed of a plurality of permanent magnets 104 such as two.

  A sensor probe 105 is provided at the tip of the sensor 102 and is in contact with the monitoring measurement object 2. A signal detected by the sensor probe 105 is transmitted by a transmission cable 106 to a sensor signal processing device 107 provided outside the isolation chamber 1. The sensor signal processing device 107 constantly receives a signal detected by the sensor probe 105, and performs a process of determining whether or not a crack has occurred in the pipe 2 that is a monitoring measurement object based on the received signal.

  For example, in the sensor holding device 100 using the electromagnet 108 as the attracting means shown in FIG. 21 and the like, as in the sensor holding device 100 using the permanent magnet 104 as the attracting means, an AE sensor (ultrasonic transducer) for detecting cracks. A sensor probe 105 is provided at the tip of the sensor 102 and is in contact with the monitoring measurement object 2 with a constant pressing pressure. Then, based on the signal acquired by the sensor signal processing device 107 that has acquired the signal detected by the sensor probe 105, it is determined whether or not a crack has occurred in the pipe 2 that is the monitoring measurement object.

  The sensor holding device 100 using the electromagnet 108 as the attracting means supplies the exciting current (Ic) to the electromagnet coil from the power supply circuit 110 having the DC constant current power supply 109 provided outside the isolation chamber 1 to work as the electromagnet 108. (Electromagnetic adsorption), the sensor probe 105 is pressed against the pipe 2 which is a monitoring measurement object. The pressure for pressing the sensor probe 105 against the pipe 2 can be increased or decreased by adjusting the excitation current (Ic) supplied from the DC constant current power source 109.

  When a magnet, that is, a permanent magnet 104 or an electromagnet 108 is used for the sensor holding unit 101 of the sensor holding device 100, the structure such as a reduced number of cables is relatively simple, the ambient temperature at which the sensor holding device 100 is used, In a relatively stable environment where the radiation dose hardly changes, the change in the pressing force for pressing the sensor probe 105 against the pipe 2 is small.

  However, when a conventional sensor holding device such as the sensor holding device 100 is used in an environment where the temperature and radiation dose vary significantly in an atmosphere that cannot be entered by humans, the pressing force for pressing the sensor probe 105 against the pipe 2 is Since the change becomes large, it is difficult to apply the sensor holding device 100 using the conventional permanent magnet 104 or electromagnet 108. In particular, once installed, it is difficult to apply the conventional sensor holding device 100 using the permanent magnet 104 that cannot adjust the amount of pressing force.

  Further, even when the electromagnet 108 is adopted as the magnet of the sensor holding device 100, the pressing force (adsorption force) changes as the temperature changes. Therefore, the present invention is applied to a severe environment where people cannot enter or a complicated and narrow site. To adjust the pressing force, it is necessary to be able to maintain the set mounting state (especially pressing force) at all times. And when it is applied in a complicated and narrow field, work to attach the sensor remotely using an access device (manipulator, etc.) occurs. Therefore, it is small and lightweight due to accessibility, etc. It is necessary to be able to grasp the condition remotely.

  That is, when applying the sensor holding device 100 and the sensor holding method using the conventional magnet in a severe environment where a person cannot enter or a complicated and narrow site, the sensor holding unit 101 can be easily attached and detached. It is necessary to satisfy that the pressing state can be detected and adjusted remotely, that the sensor holding unit 101 is small and lightweight, and that the number of cables is small.

  The present invention has been made in consideration of the above-described circumstances, and can be applied to a severe environment or a complicated and narrow site where a person cannot enter without greatly complicating the configuration compared to the conventional one. A sensor holding device and a sensor holding method capable of remotely determining the pressing force of the sensor holding unit on the monitoring measurement object and easily adjusting the strength of the pressing force according to the obtained pressing force strength The purpose is to provide.

  In order to solve the above-described problem, a sensor holding device according to an embodiment of the present invention holds a sensor that is in contact with a monitoring / measurement object that is an object of monitoring or measurement, and generates a magnetic force upon receiving an excitation current. A sensor holding unit including an electromagnet coil, a DC current supply unit that supplies a DC current to the electromagnet coil, a high frequency current supply unit that supplies a high frequency current to the electromagnet coil, and the DC current supply unit to the electromagnet coil An AC component superimposing unit that superimposes a high-frequency current supplied from the high-frequency current supplying unit on a supplied DC current, and an AC voltage measuring unit that extracts an AC component of a voltage signal at both ends of the electromagnetic coil and measures an AC voltage And a DC voltage measuring unit for measuring a DC voltage by extracting a DC component of a voltage signal at both ends of the electromagnet coil.

  In order to solve the above-described problem, a sensor holding method according to an embodiment of the present invention holds a sensor to be in contact with a monitoring or measurement object that is an object of monitoring or measurement, and generates a magnetic force by receiving an excitation current. Means for providing an electromagnet coil, means for supplying a DC current as the excitation current to the electromagnet coil, means for supplying a high-frequency current, and means for supplying the high-frequency current to the DC current supplied to the electromagnet coil Using at least one of means for superimposing a high frequency current to be supplied, an AC component of a voltage signal at both ends of the electromagnet coil, and a voltage signal at both ends of the means for supplying the high frequency current, the sensor is attached to the monitoring measurement object. A physical quantity indicating a known relationship with respect to a proximity distance indicating a distance from the monitoring measurement object having a known relationship with the pressing force to be pressed is obtained. The physical quantity obtained by the means, the means for extracting the direct current component of the voltage signal at both ends of the electromagnet coil and measuring the direct current voltage, and the means for obtaining the physical quantity indicating the known relation to the proximity distance and the known relation Means for calculating the pressing force using the control unit, and means for controlling the pressing force so that the pressing force calculated by the means for calculating the pressing force is within a preset range when the pressing force is not within a preset range; A method for holding a sensor, comprising: a step of supplying the high-frequency current to the electromagnetic coil; and a means for superimposing the high-frequency current supplying the direct current. The high frequency current supplied to the electromagnet coil is overlapped with the direct current supplied to the electromagnet coil from the step of supplying the high frequency current to the electromagnet coil. And at least one of the AC component of the voltage signal at both ends of the electromagnet coil and the voltage signal at both ends of the means for supplying the high-frequency current. A physical quantity indicating a known relationship with respect to a proximity distance indicating a distance from the monitoring measurement object having a known relationship with a pressing force for pressing the sensor against the monitoring measurement object.

Schematic which shows the example of application of the sensor holding | maintenance apparatus and sensor holding method which concern on embodiment of this invention. The block diagram which showed in more detail the structural example of the sensor holding part which the sensor holding | maintenance apparatus which concerns on embodiment of this invention comprises. The block diagram which showed the example of a structure of the outer side (outdoor) of an isolation room among the sensor holding | maintenance apparatuses which concern on embodiment of this invention. The block diagram which showed the structural example of the holding | maintenance state monitor circuit as a monitoring part which the sensor holding | maintenance apparatus which concerns on embodiment of this invention comprises. Explanatory drawing which showed schematically the phenomenon which arises when a high frequency current is sent through the electromagnet coil of the sensor holding part with which the sensor holding apparatus which concerns on embodiment of this invention comprises. It is a figure explaining the change of the amplitude and phase of an electromagnet voltage when the distance of an electromagnet coil and piping changes, (A) is a case where the distance of an electromagnet coil and piping is far, (B) is an electromagnet coil and piping. (C) is explanatory drawing which shows a reference | standard waveform and an observation waveform in case the distance of an electromagnet coil and piping is near. 4 is an explanatory diagram showing a relationship between a proximity distance G that is a distance between an electric conductor and an electromagnet coil 16 and an electromagnet voltage Vfs that is a voltage across the electromagnet coil 16; The block diagram which showed the structure of the sensor holding | maintenance apparatus which concerns on the 1st Embodiment of this invention. Is an explanatory view showing a waveform measured at the measuring point _P A to P _D shown in FIG. 8, (A), (B ), (C) and (D), respectively, the measurement point _P A, P _B, explanatory view showing a waveform measured by _{P C} and _{P D.} Explanatory drawing explaining the resistance value characteristic of the electromagnet coil applied to the sensor holding part of the sensor holding apparatus which concerns on embodiment of this invention. It is explanatory drawing explaining the relationship (proximity distance characteristic) of the electromagnetism voltage Vfs of the electromagnet coil applied to the sensor holding part of the sensor holding | maintenance apparatus which concerns on embodiment of this invention, and the proximity distance G, (A) is temperature T FIG. 4B is an explanatory diagram illustrating the relationship between the proximity distance characteristics, FIG. 5B is an explanatory diagram illustrating the relationship between the coefficient Ac and the temperature T, and FIG. 5C is an explanatory diagram illustrating the relationship between the coefficient Bc and the temperature T; Explanatory drawing explaining the pressing force characteristic which presses the sensor hold | maintained at the sensor holding | maintenance part of the sensor holding | maintenance apparatus which concerns on embodiment of this invention to the monitoring measurement target object. The block diagram which showed the structure of the sensor holding | maintenance apparatus which concerns on the 2nd Embodiment of this invention. The block diagram which showed the structure of the sensor holding | maintenance apparatus which concerns on the 3rd Embodiment of this invention. Explanatory drawing which shows the relationship (proximity distance characteristic) of the phase difference P detected by the phase difference detector applied to the sensor holding | maintenance apparatus which concerns on the 3rd Embodiment of this invention, and the proximity distance G. FIG. The block diagram which showed the structure of the sensor holding | maintenance apparatus which concerns on the 4th Embodiment of this invention. The block diagram which showed the structure of the sensor holding | maintenance apparatus which concerns on the 5th Embodiment of this invention. It is explanatory drawing which shows the relationship of the frequency f of the high frequency power supply in the sensor holding | maintenance apparatus which concerns on the 5th Embodiment of this invention, the phase difference P which a phase difference detector detects, and the proximity distance G, (A) is the frequency f. Explanatory drawing which shows the relationship of the proximity distance G with respect to the phase difference P at the time of changing, (B) is explanatory drawing which shows the relationship of the phase difference P with respect to the frequency f at the time of changing the proximity distance G. Schematic which shows an example of the conventional sensor holding | maintenance apparatus and a sensor holding | maintenance method. The block diagram which showed the apparatus structure of the conventional sensor holding apparatus which applied the permanent magnet to the sensor holding part. The block diagram which showed the apparatus structure of the conventional sensor holding apparatus which applied the electromagnet to the sensor holding part.

  Hereinafter, a sensor holding device and a sensor holding method according to embodiments of the present invention will be described with reference to the accompanying drawings.

(Constitution)
FIG. 1 is a schematic diagram illustrating an application example of a sensor holding device and a sensor holding method according to an embodiment of the present invention.

  A sensor holding device 10 as an example of a sensor holding device according to an embodiment of the present invention includes a sensor holding unit 12 that holds a sensor 11 that detects a physical quantity, and a monitoring unit that monitors the holding state of the sensor holding unit 12. (Not shown in FIG. 1).

  In the sensor holding device 10 shown in FIG. 1, for example, a pipe 2 that is an example of a monitoring measurement object (monitoring measurement object) disposed in an isolation chamber 1 that is an example of a space that a person cannot enter in principle. The sensor holding unit 12 is attached to the control panel (see FIG. 1), and the signal indicating the physical quantity detected by the sensor 11 has a monitoring unit installed in an external region across the sensor 11, the isolation chamber 1, and the wall 3. The signal is transmitted from the sensor 11 to the monitoring unit through the wiring 13 that is connected so as to be able to transmit signals.

  FIG. 2 is a configuration diagram showing the configuration example of the sensor holding unit 12 included in the sensor holding device 10 which is an example of the sensor holding device according to the embodiment of the present invention in more detail.

  The sensor holding unit 12 includes an electromagnet coil 16, an iron core 17, and a sensor fixture 18 made of a nonmagnetic material. Here, reference numeral 13 a is a wiring for supplying an exciting current to the electromagnet coil 16, and reference numeral 13 b is a wiring for transmitting a signal indicating a physical quantity detected by the sensor 11.

  When an excitation current is supplied to the electromagnet coil 16, the sensor holding unit 12 is attracted to a pipe (monitoring / measurement object) 2 made of a magnetic material by a magnetic force caused by a magnetic field generated by the excitation current. The sensor 11 is integrated with the electromagnet coil 16 and the iron core 17 by the sensor fixture 18, and is pressed against the pipe 2 by the electromagnetic adsorption force of the electromagnet coil 16.

  FIG. 3 is a configuration diagram illustrating a configuration example of the outside (outdoor) of the isolation chamber 1 in the sensor holding device 10 which is an example of the sensor holding device according to the embodiment of the present invention.

  As shown in FIG. 3, a control panel 20 is installed outside the wall 3 of the isolation chamber 1, and the control panel 20 has a holding state monitor as a monitoring unit that monitors the holding state of the sensor holding unit 12. A circuit 21, a power supply circuit 22 that supplies an excitation current (direct current) to the electromagnet coil 16, and a sensor signal processing circuit 23 that acquires information on a physical quantity detected by the sensor 11 through signal processing transmitted from the sensor 11 are provided. It is done. The holding state monitor circuit 21 and the power supply circuit 22 are connected in parallel.

  FIG. 4 is a configuration diagram illustrating a configuration example of the holding state monitor circuit 21 as a monitoring unit included in the sensor holding device 10 which is an example of the sensor holding device according to the embodiment of the present invention.

  The holding state monitor circuit 21 applies an excitation current (direct current) supplied from the power supply circuit 22 as a direct current supply unit to the electromagnet coil 16 and an excitation current (direct current) supplied from the high frequency power supply 26 as a high frequency current supply unit to the electromagnet coil 16. The first filter 28 and the AC voltage measuring device 29 as an AC voltage measuring unit that extracts and measures the AC component from the voltage signals at both ends of the electromagnet coil 16. And a second filter 30 and a DC voltage measuring device 31 as a DC voltage measuring unit that extracts and measures a DC component from the voltage signals at both ends of the electromagnet coil 16.

  In the holding state monitor circuit 21, a coupler 27, a first filter 28, and a second filter 30 are connected in parallel. The coupler 27 includes a line 32 connected to the power supply circuit 22. Connected via a switch SW. The coupler 27, the first filter 28, and the second filter 30 are connected in series with a high-frequency power source 26, an AC voltage measuring device 29, and a DC voltage measuring device 31, respectively.

  For example, as shown in FIG. 5 to be described later, the high frequency power supply 26 is connected to the pipe 2 when an electromagnet having an excitation current that is a current supplied from the high frequency power supply 26 is brought close to the pipe 2 which is an example of an electric conductor. It is an AC constant current power source having a frequency high enough to generate eddy current.

  The first filter 28 is a filter having a function of allowing the high frequency component of the high frequency power supply 26 to pass therethrough. The first filter 28 is configured by, for example, a high-pass filter (high-pass filter: HPF) that blocks a frequency component lower than the cutoff frequency (cut-off frequency) and passes a frequency component higher than the cutoff frequency.

  The AC voltage measuring device 29 is a measuring device that measures an AC voltage. The holding state monitor circuit 21 measures a high-frequency component (AC voltage) that has passed through the first filter 28 from the voltage signal of the high-frequency power supply 26.

  The second filter 30 is a filter having a function of passing a DC component of the high frequency power supply 26. The second filter 30 is configured by, for example, a low-pass filter (low-pass filter: LPF) that cuts off a frequency component higher than the cutoff frequency (cut-off frequency) and passes a frequency component lower than the cutoff frequency.

  The DC voltage measuring device 31 is a measuring device that measures a DC voltage. The holding state monitor circuit 21 measures a DC component (DC voltage) that has passed through the second filter 30 in the voltage signal of the high frequency power supply 26.

  The first filter 28 is not necessarily limited to a high-pass filter, as long as it is a filter that cuts off low-frequency components including direct current components and allows effective frequency bands (high-frequency components) to pass as signal components. Absent. For example, a band pass filter (band pass filter: BPF) in which a cutoff frequency is also set on the high frequency side may be used.

  In FIG. 4, the AC voltage measuring device 29 and the DC voltage measuring device 31 are configured separately from the first filter 28 and the second filter 30, respectively, but may be configured integrally. . That is, the first filter 28 may be built in the AC voltage measuring device 29, or the second filter 30 may be built in the DC voltage measuring device 31.

(Measurement principle)
FIG. 5 is an explanatory diagram schematically showing a phenomenon that occurs when a high-frequency current is passed through the electromagnet coil 16 of the sensor holding unit 12.

  When a high-frequency constant current is supplied from the high-frequency power source 36 to the electromagnet coil 16, an eddy current flows near the surface of the pipe 2, which is an example of a nearby conductor, as shown in FIG. 5, thereby reducing the voltage of the electromagnet coil 16. Effect (back electromotive force) occurs. Here, V shown in FIG. 5 is a voltage (electromagnet voltage) at both ends of the electromagnet coil 16.

  FIG. 6 is a diagram for explaining changes in the amplitude and phase of the voltage (electromagnet voltage) at both ends of the electromagnet coil 16 when the distance between the electromagnet coil 16 and the pipe 2 is changed, and FIG. FIG. 7 is an explanatory diagram showing a reference waveform and an observation waveform 39 when the distance between the pipe 2 and the pipe 2 is long, and an explanatory diagram showing the reference waveform 38 and the observation waveform 39 when FIG. 6C is close. In FIG. 6B, the distance between the electromagnet coil 16 and the pipe 2 is closer than that shown in FIG. 6A and farther than that shown in FIG. 6C (hereinafter simply “medium”). In this case, the reference waveform 38 and the observed waveform 39 are explanatory diagrams.

  As shown in FIGS. 6 (A) to 6 (C), the amplitude and phase shift of the voltage of the electromagnet coil 16 decrease as the distance between the electromagnet coil 16 and the pipe 2 decreases, and the high-frequency waveform is reduced. It can be seen that the delayed phase shift increases. Therefore, if the voltage V between both ends of the electromagnetic coil 16 in the holding state is detected, the distance (proximity distance) between the sensor holding unit 12 and the pipe 2 which is an example of the monitoring measurement object can be obtained.

  FIG. 7 is an explanatory diagram (graph) showing the relationship between the proximity distance G, which is the distance between the conductor and the electromagnet coil 16, and the voltage V across the electromagnet coil 16.

  When a high-frequency constant current is passed through the electromagnet coil 16, a counter electromotive force is generated at the start of current supply. However, after a sufficient time has elapsed (becomes a steady state), the electromagnet coil Only a DC voltage corresponding to a voltage drop due to 16 conductor resistances is obtained. By detecting this DC voltage, that is, the voltage between the electromagnet coils 16 in a steady state, the conductor resistance of the electromagnet coils 16 can be obtained. The temperature around the electromagnet coil 16 can be obtained from the obtained conductor resistance of the electromagnet coil 16 by examining the relationship between the resistance value and the temperature of the wiring 13a constituting the electromagnet coil 16 in advance.

  Further, the proximity distance and the pressure (pressing force) that presses the sensor held by the sensor holding unit 12 against the pipe 2 as the monitoring measurement object have a predetermined relationship, and therefore the proximity distance at the temperature around the electromagnetic coil 16. , The pressing force on the pipe 2 can be obtained.

  Next, a sensor holding device and a sensor holding method according to each embodiment of the present invention will be described.

[First Embodiment]
FIG. 8 is a configuration diagram showing a configuration of a first sensor holding device 10A which is an example of the sensor holding device according to the first embodiment of the present invention.

  The first sensor holding device 10 </ b> A includes a sensor holding unit 12, and a first holding state monitoring circuit 21 </ b> A and a power supply circuit 22 as a monitoring unit that monitors (monitors) the holding state of the sensor holding unit 12.

  The first holding state monitoring circuit 21A is an example of the holding state monitoring circuit 21. For example, as shown in FIG. 8, a high frequency power supply 26 that supplies an excitation current (high frequency signal) If to the electromagnet coil 16, and a power supply A coupler 27 that superimposes the excitation current If on the excitation current Ic supplied from the DC constant current power supply 35 of the circuit 22 to the electromagnet coil 16, and a frequency lower than a predetermined frequency is cut off and a high frequency component of the high frequency power supply 26 is allowed to pass. A first filter 28, an AC voltage measuring device 29 that measures the voltage value of the signal output from the first filter 28, and a second that passes only the DC component without passing the high-frequency component of the high-frequency power source 26. A filter 30 and a DC voltage measuring device 31 that measures a voltage value of a signal output from the second filter 30 are provided.

  The power supply circuit 22 supplies an arbitrary exciting current Ic to the electromagnet coil 16, and is composed of a DC constant current power supply 35 that can supply a constant current even if the load (resistance, etc.) of the electromagnet coil 16 fluctuates. The

  Next, a sensor holding method in the first sensor holding device 10 </ b> A, that is, a method for calculating and adjusting a pressing force to the pipe 2 that is a monitoring measurement object will be described.

FIG. 9 is an explanatory diagram showing waveforms measured at the measurement points P _{A to} P _D shown in FIG. 8, and FIG. 9 (A), FIG. 9 (B), FIG. 9 (C) and FIG. D), respectively, the measurement point _{P a,} P B, is an explanatory diagram showing a waveform measured by _{P C} and _{P D.}

  The waveform shown in FIG. 9A is generated in the electromagnet coil 16 in a state where the excitation current Ic from the DC constant current power supply 35 and the excitation current If from the high frequency power supply 26 are applied to the electromagnet coil 16 in a superimposed manner. It is a voltage waveform. That is, the DC component (DC voltage waveform) of the voltage generated in the electromagnet coil 16 shown in FIG. 9D is changed to the high frequency (AC) component (high frequency) of the voltage generated in the electromagnet coil 16 shown in FIG. The voltage waveform is a superimposed voltage waveform.

In the state where the excitation current Ic supplied from the DC constant current power supply 35 to the magnet coil 16 and the excitation current If from the high frequency power supply 26 are applied in a superimposed manner, the voltage waveform at the measurement point P _B is as shown in FIG. As shown in B), a waveform in which an AC component (high frequency component) is superimposed on a DC component is obtained.

  In calculating the pressure (hereinafter simply referred to as “pressing force”) by which the sensor holding unit 12 of the first sensor holding device 10A presses the sensor against the monitoring measurement object (pipe 2), first, as preparation, an electromagnet The relationship between the temperature T around the coil 16 and the conductor resistance Rc of the electromagnet coil 16 (resistance characteristic), and the relationship between the proximity distance G at different ambient temperatures and the voltage (electromagnet voltage) Vfs at both ends of the electromagnet coil 16 (proximity) The relationship (pressing force characteristic) between the distance characteristic) and the proximity distance G and the pressing force F to the monitoring measurement object (pipe 2) is obtained in advance.

  10 to 12 are explanatory diagrams (graphs) for explaining various characteristics obtained in advance, FIG. 10 is an explanatory diagram for explaining the resistance value characteristics of the electromagnetic coil 16, and FIG. 11 is for explaining the proximity distance characteristics. FIG. 12 is an explanatory diagram for explaining the pressing force characteristics.

  In FIG. 10, the vertical axis represents the conductor resistance Rc indicating the resistance when the electromagnet coil 16 is conductive, and the horizontal axis represents the temperature T indicating the ambient temperature of the electromagnet coil 16, and the relationship between the conductor resistance Rc and the temperature T is expressed. Has been. The conductor resistance Rc is approximated as a linear function of temperature T (Rc = A1 · T + B1). Here, the coefficient A1 is an integer other than 0, the coefficient B1 is an integer, and generally A1 and B1 are positive integers.

  The conductor resistance Rc of the electromagnetic coil 16 can be obtained by obtaining the measured value of the DC voltage Vd measured by the DC voltage measuring device 31 of the first holding state monitoring circuit 21A. If the information of the resistance value characteristic of the electromagnetic coil 16 is obtained, the temperature T at the conductor resistance Rc is obtained from the resistance value characteristic of the electromagnetic coil 16 and the obtained conductor resistance Rc. Can do.

  FIG. 11A is an explanatory diagram showing the proximity distance characteristic at the temperature T. The proximity distance G is taken on the vertical axis, and the electromagnet voltage Vfs of the electromagnet coil 16 is taken on the horizontal axis. The relationship is expressed. Here, the proximity distance G is approximated as a linear function of temperature T (G = Ac (T) · Vfs + Bc (T)). Here, the temperature T is, for example, n (n is a natural number of 2 or more) different temperatures T1, T2,..., Tn, and the coefficient Ac (T) and the coefficient Bc (T) are It is a function.

  FIG. 11B is an explanatory diagram showing the relationship between the coefficient Ac and the temperature T, and FIG. 11C is an explanatory diagram showing the relationship between the coefficient Bc and the temperature T.

  In FIG. 11B, the coefficient Ac is plotted on the vertical axis and the temperature T is plotted on the horizontal axis, and the relationship between the coefficient Ac and the temperature T is represented. As shown in FIG. 11 (B), the function Ac (T) has a downward-sloping relationship, that is, the coefficient Ac decreases as the temperature T increases. In FIG. 11C, the relationship between the coefficient Bc and the temperature T is shown with the coefficient Bc on the vertical axis and the temperature T on the horizontal axis. As shown in FIG. 11C, the function Bc (T) is in a downward-sloping relationship, that is, the coefficient Bc decreases as the temperature T increases.

  In the first holding state monitor circuit 21A, the measured value of the electromagnet voltage Vfs measured by the AC voltage measuring device 29 can be obtained. Therefore, if there is information on the proximity distance characteristic, the measured value is measured by the DC voltage measuring device 31. The proximity distance G can be obtained using the proximity distance characteristic at the temperature obtained from the DC voltage Vd and the resistance value characteristic of the electromagnet coil 16 and the measured value of the electromagnet voltage Vfs.

  In FIG. 12, the relationship between the pressing force F and the proximity distance G is shown with the pressing force F pressing the sensor against the monitoring measurement object (pipe 2) on the vertical axis and the proximity distance G on the horizontal axis. . The pressing force F is approximated as a linear function (F = Ag · G + Bg) of the proximity distance G. Here, the coefficient Ag is an integer other than 0 and the coefficient Bg is an integer. In general, Ag is a negative integer and Bg is a positive integer.

  Since the first holding state monitoring circuit 21A can determine the proximity distance G, if there is information on the pressing force characteristics, the pressing force at the proximity distance G determined from the determined proximity distance G and the pressing force characteristics is determined. be able to.

  As described above, if the measured values of the electromagnet voltage Vfs and the DC voltage Vd of the electromagnet coil 16 are obtained by obtaining the resistance value characteristic, proximity distance characteristic and pressing force characteristic of the electromagnet coil 16 in advance, the electromagnet coil It is possible to calculate the ambient temperature of 16, the proximity distance G at a predetermined temperature, and the pressing force in the case of the proximity distance G. That is, the pressing force can be monitored by measuring the electromagnet voltage Vfs and the DC voltage Vd of the electromagnet coil 16.

  In the first sensor holding device 10A, information necessary to calculate the pressing force for pressing the sensor held by the sensor holding unit 12 against the pipe 2 includes the resistance value characteristic, the proximity distance characteristic, and the pressing force of the electromagnetic coil 16 in advance. It can be obtained by obtaining the characteristics and by the operator of the first sensor holding device 10A performing the following steps.

  First, the operator uses a certain access device to bring the first sensor holding device 10A close to the monitored object such as the pipe 2 and closes the switch SW (switches to the ON state). The set DC current (excitation current Ic) is supplied to the electromagnetic coil 16 to attract the sensor holding unit 12. However, in an environment where a person can access, the person may bring the first sensor holding device 10 </ b> A closer to the pipe 2 instead of the access device. Thereafter, the operator reads the voltage value indicated by the DC voltage measuring device 31 and measures the DC voltage Vd across the electromagnet coil 16.

  Subsequently, the high frequency power supply 26 is activated, the switch SW is opened (switched to the OFF state), and the high frequency signal (excitation current If) is superimposed on the line supplying the direct current to the electromagnet coil 16. Then, the voltage value indicated by the AC voltage measuring device 29 is read. That is, the AC voltage (electromagnet voltage) Vfs across the electromagnet coil 16 is measured.

  When the measurement of the DC voltage Vd and the electromagnet voltage Vfs is completed, the resistance value characteristic, the proximity distance characteristic, the pressing force characteristic, and the electromagnet voltage Vfs and DC of the electromagnet coil 16 obtained by measurement are obtained. Using the voltage Vd, the temperature around the electromagnet coil 16, the proximity distance G at the temperature around the electromagnet coil 16, and the pressing force at the proximity distance G can be calculated.

  Moreover, if the pressure (pressing force) which presses the sensor held by the sensor holding unit 12 against the pipe 2 as the monitoring measurement object can be calculated, the pressing force can be monitored. Furthermore, the pressing force can be increased or decreased, that is, the pressing force can be controlled depending on whether the calculated pressing force is larger or smaller than the required pressing force.

  The pressing force in the first sensor holding device 10A is controlled by increasing or decreasing the excitation current Ic supplied from the DC constant current power source 35 to the electromagnet coil 16. Specifically, when the current pressing force is stronger than the required pressing force and it is desired to weaken the pressing force to the pipe 2, the exciting current Ic supplied from the DC constant current power source 35 to the electromagnet coil 16 is decreased. On the other hand, when the current pressing force is weaker than the required pressing force and it is desired to increase the pressing force to the pipe 2, the exciting current Ic supplied from the DC constant current power source 35 to the electromagnet coil 16 is increased.

  According to the first sensor holding device 10A and the sensor holding method applied to the first sensor holding device 10A, the electromagnet voltage Vfs which is a high frequency (alternating current) component of the voltage generated in the electromagnet coil 16 and the direct current which is a direct current component. The voltage Vd can be measured. Therefore, by using the electromagnet voltage Vfs and DC voltage Vd obtained by measurement and the resistance value characteristic, proximity distance characteristic, and pressing force characteristic of the electromagnet coil 16 obtained in advance, the user can use the sensor holding unit 12. The pressing force to the monitoring measurement object (pipe 2) can be obtained.

  Further, according to the sensor holding method applied in the first sensor holding device 10A and the first sensor holding device 10A, the pressing force of the sensor holding unit 12 on the monitoring measurement object can be obtained, so that the user can Since the exciting current Ic supplied from the DC constant current power source 35 to the electromagnet coil 16 can be increased or decreased according to the obtained pressing force, the strength of the pressing force can be easily controlled.

  Furthermore, since the calculation of the pressing force on the monitoring measurement object and the strength control of the pressing force can be performed remotely, the environment where the monitoring measurement object exists can be controlled in the atmosphere (temperature, Even under conditions where the radiation) changes significantly, it can be applied.

  Furthermore, since the number of cables on the side of the sensor holding unit 12 (in the isolation chamber 1 shown in the figure) does not increase with respect to the conventional sensor holding device, the operation of attaching the sensor remotely using an access device such as a manipulator Even if this occurs, the accessibility equivalent to that of the conventional sensor holding device can be maintained.

[Second Embodiment]
FIG. 13 is a configuration diagram showing a configuration of a second sensor holding device 10B which is an example of a sensor holding device according to the second embodiment of the present invention.

  The second sensor holding device 10B calculates a pressing force for calculating the pressure (pressing force) for pressing the sensor held by the sensor holding unit 12 against the pipe 2 as the monitoring measurement object with respect to the first sensor holding device 10A. The controller 45 as a pressing force control unit that controls the pressing force calculated by the processing unit and the pressing force calculation processing unit to be the specified pressing force, a digital / analog converter (hereinafter referred to as “analog signal”). "D / A converter" and indicated as "D / A" in the figure) 46 and an analog / digital converter (hereinafter referred to as "A / D converter") that converts an analog signal into a digital signal. It is different in that it further includes 47, but the other points are not substantially different.

  Therefore, in the present embodiment, the description will focus on the points that are substantially different from the first sensor holding device 10A, and the components that are substantially the same as those of the first sensor holding device 10A have the same reference numerals. The description is omitted.

  In the second sensor holding device 10B, the pressing force calculation processing unit that calculates the pressing force and the pressing force calculated by the pressing force calculation processing unit become the specified pressing force with respect to the first sensor holding device 10A. And a controller 45 as a pressing force calculation processing unit and a pressing force calculation processing unit, and a D / A converter 46 and an A / D converter 47, for example. To do. Here, the D / A converter 46 and the A / D converter 47 are interfaces between the controller 45 and the first holding state monitor circuit 21A.

  The controller 45 serving as the pressing force calculation processing unit calculates an A / A voltage between the electromagnet voltage Vfs of the electromagnet coil 16 measured by the measurement AC voltage measuring device 29 and the DC voltage Vd measured by the DC voltage measuring device 31 as analog signals. Each of them is converted into a digital signal and taken in via the D converter 47. The controller 45 has information on the resistance value characteristic, the proximity distance characteristic, and the pressing force characteristic of the electromagnet coil 16 that has been obtained in advance, and the acquired digital signal of the electromagnet voltage Vfs (digital signal) and the DC voltage Vd Then, the pressing force to the pipe 2 is calculated using the resistance value characteristic, proximity distance characteristic and pressing force characteristic of the electromagnet coil 16 obtained in advance.

  Further, the controller 45 as a pressing force control unit outputs a control command (digital signal) for controlling the pressure (pressing force) pressing the sensor held by the sensor holding unit 12 against the pipe 2 to the specified pressing force. The A converter 46 converts the digital signal into an analog signal, and supplies it to the power supply circuit 22 and the first holding state monitor circuit 21A.

  More specifically, the controller 45 transmits an output current command to the DC constant current power supply 35 of the power supply circuit 22 to control the excitation current Ic. Further, the controller 45 controls the excitation current If by transmitting an output frequency command and an output voltage command to the high frequency power supply 26 of the first holding state monitoring circuit 21A. The controller 45 controls the exciting current Ic and the exciting current If, whereby the pressing force to the pipe 2 is controlled.

  Next, a sensor holding method in the second sensor holding device 10 </ b> B, that is, a method for calculating and adjusting a pressing force to the pipe 2 that is a monitoring measurement object will be described.

  In the second sensor holding device 10B, the pressing force calculation procedure for calculating the pressure (pressing force) for pressing the sensor held by the sensor holding unit 12 against the pipe 2 and the adjustment (control) procedure for adjusting (controlling) are as follows, for example: The steps (1) to (8) shown in FIG.

  (1) The second sensor holding device 10B is brought close to the monitoring measurement object such as the pipe 2 and the switch SW is closed (switched to the ON state), and the DC current (excitation current Ic) set from the power supply circuit 22 is applied. The electromagnet coil 16 is supplied, and the sensor holding part 12 is attracted to the pipe 2. The operation of bringing the second sensor holding device 10B closer to the monitoring measurement object is performed using some access device. However, in an environment where a person can access, a person may go instead of the access device.

  (2) The measurement data of the DC voltage Vd across the electromagnet coil 16 measured by the DC voltage measuring device 31 is taken into the controller 45 via the A / D converter 47 serving as an interface.

  (3) The controller 45 calculates the conductor resistance Rc of the electromagnet coil 16 from the measurement data of the DC voltage Vd measured by the acquired DC voltage measuring device 31, and calculates the calculated conductor resistance Rc and the temperature T around the electromagnet coil 16. The temperature T around the electromagnet coil 16 is calculated using information of the approximate expression (resistance characteristic of the electromagnet coil 16: Rc = A1 · T + B1).

  (4) The high-frequency power supply 26 is activated, the switch SW is opened (switched to the OFF state), and a high-frequency signal (excitation current If) is superimposed on the line supplying the direct current to the electromagnet coil 16.

  (5) The measurement data of the AC voltage (electromagnet voltage) Vfs across the electromagnet coil 16 measured by the AC voltage measuring device 29 is taken into the controller 45 through the A / D converter 47 serving as an interface.

  (6) The controller 45 uses the proximity distance characteristics obtained in advance, the AC voltage (electromagnet voltage) Vfs measured by the acquired AC voltage measuring device 29, and the calculated temperature T around the conductor resistance Rc. Thus, the proximity distance G is calculated from an approximate expression (proximity distance characteristic) indicating the relationship between the electromagnet voltage Vfs at the temperature T and the proximity distance G.

  (7) The controller 45 calculates the pressing force F in the case of the proximity distance G using the pressing force characteristics obtained in advance and the calculated proximity distance G.

  (8) The controller 45 compares the calculated value of the pressing force F to the sensor (calculated value) with the set value of the sensor pressing force (set value). If the calculated value is larger than the set value as a result of the comparison, a command to decrease the current value supplied to the electromagnet coil 16 via the D / A converter 46 is output to the DC constant current power supply 35 of the power supply circuit 22. Conversely, if the calculated value is smaller than the set value, a command to increase the current value supplied to the electromagnet coil 16 is output to the DC constant current power supply 35 of the power supply circuit 22.

  Thereafter, the second sensor holding device 10B is configured so that the sensor holding unit 12B is continuously repeated by repeating the processes of steps (2), (3), (5), (6), (7), and (8). Even if the ambient temperature of the pipe 2 as a monitoring and measuring object to which is attached changes greatly, the controller 45 can always maintain the pressing force within a predetermined range.

  According to the sensor holding method applied in the second sensor holding device 10B and the second sensor holding device 10B, the controller 45 as the pressing force calculation unit uses a high frequency (alternating current) component of the voltage generated in the electromagnetic coil 16. A certain electromagnet voltage Vfs and a direct current voltage Vd which is a direct current component are measured, and the electromagnet voltage Vfs and direct current voltage Vd obtained by the measurement, and the resistance value characteristic, proximity distance characteristic and pressing force of the electromagnet coil 16 which are obtained in advance. Since the pressing force of the sensor holding unit 12 on the monitoring measurement object (pipe 2) can be obtained using the characteristics, the pressing force can be monitored.

  Further, according to the sensor holding method applied in the second sensor holding device 10B and the second sensor holding device 10B, the controller 45 as the pressing force control unit obtains the calculated pressing force and the set pressing force. In comparison, the excitation current Ic supplied from the DC constant current power source 35 to the electromagnet coil 16 can be increased or decreased according to the result, so that the strength of the pressing force can be easily controlled.

  In the description of the present embodiment described above, the second sensor holding device 10B includes, as an example, a D / A converter 46 and an A / D that serve as an interface between the controller 45 and the first holding state monitoring circuit 21A. Although the converter 47 is provided, the controller 45 or the first holding state monitor circuit 21A may be provided with the interface.

  In the description of the present embodiment described above, it has been described that the controller 45 has information on the resistance value characteristic, the proximity distance characteristic, and the pressing force characteristic of the electromagnetic coil 16 obtained in advance. The information of the resistance value characteristic, the proximity distance characteristic, and the pressing force characteristic may be held in a storage area that can be read by the controller 45, and the controller 45 does not necessarily have to have the information.

  Further, the second sensor holding device 10B includes a pressing force calculation processing unit and a pressing force control unit. However, the second sensor holding device 10B does not necessarily include both the pressing force calculation processing unit and the pressing force control unit. Absent. For example, if the computer does not control the pressing force, such as controlling the pressing force after the operator of the second sensor holding device 10B determines the calculation result of the pressing force, a pressing force control unit is provided. It is also possible to configure a sensor holding device that does not.

[Third Embodiment]
FIG. 14 is a configuration diagram showing a configuration of a third sensor holding device 10C which is an example of a sensor holding device according to the third embodiment of the present invention.

  The third sensor holding device 10C has a second holding state monitoring circuit 21B instead of the first holding state monitoring circuit 21A with respect to the second sensor holding device 10B, and the controller 45 has. It differs in the content of the information, but the other points are not substantially different. Therefore, in the present embodiment, the description will focus on the points that are substantially different from the second sensor holding device 10B, and the components that are substantially the same as those of the second sensor holding device 10B have the same reference numerals. The description is omitted.

  The third sensor holding device 10C includes a second holding state monitoring circuit 21B instead of the first holding state monitoring circuit 21A with respect to the second sensor holding device 10B. That is, the third sensor holding device 10C is different from the second sensor holding device 10B in the configuration of a monitoring unit that monitors (monitors) the holding state of the sensor holding unit 12.

  The second holding state monitor circuit 21B has a voltage output from the high frequency power supply 26 in place of the AC voltage measuring device 29 provided in the first holding state monitor circuit 21A with respect to the first holding state monitor circuit 21A. A phase difference detector 49 as a phase difference measuring unit that measures a phase difference from the electromagnet voltage of the electromagnet coil 16 and a first voltage that is passed when the voltage output from the high frequency power supply 26 is input to the phase difference detector 49. A filter (high-pass filter) 28 is further provided.

  That is, in the third sensor holding device 10C including the second holding state monitor circuit 21B, the high frequency power source is used as information for obtaining the proximity distance G between the electromagnet coil 16 and the pipe 2 which is an example of the monitoring measurement object. The phase difference between the voltage output from the electromagnetic wave 26 and the electromagnet voltage of the electromagnet coil 16 is used.

  FIG. 15 is an explanatory diagram showing the relationship (proximity distance characteristic) between the phase difference P and the proximity distance G. The vertical axis indicates the proximity distance G, the horizontal axis indicates the voltage output from the high-frequency power supply 26 and the electromagnet of the electromagnetic coil 16. The relationship between the proximity distance G and the phase difference P is expressed by taking the phase difference from the voltage.

  As shown in FIG. 15, the relationship between the phase difference P and the proximity distance G has a correlation and can be obtained in advance. Therefore, in the third sensor holding device 10C, the second sensor holding device 10B. The proximity distance G is determined using the relationship between the phase difference P and the proximity distance G (FIG. 15) instead of the relationship between the electromagnet voltage Vfs and the proximity distance G used in FIG.

  Next, a sensor holding method in the third sensor holding device 10 </ b> C, that is, a method for calculating and adjusting a pressing force to the pipe 2 as a monitoring measurement object will be described.

  Note that the sensor holding method in the third sensor holding device 10C is similar to the sensor holding method in the second sensor holding device 10B in determining the proximity distance G to the pipe 2 that is an example of the monitoring measurement object. Although it differs in whether an electromagnet voltage is used or a phase difference is used, it is not substantially different in other points. That is, among steps (1) to (8) described in the second embodiment, steps (5) and (6) are different, but the other steps are not substantially different. Therefore, in the following description, steps (5) and (6) that are different from the sensor holding method in the second sensor holding device 10B will be described, and descriptions of other steps that are not different will be omitted.

  Steps (5) and (6) of the pressing force calculation procedure and the adjustment (control) procedure in the third sensor holding device 10C are as follows.

  (5) The phase difference detector 49 takes in the voltage output from the high frequency power supply 26 via the first filter 28 and the voltage across the electromagnetic coil 16 via the first filter 28, and calculates the phase difference time value. measure. The controller 45 loads the phase difference measurement data (phase difference time value) measured by the phase difference detector 49 into the controller 45 via the A / D converter 47 serving as an interface.

  (6) The controller 45 obtains information on the proximity distance characteristics (an approximate expression indicating the relationship of the proximity distance G with respect to the phase difference P) obtained in advance, information on the captured phase difference P, and the calculated conductor resistance Rc. Using the ambient temperature T, the proximity distance G is calculated from an approximate expression (proximity distance characteristic) indicating the relationship between the phase difference P at the temperature T and the proximity distance G.

  According to the sensor holding method applied in the third sensor holding device 10C and the third sensor holding device 10C, used in the sensor holding method applied in the second sensor holding device 10B and the second sensor holding device 10B. Information different from the information to be transmitted, that is, the phase difference between the voltage output from the high-frequency power supply 26 and the voltage across the electromagnetic coil 16, and the information indicating the relationship between the phase difference P and the proximity distance G, The same effect as that of the sensor holding method applied in the sensor holding device 10B and the second sensor holding device 10B can be obtained.

  Note that the third sensor holding device 10C shown in FIG. 14 includes a second holding state monitoring circuit 21B instead of the first holding state monitoring circuit 21A included in the second sensor holding device 10B. However, the present invention may be applied not to the second sensor holding device 10B but to the first sensor holding device 10A. That is, the third sensor holding device 10C may include the second holding state monitoring circuit 21B instead of the first holding state monitoring circuit 21A included in the first sensor holding device 10A.

[Fourth Embodiment]
FIG. 16 is a configuration diagram showing a configuration of a sensor holding device 10D which is an example of a sensor holding device according to the fourth embodiment of the present invention.

  The fourth sensor holding device 10D is different in that the sensor holding unit 51 is provided instead of the sensor holding unit 12 provided in the other (first, third, fifth) sensor holding devices 10A, 10B, 10C, and 10E. However, other points are not substantially different. Therefore, in the present embodiment, the description will focus on the points that are substantially different from the other (first, third, fifth) sensor holding devices 10A, 10B, 10C, 10E, and the other (first, third, fifth). ) Are substantially the same as the sensor holding devices 10A, 10B, 10C, and 10E, and the description thereof is omitted.

  For example, the fourth sensor holding device 10D shown in FIG. 16 includes a sensor holding unit 51 instead of the sensor holding unit 12 included in the third sensor holding device 10C. The sensor holding unit 51 further includes a permanent magnet 52 with respect to the sensor holding unit 12 that is applied to the pipe 2 as the monitoring measurement object by applying the electromagnet coil 16, and two different types of electromagnet and permanent magnet 52 are provided. The magnet 2 can be adsorbed to the pipe 2.

  Next, a sensor holding method in the fourth sensor holding device 10D will be described by taking the fourth sensor holding device 10D shown in FIG. 16 as an example.

  The sensor holding method in the fourth sensor holding device 10D shown in FIG. 16 differs from the sensor holding method in the third sensor holding device 10C in the suction method of the sensor holding unit 51, that is, step (1). However, the other steps are not substantially different. Therefore, in the following description, step (1) different from the sensor holding method in the third sensor holding device 10C will be described, and description of other steps that are not different will be omitted.

  In the sensor holding method in the fourth sensor holding device 10D, that is, the method for calculating and adjusting the pressing force on the pipe 2 to be monitored and measured, in step (1), the sensor holding unit 51 is monitored for the pipe 2 and the like. Adsorb to the measurement object. When the sensor holding unit 51 is attracted to the pipe 2, the controller 45 first causes the current supplied to the electromagnet coil 16 to flow in the opposite direction with respect to the attractive force of the permanent magnet 52, and the sensor holding unit 51 as a whole. The suction force is reduced, and then the suction force of the sensor holding unit 51 as a whole is gradually increased to bring the sensor holding unit 51 closer to the pipe 2.

  According to the sensor holding method applied in the fourth sensor holding device 10D and the fourth sensor holding device 10D, the other sensor holding devices 10A, 10B, 10C, 10E and the other sensor holding devices 10A, 10B, 10C, Similar to the sensor holding method applied in 10E, the pressing force can be monitored and controlled to be held within a desired range.

  Further, the fourth sensor holding device 10D includes the sensor holding unit 51 including the electromagnet coil 16 as an electromagnet in addition to the permanent magnet 52, and thus cannot be achieved by a conventional sensor holding device including only the permanent magnet 52. The adsorption force can be adjusted easily and remotely. That is, according to the fourth sensor holding device 10 </ b> D, the work of attaching / detaching the sensor holding unit 51 to / from the monitoring measurement object such as the pipe 2 becomes easier than the conventional sensor holding device including only the permanent magnet 52.

  Further, the fourth sensor holding device 10D includes the sensor holding unit 51 including the permanent magnet 52 in addition to the electromagnet coil 16 serving as an electromagnet, so that the excitation current Ic supplied to the electromagnet coil 16 can be changed from the conventional or other sensors. The holding devices 10A, 10B, 10C, and 10E can be kept smaller. That is, in the fourth sensor holding device 10D, the allowable current of the power supply circuit 22 that supplies the excitation current Ic to the electromagnet coil 16 and the electromagnet coil 16 (more specifically, the wiring 13a that constitutes the electromagnet coil 16) is suppressed to be smaller. Can do.

  In the fourth sensor holding device 10D, the allowable current of the power supply circuit 22 and the electromagnet coil 16 can be reduced as compared with the conventional or other sensor holding devices 10A, 10B, 10C, and 10E. The wiring 13a of the coil 16 can be thinned, and the amount of heat generated by the electromagnet coil 16 can be reduced.

  The fourth sensor holding device 10D is not limited to the fourth sensor holding device 10D shown in FIG. That is, any sensor holding device including the sensor holding unit 12 may be used, and not only the third sensor holding device 10C, but also the first sensor holding device 10A and the second sensor holding device 10B described above and a fifth described later. It is applicable to the sensor holding device 10E.

[Fifth Embodiment]
FIG. 17 is a configuration diagram showing a configuration of a fifth sensor holding device 10E which is an example of a sensor holding device according to the fifth embodiment of the present invention.

  The fifth sensor holding device 10E includes a third holding state monitor circuit 21C instead of the second holding state monitor circuit 21B, and the controller 45 has a third sensor holding device 10C. It differs in the content of the information, but the other points are not substantially different. Therefore, in the present embodiment, the description will focus on the points that are substantially different from the third sensor holding device 10C, and the components that are substantially the same as those of the third sensor holding device 10C are denoted by the same reference numerals. The description is omitted.

  The fifth sensor holding device 10E includes a sensor holding unit 12, and a third holding state monitoring circuit 21C and a power supply circuit 22 as a monitoring unit that monitors (monitors) the holding state of the sensor holding unit 12. In other words, the fifth sensor holding device 10E is different from the third sensor holding device 10C in the configuration of a monitoring unit that monitors (monitors) the holding state of the sensor holding unit 12.

  The third holding state monitor circuit 21 </ b> C has a frequency variable function for changing the frequency of the high frequency power supply 26 and the first holding state monitor circuit 21 </ b> B that is passed when input to the phase difference detector 49. And a passband variable function for changing the band of the filter (high-pass filter) 28.

  In the fifth sensor holding device 10E having the third holding state monitoring circuit 21C, the frequency of the high frequency power supply 26 is the same as the other sensor holding devices 10A to 10D having the other holding state monitoring circuits 21A and 21B. Since it can be changed to a plurality of different frequencies instead of being fixed, a plurality of different frequencies can be used even when the structure (thickness or material) and state around the monitored object such as the pipe 2 are changed. If the measurement is performed with the power supply frequency of the high-frequency power supply 26 set, a signal having a high frequency sensitivity can be selected and extracted from a plurality of data.

  The controller 45 in the fifth sensor holding device 10E gives a frequency change command for changing the frequency of the high-frequency power source 26 to the controllers 45 in the other sensor holding devices 10A to 10D to variably control the frequency of the high-frequency power source 26. A frequency control unit, and a signal passband control unit that variably controls the frequency band of the signal passing through the first filter 28 by giving a band change command for changing the frequency band of the signal passing through the first filter 28 Prepare.

  The controller 45 serving as the frequency variable control unit and the signal passband variable control unit sends a frequency change command for changing the frequency of the high frequency power supply 26 and a signal passing through the first filter 28 to the third holding state monitor circuit 21C. By giving a band change command for changing the frequency band, the frequency of the high frequency power supply 26 and the signal pass band of the first filter 28 in the third holding state monitor circuit 21C can be changed.

  FIG. 18 shows the relationship between the frequency f of the high-frequency power source 26, the phase difference P detected by the phase difference detector 49, and the proximity distance G, which is the distance between the monitoring measurement object (conductor) such as the pipe 2 and the electromagnetic coil 16. It is explanatory drawing shown. More specifically, FIG. 18A is an explanatory diagram showing the relationship of the proximity distance G to the phase difference P when the frequency f is changed, and FIG. 18B is a diagram when the proximity distance G is changed. It is explanatory drawing which shows the relationship of the phase difference P with respect to the frequency f. FIG. 18 shows a case where the temperature T is constant.

  The diagram (graph) shown in FIG. 18A and the diagram (graph) shown in FIG. 18B show the same content from different viewpoints, and the frequency f, phase difference P, and proximity distance. G indicates that there is a predetermined relationship. For example, as shown in FIG. 18A, the proximity distance G is approximated as a linear function of the phase difference P (G = Ap (f) · P + Bp (f)). Here, the frequency f is, for example, n (n is a natural number of 2 or more) different frequencies f1, f2,..., Fn, and the coefficient Ap (f) and the coefficient Bp (f) It is a function.

  The relationship between the phase difference P and the proximity distance G is determined in advance by measuring the proximity distance G when the phase difference P is sequentially changed at a certain frequency (for example, f1), and then sequentially changing the frequency (for example, f2, .., Fn) can be obtained by performing the same measurement. On the other hand, the relationship between the frequency f and the phase difference P is determined in advance by measuring the phase difference P when the frequency f is sequentially changed at a certain proximity distance (for example, G1), and then sequentially changing the proximity distance (for example, G2,..., Gn) can be obtained by performing the same measurement.

  Next, a sensor holding method in the fifth sensor holding device 10E will be described.

  In the sensor holding method in the fifth sensor holding device 10E, the controller 45 changes the frequency of the high-frequency power source 26 when the controller 45 captures a signal as compared with the sensor holding method in the third sensor holding device 10C. The difference is that the frequency band through which the first filter 28 passes is changed according to the changed frequency of the high-frequency power supply 26, but the other steps are not substantially different. That is, among steps (1) to (8) described above, step (6) is different, but the other steps are not substantially different. Therefore, in the following description, steps that are different from the sensor holding method in the third sensor holding device 10C will be described, and descriptions of other steps that are not different will be omitted.

  Step (6) of the pressing force calculation procedure and the adjustment (control) procedure in the fifth sensor holding device 10E is as follows.

  (6) The controller 45 obtains the information on the relationship between the phase difference P and the proximity distance G or the relationship between the frequency f and the phase difference P that has been obtained in advance, the information on the captured phase difference P, and the controller 45 The proximity distance G is calculated using information on the frequency f of the high-frequency power source 26 being controlled.

  For example, if the captured phase difference P value is P1 and the frequency f value of the high frequency power supply 26 is f1, the controller 45 provides information indicating the relationship between the phase difference P and the proximity distance G to the proximity distance G. When used for the calculation, the proximity distance G that becomes the phase difference P1 can be obtained using information indicating the relationship between the phase difference P and the proximity distance G in the case of the frequency f1. On the other hand, when the information on the relationship between the frequency f and the phase difference P is used to calculate the proximity distance G, the information indicating the relationship between the frequency f and the phase difference P at the proximity distances G1, G2,. It is possible to determine which of the proximity distances G1, G2,..., Gn is the proximity distance G at which the phase difference is P1 in the case of f1.

  In addition, when the frequency f of the high frequency power supply 26 is changed, the processes of steps (5) to (8) are performed at the changed frequency.

  According to the sensor holding method applied in the fifth sensor holding device 10E and the fifth sensor holding device 10E, the same as the sensor holding method applied in the third sensor holding device 10C and the third sensor holding device 10C. In addition to the effects similar to those of the second sensor holding device 10B and the sensor holding method applied to the second sensor holding device 10B, the pressing force can be increased by changing the frequency f of the high frequency power source 26. Since it can be obtained, even when the surrounding structure (thickness or material) of the monitoring measurement object and the surrounding state change, only a signal having a sensitive frequency among the different frequencies f can be selected and extracted. Can do.

  Note that the fifth sensor holding device 10E shown in FIG. 17 includes a third holding state monitor circuit 21C instead of the second holding state monitor circuit 21B included in the third sensor holding device 10C. However, instead of the first holding state monitoring circuit 21A, a third holding state monitoring circuit 21C may be provided. That is, for the first holding state monitor circuit 21A, the frequency variable function for changing the frequency of the high frequency power supply 26 and the band of the first filter (high-pass filter) 28 that is passed when input to the phase difference detector 49 are provided. You may comprise the 3rd holding | maintenance state monitor circuit 21C which further has the pass-band variable function to change.

  As described above, according to the sensor holding device 10 (10A to 10E) and the sensor holding method applied in the sensor holding device 10, the pressing force of the sensor holding units 12 and 51 on the monitoring measurement object (pipe 2) can be obtained. The exciting current Ic supplied from the DC constant current power source 35 to the electromagnet coil 16 can be increased or decreased according to the obtained pressing force, so that the strength of the pressing force can be easily controlled.

  In addition, since the calculation of the pressing force of the sensor holding units 12 and 51 on the monitoring measurement object and the control of the strength of the pressing force can be performed remotely, the environment in which the monitoring measurement object exists is an atmosphere in which no human can enter. In particular, the present invention can be applied even under conditions where the environment (temperature, radiation) changes significantly.

  Furthermore, since the number of cables on the sensor holding portions 12 and 51 side (in the room of the isolation chamber 1 shown in the figure) does not increase with respect to the conventional sensor holding device, the sensor can be remotely connected using an access device (manipulator or the like). Even if the attaching operation occurs, the same accessibility as that of the conventional sensor holding device can be maintained.

  It should be noted that the present invention is not limited to the above-described embodiment as it is, and can be implemented in various forms other than the above-described examples in the implementation stage, and various modifications can be made without departing from the spirit of the invention. Can be omitted, added, replaced, or changed. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

1 Isolation chamber 2 Piping (monitoring / measurement object)
3 Wall 10 (10A, 10B, 10C, 10D, 10E) Sensor holding device 11 Sensor 12 Sensor holding portion 13 (13a, 13b) Wiring 16 Electromagnetic coil 17 Iron core 18 Sensor fixture 20 Control panel 21 (21A, 21B, 21C) Holding state monitor circuit 22 Power supply circuit 23 Sensor signal processing circuit 26 High frequency power supply 27 Coupler 28 First filter 29 AC voltage measuring instrument 30 Second filter 31 DC voltage measuring instrument 32 Line 35 DC constant current power supply 36 High frequency power supply 38 Reference Waveform 39 Observation waveform 45 Controller 46 Digital / analog (D / A) converter 47 Analog / digital (A / D) converter 49 Phase difference detector 51 Sensor holding part 52 Permanent magnet 100 Conventional sensor holding apparatus 101 Sensor holding part 102 Sensor 104 Permanent magnet 105 Sensor probe 107 Sen Signal processing device 108 Electromagnet 109 DC constant current power supply

Claims (13)

A sensor holding unit that includes an electromagnetic coil that holds a sensor that is in contact with a monitoring or measurement object that is a monitoring or measurement object, and that generates a magnetic force by receiving an excitation current;
A direct current supply unit for supplying a direct current to the electromagnet coil;
A high-frequency current supply unit for supplying a high-frequency current to the electromagnet coil;
An alternating current component superimposing unit that superimposes a high frequency current supplied from the high frequency current supply unit on a direct current supplied from the direct current supply unit to the electromagnet coil;
An AC voltage measurement unit that extracts an AC component of a voltage signal at both ends of the electromagnet coil and measures an AC voltage;
A sensor holding apparatus comprising: a DC voltage measuring unit that extracts a DC component of a voltage signal at both ends of the electromagnet coil and measures a DC voltage. First information indicating the relationship between the conductor resistance of the electromagnetic coil and the ambient temperature of the electromagnetic coil, which is information obtained in advance prior to calculating the pressing force for pressing the sensor against the monitoring measurement object, a plurality of different information Second information indicating a relationship between an electromagnet voltage indicating a voltage at both ends of the electromagnet coil at a temperature and a proximity distance indicating a distance between the monitoring measurement object, the proximity distance and the sensor as the monitoring measurement object Third information indicating a relationship with the pressing force to be pressed, information on a DC current value supplied to the electromagnet coil by the DC current supply unit, information on a DC voltage value measured by the DC voltage unit, and the AC voltage AC voltage value information measured by the measurement unit, and the acquired first information, second information, third information, DC current value information, AC voltage information, and Based on said information of the DC voltage value, the sensor holding device according to claim 1, wherein said sensor characterized by including the monitor measuring a pressing force calculating a pressing force pressing the object calculation processing unit further. The sensor holding device according to claim 1, further comprising a pressing force control unit that controls a pressing force for pressing the sensor against the monitoring measurement object by increasing or decreasing a direct current supplied to the electromagnet coil. apparatus. A sensor holding unit that includes an electromagnetic coil that holds a sensor that is in contact with a monitoring or measurement object that is a monitoring or measurement object, and that generates a magnetic force by receiving an excitation current;
A direct current supply unit for supplying a direct current to the electromagnet coil;
A high-frequency current supply unit for supplying a high-frequency current to the electromagnet coil;
An alternating current component superimposing unit that superimposes a high frequency current supplied from the high frequency current supply unit on a direct current supplied from the direct current supply unit to the electromagnet coil;
The AC component of the voltage signal at both ends of the electromagnet coil and the voltage signal at both ends of the high-frequency current supply unit are extracted, and the extracted AC component of the voltage signal at both ends of the electromagnet coil and both ends of the high-frequency current supply unit A phase difference measuring unit for measuring a phase difference with the voltage signal of
A sensor holding apparatus comprising: a DC voltage measuring unit that extracts a DC component of a voltage signal at both ends of the electromagnet coil and measures a DC voltage. First information indicating the relationship between the conductor resistance of the electromagnetic coil and the ambient temperature of the electromagnetic coil, which is information obtained in advance prior to calculating the pressing force for pressing the sensor against the monitoring measurement object, a plurality of different information A second relationship between the phase difference between the AC component of the voltage signal at both ends of the electromagnet coil and the voltage signal at both ends of the high-frequency current supply unit and the proximity distance indicating the distance from the monitoring measurement object at the temperature of Information, third information indicating a relationship between the proximity distance and a pressing force pressing the sensor against the monitoring measurement object, information on a direct current value supplied to the electromagnet coil by the direct current supply unit, and the direct current The information of the DC voltage value measured by the voltage unit and the information of the AC voltage value measured by the AC voltage measurement unit are acquired, and the acquired first information, second information, third information, The apparatus further comprises a pressing force calculation processing unit that calculates a pressing force for pressing the sensor against the monitoring measurement object based on the DC current value information, the AC voltage information, and the DC voltage value information. The sensor holding device according to claim 4. The sensor holding device according to claim 4, further comprising a pressing force control unit that controls a pressing force for pressing the sensor against the monitoring measurement object by increasing or decreasing a direct current supplied to the electromagnet coil. apparatus. A frequency control unit that variably controls the frequency of the high-frequency current supplied by the high-frequency current supply unit;
A signal pass band control unit that variably controls the frequency band to be extracted from the AC component of the voltage signal at both ends of the electromagnet coil,
The pressing force calculation processing unit is information obtained in advance prior to calculating the pressing force for pressing the sensor against the monitoring measurement object, and the distance between the electromagnet voltage at different frequencies and the monitoring measurement object The fourth information indicating the relationship with the proximity distance indicating the frequency, the information on the frequency of the high-frequency current variably controlled by the frequency control unit, the acquired fourth information, and the information on the frequency of the high-frequency current 7. The proximity distance in the AC voltage value of the electromagnet voltage measured by the frequency of the high-frequency current and the AC voltage measurement unit is calculated based on the above. Sensor holding device. The sensor holding device according to claim 1, wherein the sensor holding unit further includes a permanent magnet. Means comprising an electromagnet coil that holds a sensor to be in contact with a monitoring / measuring object that is an object to be monitored or measured and generates a magnetic force upon receiving an excitation current, and supplies a DC current as the exciting current to the electromagnet coil Means for supplying a high-frequency current, means for superimposing a high-frequency current supplied from the means for supplying the high-frequency current on a direct current supplied to the electromagnet coil, and alternating current of voltage signals at both ends of the electromagnet coil Proximity indicating a distance from the monitoring measurement object having a known relationship with a pressing force for pressing the sensor against the monitoring measurement object using at least one of a component and a voltage signal at both ends of the means for supplying the high-frequency current Means for obtaining a physical quantity indicating a known relationship with respect to the distance, and extracting a DC component of a voltage signal at both ends of the electromagnetic coil, Means for calculating the pressing force using the physical quantity obtained by the means for obtaining a physical quantity indicating a known relationship with respect to the proximity distance and the known relation; and a means for calculating the pressing force. Means for controlling the pressing force so that the calculated pressing force falls within a preset range when the calculated pressing force is not within a preset range, and a sensor holding method using a sensor holding device comprising:
The means for supplying the high frequency current supplies the high frequency current to the electromagnet coil;
The means for superimposing the high-frequency current superimposes the high-frequency current supplied to the electromagnetic coil in the step of supplying the high-frequency current to the electromagnet coil from the direct current supplied from the means for supplying the direct current to the electromagnet coil. When,
The means for obtaining a physical quantity indicating a known relationship with respect to the proximity distance uses at least one of an AC component of a voltage signal at both ends of the electromagnetic coil and a voltage signal at both ends of the means for supplying the high-frequency current, and A physical quantity indicating a known relationship with respect to a proximity distance indicating a distance from the monitoring measurement object that is in a known relationship with a pressing force that presses the object to the monitoring measurement object. Retention method. The means for calculating the pressing force has the DC voltage value information of the voltage signal at both ends of the electromagnet coil measured by the means for measuring the DC voltage, and the DC supplied from the means for supplying the DC current to the electromagnet coil. Calculating a conductor resistance of the electromagnetic coil using current value information; and
Prior to calculating the pressing force for pressing the sensor against the monitoring / measuring object, the means for calculating the pressing force calculates information on the conductor resistance of the electromagnetic coil calculated in the step of calculating the conductor resistance of the electromagnetic coil. And obtaining the ambient temperature of the electromagnet coil using information indicating the relationship between the conductor resistance of the electromagnet coil and the ambient temperature of the electromagnet coil. The sensor holding method according to claim 9. The means for controlling the pressing force determines whether or not the pressing force calculated in the step of calculating the pressing force is within a preset range. If the pressing force is not within the preset range, The sensor holding method according to claim 9, further comprising a step of changing the pressing force by changing a direct current supplied to the electromagnet coil so as to be within a range. The step of obtaining a physical quantity indicating a known relationship with respect to the proximity distance is configured such that when the physical quantity indicating the known relationship with respect to the proximity distance is an AC voltage of a voltage signal at both ends of the electromagnetic coil, both ends of the electromagnetic coil Using the information on the AC voltage value of the voltage signal and the information indicating the relationship between the AC voltage of the voltage signal at both ends of the known electromagnetic coil and the proximity distance, the pressing force has a known relationship. The sensor holding method according to claim 9, wherein the sensor holding method is a step of obtaining a proximity distance. The step of obtaining a physical quantity indicating a known relationship with respect to the proximity distance includes the step of determining the physical quantity indicating the known relationship with respect to the proximity distance between an AC component of a voltage signal at both ends of the electromagnetic coil and both ends of the high-frequency current supply unit. In the case of a phase difference from the voltage signal, information on the phase difference between the AC component of the voltage signal at both ends of the electromagnetic coil and the voltage signal at both ends of the high-frequency current supply unit, and the known voltage at both ends of the electromagnetic coil Using the information indicating the relationship between the proximity distance and the phase difference between the AC component of the signal and the voltage signal at both ends of the high-frequency current supply unit, and determining the proximity distance having a known relationship with the pressing force. The sensor holding method according to claim 9, wherein there is a sensor holding method.

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