JP2994988B2 - Displacement measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a radiation environment in nuclear power, space, etc., or in a general industry, where workers are inaccessible due to a bad environment (temperature, pressure, atmosphere, etc.). It relates to displacement measurement technology.

[0002]

2. Description of the Related Art One of measuring instruments for measuring displacement remotely,
There is a differential transformer type displacement meter utilizing an electromagnetic action. Briefly explaining the principle of a displacement measuring device using a differential transformer and an example of a measuring system with reference to FIG. 1, an AC is applied to a primary coil of a differential transformer by an AC constant current power supply module for excitation, and two secondary coils are applied. The output is processed by the arithmetic processing module. A core whose displacement is to be measured is provided between the primary coil and the secondary coil, and the output of the secondary coil changes according to the displacement of the core. This is displayed on the displacement indicator. Such displacement meters require periodic calibration tests to ensure accuracy, which is conventionally done by an operator approaching a differential transformer, giving it a known forced displacement, and indicating The calibration test was performed by adjusting the electric circuit up to the meter.

[0003]

However, if the position where the differential transformer is placed is in a narrow space, in a bad environment such as a radiation environment, temperature, pressure, atmosphere, etc., it is difficult for an operator to access it. Cannot be given a forced displacement,
It is impossible to perform a calibration test. For example, when the differential transformer is used by being incorporated in a device under a radiation environment, calibration is performed by itself before being incorporated into the device, and calibration after the incorporation cannot be performed. For this reason, even in a place where a worker cannot access, it is expected that the displacement meter is calibrated remotely without accessing the sensor, thereby improving the reliability of the measurement data.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem.
It is an object of the present invention to provide a displacement measuring device that can add a forced displacement for a calibration test remotely to increase the reliability of measurement data.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a displacement measuring instrument using a differential transformer in which a core is attached to a displacement transmission rod penetrating a differential transformer, and a secondary output changes according to the displacement of the core. The displacement transmission rod comprises a first displacement transmission rod connected to a displacement measurement object side, and a second displacement transmission rod connected to a forced displacement addition mechanism and having the core attached thereto. A transmission rod slide mechanism that integrates the first and second displacement transmission rods, wherein the transmission rod slide mechanism is configured to move when the forcible displacement is applied from the forcible displacement applying mechanism. The first and second displacement transmitting rods can be freely slid with each other, and when the forcible displacement is not applied from the forcible displacement applying mechanism, the first and second displacement transmitting rods are moved one by one. Characterized in that so as to reduction. Further, according to the present invention, the forcible displacement applying mechanism applies a forcible displacement in the axial direction to the second displacement transmission rod by a remote command, and when the remote command is released, the second displacement transmission rod moves in the axial direction. It does not hinder. Also,
The present invention is characterized in that the transmission rod slide mechanism is configured to couple the first displacement transmission rod and the second displacement transmission rod with a predetermined spring force. Further, the present invention is characterized in that the transmission rod slide mechanism has a configuration in which an electromagnet is attached to one of the first and second displacement transmission rods and a ferromagnetic material is attached to the other. Further, the present invention is characterized in that a part of the displacement transmission system is provided with position detection means capable of remote detection.

[0006]

According to the present invention, the core of the differential transformer is positioned at a position corresponding to the displacement of the object to be measured when measuring the displacement, and the core is separated from the position corresponding to the displacement of the object to be measured during the calibration test, and the core is remotely operated. By freely moving the core by the specified stroke, even when an operator cannot access the core, the forced displacement for the calibration test can be remotely applied to the differential transformer.

[0007]

Embodiments of the present invention will be described below. First, a displacement meter used for a material irradiation test device in the fast experimental reactor "JOYO" will be described as an example. Fast experimental reactor Joyo
As one of the material irradiation test devices in the above, there is a test device for examining the tensile creep strength of a material under a radiation irradiation environment called an out-of-furnace material irradiation device. In the irradiation test using the out-of-pile material irradiation equipment, the test section containing the material test specimens was used to test by irradiating stronger radiation in the narrow space between the “Joyo” reactor vessel and the safety vessel. It is located at almost the same height as the core.

FIG. 2 shows the arrangement of the out-of-furnace material irradiation apparatus and the appearance of the out-of-furnace material irradiation apparatus. FIG. 2 also shows an enlarged view near the capsule portion. The out-of-pile material irradiating apparatus is disposed in the containment vessel, and is roughly divided into an out-of-pile material irradiating apparatus main body 1 and auxiliary equipment including a pressure operation panel 9 and a measurement control panel 10. In order to irradiate at the same height as the core in the narrow space between the furnace container 5 and the safety container 6, the external material irradiation apparatus main body accommodates three test sections in three capsules 2, respectively. Are connected by a flexible hose 3, which extends to the upper floor 4 of the reactor, which is accessible to the workers, that is, from the upper floor, three capsules are suspended by hoses. . In addition, in order to smoothly insert the out-of-pile material irradiation apparatus main body into the narrow space between the reactor vessel 5 and the safety vessel 6, a guide tube 8 into which the out-of-pile material irradiation apparatus main body can be inserted in advance is provided in the space. A hollow flexible hose to be called is laid through the guide pipe 7.

The accessory equipment includes a pressure control panel 9 and a measurement control panel 10. The pressure control panel 9 supplies gas for remotely applying a tensile force to the material test piece from the gas cylinder to the gas pipe 1.
1 is a facility for supplying and exhausting gas through the
Then, control of the gas pressure, heater control for keeping the temperature of the material test piece constant, measurement of the amount of elongation displacement of the material test piece and the temperature of each part are performed. Therefore, in the hose 3 of the out-of-furnace material irradiation apparatus main body, an electric wiring 12 including these gas pipes 11, the power lines of the electric heater, and the respective measurement lines passes.

Next, the internal structure and functions of the three capsules will be described with reference to FIG. The capsule 2 is a cylindrical outer shell having a rounded top and bottom. At the upper part of the capsule, a perforated disk 50 is fixed to the capsule. A transformer mounting cylinder 70 is connected to the perforated disk 50 by screws 52. A differential transformer 51 having a hole that does not pass through at the center is hermetically connected to the transformer mounting cylinder 70 at the lower end thereof, and is built into the transformer mounting cylinder 70. Inside the differential transformer 51, there is a coil 56, and its electric wiring 12 is drawn out to the upper side in the figure.
Further, the core 57 is provided in a hole which does not penetrate the differential transformer, and the structural connection will be described later. Differential transformer 51
A gas chamber cylinder 53 is connected to the lower part of the lower part so that the internal space is airtight. In addition, the gas pipe 11 penetrates through a part of the cylinder 70 for assembling the transformer and is connected to the cylinder for incorporation of the transformer so as to be airtight, and is drawn into the internal space of the gas chamber cylinder 53. A bellows lower member 54 having a hole in the center is connected to the lower portion of the gas chamber cylinder 53 so that the internal space of the gas chamber cylinder is airtight. A perforated guide member 55 is provided inside the bellows lower member 54.
Are integrated. A relay cylinder 58 having a perforated bottom plate is connected to a lower portion of the bellows lower member 54. At the center of the bottom plate of the relay cylinder 58, a yoke 59 having a screw formed on the upper portion is connected with a nut 60. A material test piece 61 is connected to a screw hole at a lower portion of the yoke 59 by screw connection. Further, a heat insulating material 62 and an electric heater 63 are connected to a lower portion of the bottom plate of the relay cylinder 58 so that the material test piece 61 can be maintained at a predetermined test temperature. Here, the description of the power line for the electric heater and the thermocouple thermometer used for controlling the electric heater will be omitted. The structure described so far is a structure that is integral with the capsule and does not move in the tensile creep strength test.

The following are the relatively moving parts of the test. The lower part of the material test piece 61 has a bulging shape, and the two are joined at the lower part of the transmission yoke 64 by a structure sandwiching the lower part. The transmission yoke 64 is connected to the relay cylinder 58.
The structure penetrates freely through the hole of the bottom plate, so that it does not interfere with the bottom plate of the relay cylinder. The disk 64a on the upper side of the transmission yoke 64 has a screw hole at the center, and is screwed to the rod 65a of the bellows upper member 65 located on the upper side thereof.
A nut 66 is connected. The rod 65a of the bellows upper member 65 does not interfere with the bellows lower member 54 and the guide member 55 because the rod 65a penetrates the opening of the bellows lower member 54 and the guide member 55. Between the bellows upper member 65 and the bellows lower member 54, a telescopic bellows 67 is incorporated in a space inside the gas chamber cylinder 53 in an airtight structure. There is a screw hole at the center of the bellows upper member 65, which is screw-connected to the transmission rod 68 located at the upper portion thereof, and the nut 69 is connected thereto. Here, a part of the transmission rod 68 is
The core is inserted into a hole at the center of the differential transformer 51.

With such a configuration, the following functions are performed during the tensile creep strength test. (1) When a gas pressure is applied to the gas pipe 11 to pressurize the inside of the gas chamber cylinder 53, the bellows upper member 65 is pushed downward, and the bellows upper member 65 passes through a transmission yoke 64 integrally formed with a rod 65a and a nut 66. Thus, a tensile force can be applied to the lower part of the material test piece 61. (2) When the material test piece 61 is extended by the applied tensile force, the displacement is transmitted to the transmission rod 68 via the transmission yoke 64, the rod 65a, and the bellows upper member 65, and the core 57 and the coil 56 in the transmission rod 68 are transmitted. Can cause a relative shift in the positional relationship between. By the same theory, even if the material test piece 61 breaks, the core 57 and the coil 56
Can cause a relative shift in the positional relationship between. (3) If a relative displacement occurs in the positional relationship between the core 57 and the coil 56, a change in an electric signal based on the measurement principle of the differential transformer occurs, and the displacement is obtained by electrically processing the change. Can be.

[0013] Since the displacement measurement is performed in such a form, there is an environment in which a calibration test that should be periodically performed cannot be performed by a measuring instrument. In other words, in general, a periodic calibration test that guarantees the accuracy of a displacement meter is performed by an operator directly adding a known amount of displacement to a differential transformer that is the sensor. In the case of (1), the position where the sensor is placed is a narrow space, the radiation environment, and the bad conditions of the inert gas atmosphere overlap, so that the operator cannot access the sensor and cannot carry out the operation.

An embodiment in which the differential transformer of the out-of-furnace material irradiation apparatus is remotely calibrated will be described with reference to FIG. In FIG. 4, the differential transformer 100 is basically the same as the differential transformer 51 of FIG. 3, and is different only in that a center hole is penetrated. A transmission rod passes through the through-hole, and this transmission rod has a double structure that can slide with at least the same axis in at least the differential transformer portion. A part of the transmission rod of the double-structured transmission rod connected to the forcible displacement applying device, which will be described later, is a core 102 that causes an electromagnetic induction action with the coil 101 of the differential transformer. One end of the differential transformer, that is, the side to which the measurement displacement is transmitted has an end of the transmission rod double structure, and has a transmission rod slide mechanism 103. Here, for convenience of explanation, each of the transmission rods having the double structure is referred to as a transmission rod A104 and a transmission rod B105. The transmission rod A104 is a member corresponding to the transmission rod 68 described in FIG. 3, and is displaced in accordance with the measurement displacement. The transmission rod B105 passes through the differential transformer 100 and is connected to a later-described forced displacement adding mechanism 106.

Next, the transmission rod slide mechanism 103 will be described. The transmission rod A104 has a collar A107 and a seat 1
08 is being worked on. A collar B109 is also machined at the end of the transmission rod B105. The collar A and the collar B are tension-coupled by a spring 110 so that the collar B 109 comes into contact with the seat 108 when no forcible displacement is applied from a forcible displacement applying mechanism described later. Here, the spring 110
Is strong enough to attract the transmission rod B when no forcible displacement is applied from the forcible displacement adding mechanism described below,
Further, a spring having such a spring characteristic that is weak enough to displace the transmission rod B (displaced upward in the drawing) when a forced displacement is applied is selected.

A transmission rod B is provided on the other side of the differential transformer.
There is a forced displacement adding mechanism 106 sharing the same 105. The forced displacement applying mechanism is a mechanism using the principle of a linear stepping motor, which is an existing technology. In the forcible displacement adding mechanism 106, a bearing 1 that slidably supports the transmission rod B105 at both ends while restricting the rotation of the rod.
There are eleven. The transmission rod B105 has a cylindrical permanent magnet 112 in the forcible displacement adding mechanism 106.
And the mover 113 are machined. Forced displacement addition mechanism 1
The inside of 06 is a cylindrical stator 114, on which a plurality of windings 115 are attached. In the forced displacement applying mechanism having such a configuration, when an electric signal is applied to the winding 115 from an external control signal transmitter (not shown), a moving magnetic field is generated in the stator, and the fixed magnetic field is fixed without rotating the transmission rod B. Due to the electromagnetic effect between the child and mover,
Can be moved axially. Here, the amount of axial movement of the transmission rod B can be any known amount by adjusting an external control signal transmitter. Also,
If the current supply to the windings is stopped, the electromagnetic action does not function. Therefore, the transmission rod B can freely move in the axial direction by an external force without rotating.

It should be noted that the description of the electric wiring associated with the differential transformer 100 and the linear stepping motor as the forced displacement adding device 106 will be omitted.

With such a configuration, since each part has the above-described characteristics, the following operations and effects can be obtained in this embodiment.

At the time of measuring the displacement, the forced displacement adding mechanism 106 is not operated. As a result, the action of the transmission rod slide mechanism 103, that is, the collar B109
The transmission rod A104 and the transmission rod B105 move integrally as a result of the transmission rod A104 being a member corresponding to the transmission rod 68 described with reference to FIG. The core 102 of the transmission rod B105 moves according to the displacement, and the same measurement effect as the displacement measurement in the case of FIG. 3 can be obtained.

When the calibration test of the differential transformer 100 is performed, the transmission rod slide is applied by operating the forced displacement adding mechanism 106, that is, from the external control signal transmitter to the winding 115 of the forced displacement adding mechanism. In the mechanism 103, the collar B109 applies an electric signal in a direction away from the seat. Then, the transmission rod B105 moves by a known stroke corresponding to the signal, and
2 will also move.

The movement of the core causes a change in the output of the differential transformer, and this change in output becomes calibration data for a known displacement. After that, the adjustment position of the displacement measurement system may be adjusted as needed. Thus, the calibration test of the differential transformer type displacement meter can be performed. When the calibration test is completed, by stopping the current supply to the winding of the forcible displacement applying mechanism, it is possible to return to the state at the time of the displacement measurement by the spring action of the transmission rod slide mechanism.

Thus, the calibration test of the differential transformer type displacement meter can be performed by remote control.

FIG. 5 is a diagram showing another embodiment of the present invention. In the present embodiment, the transmission rod slide mechanism 103 in the embodiment of FIG. 4 is a transmission rod slide mechanism 200 composed of an electromagnet and a ferromagnetic material. That is,
The transmission rod A104 is provided with a collar A202 made of a ferromagnetic material (for example, iron or the like), the transmission rod B105 is also provided with a collar 203 of a non-magnetic material, and the collar B203 is provided with an electromagnet 201.

In this way, when the displacement is measured, the electromagnet 201 is energized so that the
2 and the transmission rod A104 and the transmission rod B10.
5 can be integrated.

Further, when the calibration test of the differential transformer is performed, the suction of the collar A can be released by stopping the power supply to the electromagnet, so that the transmission rod A and the transmission rod B can slide freely.

Further, in the present invention, the forced displacement applying mechanism is also applied by mechanically working a piston structure operated by fluid pressure or a structure based on a principle that a swinging iron piece is attracted to an electromagnet. Can be.

Further, a position detector may be provided in a part of the displacement transmission system, and its output may be used as calibration data at the time of the displacement meter calibration test.

FIG. 6 shows an embodiment provided with a position detector.
A projection 15 is provided on a part of the transmission rod B105 as a displacement transmission system.
1 is provided. One or more limit switches 152, which are position detectors, are attached to a structure that is fixed with respect to the movement of the displacement transmission system. Here, when the protrusion 151 of the transmission rod B105 is displaced to a specific position, the limit switch contacts the finger 153 of the limit switch 152 and is mounted so that the limit switch emits an electric signal. By doing so, it is possible to know that the displacement of the transmission rod B105 has reached a specific displacement amount, and it is possible to obtain calibration data for a displacement meter calibration test.

In the above-described embodiment, the out-of-furnace material irradiation apparatus has been described as an example. However, the present invention is not limited to this. The present invention can be similarly applied to a displacement measuring instrument installed in an inferior environment such as a temperature, a pressure, and an atmosphere, such as a differential transformer used for detecting an open / close position.

[0030]

As described above, according to the present invention, the following excellent effects can be obtained as compared with the prior art. Since a forced displacement can be added to the differential transformer remotely, a periodic calibration test can also be performed on a displacement meter placed in an environment that is inaccessible to workers. Since the periodic calibration test can be performed, the reliability of the measured displacement data can be improved. Since a calibration test can be performed remotely by adding a forced displacement to the differential transformer, it is not necessary for an operator to go around and approach the differential transformer, so that the work efficiency of the calibration test can be increased. It is also possible to perform calibration while using.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a differential transformer.

FIG. 2 is a diagram showing an arrangement of an out-of-furnace material irradiation apparatus and its appearance.

FIG. 3 is a view showing a capsule configuration of the out-of-pile material irradiation apparatus.

FIG. 4 is a diagram showing one embodiment of the displacement measuring device of the present invention.

FIG. 5 is a diagram showing another embodiment of the present invention using an electromagnet.

FIG. 6 is a diagram showing another embodiment of the present invention using a position detector.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Out-of-reactor material irradiation apparatus main body, 2 ... Capsule, 3 ... Hose, 4 ... Reactor upper floor, 5 ... Reactor vessel, 6 ... Safety vessel, 7 ... Guide pipe, 8 ... Guide tube, 9 ... Pressure operation Panel, 10: Measurement control panel, 11: Gas pipe, 12: Wiring, 100: Differential transformer, 101: Coil, 102:
Core, 103: transmission rod slide mechanism, 104: transmission rod A, 105: transmission rod B, 106: forced displacement addition mechanism, 107: collar A, 108: seat, 109: collar B, 110: spring, 111: bearing, 112: permanent magnet, 113: mover, 114: stator, 115: winding,
200: transmission rod slide mechanism, 201: electromagnet, 2
02 ... collar A, 203 ... collar B, 151 ... protrusion, 152
... Limit switch, 153 ... Finger.

Continuation of the front page (72) Inventor Kazuoka Kataoka 4002 Narita-cho, Oarai-machi, Higashiibaraki-gun, Ibaraki Pref. Oarai Engineering Center (56) References JP-A-59-180419 (JP, A) (58) ) Surveyed field (Int.Cl. ⁶ , DB name) G01B 7/00-7/34

Claims (5)

(57) [Claims] 1. A displacement measuring device using a differential transformer in which a core is attached to a displacement transmission rod penetrating a differential transformer and a secondary output changes according to the displacement of the core, wherein the displacement transmission rod has a displacement a first displacement transmission rod connected to the measurement object side, is connected to the forced displacement applying mechanism consists of two double rod sliding structure consisting of the second displacement transmission rod wherein the core is attached, and further, Transmission integrating the first and second displacement transmission rods
A transmission rod slide mechanism comprising a rod slide mechanism;
Has a forcible displacement applied from the forcible displacement adding mechanism.
When the first and second displacement transmission rods slide freely
From the forcible displacement adding mechanism.
Is not applied, the first and second displacement transmission rods are
Displacement measuring device characterized by being integrated . 2. The displacement measuring device according to claim 1, wherein the forcible displacement applying mechanism applies a forcible displacement in the axial direction to the second displacement transmission rod by a remote command, and when the remote command is released, the second forcible displacement applying mechanism applies the second displacement transmission rod. A displacement measuring device, which does not hinder axial displacement of a displacement transmission rod. 3. The displacement measuring device according to claim 1, wherein the transmission rod slide mechanism is configured to couple the first displacement transmission rod and the second displacement transmission rod with a predetermined spring force. A displacement measuring device characterized by the above-mentioned. 4. The displacement measuring device according to claim 1, wherein the transmission rod slide mechanism has a structure in which an electromagnet is attached to one of the first and second displacement transmission rods and a ferromagnetic material is attached to the other. And a displacement measuring instrument. 5. The displacement measuring device according to claim 1, wherein a part of the displacement transmitting system is provided with a position detecting means capable of remote sensing.