CA1299862C - Method of measuring inner diameter and configuration of tube - Google Patents
Method of measuring inner diameter and configuration of tubeInfo
- Publication number
- CA1299862C CA1299862C CA000584753A CA584753A CA1299862C CA 1299862 C CA1299862 C CA 1299862C CA 000584753 A CA000584753 A CA 000584753A CA 584753 A CA584753 A CA 584753A CA 1299862 C CA1299862 C CA 1299862C
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- CA
- Canada
- Prior art keywords
- tube
- measuring
- configuration
- measured
- inner diameter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Abstract
ABSTRACT
A method of measuring an inner diameter and a configuration of an inner surface of a tube to be measured, comprising:
holding a rotating shaft of a measuring head by a rotary bearing unit movable in a lengthwise direction of said tube and positioned at the center thereof, said measuring head being provided with a radius measuring sensor attached thereto; and rotating said measuring head by rotating said rotating shaft with said rotatory bearing unit kept stationary at one position in the lengthwise direction of the tube to successively measure, at various rotational angles, radii of the tube and rotational angles at which the respective radii are measured, thereby determining an inner diameter of the tube and a configuration of an inner surface in a circumferential direction thereof.
A method of measuring an inner diameter and a configuration of an inner surface of a tube to be measured, comprising:
holding a rotating shaft of a measuring head by a rotary bearing unit movable in a lengthwise direction of said tube and positioned at the center thereof, said measuring head being provided with a radius measuring sensor attached thereto; and rotating said measuring head by rotating said rotating shaft with said rotatory bearing unit kept stationary at one position in the lengthwise direction of the tube to successively measure, at various rotational angles, radii of the tube and rotational angles at which the respective radii are measured, thereby determining an inner diameter of the tube and a configuration of an inner surface in a circumferential direction thereof.
Description
12~ 862 METHOD OF MEASURING INNER DIAMETER
AND CONFIGURATION OF TUBE
BACKGROUND OF THE INVENTION
The present invention relates to a method of measuring an inner diameter of a tube and a configuration of an inner surface in a circumferential direction of the tube in such a manner that measuring head is rotated while a rotating shaft of the measuring head is held at the center of the tube to be measured to successively measure radii of the tube and rotational angles at which the respective radii are measured.
The present invention is a effective method for measuring, for example, an inner diametex and a configuration of an inner surface of a pressure tube used in a pressure tube type nuclear reactor by remote control, although not limited thereto.
There are various technical fields in which an inner diameter of a tube and a configuration of an inner surface th circumferential direction of the tube are necessary to be measured. A typical example of them includes the measurement of a pressure tube used in a pressure tube type nuclear reactor in addition of the measurement of a tube used in a heat exchanger or the like. The typical example, ~2~862 i.e, the measurement of an inner diameter of the pressure tube and a configuration of an inner surface in a circumferential direction thereof used in the pressure tube type nuclear reactor will be described hereinbelow.
The pressure tube constructing a reactor core of the pressure tube type nuclear reactor is very important equipment. The pressure tube hzs a characteristic that its inner diameter changes little by little as the reactor is operated for a longer period of time because the pressure tube is subject to radiation of neutron and further coolant (water) flowing in the interior of the pressure tube is in the state of high temperature and pressure. Therefore, the inner diameter is measured to monitor the amount of creep under the radiation during the entire operating period of the reactor.
In general, the interior of the pressure tube is subject to a high level radiation and the pressure tube is a very long tube of about 1Om including extension tube portions connected to its opposite ends with the diameter of about 118mm. Therefore, when the inner diameter of such pressure tube is measured, a remote controlled measuring device has been inserted into the interior of the pressure tube. Usually, the measurement is carried out every two to four years at the time of shutdown of the reactor.
Conventionally, the measurement has been carried out in such a manner that a measuring head is inserted into the pressure tube and moved axially while it is rotated to 12~862 measure an inner diameter of the tube. The measuring head comprises a pair of radius measuring sensors (2 pieces) disposed at diametrically opposite positions, and a holding means of the sensors which is integral with the sensors.
The holding means has a three-point supporting mechanism which comprises two fixed guide balls disposed at an interval of 120 degrees and one movable guide ball urged radially and outwardly by a spring or the like. As the radius measuring sensor, a noncontacting type ultrasonic sensor, a contact type differential transformer or the like has been used.
~ ith such a measuring method, however, the measuring head follows a change in the inner diameter of the tube because the measuring head is supported by the three guide balls projecting from an outer circumference thereof.
Therefore, a position of the center of rotation of the measuring head changes moment by moment and further the position cannot be detected so that an exact configuration of an inner surface in a circumferential direction of the tube cannot be measured. In particular, when the configuration of the inner surface in the circumferential direction of the pressure tube is considerably deformed from a truly round state, there is a drawback that the configuration of the inner surface cannot be measured and that the inner diameter cannot be exactly measured.
Moreover, in the above-described prior art technology, since the measuring head is composed of the radius measuring ~2~86Z, sensors and the holding means which is integral with the sensors, there is also a drawback that a measuring error is increased because of the vibration caused in the measuring head due to irregularity of the inner surface of the measuring tube to be measured when the mesuring head rotates at a high speed. Therefore, a rotational speed of the measuring head is restricted below a prescribed value and thus there is a problem that a high speed measurement cannot be effected.
SUMMARY OF INVEI~TION
It is an object of the present invention to overcome the drawbacks of the prior art described above and to provide a method which is capable of measuring a configuration of an inner surface in a circumferential direction of a tube at the same time when the inner diameter of the tube is measured through remote control.
It is another object of the present invention to provide a method of measuring an inner diameter and a configuration of an inner surface in a circumferential direction of a tube with a high speed and a high accuracy.
According to the present invention, the above-described objects can be accomplished by a method of measuring an inner diameter and a configuration of an inner surface of a tube to be measured comprising the steps of holding a rotating shaft of a measuring head by a rotary bearing unit movable in a lengthwise direction of the tube and positioned at the center thereof, the measuring head being provided with a radius measuring sensor attached thereto; and rotating the measuring head by rotating the rotating shaft with the rotary bearing unit kept stationary at one position in the lengthwise direction of the tube to successively measure, at various rotational angles, radii of the tube and rotational angles at which the respective radii are measured, thereby determining an inner diameter of the tube and a configuration of an inner surface in a circumferential direction thereof.
The measuring head may be provided with only one radius measuring sensor. Preferably, a noncontacting type sensor capable of detecting with a high speed operation, such as an ultrasonic sensor may be employed as the radius measuring sensor.
According to the method of the present invention, during the measurement of a configuration of an inner surface in a circumferential direction of the tube, a central shaft of the measuring head is held at the center of the tube to be measured by the rotary bearing unit and the central shaft does not vibrate in a radial direction, since the rotary beaing unit is kept stationary at one position in the lengthwise direction of the tube. In addition, since the radius of the tube and the rotational angle of the measuring head are measured simultaneously, the inner diameter of the tube and the configuration of the inner surface in a circumferential direction thereof can be measured accurately by taking a lot of measuring data on one measuring surface and plotting the values obtained from the data on a two-dimensional plane.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a schematic, explanatory wiew of an embodiment of a method of the present invention adapted for use in the measurement of a pressure tube of a pressure tube type nuclear reactor;
Fig. 2 is an enlarged fragmentary elevation partly in section which illustrates an embodiment of an apparatus empl~yed in a method of the pres~nt invention; and Fig. 3 is an explanatory view showing a measuring condition according to the method of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Figs. 1 and 2 illustrate an embodiment in which the present invention is applied to measure an inner diameter of a pressure tube of a pressure tube type nuclear reactor and a configuration of an inner surface in a circumferential direction thereof.
As shown in Fig. 1, an inner diameter and configuration measuring device 12 is inserted into the interior of a pressure tube 10 by remote control, sealed by a sealing member 14 and fixed by a sealing plug 16 in order to measure an inner diameter and a configuration of an inner surface in a circumferential direction of the pressure tube 10. The inner diameter and configuration measuring device 12 can easily be inserted and fixed by using a refueling machine in the case of a power plant employing the advanced thermal reactor "Fugen" developed by Doryokuro Kakunenryo Kaihatsu Jigyodan (Power Reactor and Nuclear Fuel Development Corporation) in Japan. The inner diameter and configuration measuring device 12 is connected to a control unit 20 through a cable 18 and the measurement is carried out by remote control from the control unit 20.
The inner diameter and configuration measuring device 12 is substantially arranged as described hereinbelow. The device 12 includes a main body portion 24 provided with a vertically moving mechanism 22 to enable the measurement at any arbitrary positions in the lengthwise direction of the pressure tube 10. A holding mechanism 26, which is provided with three guide balls disposed at the interval of an angle of 120and projected from the outer circumference of the main body portion 24, is projectingly disposed in the vicinity of the upper end of the main body portion 24. The respective guide balls have their tip ends brought into abutment against the inner wall of the pressure tube 10 to enable that the main body portion 24 moves upwardly and downwardly in the lengthwise direction of the pressure tube while it is guided at the center of the pressure tube. The holding mechanism may be a three-point supporting mechanism composed of a combination of two fixed guide balls and one movable guide ball urged radially and outwardly by a spring or the like similarly to e prior art.
A rotary bearing unit 28 is assembled at the center of the upper section of the main body portion 24. A rotating shaft 30 is rotatably and engagingly held by the rotary bearing unit 28 and a measuring head 32 is held by the rotating shaft 30 at the upper end section of the main body portion 24. Further, a rotational driving mechanism (not shown) is assembled in the upper end section of the main body portion 24 for rotating the rotating shaft 30. A
radius measuring sensor 34 (for example, an ultrasonic sensor) is attached to the measuring head 32 and a rotational angle sensor 36 is attached to the rotating shaft 30.
Incidentally, it is indispensable that electronic components, polymer materials and the like to be assembled in the interior of the measuring sensor 34 and in the inner diameter and configuration measuring device 12 be resistant to radiation to carry out the present invention, because the inner diameter and configuration measuring device 12 is used in a circumstance of a high level radiation.
The inner diameter and the configuration of the inner surface of the pressure tube is measured as described hereinbelow. First, the measuring head 32 is moved by using the vertically moving mechanism 22 to a height where the measurement is required and is stopped there. Next, the measuring head 32 is rotated by using the rotational driving mechanism in the condition in which the operation of the vertically moving mechanism 22 is stopped. During the rotation of the measuring head 32, radii ro, r1,..., rn of the pressure tube are measured successively by the radius measuring sensor 34 and rotational angles eO, e1, ..., en of the measuring head 32 at which the respective radii are measured successively by the rotational angle sensor 36, as shown in Fig. 3. An interval of the measurements in the circumferential direction is expanded when a rough configuration is to be determined or the interval is narrowed when a detailed configuration is to be etermined depending on a purpose of the measurement.
When the measurement at one position in the lengthwise direction of the pressure tube 10 has heen completed, the measurement is interrupted temporarily and the measuring head 32 is moved during the interruption to another height where the measurement is required, as shown in an arrow A in Fig. 2. Then, the movement is stopped and the measuring head 32 is rotated again as shown by an arrow B to repeat the measurement likewise.
g _ 12C~862 The reason why the vertical movement of the measuring head 32 is interrupted during the measurement is that the accuracy in measuring is improved. More specifically, if the measuring head 32 is moved upwardly and downwardly during the measurement, the holding mechanism 26 also moves together with it and the holding mechanism 26 moves following a configuration of the inner surface of the pressure tube 10 w-th a result that the rotating shaft 30 of the measuring head 32 moves laterally. Such a lateral movement, which is added to a measured value as an error, is avoided by the method of the prsent invention.
After the radii (rO, rl, ..., rn) and the angles (eo, el,..., en) have been measured, the value (rO, eO),(rl, el), ...,(rn, en) as pairs are plotted on a two-dimentional plane to determine the inner diameter of the pressure tube 10 and the configuration of the inner surface in the circumferential direction thereof. When there is a large amount of measuring data, they may be processed by using a computer or the like and when there is a small amount of measuring data, they may be processed manually.
In the measuring method of the present invention, the accuracy of the radius measuring sensor 34, the accuracy of the rotational angle sensor 36 and the vibration of the measuring head 32 directly affect the accuracy in measuring.
Therefore, it is important to keep the accuracies of these sensors within predetermined allowable values depending on the required accuracy in measuring.
12C~3862 As ls apparent in the foregoing, according to the method of the present invention, the rotary bearing unit is held to prevent the rotating shaft of the measuring head from vibrating at the center if a tube to be measured and, in such a condition, the measuring head is rotated to successively measure radii of the tube and rotational angles at which the respective radii are measured. As a result, the position where the inner diameter is measured can exactly be detected so that an exact configuration of an inner surface in a circumferential direction of the tube, which cannot be measured by a conventional technology, can be measured. Thus, enen if the tube to be measured is greatly deformed from a true roudness, an inner diameter of the tube can be accurately measured.
Further according to the method of the present invention, the necessary number of measuring data of radii of a tube and rotational angles can be obtained with respect to one inner surface in a circumferential direction of the tube. Therefore, an amount of creep of a pressure tube under radiation can be measured more accurately by the method of the present invention than by the conventional method. Thus, data for improving safety and performance of a nuclear reactor and for expecting the surviving life thereof can be abundantly obtained.
In addition, according to the present invention, since the rotary bearing unit is kept stationary when a configuration of an inner surface in a circumferential 12C~ 62 direction of a tube is measured, the measuring head does not vibrate. Therefore, it becomes possible to carry out a high speed measurement accurately particulary when a sensor such as an ultrasonic sensor capable of effecting the measurement at a high speed is used, which makes the measuring speed by several tens of times higher than that obtained in the conventional method. As a result, a time required for a routine inspection can be shortened and an availability factor of a nuclear reactor can be improved.
AND CONFIGURATION OF TUBE
BACKGROUND OF THE INVENTION
The present invention relates to a method of measuring an inner diameter of a tube and a configuration of an inner surface in a circumferential direction of the tube in such a manner that measuring head is rotated while a rotating shaft of the measuring head is held at the center of the tube to be measured to successively measure radii of the tube and rotational angles at which the respective radii are measured.
The present invention is a effective method for measuring, for example, an inner diametex and a configuration of an inner surface of a pressure tube used in a pressure tube type nuclear reactor by remote control, although not limited thereto.
There are various technical fields in which an inner diameter of a tube and a configuration of an inner surface th circumferential direction of the tube are necessary to be measured. A typical example of them includes the measurement of a pressure tube used in a pressure tube type nuclear reactor in addition of the measurement of a tube used in a heat exchanger or the like. The typical example, ~2~862 i.e, the measurement of an inner diameter of the pressure tube and a configuration of an inner surface in a circumferential direction thereof used in the pressure tube type nuclear reactor will be described hereinbelow.
The pressure tube constructing a reactor core of the pressure tube type nuclear reactor is very important equipment. The pressure tube hzs a characteristic that its inner diameter changes little by little as the reactor is operated for a longer period of time because the pressure tube is subject to radiation of neutron and further coolant (water) flowing in the interior of the pressure tube is in the state of high temperature and pressure. Therefore, the inner diameter is measured to monitor the amount of creep under the radiation during the entire operating period of the reactor.
In general, the interior of the pressure tube is subject to a high level radiation and the pressure tube is a very long tube of about 1Om including extension tube portions connected to its opposite ends with the diameter of about 118mm. Therefore, when the inner diameter of such pressure tube is measured, a remote controlled measuring device has been inserted into the interior of the pressure tube. Usually, the measurement is carried out every two to four years at the time of shutdown of the reactor.
Conventionally, the measurement has been carried out in such a manner that a measuring head is inserted into the pressure tube and moved axially while it is rotated to 12~862 measure an inner diameter of the tube. The measuring head comprises a pair of radius measuring sensors (2 pieces) disposed at diametrically opposite positions, and a holding means of the sensors which is integral with the sensors.
The holding means has a three-point supporting mechanism which comprises two fixed guide balls disposed at an interval of 120 degrees and one movable guide ball urged radially and outwardly by a spring or the like. As the radius measuring sensor, a noncontacting type ultrasonic sensor, a contact type differential transformer or the like has been used.
~ ith such a measuring method, however, the measuring head follows a change in the inner diameter of the tube because the measuring head is supported by the three guide balls projecting from an outer circumference thereof.
Therefore, a position of the center of rotation of the measuring head changes moment by moment and further the position cannot be detected so that an exact configuration of an inner surface in a circumferential direction of the tube cannot be measured. In particular, when the configuration of the inner surface in the circumferential direction of the pressure tube is considerably deformed from a truly round state, there is a drawback that the configuration of the inner surface cannot be measured and that the inner diameter cannot be exactly measured.
Moreover, in the above-described prior art technology, since the measuring head is composed of the radius measuring ~2~86Z, sensors and the holding means which is integral with the sensors, there is also a drawback that a measuring error is increased because of the vibration caused in the measuring head due to irregularity of the inner surface of the measuring tube to be measured when the mesuring head rotates at a high speed. Therefore, a rotational speed of the measuring head is restricted below a prescribed value and thus there is a problem that a high speed measurement cannot be effected.
SUMMARY OF INVEI~TION
It is an object of the present invention to overcome the drawbacks of the prior art described above and to provide a method which is capable of measuring a configuration of an inner surface in a circumferential direction of a tube at the same time when the inner diameter of the tube is measured through remote control.
It is another object of the present invention to provide a method of measuring an inner diameter and a configuration of an inner surface in a circumferential direction of a tube with a high speed and a high accuracy.
According to the present invention, the above-described objects can be accomplished by a method of measuring an inner diameter and a configuration of an inner surface of a tube to be measured comprising the steps of holding a rotating shaft of a measuring head by a rotary bearing unit movable in a lengthwise direction of the tube and positioned at the center thereof, the measuring head being provided with a radius measuring sensor attached thereto; and rotating the measuring head by rotating the rotating shaft with the rotary bearing unit kept stationary at one position in the lengthwise direction of the tube to successively measure, at various rotational angles, radii of the tube and rotational angles at which the respective radii are measured, thereby determining an inner diameter of the tube and a configuration of an inner surface in a circumferential direction thereof.
The measuring head may be provided with only one radius measuring sensor. Preferably, a noncontacting type sensor capable of detecting with a high speed operation, such as an ultrasonic sensor may be employed as the radius measuring sensor.
According to the method of the present invention, during the measurement of a configuration of an inner surface in a circumferential direction of the tube, a central shaft of the measuring head is held at the center of the tube to be measured by the rotary bearing unit and the central shaft does not vibrate in a radial direction, since the rotary beaing unit is kept stationary at one position in the lengthwise direction of the tube. In addition, since the radius of the tube and the rotational angle of the measuring head are measured simultaneously, the inner diameter of the tube and the configuration of the inner surface in a circumferential direction thereof can be measured accurately by taking a lot of measuring data on one measuring surface and plotting the values obtained from the data on a two-dimensional plane.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a schematic, explanatory wiew of an embodiment of a method of the present invention adapted for use in the measurement of a pressure tube of a pressure tube type nuclear reactor;
Fig. 2 is an enlarged fragmentary elevation partly in section which illustrates an embodiment of an apparatus empl~yed in a method of the pres~nt invention; and Fig. 3 is an explanatory view showing a measuring condition according to the method of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Figs. 1 and 2 illustrate an embodiment in which the present invention is applied to measure an inner diameter of a pressure tube of a pressure tube type nuclear reactor and a configuration of an inner surface in a circumferential direction thereof.
As shown in Fig. 1, an inner diameter and configuration measuring device 12 is inserted into the interior of a pressure tube 10 by remote control, sealed by a sealing member 14 and fixed by a sealing plug 16 in order to measure an inner diameter and a configuration of an inner surface in a circumferential direction of the pressure tube 10. The inner diameter and configuration measuring device 12 can easily be inserted and fixed by using a refueling machine in the case of a power plant employing the advanced thermal reactor "Fugen" developed by Doryokuro Kakunenryo Kaihatsu Jigyodan (Power Reactor and Nuclear Fuel Development Corporation) in Japan. The inner diameter and configuration measuring device 12 is connected to a control unit 20 through a cable 18 and the measurement is carried out by remote control from the control unit 20.
The inner diameter and configuration measuring device 12 is substantially arranged as described hereinbelow. The device 12 includes a main body portion 24 provided with a vertically moving mechanism 22 to enable the measurement at any arbitrary positions in the lengthwise direction of the pressure tube 10. A holding mechanism 26, which is provided with three guide balls disposed at the interval of an angle of 120and projected from the outer circumference of the main body portion 24, is projectingly disposed in the vicinity of the upper end of the main body portion 24. The respective guide balls have their tip ends brought into abutment against the inner wall of the pressure tube 10 to enable that the main body portion 24 moves upwardly and downwardly in the lengthwise direction of the pressure tube while it is guided at the center of the pressure tube. The holding mechanism may be a three-point supporting mechanism composed of a combination of two fixed guide balls and one movable guide ball urged radially and outwardly by a spring or the like similarly to e prior art.
A rotary bearing unit 28 is assembled at the center of the upper section of the main body portion 24. A rotating shaft 30 is rotatably and engagingly held by the rotary bearing unit 28 and a measuring head 32 is held by the rotating shaft 30 at the upper end section of the main body portion 24. Further, a rotational driving mechanism (not shown) is assembled in the upper end section of the main body portion 24 for rotating the rotating shaft 30. A
radius measuring sensor 34 (for example, an ultrasonic sensor) is attached to the measuring head 32 and a rotational angle sensor 36 is attached to the rotating shaft 30.
Incidentally, it is indispensable that electronic components, polymer materials and the like to be assembled in the interior of the measuring sensor 34 and in the inner diameter and configuration measuring device 12 be resistant to radiation to carry out the present invention, because the inner diameter and configuration measuring device 12 is used in a circumstance of a high level radiation.
The inner diameter and the configuration of the inner surface of the pressure tube is measured as described hereinbelow. First, the measuring head 32 is moved by using the vertically moving mechanism 22 to a height where the measurement is required and is stopped there. Next, the measuring head 32 is rotated by using the rotational driving mechanism in the condition in which the operation of the vertically moving mechanism 22 is stopped. During the rotation of the measuring head 32, radii ro, r1,..., rn of the pressure tube are measured successively by the radius measuring sensor 34 and rotational angles eO, e1, ..., en of the measuring head 32 at which the respective radii are measured successively by the rotational angle sensor 36, as shown in Fig. 3. An interval of the measurements in the circumferential direction is expanded when a rough configuration is to be determined or the interval is narrowed when a detailed configuration is to be etermined depending on a purpose of the measurement.
When the measurement at one position in the lengthwise direction of the pressure tube 10 has heen completed, the measurement is interrupted temporarily and the measuring head 32 is moved during the interruption to another height where the measurement is required, as shown in an arrow A in Fig. 2. Then, the movement is stopped and the measuring head 32 is rotated again as shown by an arrow B to repeat the measurement likewise.
g _ 12C~862 The reason why the vertical movement of the measuring head 32 is interrupted during the measurement is that the accuracy in measuring is improved. More specifically, if the measuring head 32 is moved upwardly and downwardly during the measurement, the holding mechanism 26 also moves together with it and the holding mechanism 26 moves following a configuration of the inner surface of the pressure tube 10 w-th a result that the rotating shaft 30 of the measuring head 32 moves laterally. Such a lateral movement, which is added to a measured value as an error, is avoided by the method of the prsent invention.
After the radii (rO, rl, ..., rn) and the angles (eo, el,..., en) have been measured, the value (rO, eO),(rl, el), ...,(rn, en) as pairs are plotted on a two-dimentional plane to determine the inner diameter of the pressure tube 10 and the configuration of the inner surface in the circumferential direction thereof. When there is a large amount of measuring data, they may be processed by using a computer or the like and when there is a small amount of measuring data, they may be processed manually.
In the measuring method of the present invention, the accuracy of the radius measuring sensor 34, the accuracy of the rotational angle sensor 36 and the vibration of the measuring head 32 directly affect the accuracy in measuring.
Therefore, it is important to keep the accuracies of these sensors within predetermined allowable values depending on the required accuracy in measuring.
12C~3862 As ls apparent in the foregoing, according to the method of the present invention, the rotary bearing unit is held to prevent the rotating shaft of the measuring head from vibrating at the center if a tube to be measured and, in such a condition, the measuring head is rotated to successively measure radii of the tube and rotational angles at which the respective radii are measured. As a result, the position where the inner diameter is measured can exactly be detected so that an exact configuration of an inner surface in a circumferential direction of the tube, which cannot be measured by a conventional technology, can be measured. Thus, enen if the tube to be measured is greatly deformed from a true roudness, an inner diameter of the tube can be accurately measured.
Further according to the method of the present invention, the necessary number of measuring data of radii of a tube and rotational angles can be obtained with respect to one inner surface in a circumferential direction of the tube. Therefore, an amount of creep of a pressure tube under radiation can be measured more accurately by the method of the present invention than by the conventional method. Thus, data for improving safety and performance of a nuclear reactor and for expecting the surviving life thereof can be abundantly obtained.
In addition, according to the present invention, since the rotary bearing unit is kept stationary when a configuration of an inner surface in a circumferential 12C~ 62 direction of a tube is measured, the measuring head does not vibrate. Therefore, it becomes possible to carry out a high speed measurement accurately particulary when a sensor such as an ultrasonic sensor capable of effecting the measurement at a high speed is used, which makes the measuring speed by several tens of times higher than that obtained in the conventional method. As a result, a time required for a routine inspection can be shortened and an availability factor of a nuclear reactor can be improved.
Claims (4)
1. A method of measuring an inner diameter and a configuration of an inner surface of a tube to be measured, comprising:
holding a rotating shaft of a measuring head by a rotary bearing unit movable in a lengthwise direction of said tube and positioned at the center thereof, said measuring head being provided with a radius measuring sensor attached thereto; and rotating said measuring head by rotating said rotating shaft with said rotatory bearing unit kept stationary at one position in the lengthwise direction of the tube to successively measure, at various rotational angles, radii of the tube and rotational angles at which the respective radii are measured, thereby determining an inner diameter of the tube and a configuration of an inner surface in a circumferential direction thereof.
holding a rotating shaft of a measuring head by a rotary bearing unit movable in a lengthwise direction of said tube and positioned at the center thereof, said measuring head being provided with a radius measuring sensor attached thereto; and rotating said measuring head by rotating said rotating shaft with said rotatory bearing unit kept stationary at one position in the lengthwise direction of the tube to successively measure, at various rotational angles, radii of the tube and rotational angles at which the respective radii are measured, thereby determining an inner diameter of the tube and a configuration of an inner surface in a circumferential direction thereof.
2. The method according to claim 1, which includes plotting the measured values of the radii and the rotational angles on a two-dimensional plane to determine the inner surface of the tube and the configuration of the inner surface in the circumferential direction thereof.
3. The method according to claim 1, wherein said rotary bearing unit is held within the tube by a three-point supporting mechanism to enable said unit to move upwardly and downwardly in the lengthwise direction of the tube while it is guided at the center of the tube.
4. The method according to claim 1, wherein said tube to be measured is a pressure tube of a pressure tube type nuclear reactor.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62-306562 | 1987-12-03 | ||
| JP30656287A JPH01147313A (en) | 1987-12-03 | 1987-12-03 | Method for measuring internal diameter and shape of tube |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1299862C true CA1299862C (en) | 1992-05-05 |
Family
ID=17958547
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000584753A Expired - Lifetime CA1299862C (en) | 1987-12-03 | 1988-12-01 | Method of measuring inner diameter and configuration of tube |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPH01147313A (en) |
| CA (1) | CA1299862C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN119413112A (en) * | 2025-01-03 | 2025-02-11 | 天津市天锻压力机有限公司 | A method and device for automatic measurement and correction of large cylindrical structural parts |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0436408U (en) * | 1990-07-24 | 1992-03-26 | ||
| JP2008026276A (en) * | 2006-07-25 | 2008-02-07 | Nanya Seisakusho:Kk | Coordinate detector for measuring position degree, and position degree measuring system |
| CN103604405B (en) * | 2013-08-28 | 2016-02-17 | 陕西福音假肢有限责任公司 | A kind of inner diameter measuring device of prosthetic socket |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5237464A (en) * | 1975-09-20 | 1977-03-23 | Nippon Kokan Kk <Nkk> | Method of measuring bore distribution of pipe |
| DE3024331C2 (en) * | 1980-06-27 | 1982-10-21 | Ludwig Dr.-Ing. 7500 Karlsruhe Pietzsch | Measuring device for the cylinder warpage in cylinder chambers |
-
1987
- 1987-12-03 JP JP30656287A patent/JPH01147313A/en active Pending
-
1988
- 1988-12-01 CA CA000584753A patent/CA1299862C/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN119413112A (en) * | 2025-01-03 | 2025-02-11 | 天津市天锻压力机有限公司 | A method and device for automatic measurement and correction of large cylindrical structural parts |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01147313A (en) | 1989-06-09 |
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