JP2012073174A - Tube wall thickness measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tube wall thickness measuring apparatus capable of accurately and simply measuring a wall thickness even of a damaged part such as a flaw and a dent is formed on the surface of an inspection object.SOLUTION: This tube wall thickness measuring apparatus for measuring a wall thickness of a tube 50 by an ultrasonic flaw detection includes: a locally submerged type ultrasonic probe 10; a cylindrical body 21 which forms in the inside, a medium space to be filled with contact medium; an opening 22 provided at one end side of the cylindrical body and formed at a curvature corresponding to the outer surface of the tube; a tool main body 2 provided at the other end side of the cylindrical body and having a retaining part for retaining the ultrasonic probe 10 and a cover part 23 for sealing the medium space; a seal member 3 interposed between the end edge of the opening 22 and the outer surface of the tube 50; medium injection means 4 injecting the contact medium in the medium space; and fixing means for pressing and fixing the tool main body 2 towards the outer surface of the tube 50. This tube wall thickness measuring apparatus is configured to measure the wall thickness of the tube by the ultrasonic probe 10, with the tool main body 2 fixed to the outer surface of the tube 50 via the seal member 3 by the fixing means.

Description

  The present invention relates to a tube thickness measuring apparatus that measures the thickness of a tube from the outer surface of the tube using a local water immersion ultrasonic probe, and in particular, local tube meat of a damaged part such as a scratch or a dent. The present invention relates to a tube wall thickness measuring device that is preferably used when measuring thickness.

  In general, ultrasonic flaw detection is often used for measuring the thickness of an object to be inspected as one of non-destructive inspection methods. For example, in the boiler 100 shown in FIG. 11, when a clinker attached to the wall surface of the furnace 101 falls on the bottom slope 102, a damaged portion 51 such as a scratch or a dent is partially formed in the bottom heat transfer tube 50 as shown in FIG. May occur. If the damaged portion 51 causes the heat transfer tube 50 to become partially thicker than the pressure vessel, it is necessary to repair or replace the heat transfer tube 50. Therefore, conventionally, as shown in FIG. 13, the thickness D of the heat transfer tube 50 is measured by ultrasonic flaw detection, and the depth d of the damaged portion 51 is subtracted from the thickness D of the heat transfer tube 50. The thickness was estimated to determine whether repairs were possible. However, since the high-temperature strength of the heat transfer tube 50 is reduced during boiler operation, a dent 52 is formed inside the damaged portion 51 where the clinker has fallen, and the tube thickness is actually kept above the specified level simply by deformation of the heat transfer tube 50. I may be leaning. In this case, there is a problem that unnecessary labor and repair costs are required for the repair work of the heat transfer tube 50.

  On the other hand, as an effective ultrasonic flaw detection method for detecting the thickness of an object to be inspected, as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2001-349880) and the like, a local water immersion method has been widely used conventionally. Yes. In the local water immersion method, a cylinder filled with a contact medium is interposed between the object to be inspected and the ultrasonic probe, and a film is stretched on the contact surface between the cylinder and the object to be inspected to hold the contact medium. It is the composition to do. Then, ultrasonic waves are incident on the object to be inspected through the contact medium from the ultrasonic probe, and the thickness is measured based on the reflected wave reflected by the end face of the object to be inspected.

  Patent Document 2 (Japanese Patent Laid-Open No. 2002-131297) discloses an ultrasonic inspection apparatus suitable for local thickness measurement of a scratched part, a spot welded part, or the like. This apparatus has a configuration in which a contact medium is filled in the unevenness of the object to be inspected, and further, a delay material having a height equal to or higher than the unevenness is disposed between the uneven portion and the ultrasonic probe to perform ultrasonic testing. It has become. Examples of the delay material include metals, non-metals, resins, and the like, and the delay material can stably scan the ultrasonic probe.

JP 2001-349880 A JP 2002-131297 A

  However, the local water immersion method described in Patent Document 1 is often applied mainly to large structures such as steel frames and bridges, and for example, thickness measurement of relatively small objects to be inspected such as heat transfer tubes, etc. When a damaged part such as a small scratch or dent is present on the surface of the object to be inspected, there is a problem that it is difficult for the contact medium to enter the damaged part through the film, and a minute space is formed and the flaw cannot be detected accurately. was there. In addition, since a film is interposed between the ultrasound probe and the object to be inspected, it may be difficult to analyze the reflected wave due to the reflected wave from the film surface or multiple reflected waves within the film. .

  In addition, the apparatus disclosed in Patent Document 2 also receives reflected waves from the end face and the inside of the delay material by the ultrasonic probe, making it difficult to analyze the reflected waves as in the case where a film is interposed. There was a thing. Further, since the contact medium is only filled between the delay material and the ultrasonic probe and the structure for holding it is not disclosed, it is possible to measure a flat test object from above. For example, it cannot be applied when the surface of the object to be inspected is a curved surface, such as a heat transfer tube, or when measuring the thickness in the horizontal direction.

  Therefore, in view of the problems of the prior art, the present invention is capable of accurately and easily measuring the wall thickness even when there is a damaged part such as a scratch or a dent on the surface of the object to be inspected. It aims at providing a measuring device.

  In order to solve the above-described problems, the present invention provides a pipe wall thickness measurement apparatus that performs pipe wall thickness measurement by ultrasonic flaw detection, a local water immersion type ultrasonic probe, and a medium space filled with a contact medium. A cylindrical body, an opening provided on one end side of the cylindrical body and having a curvature corresponding to the outer surface of the tube, and provided on the other end side of the cylindrical body to hold the ultrasonic probe A jig body having a holding part and a lid part for sealing the medium space, a seal member interposed between an edge of the opening and the outer surface of the tube, and the contact medium in the medium space And a fixing means for fixing the jig main body to the outer surface of the pipe, and the jig main body is fixed to the outer surface of the pipe via the seal member by the fixing means. The thickness of the tube is measured by the ultrasonic probe in a state.

  According to the present invention, the contact medium filled in the medium space of the cylindrical body is configured to directly contact the outer surface of the pipe from the opening of the cylindrical body, so that there are damaged parts such as scratches and dents on the outer surface of the pipe. Even in this case, the contact medium enters the irregularities of the damaged portion, and ultrasonic flaw detection can be performed with high accuracy. Moreover, since only the contact medium is interposed between the ultrasonic probe and the tube, the reflected wave required for the thickness measurement can be easily detected, and the thickness measurement can be performed accurately and easily. . Further, since the tube thickness is directly measured by the ultrasonic probe, measurement errors can be reduced, and whether or not the tube needs to be repaired can be easily determined from the measurement results. Furthermore, since the opening of the cylindrical body is formed with a curvature corresponding to the outer surface of the tube and a sealing member is interposed between the edge of the opening and the outer surface of the tube, the medium space is filled. It is possible to prevent the contact medium from leaking from the opening.

Further, the fixing means is a string base in which magnetic powder is mixed into the seal member to give a magnetic force, and the jig main body is fixed to the tube formed of a magnetic body by an adsorption force of the string base; It is preferable to do.
In this way, the string base is attached to the edge of the opening of the cylindrical body, and the seal member and the fixing means are integrated by providing the string base with functions of preventing leakage of the contact medium and fixing the jig body. Therefore, the apparatus configuration can be simplified and downsized.

Further, it is preferable that the fixing means is a magnet base attached to the outer peripheral surface of the cylindrical body, and the jig main body is fixed to the tube formed of a magnetic body by an attractive force of the magnet base. .
In this way, by attaching the magnet base to the outer peripheral surface of the cylindrical body and fixing the jig body to the outer surface of the pipe with this magnet base, the jig body can be more strongly fixed to the outer surface of the pipe. it can.
Further, as described above, the jig body can be easily attached and detached by adopting a configuration in which the jig body is attracted to the outer surface of the tube by a magnetic force using a string base or a magnet base.

Moreover, it is preferable that the holding unit includes a guide plate that supports the periphery of the ultrasonic transmission / reception surface of the ultrasonic probe and maintains a constant distance from the opening to the ultrasonic transmission / reception surface.
By providing the guide plate in this way, the ultrasonic probe can be positioned so as to keep the distance from the tube outer surface to the ultrasonic wave transmitting / receiving surface constant only by fixing the jig body to the tube outer surface, The wall thickness can be easily detected even when different parts of the tube are measured.

Further, the medium space is partitioned into two spaces communicating with each other with a minute gap by the guide plate, and the contact medium is injected from the medium injection means into the first medium space formed on the opening side. It is preferable that the air hole is provided in the second medium space formed on the lid side.
In this way, the first medium space and the second medium space are partitioned by the guide plate, and the contact medium is filled in the first medium space without any gap, so that the space between the ultrasonic probe and the outer surface of the tube is reduced. Water immersion can be ensured. Furthermore, by forming the second medium space, it is possible to prevent a large amount of contact medium leaking from the first medium space from flowing out of the apparatus.

Furthermore, it is preferable that the holding part has a mechanism for sliding the ultrasonic probe in a state where the distance from the outer surface of the tube is kept constant.
As described above, since the ultrasonic probe has a mechanism that slides in the axial direction of the tube, for example, the flaw detection range can be expanded within the range in which the cylindrical body comes into contact.

As described above, according to the present invention, the jig main body holds the contact medium in a state of being in direct contact with the outer surface of the tube, so that ultrasonic flaw detection can be performed with high accuracy.
In addition, since the opening of the cylindrical body is formed with a curvature corresponding to the outer surface of the tube, and a seal member is interposed between the edge of the opening and the outer surface of the tube, the contact filled in the medium space It is possible to prevent the medium from leaking from the opening.
Further, since the tube thickness is directly measured by the ultrasonic probe, measurement errors can be reduced, and whether or not the tube needs to be repaired can be easily determined from the measurement results.
Furthermore, the tube thickness measuring apparatus according to the present invention is applicable not only when the flaw detection surface is positioned in the vertical direction but also in the flaw detection surface in the horizontal direction.

It is a perspective view which shows the measurement state of the tube thickness measuring apparatus which concerns on embodiment of this invention. It is a sectional side view which shows the tube thickness measuring apparatus which concerns on 1st Embodiment of this invention. (A) is the sectional view on the AA line of the tube thickness measuring apparatus shown in FIG. 2, (B) is a BB line arrow directional view. It is a top view which shows the tube thickness measuring apparatus which concerns on 2nd Embodiment of this invention. It is a sectional side view which shows the pipe thickness measuring apparatus which concerns on 2nd Embodiment of this invention. (A) is a top view which shows the tube thickness measuring apparatus which concerns on 3rd Embodiment of this invention, (B) is a side view. It is a sectional side view which shows the tube thickness measuring apparatus which concerns on 3rd Embodiment of this invention. It is a sectional side view which shows the pipe thickness measuring apparatus which concerns on 4th Embodiment of this invention. It is a sectional side view which shows the pipe thickness measuring apparatus which concerns on 5th Embodiment of this invention. It is the sectional view on the AA line of the tube thickness measuring apparatus shown in FIG. It is a schematic block diagram which shows a boiler. It is a perspective view of the heat exchanger tube which has a flaw part. It is a figure explaining the thickness measurement of the crack part of a heat exchanger tube.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.

  As shown in FIG. 1, a tube thickness measuring device 1 according to an embodiment of the present invention is a device that measures the thickness of a tube 50 by ultrasonic flaw detection from the outer surface of the tube 50, and fills the jig body 2. The thickness of the tube 50 is measured by the water immersion type ultrasonic probe 10 through the contact medium. This tube thickness measuring apparatus 1 is particularly preferably used for measuring the thickness of the heat transfer tube 50 of the boiler 100 as shown in FIG. 11, and among them, the tube thickness of the damaged portion 51 such as a flaw or a dent in the heat transfer tube 50. It is more preferably used when the thickness is measured locally. In the first to fifth embodiments described below, the case of measuring the thickness of the heat transfer tube 50 of the boiler 100 will be described as an example. However, the present invention is not limited to this, and the thickness measurement of the tube is generally performed. Can be used.

(First embodiment)
With reference to FIG.2 and FIG.3, the structure of the tube thickness measuring apparatus 1 which concerns on 1st Embodiment of this invention is demonstrated. 2 is a side sectional view showing the tube thickness measuring apparatus according to the first embodiment of the present invention, and FIG. 3A is a sectional view taken along line AA of the tube thickness measuring apparatus shown in FIG. (B) is a BB line arrow view.
The tube thickness measuring apparatus 1 is mainly interposed between a local water immersion type ultrasonic probe 10, a jig body 2 that holds a contact medium, a jig body 2, and a heat transfer tube 50. A seal member 3, medium injection means 4 for injecting a contact medium into the jig body 2, and fixing means for fixing the jig body 2 to the outer surface of the heat transfer tube 50 are provided.

The local water immersion type ultrasonic probe 10 is a vertical probe, transmits or receives ultrasonic waves from an ultrasonic transmission / reception surface facing a contact medium, and an object to be inspected based on the received reflected waves. This is a well-known device for measuring the wall thickness of a steel sheet.
Examples of the contact medium include water, glycerin paste, and machine oil. Preferably, the contact medium is water mixed with a thickener. As this thickener, a cellulose-based water-soluble polymer as a main component can be used, and examples thereof include CMC Daicel (trade name: manufactured by Daicel Chemical Industries, Ltd.). More preferably, the contact medium has a viscosity in the range of 0.1 to 10P. This is because when the viscosity is less than 0.1 P, the contact medium easily leaks from the jig body 2, and when the viscosity is 10 P or more, bubbles tend to remain in the contact medium. Hereinafter, the contact medium is abbreviated as a medium.

  The jig body 2 includes a cylinder 21 that forms a medium space filled with a medium therein, and an opening 22 that is provided at one end of the cylinder 21 and has a curvature corresponding to the outer surface of the heat transfer tube 50. And a holding portion that is provided on the other end side of the cylindrical body 21 and holds the ultrasonic probe 10 and a lid portion 23 that seals the medium space.

The cylindrical body 21 is formed in a cross-sectional square shape or a circular cross-sectional shape, but is preferably a cross-sectional square shape as shown in the figure. This is because it is easy to form the opening 22 of the cylindrical body 21 with a curvature along the outer peripheral surface of the heat transfer tube 50. Moreover, it is preferable that the cylinder 21 is transparent or semi-transparent so that the medium with which the inside is filled is visible. Examples of the material of the cylindrical body 21 include vinyl chloride resin and acrylic resin, and these materials are suitable because they have good processability and can be reduced in weight. The cylindrical body 21 is good to have heat resistance performance in a temperature range of at least 5 to 50 ° C.
The opening 22 is formed with a curvature corresponding to the outer surface of the heat transfer tube 50, but does not necessarily need to be completely coincident, and the space between the outer surface of the heat transfer tube 50 and the cylindrical body 21 is compensated by the seal member 3. Any curvature range is acceptable.

The holding part may be an ultrasonic probe insertion hole 24 formed in the lid part 23, and the ultrasonic probe 10 is held by inserting the ultrasonic probe 10 into the insertion hole 24. To do.
In addition, the holding unit may include a guide plate 25 that supports the periphery of the ultrasonic transmission / reception surface of the ultrasonic probe 10. The guide plate 25 is installed in the medium space, and a hole portion 26 is provided in a portion corresponding to the ultrasonic wave transmitting / receiving surface of the ultrasonic probe 10, and ultrasonic waves are transmitted or received from the hole portion 26. Yes. A counterbore 27 is formed at the periphery of the hole 26, and the ultrasonic probe 10 is positioned by fitting the ultrasonic wave transmitting / receiving surface to the counterbore 27. The guide plate 25 keeps the distance from the ultrasonic transmission / reception surface to the opening 22 constant, and fixes the angle of the ultrasonic transmission / reception surface.

  Moreover, it is preferable that the medium space in the cylinder 21 is partitioned into two spaces, a first medium space 201 and a second medium space 202, by the guide plate 25. A medium is injected from the medium injection means 4 into the first medium space 201. An air hole 204 is provided in the second medium space 202. The guide plate 25 is provided with a minute gap 203 through which air and a medium circulate. When the medium is injected into the first medium space 201, the air is transferred from the first medium space 201 to the second medium space 202. Further, the air is discharged from the second medium space 202 to the outside through the air hole 204. The medium is filled in the first medium space 201 without any gap, and at this time, the medium is injected into the first medium space 201 until the medium slightly leaks from the minute gap 203 into the second medium space 202. It is possible to ensure water immersion in one medium space 201.

  In the minute space 203, the hole 26 is formed slightly larger than the outer diameter of the ultrasonic probe 10, and air or a medium passes through the gap 26 between the hole 26 and the ultrasonic probe 10. It may be allowed to flow, or a new hole may be formed in the guide plate 25 as shown. Similarly, in the air hole 204, the ultrasonic probe insertion hole 24 is formed slightly larger than the outer diameter of the ultrasonic probe 10, and a gap between the probe insertion hole 24 and the ultrasonic probe 10 is used. Then, air may flow from here, or a new hole may be formed in the lid portion 23 as shown.

  The seal member 3 is formed in an annular shape and is disposed along the edge of the opening 22 of the cylindrical body 21. The sealing member 3 may be a separate member that is not fixed to the cylindrical body 21. In this case, the jig body 2 is fixed in a state where the sealing member 3 is interposed between the cylindrical body 21 and the heat transfer tube 50. The sealing member 3 is fixed by pressing with. More preferably, the seal member 3 is fixed to the opening 22 of the cylindrical body 21. As a result, the seal member 3 can be prevented from shifting when the jig body 2 is grounded to the heat transfer tube 50.

  The seal member 3 is made of a rubber O-ring such as a silicon bag, a string base, polyurethane, or silicon rubber formed in an annular shape. Furthermore, the seal member 3 may be provided so as to be positioned inside the cylinder 21, and the outer periphery of the opening 22 of the cylinder 21 may be double-sealed by the outer seal member. Examples of the outer seal member include a viscosity, a silicone sealant, and a rubber impression material.

The medium injecting means 4 has a configuration in which the medium is pumped from the container 42 containing the medium by the pumping means to the injection pipe 41 and this medium is injected into the medium space in the cylindrical body 2 through the injection pipe 41. . For example, a syringe-like instrument comprising a cylinder and a piston is used for the container 42 and the pressure feeding means. The injection tube 41 is made of a flexible material such as resin, and for example, a silicon tube is used. The injection tube 41 may be installed through the lid portion 23 and the guide plate 25 as shown in FIG. 2, or installed through the side surface of the cylindrical body 21 as shown in FIGS. 9 and 10. Also good.
Returning to FIGS. 2 and 3, the medium injection means 4 preferably seals the injection tube 41 with a clip 45 when the injection tube 41 is not used, and maintains the medium space in a substantially sealed state.

The fixing means is to fix the jig body 2 to the outer surface of the heat transfer tube 50. For example, a string base in which magnetic powder is mixed into the seal member 3 to give a magnetic force is used. The jig body 2 is fixed to the heat transfer tube 50 by this string-based adsorption force. Since the heat transfer tube 50 is made of a magnetic material such as carbon steel or low alloy steel, the jig body 2 can be fixed to the heat transfer tube 50 by the magnetic force of the string base.
In this way, the string base is attached to the edge of the opening 22 of the cylindrical body 21, and the sealing member 3 and the fixing means are integrated by providing the string base with functions of preventing medium leakage and fixing the jig body 2. Therefore, the apparatus configuration can be simplified and downsized. Moreover, the jig body 2 can be easily attached and detached by adopting a configuration in which the jig body 2 is attracted to the outer surface of the heat transfer tube 50 by magnetic force.

The operation of the tube thickness measuring apparatus 1 having the above-described configuration will be described.
First, the opening 22 of the jig body 2 is brought into contact with the outer surface of the heat transfer tube 50 via the seal member 3, and the jig body 2 is fixed to the heat transfer tube 50 by a fixing means. Then, the medium is injected into the first medium space 201 of the jig body 2 by the medium injection means 4. As the medium is injected, the air in the first medium space 201 passes through the minute gap 203 and is discharged to the outside through the second medium space 202 and further through the air hole 204. The medium is injected by the medium injection unit 4 until the first medium space 201 is filled with a medium without any gap, and when the medium starts to leak into the second medium space 202, the injection operation is stopped. By this injection operation, the medium is held in the first medium space 201 in a state of being in direct contact with the outer surface of the heat transfer tube 50 through the opening 22.

Then, an ultrasonic wave is transmitted from the ultrasonic probe 10, the ultrasonic wave passes through the medium and enters the heat transfer tube 50 from the opening 22, and the reflected wave reflected by the inner peripheral surface of the heat transfer tube 50 is detected by the ultrasonic probe. Received by the tentacle 10 Based on the received reflected wave, the thickness of the heat transfer tube 50 is detected.
When the thickness detection is completed, the jig body 2 may be removed from the heat transfer tube 50 and the medium may be discharged, or the medium may be sucked by the medium injection means 4 before the jig body 2 is removed.

  As described above, according to the present embodiment, the medium filled in the medium space of the cylinder 21 is directly brought into contact with the outer surface of the heat transfer tube 50 from the opening 22 of the cylinder 21. Even if there is a damaged portion 51 such as a scratch or a dent, the medium enters the irregularities of the damaged portion 51, and ultrasonic flaw detection can be performed with high accuracy. Further, since only the medium is interposed between the ultrasonic probe 10 and the heat transfer tube 50, the reflected wave required for the thickness measurement can be easily detected, and the thickness measurement can be performed accurately and easily. Can do. Further, since the thickness of the heat transfer tube 50 is directly measured by the ultrasonic probe 10, it is possible to reduce measurement errors and easily determine whether or not the heat transfer tube 50 needs to be repaired from the measurement result of the tube thickness. Become. Furthermore, the opening 22 of the cylindrical body 21 is formed with a curvature corresponding to the outer surface of the heat transfer tube 50, and the seal member 3 is interposed between the edge of the opening 22 and the outer surface of the heat transfer tube 50. Therefore, the medium filled in the medium space can be prevented from leaking from the opening 22.

(Second Embodiment)
With reference to FIG.4 and FIG.5, the pipe | tube thickness measuring apparatus which concerns on 2nd Embodiment of this invention is demonstrated. Here, FIG. 4 is a plan view showing a tube thickness measuring apparatus according to the second embodiment, and FIG. 5 is a side sectional view thereof.
In the following second to fifth embodiments, detailed description of the same configurations as those of the first embodiment will be omitted.

This tube thickness measuring apparatus 1 has a configuration in which the magnet base 6 is used as a fixing means in the configuration of the first embodiment described above.
The magnet base 6 is attached to the outer peripheral surface of the cylindrical body 2, and the jig body 2 is fixed to the heat transfer tube 50 by its adsorption force. As the magnet base 6, for example, a permanent magnet or a coil is housed therein, and a magnet base 6 whose generation of magnetic force is controlled by an ON-OFF switch is used. When the thickness is measured, the jig body 2 is fixed to the heat transfer tube 50 by setting the switch to ON. When the thickness measurement is completed, the jig body 2 can be detached from the heat transfer tube 50 by switching to OFF. .

As shown in FIG. 4, the magnet base 6 is preferably attached at a position sandwiching the opposed surfaces of the cylindrical body 21, so that the jig body 2 can be stably fixed to the heat transfer tube 50. it can. Of course, the magnet base 6 may be attached only to a part of the cylinder 21 or may be attached so as to surround the circumference of the cylinder 21.
Furthermore, as shown in FIG. 5, the end of the magnet base 6 on the side in contact with the heat transfer tube 50 may have a cutout portion 61 cut out in a V shape. The V-shaped notch 61 allows the heat transfer tube 50 and the magnet base 6 to contact each other at least at two locations so that the jig body 2 can be stably fixed, and the magnet base 6 can be mounted even when the diameter of the heat transfer tube 50 is different. Can be used.

  According to the second embodiment described above, the magnet base 6 is attached to the outer peripheral surface of the cylindrical body 21, and the jig base 2 is fixed to the outer surface of the heat transfer tube 50 by the magnet base 6, thereby further strengthening the structure. The jig body 2 can be fixed to the outer surface of the heat transfer tube 50. In addition, the jig body 2 can be easily attached and detached by using the magnet base 6 to attract the jig body 2 to the outer surface of the heat transfer tube 50 by magnetic force.

(Third embodiment)
With reference to FIG.6 and FIG.7, the pipe | tube thickness measuring apparatus which concerns on 3rd Embodiment of this invention is demonstrated. Here, FIG. 6 (A) is a plan view showing a tube thickness measuring apparatus according to the third embodiment of the present invention, (B) is a side view, and FIG. 7 is according to the third embodiment of the present invention. It is a sectional side view which shows a tube thickness measuring apparatus.
The tube thickness measuring apparatus 1 has a configuration in which the magnet base 6 is used as a fixing means in the configuration of the first embodiment described above, and the magnet base 6 is fixed to the jig body 2 by a fixing member 7. It has become.

The magnet base 6 has the same configuration as that of the second embodiment described above.
The fixing member 7 is formed in an L shape, one end side is joined to the magnet base 6, and the other end side is fixed to the lid portion 23 side of the cylindrical body 2 with a fastening member 8 such as a bolt. Further, the other end side of the fixing member 7 has a shape in which a portion where the ultrasonic probe 10 is disposed is opened.
According to the third embodiment described above, the jig body 2 is fixed to the heat transfer tube 50 by the magnet base 6, and the jig body 2 is moved from the lid portion 23 side to the heat transfer tube 50 side by the L-shaped fixing member 7. Since it is pressed, the jig body 2 can be fixed more stably than in the second embodiment.

(Fourth embodiment)
With reference to FIG. 8, a pipe thickness measuring apparatus according to a fourth embodiment of the present invention will be described. Here, FIG. 8 is a side sectional view showing a tube thickness measuring apparatus according to the fourth embodiment of the present invention.
This tube thickness measuring apparatus 1 has a configuration using an annular magnet base 6 as a fixing means in the configuration of the first embodiment described above. At this time, since the magnet base 6 is present on the outer peripheral surface of the cylindrical body 21, the seal member 3 is attached to a position that is accommodated in the cylindrical body 21. In the case where the seal member 3 is disposed inside the cylindrical body 21, a silicon bag is preferably used as the seal member 3.
According to the above-described fourth embodiment, the apparatus configuration can be simplified and it can be manufactured at low cost.

(Fifth embodiment)
With reference to FIG.9 and FIG.10, the pipe | tube thickness measuring apparatus which concerns on 4th Embodiment of this invention is demonstrated. Here, FIG. 9 is a side sectional view showing a tube thickness measuring apparatus according to a fifth embodiment of the present invention, and FIG. 10 is a sectional view taken along line AA of the tube thickness measuring apparatus shown in FIG. .
In the tube thickness measuring apparatus 1, in the configuration of the first embodiment described above, the ultrasonic probe 10 is held in a state where the distance between the ultrasonic probe 10 and the outer surface of the heat transfer tube 50 is kept constant. A mechanism for sliding is further provided.

  As shown in FIG. 10, the holding portion of the ultrasonic probe 10 is constituted by a guide plate 25, and the ultrasonic transmission / reception surface of the ultrasonic probe 10 is fitted to a countersink portion 27 formed on the guide plate 25. By doing so, the ultrasonic probe 10 is positioned. Furthermore, it has the two guide rails 251 and 251 each attached to the inner surface which the cylinder 21 opposes, The guide board 25 is arrange | positioned so that these guide rails 251 and 251 may slide on this guide board 25 At the same time, the ultrasonic probe 10 slides. Here, the ultrasonic probe 10 is configured to slide in the axial direction of the heat transfer tube 50, but the ultrasonic probe 10 may be configured to slide in the circumferential direction of the heat transfer tube 50. .

On the other hand, the lid portion 23 is formed of a sheet material 231 so that the medium space can be sealed even if the ultrasonic probe 10 slides. Specifically, a sheet material 231 in which an ultrasonic probe insertion hole 233 into which the ultrasonic probe 10 is inserted is formed in the lid portion 23 is used. As the sheet material 231, for example, a waterproof sheet such as vinyl or Teflon (registered trademark) sheet is used. The outer peripheral edge of the sheet material 231 is bonded and fixed to the inner peripheral surface of the cylindrical body 21, and the edge of the ultrasonic probe insertion hole 233 is fixed to the outer peripheral surface of the ultrasonic probe 10 so that the medium does not leak. To. At this time, the edge of the ultrasonic probe insertion hole 233 of the sheet material 231 may be bound to the outer peripheral surface of the ultrasonic probe 10 and fixed by an annular rubber such as a rubber band or an O-ring. When the sheet material 231 is used, the injection tube 41 of the medium injection unit 4 is installed in the medium injection port 43 provided on the outer peripheral surface of the cylindrical body 21.
In this way, the ultrasonic probe 10 has a mechanism that slides in the axial direction of the heat transfer tube 50, for example, so that the flaw detection range can be expanded within the range in which the cylindrical body 21 abuts.

DESCRIPTION OF SYMBOLS 1 Tube thickness measuring apparatus 2 Jig body 3 Seal member 4 Medium injection | pouring means 6 Magnet base 7 Fixing member 8 Fastening member 10 Ultrasonic probe 21 Cylindrical body 22 Opening part 23 Cover part 24 Ultrasonic probe insertion hole 25 Guide plate 26 Hole 27 Countersink 50 Heat transfer tube 201 First medium space 202 Second medium space 203 Minute gap 204 Air hole 231 Sheet material

Claims (6)

In a tube thickness measuring device that measures the thickness of a tube by ultrasonic flaw detection,
A local water immersion ultrasonic probe,
A cylinder forming a medium space filled with a contact medium, an opening provided at one end of the cylinder and having a curvature corresponding to the outer surface of the tube, and provided at the other end of the cylinder A jig body having a holding part for holding the ultrasonic probe and a lid part for sealing the medium space;
A seal member interposed between an edge of the opening and an outer surface of the tube;
Medium injection means for injecting the contact medium into the medium space;
Fixing means for fixing the jig body to the outer surface of the pipe,
A tube thickness measuring apparatus for measuring the thickness of the tube by the ultrasonic probe in a state where the jig body is fixed to the outer surface of the tube by the fixing means via the seal member. .   The fixing means is a string base in which magnetic powder is mixed into the seal member to give a magnetic force, and the jig main body is fixed to the tube formed of a magnetic material by the attraction force of the string base. The pipe wall thickness measuring device according to claim 1.   The fixing means is a magnet base attached to the outer peripheral surface of the cylindrical body, and the jig main body is fixed to the tube formed of a magnetic body by an attractive force of the magnet base. The pipe wall thickness measuring apparatus according to claim 1.   The said holding | maintenance part contains the guide plate which supports the circumference | surroundings of the ultrasonic transmission / reception surface of the said ultrasonic probe, and hold | maintains the distance from the said opening part to the said ultrasonic transmission / reception surface uniformly. The tube thickness measuring apparatus as described in any one of thru | or 3.   The medium space is partitioned into two spaces that communicate with each other with a minute gap by the guide plate, and the contact medium is injected from the medium injection means into the first medium space formed on the opening side. The tube thickness measuring apparatus according to claim 4, wherein an air hole is provided in the second medium space formed on the lid side. The said holding | maintenance part has a mechanism to which the said ultrasonic probe is slid and moved in the state which kept the distance with the outer surface of the said pipe | tube constant, The Claim 1 thru | or 5 characterized by the above-mentioned. Tube wall thickness measuring device.

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