JPS58117451A - Ultrasonic inspection device - Google Patents

Abstract

PURPOSE:To simplify constitution of an ultrasonic inspection device with longitudinal tubes and improve the inspection accuracy and workability, by a method wherein an axial drive member and a circumferential drive member are distributed in the axial direction, and only probes are partly immersed in water. CONSTITUTION:A probe inserting mechanism 34 is composed of a plurality of connecting tubes 24 containing electric wirings and pipings for water and air, a probe member 21 comprising a plurality of probes, a drive member 22 in the axial direction, a drive member 23 in the circumferential direction, a rubber ring 26 for water seal, and a connecting member 25 for connecting electric wirings and pipings for water and air in the connecting tubes 24. The probe drive device 34 is inserted in a housing 4 without impressing air pressure to a rubber ring 26 and connected by the connecting member 25 in sequence and fixed to a flange 11 at lower end of the housing 4 by a flange 36. Then air pressure is impressed to the rubber ring 26 thereby the probe drive device is closely contacted with inside of the housing 4 so as to perform water seal. Water is fed to upper part of the rubber ring 26 by a pump 30 and a liquid surface 27 is constituted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrasonic inspection device for vertical tubes used in plants such as nuclear power plants, and in particular, the present invention relates to an ultrasonic inspection device for vertical tubes used in plants such as nuclear power plants. The present invention relates to a probe driving device for scanning.

As the hook of the vertical tube body, the hook for driving the control rod of the pressure vessel in the boiling water reactor as shown in Fig. 1 is used.
(RDH) and neutron measurement (ICMH). To explain the outline of the structure from FIG.
, a flange 7 for attaching the upper mirror 2 combined with this, and a lower mirror 3 welded to the lower part of the pressure vessel body 1.
It consists of a housing 4 and a skirt 9 for driving control rods and for measuring neutrons, which are welded to the lower mirror 3.

Further, around the pressure vessel body, there is a heat insulator 5 and a gun shield 6. The housing 4 is shown in detail in FIG. 2. In particular, the housing for neutron measurement is shown, but the shape of the housing for driving the control rods is almost the same, although the inner diameter is larger.

FIG. 2 is an enlarged view of the housing, and shows the welded part 12 between the lower boundary 3 of the pressure vessel and the housing 4.
The two locations near the welded portion 13 between the housing 4 and the seventh flange 11 are to be inspected.

For this reason, when inspecting, it is conceivable to insert a probe into the housing 4 and conduct the ultrasonic inspection from the inner surface.

However, in reality, it is very difficult to inspect because the inner diameter of the pipe is small and the length of the housing 4 is about 4 m compared to the inner diameter.

In particular, it is very difficult to inspect a neutron measurement housing because its inner diameter is approximately 38φ.

When such a vertical tube is operated remotely and automatically inspected, the scanning direction of the probe needs to be moved in the axial direction and circumferential direction of the tube. Therefore, as for the mounting method of the drive device, (1) the axial and circumferential drive parts are mounted on the outside of the pipe body, that is, below the 7 flange 11 in Fig. 2; Insert one of them into the pipe near the inspection point, and attach the other drive part to the outside of the pipe body, (3)
There are three methods: one in which both the axial and circumferential drive parts are mounted near the inspection point inside the tube. Method (1) makes it easier to design and manufacture the drive unit because there is no space restriction, but the driving force increases because it moves the entire 4m, and the 4m length makes transportation and handling difficult. It is necessary to divide the probe into two parts, and there are drawbacks such as drive delays due to backlash and distortion, increased position detection errors, and decreased positioning accuracy of the probe. Method (2) is
Japanese Patent Application Laid-Open No. 52-72274 (Patent Application No. 50-147422)
This is a system in which the axial drive section is placed under the flange and the circumferential drive section is placed inside the pipe. This drawback is
As with the previous reason, the axial positioning accuracy is reduced, and the distance between the drive parts makes it difficult to handle.Furthermore, when moving in the axial direction, it is driven against gravity, so the inside of the pipe is The driving force must be increased because it is affected by the weight of the driving part, etc.

Therefore, when this system is fully adopted, it is advantageous to put the axial drive section inside the pipe and the circumferential drive section outside, since it will not be affected by weight. In the method (3), since the shaft and the circumferential drive section can be arranged near the probe, backlash and bulging can be minimized, and positioning accuracy is improved. Furthermore, since the configuration of the device is simplified, it can be made smaller and lighter. However, the disadvantage of this is that it is difficult to design and fabricate the device due to limited space. especially,
Since the inner diameter of the neutron measurement housing is approximately 38φ,
It is very difficult to put the drive part inside this.

When performing ultrasonic testing, it is necessary to use a couplant such as water to improve the transmission of ultrasonic waves between the probe and the subject. Methods for supplying this couplant between the probe and the subject include (1) a method of flowing water between the probe and the subject, and (2) a method of immersing the probe and the subject in water. There is.

The method α) has the advantage that the amount of water can be reduced because water is circulated, and that waterproofing measures are relatively easy. but,
If the sample is thin, such as a neutron measurement housing, air can be easily entrained in the water, and if the probe is brought into contact with the sample, the probe may not be able to be used in areas that cannot be used ultrasonically. There are drawbacks such as the need to keep the distance between the patient and the subject, and this method cannot be used.

Method (2) is ultrasonically stable, but since the water used here is treated as contaminated water, increasing the amount of water means increasing the amount of treated water, which is not desirable. That's not the point. Furthermore, if the drive unit is placed inside the pipe, measures such as waterproofing will be required.

In accordance with the American ACMB standard, the incident angle of ultrasonic waves is 0'''
, 45'' and 60''. Therefore, it is necessary to inspect these angles, but it is difficult to attach and detach the device at each angle.
Not practical. Therefore, it is necessary to implement a probe with three angles, or to use a variable angle probe whose incident angle can be changed remotely. Furthermore, these ultrasonic beams need to be able to be incident both in the axial direction and in the circumferential direction.

Furthermore, when these probes are mounted, there is a possibility that they may not be mounted at the correct angle, so it is practically effective to be able to adjust the angle to some extent.

The length from the 7 lange 11 to the welding part 12 in Figure 2 is approximately 4
Since the length is 1.5 m, the space for transporting the test site to the inspection site is narrow, making it difficult to transport and handling during attachment and detachment. In addition to the welded portion 12, the welded portion 13 near the flange 11 is also inspected, and it is desirable that both inspection points be able to be inspected with one inspection device. Furthermore, since the lower mirror 3 has a curvature, the distance from the flange 11 to the welded portion 12 changes. Therefore,
It is necessary to be able to follow and inspect this change. One effective way to deal with this is to lengthen the scanning stroke in the axial direction, but this has the disadvantage of increasing the size of the device.
A simple method is required.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art described above and to provide an ultrasonic inspection apparatus having a simple configuration and a small probe insertion mechanism.

To achieve the above object, the present invention employs a configuration in which the axial drive section and the circumferential drive section are distributed and arranged in the axial direction, and only the probe is partially immersed in water. In the optimal embodiment described below as a specific method of this partial water immersion method, a rubber ring that expands and contracts by external air pressure operation is placed on the top of the circumferential drive section, and when inspecting, this is used. When air pressure is applied, the rubber expands and comes into contact with the inner surface of the tube to create a water seal. - On the other hand, the couplant water is fed through a pipe that opens at the top of the rubber ring, overflows through a pipe provided below the axial drive part, and is taken out to the outside. This allows a constant liquid level to be created. That is, the area from the rubber ring to the top of the pipe can be filled with water. When taking the probe, probe drive means, etc. outside, remove the water from the pipe into which it was introduced, and then release the air pressure in the rubber ring to remove it from the inner surface of the tube. It can be taken out. In addition, the probe is a multi-probe system in which 06, 45” and 60° are arranged in the axial direction and circumferential direction.
The probe insertion mechanism is designed so that it can be divided into a plurality of parts in the length direction.

An example of the configuration of a remote automated skin ultrasound examination device is shown in FIG. Third
The figure shows an example where the housing is applied to a small-diameter housing such as the No-Uji Puffer for neutron measurements. transmitting and receiving ultrasonic signals to and from a control device 28 for controlling the running of the probe section 21 and displaying its position information, which is installed at It is comprised of a display device 29 for displaying the test results of the subject online in the form of a cross section or a plane based on the received signal and the position information from the control device 28. In addition, there is a pump 30 for sending water used as a couplant, a water tank 31 for temporarily receiving the returned water, and a compressor 32 for sending air pressure to the rubber ring 26 for sealing the water. , connected to the inspection position by each pipe.

The distance of the probe insertion mechanism 34 attached to the seventh flange 11 of the housing 4 from the seventh flange 11 of the welding portion 12 changes due to the curvature of the lower mirror 3. This distance can be known in advance by a nozzle 4 attached to the lower mirror 3. For this reason, it is necessary to operate the screw 35 in advance to insert the probe into the probe insertion mechanism 3.
Positioning can be performed by sliding 4.

The probe insertion mechanism 34 includes a plurality of connecting pipes 24 containing power wiring and water and air piping, a probe section 21 consisting of a plurality of probes, and a driving section 22 in the -axial direction. It is composed of a circumferential driving part 23, a rubber ring 26 for water sealing, and a connecting part 25 for connecting electrical wiring such as a connecting pipe 24, and water and air piping. When inserting the probe drive device 34 into the nozzle blowfish 4, it is inserted without applying air pressure to the rubber ring 26, and the probe drive device 34 is inserted into the rubber ring 26 while being connected through the connecting portion 25. 4 is fixed to the 7 flange 11 at the lower end. After this,
By applying air pressure to the rubber ring 26, it is brought into close contact with the inner surface of the housing 4 to perform water sealing. Furthermore, water is sent to the upper part of the rubber ring 26 by the pump 30, and the liquid level 2
Make 7. That is, an over surface 70 is provided at the position of the liquid surface 27.

Therefore, the space between the rubber ring 26 and the liquid surface 27 can be immersed in water, and the probe section 21 moves while being immersed in water.

FIG. 4 shows details of the axial drive section 22 and probe section 21 shown in FIG. 3. The probes include a probe 63 with a refraction angle of 0'' when inspecting in the axial direction, a probe 62 with a refraction angle of 45'' and a probe 64 with a refraction angle of 60'', as well as probes with a refraction angle of 60'' when inspecting in the circumferential direction. A probe 65 with a refraction angle of 45'' and a probe 65 with a refraction angle of 60' are placed on the holder 61. When inspecting in the axial and circumferential directions, it is possible to carry out the inspection at the same time. , are usually carried out separately.For this reason, in the case of circumferential inspection, the probe 63 is used to reduce the number of probes and secure space. The probes 62, 63, 64, and 65, 66 are each mounted concentrically, and the refraction angles of all of them can be adjusted concentrically by screws 67, which are normally adjusted before installation. It is also effective when inspecting at other refraction angles.The holder 61 is connected to the motor 5 in the axial direction.
2 to rotate the shaft 57. This rotation is transmitted from the female screw 60 to the male screw 58, but since the movement of the female screw 60 in the axial direction is restricted, the male screw 58 moves up and down as it rotates. Also, in order to restrict movement in the circumferential direction, the two balls 56 are attached to the bearing 5 together with the male screw 58.
It slides in contact with 9. The holder 61 has this male screw 5-8.
Since it is integrated with the ball 56, the nousing 4
move in the axial direction. Accordingly, the probes 62, 63° can be scanned in the 64, 65, 66i axis direction. When the vicinity of the holder 61 is viewed from the side, it is shown that the holder 61 moves in the axial direction as shown in FIG. 5, and moves like the holder 61A.
In this case, the probes 62, 63, 64, and 66 are all immersed in water, and the water for the couplant sent from the bottom is
- It rises inside the Ujifugu 4, overflows from the pipe 79, and is led to the lower part. Therefore, a free liquid level is formed at the upper end of the pipe 79, but the liquid level can be kept at a constant position by controlling the flow rate to be fed.

If the object to be examined is thin, it cannot be inspected by contacting the inner surface of the housing 4 due to the characteristics of ultrasonic waves. Therefore, the probes 62, 63, 64, 66 need to be installed at a certain distance from the inner surface of the housing 4.

The ball 51 in FIG.
This is provided to prevent the parts 01 from coming into contact with each other and to operate smoothly when inserted into the nousing and when moved in the circumferential direction. This part is shown in detail in FIG. 6. That is, the balls 51, 71, and 76 are arranged along the circumference at equal intervals, and are in contact with the inner surface of the housing 4. One of these balls 71
The body 72 is constantly pushed out by the spring 73. This is because there is an error in the inner diameter of the Nouji Puffer 4 due to manufacturing etc., so this is accommodated so that the balls 51, 71, 76 are always in contact with each other.

FIG. 7 shows the detailed mechanism of the local direction drive unit 23 and rubber ring 26 shown in FIG. 3. The probe section and the axial drive section are connected to each other by a case 101 that is integrated with the probe section and the axial drive section within the I.Ujifugu 4. The couplant water rises from the pipe 84 over the inner surface of the case 101 and the tube 4, enters the probe section 21, and overflows L at the upper end of the nozzle tube 79. ; It passes through the tube 79, is taken out to the outside through the hole 89, and the pipe 91, and is returned to the water tank 31 in FIG. Water tank 31
The water returned to the tank is again sent to the nozzle 84 in FIG. 7 by the pump. The water used in the couplant is thus continuously circulated in a closed loop. Water sealing of the housing 4 is achieved by applying air pressure to the inside of the rubber ring 26 to inflate it and bring it into contact with the inner surface of the housing 4. Air pressure is introduced from the tube 88 that has passed through the compressor. When taking the probe etc. out of the Ujifugu 4, the air pressure in the rubber ring 26 is reduced by releasing the pulp provided outside. This can be done by pulling it out, shrinking it, and separating it from the inner surface of the maggot pufferfish 4.

From FIG. 7, the cable 86 to the probe part 21 and the axial drive part thereon is shown in a bottle in a space where the cable 80 of the probe part 21 is water-sealed by a rubber bushing 83 and another rubber bushing 81. 82. This space is also filled with expanded fat to strengthen the water seal.

The cable 80 is housed in a single case and wound in a spiral so that the probe section 21 moves in the axial direction. On the other hand, the cable to the axial drive section branches from the point where it exits from the rubber bush 87, passes through a pipe 79 for passing overflow water, and is routed to the upper drive section.

The circumferential drive unit is fixed within the case 102, and its operating mechanism controls the rotation of the motor 100 by gears 97 and 9.
6 to the shaft 98.

During the rotation, a potentiometer 99 is rotated from the shaft 98 via the gears 95 and 94, and the potentiometer 99 can send rotation angle information in the circumferential direction to the control device. On the other hand, the rotation of the shaft 98 is controlled by the gear 9
2. It is transmitted to the shaft 90 integrated with the case 101 via the gear 93, and as a result, it is possible to give a circumferential movement to the axial drive section connected to the upper probe section 21 and the case 101. can. Furthermore, in order to avoid cutting the cable 85, the driving in the circumferential direction is limited to a range that can be inspected all around. Note that the pipes 91 and 84 are cut in the middle, but this may be done by placing them at different positions in the circumferential direction or by using a vinyl tube or the like from the middle to connect the motor 100 and gear. It is located at a distance of 95.94 mag.

In order to prevent the case 102 from coming into contact with the inner surface of the housing 4, rollers 110, 1 as shown in FIG.
14 were arranged at equal intervals in the circumferential direction. This roller 140
．． 114 is the shaft 111, 113 only when inserted.
, 117, and is in contact with the inner surface of the housing 4 after installation. This row 2114 is also pressed against the inner surface of the housing 4 by the spring 112 in order to cope with manufacturing errors in the inner diameter of the housing 4.

In this way, the distance between the inner surface of the housing and the probe can be kept constant by the balls 51, 76, 71 shown in FIG. 6 and the rollers 110, 116, 114 shown in FIG. 8 at the tips.

A specific example of the connection portion 25 shown in FIG. 3 is shown in FIG.

Both are connected by a union nut 134 of the case 130 and a screw 137 of the case 129. Accordingly, the water and air pipe 122 and the pipe 121 and the electric system socket 136 and the bottle 135 can be connected.

In this case, O-ring 12 is used to seal water and air.
8 and an O-ring 12 for sealing water etc. from the outside.
7 is provided. In addition, the pipe 121 is connected to the bushing 13.
2, the pipe 122 and the socket 136 are fixed by the bush 131. Even if water leaks from the pipes 121 and 122 of the water system when the bushing 133Fi fixing the bottle 135 and the case 129 and the case 130 are separated, the bottle 135 and the socket 136
In order to prevent water from entering the bushing 132, the cable 125 is slidably extended from the bushing 132. For this reason, the water and air system pipes 121 and 122 and the electrical system bottle 135 and socket 136 are separated in two stages. In addition, inside the case 130° 129, there are tubes 124 and 123 connected to the pipe 121 and the pipe 122, respectively.

This connecting portion is shown in cross section as shown in FIG.

The outer bushing 132 has a pipe 141 for supplying water and a pipe 1 for guiding overflow water to the outside.
42 and a pipe 143 for supplying air pressure. Further, a bin 136 (or socket) for electrical wiring is arranged in the inner bush 133. Coaxial cables can be connected to the bins and sockets in this example for miniaturization.

In the case of the above-mentioned embodiment, the following features are abundant, and the test accuracy, operability, expansion of the test range, and reduction in the amount of couplant can be greatly improved.

1) Even in a test object with a small inner diameter, such as a neutron measurement housing, the drive section in the probe direction and circumferential direction can be placed near the inspection point. As a result, it is possible to reduce not only the size but also the positioning accuracy and driving force.

2) We adopted a partial immersion method in which only the scanning range of the probe was immersed in water, and in order to achieve this we installed a rubber ring and an overflow tube that could be remotely sealed with water from the outside.

As a result, a complete water seal can be achieved in the middle of the pipe, and the liquid level can be kept constant with an extremely small flow rate, making it possible to significantly reduce the amount of couplant. Furthermore, since the number of contact points with the couplant is minimized, reliability in waterproofing is improved. Further, by making the flow of the couplant in a closed loop, the amount of the couplant can be reduced in this aspect as well, and the amount of treated water can be extremely reduced. Furthermore, since it is a water immersion method, the position of the probe can be changed depending on the thickness of the specimen, and
Inspection accuracy is improved because air is not trapped.

3) In addition to the weld between the lower boundary and the housing, it is also possible to inspect the weld between the flange at the bottom end of the housing, which improves versatility.

4) Since the probe insertion mechanism can be divided into predetermined lengths, attachment/detachment operations and transportation are facilitated. In addition, in this division, water, pneumatic systems, and electrical systems can be easily connected and
Naeru. Furthermore, since all wiring and piping are housed inside the case, troubles such as friction and catching can be prevented.

5) The balls and rollers of the probe drive device arranged circumferentially at regular intervals allow the probe to slide smoothly inside the tube, thereby eliminating friction at other locations. Furthermore, since one of the balls and rollers is made slidable in the thickness direction of the tube, dimensional errors in the tube during manufacturing can be absorbed.

6) Since a rubber ring is used and it is operated by external pneumatic pressure, the expansion and contraction stroke of the rubber ring can be increased, and in this respect, it is also possible to follow the dimensional error of the pipe.

7) Probes can be arranged concentrically and adjusted concentrically. Therefore, in addition to being able to adjust the refraction angle to the inspection standard, the angle can also be adjusted depending on the shape and direction of the reflector.

The present invention is not limited to atomic couplants, but can also be applied to the inspection of other vertical tubes.

In the embodiment of the present invention, multi-probes were used, but
A single probe or a variable angle probe can be used depending on the inner diameter of the tube and the purpose of inspection.

In the embodiment of the present invention, a liquid layer is formed in the middle of the driving part, but it is also possible to form a liquid layer on both moving parts, as shown in FIG. 11, for example. As shown in FIG. 11, the probe 165 inserted into the housing 4 moves circumferentially and axially in a liquid layer 170 sealed by a rubber ring 171. , after being guided through pipe 66, pipe 1
67 and is taken out again. The rubber ring 171 is normally contracted and is away from the housing 4 surface, but when air pressure is applied from the outside via the pipe 169, the rubber ring 171 expands until it comes into contact with the housing 4 inner surface, thereby forming a water seal. . For axial driving, by rotating the screw 163 from the motor 159, the nut that is integrated with the probe and meshed with this screw can be moved in the axial direction. This movement is gear 1
62, position information is obtained by applying rotation to the potentiometer 160 by the gear 161 and converting this resistance change into a voltage signal and outputting it to the outside. On the other hand, for driving in the circumferential direction, the shaft 157 is rotated by the motor 150 via the gears 168 and 154.

Furthermore, the boss 1721 via the gear 155 and the gear 156
By rotating the motor 159 connected to this
, potentiometer 160, boss 173.174i can be rotated. This allows the probe 165 and pipe 167 to also move in the circumferential direction. This liquid phase 17
O-rings are included in all sliding parts such as the boss 174 and the lower part of the screw 163 that are in contact with the O-ring.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating the configuration of the vicinity of the pressure vessel of the atomic couplant, FIG. 2 is a schematic diagram of the neutron measurement and bracing rod drive housing, and FIG. 3 is the probe drive device of the present invention. 4 is an upper configuration diagram showing an embodiment of the device of the present invention, FIG. 5 is a side view of the probe section, and FIG. 6 is a diagram showing the structure of the ball in contact with the subject. 7 is a lower configuration diagram showing one embodiment of the present invention; FIG. 8 is a diagram showing the configuration of a roller in contact with a subject; FIG. 9 is a sectional view showing the configuration of a connecting part. , FIG. 10 is a circumferential configuration diagram thereof, and FIG.
The figure is a configuration diagram for explaining another embodiment. 3... Bottom condition, 4... Housing, 11... 7 lunge, 12, If... Welding part, 14... Clad,
21... Probe section, 22.23... Drive section, 24.
... Connection pipe, 25 ... Connection part, 26 ... Rubber ring, 27 ... Liquid level, 28 ... Control device, 29 ... Display device, 30 ... Pump, 31 ... Water 4111.3
2...Compressor, 33...Cable, 34...
・Probe insertion mechanism, 35...screw, 36...'jJ
/ l1J 12th 3rd country 7j+ th'! iF S Figgi Fig. 1 F 7Z ￥ δ Fig. cI Fig.'lF/θ Fig. 1/Continued from Fig. 1 page ■ Applicant: Chubu Electric Power Co., Ltd., Higashishinmachi Ichiban, Higashi-ku, Nagoya @ Applicant: Chugoku Electric Power Co., Ltd. Company 4-33 Komachi, Naka-ku, Hiroshima City @Applicant Japan Atomic Power Co., Ltd. 6-1 Otemachi-chome, Chiyoda-ku, Tokyo Applicant Tokyo Shibaura Electric Co., Ltd. 72 Horikawa-cho, Saiwai-ku, Kawasaki City ■Applicant Applicant: Hitachi, Ltd. 324-5-1 Marunouchi, Chiyoda-ku, Tokyo

Claims (1)

[Claims] 1. An ultrasonic probe that is movable in the axial direction and circumferential direction within the tube to be inspected, and an axial drive that is inserted into the tube and drives the probe in the axial direction. a circumferential driving means inserted into the tube and driving the probe in a circumferential direction;
means for filling liquid only between the ultrasonic probe and the inner surface of the tube; the ultrasonic probe; the axial drive means;
means for inserting a part of the circumferential driving means and the liquid optical fiber means into the tube; and transmitting ultrasonic waves from the ultrasonic probe and receiving and processing reflected waves from the tube to be inspected. An ultrasonic inspection device comprising means for displaying an image of a defect inside the tube. 2. In the device according to claim 1, the circumferential driving means is provided at the distal end in the insertion direction, and 1 the ultrasonic probe is disposed between the axial driving means and the circumferential driving means. An ultrasonic inspection device characterized by: