Ultrasonic inspection device for guide holes of control rod guide tubes

Abstract

The present invention provides an ultrasonic inspection device for a guide hole of a control rod guide tube, comprising an opening and closing assembly connection block, a probe opening and closing fixed seat, a probe opening and closing pull rod, a probe opening and closing upper hinge rod and an ultrasonic inspection probe assembly, wherein the opening and closing assembly connection block is fixedly connected to the probe opening and closing fixed seat as a whole and has a cavity, the probe opening and closing pull rod is passed through the cavity, the probe opening and closing upper hinge rod is hinged to the side wall of the probe opening and closing fixed seat, the upper hinge rod pressure end of the probe opening and closing upper hinge rod extends into the probe opening and closing fixed seat, the upper hinge rod opening and closing end of the probe opening and closing upper hinge rod extends out of the probe opening and closing fixed seat, an ultrasonic inspection probe assembly is installed on the upper hinge rod opening and closing end, and the probe opening and closing pull rod is driven to move axially to rotate the probe opening and closing upper hinge rod. The ultrasonic inspection device for the guide hole of a control rod guide tube provided by the present invention can fully cover the guide hole on the inspection guide plate.

Description

Technical Field

[0001] The invention relates to the technical field of nondestructive testing of guide clamp holes in a control rod guide tube of a nuclear power plant, and in particular to an ultrasonic testing device for guide clamp holes in a control rod guide tube. Background Art

[0002] The reactor pressure vessel internals of a nuclear power plant is one of the important equipment in the reactor body structure. It is installed in the reactor pressure vessel and is combined with the reactor pressure vessel, control rod drive mechanism, fuel assembly and related components to realize the reactor function. The guide cylinder assembly is an important part of the internal components. Usually, an upper internal component contains dozens of guide cylinder assemblies, which guide and center the control rod assembly in the up and down movement of the stack. It is mainly composed of an upper guide cylinder assembly and a lower guide cylinder assembly. The bottom of the upper guide cylinder assembly and the top of the lower guide cylinder assembly are fixed on the upper support plate assembly and connected together by flanges. The lower guide cylinder assembly is restricted to the upper plate of the core by two positioning pins at the bottom to achieve positioning and support. There are 9 guide plates distributed inside the guide cylinder assembly, which are used for positioning and guiding the control rod bundle assembly when the rods are dropped. A φ58.65 circular hole is opened in the center of the top of the control rod guide cylinder assembly for the lifting and lowering movement of the grabbing mechanism, and the bottom continuous section is a regular opening and a slide groove combination structure.

[0003] The guide plate is used to position and guide the control rod and provide support to prevent the control rod from excessive deformation due to water flow vibration. It has 24 φ10.725mm circular holes and a central φ61mm circular hole according to the control rod structure.

[0004] Affected by multiple factors such as the frequent up and down movement of control rods during reactor operation and micro-seismicity caused by high-speed water flow, the guide clamping holes of the control rod guide tubes that have been running for a certain number of cycles are generally worn. This wear may lead to the risk of control rod jamming, thus affecting the safe operation of the nuclear power plant. Therefore, after a certain period of operation of the nuclear power plant, a special control rod guide tube guide clamping hole ultrasonic inspection device is usually used to measure the inner surface diameter of each guide clamping hole of the 9-layer guide plate, so as to obtain the wear amount of the inner surface, and replace the guide tube with excessive wear according to the measurement results.

[0005] During the ultrasonic inspection of the guide clamp holes, each inspection probe can only enter the guide tube assembly from the φ58.65mm circular hole at the center of the top of the guide tube assembly, and the radial distribution sizes of the 24 guide clamp holes are all greater than 58.65mm. Therefore, it is necessary to design an ultrasonic inspection device for the guide clamp holes of the control rod guide tube. Summary of the invention

[0006] The object of the present invention is to overcome the defects described in the prior art, thereby providing an ultrasonic inspection device for guide holes of a control rod guide tube. When the ultrasonic inspection device for guide holes of a control rod guide tube is used to perform ultrasonic inspection on the guide holes of the control rod guide tube, each inspection probe can pass through the small-sized central circular hole at the top end of the guide tube assembly and measure the inner surface dimensions of the 24 guide holes.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A control rod guide tube guide clamping ultrasonic inspection device comprises an opening and closing assembly connecting block, a probe opening and closing fixing seat, a probe opening and closing pull rod, a probe opening and closing upper hinge rod and an ultrasonic inspection probe assembly, wherein the opening and closing assembly connecting block is fixedly connected to the probe opening and closing fixing seat as a whole and has a cavity, the probe opening and closing pull rod is passed through the cavity, the probe opening and closing upper hinge rod is hinged to the side wall of the probe opening and closing fixing seat, the upper hinge rod pressure end of the probe opening and closing upper hinge rod extends into the probe opening and closing fixing seat, the upper hinge rod opening and closing end of the probe opening and closing upper hinge rod extends out of the probe opening and closing fixing seat, the ultrasonic inspection probe assembly is installed on the upper hinge rod opening and closing end, and the probe opening and closing pull rod is driven to move axially to rotate the probe opening and closing upper hinge rod.

[0009] As an implementable manner, a rotatable probe opening and closing lower hinge rod is further provided on the probe opening and closing fixing seat, and the probe opening and closing lower hinge rod is hinged to the ultrasonic inspection probe assembly.

[0010] As an implementable manner, two probe opening and closing limit blocks are arranged at intervals on the probe opening and closing pull rod, and the two probe opening and closing limit blocks are respectively located on both sides of the pressure end of the upper hinge rod.

[0011] As an implementable manner, a probe opening and closing elastic top block is installed on one side of the probe opening and closing limit block facing the pressure end of the upper hinge rod.

[0012] As an implementable manner, the probe opening and closing rod is connected to a probe opening and closing cylinder, and the probe opening and closing cylinder drives the probe opening and closing rod to move axially.

[0013] As an implementable method, the ultrasonic inspection probe assembly includes an ultrasonic inspection probe bracket, on which a coaxial ultrasonic immersion probe, an ultrasonic signal reflector and a reflector rotation drive motor are provided. The ultrasonic signal reflector is fixedly mounted on the reflector rotation drive motor and faces the ultrasonic immersion probe.

[0014] As an implementable manner, a dynamic sealing ring is provided in the hole of the ultrasonic inspection probe bracket, and the inner wall of the dynamic sealing ring is in contact with the ultrasonic signal reflector.

[0015] As an implementable manner, a static sealing ring is provided at the lower end of the cavity of the ultrasonic inspection probe holder, the outer wall of the static sealing ring is in contact with the inner wall of the cavity, and a circular hole is opened in the center of the static sealing ring.

[0016] As an implementable method, a lower centering seat is connected below the probe opening and closing fixing seat, a square groove is opened on the lower centering seat, a supporting tile is arranged in the square groove, one end of the supporting tile is connected to the lower centering seat, and the other end is connected to the lower centering slider.

[0017] As an implementable manner, the lower centering sliding block is connected to the upper end of the lower centering cylinder seat, and the lower end of the lower centering cylinder seat is connected to the lower centering cylinder.

[0018] Compared with the prior art, the control rod guide tube guide clamp hole ultrasonic inspection device provided by the present invention has the following beneficial effects:

[0019] After the six ultrasonic inspection probes are folded, they can smoothly pass through the small-sized central circular hole at the top of the guide cylinder to be inspected; after the six ultrasonic inspection probes are opened, they can be rotated in a circle to achieve full coverage of the inspection of the 24 guide holes on the guide plate.

[0020] The ultrasonic inspection probe assembly reflects the ultrasonic signal of the water immersion ultrasonic probe from the vertical direction to the horizontal direction through the ultrasonic signal reflector, thereby realizing a 360-degree full-range ultrasonic inspection of the inner surface of the guide card hole in the narrow guide card hole.

[0021] After the four supporting tiles are folded through the lower supporting mechanism, they can smoothly pass through the small-sized central circular hole at the top of the guide tube to be inspected. After opening, the supporting tiles can be supported in the central circular hole of the lower guide plate, thereby ensuring that the inspection equipment and the inspection probe are in a stable state during ultrasonic inspection, thereby improving the inspection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A schematic structural diagram of a control rod guide tube guide clamp hole ultrasonic inspection device provided by an embodiment of the present invention;

[0024] Figure 2 A cross-sectional view along the AA plane of the ultrasonic inspection device for the guide clamp hole of the control rod guide tube provided by an embodiment of the present invention;

[0025] Figure 3 for Figure 2 The enlarged view of point B;

[0026] Figure 4 A schematic diagram of the structure of the hinge rod on the probe provided by an embodiment of the present invention;

[0027] Figure 5 A schematic diagram of the structure of the probe lower hinge rod provided by an embodiment of the present invention;

[0028] Figure 6 A schematic diagram of the structure of an ultrasonic inspection probe assembly provided by an embodiment of the present invention;

[0029] Figure 7 A cross-sectional view of an ultrasonic inspection probe assembly provided by an embodiment of the present invention along the DD plane;

[0030] Figure 8 A front view of a support tile provided by an embodiment of the present invention;

[0031] Fig. 9 A top view of a support tile provided by an embodiment of the present invention;

[0032] Fig.10 A side view of a support tile provided by an embodiment of the present invention;

[0033] Fig.11 The embodiment of the present invention provides Figure 2 Enlarged view of point C;

[0034] Fig.12 A schematic diagram of a retracted state of a guide clamp hole ultrasonic inspection device for a control rod guide tube provided by an embodiment of the present invention when the ultrasonic inspection device enters the guide tube;

[0035] Fig.13 This is a schematic diagram of the open state of the control rod guide tube guide clamp hole ultrasonic inspection device provided by an embodiment of the present invention when entering the guide tube.

[0036] Description of reference numerals:

[0037] 1. Opening and closing assembly connection block; 2. Probe opening and closing fixing seat; 3. Probe opening and closing cylinder; 4. Probe opening and closing pull rod; 5. Probe opening and closing limit block; 6. Probe opening and closing elastic top block; 7. Probe opening and closing upper hinge rod; 8. Probe opening and closing lower hinge rod; 9. Ultrasonic inspection probe assembly; 10. Lower centering seat; 11. Support tile; 12. Lower centering slider; 13. Lower centering cylinder seat; 14. Lower centering pull rod; 15. Lower centering cylinder; 16. Upper hinge rod fulcrum; 17. Upper hinge rod rivet point; 18. Upper hinge rod pressure end; 19. Upper hinge rod opening and closing end; 20. Lower hinge rod fulcrum; 21. Lower hinge rod rivet point; 22. Ultrasonic inspection probe bracket; 23. Ultrasonic immersion probe; 24. Ultrasonic signal reflector; 25. Dynamic sealing ring; 26. Reflector rotation drive motor; 27. Static sealing ring; 28. Support opening and closing slide. DETAILED DESCRIPTION

[0038] Although the control rod guide tube guide hole ultrasonic inspection device of the present invention can be implemented in many different ways, the exemplary embodiments will be described in detail herein in conjunction with the accompanying drawings. It is understood that the description herein should be considered as an example of the structure of the control rod guide tube guide hole ultrasonic inspection device, and is not intended to limit the protection scope of the present invention to the exemplary embodiments. Therefore, in essence, the drawings and the description of the specific embodiments should be considered to be used to illustrate rather than limit the present invention.

[0039] In the description of the present invention, it should be noted that the terms "up", "down", "left", "right", "inside", "outside", "horizontal", "vertical", etc. used in this document to indicate directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0040] The following is further explained in detail through specific implementation methods.

[0041] like Figures 1 to 3As shown, the present invention provides an ultrasonic inspection device for guide holes of control rod guide tubes, which is used to measure the dimensions of the inner surface of each guide hole, and to remotely control the retraction of six inspection probes when they pass through the central circular hole at the top of the guide tube, and to remotely control the opening of the six inspection probes when the inspection is carried out. The ultrasonic inspection device for guide holes of control rod guide tubes comprises an opening and closing assembly connection block 1, a probe opening and closing fixing seat 2, a probe opening and closing pull rod 4, a probe opening and closing upper hinge rod 7, and an ultrasonic inspection probe assembly 9. The opening and closing assembly connection block 1 and the probe opening and closing fixing seat 2 are fixedly connected as a whole, and they have a cavity inside. The probe opening and closing pull rod 4 is slidably arranged in the cavity. The probe opening and closing upper hinge rod 7 is hinged in the hole of the side wall of the probe opening and closing fixing seat 2, and the upper hinge rod pressure end 18 of the probe opening and closing upper hinge rod 7 extends into the internal cavity of the probe opening and closing fixing seat 2, and the upper hinge rod opening and closing end 19 of the probe opening and closing upper hinge rod 7 extends to the outside of the probe opening and closing fixing seat 2, and the ultrasonic inspection probe assembly 9 is installed on the upper hinge rod opening and closing end 19. The probe opening and closing pull rod 4 is driven to move axially, so that the probe opening and closing upper hinge rod 7 can rotate, thereby causing the ultrasonic inspection probe assembly 9 to rotate.

[0042] The probe opening and closing fixing seat 2 is a fixed frame for six ultrasonic inspection probe assemblies 9, and the six ultrasonic inspection probe assemblies 9 are installed on the upper and lower end surfaces of the fixed frame through the probe opening and closing upper hinge rod 7, the probe opening and closing lower hinge rod 8 and its pin shaft.

[0043] The probe opening and closing cylinder 3 realizes the opening and closing of the ultrasonic inspection probe assembly 9 by means of pneumatic control. A double-acting cylinder is used, which is installed on the upper end of the opening and closing assembly connection block 1 through the cylinder's own external thread, and one end of the piston rod is connected to the probe opening and closing rod 4. Under the action of the probe opening and closing cylinder 3, the probe opening and closing rod 4 can realize relative movement in the central cavity of the opening and closing assembly connection block 1 and the probe opening and closing fixing seat 2.

[0044] like Figure 3 As shown, two probe opening and closing limit blocks 5 are arranged at intervals on the probe opening and closing pull rod 4, and the two probe opening and closing limit blocks 5 are respectively located on both sides of the upper hinge rod pressure end 18. The probe opening and closing limit block 5 is made of hard material and is a disc-shaped structure. It is fixed to the probe opening and closing pull rod 4 by pins or bolts, and moves synchronously with the probe opening and closing pull rod 4 under the action of the probe opening and closing cylinder 3.

[0045] like Figure 3 As shown, a probe opening and closing elastic top block 6 is installed on the side of the probe opening and closing limit block 5 facing the upper hinge rod pressure end 18 (the side close to the upper hinge rod pressure end 18). The probe opening and closing elastic top block 6 is made of elastic material and is also a disc-shaped structure. It is installed on the probe opening and closing limit block 5 by bolts, and moves with the probe opening and closing pull rod 4 together with the probe opening and closing limit block 5.

[0046] like Figure 4As shown, the probe opening and closing upper hinge rod 7 is a thin connecting rod, and its thickness is less than 3mm to adapt to the slots between the guide holes on the guide plate. The probe opening and closing upper hinge rod 7 has two hinge holes, namely the upper hinge rod fulcrum 16 and the upper hinge rod riveting point 17, and the upper hinge rod fulcrum 16 is used as the dividing point to divide it into an upper hinge rod pressure end 18 and an upper hinge rod opening and closing end 19.

[0047] The upper hinge rod fulcrum 16 is installed on the probe opening and closing fixing seat 2 through a pin, and the upper hinge rod riveting point 17 is connected to the ultrasonic inspection probe assembly 9 through a rivet. The probe opening and closing cylinder 3 drives the probe opening and closing pull rod 4, the probe opening and closing limit block 5, and the probe opening and closing elastic top block 6 to move, and then the probe opening and closing elastic top block 6 applies pressure to the upper hinge rod pressure end 18, driving the probe opening and closing upper hinge rod 7 to rotate around the upper hinge rod fulcrum 16, thereby realizing the opening and closing of the ultrasonic inspection probe assembly 9: when the probe opening and closing elastic top block 6 above the probe opening and closing pull rod 4 applies pressure to the upper hinge rod pressure end 18, the six ultrasonic inspection probes are opened synchronously; when the probe opening and closing elastic top block 6 below the probe opening and closing pull rod 4 applies pressure to the upper hinge rod pressure end 18, the six ultrasonic inspection probes are retracted synchronously.

[0048] like Figure 5 As shown, the probe opening and closing lower hinge rod 8 is a thin connecting rod, and like the probe opening and closing upper hinge rod 7, its thickness is also less than 3mm to adapt to the narrow slots between the guide holes on the guide plate. The probe opening and closing lower hinge rod 8 also has two hinged holes, namely the lower hinge rod fulcrum 20 and the lower hinge rod rivet point 21.

[0049] like Figure 3 , Figure 6 and Figure 7 As shown, the ultrasonic inspection probe assembly 9 performs water immersion probe detection on the inner surface of the guide card hole. The ultrasonic inspection probe assembly 9 is connected to the probe opening and closing upper hinge rod 7 and the probe opening and closing lower hinge rod 8 through the upper and lower rivet holes, and it forms a parallel four-bar mechanism together with the probe opening and closing fixing seat 2, the probe opening and closing upper hinge rod 7 and the probe opening and closing lower hinge rod 8. Under the action of the probe opening and closing cylinder 3, the ultrasonic inspection probe assembly 9 opens and closes at an angle that is always parallel to the axis of the guide cylinder to be inspected, so as to ensure that it can smoothly enter each inspected guide card hole and the measurement accuracy of the guide card hole.

[0050] like Figure 7 As shown, the ultrasonic inspection probe assembly 9 is composed of an ultrasonic inspection probe bracket 22, an ultrasonic immersion probe 23, an ultrasonic signal reflector 24, a dynamic sealing ring 25, a reflector rotation drive motor 26, a static sealing ring 27, etc.

[0051] The ultrasonic inspection probe bracket 22 is the mounting base for all parts of the ultrasonic inspection probe assembly 9, and is riveted to the probe opening and closing upper hinge rod 7 and the probe opening and closing lower hinge rod 8 through the upper and lower rivet holes. In order to meet the measurement requirements of the inner surface of the guide card hole, the maximum diameter of the cylindrical part of the ultrasonic inspection probe bracket 22 needs to be smaller than the inner diameter of the guide card hole, that is, less than 10.725mm.

[0052] The ultrasonic immersion probe 23 is a self-made high-frequency ultrasonic immersion probe, which transmits ultrasonic signals and receives reflected ultrasonic signals to transmit to the ultrasonic instrument, thereby obtaining the inner surface size of the guide card hole to be inspected. The ultrasonic immersion probe 23 is installed in the mounting hole on the ultrasonic inspection probe bracket 22 and fixed together by bonding.

[0053] The ultrasonic signal reflector 24 is mounted on the reflector rotation drive motor 26, and the motor output shaft is matched with the center hole of the reflector and fixed together by bonding. The ultrasonic signal reflector 24 reflects the ultrasonic signal from the ultrasonic immersion probe 23 through a 45-degree mirror, and reflects the ultrasonic signal transmitted in the vertical direction into a horizontal direction. The horizontally transmitted ultrasonic signal reaches the inner wall of the guide card hole and is partially reflected. At the same time, the ultrasonic signal reflector receives the reflected horizontally transmitted ultrasonic signal and reflects it into a vertically transmitted ultrasonic signal to the ultrasonic immersion probe 23.

[0054] The dynamic sealing ring 25 is installed in the hole on the ultrasonic inspection probe bracket 22. It adopts an elastic compression structure. Its inner wall fits with the axis of the ultrasonic signal reflector 24, thereby forming a sealing structure to prevent water from entering the sealed cavity of the reflector rotation drive motor 26 during underwater inspection and causing damage to the motor's electrical components.

[0055] The reflector rotation drive motor 26 is also installed in the cavity on the ultrasonic inspection probe bracket 22, and is used to drive the high-speed rotation of the ultrasonic signal reflector 24 when implementing ultrasonic inspection, so as to distribute the ultrasonic signal emitted by the ultrasonic immersion probe 23 to the entire circumferential inner wall of the guide card hole through the ultrasonic signal reflector 24, thereby achieving 360-degree inspection full coverage.

[0056] The static sealing ring 27 is installed at the lower end of the cavity on the ultrasonic inspection probe bracket 22, and adopts an elastic compression structure. Its outer wall fits the inner wall of the cavity, and a circular hole is opened in the center for wiring the reflector rotation drive motor 26.

[0057] like Figures 8 to 11 As shown, the lower centering seat 10 is fixed to the probe opening and closing fixing seat 2 by bolts, and is the mounting base of the lower support mechanism, which is a long rod mechanism, with 4 square grooves on the upper part and an internal thread structure at the lower end center. One end of the 4 support tiles 11 is installed in the 4 square grooves of the lower centering seat 10 by threaded pins, and the internal thread at the lower end center is threadedly connected with the external thread at the upper end of the lower centering rod 14.

[0058] When the support tile 11 is used for inspection, in order to prevent the inspection probe from shaking, it is supported in the central hole of the lower guide plate of the inspected guide plate in the guide cylinder, thereby improving the inspection accuracy. The support tile 11 adopts a long strip design, with two support opening and closing slides 28 on the upper and lower sides, which are respectively connected to the lower centering seat 10 and the lower centering slider 12 through pins, and the support tile 11 is moved radially by the height change of the support opening and closing slides 28, thereby realizing the synchronous opening and closing of the lower support structure.

[0059] The lower centering slider 12 connects the support tile 11 and the lower centering cylinder seat 13, and is a cylindrical structure with four square grooves evenly distributed in the circumferential direction. The support tile 11 is connected to the square groove of the lower centering seat 10 through a pin, and a threaded hole is opened at the bottom, and is connected to the lower centering cylinder seat 13 through bolts.

[0060] The lower centering cylinder seat 13 is a long rod structure with a flange structure designed at the upper end. It is connected to the lower centering slider 12 by bolts. The center of the lower end is an internal thread structure, which is used to fix the cylinder seat of the lower centering cylinder 15. The center is a hole, and the lower centering pull rod 14 passes through it and is connected to the lower centering seat 10.

[0061] The lower centering pull rod 14 is a hollow rod structure, the upper end of which is an external thread, which is threadedly connected with the central internal thread of the lower end of the lower centering seat 10; the lower end of which is an internal thread structure, which is threadedly connected with the external thread of the piston rod of the lower centering cylinder 15.

[0062] The lower centering cylinder 15 is used to drive the opening and closing of the lower support structure. Its piston rod is fixed to the lower centering rod 14 by threaded connection, and its cylinder body is installed on the lower centering cylinder seat 13. When the lower centering cylinder 15 is in action, the piston rod is stationary, and the cylinder body moves under the action of air pressure, thereby causing the lower centering cylinder seat 13 and the lower centering slider 12 to move. The pins on the lower centering slider 12 apply pressure to the support opening and closing slide grooves 28 on the support tiles 11, thereby realizing the synchronous opening and closing of the four support tiles 11: when the cylinder body of the lower centering cylinder 15 moves upward, the cylinder body drives the lower centering cylinder seat 13 and the lower centering slider 12 to move upward through threaded connection, and the pins on the lower centering slider 12 open and close the support on the support tile 11 The slide groove 28 applies upward pressure, and the pin slides radially inward while approaching the height of the supporting opening and closing slide groove 28, so that the four supporting tiles 11 are synchronously retracted; when the cylinder body of the lower centering cylinder 15 moves downward, the cylinder body drives the lower centering cylinder seat 13 and the lower centering slider 12 to move downward through the threaded connection, and the pin on the lower centering slider 12 applies downward pressure to the supporting opening and closing slide groove 28 on the supporting tile 11, and the pin slides radially outward while moving away from the height of the supporting opening and closing slide groove 28, so that the four supporting tiles 11 are synchronously opened.

[0063] When ultrasonic testing is performed on the guide holes of the control rod guide tube, after the ultrasonic testing equipment is installed on the guide tube to be tested, the piston rod of the probe opening and closing cylinder contracts, driving the six probe opening and closing upper hinge rods 7, the ultrasonic testing probe assembly 9, and the probe opening and closing lower hinge rod 8 to retract into the slots on the probe opening and closing fixing seat 2, so that the envelope circle diameter of the six testing probes is less than 58.65mm; the lower centering cylinder body extends, driving the four support tiles 11 to retract synchronously, so that the envelope circle diameter of the four support tiles is also less than 58.65mm, so that the entire control rod guide tube guide hole ultrasonic testing device can smoothly pass through the small-sized circular hole in the center of the top of the guide tube. The retracted state of the control rod guide tube guide hole ultrasonic testing device when entering the guide tube is as shown in the figure. Fig.12 shown.

[0064] When the entire control rod guide tube guide hole ultrasonic inspection device passes through the small-sized circular hole at the center of the top of the guide tube and is ready to perform ultrasonic inspection, the piston rod of the probe opening and closing cylinder extends, and the probe opening and closing pull rod 4 and the probe opening and closing elastic top block 6 press down the pressure end of the upper hinge rod to open the probe opening and closing upper hinge rod 7, and realize the synchronous opening of the six ultrasonic inspection probes to reach the radial position of the guide hole through the parallel four-bar mechanism composed of the probe opening and closing upper hinge rod 7, the ultrasonic inspection probe assembly 9, the probe opening and closing lower hinge rod 8, and the probe opening and closing fixed seat 2, and realize the full coverage of the inspection of the 24 guide holes through circumferential rotation; the cylinder body of the lower centering seat shrinks, driving the four support tiles to open synchronously, and support them to the center circular hole of the lower guide plate, ensuring that the inspection equipment and the inspection probe are in a stable state during the inspection, and improving the detection accuracy of the inner surface of the guide hole. The opening state of the control rod guide tube guide hole ultrasonic inspection device when entering the guide tube is as follows: Fig.13 shown.

[0065] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An ultrasonic inspection device for guide holes of control rod guide tubes, characterized in that: The ultrasonic inspection probe assembly (9) comprises an opening and closing assembly connection block (1), a probe opening and closing fixing seat (2), a probe opening and closing pull rod (4), a probe opening and closing upper hinge rod (7), and an ultrasonic inspection probe assembly (9), wherein the opening and closing assembly connection block (1) is fixedly connected to the probe opening and closing fixing seat (2) as a whole and has a cavity, the probe opening and closing pull rod (4) is arranged in the cavity, the probe opening and closing upper hinge rod (7) is hinged to the side wall of the probe opening and closing fixing seat (2), the upper hinge rod pressure end (18) of the probe opening and closing upper hinge rod (7) extends into the probe opening and closing fixing seat (2), the upper hinge rod opening and closing end (19) of the probe opening and closing upper hinge rod (7) extends out of the probe opening and closing fixing seat (2), the ultrasonic inspection probe assembly (9) is mounted on the upper hinge rod opening and closing end (19), and the probe opening and closing pull rod (4) is driven to move axially to rotate the probe opening and closing upper hinge rod (7); The probe opening and closing fixing seat (2) is also provided with a rotatable probe opening and closing lower hinge rod (8), and the probe opening and closing lower hinge rod (8) is hingedly connected to the ultrasonic inspection probe assembly (9); Two probe opening and closing limit blocks (5) are arranged at intervals on the probe opening and closing pull rod (4), and the two probe opening and closing limit blocks (5) are respectively located on both sides of the pressure end (18) of the upper hinge rod, and a probe opening and closing elastic top block (6) is installed on the side of the probe opening and closing limit block (5) facing the pressure end (18) of the upper hinge rod; the probe opening and closing pull rod (4) is connected to the probe opening and closing cylinder (3), and the probe opening and closing cylinder (3) drives the probe opening and closing pull rod (4) to move axially; The ultrasonic inspection probe assembly (9) comprises an ultrasonic inspection probe bracket (22), on which a coaxial ultrasonic immersion probe (23), an ultrasonic signal reflector (24) and a reflector rotation drive motor (26) are provided, and the ultrasonic signal reflector (24) is fixedly mounted on the reflector rotation drive motor (26) and faces the ultrasonic immersion probe (23); A lower centering seat (10) is connected below the probe opening and closing fixing seat (2); a square groove is formed on the lower centering seat (10); a supporting tile (11) is provided in the square groove; one end of the supporting tile (11) is connected to the lower centering seat (10), and the other end is connected to the lower centering slide block (12); the lower centering slide block (12) is connected to the upper end of the lower centering cylinder seat (13), and the lower end of the lower centering cylinder seat (13) is connected to the lower centering cylinder (15).

2. The control rod guide tube guide hole ultrasonic inspection device according to claim 1, characterized in that: A dynamic sealing ring (25) is provided in the hole of the ultrasonic inspection probe bracket (22), and the inner wall of the dynamic sealing ring (25) is in contact with the ultrasonic signal reflector (24).

3. The control rod guide tube guide hole ultrasonic inspection device according to claim 1, characterized in that: A static sealing ring (27) is provided at the lower end of the cavity of the ultrasonic inspection probe bracket (22); the outer wall of the static sealing ring (27) is in contact with the inner wall of the cavity; and a circular hole is provided at the center of the static sealing ring (27).

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