Laser ultrasonic testing device for reactor pressure vessel head bolts

Abstract

The application discloses a reactor pressure vessel head bolt laser ultrasonic inspection device, which comprises a rack, a guide transmission mechanism, a pair of detection rotating mechanisms, a clamping mechanism, a horizontal overturning mechanism and a detection acting mechanism. The reactor pressure vessel head bolt laser ultrasonic inspection device realizes the clamping, posture adjustment, excitation and reception of ultrasonic signals of the head bolt through the cooperation of the rack, the guide transmission mechanism, the detection rotating mechanism, the clamping mechanism, the horizontal overturning mechanism and the detection acting mechanism. Compared with a traditional detection device, the device has high integration and can realize comprehensive detection of the head bolt, adopts a laser ultrasonic detection mode, does not need to be directly contacted with the surface of the head bolt and avoids damage to the surface of the head bolt. The pair of detection rotating mechanisms are respectively provided with ultrasonic detection probes and pulse lasers, the relative positions and angles of the two can be flexibly adjusted, and the accuracy and flexibility of detection are ensured.

Description

Technical Field

[0001] This invention relates to the field of ultrasonic inspection in nuclear power plants, and more particularly to a laser ultrasonic inspection device for reactor pressure vessel head bolts. Background Technology

[0002] The reactor pressure vessel, also known as the reactor pressure shell, withstands high temperatures, high pressures, and intense neutron radiation in the primary loop system. It houses the reactor core, internal components, and supports the control rod drive mechanism and reactor top structure. It is one of the most critical pieces of equipment in nuclear power plants and nuclear power systems, classified as a Class 1 safety, Class 1 seismic, and Class 1 quality assurance device. Ensuring the stable and healthy operation of this equipment is of paramount importance in nuclear power plant non-destructive testing.

[0003] Reactor pressure vessel head bolts are large fasteners connecting the reactor vessel body and top cover. Operating under high temperature, high pressure, and high radiation environments for extended periods, they are prone to surface damage and creep failure. They are critical load-bearing and vulnerable components of the reactor pressure vessel and are a key focus of pre-service and in-service inspections of nuclear power plants as specified in RSEM standards. Regular non-destructive testing of the surface stress of the head bolts to ensure they meet standard requirements is essential for the safe and reliable operation of the nuclear power plant.

[0004] Currently, common stress detection methods include blind hole method, X-ray diffraction, neutron diffraction, and Barkhausen magnetic measurement. The blind hole method involves drilling a small hole in the surface of the part where residual stress is generated, releasing the stress in the vicinity of the hole and producing corresponding strain. By measuring the strain, the average residual stress along the hole depth can be calculated. However, although the blind hole method has relatively low detection cost, its detection range is small, and its destructive nature severely limits its application in in-situ detection on end caps and bolts. X-ray diffraction is a highly accurate method for measuring residual stress and is currently the most mature technology for measuring residual stress. However, this method can only detect stress on the shallow surface of the part and requires electrolytic layer-by-layer polishing to detect residual stress at different depths below the surface. Therefore, its detection efficiency is low, and the required X-ray diffractometer is expensive. Neutron diffraction utilizes the diffraction phenomenon produced by the interaction of neutrons with atoms in a crystal to infer the stress distribution in the material. However, its sample preparation process is complex, and the instrument cost is high. The Barkhausen magnetic method has advantages such as being non-destructive and having a fast measurement speed, but it cannot measure large residual stresses and the material to be measured must be a ferromagnetic material.

[0005] Furthermore, existing testing devices suffer from problems such as poor clamping and positioning stability of bolts, insufficient degrees of freedom of movement of the testing mechanism, and difficulty in achieving omnidirectional testing of the entire bolt surface when inspecting reactor pressure vessel head bolts. This results in low testing coverage and difficulty in guaranteeing testing accuracy. Therefore, developing a laser ultrasonic testing device that can achieve stable clamping of head bolts, multi-degree-of-freedom adjustment of the testing mechanism, and high testing accuracy is of significant practical importance. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a laser ultrasonic inspection device for reactor pressure vessel head bolts.

[0007] The technical solution adopted by the present invention to solve its technical problem is: to construct a laser ultrasonic inspection device for reactor pressure vessel head bolts, which includes a frame, a guide transmission mechanism, a pair of detection rotation mechanisms, a clamping mechanism, a horizontal flipping mechanism, and a detection action mechanism; The clamping mechanism is used to clamp the end cap bolts; The horizontal flipping mechanism is connected to the clamping mechanism and is used to perform horizontal rotation and vertical flipping of the clamping mechanism; The guide transmission mechanism is mounted on the frame, and the horizontal flipping mechanism and the pair of detection rotating mechanisms are all connected to the guide transmission mechanism. The guide transmission mechanism is used to drive the horizontal flipping mechanism and the pair of detection rotating mechanisms to move. The detection mechanism includes an ultrasonic detection probe and a pulsed laser. The pulsed laser excites an ultrasonic signal on the surface of the end cap bolt. The ultrasonic detection probe receives the ultrasonic signal. The ultrasonic detection probe is mounted on one of the detection rotation mechanisms, and the pulsed laser is mounted on the other detection rotation mechanism. The detection rotation mechanism is used to drive the detection mechanism to rotate.

[0008] In some embodiments, the guide transmission mechanism includes a bottom longitudinal sliding module, a connecting mounting plate, a top transverse sliding module, a top vertical sliding module, and a guide plate; The bottom longitudinal sliding module is installed at the bottom of the frame and is arranged along the longitudinal direction of the frame. The connecting mounting plate is installed on the bottom longitudinal sliding module and can move along the longitudinal direction of the frame. The top horizontal sliding module is installed on the top of the frame and is arranged along the horizontal direction of the frame; the top vertical sliding module is movably installed on the top horizontal sliding module and can move along the horizontal direction of the frame. The guide plate is mounted on the top vertical sliding module and can move along the vertical direction of the frame.

[0009] In some embodiments, the bottom longitudinal sliding module, the top transverse sliding module, and the top vertical sliding module all employ a motor lead screw structure.

[0010] In some embodiments, the detection rotation mechanism includes a rotating base, a first detection rotation driver, a first drive connecting block, a second drive connecting block, a detection mounting base, a second detection rotation driver, and a connecting fork; The rotating base is mounted on the guide plate. The first detection rotation driver is mounted on the rotating base and its output end is connected to the first drive connecting block. The second drive connecting block is connected to the first drive connecting block and is connected to the detection mounting base via a first detection rotation shaft. The detection action mechanism is mounted on the detection mounting base. The second detection rotation driver is mounted on the rotating base and its output end is connected to the connecting fork. The connecting fork is connected to the detection mounting base via a second detection rotation shaft. The central axis of the first detection rotation shaft is perpendicular to the central axis of the second detection rotation shaft. The first detection rotary driver is used to drive the detection mounting base to rotate along the central axis of the second detection rotary shaft, and the second detection rotary driver is used to drive the detection mounting base to rotate along the central axis of the first detection rotary shaft.

[0011] In some embodiments, both the first detection rotary driver and the second detection rotary driver are servo motors.

[0012] In some embodiments, the clamping mechanism includes a clamping base plate and a pair of clamping assemblies mounted on the clamping base plate, the clamping assemblies including a connecting column, a pressure plate, a pressure rod, an adjusting member, and a clamping positioning seat; The connecting support is mounted on the base plate of the fixture, the pressure plate is hinged to the connecting support, the pressure rod is mounted on the base plate of the fixture and is correspondingly arranged with the pressure plate, the clamping positioning seat is mounted on the base plate of the fixture and is located below the pressure plate, the clamping positioning seat is provided with a positioning groove for positioning the end cap bolt, and the adjusting member is mounted on the pressure rod and is used to adjust the clamping degree of the pressure plate on the end cap bolt.

[0013] In some embodiments, the horizontal flipping mechanism includes a flipping base plate, a horizontal rotation driver, a horizontal rotation connecting seat, a flipping driver, and a flipping connecting seat; The flip base plate is mounted on the connecting mounting plate, the horizontal rotation driver is mounted on the flip base plate and the output end of the horizontal rotation driver is connected to the horizontal rotation connecting seat. The horizontal rotation driver is used to drive the horizontal rotation connecting seat to rotate. The flip driver is mounted on the flip connecting seat and the output end of the flip driver is fixedly connected to the horizontal rotation connecting seat. The flip driver is used to drive the flip connecting seat to flip. The clamp base plate is mounted on the flip connecting seat.

[0014] In some embodiments, the number of the flip drives is a pair, and the pair of flip drives are separately installed on both sides of the flip connector.

[0015] In some embodiments, the detection mechanism further includes a laser interferometer.

[0016] In some embodiments, the laser ultrasonic testing device for reactor pressure vessel head bolts further includes a control mechanism, which includes a signal processor and a computer communicatively connected to the signal processor.

[0017] The present invention offers the following advantages: This laser ultrasonic testing device for reactor pressure vessel head bolts achieves the clamping, attitude adjustment, and ultrasonic signal excitation and reception of the head bolts through the coordinated operation of a frame, guiding transmission mechanism, detection rotation mechanism, clamping mechanism, horizontal flipping mechanism, and detection action mechanism. Compared to traditional testing devices, this device boasts high integration, enabling comprehensive testing of the head bolts. Employing laser ultrasonic testing, it avoids direct contact with the head bolt surface, preventing damage. A pair of detection rotation mechanisms, each housing an ultrasonic testing probe and a pulsed laser, allows for flexible adjustment of their relative position and angle, ensuring both accuracy and flexibility in testing. This laser ultrasonic testing device for reactor pressure vessel head bolts effectively solves the problem of ultrasonic testing of surface stress in head bolts. It features a high degree of automation, enabling both on-site and remote control, low radiation dose to personnel, a simple structure, ease of manufacture, and low cost. Attached Figure Description

[0018] To more clearly illustrate the technical solution of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the laser ultrasonic testing device for reactor pressure vessel head bolts in some embodiments of the present invention; Figure 2This is a schematic diagram of the detection rotation mechanism in some embodiments of the present invention; Figure 3 This is a schematic diagram of the clamping mechanism in some embodiments of the present invention; Figure 4 This is a schematic diagram of the structure of the horizontal flipping mechanism in some embodiments of the present invention. Detailed Implementation

[0019] To provide a clearer understanding of the technical features, objectives, and effects of this invention, specific embodiments are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "front," "rear," "upper," "lower," "left," "right," "longitudinal," "horizontal," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing this technical solution and do not indicate that the device or element referred to must have a specific orientation; therefore, they should not be construed as limitations on this invention.

[0020] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "linking," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0021] Please see Figures 1 to 4This invention relates to a laser ultrasonic testing device for reactor pressure vessel head bolts, as described in some embodiments. The device includes a frame 1, a guide transmission mechanism 2, a pair of detection rotation mechanisms 3, a clamping mechanism 4, a horizontal flipping mechanism 5, and a detection mechanism 6. The clamping mechanism 4 clamps the head bolts. The horizontal flipping mechanism 5 is connected to the clamping mechanism 4 and is used to rotate the clamping mechanism 4 horizontally and vertically. The guide transmission mechanism 2 is mounted on the frame 1, and both the horizontal flipping mechanism 5 and the pair of detection rotation mechanisms 3 are connected to the guide transmission mechanism 2. The guide transmission mechanism 2 drives the horizontal flipping mechanism 5 and the pair of detection rotation mechanisms 3 to move. The detection mechanism 6 includes an ultrasonic detection probe and a pulsed laser. The pulsed laser excites ultrasonic signals on the surface of the head bolts, and the ultrasonic detection probe receives the ultrasonic signals. The ultrasonic detection probe is mounted on one of the detection rotation mechanisms 3, and the pulsed laser is mounted on the other detection rotation mechanism 3. The detection rotation mechanism 3 drives the detection mechanism 6 to rotate.

[0022] This laser ultrasonic testing device for reactor pressure vessel head bolts is mainly used for non-contact ultrasonic testing of internal defects such as cracks, porosity, and inclusions in reactor pressure vessel head bolts. It achieves accurate quality assessment of the head bolts by exciting ultrasonic signals with a laser and receiving and analyzing them, ensuring the safe operation of the reactor pressure vessel. The frame 1 serves as the supporting foundation for the entire device; it is a gantry structure that provides a mounting platform for other mechanisms such as the guide transmission mechanism 2 and the horizontal tilting mechanism 5. The frame 1 is made of high-strength alloy material, possessing sufficient rigidity and stability, effectively preventing deformation of the frame 1 during testing from affecting the testing accuracy.

[0023] The principle of laser-induced ultrasonic signals is as follows: When the laser energy emitted by a pulsed laser is focused onto the surface of a bolt end cap, some energy is transferred to the material itself, manifesting as heat and stress wave energy. Depending on the incident laser energy, either a thermoelastic effect or a thermo-erosive effect will occur. Thermoelastic effect: When the laser energy irradiating the bolt end cap is insufficient to melt its surface, the material absorbs the light energy and undergoes rapid thermal expansion, generating stress waves with polarization parallel to the surface, i.e., ultrasonic shear waves. This mainly excites ultrasonic transverse waves and relatively small longitudinal waves, as well as Rayleigh waves. In this case, the heat absorbed by the surface does not exceed its melting temperature, resulting in a short-term expansion process. The stress waves associated with this expansion are mostly within the elastic range. Thermo-erosive effect: When the incident laser power density is high, the temperature of the bolt end cap surface will rise sharply to the material's melting point, causing a small portion of the surface material to vaporize, forming plasma. A reaction stress perpendicular to the surface then acts on the surface, exciting ultrasonic longitudinal waves with larger amplitudes. Ultrasonic detection probes can receive ultrasonic waves generated by pulsed laser excitation in either contact or non-contact methods. Non-contact receiving methods typically utilize laser beams to detect the propagation of ultrasonic waves. For example, by using equipment such as laser interferometers, minute surface displacements or vibrations can be measured, and the ultrasonic vibration information carried by the optical signal can be demodulated.

[0024] Understandably, this laser ultrasonic testing device for reactor pressure vessel head bolts achieves the clamping, attitude adjustment, and ultrasonic signal excitation and reception of the head bolts through the coordinated operation of the frame 1, guide transmission mechanism 2, detection rotation mechanism 3, clamping mechanism 4, horizontal tilting mechanism 5, and detection action mechanism 6. Compared with traditional testing devices, this device has a high degree of integration, enabling comprehensive testing of the head bolts. Employing laser ultrasonic testing, it avoids direct contact with the head bolt surface, preventing damage. A pair of detection rotation mechanisms 3 respectively mount the ultrasonic testing probe and the pulsed laser, allowing flexible adjustment of their relative position and angle to ensure testing accuracy and flexibility. This laser ultrasonic testing device for reactor pressure vessel head bolts effectively solves the problem of ultrasonic testing of surface stress in head bolts. It features a high degree of automation, enabling on-site and remote control, low radiation dose to personnel, simple structure, ease of manufacture, and low cost.

[0025] like Figure 1As shown, the guide transmission mechanism 2 includes a bottom longitudinal sliding module 21, a connecting mounting plate 22, a top transverse sliding module 23, a top vertical sliding module 24, and a guide plate 25. The bottom longitudinal sliding module 21 is installed at the bottom of the frame 1 and is arranged along the longitudinal direction of the frame 1. The connecting mounting plate 22 is installed on the bottom longitudinal sliding module 21 and can move along the longitudinal direction of the frame 1. The top transverse sliding module 23 is installed at the top of the frame 1 and is arranged along the transverse direction of the frame 1. The top vertical sliding module 24 is movably installed on the top transverse sliding module 23 and can move along the transverse direction of the frame 1. The guide plate 25 is installed on the top vertical sliding module 24 and can move along the vertical direction of the frame 1. Through the arrangement of the bottom longitudinal sliding module 21, the top transverse sliding module 23, and the top vertical sliding module 24, precise movement of the detection rotation mechanism 3, the clamping mechanism 4, the horizontal flipping mechanism 5, and the detection action mechanism 6 in three-dimensional space is achieved, covering all detection parts of the end cap bolt and avoiding detection blind spots. The connection between the mounting plate 22 and the guide plate 25 makes the connection between the sliding modules more stable and the motion transmission more reliable. The modular design of the guide transmission mechanism 2 facilitates installation, debugging and maintenance, reducing the maintenance cost of the device.

[0026] Preferably, the bottom longitudinal sliding module 21, the top transverse sliding module 23, and the top vertical sliding module 24 all adopt a motor lead screw structure. The motor lead screw structure has advantages such as high transmission accuracy, smooth operation, fast response speed, and accurate positioning, which can ensure that the guide transmission mechanism 2 drives the detection rotation mechanism 3 to achieve high-precision positioning, thereby improving the accuracy and repeatability of detection. At the same time, the motor lead screw structure has a long service life and high reliability, which can reduce the failure rate of the device and improve the operational stability of the device.

[0027] like Figure 2As shown, the detection rotation mechanism 3 includes a rotating base 31, a first detection rotation driver 32, a first drive connecting block 33, a second drive connecting block 34, a detection mounting base 35, a second detection rotation driver 37, and a connecting fork 38. The rotating base 31 is mounted on the guide plate 25. The first detection rotation driver 32 is mounted on the rotating base 31, and its output end is connected to the first drive connecting block 33. The second drive connecting block 34 is connected to the first drive connecting block 33 and is connected to the detection mounting base 35 via a first detection rotation shaft 36. The detection action mechanism 6 is mounted on the detection mounting base 35. The second detection rotation driver 37 is mounted on the rotating base 31, and its output end is connected to the connecting fork 38. The connecting fork 38 is connected to the detection mounting base 35 via a second detection rotation shaft 39. The central axis of the first detection rotation shaft 36 is perpendicular to the central axis of the second detection rotation shaft 39. The first detection rotary driver 32 is used to drive the detection mounting base 35 to rotate along the central axis of the second detection rotary shaft 39, and the second detection rotary driver 37 is used to drive the detection mounting base 35 to rotate along the central axis of the first detection rotary shaft 36.

[0028] Specifically, the first drive connecting block 33 and the second drive connecting block 34 are fixedly connected by bolts. Through the cooperation of the first detection rotary driver 32, the first drive connecting block 33, the second drive connecting block 34, the first detection rotary shaft 36, the second detection rotary driver 37, and the connecting fork 38, the detection mounting base 35 and the detection action mechanism 6 are rotated around the first detection rotary shaft 36 and the second detection rotary shaft 39. The angle between the detection action mechanism 6 and the surface of the end cap bolt can be adjusted to ensure that the laser is incident at the optimal angle and the ultrasonic signal is effectively received. The rotating base 31 is connected to the guide plate 25, which is stable and facilitates the adjustment of the overall position of the detection rotary mechanism 3, further improving the flexibility of detection. In addition, the first detection rotary shaft 36 and the second detection rotary shaft 39 are set perpendicularly, realizing the rotation of the detection mounting base 35 and the detection action mechanism 6 in two vertical directions, that is, multi-angle adjustment in space. This structure enables the detection action mechanism 6 to adapt to the detection needs of different parts of the end cap bolt, especially complex structural parts such as the threads of the end cap bolt and the connection between the head and the shank, effectively improving the comprehensiveness and applicability of the detection. Both the first detection rotary driver 32 and the second detection rotary driver 37 are preferably servo motors.

[0029] like Figure 3As shown, the clamping mechanism 4 includes a clamping base plate 41 and a pair of clamping assemblies mounted on the clamping base plate 41. Each clamping assembly includes a connecting support 42, a pressure plate 43, a pressure rod 44, an adjusting member 45, and a clamping positioning seat 46. The connecting support 42 is mounted on the clamping base plate 41, the pressure plate 43 is hinged to the connecting support 42, the pressure rod 44 is mounted on the clamping base plate 41 and is correspondingly positioned to the pressure plate 43, and the clamping positioning seat 46 is mounted on the clamping base plate 41 and located below the pressure plate 43. The clamping positioning seat 46 has a positioning groove 461 for positioning the end cap bolts. The adjusting member 45 is mounted on the pressure rod 44 and is used to adjust the clamping tightness of the pressure plate 43 on the end cap bolts. The positioning groove 461 of the clamping positioning seat 46 allows for quick and accurate positioning of the end cap bolts, improving the efficiency of end cap bolt clamping. A pair of symmetrically arranged clamping components can stably clamp the end cap bolts, preventing displacement during testing. The pressure plate 43 is hinged to the connecting support 42, and with the adjusting component 45 on the pressure rod 44, the clamping degree can be flexibly adjusted according to the specifications of the end cap bolts, ensuring clamping stability and preventing damage to the end cap bolts. The clamping mechanism 4 has a simple structure and is easy to operate, reducing the labor intensity of operators. The adjusting component 45 can be a nut, which can be threadedly connected to the pressure rod 44.

[0030] like Figure 4 As shown, the horizontal flipping mechanism 5 includes a flipping base plate 51, a horizontal rotation driver 52, a horizontal rotation connecting seat 53, a flipping driver 54, and a flipping connecting seat 55. The flipping base plate 51 is mounted on the connecting mounting plate 22. The horizontal rotation driver 52 is mounted on the flipping base plate 51, and its output end is connected to the horizontal rotation connecting seat 53. The horizontal rotation driver 52 drives the horizontal rotation connecting seat 53 to rotate. The flipping driver 54 is mounted on the flipping connecting seat 55, and its output end is fixedly connected to the horizontal rotation connecting seat 53. The flipping driver 54 drives the flipping connecting seat 55 to flip. The clamp base plate 41 is mounted on the flipping connecting seat 55. Specifically, the output end of the flipping driver 54 is fixed to the horizontal rotation connecting seat 53. When the flipping driver 54 is driven, its output end remains stationary, and the flipping driver 54 and the flipping connecting seat 55 flip together. The horizontal rotation actuator 52 drives the clamping mechanism 4 and the end cap bolt to rotate horizontally, while the tilting actuator 54 drives the clamping mechanism 4 and the end cap bolt to tilt vertically, realizing the attitude adjustment of the end cap bolt in both horizontal and vertical directions. Through attitude adjustment, any detection part of the end cap bolt can be adjusted to a position convenient for detection, solving the problem of inconvenient detection caused by the fixed attitude of the end cap bolt in traditional devices. The horizontal tilting mechanism 5 works in conjunction with the guide transmission mechanism 2 to further expand the detection range and improve the detection capability of the device.

[0031] There is a pair of flipping actuators 54, which are installed separately on both sides of the flipping connector 55. The dual-side drive method allows the flipping connector 55 and the clamping mechanism 4 to be subjected to more even force during the flipping process, avoiding the instability or component deformation caused by single-side drive. At the same time, the dual-side drive can provide greater flipping power, adapt to the flipping requirements of end cap bolts of different weights and specifications, and improve the load-bearing capacity and operational stability of the device.

[0032] The detection mechanism 6 also includes a laser interferometer, which has extremely high detection sensitivity and accuracy. It can assist in the verification and supplementary analysis of the signals received by the ultrasonic detection probe, effectively improving the accuracy and reliability of ultrasonic signal detection. In particular, the laser interferometer can capture the weak ultrasonic signals generated by tiny defects more clearly, thereby improving the device's ability to identify tiny defects and further ensuring the detection quality of the end cap bolts.

[0033] The laser ultrasonic testing device for reactor pressure vessel head bolts also includes a control mechanism, which comprises a signal processor and a computer connected to the signal processor. The signal processor professionally processes the detection signals, removing noise interference and extracting valid signals. The computer analyzes the processed signals using specialized software, enabling automatic identification, location, and quantification of defects, thus improving detection efficiency and the objectivity of results. Simultaneously, the computer centrally controls each drive mechanism, achieving automated testing, reducing manual operation, minimizing human error, and improving consistency and repeatability. Furthermore, the computer can store detection data and generate test reports, facilitating the traceability and management of test results.

[0034] The working process of this embodiment is as follows: First, the end bolt to be tested is placed in the positioning groove 461 of the clamping positioning seat 46 of the clamping mechanism 4, and the end bolt is pressed and fixed by adjusting the pressure plate 43 through the adjusting component 45. Then, the detection program is started by the computer, and the control mechanism controls the bottom longitudinal sliding module 21 to drive the horizontal flipping mechanism 5 and the clamping mechanism 4 to move longitudinally, so that the end bolt moves to the detection area. At the same time, the top transverse sliding module 23 and the top vertical sliding module 24 are controlled to drive the guide plate 25 and the detection rotation mechanism 3 to move laterally and vertically, so that the ultrasonic detection probe and pulse laser of the detection action mechanism 6 are aligned with the initial detection surface of the end bolt. During the detection process, the control mechanism can control the horizontal rotation driver 52 to drive the clamping mechanism 4 to rotate horizontally, and control the flipping driver 54 to drive the clamping mechanism 4 to flip vertically, adjusting the posture of the end bolt. At the same time, the first detection rotation driver 32 and the second detection rotation driver 37 are controlled to drive the detection mounting seat 35 to rotate, adjusting the detection angle of the ultrasonic detection probe and the pulse laser. A pulsed laser excites ultrasonic signals on the surface of the end cap bolt. An ultrasonic testing probe receives these signals and transmits them to a signal processor. A laser interferometer performs auxiliary verification and analysis on the signals before simultaneously transmitting them to the signal processor. The signal processor then transmits the signals to a computer, which analyzes the signals to determine if the end cap bolt has any defects. After the inspection is complete, the computer automatically generates an inspection report, the control mechanism resets all components, and the inspected end cap bolt is removed.

[0035] The laser ultrasonic testing device for reactor pressure vessel head bolts of the present invention achieves stable clamping of the head bolts through a clamping mechanism 4, horizontal rotation and vertical flipping of the head bolts through a horizontal flipping mechanism 5, precise positioning of the clamping mechanism 4 and the detection rotation mechanism 3 in the longitudinal, lateral, and vertical directions through a guide transmission mechanism 2, and multi-angle adjustment of the detection action mechanism 6 through the detection rotation mechanism 3. This enables omnidirectional laser ultrasonic testing of the entire surface of the head bolts, improving detection coverage and accuracy. Simultaneously, the control mechanism automates the testing process and the processing of detection data, improving testing efficiency and intelligence.

[0036] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A laser ultrasonic testing device for reactor pressure vessel head bolts, characterized in that, It includes a frame (1), a guide transmission mechanism (2), a pair of detection rotation mechanisms (3), a clamping mechanism (4), a horizontal flipping mechanism (5), and a detection action mechanism (6); The clamping mechanism (4) is used to clamp the head bolts; The horizontal flipping mechanism (5) is connected to the clamping mechanism (4) and is used to perform horizontal rotation and vertical flipping of the clamping mechanism (4); The guide transmission mechanism (2) is mounted on the frame (1). The horizontal flipping mechanism (5) and the pair of detection rotating mechanisms (3) are all connected to the guide transmission mechanism (2). The guide transmission mechanism (2) is used to drive the horizontal flipping mechanism (5) and the pair of detection rotating mechanisms (3) to move. The detection mechanism (6) includes an ultrasonic detection probe and a pulsed laser. The pulsed laser excites an ultrasonic signal on the surface of the end cap bolt. The ultrasonic detection probe receives the ultrasonic signal. The ultrasonic detection probe is mounted on one of the detection rotation mechanisms (3), and the pulsed laser is mounted on the other detection rotation mechanism (3). The detection rotation mechanism (3) is used to drive the detection mechanism (6) to rotate. The detection rotation mechanism (3) includes a rotating base (31), a first detection rotation driver (32), a first drive connecting block (33), a second drive connecting block (34), a detection mounting base (35), a second detection rotation driver (37), and a connecting fork (38); The first detection rotary driver (32) is mounted on the rotating base (31) and the output end of the first detection rotary driver (32) is connected to the first drive connecting block (33). The second drive connecting block (34) is connected to the first drive connecting block (33) and the second drive connecting block (34) is connected to the detection mounting base (35) through the first detection rotary shaft (36). The detection action mechanism (6) is mounted on the detection mounting base (35). The second detection rotary driver (37) is mounted on the rotating base (31) and the output end of the second detection rotary driver (37) is connected to the connecting fork (38). The connecting fork (38) is connected to the detection mounting base (35) through the second detection rotary shaft (39). The central axis of the first detection rotary shaft (36) is perpendicular to the central axis of the second detection rotary shaft (39). The first detection rotary driver (32) is used to drive the detection mounting base (35) to rotate along the central axis of the second detection rotary shaft (39), and the second detection rotary driver (37) is used to drive the detection mounting base (35) to rotate along the central axis of the first detection rotary shaft (36).

2. The laser ultrasonic testing device for reactor pressure vessel head bolts according to claim 1, characterized in that, The guide transmission mechanism (2) includes a bottom longitudinal sliding module (21), a connecting mounting plate (22), a top transverse sliding module (23), a top vertical sliding module (24), and a guide plate (25); The rotating base (31) is mounted on the guide plate (25); The bottom longitudinal sliding module (21) is installed at the bottom of the frame (1) and is arranged along the longitudinal direction of the frame (1). The connecting mounting plate (22) is installed on the bottom longitudinal sliding module (21) and can move along the longitudinal direction of the frame (1). The top horizontal sliding module (23) is installed on the top of the frame (1) and is arranged in the horizontal direction of the frame (1). The top vertical sliding module (24) is movably installed on the top horizontal sliding module (23) and can move in the horizontal direction of the frame (1). The guide plate (25) is mounted on the top vertical sliding module (24) and can move along the vertical direction of the frame (1).

3. The laser ultrasonic testing device for reactor pressure vessel head bolts according to claim 2, characterized in that, The bottom longitudinal sliding module (21), the top transverse sliding module (23), and the top vertical sliding module (24) all adopt a motor lead screw structure.

4. The laser ultrasonic testing device for reactor pressure vessel head bolts according to claim 3, characterized in that, Both the first detection rotary driver (32) and the second detection rotary driver (37) are servo motors.

5. The laser ultrasonic testing device for reactor pressure vessel head bolts according to claim 2, characterized in that, The clamping mechanism (4) includes a clamping base plate (41) and a pair of clamping components mounted on the clamping base plate (41). The clamping components include a connecting column (42), a pressure plate (43), a pressure rod (44), an adjusting member (45), and a clamping positioning seat (46). The connecting support (42) is mounted on the fixture base plate (41), the pressure plate (43) is hinged to the connecting support (42), the pressure rod (44) is mounted on the fixture base plate (41) and the pressure rod (44) is correspondingly arranged with the pressure plate (43), the clamping positioning seat (46) is mounted on the fixture base plate (41) and located below the pressure plate (43), the clamping positioning seat (46) is provided with a positioning groove (461) for positioning the end cap bolt, and the adjusting member (45) is mounted on the pressure rod (44) and is used to adjust the clamping degree of the pressure plate (43) on the end cap bolt.

6. The laser ultrasonic testing device for reactor pressure vessel head bolts according to claim 5, characterized in that, The horizontal flipping mechanism (5) includes a flipping base plate (51), a horizontal rotation driver (52), a horizontal rotation connecting seat (53), a flipping driver (54), and a flipping connecting seat (55). The flip base plate (51) is mounted on the connecting mounting plate (22). The horizontal rotation driver (52) is mounted on the flip base plate (51) and the output end of the horizontal rotation driver (52) is connected to the horizontal rotation connecting seat (53). The horizontal rotation driver (52) is used to drive the horizontal rotation connecting seat (53) to rotate. The flip driver (54) is mounted on the flip connecting seat (55) and the output end of the flip driver (54) is fixedly connected to the horizontal rotation connecting seat (53). The flip driver (54) is used to drive the flip connecting seat (55) to flip. The clamp base plate (41) is mounted on the flip connecting seat (55).

7. The laser ultrasonic testing device for reactor pressure vessel head bolts according to claim 6, characterized in that, The number of the flip drives (54) is one pair, and the pair of flip drives (54) are installed separately on both sides of the flip connector (55).

8. The laser ultrasonic testing device for reactor pressure vessel head bolts according to claim 1, characterized in that, The detection mechanism (6) also includes a laser interferometer.

9. The laser ultrasonic testing device for reactor pressure vessel head bolts according to claim 1, characterized in that, The laser ultrasonic testing device for reactor pressure vessel head bolts also includes a control mechanism, which includes a signal processor and a computer communicatively connected to the signal processor.

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