Expansion coupling clamping device and clamping method
Patent Information
- Application Number
- CN202611164248.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-31
- Publication Date
- 2026-09-15
Smart Images
Figure CN122746945A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of nuclear power plant maintenance technology, and more specifically, relates to an expansion joint clamping device and clamping method. Background Technology
[0002] After undergoing multiple irradiation cycles within the reactor, nuclear fuel assemblies require periodic inspection and maintenance to eliminate defects such as damaged fuel rods and ensure the continued safe operation of the assemblies. During the post-irradiation fuel assembly maintenance process, the disassembly of the connecting screws between the upper tube seat and the guide tube is a crucial step in the maintenance work.
[0003] However, in actual maintenance operations, when repairing the expansion joint failure of the expansion joint of the irradiated nuclear fuel assemblies and guide tubes, a common problem arises during the disassembly and assembly of the screws: the screws and expansion joint rotate synchronously, preventing normal disassembly and assembly. When disassembling the upper tube seat sleeve screws, the expansion joint failure causes the screws and expansion joint to become an integral link, rotating synchronously, preventing the sleeve screws from being properly removed from the sleeve. Therefore, a dedicated device is needed to effectively prevent the screws from rotating along with the tube, to meet the requirements of safe, efficient, and non-destructive disassembly and assembly operations in a radioactive environment. Summary of the Invention
[0004] The purpose of this application is to provide an expansion joint clamping device, which aims to solve the problem in the related art that the nuclear fuel assembly screws and the expansion joint rotate synchronously and cannot be properly disassembled and assembled.
[0005] To achieve the above objectives, the technical solution adopted in this application is as follows: An expansion joint clamping device is provided, comprising: Positioning base, used for installation on the upper tube seat of the nuclear fuel assembly; The adjustment mechanism is mounted on the positioning base; and A clamping mechanism is connected to the output end of the adjustment mechanism, and the clamping mechanism can adjust its clamping posture and align itself with the expansion joint to be repaired under the drive of the adjustment mechanism. The clamping mechanism includes a first driving member, a first gripper and a second gripper. The first driving member is used to drive the first gripper and the second gripper to move relative to each other. The first gripper and the second gripper have a clamping surface adapted to the outer wall of the expansion tube on one side facing each other.
[0006] In some embodiments, the first drive member is connected to the output end of the adjustment mechanism, and the second gripper is connected to the output end of the first drive member. The output end of the first drive member is used to drive the second gripper closer to or further away from the first gripper to clamp or release the expansion joint.
[0007] In some embodiments, the adjustment mechanism includes: The first adjustment component is installed on the upper side of the positioning base; The second adjustment component is connected to the output end of the first adjustment component and moves along the first direction under the drive of the first adjustment component; A third adjustment component is connected to the output terminal of the second adjustment component and moves along a second direction under the drive of the second adjustment component; and An angle adjustment component is connected to the output end of the third adjustment component and moves along a third direction under the drive of the third adjustment component. The clamping mechanism is disposed at the output end of the angle adjustment component, and the angle adjustment component is used to adjust the tilt angle of the clamping mechanism. The first direction, the second direction, and the third direction are arranged perpendicularly to each other.
[0008] In some embodiments, the first regulating component includes: The first support is installed on the positioning base; The first guide post is installed on the first support and extends along the first direction; A first screw extends along a first direction and is rotatably mounted on the first support; The first sliding seat is slidably sleeved on the first guide post and threadedly connected to the first screw; the second adjusting component is installed on the first sliding seat. A first transmission structure, wherein the output end of the first transmission structure is connected to the first screw; and The second driving member has its output end connected to the input end of the first transmission structure. The second driving member is used to provide rotational power and drives the first screw to rotate after being reversed by the first transmission structure. The first sliding seat moves linearly along the first direction under the constraint of the first guide post.
[0009] In some embodiments, the second regulating component includes: The second support is connected to the output end of the first adjustment component; A guide rail is mounted on the second support and extends along the second direction; The second screw extends in the second direction and is rotatably mounted on the second support; The second sliding seat is slidably fitted onto the guide rail and threadedly fitted onto the second screw; the third adjusting assembly is fixedly mounted on the second sliding seat; and The third driving component is driven to one end of the second screw and is used to drive the second screw to rotate. The second sliding block moves linearly along the second direction under the constraint of the guide rail.
[0010] In some embodiments, the third adjustment component includes: The third support is connected to the output end of the second adjustment component; The second guide post is disposed on the third support and extends in the third direction; The third screw extends along a third direction and is rotatably mounted on the third support; The third sliding seat is slidably sleeved on the second guide post and threadedly engaged with the third screw; the angle adjustment component is mounted on the third sliding seat. A second transmission structure is mounted on the third support, and the output end of the second transmission structure is connected to the third screw; and The fourth driving component has its output end connected to the input end of the second transmission structure. The fourth driving component is used to provide rotational power and drives the third screw to rotate after being reversed by the second transmission structure. The third sliding seat moves linearly along the third direction under the constraint of the second guide post.
[0011] In some embodiments, the angle adjustment component includes: The first connecting plate is connected to the output end of the third adjustment component; The second connecting plate is disposed below the first connecting plate and is rotatably connected to one side of the first connecting plate via a rotating shaft. The clamping mechanism is connected to the second connecting plate, and the second connecting plate is provided with a slot. A fourth screw extends along a second direction and is threadedly connected to the first connecting plate; and A sliding member is disposed at one end of the fourth screw and is slidably fitted into the slot. The fourth screw is used to drive the slider to move linearly along the second direction. The slider moves relative to the groove to drive the second connecting plate to rotate around the rotating shaft, so as to adjust the clamping angle of the clamping mechanism.
[0012] In some embodiments, the output end of the third adjustment component is provided with a slider, and the first connecting plate is provided with a groove that cooperates with the slider. The groove extends along the third direction, and the first connecting plate is slidably connected to the output end of the third adjustment component through the cooperation of the slider and the groove.
[0013] In some embodiments, the angle adjustment range of the angle adjustment component is between -15° and +15°.
[0014] In some embodiments, the positioning base includes: Mounting plate, on which the adjustment mechanism is mounted; An expansion joint, mounted on the mounting plate and extending downwards, is inserted into the insertion hole of the upper tube seat and expands to tighten; and A support pin, spaced apart from the expansion joint, is installed on the lower side of the mounting plate and extends downward to abut against the end face of the upper tube seat for support.
[0015] In some embodiments, the mounting plate is further provided with an observation window, which is located in the middle of the mounting plate.
[0016] This application embodiment also provides a method for clamping the expansion joint of a nuclear fuel assembly, using the expansion joint clamping device described above, including the following steps: The positioning base is installed on the upper tube seat of the nuclear fuel assembly; Operate the adjustment mechanism to adjust the clamping posture of the clamping mechanism so that the clamping surface is aligned with and fits against the outer wall of the expansion joint; The first driving member is controlled to drive the first and second grippers to move relative to each other, clamping the expansion joint so as to constrain the circumferential rotation of the expansion joint through the clamping surface when installing or removing screws.
[0017] The beneficial effects of the expansion tube clamping device provided in this application are as follows: the device is reliably fixed to the upper tube seat by the positioning base, providing a stable foundation for subsequent clamping operations; the clamping mechanism is driven to move by the adjustment mechanism, enabling the device to flexibly align with expansion tubes at different positions, adapting to the narrow space of densely packed fuel assembly tube arrays; the contact area is increased by the contact between the clamping surface and the outer wall of the expansion tube, avoiding stress concentration damage to the tube body; the first driving component drives the first and second clamps to move relative to each other to clamp the expansion tube, and the clamping surface hugs the tube wall from both sides, generating sufficient friction to constrain the circumferential rotation of the expansion tube, thereby eliminating the possibility of the screw rotating synchronously with the expansion tube at the source, allowing the screw to be screwed out or screwed in normally, and the whole process does not require close manual contact, meeting the requirements of safe, efficient and non-destructive disassembly and assembly operations in a radioactive environment. Attached Figure Description
[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0019] Figure 1 This is a schematic diagram of the expansion joint clamping device provided in this application embodiment installed on the upper pipe seat; Figure 2 for Figure 1A three-dimensional structural diagram of the adjustment mechanism and clamping mechanism shown; Figure 3 for Figure 1 A three-dimensional structural schematic diagram of the first adjustment component shown; Figure 4 for Figure 1 The diagram shows the structure of the second adjustment component, the third adjustment component, the angle adjustment component, and the clamping mechanism. Figure 5 for Figure 1 The diagram shows the structure of the angle adjustment component and the clamping mechanism. Figure 1 ; Figure 6 for Figure 1 The diagram shows the structure of the angle adjustment component and the clamping mechanism. Figure 2 ; Figure 7 for Figure 1 The diagram shows a top view of the angle adjustment assembly and clamping mechanism. Figure 8 for Figure 7 Schematic diagram of the cross-sectional structure along line AA; Figure 9 for Figure 1 The side view of the angle adjustment assembly and clamping mechanism is shown in the diagram. Figure 10 for Figure 9 Schematic diagram of the cross-sectional structure along line BB; Figure 11 for Figure 1 The diagram shows the structure of the positioning mechanism. Figure 1 ; Figure 12 for Figure 1 The diagram shows the structure of the positioning mechanism. Figure 2 ; Figure 13 The schematic diagram of the upper tube seat shown in the embodiment of this application Figure 1 ; Figure 14 A schematic diagram of the upper tube seat provided in the embodiments of this application. Figure 2 ; Figure 15 This is a top view of the upper tube seat provided in an embodiment of this application; Figure 16 This is a schematic flowchart of the expansion joint clamping method provided in the embodiments of this application.
[0020] The following are the labeling elements in the figure: 10-Positioning base; 11-Mounting plate; 110-Observation window; 12-Expansion joint; 13-Support pin; 14-Lifting pin; 20-Adjusting mechanism; 21-First adjusting assembly; 211-First support; 212-First guide post; 213-First screw; 214-First sliding seat; 215-First transmission structure; 216-Second driving member; 22-Second adjusting assembly; 221-Second support; 2211-Marking: 222-Guide rail; 223-Second screw; 224-Second sliding seat; 225-Third driving member; 23-Third adjusting assembly; 23 1-Third support; 232-Second guide post; 233-Third screw; 234-Third sliding seat; 235-Second transmission structure; 236-Fourth driving component; 24-Angle adjustment assembly; 241-First connecting plate; 2411-Slide groove; 242-Second connecting plate; 2421-Gate; 243-Fourth screw; 244-Slider; 245-Rotating shaft; 246-Fourth guide cup; 247-Roller bearing; 248-Sliding component; 30-Clamping mechanism; 31-First driving component; 32-First gripper; 33-Second gripper; 34-Mounting base; L1 - First direction; L2 - Second direction; L3 - Third direction; 100-Upper tube seat; 101-Insertion hole; 102-Expansion tube; 103-Guide tube; 104-Screw. Detailed Implementation
[0021] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.
[0022] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.
[0023] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, "multiple sets" means two or more sets, "multiple pieces" means two or more pieces, and "several" means one or more, unless otherwise explicitly specified.
[0025] See Figures 10 to 12 After undergoing multiple cycles of irradiation within the reactor, nuclear fuel assemblies require periodic inspection and maintenance to eliminate defects such as damaged fuel rods and ensure the continued safe operation of the assemblies. During the post-irradiation fuel assembly maintenance process, the disassembly of the connecting screw 104 between the upper tube seat 100 and the guide tube 103 is a crucial step in the maintenance work.
[0026] However, in actual maintenance operations, when repairing the expansion joint failure of the expansion tube 102 and guide tube 103 of irradiated nuclear fuel assemblies, a common problem arises during the disassembly and assembly of screw 104: screw 104 rotates synchronously with the expansion tube 102, making normal disassembly and assembly impossible. When disassembling the sleeve screw 104 of the upper tube seat 100, the expansion joint failure causes screw 104 and the expansion tube 102 to become an integral linkage, rotating synchronously, preventing screw 104 from being properly removed from the sleeve. Therefore, a dedicated device is needed to effectively prevent screw 104 from rotating along with the tube, to meet the requirements of safe, efficient, and non-destructive disassembly and assembly operations in a radioactive environment.
[0027] Based on this, this application provides an expansion joint clamping device and clamping method for clamping the upper tube seat expansion joint in nuclear fuel assemblies of nuclear power plants, in order to solve the above-mentioned problems.
[0028] Please refer to the following: Figures 1 to 13 The expansion joint clamping device provided in this application embodiment is applicable, but not limited to, clamping operations on sleeve screws 104 that cannot be properly disassembled due to expansion joint failure during the maintenance of nuclear fuel assemblies in nuclear power plants. In this application embodiment, the first direction L1 is the left-right direction, the second direction L2 is the vertical direction, and the third direction L3 is the front-back direction.
[0029] In the embodiments of this application, such as Figure 1 , Figure 2 , Figure 5 as well as Figure 14As shown, the expansion joint clamping device includes a positioning base 10, an adjustment mechanism 20, and a clamping mechanism 30. The positioning base 10 is used to install on the upper tube seat 100 of the nuclear fuel assembly, providing an installation foundation and support positioning for the entire device. The adjustment mechanism 20 is disposed on the positioning base 10 and is used to adjust the spatial position and clamping posture of the clamping mechanism 30. The clamping mechanism 30 is connected to the output end of the adjustment mechanism 20, and the clamping mechanism 30 can adjust its clamping posture and align with the expansion joint 102 to be inspected under the drive of the adjustment mechanism 20.
[0030] The clamping mechanism 30 includes a first driving member 31, a first gripper 32, and a second gripper 33. The first driving member 31 drives the first gripper 32 and the second gripper 33 to move relative to each other. The first gripper 32 and the second gripper 33 have a clamping surface on one side facing each other that is adapted to the outer wall of the expansion tube 102. During operation, the clamping mechanism 30 moves to the target expansion tube 102 position under the drive of the adjusting mechanism 20. The clamping surface is in contact with the outer wall of the expansion tube 102. The first driving member 31 drives the first gripper 32 and the second gripper 33 to move relative to each other to clamp the expansion tube 102, thereby restricting the circumferential rotation of the expansion tube 102. This effectively prevents the screw 104 from rotating synchronously with the expansion tube 102 when installing or removing the screw 104.
[0031] The expansion tube clamping device provided in this application embodiment first installs the positioning base 10 on the upper tube seat 100 of the nuclear fuel assembly, then operates the adjustment mechanism 20 to adjust the clamping posture of the clamping mechanism 30 so that the clamping surface is aligned and fits against the outer wall of the expansion tube 102, and finally controls the first driving member 31 to drive the first jaw 32 and the second jaw 33 to move relative to each other to clamp the expansion tube 102, so that the circumferential rotation of the expansion tube 102 is constrained by the clamping surface when the screws 104 are installed or removed.
[0032] Thus, the device is reliably fixed to the upper tube seat 100 by the positioning base 10, providing a stable foundation for subsequent clamping operations; the clamping mechanism 30 is driven to move by the adjusting mechanism 20, so that the device can flexibly align with the expansion tube 102 at different positions, adapting to the narrow space of the densely packed fuel assembly tube array; the contact area is increased by the contact between the clamping surface and the outer wall of the expansion tube 102, avoiding stress concentration damage to the tube body; the first driving component 31 drives the first jaw 32 and the second jaw 33 to move relative to each other to clamp the expansion tube 102, and the clamping surface hugs the tube wall from both sides, generating sufficient friction to constrain the circumferential rotation of the expansion tube 102, thereby eliminating the possibility of the screw 104 rotating synchronously with the expansion tube 102 at the source, so that the screw 104 can be screwed out or screwed in normally, and the whole process does not require close contact by humans, meeting the requirements of safe, efficient and non-destructive disassembly and assembly operations in a radioactive environment.
[0033] In the embodiments of this application, such as Figure 4 , Figure 5 , Figure 9 and Figure 10 As shown, the clamping mechanism 30 adopts a single-acting gripper structure. The first driving member 31 is connected to the output end of the adjusting mechanism 20, and the first gripper is fixed in place. The first gripper 32 can be connected to the housing of the first driving member 31. The second gripper 33 is connected to the output end of the first driving member 31. The first driving member 31 is used to drive the second gripper 33 closer to or further away from the first gripper 32 to clamp or release the expansion joint tube 102.
[0034] During operation, the first gripper 32 remains fixed, and the first driving member 31 drives the second gripper 33 to move toward the first gripper 32, so that the first gripper 32 and the second gripper 33 come closer to each other, and the clamping surfaces hug the outer wall of the expansion tube 102 from both sides; when released, the first driving member 31 drives the second gripper 33 to move away from the first gripper 32, so that the two grippers move away from each other and release the constraint on the expansion tube 102.
[0035] Preferably, the first driving component 31 is a cylinder. The clamping action is driven by the cylinder. When the piston rod extends, it drives the second gripper 33 to move to clamp the expansion tube 102. The friction layer provided on the clamping surface increases the friction between the expansion tube 102 and the piston rod, effectively restraining the circumferential rotation and axial movement of the expansion tube 102. When the piston rod retracts, it drives the second gripper 33 to release the expansion tube 102. Of course, the clamping surface can be a V-shaped clamping surface or an arc-shaped clamping surface. When a V-shaped clamping surface is used, a serrated clamping surface can be used to clamp the expansion tube 102.
[0036] Thus, by fixing the first gripper 32 and driving the second gripper 33 by the first driving member 31, the transmission chain of the clamping mechanism 30 is simplified. The clamping and releasing actions can be completed by driving the movement of only one side of the gripper. The structure is compact and the response is rapid. The clamping power is provided by the cylinder, the clamping and releasing actions are rapid, and the clamping force is uniform and controllable. Compared with manual clamping, it is more stable and reliable, greatly reducing the labor intensity of operators and improving the efficiency of maintenance work.
[0037] It should be noted that the first driving component 31 is connected to the output end of the adjustment mechanism 20 via the mounting base 34.
[0038] In the embodiments of this application, such as Figures 1 to 5 As shown, the adjustment mechanism 20 adopts a four-degree-of-freedom linkage architecture, including a first adjustment component 21, a second adjustment component 22, a third adjustment component 23, and an angle adjustment component 24.
[0039] Specifically, the first adjustment component 21 is installed on the upper side of the positioning base 10; the second adjustment component 22 is connected to the output end of the first adjustment component 21 and moves along the first direction L1 under the drive of the first adjustment component 21; the third adjustment component 23 is connected to the output end of the second adjustment component 22 and moves along the second direction L2 under the drive of the second adjustment component 22; the angle adjustment component 24 is connected to the output end of the third adjustment component 23 and moves along the third direction L3 under the drive of the third adjustment component 23; and the clamping mechanism 30 is disposed at the output end of the angle adjustment component 24. The angle adjustment component 24 is used to adjust the tilt angle of the clamping mechanism 30. The first direction L1, the second direction L2, and the third direction L3 are arranged perpendicularly to each other, forming a three-dimensional spatial coordinate system.
[0040] Thus, the first adjustment component 21, the second adjustment component 22, and the third adjustment component 23 respectively drive the clamping mechanism 30 to move linearly along three orthogonal directions, realizing translational adjustment in three-dimensional space, allowing the clamping mechanism 30 to reach any position in space; the angle adjustment component 24 drives the clamping mechanism 30 to rotate around a certain axis, realizing tilt adjustment of the clamping angle, so that the clamping surface can fit the outer wall of the expansion tube 102 in the best posture. The three-dimensional translation and one-dimensional rotation constitute a four-degree-of-freedom linkage, which can cover the expansion tube 102 at any position among the twenty-four guide tubes 103 of the fuel assembly, adapt to complex spatial positions and tube postures at different angles, and achieve precise alignment.
[0041] In the embodiments of this application, such as Figures 1 to 3 As shown, the first adjustment component 21 adopts a combination structure of screw drive and guide post, including a first support 211, a first guide post 212, a first screw 213, a first sliding seat 214, a first transmission structure 215, and a second driving component 216.
[0042] Specifically, the first support 211 is mounted on the positioning base 10, serving as the mounting base for the entire first adjustment assembly 21. The first guide post 212 is mounted on the first support 211 and extends along the first direction L1. The first screw 213 extends along the first direction L1 and is rotatably mounted on the first support 211. The first sliding seat 214 is slidably sleeved on the first guide post 212 and threadedly connected to the first screw 213. The second adjustment assembly 22 is mounted on the first sliding seat 214. The output end of the first transmission structure 215 is connected to the first screw 213, and the output end of the second driving member 216 is connected to the input end of the first transmission structure 215, providing rotational power to drive the first screw 213 to rotate after being reversed by the first transmission structure 215.
[0043] The second driving component 216 is used to input rotational power to the first transmission structure 215, and its specific form is not limited. In this embodiment, the rotational power is provided by an external control tool. Preferably, the input end of the first transmission structure 215 is provided with an operation interface, which is a guide cup structure. The guide cup is set vertically (i.e., set along the third direction L3), with its port facing upward, for receiving the rotational power from the external control tool. During operation, the external control tool is inserted into the guide cup from above, and the operator rotates the control tool, transmitting the rotational force to the input end of the first transmission structure 215 through the guide cup, thereby driving the first screw 213 to rotate. The guide cup structure is simple and reliable in operation, and is particularly suitable for the underwater remote manual operation environment of nuclear fuel assemblies. As another optional implementation, the rotational power can also be provided by an active power source. For example, a motor can be connected to the input end of the first transmission structure 215, and the forward and reverse rotation of the motor drives the first transmission structure 215 to operate, thereby driving the first screw 213 to rotate forward and reverse, realizing the automatic reciprocating movement of the first sliding seat 214 along the first direction L1. The use of an electric motor drive enables remote automated control, making it suitable for batch and standardized maintenance operations. Alternatively, other active rotary power sources such as pneumatic motors or hydraulic motors can be connected to the input end of the first transmission structure 215, as long as rotary power can be input to the first transmission structure 215; this application does not limit this specific application.
[0044] During operation, the second driving component 216 inputs rotational power, which, after being reversed by the first transmission structure 215, drives the first screw 213 to rotate. Since the first sliding seat 214 is threadedly connected to the first screw 213 and slidably mounted on the first guide post 212, the first guide post 212 forms a circumferential constraint on the first sliding seat 214, preventing it from rotating synchronously with the first screw 213. This converts the rotational motion of the first screw 213 into linear movement of the first sliding seat 214 along the first direction L1. Thus, by remotely rotating the second driving component 216 using a control tool, the first sliding seat 214 and the second adjustment assembly 22 mounted thereon can be driven to move linearly along the first direction L1, achieving position adjustment of the clamping mechanism 30 in the first direction L1.
[0045] The first transmission structure 215 converts vertical rotational motion into horizontal rotational motion, which can be achieved using a right-angle commutator. The first guide post 212 provides both linear guidance for the first sliding seat 214 and anti-rotation constraint, ensuring smooth movement, no backlash, and high positioning accuracy. The first screw 213 and the first sliding seat 214 are threaded together, possessing self-locking characteristics. After adjustment, the position is stable and will not move due to external forces.
[0046] In the embodiments of this application, such as Figure 1 , Figure 2 and Figure 4As shown, the second adjustment component 22 adopts a structure combining screw drive and guide rail 222, including a second support 221, guide rail 222, second screw 223, second sliding seat 224 and third drive component 225.
[0047] The second support 221 is connected to the output end of the first adjusting component 21, serving as the mounting base for the second adjusting component 22. A guide rail 222 is mounted on the second support 221 and extends along the second direction L2. The second screw 223 extends along the second direction L2 and is rotatably mounted on the second support 221. A second sliding seat 224 is slidably fitted onto the guide rail 222 and threadedly fitted onto the second screw 223. The third adjusting component 23 is fixedly mounted on the second sliding seat 224. A third driving member 225 is drivenly connected to one end of the second screw 223, used to drive the second screw 223 to rotate.
[0048] The third driving component 225 is used to input rotational power to the second screw 223, and its specific form is not limited. In this embodiment, the third driving component 225 is an external control tool (such as a long-handled wrench) that inputs rotational power through an operating interface, which is then converted into linear motion by the second screw 223. Preferably, the end of the second screw 223 is provided with an operating interface, which is a guide cup structure. The guide cup is set vertically with its port facing upward, and is used to receive the rotational force of the external control tool. During operation, the external control tool is inserted into the guide cup from above, and the operator rotates the control tool, transmitting the rotational force to the second screw 223 through the guide cup, driving the second screw 223 to rotate. The guide cup structure is simple and reliable in operation, and is particularly suitable for the underwater remote manual operation environment of nuclear fuel assemblies. As another optional implementation, the end of the second screw 223 can also be driven to connect to the output shaft of a motor, and the second screw 223 is driven to rotate by the forward and reverse rotation of the motor, realizing the automatic reciprocating movement of the second sliding seat 224 along the second direction L2. The use of an electric motor drive enables remote automated control, making it suitable for batch and standardized maintenance operations. Alternatively, other rotary power sources such as pneumatic motors or hydraulic motors can be connected to the end of the second screw 223 for drive, as long as rotary power can be input to the second screw 223; this application does not limit this approach.
[0049] During operation, rotational power is input into the third driving component 225, driving the second screw 223 to rotate. Since the second sliding seat 224 is threadedly engaged with the second screw 223 and slidably engaged on the guide rail 222, the guide rail 222 forms a circumferential constraint on the second sliding seat 224, preventing it from rotating synchronously with the second screw 223. This converts the rotational motion of the second screw 223 into linear movement of the second sliding seat 224 along the second direction L2, driving the third adjusting component 23 and the clamping mechanism 30 to move linearly along the second direction L2, thereby achieving position adjustment of the clamping mechanism 30 in the second direction L2.
[0050] The guide rail 222 can adopt a dovetail groove structure, which has both guiding and load-bearing functions, ensuring smooth movement without axial movement and high positioning accuracy. The third drive component 225 can be internally threaded to form a nut structure, which engages with the second screw 223 and is secured with a set screw to prevent loosening, thus preventing accidental rotation of the second screw 223 due to vibration during operation. In addition, a thrust roller bearing can be installed between the second support 221 and the second screw 223 to bear axial loads, limiting axial movement of the second screw 223 during rotation, ensuring that only the second sliding seat 224 moves linearly along the second direction L2, thereby improving transmission accuracy and reliability.
[0051] A mark 2211 is provided on the second support 221, which is used to indicate the displacement of the second sliding seat 224 along the second direction L2. For example, the mark 2211 can be a scale line or scale mark arranged along the second direction L2, and a pointer or indicator line can be correspondingly provided on the second sliding seat 224. When the second sliding seat 224 moves along the second direction L2 under the drive of the second screw 223, the operator can read the real-time displacement of the second sliding seat 224 in the second direction L2 through the scale value corresponding to the indicator line on the second sliding seat 224, thereby accurately controlling the adjustment stroke and avoiding repeated alignment and trial and error. Thus, through the indicative function of the mark, the operator can intuitively judge the position of the clamping mechanism in each direction when working remotely underwater, improving adjustment efficiency and alignment accuracy, reducing repeated adjustment operations caused by uncertain position, and further reducing on-site operation time and radiation exposure risk.
[0052] In the embodiments of this application, such as Figure 2 and Figure 4 As shown, the third adjustment component 23 adopts a structure combining screw drive and guide post guidance, including a third support 231, a second guide post 232, a third screw 233, a third sliding seat 234, a second transmission structure 235, and a fourth driving component 236.
[0053] Specifically, the third support 231 is connected to the output end of the second adjusting component 22, serving as the mounting base for the third adjusting component 23. The second guide post 232 is mounted on the third support 231 and extends along the third direction L3. The third screw 233 extends along the third direction L3 and is rotatably mounted on the third support 231. The third sliding seat 234 is slidably sleeved on the second guide post 232 and threadedly engaged with the third screw 233. The angle adjusting component 24 is mounted on the third sliding seat 234. The second transmission structure 235 is mounted on the third support 231, and its output end is connected to the third screw 233. The fourth driving member 236 provides rotational power, driving the third screw 233 to rotate after being reversed by the second transmission structure 235.
[0054] The fourth driving component 236 is used to input rotational power to the second transmission structure 235, and its specific form is not limited. In this embodiment, the rotational power is provided by an external control tool. Preferably, the input end of the second transmission structure 235 is provided with an operation interface, which is a guide cup structure. The guide cup is set vertically (i.e., along the third direction L3), with its port facing upward, for receiving the rotational power from the external control tool. During operation, the external control tool (such as a long-handled wrench) is inserted into the guide cup from above, and the operator rotates the control tool, transmitting the rotational force to the input end of the second transmission structure 235 through the guide cup, thereby driving the third screw 233 to rotate. The guide cup structure is simple and reliable in operation, and is particularly suitable for the underwater remote manual operation environment of nuclear fuel assemblies. As another optional implementation, the rotational power can also be provided by an active power source. For example, a motor can be connected to the input end of the second transmission structure 235. The forward and reverse rotation of the motor drives the second transmission structure 235 to operate, thereby driving the third screw 233 to rotate in both directions, realizing the automatic reciprocating movement of the third sliding seat 234 along the third direction L3. Using a motor drive enables remote automated control, suitable for batch and standardized maintenance operations. Alternatively, other active rotary power sources such as pneumatic motors and hydraulic motors can be connected to the input end of the second transmission structure 235, as long as rotary power can be input to the second transmission structure 235. This application does not limit this specific application.
[0055] During operation, the fourth driving component 236 inputs rotational power, which is reversed by the second transmission structure 235 and drives the third screw 233 to rotate. Since the third sliding seat 234 is threadedly engaged with the third screw 233 and slidably sleeved on the second guide post 232, the second guide post 232 forms a circumferential constraint on the third sliding seat 234, preventing it from rotating synchronously with the third screw 233. This converts the rotational motion of the third screw 233 into linear movement of the third sliding seat 234 along the third direction L3, driving the angle adjustment component 24 and the clamping mechanism 30 to move linearly along the third direction L3, thereby realizing the position adjustment of the clamping mechanism 30 in the third direction L3.
[0056] The second transmission structure 235 converts vertical rotational motion into horizontal rotational motion, allowing external control tools to be inserted vertically into the fourth drive component 236 for operation, adapting to long-distance underwater operations. The second guide post 232 provides both linear guidance for the third sliding seat 234 and anti-rotation constraint, ensuring smooth movement, no backlash, and high positioning accuracy. The third screw 233 and the third sliding seat 234 are threaded together, possessing self-locking characteristics, ensuring stable position after adjustment and preventing movement due to external forces.
[0057] In the embodiments of this application, such as Figures 4 to 6As shown, the angle adjustment assembly 24 includes a first connecting plate 241, a second connecting plate 242, a fourth screw 243, and a sliding member 248.
[0058] Specifically, the first connecting plate 241 is connected to the output end of the third adjusting component 23, serving as the mounting base for the angle adjusting component 24. The second connecting plate 242 is positioned below the first connecting plate 241, with one end of the second connecting plate 242 rotatably connected to one side of the first connecting plate 241 via a rotating shaft 245. The clamping mechanism 30 is fixedly mounted on the second connecting plate 242. A slot 2421 is provided on the second connecting plate 242.
[0059] The fourth screw 243 extends along the second direction L2 and is threadedly connected to the first connecting plate 241. A sliding member 248 is disposed at one end of the fourth screw 243 and slidably fitted within the slot 2421. Preferably, the sliding member 248 includes a slider 244 and a roller bearing 247. The slider 244 is disposed at one end of the fourth screw 243, and the roller bearing 247 is mounted on the slider 244, rollingly fitted within the slot 2421. Through the rolling fit between the roller bearing 247 and the slot 2421, the frictional resistance between the sliding member 248 and the slot 2421 can be effectively reduced, making the angle adjustment process smoother and less strenuous, while also improving adjustment accuracy.
[0060] The angle adjustment assembly 24 also includes a drive component connected to the fourth screw 243, used to input rotational power to the fourth screw 243. In this embodiment, the drive component includes a fourth guide cup 246, which is arranged vertically, and one end of the fourth guide cup 246 is connected to the fourth screw 243. During operation, an external control tool is inserted into the fourth guide cup 246 to input rotational power, driving the fourth screw 243 to rotate. Its specific working principle is as follows: When the clamping angle needs to be adjusted, an external control tool drives the fourth screw 243 to rotate. Since the fourth screw 243 is threadedly engaged with the first connecting plate 241, and the sliding member 248 at the end of the fourth screw 243 is circumferentially constrained by the slot 2421, when the fourth screw 243 rotates, the sliding member 248 cannot rotate with the fourth screw 243, but instead moves along the length of the slot 2421. As the sliding member 248 moves along the slot 2421, it causes the corresponding end of the second connecting plate 242 to move up and down, creating a height difference with the end of the second connecting plate 242 where the pivot 245 is located. This causes the second connecting plate 242 to swing relative to the first connecting plate 241 around the pivot 245, thereby adjusting the clamping angle of the clamping mechanism 30 mounted on the second connecting plate 242.
[0061] Preferably, the fourth screw 243 and the first connecting plate 241 are fitted with a trapezoidal thread. The trapezoidal thread has a self-locking characteristic, which can maintain the stability of the second connecting plate 242's posture by relying on the thread friction after the angle adjustment is completed, preventing angle drift due to vibration or external force. More preferably, the angle adjustment range of the angle adjustment component 24 is between -15° and +15°, that is, the second connecting plate 242 can swing around the rotating shaft 245 within the range of -15° to +15°. This angle range can cover various angle deviations required during the maintenance of the nuclear fuel assembly expansion joint, ensuring that the clamping mechanism 30 can accurately align with the expansion joint 102 to be maintained.
[0062] In this way, the hinged rocker structure combined with the trapezoidal screw drive enables precise and stable adjustment of the clamping angle, allowing the clamping surface to fit the outer wall of the expansion joint 102 in the best posture, compensating for the angle deviation caused by the deformation of the tube after irradiation, and ensuring clamping reliability and anti-rotation effect.
[0063] In the embodiments of this application, such as Figures 4 to 8 As shown, an adaptive sliding structure is provided between the output ends of the angle adjustment component 24 and the third adjustment component 23. The output end of the third adjustment component 23 is provided with a slider 244, and the first connecting plate 241 is provided with a groove 2411 that cooperates with the slider 244. The groove 2411 extends along the third direction L3, and the first connecting plate 241 is slidably connected to the output end of the third adjustment component 23 through the cooperation of the slider 244 and the groove 2411.
[0064] When the clamping mechanism 30 approaches the expansion tube 102 under the drive of the adjusting mechanism 20, and the clamping surface contacts the outer wall of the expansion tube 102, the first connecting plate 241 can slide slightly along the third direction L3 relative to the output end of the third adjusting component 23 through the cooperation of the slider 244 and the slide groove 2411, so that the clamping surface can adaptively fit the outer wall of the expansion tube 102. This sliding structure provides free sliding space along the third direction L3 to compensate for the positional deviation of the clamping mechanism 30 during spatial positioning and the size and positional differences of the expansion tube 102 itself caused by irradiation deformation, manufacturing tolerances, and other factors. When the clamping mechanism 30 clamps the expansion tube 102, the first connecting plate 241 can generate a small displacement along the third direction L3 relative to the front and rear adjustable slide, so that the clamping force is more evenly distributed in the circumferential direction of the tube body, avoiding clamping deviation or local stress concentration caused by rigid connection.
[0065] Thus, through the cooperation of slider 244 and groove 2411, a sliding connection is formed between the first connecting plate 241 and the third adjusting component 23, providing adaptive adjustment capability for the clamping process, ensuring that the clamping surface and the outer wall of the expansion tube 102 maintain the best fit, effectively improving clamping reliability and anti-rotation effect, while avoiding damage to the tube body due to alignment error, and meeting the safety and quality requirements of precision maintenance of nuclear fuel assemblies.
[0066] In the embodiments of this application, such as Figures 5 to 8 As shown, the angle adjustment range of the angle adjustment component 24 is set between -15° and +15°. Specifically, when the second connecting plate 242 is parallel to the first connecting plate 241, the angle of the angle adjustment component 24 is 0°; when the second connecting plate 242 swings around the axis 245 toward the direction closer to the first connecting plate 241, the angle is negative; when the second connecting plate 242 swings toward the direction away from the first connecting plate 241, the angle is positive. In other words, -15° to +15° means that the tilt angle of the second connecting plate 242 relative to the first connecting plate 241 is continuously adjustable within this range, that is, the central axis of the clamping mechanism 30 can be finely adjusted within a range of ±15° from the theoretical installation axis. In specific applications, the angle adjustment value of the angle adjustment component 24 can be -15°, 0°, +15°, or any value between -15° and +15°. For example, the angle adjustment value of the angle adjustment component 24 can be -15°, -12°, -9°, -6°, -3°, 0°, 3°, 6°, 9°, 12°, or 15°.
[0067] The angle range is determined based on the actual deformation and spatial attitude deviation of the fuel assembly expansion tube 102 after irradiation. Specifically, after the nuclear fuel assembly undergoes multiple cycles of irradiation in the reactor, it is affected by neutron irradiation, thermal stress, and creep effects. The guide tube 103 and the expansion tube 102 may experience slight bending or positional displacement, and there is usually a certain angular deviation between their axial direction and the theoretical installation direction. By setting the adjustment range of the angle adjustment component 24 to -15° to +15°, that is, the second connecting plate 242 can swing around the hinge end within a range of ±15 degrees, it is sufficient to compensate for the angular deviation caused by the deformation of the tube body of the expansion tube 102 after irradiation. This allows the clamping surface to be further fine-tuned on the basis of three-dimensional translational positioning, so as to fit the outer wall of the expansion tube 102 at the optimal angle, ensuring clamping reliability and anti-rotation effect. At the same time, this angle range takes into account the movement space requirements of the clamping mechanism 30 in the dense array of fuel assemblies. It provides sufficient adjustment margin to cover angle deviations under various actual working conditions, while avoiding interference between the clamping mechanism 30 and adjacent guide tubes 103 or other structures of the fuel assembly due to excessive adjustment range, thus ensuring safe and stable operation of the device in a confined space.
[0068] In the embodiments of this application, such as Figure 1 , Figure 11 and Figure 12 As shown, the positioning base 10 adopts an expansion joint fixing structure, including a mounting plate 11, an expansion joint 12, and a support pin 13.
[0069] The mounting plate 11 serves as the support platform for the positioning base 10, and the adjustment mechanism 20 is mounted on the upper side of the mounting plate 11. An expansion joint 12 is mounted on the mounting plate 11 and extends downwards to be inserted into the insertion hole 101 of the upper tube seat 100 and expand to tighten. A support pin 13 is spaced apart from the expansion joint 12, mounted on the lower side of the mounting plate 11 and extending downwards to abut against the end face of the upper tube seat 100 for support.
[0070] During installation, the expansion joint 12 is first inserted into the insertion hole 101 of the upper tube seat 100 to the set depth. At this time, the support pin 13 moves down with the mounting plate 11 and abuts against the end face of the upper tube seat 100, forming a vertical support for the mounting plate 11. Then, by screwing the upper end of the expansion joint 12, its lower end expands radially within the hole, tightening within the hole wall, thus locking the positioning base 10 to the upper tube seat 100. In this state, the expansion joint 12 bears the radial tightening force, preventing the positioning base 10 from coming out of the hole of the upper tube seat 100; the support pin 13 bears the vertical support force, preventing the device from tilting or sinking under gravity. The two work together to form a double constraint on the positioning base 10 from both axial and radial directions, ensuring the stability of the entire device during operation.
[0071] Thus, through the combination of the expansion joint 12 and the support pin 13, the positioning base 10 can be quickly installed, accurately positioned, and reliably locked on the upper tube seat 100 without the need for external tools or additional fasteners. Disassembly simply requires loosening the expansion joint 12 to release the lock, making the operation convenient and efficient. Simultaneously, this structure is suitable for long-distance underwater operations, providing a stable foundation for subsequent clamping operations and ensuring clamping accuracy and operational safety.
[0072] Furthermore, to facilitate hoisting, the mounting plate 11 is also equipped with a hoisting pin 14. The hoisting pin 14 is fixed to the upper side of the mounting plate 11 and extends upward, for use with the hook or sling of the hoisting equipment to realize the hoisting and relocation of the entire clamping device. In this way, through the cooperation of the hoisting pin 14 and the hoisting equipment, it is easy to hoist the clamping device to the top of the nuclear fuel assembly upper tube seat 100 for installation, or to hoist it away from the work area after the operation is completed, without the need for additional binding or clamping of the device body, avoiding scratches on the device surface or collision damage to the adjustment mechanism 20 and the clamping mechanism 30, thus improving the convenience and safety of the device's transportation.
[0073] In the embodiments of this application, such as Figure 11 and Figure 12 As shown, an observation window 110 is also provided on the mounting plate 11, and the observation window 110 is located in the middle of the mounting plate 11. The observation window 110 runs through the mounting plate 11 in the vertical direction, providing the operator with a visual channel for observation from top to bottom.
[0074] Because the nuclear fuel assemblies are located underwater, operators must use long-handled tools to perform clamping operations from a distance, limiting their field of vision. The observation window 110 allows operators to observe the relative position between the clamping mechanism 30 and the expansion tube 102 in real time while aligning the clamping mechanism 30 with the expansion tube 102. This allows them to determine if the clamping surfaces are aligned and in contact with the tube wall, and to promptly adjust the components of the adjustment mechanism 20 for positional correction. The observation window 110 is located in the center of the mounting plate 11, directly facing the clamping area, providing an unobstructed viewing angle for accurate judgment of the clamping position and orientation.
[0075] In this way, the entire clamping process can be visualized and monitored through the observation window 110, which effectively makes up for the limited field of vision in underwater long-distance operations, improves the accuracy and efficiency of clamping alignment, reduces the risk of clamping failure or tube damage due to alignment deviation, and further ensures the safety and reliability of maintenance operations in a radioactive environment.
[0076] It should be noted that the screw in the above embodiment is a trapezoidal screw, and the guide cup is internally threaded to form a nut structure, which is threaded with the trapezoidal screw. A set screw is used to prevent loosening and fix it. The axial load is borne by the thrust roller bearing, which restricts the axial movement of the trapezoidal screw during rotation.
[0077] In the embodiments of this application, see Figures 1 to 3 , Figure 14 and Figure 16 Furthermore, a method for clamping the expansion joint 102 of a nuclear fuel assembly is provided. This method is implemented using the aforementioned expansion joint clamping device and includes the following steps: S11: Install the positioning base 10 onto the upper tube seat 100 of the nuclear fuel assembly.
[0078] Specifically, the expansion joint 12 on the positioning base 10 is inserted into the insertion hole 101 of the upper tube seat 100, so that the support pin 13 abuts against the end face of the upper tube seat 100 to form support. Then, the expansion joint 12 is tightened to expand and tighten at the lower end, thus completing the fixation and positioning of the entire device. This step achieves rapid installation and reliable locking of the positioning base 10 on the upper tube seat 100 through the expansion joint quick-installation structure, providing a stable foundation for subsequent clamping operations.
[0079] S12: Operate the adjustment mechanism 20 to adjust the clamping posture of the clamping mechanism 30 so that the clamping surface is aligned with and fits against the outer wall of the expansion tube 102.
[0080] Specifically, in the coarse adjustment stage, the guide cups of the first adjustment component 21, the second adjustment component 22, and the third adjustment component 23 are rotated sequentially using a control tool. This drives the clamping mechanism 30 via screw transmission to complete three-dimensional translational adjustment, aligning the clamping mechanism 30 with the expansion joint 102 to be inspected. In the fine adjustment stage, the guide cup of the angle adjustment component 24 is rotated using a control tool, driving the rocker structure to achieve ±15° angle adjustment, ensuring the clamping surface is properly fitted against the outer wall of the expansion joint 102. This step achieves precise alignment of the clamping mechanism 30 through four-degree-of-freedom linkage.
[0081] S13: Control the first drive member 31 to drive the first gripper 32 and the second gripper 33 to move relative to each other, clamp the expansion tube 102, so as to constrain the circumferential rotation of the expansion tube 102 by the clamping surface when removing and installing the screw 104.
[0082] Specifically, the cylinder is controlled to move, and the piston rod drives the movable clamp to clamp the expansion tube 102. The friction layer on the clamping surface increases the friction force, constraining the circumferential rotation and axial movement of the expansion tube 102. This step achieves rapid and stable clamping through pneumatic drive, fundamentally preventing the expansion tube 102 from rotating when the screw 104 is removed.
[0083] Once the expansion joint 102 is reliably clamped and in an anti-rotation state, the screw 104 can be installed or removed. After completion, control the first drive unit 31 to release the grippers, adjust the reset of each mechanism, and then move the device to clamp the expansion joint 102 at the next guide tube 103 position.
[0084] Thus, by coordinating the three steps of installation positioning, adjustment alignment, and clamping anti-rotation, the expansion joint 102 is quickly positioned, accurately aligned, and reliably clamped, ensuring that the expansion joint 102 does not rotate circumferentially or move axially during the disassembly and assembly of the screw 104. This effectively solves the problem of the screw 104 and the expansion joint 102 rotating synchronously and being unable to be disassembled and assembled normally after the expansion joint fails. The operation is simple and efficient, and it is suitable for long-distance underwater radioactive operation environments.
[0085] The description of the various embodiments above tends to emphasize the differences between the various embodiments. The similarities or similarities between them can be referred to, and for the sake of brevity, they will not be repeated here.
[0086] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. An expansion joint clamping device, characterized by include: Positioning base, used for installation on the upper tube seat of the nuclear fuel assembly; The adjustment mechanism is mounted on the positioning base; as well as A clamping mechanism is connected to the output end of the adjustment mechanism, and the clamping mechanism can adjust its clamping posture and align itself with the expansion joint to be repaired under the drive of the adjustment mechanism. The clamping mechanism includes a first driving member, a first gripper and a second gripper. The first driving member is used to drive the first gripper and the second gripper to move relative to each other. The first gripper and the second gripper have a clamping surface adapted to the outer wall of the expansion tube on one side facing each other.
2. The expansion joint clamping device as described in claim 1, characterized in that, The first driving member is connected to the output end of the adjustment mechanism, and the second gripper is connected to the output end of the first driving member. The output end of the first driving member is used to drive the second gripper to move closer to or away from the first gripper in order to clamp or release the expansion joint.
3. The expansion joint clamping device as described in claim 1, characterized in that, The adjustment mechanism includes: The first adjustment component is installed on the upper side of the positioning base; The second adjustment component is connected to the output end of the first adjustment component and moves along the first direction under the drive of the first adjustment component; A third adjustment component is connected to the output terminal of the second adjustment component and moves along a second direction under the drive of the second adjustment component; and An angle adjustment component is connected to the output end of the third adjustment component and moves along a third direction under the drive of the third adjustment component. The clamping mechanism is disposed at the output end of the angle adjustment component, and the angle adjustment component is used to adjust the tilt angle of the clamping mechanism. The first direction, the second direction, and the third direction are arranged perpendicularly to each other.
4. The expansion joint clamping device as described in claim 3, characterized in that, The first adjustment component includes: The first support is installed on the positioning base; The first guide post is mounted on the first support and extends along the first direction; A first screw extends along a first direction and is rotatably mounted on the first support; The first sliding seat is slidably sleeved on the first guide post and threadedly connected to the first screw; the second adjusting component is installed on the first sliding seat. A first transmission structure, wherein the output end of the first transmission structure is connected to the first screw; and The second driving member has its output end connected to the input end of the first transmission structure. The second driving member is used to provide rotational power and drives the first screw to rotate after being reversed by the first transmission structure. The first sliding seat moves linearly along the first direction under the constraint of the first guide post.
5. The expansion joint clamping device as described in claim 3, characterized in that, The second adjustment component includes: The second support is connected to the output end of the first adjustment component; A guide rail is mounted on the second support and extends along the second direction; The second screw extends in the second direction and is rotatably mounted on the second support; The second sliding seat is slidably fitted onto the guide rail and threadedly fitted onto the second screw; the third adjusting assembly is fixedly mounted on the second sliding seat; and The third driving component is driven to one end of the second screw and is used to drive the second screw to rotate. The second sliding block moves linearly along the second direction under the constraint of the guide rail.
6. The expansion joint clamping device as described in claim 3, characterized in that, The third adjustment component includes: The third support is connected to the output end of the second adjustment component; The second guide post is disposed on the third support and extends in the third direction; The third screw extends along a third direction and is rotatably mounted on the third support; The third sliding seat is slidably sleeved on the second guide post and threadedly engaged with the third screw; the angle adjustment component is mounted on the third sliding seat. A second transmission structure is mounted on the third support, and the output end of the second transmission structure is connected to the third screw; and The fourth driving component has its output end connected to the input end of the second transmission structure. The fourth driving component is used to provide rotational power and drives the third screw to rotate after being reversed by the second transmission structure. The third sliding seat moves linearly along the third direction under the constraint of the second guide post.
7. The expansion joint clamping device as described in claim 3, characterized in that, The angle adjustment component includes: The first connecting plate is connected to the output end of the third adjustment component; The second connecting plate is disposed below the first connecting plate and is rotatably connected to one side of the first connecting plate via a rotating shaft. The clamping mechanism is connected to the second connecting plate, and the second connecting plate is provided with a slot. A fourth screw extends along a second direction and is threadedly connected to the first connecting plate; and A sliding member is disposed at one end of the fourth screw and is slidably fitted into the slot. The fourth screw is used to drive the slider to move linearly along the second direction. The slider moves relative to the groove to drive the second connecting plate to rotate around the rotating shaft, so as to adjust the clamping angle of the clamping mechanism.
8. The expansion joint clamping device as described in claim 7, characterized in that, The output end of the third adjustment component is provided with a slider, and the first connecting plate is provided with a sliding groove that cooperates with the slider. The sliding groove extends along the third direction, and the first connecting plate is slidably connected to the output end of the third adjustment component through the cooperation of the slider and the sliding groove.
9. The expansion joint clamping device according to any one of claims 1 to 8, characterized in that, The angle adjustment range of the angle adjustment component is between -15° and +15°.
10. The expansion joint clamping device according to any one of claims 1 to 8, characterized in that, The positioning base includes: Mounting plate, on which the adjustment mechanism is mounted; An expansion joint, mounted on the mounting plate and extending downwards, is inserted into the insertion hole of the upper tube seat and expands to tighten; and A support pin, spaced apart from the expansion joint, is installed on the lower side of the mounting plate and extends downward to abut against the end face of the upper tube seat for support.
11. The expansion joint clamping device as described in claim 10, characterized in that, An observation window is also provided on the mounting plate, and the observation window is located in the middle of the mounting plate.
12. A method for clamping the expansion joint of a nuclear fuel assembly, characterized in that, The expansion joint clamping device as described in any one of claims 1 to 11 includes the following steps: The positioning base is installed on the upper tube seat of the nuclear fuel assembly; Operate the adjustment mechanism to adjust the clamping posture of the clamping mechanism so that the clamping surface is aligned with and fits against the outer wall of the expansion joint; The first driving member is controlled to drive the first and second grippers to move relative to each other, clamping the expansion joint so as to constrain the circumferential rotation of the expansion joint through the clamping surface when installing or removing screws.