An intelligent assembly device and method for nuclear fuel assembly racks

Abstract

This application provides an intelligent assembly device and method for nuclear fuel assembly grids, relating to the field of grid assembly technology. By setting mutually perpendicular and intersecting channel structures on the fixture body, a precise positioning basis for the strips is provided. During the compression and straightening process, parameters are collected in real time by a detection unit, the control unit determines the straightening state characteristics of the entire strip group, queries the strategy database, and matches the corresponding control strategy to achieve precise termination of the straightening process. This application employs a holistic perception-strategy matching-adaptive execution closed-loop control, which adaptively executes the corresponding compression strategy based on the warp and hardness characteristics of the entire strip group, effectively solving the quality problems of overpressure damage or insufficient straightening of some strip groups in traditional control methods. This intelligent control method significantly improves the consistency and pass rate of assembly quality, fundamentally eliminating the risk of strip damage and ensuring the high reliability of nuclear fuel assembly grid assembly.

Description

Technical Field

[0001] This application generally relates to the field of component grid assembly technology, and specifically to an intelligent assembly device and method for nuclear fuel assembly grids. Background Technology

[0002] The nuclear fuel grid is the core framework of a nuclear fuel assembly, consisting of a honeycomb structure made up of numerous precisely interlocked metal strips. To improve assembly efficiency, existing automated equipment uses a single drive structure to simultaneously drive multiple clamping devices to clamp and shape the entire set of strips. However, this process currently commonly employs a rigid control strategy with fixed force or displacement.

[0003] However, this synchronous drive and unified control strategy faces a fundamental technical problem: due to individual differences in initial warpage and material hardness among different strip groups, the actual stress states of different strip groups vary greatly under the unified control strategy. Strip groups with small overall warpage or low hardness may experience overpressure, resulting in microcracks or indentations, while strip groups with large overall warpage or high hardness may fail to fully straighten due to insufficient clamping force. Consequently, this leads to a high degree of uncertainty in assembly quality and an uncontrollable risk of strip damage. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide an intelligent assembly device and method for nuclear fuel assembly grids that can solve the above-mentioned technical problems.

[0005] In a first aspect, this application provides an intelligent assembly apparatus for a nuclear fuel assembly grid, comprising:

[0006] The clamp body has a plurality of first channels extending along a first horizontal direction, the first channels being used to accommodate first strips, and the plurality of first strips together forming a first strip group; the clamp body also has a plurality of second channels extending along a second horizontal direction, the second channels being used to accommodate second strips; the first channels and the second channels are intersecting; the first horizontal direction is perpendicular to the second horizontal direction;

[0007] Each of the first channels is provided with multiple clamping structures on one side, and each of the clamping structures is connected to a driving structure. The driving structure is used to synchronously drive the clamping structures to apply clamping force laterally to the corresponding first strip.

[0008] A detection unit is mounted on the drive structure and is used to detect the real-time clamping parameters of the clamping structure. The detection unit is electrically connected to a control unit. The control unit is configured to:

[0009] During the orthodontic process, the orthodontic status parameters of the first strip group are determined based on the real-time compression parameters; the orthodontic status parameters include: initial warpage and material hardness;

[0010] The compression control strategy database is queried. The compression control strategy database includes at least: multiple sets of first state parameters and a compression control strategy corresponding to each set of first state parameters; each set of first state parameters includes: an initial warpage range and a material hardness range.

[0011] Traverse the clamping control strategy database, and when it is determined that the orthopedic state parameter matches any set of first state parameters, select the clamping control strategy corresponding to the first state parameter set, and control the drive structure to execute the clamping control strategy;

[0012] The termination of the orthopedic process is controlled based on the real-time clamping parameters.

[0013] According to the technical solution provided in this application, each of the first channels is provided with a plurality of mounting cavities on one side, the mounting cavities are connected to the first channel, and the plurality of mounting cavities are arranged along the first horizontal direction, and the pressing structure is correspondingly disposed in the mounting cavity;

[0014] The clamping structure includes:

[0015] A fixing block is disposed at the top of the mounting cavity; a pushing part is provided at the bottom of the fixing block;

[0016] A top post is movably disposed within the mounting cavity, with one end of the top post away from the fixing block extending out of the mounting cavity and connecting to the drive structure;

[0017] A clamping block is disposed between the fixed block and the top column, and the clamping block is rotatably connected to the top column; the clamping block has a clamping part and a force-receiving part, and the clamping part and the force-receiving part form a first included angle, the opening of the first included angle facing the fixed block; the pushing part is located inside the first included angle;

[0018] The driving structure is used to drive the top column to move toward the fixed block, so that the force-receiving part and the pushing part interact, thereby driving the pressing block to rotate, so that the pressing part applies a uniform pressing force to the corresponding first strip.

[0019] According to the technical solution provided in this application, the first included angle is an acute angle; the outline of the pushing part is adapted to the opening area of ​​the first included angle; when the pressing block rotates to the maximum angle, the edges of the pushing part and the pressing part abut against each other.

[0020] According to the technical solution provided in this application, the detection unit includes:

[0021] A force sensor is disposed on the drive structure and is used to detect the clamping force of the clamping structure.

[0022] A displacement sensor is disposed on the drive structure and is used to detect the pressing displacement of the pressing structure.

[0023] According to the technical solution provided in this application, the detection unit further includes an acoustic emission sensor. Each of the fixed blocks is provided with an acoustic emission sensor on the side near the first strip. The acoustic emission sensor is used to collect acoustic emission parameters during the correction process of the first strip.

[0024] According to the technical solution provided in this application, the driving structure includes:

[0025] A drive plate is disposed at the bottom of the fixture body and is fixedly connected to all the top columns;

[0026] A first driving component is connected to the driving plate and is used to drive the driving plate to move the top column within the mounting cavity.

[0027] According to the technical solution provided in this application, it further includes: a mold frame, the interior of which has a first space, and the clamp body is disposed in the first space; and a grid tray is also movably disposed in the first space, the grid tray being used to push out the formed nuclear fuel assembly grid after assembly.

[0028] Secondly, this application provides an intelligent assembly method for a nuclear fuel assembly grid, implemented using the intelligent assembly device for a nuclear fuel assembly grid described in the first aspect. The method includes the following steps:

[0029] The first strip is placed into the first channel in sequence, and multiple first strips form a first strip group;

[0030] The control drive structure synchronously drives the clamping structure to apply a clamping force laterally to the corresponding first strip;

[0031] During the orthopedic process, the orthopedic state parameters of the first strip group are determined based on the real-time compression parameters; the orthopedic state parameters include: initial warpage and material hardness;

[0032] The compression control strategy database is queried. The compression control strategy database includes at least: multiple sets of first state parameters and a compression control strategy corresponding to each set of first state parameters; each set of first state parameters includes: an initial warpage range and a material hardness range.

[0033] Traverse the clamping control strategy database, and when it is determined that the orthopedic state parameter matches any set of first state parameters, select the clamping control strategy corresponding to the first state parameter set, and control the drive structure to execute the clamping control strategy;

[0034] Based on the real-time clamping parameters, the termination of the orthopedic process is controlled;

[0035] The second strip is placed into the corresponding second channel in sequence, and interlocks with the first strip that has been straightened and fixed to form a nuclear fuel assembly grid.

[0036] According to the technical solution provided in this application, the real-time clamping parameters include: clamping force, clamping displacement, and acoustic emission parameters;

[0037] Based on the real-time clamping parameters, the termination of the orthopedic process is controlled, including the following steps:

[0038] Collect the acoustic emission parameters, clamping force, and clamping displacement emitted by each acoustic emission sensor;

[0039] Determine whether the acoustic emission parameters are less than a first threshold;

[0040] If so, within multiple consecutive preset time windows, the slope of the platform area and the fluctuation of the clamping displacement are determined based on the clamping force and clamping displacement.

[0041] Determine whether the slope of the platform area is less than the second threshold and whether the compression displacement fluctuation is less than the third threshold;

[0042] If so, the orthopedic process is terminated.

[0043] According to the technical solution provided in this application, the following steps are also included:

[0044] When the acoustic emission parameter is determined to be less than the first threshold, the orthopedic process is immediately terminated.

[0045] The beneficial effects of this application are as follows:

[0046] This application provides an intelligent assembly apparatus and method for nuclear fuel assembly grids. The apparatus provides a high-precision positioning and accommodating structure for the first and second strips by setting mutually perpendicular intersecting first and second channels on the fixture body, thus establishing the physical basis for precise assembly. During the clamping and straightening process, clamping parameters are collected in real time by a detection unit. The control unit determines the straightening state characteristics of the entire first strip group based on these parameters, and queries the clamping control strategy database accordingly. It then intelligently matches a clamping control strategy suitable for the current strip group, and finally precisely controls the termination of the straightening process based on the real-time parameters.

[0047] This application employs a holistic perception-strategy matching-adaptive execution-intelligent termination closed-loop control logic, overcoming the limitations of traditional fixed control modes. While maintaining the efficiency advantages of synchronous drive, it adaptively selects and executes a matching clamping control strategy based on the overall warpage and material hardness characteristics of the entire strip assembly. This effectively solves the quality problems in existing technologies where a uniform control strategy results in micro-cracks or indentations in some strip groups due to overpressure, or where some strip groups cannot be fully corrected due to insufficient clamping force. This adaptive control method significantly improves the consistency of assembly quality and product qualification rate, fundamentally eliminating the uncontrollable risk of strip damage and providing a strong guarantee for the high-reliability assembly of nuclear fuel assembly grids. Attached Figure Description

[0048] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0049] Figure 1 This is a schematic diagram of the installation of the first and second strips in an intelligent assembly device for a nuclear fuel assembly grid provided in Embodiment 1 of this application;

[0050] Figure 2 This is a cross-sectional view of an intelligent assembly device for a nuclear fuel assembly grid provided in Embodiment 1 of this application during the installation of the first strip;

[0051] Figure 3 yes Figure 2 A schematic diagram of part A in the middle;

[0052] Figure 4 This is a schematic diagram of an intelligent assembly device for a nuclear fuel assembly grid provided in Embodiment 1 of this application;

[0053] Figure 5 This is a schematic diagram of the grid tray provided in Embodiment 1 of this application;

[0054] Figure 6 This is a flowchart of an intelligent assembly method for a nuclear fuel assembly grid provided in Embodiment 2 of this application.

[0055] In the diagram: 1. Mold frame; 11. Base plate; 12. First side plate; 13. Second side plate; 14. Groove; 2. Fixture body; 3. First channel; 4. Second channel; 5. Mounting cavity; 6. Fixing block; 61. Pushing part; 7. Clamping block; 71. Clamping part; 72. Force-bearing part; 8. Top column; 9. Rotating shaft; 10. Drive plate; 15. Grid tray; 151. Outer frame; 152. Support rod; 16. First strip; 17. Second strip. Detailed Implementation

[0056] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0057] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0058] Example 1

[0059] Please refer to Figures 1-5 This application provides an intelligent assembly device for a nuclear fuel assembly grid, comprising:

[0060] The clamp body 2 has multiple first channels 3 extending along a first horizontal direction. The first channels 3 are used to accommodate first strips 16, and the multiple first strips 16 together constitute a first strip group. The clamp body 2 also has multiple second channels 4 extending along a second horizontal direction. The second channels 4 are used to accommodate second strips 17. The first channels 3 and the second channels 4 are intersected. The first horizontal direction is perpendicular to the second horizontal direction.

[0061] Each first channel 3 has multiple clamping structures on one side, and the multiple clamping structures are all connected to the drive structure. The drive structure is used to synchronously drive the clamping structures to apply clamping force laterally to the corresponding first strip 16.

[0062] The detection unit, mounted on the drive structure, is used to detect the real-time clamping parameters of the clamping structure. The detection unit is electrically connected to the control unit. The control unit is configured to:

[0063] During the orthopedic process, the orthopedic state parameters of the first strip group are determined based on the real-time compression parameters; the orthopedic state parameters include: initial warpage and material hardness;

[0064] The database of compression control strategies is queried. The database of compression control strategies includes at least: multiple sets of first state parameters and a compression control strategy corresponding to each set of first state parameters; each set of first state parameters includes: the initial warpage range and the material hardness range.

[0065] Traverse the compression control strategy database, determine when the orthopedic state parameter matches any set of first state parameters, select the compression control strategy corresponding to the first state parameter set, and control the drive structure to execute the compression control strategy;

[0066] The termination of the orthopedic process is controlled based on real-time clamping parameters.

[0067] For details, please refer to Figure 4 As shown in the figure, a represents the first horizontal direction and b represents the second horizontal direction.

[0068] Specifically, such as Figure 1 and Figure 4 As shown, the fixture body 2 serves as the core positioning element. The fixture body 2 is precision machined with a plurality of first channels 3 extending along a first horizontal direction and a plurality of second channels 4 extending along a second horizontal direction. The first channels 3 are used to accommodate and position the first strips 16, which together constitute the first strip group. The second channels 4 are used to accommodate the second strips 17. The first channels 3 and the second channels 4 are arranged in a crisscross pattern, and the first horizontal direction and the second horizontal direction are perpendicular to each other. This structure provides a precise positioning basis for the strips.

[0069] Specifically, multiple clamping structures are provided on one side of each first channel 3, and these clamping structures are connected to the drive structure. The drive structure adopts a synchronous drive method, which can simultaneously drive all clamping structures to apply precise lateral clamping force to the corresponding first strip 16, creating conditions for precise control while ensuring assembly efficiency.

[0070] In this embodiment, all the first strips 16 in the first strip group are manufactured from the same coil material using a continuous stamping process. Because they originate from the same base material and the manufacturing process is continuous, this group of first strips 16 exhibits high consistency in material properties, thickness distribution, and warpage caused by the coil state; simultaneously, all the first strips 16 have the same length, width, and height. Therefore, the initial warpage and material hardness of this group of first strips 16 before straightening show no significant difference, allowing for unified state assessment and control as a whole.

[0071] Specifically, the detection unit is mounted on the drive structure to detect real-time clamping parameters during the clamping process. The detection unit is electrically connected to the control unit, transmitting the collected data to the control unit in real time. The control unit, as the intelligent core of the entire system, can execute the following adaptive control flow:

[0072] In the initial stage of the orthopedic process, the control unit determines two key orthopedic state parameters of the first strip group based on the real-time clamping parameters collected by the detection unit (in this embodiment, the real-time clamping parameters include clamping force and clamping displacement), namely the initial warpage and material hardness. In specific implementation, the control unit first drives the clamping structure to advance slowly at a low speed of 2mm / s. When it detects that the clamping force suddenly increases from 0 to the first pressure P1 (in this embodiment, the first pressure is 30N), it immediately records the clamping displacement at this moment as the initial contact position x0. Then, it calculates the initial warpage ρ, which characterizes the overall bending degree of the first strip group, using Formula 1.

[0073] Formula 1;

[0074] in, L represents the theoretical height of the first strip 16 in an ideal straight state, and L represents the length of the first strip 16.

[0075] After determining the initial contact position, the drive structure continues to advance the clamping structure, and the clamping force and clamping displacement are collected in real time. When the clamping force increases from the first pressure P1 to the second pressure P2 (in this embodiment, the second pressure is 50N), the clamping displacement at this moment is recorded (in this embodiment, the clamping displacement is detected by a displacement sensor located at the connection between the first drive member and the drive plate 10) as the first contact position x1, and then the formula is used to determine the first contact position x1. The displacement change was calculated. The orthopedic stiffness coefficient was calculated using Formula 2. The straightening stiffness coefficient characterizes the overall resistance to deformation of the first strip group during the initial compression stage.

[0076] Formula 2;

[0077] The pre-stored calibration database is traversed. This database includes multiple straightening stiffness coefficients and the material hardness corresponding to each coefficient. The material hardness (HV) corresponding to the calculated straightening stiffness coefficient is selected, thereby completing an accurate assessment of the material properties of the strip assembly. In this embodiment, within the manufacturing specifications and process window of the nuclear fuel assembly grid strips involved in this application, a large number of representative strip samples are selected and subjected to straightening and hardness tests to establish an empirical correspondence dataset between the straightening stiffness coefficient and the material hardness.

[0078] Specifically, the control unit internally stores a database of clamping control strategies established through extensive process testing. This database is optimized using experimental design methods such as Box-Behnken, with optimization targets of strip flatness ≤0.05mm and residual stress ≤120MPa. The clamping control strategy database contains multiple sets of first-state parameters and their corresponding clamping control strategies. Each set of first-state parameters includes the initial warpage range and the material hardness range.

[0079] The control unit traverses and queries the clamping control strategy database, matches the orthopedic state parameters with the first set of state parameters in the database, selects the clamping control strategy corresponding to the first set of state parameters, and controls the drive structure to execute the clamping control strategy. For example, when ρ < 0.3% and HV < 160, the clamping control strategy is the high-speed direct mode (i.e., the drive structure drives the clamping structure at full speed to clamp the first strip 16 without pressure holding); when 0.3% ≤ ρ ≤ 0.8% or 160 ≤ HV ≤ 200, the clamping control strategy is the standard pressure holding mode (i.e., the target clamping force is 180N, and the pressure is held for 2S); when ρ > 0.8% or HV > 200, the clamping control strategy is the low-stress multi-stage pressure holding mode (i.e., the clamping force is increased in stages).

[0080] Working Principle: The overall perception-strategy matching-adaptive execution-intelligent termination closed-loop control logic adopted in this application breaks through the limitations of traditional fixed control modes. While maintaining the efficiency advantages of synchronous drive, it can adaptively select and execute a matching clamping control strategy based on the overall warpage and material hardness characteristics of the entire strip assembly. This effectively solves the quality problems caused by the use of a unified control strategy in existing technologies, such as micro-cracks or indentations in some strip groups due to overpressure, or incomplete straightening of some strip groups due to insufficient clamping force. This adaptive control method significantly improves the consistency of assembly quality and product qualification rate, fundamentally eliminating the uncontrollable risk of strip damage and providing a strong guarantee for the high-reliability assembly of nuclear fuel assembly grids.

[0081] In some embodiments, each first channel 3 has a plurality of mounting cavities 5 on one side, the mounting cavities 5 are connected to the first channel 3, and the plurality of mounting cavities 5 are arranged along the first horizontal direction, with the pressing structure correspondingly disposed in the mounting cavity 5.

[0082] The clamping structure includes:

[0083] A fixing block 6 is provided at the top of the mounting cavity 5; a pushing part 61 is provided at the bottom of the fixing block 6.

[0084] Top post 8 is movably disposed in mounting cavity 5, and the end of top post 8 away from fixed block 6 extends out of mounting cavity 5 and is connected to drive structure;

[0085] A clamping block 7 is disposed between a fixed block 6 and a top column 8, and the clamping block 7 is rotatably connected to the top column 8; the clamping block 7 has a clamping part 71 and a force-receiving part 72, and a first included angle is formed between the clamping part 71 and the force-receiving part 72, with the opening of the first included angle facing the fixed block 6; the pushing part 61 is located inside the first included angle;

[0086] The driving structure is used to drive the top column 8 to move toward the fixed block 6 so that the force-receiving part 72 and the pushing part 61 interact, thereby driving the pressing block 7 to rotate, so that the pressing part 71 applies a uniform pressing force to the corresponding first strip 16.

[0087] Specifically, the mounting cavity 5 serves as the carrier of the flexible pressing device, and is arranged along at least one side of each first channel 3 and is connected to the first channel 3; the mounting cavity 5 corresponding to each first channel 3 is arranged along the first horizontal direction to form a distributed pressing point array. This layout ensures uniform, multi-point synchronous pressing of each first strip 16 over its entire length.

[0088] Specifically, such as Figure 2 and Figure 3 As shown, the clamping structure includes: a fixed block 6, a top column 8, and a clamping block 7. The fixed block 6 is fixedly installed on the top of the mounting cavity 5, serving as the static reference for the entire mechanism, and has a pushing part 61 at its bottom. The top column 8 is movably disposed within the mounting cavity 5, serving as a power transmission element. One end of the top column 8, away from the fixed block 6, extends out of the mounting cavity 5 and connects to the drive structure. Under the control of the drive structure, the top column 8 can perform precise linear motion within the mounting cavity 5. The clamping block 7 is disposed between the fixed block 6 and the top column 8, serving as the core component directly performing the clamping function. The clamping block 7 is rotatably connected to the top column 8 via a rotating shaft 9, allowing it to rotate around a fixed axis. The clamping block 7 has two clearly defined clamping parts 71 and force-receiving parts 72. The clamping part 71 is located near the first channel 3, directly contacting the first belt 16. A specific first angle is formed between the clamping part 71 and the force-receiving part 72, and the opening of this first angle faces the fixed block 6, allowing the pushing part 61 of the fixed block 6 to be precisely located within this first angle region.

[0089] During operation, the drive structure drives the top column 8 to move towards the fixed block 6. The top column 8 pushes the force-receiving part 72 of the pressing block 7, causing the force-receiving part 72 to move along the inclined surface of the pushing part 61. Through this cooperation, the linear motion of the top column 8 is converted into the rotational motion of the pressing block 7 around the rotating shaft 9, ultimately causing the pressing part 71 to apply a uniform pressing force to the corresponding first strip 16.

[0090] In some embodiments, the first included angle is an acute angle; the outline of the pushing part 61 is adapted to the opening area of ​​the first included angle; when the clamping block 7 rotates to the maximum angle, the edges of the pushing part 61 and the clamping part 71 abut against each other.

[0091] Specifically, the first included angle of the clamping block 7 is designed as an acute angle (in this embodiment, the first included angle is 60°). This angle selection ensures sufficient clamping stroke while providing optimal structural conditions for mechanical limiting. The contour shape of the pushing part 61 is precisely matched with the opening area of ​​the first included angle, and the two form a complementary geometric relationship.

[0092] When the drive structure pushes the top column 8 upward, the clamping block 7 rotates around the rotating shaft 9, and the clamping part 71 moves in the direction of the first strip 16. During this process, the pushing part 61 always slides within the angle area formed by the force-bearing part 72 and the clamping part 71 of the clamping block 7. When the clamping block 7 rotates to the preset maximum angle, the edges of the pushing part 61 and the clamping part 71 make full contact and abut against each other, thus forming a reliable mechanical hard limit. This mechanical limit structure is used to provide a physical stop, mechanically limiting the maximum clamping stroke, preventing strip overpressure or equipment damage caused by over-stroke, thereby extending the service life of the equipment.

[0093] In some implementations, the detection unit includes:

[0094] A force sensor is mounted on the drive structure and is used to detect the clamping force of the clamping structure.

[0095] The displacement sensor is mounted on the drive structure and is used to detect the clamping displacement of the clamping structure.

[0096] Specifically, the detection unit includes a force sensor and a displacement sensor. The force sensor is mounted on the drive structure and is used to detect in real time the clamping force applied to the first strip 16 by the clamping structure during the straightening process. By monitoring the changes in the clamping force, it is possible to effectively determine whether the clamping state meets the process requirements, and to make timely adjustments or issue an alarm when the force value exceeds the set range, thereby ensuring that the first strip 16 is subjected to uniform force during the straightening process and avoiding deformation defects caused by overpressure or underpressure.

[0097] A displacement sensor is also mounted on the drive structure to detect the amount of displacement of the clamping structure during the clamping process, i.e., the clamping displacement. By collecting displacement data, the system can precisely control the position of the clamping structure, ensuring that the first strip 16 is accurately positioned during the straightening process. Furthermore, it can be combined with force sensor data to achieve closed-loop control of the straightening process, improving straightening accuracy and consistency.

[0098] In some embodiments, the detection unit further includes an acoustic emission sensor, wherein each fixing block 6 is provided with an acoustic emission sensor on the side near the first strip 16, and the acoustic emission sensor is used to collect acoustic emission parameters during the orthopedic process of the first strip 16.

[0099] Specifically, the detection unit also includes acoustic emission sensors. Each fixing block 6 has an acoustic emission sensor installed on the side closest to the first strip 16 to collect acoustic emission parameters, such as elastic waves, generated by the first strip 16 during the straightening process. These acoustic emission parameters can reflect the internal state changes of the material during the stress process, such as the generation and propagation of microcracks and plastic deformation, thus providing important basis for assessing the straightening quality and judging the structural integrity of the first strip 16. By analyzing the frequency, amplitude, and frequency of acoustic emission parameter signals, the system can achieve early identification and warning of abnormal states, further improving the reliability and intelligence level of the straightening process.

[0100] In this embodiment, the surface of the acoustic emission sensor is coated with vacuum grease to ensure acoustic coupling.

[0101] In some implementations, the driving structure includes:

[0102] Drive plate 10 is located at the bottom of fixture body 2 and is fixedly connected to all top posts 8.

[0103] The first driving component is connected to the driving plate 10 and is used to drive the driving plate 10 to move the top column 8 within the mounting cavity 5.

[0104] Specifically, the drive structure includes a drive plate 10 and a first drive component. The drive plate 10 is horizontally positioned at the bottom of the fixture body 2 and serves as an integral power transmission platform. It is rigidly fixed to the bottom of all the top columns 8 by welding, thereby ensuring that all the clamping structures can move synchronously. The first drive component serves as the core power source, and its output end is connected to the drive plate 10 to drive the drive plate 10 to make precise linear movements in the vertical direction, thereby driving all the top columns 8 to move synchronously in their respective mounting cavities 5.

[0105] Specifically, the first driving component can be an electric cylinder, hydraulic cylinder, pneumatic cylinder, or a servo motor combined with a lead screw; preferably, an electric cylinder or servo electric cylinder with closed-loop control is used to provide precise displacement and speed control; in this embodiment, the detection unit (i.e., force sensor and displacement sensor) is set at the connection between the first driving component and the drive plate 10.

[0106] Specifically, this application achieves unified driving of all distributed clamping structures through a single first driving component in conjunction with the overall driving plate 10. This ensures the consistency in timing and magnitude of the multiple clamping forces acting on the first strip 16, fundamentally avoiding displacement or twisting of the first strip 16 due to asynchronous clamping. Simultaneously, this centralized driving structure simplifies the system architecture, improves operational reliability, facilitates integration with the upper-level control system, and enables fully automated assembly cycles.

[0107] In some embodiments, it further includes: a mold frame 1, the interior of which has a first space, and a fixture body 2 disposed in the first space; and a grid tray 15 is also movably disposed in the first space, the grid tray 15 being used to push out the formed nuclear fuel assembly grid after assembly.

[0108] Specifically, such as Figure 4 As shown, the mold frame 1 constitutes the support structure of the entire assembly mold, and the first space inside it provides a stable working environment for precise positioning and assembly operations. The fixture body 2 is fixedly installed in the first space as the core positioning element; in this embodiment, the drive plate 10 is horizontally arranged at the bottom of the mold frame 1.

[0109] Specifically, the mold frame 1 includes: a base plate 11, a first side plate 12, and a second side plate 13; in this embodiment, the base plate 11, the first side plate 12, and the second side plate 13 are integrally formed structures; wherein, the base plate 11 serves as the mounting base of the entire mold, and its upper plane is used to support the fixture body 2; two first side plates 12 are provided, and the two first side plates 12 are respectively provided on both sides of the base plate 11 along the first horizontal direction. The first side plate 12 has a first receiving groove precisely machined on it corresponding to the first channel 3. When the first strip 16 is installed, the first receiving groove and the first channel 3 together form a positioning and support structure for the first strip 16, ensuring that the first strip 16 is reliably positioned in the length direction.

[0110] Similarly, there are two second side plates 13. The two second side plates 13 are respectively set on both sides of the base plate 11 along the second horizontal direction. The second side plates 13 are precisely machined with second receiving grooves corresponding to the second channel 4. When the second strip 17 is installed, the second receiving groove and the second channel 4 together form a positioning and support structure for the second strip 17, ensuring that the second strip 17 is reliably positioned in the length direction.

[0111] Specifically, the assembly mold is also equipped with a grid tray 15, which serves as a key ejection mechanism for achieving automated material handling. The grid tray 15 is movably positioned within the first space of the mold frame 1. During assembly, the grid tray 15 is initially positioned at the bottom of the first space, providing a stable bottom support reference for the assembly of the first strip 16 and the second strip 17. After all strips of the nuclear fuel assembly grid are spliced ​​and clamped, the entire formed nuclear fuel assembly grid is evenly ejected from the channels of the fixture body 2 via the grid tray 15 until the nuclear fuel assembly grid is completely freed from the constraint area of ​​the fixture, facilitating subsequent gripping and transfer by the robotic arm.

[0112] Specifically, in the mold frame 1, grooves 14 extending in the vertical direction are formed between adjacent first side plates 12 and second side plates 13. These grooves 14 are symmetrically distributed in pairs to form a complete guide system.

[0113] like Figure 5 As shown, the grid tray 15 consists of an outer frame 151 and supporting rods 152. The outer frame 151 is a rectangular frame structure, with its two sides extending along the second horizontal direction serving as guides, which are respectively embedded in corresponding grooves 14 to form a sliding connection. This connection method ensures that the grid tray 15 maintains a precise vertical trajectory during lifting and lowering, preventing horizontal deviation or torsion.

[0114] At least two support rods 152, fixed inside the outer frame 151, are arranged in parallel at intervals, with their top support surfaces located on the same horizontal plane, together forming a stable support plane at the bottom of the first space. The arrangement of these support rods 152 is adapted to the bottom structure of the nuclear fuel assembly grid, enabling a uniform force distribution to the grid during support and ejection.

[0115] This structural design achieves precise guidance of the grid tray 15 during the ejection process through the sliding engagement of the outer frame 151 and the groove 14; at the same time, the distributed support of multiple support rods 152 avoids grid deformation caused by concentrated force during ejection. This coordinated design of guidance and support ensures that the formed nuclear fuel assembly grid can be ejected from the mold smoothly and without damage, creating favorable conditions for subsequent automated material handling operations.

[0116] Example 2

[0117] Please refer to Figure 6 This application provides an intelligent assembly method for a nuclear fuel assembly grid, comprising the following steps:

[0118] S100: The first strip is placed into the first channel in sequence, and multiple first strips form a first strip group;

[0119] Specifically, after the assembly process begins, the robotic arm first performs precise positioning under the guidance of the vision recognition system, placing the first strip 16 into the corresponding first channel 3 in sequence, and multiple first strips 16 together form the first strip group.

[0120] S200: The control drive structure synchronously drives the clamping structure to apply a clamping force laterally to the corresponding first strip;

[0121] Specifically, in this embodiment, the driving structure includes a driving plate 10 and a first driving member; the clamping structure includes a fixing block 6, a top column 8 and a clamping block 7, and the specific structure is described in Embodiment 1.

[0122] In the initial state, the drive plate 10 is in its lowest position, and all the clamping blocks 7 do not interfere with the strip. During operation, the first drive member drives the top column 8 to move towards the fixed block 6. The top column 8 pushes the force-receiving part 72 of the clamping block 7, causing the force-receiving part 72 to move along the inclined surface of the push part 61. Through this cooperation, the linear motion of the top column 8 is converted into the rotational motion of the clamping block 7 around the rotating shaft 9, ultimately causing the clamping part 71 to apply a uniform clamping force to the corresponding first strip 16.

[0123] S300: During the orthodontic process, the orthodontic state parameters of the first strip group are determined based on the real-time clamping parameters; the orthodontic state parameters include: initial warpage and material hardness;

[0124] Specifically, the detection unit is mounted on the drive structure to detect real-time clamping parameters during the clamping process. The detection unit is electrically connected to the control unit, transmitting the collected data to the control unit in real time. The control unit, as the intelligent core of the entire system, can execute the following adaptive control flow:

[0125] In the initial stage of the orthopedic process, the control unit determines two key orthopedic state parameters of the first strip group based on the real-time clamping parameters collected by the detection unit (in this embodiment, the real-time clamping parameters include clamping force and clamping displacement), namely the initial warpage and material hardness. In specific implementation, the control unit first drives the clamping structure to advance slowly at a low speed of 2mm / s. When it detects that the clamping force suddenly increases from 0 to the first pressure P1 (in this embodiment, the first pressure is 30N), it immediately records the clamping displacement at this moment as the initial contact position x0. Then, it calculates the initial warpage ρ, which characterizes the overall bending degree of the first strip group, using Formula 1.

[0126] Formula 1;

[0127] in, L represents the theoretical height of the first strip 16 in an ideal straight state, and L represents the length of the first strip 16.

[0128] After determining the initial contact position, the drive structure continues to advance the clamping structure, and the clamping force and clamping displacement are collected in real time. When the clamping force increases from the first pressure P1 to the second pressure P2 (in this embodiment, the second pressure is 50N), the clamping displacement at this moment is recorded (in this embodiment, the clamping displacement is detected by a displacement sensor located at the connection between the first drive member and the drive plate 10) as the first contact position x1, and then the formula is used to determine the first contact position x1. The displacement change was calculated. The orthopedic stiffness coefficient is calculated using Formula 2. The straightening stiffness coefficient characterizes the overall resistance to deformation of the first strip group during the initial compression stage.

[0129] Formula 2;

[0130] The pre-stored calibration database is traversed. This database includes multiple straightening stiffness coefficients and the material hardness corresponding to each coefficient. The material hardness (HV) corresponding to the calculated straightening stiffness coefficient is selected, thereby completing an accurate assessment of the material properties of the strip assembly. In this embodiment, within the manufacturing specifications and process window of the nuclear fuel assembly grid strips involved in this application, a large number of representative strip samples are selected and subjected to straightening and hardness tests to establish an empirical correspondence dataset between the straightening stiffness coefficient and the material hardness.

[0131] S400: Query the clamping control strategy database. The clamping control strategy database includes at least: multiple sets of first state parameters and clamping control strategies corresponding to each set of first state parameters; each set of first state parameters includes: the initial warpage range and the material hardness range.

[0132] S500: Traverse the clamping control strategy database, determine when the orthopedic state parameter matches any set of first state parameters, select the clamping control strategy corresponding to the first state parameter set, and control the drive structure to execute the clamping control strategy;

[0133] Specifically, the control unit internally stores a database of clamping control strategies established through extensive process testing. This database is optimized using experimental design methods such as Box-Behnken, with optimization targets of strip flatness ≤0.05mm and residual stress ≤120MPa. The clamping control strategy database contains multiple sets of first-state parameters and their corresponding clamping control strategies. Each set of first-state parameters includes the initial warpage range and the material hardness range.

[0134] The control unit traverses and queries the clamping control strategy database, matches the orthopedic state parameters with the first set of state parameters in the database, selects the clamping control strategy corresponding to the first set of state parameters, and controls the drive structure to execute the clamping control strategy. For example, when ρ < 0.3% and HV < 160, the clamping control strategy is the high-speed direct mode (i.e., the drive structure drives the clamping structure at full speed to clamp the first strip 16 without pressure holding); when 0.3% ≤ ρ ≤ 0.8% or 160 ≤ HV ≤ 200, the clamping control strategy is the standard pressure holding mode (i.e., the target clamping force is 180N, and the pressure is held for 2S); when ρ > 0.8% or HV > 200, the clamping control strategy is the low-stress multi-stage pressure holding mode (i.e., the clamping force is increased in stages).

[0135] S600: Based on real-time clamping parameters, control the termination of the orthopedic process;

[0136] Specifically, the real-time compression parameters also include: acoustic emission parameters; acoustic emission parameters specifically refer to the root mean square value of the acoustic emission signal, which is collected by the acoustic emission sensor installed on each fixed block 6, and can sensitively characterize the dynamic process of internal micro-deformation and stress release of the first strip 16 during the straightening process.

[0137] Further, step S600 includes the following steps:

[0138] S610: Collects acoustic emission parameters, clamping force, and clamping displacement emitted by each acoustic emission sensor;

[0139] Specifically, the system uses a sampling frequency of 1kHz to synchronously and in real-time collect three key physical quantities: acoustic emission parameters (i.e., the root mean square value of the acoustic emission signal), clamping force, and clamping displacement through force sensors and displacement sensors arranged on the drive structure, as well as acoustic emission sensors installed on each fixed block 6. This step provides a high-fidelity, synchronously timed data foundation for subsequent intelligent judgment.

[0140] S620: Determine whether the acoustic emission parameters are less than the first threshold;

[0141] Specifically, the system determines whether the collected acoustic emission parameters are less than a first threshold (e.g., 0.015). This step aims to monitor the microscopic activity within the strip. If the acoustic emission parameters are lower than the first threshold, it indicates that violent energy release events such as plastic deformation, microcrack generation and propagation within the material have essentially ceased, and the strip has entered a stable state dominated by stress relaxation.

[0142] S630: If so, within multiple consecutive preset time windows, determine the slope of the platform area and the fluctuation of the clamping displacement based on the clamping force and clamping displacement;

[0143] Specifically, if the acoustic emission parameters meet the conditions, the control unit immediately enters multiple analysis windows, each lasting 50ms. Within these analysis windows, the system performs dynamic calculations based on the real-time acquired clamping force and clamping displacement data:

[0144] Determine the slope k1 of the plateau region: Perform linear fitting on the plateau region of the force-displacement curve and calculate the slope k1 of the plateau region (unit: N / µm); the slope of the plateau region characterizes the rate of change of the clamping force under small displacement.

[0145] Calculate the compression displacement fluctuation σ(x): Calculate the standard deviation σ(x) (unit: µm) of the compression displacement data within the preset time window to quantify the stability of the position between the strip and the mold.

[0146] S640: Determine whether the slope of the platform area is less than the second threshold and whether the compression displacement fluctuation is less than the third threshold;

[0147] Specifically, when the slope of the platform area is less than the second threshold and the compression displacement fluctuation is less than the third threshold, it indicates that the first strip group has reached the end point of complete mold application; conversely, when the slope of the platform is not less than the second threshold and / or the compression displacement fluctuation is not less than the third threshold, it indicates that the correction process has not been completed and compression needs to continue.

[0148] S650: If so, the orthopedic process is terminated.

[0149] Specifically, when the slope k1 of the platform area is less than the second threshold (e.g., 0.01 N / µm), it indicates that the clamping force has stabilized, the strip has been completely pressed into the mold cavity, and it has lost the ability to undergo further macroscopic plastic deformation.

[0150] When the clamping displacement fluctuation σ(x) is less than the third threshold (e.g., 2µm), it indicates that there is no detectable relative micro-motion between the clamping system and the strip, and the mechanical state is highly stable.

[0151] If the slope k1 of the platform area and the pressure displacement fluctuation σ(x) both meet the conditions within three consecutive 50ms preset time windows, the control unit immediately determines that the first strip group has reached the end point of complete mold application and then sends a braking command to the drive structure (electric cylinder) to control the correction process to terminate precisely and automatically.

[0152] Furthermore, it also includes the following steps:

[0153] S660: When the acoustic emission parameter is determined to be less than the first threshold, the orthopedic process is immediately terminated.

[0154] Specifically, if the control unit determines that the acoustic emission parameter is less than a first threshold (in this embodiment, the first threshold is 0.015), it indicates that an abnormal and violent energy release event may be occurring inside the first strip 16 during the correction process. This situation usually points to the rapid propagation of microcracks or excessive plastic deformation, and is a critical signal that the first strip 16 is about to be damaged or has already been damaged.

[0155] At this point, the control unit determines this situation as a serious abnormality. In order to prevent potential latent cracks from expanding into macroscopic defects and to prevent strips with damage risks from flowing into subsequent processes, the control system will immediately trigger the highest priority emergency stop command, forcing the first drive component (electric cylinder) to stop and retract, unconditionally terminating this straightening process.

[0156] This step, together with force sensors and mechanical hard stops, constitutes a triple protection mechanism combining active and passive measures. It particularly focuses on preventing internal damage that is not visible to the naked eye and is a key technical measure to achieve the quality target of zero outflow of latent cracks.

[0157] S700: The second strip is placed into the corresponding second channel in sequence, and interlocks with the first strip that has been straightened and fixed to form a nuclear fuel assembly grid.

[0158] Specifically, after the first strip group is pressed and fixed, the robotic arm is positioned again according to the vision recognition system, and the second strip 17 is placed into the second channel 4 in sequence, intersecting and fitting with the fixed first strip 16 to form a grid structure, thereby completing the assembly of the nuclear fuel assembly grid.

[0159] Specifically, after assembly, the first driving component drives the driving plate 10 to move downward, so that the clamping part 71 of the clamping block 7 moves away from the first strip 16, completely releasing the constraint on the first strip 16; then the electric cylinder drives the grid tray 15 to rise steadily, lifting the formed nuclear fuel assembly grid as a whole and pushing it out of the fixture body 2, ensuring that the assembly grid smoothly leaves the mold and reaches the predetermined material picking station, and finally completing the entire automated assembly cycle.

[0160] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. An intelligent assembly device for a nuclear fuel assembly grid, characterized in that, include: The clamp body (2) is provided with a plurality of first channels (3) extending along a first horizontal direction. The first channels (3) are used to accommodate first strips (16), and the plurality of first strips (16) together constitute a first strip group. The clamp body (2) is also provided with a plurality of second channels (4) extending along a second horizontal direction. The second channels (4) are used to accommodate second strips (17). The first channels (3) and the second channels (4) are intersected. The first horizontal direction is perpendicular to the second horizontal direction. Each of the first channels (3) has multiple clamping structures on one side, and the multiple clamping structures are connected to the driving structure. The driving structure is used to synchronously drive the clamping structures to apply clamping force laterally to the corresponding first strip (16). A detection unit is disposed on the drive structure and is used to detect the real-time clamping parameters of the clamping structure; the detection unit is electrically connected to the control unit. The control unit is configured to: During the orthodontic process, the orthodontic status parameters of the first strip group are determined based on the real-time compression parameters. The orthopedic state parameters include: initial warpage and material hardness; The compression control strategy database is queried. The compression control strategy database includes at least: multiple sets of first state parameters and a compression control strategy corresponding to each set of first state parameters; each set of first state parameters includes: an initial warpage range and a material hardness range. Traverse the clamping control strategy database, and when it is determined that the orthopedic state parameter matches any set of first state parameters, select the clamping control strategy corresponding to the first state parameter set, and control the drive structure to execute the clamping control strategy; The termination of the orthopedic process is controlled based on the real-time clamping parameters.

2. The intelligent assembly device for a nuclear fuel assembly grid according to claim 1, characterized in that, Each of the first channels (3) has multiple mounting cavities (5) on one side. The mounting cavities (5) are connected to the first channels (3), and the multiple mounting cavities (5) are arranged along the first horizontal direction. The pressing structure is correspondingly installed in each mounting cavity (5). The clamping structure includes: A fixing block (6) is disposed at the top of the mounting cavity (5); a pushing part (61) is disposed at the bottom of the fixing block (6). Top post (8), the top post (8) is movably disposed in the mounting cavity (5), and the end of the top post (8) away from the fixing block (6) extends out of the mounting cavity (5) and is connected to the driving structure; A clamping block (7) is disposed between the fixing block (6) and the top column (8), and the clamping block (7) is rotatably connected to the top column (8); the clamping block (7) has a clamping part (71) and a force-receiving part (72), and a first included angle is formed between the clamping part (71) and the force-receiving part (72), and the opening of the first included angle faces the fixing block (6); the pushing part (61) is located inside the first included angle; The driving structure is used to drive the top column (8) to move toward the fixed block (6) so that the force-receiving part (72) and the pushing part (61) interact, thereby driving the pressing block (7) to rotate, so that the pressing part (71) applies a uniform pressing force to the corresponding first strip (16).

3. The intelligent assembly device for a nuclear fuel assembly grid according to claim 2, characterized in that, The first included angle is an acute angle; the outline of the pushing part (61) is adapted to the opening area of ​​the first included angle; when the pressing block (7) rotates to the maximum angle, the edges of the pushing part (61) and the pressing part (71) abut against each other.

4. The intelligent assembly device for a nuclear fuel assembly grid according to claim 2, characterized in that, The detection unit includes: A force sensor is disposed on the drive structure and is used to detect the clamping force of the clamping structure. A displacement sensor is disposed on the drive structure and is used to detect the pressing displacement of the pressing structure.

5. The intelligent assembly device for a nuclear fuel assembly grid according to claim 4, characterized in that, The detection unit further includes an acoustic emission sensor. Each of the fixed blocks (6) is provided with an acoustic emission sensor on the side near the first strip (16). The acoustic emission sensor is used to collect acoustic emission parameters during the orthopedic process of the first strip (16).

6. The intelligent assembly device for a nuclear fuel assembly grid according to claim 2, characterized in that, The driving structure includes: A drive plate (10) is disposed at the bottom of the fixture body (2) and is fixedly connected to all the top posts (8); The first driving member is connected to the driving plate (10) and is used to drive the driving plate (10) to move the top column (8) in the mounting cavity (5).

7. The intelligent assembly device for a nuclear fuel assembly grid according to claim 1, characterized in that, Also includes: The mold frame (1) has a first space inside, and the clamp body (2) is disposed in the first space; and a grid tray (15) is also movably disposed in the first space, the grid tray (15) being used to push out the formed nuclear fuel assembly grid after assembly.

8. An intelligent assembly method for a nuclear fuel assembly grid, implemented using an intelligent assembly device for a nuclear fuel assembly grid as described in any one of claims 1-7, characterized in that, The method includes the following steps: The first strip is placed into the first channel in sequence, and multiple first strips form a first strip group; The control drive structure synchronously drives the clamping structure to apply a clamping force laterally to the corresponding first strip; During the orthopedic process, the orthopedic status parameters of the first strip group are determined based on the real-time compression parameters; The orthopedic state parameters include: initial warpage and material hardness; The compression control strategy database is queried. The compression control strategy database includes at least: multiple sets of first state parameters and a compression control strategy corresponding to each set of first state parameters; each set of first state parameters includes: an initial warpage range and a material hardness range. Traverse the clamping control strategy database, and when it is determined that the orthopedic state parameter matches any set of first state parameters, select the clamping control strategy corresponding to the first state parameter set, and control the drive structure to execute the clamping control strategy; Based on the real-time clamping parameters, the termination of the orthopedic process is controlled; The second strip is placed into the corresponding second channel in sequence, and interlocks with the first strip that has been straightened and fixed to form a nuclear fuel assembly grid.

9. The intelligent assembly method for a nuclear fuel assembly grid according to claim 8, characterized in that, The real-time clamping parameters include: clamping force, clamping displacement, and acoustic emission parameters; Based on the real-time clamping parameters, the termination of the orthopedic process is controlled, including the following steps: Collect the acoustic emission parameters, clamping force, and clamping displacement emitted by each acoustic emission sensor; Determine whether the acoustic emission parameters are less than a first threshold; If so, within multiple consecutive preset time windows, the slope of the platform area and the fluctuation of the clamping displacement are determined based on the clamping force and clamping displacement. Determine whether the slope of the platform area is less than the second threshold and whether the compression displacement fluctuation is less than the third threshold; If so, the orthopedic process is terminated.

10. The intelligent assembly method for a nuclear fuel assembly grid according to claim 9, characterized in that, It also includes the following steps: When the acoustic emission parameter is determined to be less than the first threshold, the orthopedic process is immediately terminated.

Images