Control rod single rod automatic mounting and dismounting device and control rod single rod dismounting method

Abstract

Embodiments of the present application provide a control rod single rod automatic mounting and dismounting device and a control rod single rod dismounting method, and relate to the field of nuclear reactor engineering and nuclear fuel manufacturing technology. The present application aims to improve the problem that the control rod assembly refueling and maintenance stay in the overall operation at the assembly level and lack the dismounting of single control rod. The guide hole is provided for the control rod to pass through to ensure the safety of hoisting, and the clamping and screwing mechanism is arranged in part of the guide hole to avoid the interference of the mechanism under the arrangement of multiple rods. The worn rod is aligned to the dismounting position hole in turn through hoisting and transposition, and the remaining rods do not participate in the operation, so that the single rod precise replacement is realized, and the whole set is avoided to be scrapped. The control unit accurately matches the screwing rotation speed and the lifting and translation speed according to the thread lead, so that the thread is naturally screwed in or out along the spiral line, and the thread damage in the finger tube is avoided. The base provides a universal mounting base, which can be flexibly deployed in various operation stations.

Description

Technical Field

[0001] This invention relates to the fields of nuclear reactor engineering and nuclear fuel manufacturing technology, and more specifically, to an automatic control rod installation and disassembly device and a control rod disassembly and assembly method. Background Technology

[0002] In large pressurized water reactor (PWR) nuclear power plants, control rod assemblies are critical safety components for reactor reactivity control and emergency shutdown. Taking a third-generation PWR nuclear power plant as an example, in the design of a third-generation PWR control rod assembly, a bundle of control rods typically contains more than twenty individual control rods (typically 24). The upper end of each control rod is connected to the finger tube of the connecting shank (also known as the star bracket) via threads. The entire assembly is driven by a control rod drive mechanism, moving up and down within the fuel assembly guide tube to achieve reactor start-up and shutdown, power regulation, and emergency shutdown. According to design specifications, the design service life of a control rod assembly is generally around 15 years. Throughout its lifespan, it needs to withstand numerous step movements, long-term water flow vibrations, and micro-motion contact with the guide tube. During long-term operation, the control rod cladding tube (usually a thin-walled tube made of stainless steel or nickel-based alloy) will exhibit two typical types of wear at specific locations: one is fretting wear caused by the vibration induced by the lateral flow of coolant within the guide tube; the other is sliding wear caused by the relative sliding between the cladding and the inner wall of the guide tube during the control rod's stepping motion. Both types of wear can cause localized thinning of the cladding tube wall, weakening its structural load-bearing capacity. When the cladding wear depth exceeds the allowable limit, and the control rod experiences a high number of stepping motions during its lifespan, the cladding is at risk of being worn through, leading to exposure of the internal neutron absorber and even fatigue fracture of the control rod. Once such excessive wear occurs, existing maintenance procedures typically require replacing the entire control rod assembly, and the operator must bear the associated safety risks, including primary circuit radioactive contamination and foreign object detachment from the absorber, if the cladding fails.

[0003] However, based on long-term operating experience of pressurized water reactor nuclear power plants both domestically and internationally, the wear of control rods exhibits a clear localized spatial distribution: wear is not evenly distributed across all 24 control rods, but rather concentrated at specific locations (usually on the periphery of the assembly or in areas heavily affected by flow-induced vibrations). Furthermore, in an assembly of 24 control rods, often only one or two rods show severe wear. In such cases, replacing the entire assembly would require disposing of a large number of still-fit control rods, along with their connecting handles, as radioactive waste. This not only significantly increases the operating costs and the amount of radioactive waste generated by the nuclear power plant but also contradicts the economic principles of the nuclear fuel cycle.

[0004] On the other hand, with the advancement of the important tasks of domestic research and development and independent innovation of large pressurized water reactor fuel assemblies and related components, the shortcomings caused by the insufficient automation of domestic control rod assembly production lines have become increasingly apparent. In the design of control rod assemblies, the control rods are connected to the connecting shank via threads. Taking into account the thread strength and various loads, the design specifies the installation torque for the control rods. The actual assembly process relies on manual operation. Although calibrated torque wrenches are used, the inherent errors of the tools themselves, coupled with individual differences in the angle and speed of force application by operators, result in significant fluctuations in the actual torque applied to the control rods. This uncertainty in torque values ​​increases the complexity of subsequent testing and the difficulty of quality control. Summary of the Invention

[0005] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form to prepare for the more detailed descriptions that follow.

[0006] The present invention aims to provide, for example, an automatic installation and removal device for a single control rod, which can improve the problem that control rod assembly replacement and maintenance are limited to the overall operation at the assembly level and lack the ability to install and remove individual control rods.

[0007] The embodiments of the present invention can be implemented as follows: An embodiment of the present invention provides an automatic installation and removal device for a single control rod, including a base, a perforated plate-shaped housing, a lifting drive mechanism, a control unit, and multiple sets of clamping and screwing mechanisms. The perforated plate-shaped housing is vertically movably disposed on the base, and has multiple guide holes spaced apart circumferentially. The guide holes are used to allow the single control rod to pass through and guide the single control rod when it is hoisted into position. The multiple sets of clamping and screwing mechanisms are respectively disposed at some of the guide holes, and the guide holes with the clamping and screwing mechanisms are disassembly / removal position holes. Each set of clamping and screwing mechanisms is used to clamp the single control rod that extends into the corresponding disassembly / removal position hole. The control rod is clamped and driven to rotate around its own axis. The lifting drive mechanism is disposed between the base and the perforated outer shell. The lifting drive mechanism is used to drive the perforated outer shell to move vertically relative to the base. The control unit is signal-connected to the clamping and screwing mechanism and the lifting drive mechanism. The control unit is used to control the lifting drive mechanism to drive the perforated outer shell to drive the multiple sets of clamping and screwing mechanisms to synchronously translate along the axial direction of the control rod while the clamping and screwing mechanism drives the control rod to rotate. This is done according to the thread lead between the control rod and the connecting handle.

[0008] In addition, the control rod single-rod automatic installation and disassembly device provided in the embodiments of the present invention may also have the following additional technical features: Optionally, among the plurality of guide holes, the remaining guide holes other than the disassembly / assembly position holes are non-disassembly / assembly position holes. The clamping and screwing mechanism is not provided at the non-disassembly / assembly position holes. The non-disassembly / assembly position holes are used for the control rods not in the disassembly / assembly position to pass through and be radially guided. The number of disassembly / assembly position holes is less than the total number of guide holes. The plurality of disassembly / assembly position holes are evenly spaced circumferentially along the central vertical axis of the perforated shell. The circumferential spacing angle between the disassembly / assembly position holes matches the circumferential symmetrical arrangement angle of the control rods on the control rod assembly. This allows the control rods located at different radii to be aligned with the disassembly / assembly position holes in sequence when the control rod assembly rotates around the central vertical axis to different angular positions.

[0009] Optionally, each set of clamping and screwing mechanisms includes a clamping mechanism and a screwing mechanism. The clamping mechanism is used to clamp the control rod to be disassembled and assembled. The screwing mechanism includes a rotary actuator that contacts and engages with the outer circumferential surface of the control rod. The rotary actuator is used to drive the control rod to rotate around its own axis through contact transmission when the clamping mechanism clamps the control rod.

[0010] Optionally, the rotating actuator of the turning mechanism is a turning roller; the turning mechanism further includes a turning drive motor and a transmission assembly connected in sequence, the power output shaft of the turning drive motor is arranged along the radial direction of the control rod, the outer circumferential surface of the turning roller is in contact with the outer circumferential surface of the control rod, the output end of the transmission assembly is connected to the turning roller, and the transmission assembly is used to convert the rotational output of the turning drive motor about its own axis into the rotation of the turning roller about its own axis, and the turning roller drives the control rod to rotate about its own axis through friction.

[0011] Optionally, the rotary drive motor is a miniature radiation-resistant servo motor; the transmission component is a hypoid gear set or a bevel gear set, the driving wheel of the hypoid gear set or bevel gear set is mounted on the power output shaft of the rotary drive motor, and the driven wheel is coaxially fixed with the rotary roller and meshes with the driving wheel.

[0012] Optionally, the clamping mechanism includes at least two clamping rollers. The turning roller and the at least two clamping rollers are circumferentially distributed on the outer periphery of the control rod in the corresponding disassembly and assembly holes. When the turning roller is in contact with the control rod, it drives the control rod to rotate through friction. The at least two clamping rollers follow the rotation of the control rod to form multi-point clamping and radial guidance for the control rod together with the turning roller.

[0013] Optionally, the clamping mechanism further includes a clamping drive assembly, a linkage mechanism, and an upper and lower perforated plate disposed opposite to each other. The upper and lower perforated plates have through holes corresponding to the disassembly / assembly position holes. The through holes are used for a single control rod passing through the disassembly / assembly position holes. The clamping drive assembly connects the upper and lower perforated plates and is used to adjust the vertical distance between the upper and lower perforated plates. The upper and lower perforated plates are respectively connected to the at least two clamping rollers via the linkage mechanism. When the clamping drive assembly drives the adjustment of the vertical distance between the upper and lower perforated plates, the linkage mechanism drives the at least two clamping rollers to move radially to clamp or release the single control rod.

[0014] Optionally, the clamping drive assembly includes a clamping servo motor and a ball screw drive pair connected by a transmission. The ball screw drive pair is connected to the upper hole plate and the lower hole plate. The clamping servo motor drives at least one of the upper hole plate and the lower hole plate to move axially through the ball screw drive pair, so as to adjust the vertical distance between the upper hole plate and the lower hole plate.

[0015] Optionally, each set of clamping and screwing mechanisms includes a miniature direct-drive torque motor and a miniature pneumatic chuck or miniature electric chuck integrated at the end of the miniature direct-drive torque motor. The hollow shaft of the miniature direct-drive torque motor is coaxially arranged with the corresponding guide hole. The miniature direct-drive torque motor is used to directly drive the chuck to rotate to output screwing torque to the control rod. The jaws of the miniature pneumatic chuck or miniature electric chuck are used to clamp the control rod from the outer periphery of the control rod and rotate synchronously with the hollow shaft of the miniature direct-drive torque motor.

[0016] Optionally, each set of clamping and screwing mechanisms further includes an optical fiber slip ring, which is coaxially mounted at the tail of the hollow shaft of the miniature direct-drive torque motor. The optical fiber slip ring is signal-connected to the miniature pneumatic chuck or miniature electric chuck and is used to transmit the motion control signal of the miniature pneumatic chuck or miniature electric chuck in a strong irradiation environment.

[0017] Optionally, the lifting drive mechanism includes a base servo motor and a base ball screw transmission pair mounted on the base and connected in a transmission relationship. The base ball screw transmission pair is connected to the perforated outer shell. The base servo motor drives the base ball screw transmission pair to rotate, thereby driving the perforated outer shell to translate vertically as a whole.

[0018] Optionally, each set of clamping and turning mechanisms is further equipped with a torque sensor and / or a pressure sensor: the torque sensor is integrated into the turning power output path and is used to detect the actual turning torque applied to the single control rod in real time; the pressure sensor is set in the clamping force transmission path and is used to detect the actual clamping force applied to the outer circumferential surface of the single control rod in real time; the control unit is connected to the torque sensor and the pressure sensor, and the control unit is used to perform closed-loop control of the clamping force according to the feedback signal of the pressure sensor, and to start the turning action of the clamping and turning mechanism after the clamping force reaches the set value; the control unit is also used to perform closed-loop control of the turning torque according to the feedback signal of the torque sensor.

[0019] Optionally, during installation, when the actual turning torque detected by the torque sensor reaches the preset installation torque value, the control unit controls the clamping and turning mechanism to stop turning and maintain the current torque, while recording and storing the actual output torque data and the corresponding rod position number.

[0020] Embodiments of the present invention also provide a method for assembling and disassembling a single control rod, implemented using an automatic single-rod installation and disassembly device for the control rod, comprising: The automatic control rod installation and removal device is fixedly installed above the temporary storage rack for control rod assemblies or above the workstation support of the fuel assembly production line. The control rod assembly is hoisted to the underside of the automatic control rod installation and removal device using hoisting equipment. The control rod is guided through the guide holes on the perforated outer shell, aligning the control rod to be installed with the corresponding installation / removal hole equipped with the clamping and screwing mechanism. The clamping and screwing mechanism is controlled to clamp the corresponding control rod. Simultaneously, the clamping and screwing mechanism and the lifting drive mechanism are activated: the clamping and screwing mechanism drives the clamped control rod to rotate around its own axis, and the lifting drive mechanism drives the perforated outer shell and the clamping and screwing mechanism to translate axially along the control rod. The control unit controls the ratio of the vertical translation speed to the screwing speed to match the thread lead between the control rod and the connecting handle. After the thread of the control rod is fully screwed into or out of the connecting handle of the control rod assembly, the clamping and screwing mechanism and the lifting drive mechanism are stopped. The clamping and screwing mechanism is then controlled to release the control rod at the corresponding position.

[0021] Optionally, the method for disassembling and assembling a single control rod further includes: the disassembly and assembly holes are evenly spaced circumferentially along the central vertical axis of the perforated shell; after the disassembly and assembly of a single control rod at the current position is completed, the control rod assembly is vertically lifted by a hoisting device until the lower end of the single control rod is disengaged from the guide hole; the assembly is rotated around the central vertical axis of the perforated shell by a preset angle equal to the circumferential interval angle between the disassembly and assembly holes, so that a group of single control rods to be disassembled and assembled at the next radius position are aligned with the disassembly and assembly holes; then the control rod assembly is lowered so that the single control rods to be disassembled and assembled pass through the corresponding disassembly and assembly holes; the clamping, twisting, and lifting synchronous actions are repeated until all the single control rods to be disassembled and assembled on the control rod assembly are replaced or assembled.

[0022] The beneficial effects of the automatic installation and disassembly device and method for single control rod assembly / disassembly of the present invention include, for example: The control rod automatic installation and disassembly device features guide holes through which the control rods pass to ensure lifting safety. However, clamping and tightening mechanisms are only installed in some guide holes. This avoids spatial interference between adjacent mechanisms in the compact arrangement of 24 rods, and allows only 1-2 worn rods requiring replacement to be aligned with the disassembly / removal positions during lifting and repositioning. The remaining rods do not participate in the operation, achieving precise replacement of each rod and preventing the entire unit from being scrapped. The control unit precisely matches the tightening speed with the lifting and translation speed based on the thread lead, allowing the thread to naturally screw in or out along its own helix, avoiding damage such as stripping or cross-threading of the internal threads of the finger tube. The base provides a universal installation foundation for different working conditions, enabling the device to be flexibly deployed in various work positions.

[0023] The control rod single-rod assembly and disassembly method adopts the above-mentioned automatic installation and disassembly device for control rods. The screwing and lifting leads are synchronized to avoid thread damage. The torque closed-loop control enables traceability of tightening quality. The hoisting and repositioning simplifies the structure. It can improve the problem that the replacement and maintenance of control rod components are limited to the overall operation at the component level, and lacks the ability to disassemble and assemble individual control rods. Attached Figure Description

[0024] The above-described features and advantages of the present invention will be better understood after reading the following detailed description of embodiments of the present disclosure in conjunction with the accompanying drawings. In the drawings, components are not necessarily drawn to scale, and components having similar related characteristics or features may have the same or similar reference numerals.

[0025] Figure 1 A schematic diagram of the structure of the automatic installation and disassembly device for a single control rod provided in an embodiment of the present invention, installed on a temporary storage rack for control rod assemblies or a workstation support on a fuel assembly production line; Figure 2 A top view of the perforated plate-shaped housing of the control rod single-rod automatic installation and disassembly device provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the clamping and screwing mechanism of the automatic installation and disassembly device for a single control rod provided in an embodiment of the present invention. Figure 4 A schematic diagram of the structure of a miniature direct-drive torque motor for an automatic installation and disassembly device for a single control rod provided in an embodiment of the present invention.

[0026] Icons: Control rod single-rod automatic installation and removal device - 101; Base - 110; Perforated plate housing - 120; Guide hole - 121; Removal hole - 121a; Non-removal hole - 121b; Clamping and turning mechanism - 130; Clamping mechanism - 131; Turning mechanism - 132; Lifting drive mechanism - 140; Base ball screw transmission pair - 142; Control unit - 150; Torque sensor - 151; Pressure sensor - 152; Single control rod - 160; Control rod assembly - 170; Connecting handle - 171; Finger tube - 172; Turning roller - 210; Mounting plate - 2 11; Through hole - 212; Twisting drive motor - 220; Transmission assembly - 230; Drive wheel - 231; Driven wheel - 232; Clamping roller - 240; Upper hole plate - 250; Lower hole plate - 260; Through hole - 261; Linkage mechanism - 270; Clamping drive assembly - 280; Clamping ball screw transmission pair - 282; Miniature through direct drive torque motor - 310; Hollow shaft - 312; Miniature pneumatic chuck or miniature electric chuck - 320; Claw - 321; Temporary storage rack for control rod assembly - 410; Fuel assembly production line station bracket - 420; Fiber optic slip ring - 330. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be noted that the aspects described below with reference to the accompanying drawings and specific embodiments are merely exemplary and should not be construed as limiting the scope of protection of the present invention in any way.

[0028] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," "outer," or "vertical" appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed when in use, and does 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, and therefore should not be construed as a limitation of this invention.

[0029] At the same time, it should be noted that the terms "first" and "second" are used only for distinguishing descriptions and should not be interpreted as indicating or implying relative importance.

[0030] In the description of this invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an integral connection, or a detachable connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or a connection within two components, etc. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0031] In existing technologies, control rods can only be replaced as a whole when they wear out, but actual wear often only involves 1-2 out of 24 rods, resulting in huge maintenance waste from replacing the entire set. Furthermore, the assembly process relies on manual torque wrenches, and the inherent errors of the tools, combined with individual differences in the operator's force application angle and speed, lead to significant fluctuations in actual torque and a high risk of thread damage. In addition, manual intervention in the high-irradiation environment of spent fuel pools poses personnel safety risks.

[0032] The following is combined Figures 1 to 4 The automatic single-bar installation and removal device 101 for control rods provided in this embodiment will be described in detail. The automatic single-bar installation and removal device 101 for control rods achieves digital controllability of the torque for single-bar replacement and assembly by integrating clamping and turning mechanisms, using servo closed-loop precise torque control, and synchronous linkage between turning and lifting leads. It also supports remote automated operation, thus improving the aforementioned problems.

[0033] Please refer to Figure 1 , Figure 2 and Figure 3An embodiment of the present invention provides an automatic installation and removal device 101 for a single control rod, including a base 110, a perforated outer shell 120, a lifting drive mechanism 140, a control unit 150, and multiple clamping and screwing mechanisms 130. The perforated outer shell 120 is vertically movably disposed on the base 110. The perforated outer shell 120 is provided with multiple guide holes 121 spaced apart circumferentially. The guide holes 121 are used to allow the single control rod 160 to pass through and guide the single control rod 160 when the control rod assembly 170 is hoisted into place. The multiple clamping and screwing mechanisms 130 are respectively disposed at some of the guide holes 121. The guide holes 121 with clamping and screwing mechanisms 130 are disassembly and assembly position holes 121a. Each clamping and screwing mechanism 130 is used to clamp the corresponding disassembly and assembly position hole. The control rod 160 of hole 121a is clamped and driven to rotate around its own axis; the lifting drive mechanism 140 is disposed between the base 110 and the perforated shell 120, and the lifting drive mechanism 140 is used to drive the perforated shell 120 to move vertically relative to the base 110; the control unit 150 is signal connected to the clamping and turning mechanism 130 and the lifting drive mechanism 140, and the control unit 150 is used to control the lifting drive mechanism 140 to drive the perforated shell 120 to drive multiple sets of clamping and turning mechanisms 130 to synchronously translate along the axial direction of the control rod 160 while the clamping and turning mechanism 130 drives the control rod 160 to rotate, so that the turning motion is synchronized with the lead of the axial translation.

[0034] The base 110 serves as the fixed base for the entire device, made of stainless steel or nickel-based alloy. In nuclear power plant spent fuel pool applications, it is fixedly installed on the upper end of the control rod assembly temporary storage rack 410; in fuel assembly production line applications, it is fixedly installed on the upper end of the production line workstation support. In nuclear power plant spent fuel pool applications, the automatic control rod single-rod installation and removal device 101 can be installed together with automated cutting tools and automated welding tools at the operating station above the control rod assembly temporary storage rack 410. The actions of each tool are coordinated by a remote control console to sequentially complete the cutting, removal, new rod installation, and welding sealing operations of the damaged control rod 160. The base 110 is provided with installation interfaces (such as bolt holes and locating pin holes) to connect with mating features on the storage rack or workstation support, ensuring that the device does not shift relative to the workstation during operation. The base 110 provides a stable support reference for the perforated plate-shaped housing 120 and all the clamping and tightening mechanisms 130 on it, bearing the tightening reaction torque, clamping reaction force, and lifting load; it also serves as the installation platform for the lifting drive mechanism 140.

[0035] The perforated housing 120 is vertically movably mounted above the base 110, supported by the lifting drive mechanism 140, and slides vertically with the base 110. The perforated housing 120 has multiple guide holes 121 distributed horizontally circumferentially. Each guide hole 121 extends vertically through the thickness of the perforated housing 120, and its diameter is slightly larger than the outer diameter of the control rod 160. When the control rod assembly 170 is hoisted into position by the hoisting equipment, the control rod 160 passes vertically through the corresponding guide hole 121 from above. The inner wall of the guide hole 121 radially constrains the control rod 160, preventing it from tilting during hoisting and lowering, and aligning it with the corresponding clamping and tightening mechanism 130 below.

[0036] Of the multiple guide holes 121, the guide hole 121 equipped with a clamping and tightening mechanism 130 is the disassembly / assembly position hole 121a, and the guide hole 121 without the clamping and tightening mechanism 130 is the non-disassembly / assembly position hole 121b. The disassembly / assembly position hole 121a is equipped with a complete clamping and tightening mechanism 130, which can perform clamping, tightening, and loosening actions on the control rod 160 passing through the hole. The non-disassembly / assembly position hole 121b only provides a guiding function, allowing the control rod 160 not in the disassembly / assembly position to pass through, and does not perform any clamping or tightening actions.

[0037] Each clamping and screwing mechanism 130 integrates the clamping and screwing actions into the same disassembly and assembly hole 121a. The coaxial arrangement of clamping and screwing ensures that the rotational torque is applied along the axis of the control rod 160, without generating an eccentric bending moment, thus protecting the internal threads of the thin-walled shell tube and the finger tube 172.

[0038] A lifting drive mechanism 140 is disposed between the base 110 and the perforated housing 120, and is used to drive the perforated housing 120 to move vertically relative to the base 110. The fixed end of the lifting drive mechanism 140 is connected to the base 110, and the motion output end is connected to the perforated housing 120.

[0039] The control unit 150 is signal-connected to the drive elements in the clamping and screwing mechanism 130 and the lifting drive mechanism 140. While the clamping and screwing mechanism 130 drives the control rod 160 to rotate, it controls the lifting drive mechanism 140 to drive the perforated housing 120, causing multiple sets of clamping and screwing mechanisms 130 to synchronously translate along the axial direction of the control rod 160, ensuring that the screwing motion and the axial translation lead are synchronized. Specifically, the control unit 150 controls the screwing speed n (in r / min) and the vertical translation speed v (in mm / s) of the perforated housing 120 to satisfy v = n·P / 60, where P is the lead (in mm) of the threaded connection between the control rod 160 and the connecting handle 171. Each rotation of the thread moves one lead P axially; therefore, the axial speed corresponding to the speed n (r / min = r / 60s) is n·P / 60 (mm / s).

[0040] Reference Figure 1 , Figure 2 and Figure 3 In this embodiment, among the multiple guide holes 121, the guide holes 121 other than the disassembly and assembly position holes 121a are non-disassembly and assembly position holes 121b. No clamping and screwing mechanism 130 is provided at the non-disassembly and assembly position holes 121b. The non-disassembly and assembly position holes 121b are used for the control rod 160 that is not in the disassembly and assembly position to pass through and be radially guided. The number of disassembly and assembly position holes 121a is less than the total number of guide holes 121. The multiple disassembly and assembly position holes 121a are evenly distributed circumferentially along the central vertical axis of the perforated shell 120, and the circumferential interval angle between the disassembly and assembly position holes 121a matches the circumferential symmetrical arrangement angle of the control rod 160 on the control rod assembly 170. This allows the control rod 160 located at different radii to be aligned with the disassembly and assembly position holes 121a in sequence when the control rod assembly 170 rotates around the central vertical axis to different angle positions.

[0041] As previously stated, the multiple guide holes 121 on the perforated housing 120 are divided into two categories: disassembly / removal position holes 121a and non-disassembly / removal position holes 121b. In a preferred embodiment, taking the control rod assembly 170 comprising 24 control rods 160 as an example, the total number of guide holes 121 is the same as the number of control rods 160, that is, the 24 guide holes 121 are evenly distributed along the circumferential direction on the perforated housing 120. Among them, some guide holes 121 (e.g., 6) are set as disassembly / removal position holes 121a, and clamping and tightening mechanisms 130 are installed at these 6 disassembly / removal position holes 121a respectively; the remaining 18 guide holes 121 are non-disassembly / removal position holes 121b, without clamping and tightening mechanisms 130, and only serve as guide holes for the control rods 160 to pass through. When the control rod assembly 170 is hoisted above the perforated housing 120 by the hoisting equipment, the 24 control rods 160 pass vertically through the 24 guide holes 121 respectively. At this time, the six control rods 160 passing through the six disassembly / assembly holes 121a are aligned with the clamping and tightening mechanism 130 and can perform clamping and tightening operations; while the control rods 160 passing through the 18 non-disassembly / assembly holes 121b are only in the passing state and do not perform any operations. The control rod assembly 170 includes more than twenty control rods 160, and each control rod 160 is arranged on the connecting handle 171 with a compact pitch; if the clamping and tightening mechanism 130 is provided at all the guide holes 121, the drive elements of adjacent mechanisms will have spatial interference in the radial direction. In this embodiment, the clamping and tightening mechanism 130 is provided only at some of the guide holes 121, i.e., the disassembly / assembly holes 121a, and there is at least one non-disassembly / assembly hole 121b between adjacent disassembly / assembly holes 121a, so as to reserve sufficient installation space for the drive elements and transmission components of the clamping and tightening mechanism 130, and allow the device to be reasonably arranged within the limited area of ​​the perforated plate.

[0042] After the current six control rods 160 are disassembled and installed, the control rod assembly 170 is lifted vertically using hoisting equipment. Then, it is rotated horizontally around the vertical axis by a preset angle, aligning the next control rod 160 or group to be disassembled with the disassembly / installation hole 121a. The control rod assembly 170 is then lowered so that the target control rod 160 is inserted into the corresponding disassembly / installation hole 121a. By repeatedly adjusting the hoisting position of the control rod assembly 170, the control rods 160 in different positions can be aligned sequentially with the disassembly / installation holes 121a, completing the installation or disassembly of all 24 control rods 160 one by one or group by group.

[0043] Reference Figure 1 and Figure 3In this embodiment, each clamping and screwing mechanism 130 includes a clamping mechanism 131 and a screwing mechanism 132. The clamping mechanism 131 is used to clamp the control rod 160 to be disassembled and assembled. The screwing mechanism 132 includes a rotating actuator that contacts and cooperates with the outer circumferential surface of the control rod 160. The rotating actuator is used to drive the control rod 160 to rotate around its own axis through contact transmission when the clamping mechanism 131 clamps the control rod 160.

[0044] The clamping mechanism 131 and the screwing mechanism 132 are coaxially arranged along the axis of the disassembly / assembly hole 121a and cooperate in the radial direction. At least two clamping actuators (clamping rollers 240 or chucks 321) are arranged in the circumferential direction of the clamping mechanism 131 along the disassembly / assembly hole 121a. These clamping actuators can move radially along the disassembly / assembly hole 121a. When the control rod 160 passes through the disassembly / assembly hole 121a and reaches the set axial position, the clamping actuators move radially inward to abut against the outer circumferential surface of the control rod 160, applying positive pressure to fix it radially. The clamping mechanism 131 is responsible for radially fixing the control rod 160, while the screwing mechanism 132 is responsible for applying circumferential rotational torque. The rotation actuators contact the outer circumferential surface of the control rod 160 for transmission, eliminating the need to machine a dedicated transmission structure on the rod body. The rotating actuator of the turning mechanism 132 transmits the turning torque through contact transmission (friction) between its outer circumferential surface and the outer circumferential surface of the control rod 160, eliminating the need to machine keyways, flat surfaces, hexagonal heads, or other specialized transmission structures onto the control rod 160. The casing tube of the control rod 160 is a thin-walled tube with a smooth cylindrical outer circumferential surface, making it impossible to machine any grooves or planar features on its surface. Therefore, the contact transmission method is irreplaceable.

[0045] Reference Figure 3 In this embodiment, the rotating actuator of the rotating mechanism 132 is a rotating roller 210; the rotating mechanism 132 also includes a rotating drive motor 220 and a transmission assembly 230 connected in sequence. The power output shaft of the rotating drive motor 220 is arranged along the radial direction of the control rod 160. The outer circumferential surface of the rotating roller 210 is in contact with the outer circumferential surface of the control rod 160. The output end of the transmission assembly 230 is connected to the rotating roller 210. The transmission assembly 230 is used to convert the rotational output of the rotating drive motor 220 around its own axis into the rotation of the rotating roller 210 around its own axis. The rotating roller 210 drives the control rod 160 to rotate around its own axis through friction.

[0046] The outer circumference of the turning roller 210 is covered with a friction material layer, making direct contact with the outer circumferential surface of the control rod 160. The turning drive motor 220 is a miniature radiation-resistant servo motor, with its power output shaft arranged radially along the control rod 160. This radial arrangement allows the motor body to be embedded between adjacent guide holes 121, resolving spatial conflicts of the control rod. The roller friction transmission protects the thin-walled shell surface. The radiation-resistant servo motor ensures that the torque output does not attenuate under high radiation environments, meeting the reliability requirements for continuous operation of the spent fuel pool.

[0047] In this embodiment, the screwing mechanism 132 further includes a mounting plate 211, which is fixed inside the perforated outer shell 120. The mounting plate 211 is also provided with a through hole 212 corresponding to the disassembly / assembly hole 121a. The through hole 212 is used for the control rod 160 to pass through the disassembly / assembly hole 121a. The disassembly / assembly hole 121a, the through hole 261 of the upper perforated plate 250 and the lower perforated plate 260, and the through hole 212 of the mounting plate 211 are coaxially arranged to allow the control rod 160 to be disassembled / assembled to pass through. The screwing roller 210 is rotatably mounted on the mounting plate 211.

[0048] Reference Figure 3 In this embodiment, the rotary drive motor 220 is a miniature radiation-resistant servo motor; the transmission assembly 230 is a hypoid gear set or a bevel gear set. The driving wheel 231 of the hypoid gear set or bevel gear set is mounted on the power output shaft of the rotary drive motor 220, and the driven wheel 232 is coaxially fixed with the rotary roller 210 and meshes with the driving wheel 231. The transmission assembly 230 uses a hypoid gear set or a bevel gear set to transmit the motor output to the rotary roller 210 after a 90° reversal.

[0049] Reference Figure 3 In this embodiment, the clamping mechanism 131 includes at least two clamping rollers 240. The rotating roller 210 and the at least two clamping rollers 240 are distributed circumferentially on the outer periphery of the control rod 160 in the corresponding disassembly and assembly hole 121a. When the rotating roller 210 is in contact with the control rod 160, it drives the control rod 160 to rotate by friction. The at least two clamping rollers 240 follow the rotation of the control rod 160 to form multi-point clamping and radial guidance of the control rod 160 together with the rotating roller 210.

[0050] The clamping roller 240 rotates to create pure rolling contact rather than sliding friction, thus preventing damage to the casing surface. The turning roller 210 has both clamping and torque transmission functions, reducing the number of parts and the radial envelope size.

[0051] Reference Figure 3In this embodiment, the clamping mechanism 131 further includes a clamping drive assembly 280, a linkage mechanism 270, and an upper hole plate 250 and a lower hole plate 260 disposed opposite to each other. The upper hole plate 250 and the lower hole plate 260 are provided with through holes 261 corresponding to the disassembly and assembly position hole 121a. The through holes 261 are used for the control rod 160 passing through the disassembly and assembly position hole 121a. The clamping drive assembly 280 is connected to the upper hole plate 250 and the lower hole plate 260 and is used to adjust the vertical distance between the upper hole plate 250 and the lower hole plate 260. The upper hole plate 250 and the lower hole plate 260 are respectively connected to at least two clamping rollers 240 through the linkage mechanism 270. When the clamping drive assembly 280 drives the adjustment of the vertical distance between the upper hole plate 250 and the lower hole plate 260, the linkage mechanism 270 drives at least two clamping rollers 240 to move radially to clamp or release the control rod 160.

[0052] The upper perforated plate 250 and lower perforated plate 260 are plates independently of the perforated plate-shaped housing 120, located inside the housing 120. They have through holes 261 corresponding to the mounting / unmounting holes 121a. Vertical spacing adjustment is achieved by the clamping drive assembly 280, while the housing 120 remains stationary. The linkage mechanism 270 achieves a large radial clamping stroke with a small axial stroke, resulting in a compact structure. The linkage mechanism 270 converts the axial relative displacement between the upper perforated plate 250 and lower perforated plate 260 into the radial clamping stroke of the clamping roller 240. Through the lever amplification effect, the clamping servo motor achieves the required radial clamping stroke with a small axial drive stroke, resulting in a compact structure and rapid response. The servo motor, in conjunction with the ball screw, enables precise adjustment of the clamping force and rapid response.

[0053] Reference Figure 3 In this embodiment, the clamping drive assembly 280 includes a clamping servo motor and a ball screw drive pair connected by transmission. The ball screw drive pair is connected to the upper hole plate 250 and the lower hole plate 260. The clamping servo motor drives at least one of the upper hole plate 250 and the lower hole plate 260 to move axially through the ball screw drive pair, so as to adjust the vertical distance between the upper hole plate 250 and the lower hole plate 260.

[0054] The ball screw drive pair is threadedly connected to the upper hole plate 250 and / or the lower hole plate 260. The rotation of the ball screw drive pair drives the upper hole plate 250 and the lower hole plate 260 to move up and down along the axial direction of the ball screw drive pair.

[0055] Reference Figure 4In this embodiment, each clamping and twisting mechanism 130 includes a miniature direct-drive torque motor 310 and a miniature pneumatic chuck or miniature electric chuck 320 integrated at the end of the miniature direct-drive torque motor 310. The hollow shaft 312 of the miniature direct-drive torque motor 310 is coaxially arranged with the corresponding guide hole 121. The miniature direct-drive torque motor 310 is used to directly drive the chuck to rotate to output twisting torque to the control rod 160. The jaws 321 of the miniature pneumatic chuck or miniature electric chuck 320 are used to clamp the control rod 160 from the outer periphery and rotate synchronously with the hollow shaft 312 of the miniature direct-drive torque motor 310.

[0056] In this embodiment, each clamping and screwing mechanism also includes an optical fiber slip ring 330. The optical fiber slip ring 330 is coaxially mounted on the tail of the hollow shaft 312 of the miniature direct drive torque motor 310. The optical fiber slip ring 330 is signal connected to the miniature pneumatic chuck or miniature electric chuck 320 and is used to transmit the action control signal of the miniature pneumatic chuck or miniature electric chuck 320 in a strong irradiation environment.

[0057] In the second embodiment, each clamping and screwing mechanism 130 includes a miniature direct-drive torque motor 310 and a miniature pneumatic chuck or miniature electric chuck integrated at the motor end. The hollow shaft 312 of the direct-drive rotary (DDR) motor is coaxial with the guide hole 121, directly driving the chuck to rotate and output screwing torque. The chuck jaws 321 clamp from the outer periphery of the control rod 160 and rotate synchronously with the hollow shaft 312. In strong radiation environments, the chuck action signal is transmitted by the fiber optic slip ring 330. DDR direct drive eliminates gear transmission backlash and return error, resulting in high torque accuracy. The three-jaw chuck automatically aligns to ensure coaxiality. The hollow structure allows the control rod to pass through, resulting in a compact axial dimension. The pneumatic chuck is suitable for underwater operations, and the fiber optic slip ring 330 replaces the conductive slip ring to avoid radiation degradation. The fiber optic slip ring 330 is coaxially mounted at the tail of the hollow shaft 312 without increasing the radial dimension of the device. It also has a high degree of rotational coaxiality with the hollow shaft 312, ensuring stable signal transmission. The two configurations are complementary in their applicable scenarios.

[0058] Reference Figure 1 In this embodiment, the lifting drive mechanism 140 includes a base servo motor and a base ball screw transmission pair 142 disposed on the base 110 and connected in transmission. The base ball screw transmission pair 142 is connected to the perforated outer shell 120. The base servo motor drives the base ball screw transmission pair 142 to rotate, thereby driving the perforated outer shell 120 to move vertically as a whole.

[0059] The base servo motor, in conjunction with the ball screw, provides high positioning accuracy, meeting the requirements for fine thread feed. A lifting drive mechanism 140 synchronously feeds the perforated housing 120 and all clamping and tightening mechanisms 130, simplifying multi-axis coordinated control.

[0060] Reference Figure 1 and Figure 3 In this embodiment, each clamping and twisting mechanism 130 is further provided with a torque sensor 151 and / or a pressure sensor 152: the torque sensor 151 is integrated on the twisting power output path and is used to detect the actual twisting torque applied to the control rod 160 in real time; the pressure sensor 152 is set on the clamping force transmission path and is used to detect the actual clamping force applied to the outer circumferential surface of the control rod 160 in real time; the control unit 150 is signal-connected to the torque sensor 151 and the pressure sensor 152, and the control unit 150 is used to perform closed-loop control of the clamping force according to the feedback signal of the pressure sensor 152, and to start the twisting action of the clamping and twisting mechanism 130 after the clamping force reaches the set value; the control unit 150 is also used to perform closed-loop control of the twisting torque according to the feedback signal of the torque sensor 151.

[0061] In the roller linkage embodiment, the torque sensor 151 is mounted on the axle of the turning roller 210, or integrated into the rotor position of the turning drive motor 220. In the integrated chuck embodiment, the torque sensor 151 is mounted on the hollow shaft 312 of the miniature direct-drive torque motor 310. In the roller linkage embodiment, the pressure sensor 152 is a miniature pressure sensor 152, attached to the force-bearing segment of the linkage mechanism 270. In the integrated chuck embodiment, the pressure sensors 152 are respectively attached to the base of the chuck jaws 321. During the clamping phase, the control unit 150 monitors the clamping force signal fed back by the pressure sensor 152 and allows the tightening to start only after the clamping force reaches the set value. During the tightening phase, the control unit 150 monitors the tightening torque signal fed back by the torque sensor 151 in real time. When installing a new control rod 160, the control unit 150 immediately controls the tightening mechanism 132 to stop and maintain the torque when the actual tightening torque reaches the preset installation torque value. When disassembling a damaged control rod 160, the control unit monitors whether there is an abnormal sudden increase in torque. If there is an abnormality, the control unit immediately stops the machine and alarms.

[0062] In this embodiment, during installation, when the actual turning torque detected by the torque sensor 151 reaches the preset installation torque value, the control unit 150 controls the clamping and turning mechanism 130 to stop turning and maintain the current torque, while recording and storing the actual output torque data and the corresponding rod position number.

[0063] In this embodiment, the inventors noted that when disassembling a damaged control rod 160 that has been in long-term service in a spent fuel pool, the internal threads of the connecting handle 171 finger tube 172 may become stuck due to irradiation aging, accumulation of corrosion products, or wear deformation. If the normal lead is still used for synchronous screwing, it may cause further damage to the threads or even break the control rod 160. Therefore, during disassembly, the control unit 150 monitors the actual screwing torque fed back by the torque sensor 151 in real time during the screwing process of the clamping and screwing mechanism 130. When the actual screwing torque shows an abnormal sudden increase, the control unit immediately controls the clamping and screwing mechanism 130 and the lifting drive mechanism 140 to stop and issue an alarm signal.

[0064] Reference Figure 1 , Figure 2 and Figure 3 The embodiments of the present invention also provide a method for disassembling and assembling a single control rod, implemented using an automatic single-rod installation and disassembly device 101, comprising: Step S1: Fix the control rod single rod automatic installation and removal device 101 above the control rod assembly temporary storage rack 410 or above the fuel assembly production line station bracket 420. Step S2: The control rod assembly 170 is hoisted to the bottom of the control rod single rod automatic installation and disassembly device 101 by the hoisting equipment. The control rod 160 is guided by the guide hole 121 on the perforated housing 120 so that the control rod 160 to be disassembled is aligned with the disassembly and assembly position hole 121a of the clamping and screwing mechanism 130. Step S3: Control the clamping and screwing mechanism 130 to clamp the corresponding control bar 160; Step S4: Simultaneously activate the clamping and screwing mechanism 130 and the lifting drive mechanism 140: The clamping and screwing mechanism 130 drives the clamped control rod 160 to rotate around its own axis, and the lifting drive mechanism 140 drives the perforated housing 120 and the clamping and screwing mechanism 130 to translate along the axial direction of the control rod 160. The control unit 150 controls the speed ratio between the vertical translation speed and the screwing speed to match the thread lead between the control rod 160 and the connecting handle 171. Step S5: After the thread of the control rod 160 is fully screwed into or out of the connecting handle 171 of the control rod assembly 170, stop the clamping and turning mechanism 130 and the lifting drive mechanism 140; in other embodiments, record the actual output torque data of the current turning action.

[0065] Step S6: Control the clamping and screwing mechanism 130 to release the control rod 160 at the corresponding rod position.

[0066] In the application scenario of spent fuel pool in nuclear power plants, the base 110 is connected to the installation interface at the upper end of the storage rack by bolts or quick-locking mechanism, and the entire device is submerged in the pool water; in the application scenario of fuel assembly production line, the base 110 is fixed above the workstation support of the production line.

[0067] Reference Figure 1 , Figure 2 and Figure 3 In this embodiment, the method for disassembling and assembling a single control rod further includes: disassembly and assembly holes 121a are evenly spaced circumferentially along the central vertical axis of the perforated housing 120. After the disassembly and assembly of the single control rod 160 at the current position is completed, the control rod assembly 170 is vertically lifted by a hoisting device until the lower end of the single control rod 160 is disengaged from the guide hole 121. The assembly is then rotated around the central vertical axis of the perforated housing 120 by a preset angle equal to the circumferential interval angle between the disassembly and assembly holes 121a, so that a group of single control rods 160 to be disassembled and assembled at the next radius position are aligned with the disassembly and assembly holes 121a. The control rod assembly 170 is then lowered so that the single control rods 160 to be disassembled and assembled pass through the corresponding disassembly and assembly holes 121a. The clamping, twisting, and lifting synchronous actions are repeated until all the single control rods 160 to be disassembled and assembled on the control rod assembly 170 are replaced or assembled.

[0068] After the current rod position is disassembled and assembled, if there are still other rods to be disassembled and assembled, the control rod assembly 170 is lifted using hoisting equipment and rotated around the vertical axis by a preset angle so that the next rod to be disassembled and assembled is aligned with the disassembly and assembly hole 121a. It is then lowered and inserted again, and the clamping, synchronous screwing, translation, stopping, and releasing operations are repeated until all rods to be disassembled and assembled are replaced or assembled. The hoisting and repositioning device's own rotation mechanism simplifies the underwater structure and reduces the risk of failure. Precise replacement is achieved through rod-by-rod processing, adapting to assemblies with different numbers of rods, such as 24, 16, and 12.

[0069] In this embodiment, during installation, the control unit 150 monitors the actual tightening torque in real time during the tightening process. When the actual tightening torque reaches the preset installation torque value, the control unit 130 stops tightening and maintains the current torque, while simultaneously recording the actual output torque data and the corresponding rod position number. During disassembly, the control unit 150 monitors the actual tightening torque in real time during the tightening process. When the actual tightening torque experiences an abnormal surge, the control unit 150 immediately stops the clamping tightening mechanism 130 and the lifting drive mechanism 140 and issues an alarm signal.

[0070] According to the control rod automatic installation and disassembly device 101 provided in this embodiment, the working principle of the control rod automatic installation and disassembly device 101 includes: The device is fixed to a storage rack or workstation support. The control rod assembly 170 is hoisted into position, and the 24 individual control rods 160 pass through the corresponding guide holes 121 on the perforated housing 120, aligning the rod to be disassembled with the disassembly / removal position hole 121a equipped with the clamping and tightening mechanism 130. The clamping mechanism 131 clamps the rod radially, and the pressure sensor 152 confirms that the clamping force is sufficient. The tightening mechanism 132 drives the rod to rotate around its own axis, while the lifting drive mechanism 140 drives the perforated housing 120 and all its mechanisms to move synchronously along the axial direction. The control unit 150 ensures that the speed ratio of the translation speed to the tightening speed is strictly matched with the thread lead, ensuring that the thread naturally screws in or out along the helical trajectory. After tightening to the correct position, the rotation stops and the torque data is recorded. The clamping mechanism 131 is then released, completing the disassembly / removal of a single rod. All rods to be disassembled / removed can be processed sequentially by hoisting and repositioning.

[0071] The control rod single-rod automatic installation and removal device 101 provided in this embodiment has at least the following advantages: For the common operational scenario where only 1-2 out of 24 control rods are severely worn, this device uses hoisting and repositioning to align the target rods sequentially with the disassembly / removal hole 121a, allowing for precise replacement of each rod individually and avoiding the scrapping of the entire unit. Combined with automated cutting and welding tools, it can remotely complete the replacement of damaged individual rods in the high-irradiation underwater environment of the spent fuel pool, reducing personnel radiation risks and significantly lowering nuclear power plant operating costs.

[0072] The servo motor closed-loop drive replaces manual torque wrench operation, eliminating inherent tool errors and individual differences in the operator's force application angle and speed. The torque sensor 151 detects in real time, and the control unit 150 adjusts in a closed loop. During installation, the torque stops and maintains pressure when it reaches the preset value. The output torque data is digitally stored and bound to the lever position number, achieving precise and controllable tightening torque and traceable quality.

[0073] The control unit 150 ensures that the turning speed and the lifting and translation speed are strictly matched with the thread lead, and the thread naturally screws in or out along its own helical trajectory without generating additional axial force or radial bending moment.

[0074] The device features a compact structure and few moving parts, with all drive components designed for radiation resistance, enabling long-term stable operation in the high-radiation underwater environment of spent fuel pools. Operators can complete the entire process of clamping, twisting, and lifting via a remote control console, eliminating the need for close-range human intervention and fundamentally removing personnel safety risks in high-radiation environments.

[0075] This device can be fixed to the upper end of the temporary storage rack 410 for control rod assemblies in the spent fuel pool to perform replacement of damaged individual rods, and it can also be fixed to the upper end of the workstation support on the production line of the fuel manufacturing plant to perform automated assembly of control rods. The same mechanical structure and control logic can be adapted to two completely different operating environments, realizing the reuse of technology at both ends of nuclear power plant operation and maintenance and nuclear fuel manufacturing. In the replacement of damaged individual rods in the spent fuel pool of a nuclear power plant, this device 101 can be used in conjunction with matching automated cutting tools and automated welding tools: after completing the remote cutting of the worn cladding section, this device 101 completes the screwing and disassembly of the damaged individual rod and the screwing and installation of the new rod, and then the automated welding tools complete the sealing welding of the cladding tube. The entire process does not require close personnel intervention, realizing the complete remote operation of replacing damaged individual rods in a high-irradiation environment.

[0076] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A single-bar automatic installation and disassembly device for a control rod, characterized in that, include: Base; A perforated plate-shaped housing is movably disposed vertically on the base. The perforated plate-shaped housing is provided with a plurality of guide holes spaced apart circumferentially. The guide holes are used to allow a single control rod to pass through and guide the single control rod when the control rod assembly is hoisted into place. Multiple sets of clamping and screwing mechanisms are respectively disposed at some of the guide holes in the multiple guide holes. The guide holes where the clamping and screwing mechanisms are disposed are disassembly and assembly holes. Each set of clamping and screwing mechanisms is used to clamp a single control rod that extends into the corresponding disassembly and assembly hole and drive the clamped single control rod to rotate around its own axis. A lifting drive mechanism is disposed between the base and the perforated outer shell, and the lifting drive mechanism is used to drive the perforated outer shell to move vertically relative to the base; The control unit is connected to the clamping and turning mechanism and the lifting drive mechanism. The control unit is used to control the lifting drive mechanism to drive the perforated shell to drive the multiple sets of clamping and turning mechanisms to synchronously translate along the axial direction of the control rod while the clamping and turning mechanism drives the control rod to rotate, based on the thread lead between the control rod and the connecting handle, so that the turning motion is synchronized with the axial translation lead.

2. The automatic installation and disassembly device for a single control rod according to claim 1, characterized in that: Of the plurality of guide holes, the remaining guide holes other than the disassembly / assembly position holes are non-disassembly / assembly position holes. The clamping and screwing mechanism is not provided at the non-disassembly / assembly position holes. The non-disassembly / assembly position holes are used for the control rods not in the disassembly / assembly position to pass through and be radially guided. The number of disassembly / assembly position holes is less than the total number of guide holes. The plurality of disassembly / assembly position holes are evenly spaced circumferentially along the central vertical axis of the perforated shell. The circumferential spacing angle between the disassembly / assembly position holes matches the circumferential symmetrical arrangement angle of the control rods on the control rod assembly. This allows the control rods located at different radii to be aligned with the disassembly / assembly position holes in sequence when the control rod assembly rotates around the central vertical axis to different angular positions.

3. The automatic installation and disassembly device for a single control rod according to claim 1, characterized in that: Each set of clamping and screwing mechanisms includes a clamping mechanism and a screwing mechanism. The clamping mechanism is used to clamp the control rod to be disassembled and assembled. The screwing mechanism includes a rotating actuator that contacts and engages with the outer circumferential surface of the control rod. The rotating actuator is used to drive the control rod to rotate around its own axis through contact transmission when the clamping mechanism clamps the control rod.

4. The automatic installation and removal device for a single control rod according to claim 3, characterized in that: The rotating actuator of the rotating mechanism is a rotating roller; the rotating mechanism also includes a rotating drive motor and a transmission assembly connected in sequence. The power output shaft of the rotating drive motor is arranged along the radial direction of the control rod. The outer circumferential surface of the rotating roller is in contact with the outer circumferential surface of the control rod. The output end of the transmission assembly is connected to the rotating roller. The transmission assembly is used to convert the rotational output of the rotating drive motor around its own axis into the rotation of the rotating roller around its own axis. The rotating roller drives the control rod to rotate around its own axis through friction.

5. The automatic installation and disassembly device for a single control rod according to claim 4, characterized in that: The rotary drive motor is a miniature radiation-resistant servo motor; the transmission component is a hypoid gear set or a bevel gear set, the driving wheel of the hypoid gear set or bevel gear set is mounted on the power output shaft of the rotary drive motor, and the driven wheel is coaxially fixed with the rotary roller and meshes with the driving wheel.

6. The automatic installation and disassembly device for a single control rod according to claim 4, characterized in that: The clamping mechanism includes at least two clamping rollers. The turning roller and the at least two clamping rollers are circumferentially distributed on the outer periphery of the control rod in the corresponding disassembly and assembly holes. When the turning roller is in contact with the control rod, it drives the control rod to rotate through friction. The at least two clamping rollers follow the rotation of the control rod to form multi-point clamping and radial guidance for the control rod together with the turning roller.

7. The automatic installation and removal device for a single control rod according to claim 6, characterized in that: The clamping mechanism further includes a clamping drive assembly, a linkage mechanism, and an upper and lower perforated plate disposed opposite to each other. The upper and lower perforated plates have through holes corresponding to the disassembly / assembly position holes. The through holes are used for a single control rod passing through the disassembly / assembly position holes. The clamping drive assembly connects the upper and lower perforated plates and is used to adjust the vertical distance between the upper and lower perforated plates. The upper and lower perforated plates are respectively connected to the at least two clamping rollers through the linkage mechanism. When the clamping drive assembly drives the adjustment of the vertical distance between the upper and lower perforated plates, the linkage mechanism drives the at least two clamping rollers to move radially to clamp or release the single control rod.

8. The automatic installation and removal device for a single control rod according to claim 7, characterized in that: The clamping drive assembly includes a clamping servo motor and a ball screw drive pair connected by a transmission. The ball screw drive pair is connected to the upper hole plate and the lower hole plate. The clamping servo motor drives at least one of the upper hole plate and the lower hole plate to move axially through the ball screw drive pair, so as to adjust the vertical distance between the upper hole plate and the lower hole plate.

9. The automatic installation and disassembly device for a single control rod according to claim 1, characterized in that: Each clamping and screwing mechanism includes a miniature direct-drive torque motor and a miniature pneumatic chuck or miniature electric chuck integrated at the end of the miniature direct-drive torque motor. The hollow shaft of the miniature direct-drive torque motor is coaxially arranged with the corresponding guide hole. The miniature direct-drive torque motor is used to directly drive the chuck to rotate to output screwing torque to the control rod. The jaws of the miniature pneumatic chuck or miniature electric chuck are used to clamp the control rod from the outer periphery of the control rod and rotate synchronously with the hollow shaft of the miniature direct-drive torque motor.

10. The automatic installation and removal device for a single control rod according to claim 9, characterized in that: Each clamping and screwing mechanism also includes an optical fiber slip ring, which is coaxially mounted at the tail of the hollow shaft of the miniature direct-drive torque motor. The optical fiber slip ring is signal-connected to the miniature pneumatic chuck or miniature electric chuck and is used to transmit the motion control signal of the miniature pneumatic chuck or miniature electric chuck in a strong radiation environment.

11. The automatic installation and removal device for a single control rod according to claim 1, characterized in that: The lifting drive mechanism includes a base servo motor and a base ball screw transmission pair mounted on the base and connected in a transmission relationship. The base ball screw transmission pair is connected to the perforated outer shell. The base servo motor drives the base ball screw transmission pair to rotate, thereby driving the perforated outer shell to move vertically as a whole.

12. The automatic installation and removal device for a single control rod according to claim 1, characterized in that: Each clamping and screwing mechanism is further equipped with a torque sensor and / or a pressure sensor: the torque sensor is integrated into the screwing power output path and is used to detect the actual screwing torque applied to the single control rod in real time; the pressure sensor is set in the clamping force transmission path and is used to detect the actual clamping force applied to the outer circumferential surface of the single control rod in real time; the control unit is connected to the torque sensor and the pressure sensor, and the control unit is used to perform closed-loop control of the clamping force according to the feedback signal of the pressure sensor, and to start the screwing action of the clamping and screwing mechanism after the clamping force reaches the set value; the control unit is also used to perform closed-loop control of the screwing torque according to the feedback signal of the torque sensor.

13. The automatic installation and disassembly device for a single control rod according to claim 12, characterized in that: During installation, when the actual turning torque detected by the torque sensor reaches the preset installation torque value, the control unit controls the clamping and turning mechanism to stop turning and maintain the current torque, while recording and storing the actual output torque data and the corresponding rod position number.

14. A method for assembling and disassembling a single control rod, implemented using the automatic assembly and disassembly device for a single control rod as described in any one of claims 1-13, characterized in that, include: The automatic installation and disassembly device for a single control rod is fixedly installed above the temporary storage rack for control rod components or above the workstation support of the fuel assembly production line. The control rod assembly is hoisted to the underside of the automatic installation and removal device for the single control rod using hoisting equipment. The single control rod is guided by the guide hole on the perforated outer shell so that the single control rod to be installed or removed is aligned with the installation or removal position hole corresponding to the clamping and screwing mechanism. Control the clamping and screwing mechanism to clamp the corresponding control bar; Simultaneously, the clamping and screwing mechanism and the lifting drive mechanism are activated: the clamping and screwing mechanism drives the clamped control rod to rotate around its own axis, and the lifting drive mechanism drives the perforated outer shell and the clamping and screwing mechanism to translate along the axis of the control rod. The control unit controls the speed ratio of the vertical translation speed to the screwing speed to match the thread lead between the control rod and the connecting handle. After the thread of the single control rod is fully screwed into or out of the connecting handle of the control rod assembly, the clamping and screwing mechanism and the lifting drive mechanism are stopped. Control the clamping and screwing mechanism to release the control rod at the corresponding position.

15. The method for disassembling and assembling a single control rod according to claim 14, characterized in that, The method for disassembling and assembling a single control rod also includes: The disassembly and assembly holes are evenly spaced circumferentially along the central vertical axis of the perforated plate-shaped outer shell. After the disassembly and assembly of a single control rod at the current position is completed, the control rod assembly is vertically lifted by a hoisting device until the lower end of the single control rod is disengaged from the guide hole. The assembly is then rotated around the central vertical axis of the perforated plate-shaped outer shell by a preset angle equal to the circumferential interval angle between the disassembly and assembly holes, so that a group of control rods to be disassembled and assembled at the next radius position are aligned with the disassembly and assembly holes. The control rod assembly is then lowered so that the control rods to be disassembled and assembled pass through the corresponding disassembly and assembly holes. The clamping, twisting, and lifting synchronous actions are repeated until all control rods to be disassembled and assembled on the control rod assembly are replaced or assembled.

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