Remote release and gripping device for reactor internals control rod guide cylinder bolts

Abstract

This application belongs to the field of remote bolt manipulation technology and discloses a remote loosening and gripping device for control rod guide cylinder bolts in reactor internals. It includes a tool rotation positioning base, on which are mounted bolt loosening and gripping tools and an underwater vision-assisted positioning module arranged on the same circumference. The circumference diameter is the same as the distance between the control rod guide cylinder axis and the diameter of the guide cylinder bolt. This application arranges the bolt loosening and gripping tool, the underwater vision-assisted positioning module, the guide cylinder bolt, and the bolt locking cap on a circumference of the same size, with a 90° positional relationship to each other. When the underwater vision-assisted positioning module aligns with a guide cylinder bolt using underwater vision technology, it sets the current circumferential position to zero, and the bolt loosening and gripping tool completes its initial position calibration. The encoder on the tool rotation positioning base can then accurately locate the positions of all bolts.

Description

Technical Field

[0001] This application belongs to the field of bolt remote operation technology, and in particular relates to a device for remote loosening and gripping of bolts on the guide tube of control rods of reactor internal components. Background Technology

[0002] The control rod guide tube is an important component of the reactor internals, used to guide the control rod assemblies and control the reactor's power consumption and temperature. Located at the top of the internals, the control rod guide tube is installed as follows: a locating pin at the bottom of the guide tube is inserted into the upper core plate assembly for circumferential positioning. Four guide tube bolts, evenly distributed along the circumference of the guide tube flange, connect to the upper support plate assembly, completing the fixed connection of the control rod guide tube. To prevent the guide tube bolts from loosening after tightening, bolt locking caps are designed on the outside of the bolts. The locking cap flange is spot-welded to the guide tube assembly flange. Before installation, the bolt locking caps are already spot-welded to the guide tube assembly flange, forming a single unit. Under the pressure of a special tool, the bolt locking caps deform and enter the groove in the guide tube bolt head, preventing bolt rotation and achieving the anti-loosening purpose.

[0003] The control rod guide tubes were designed with replaceability in mind during construction. The first step in replacement is to loosen and retrieve the guide tube bolts, then safely bring all removed bolts back to the shore of the in-core components pool. Therefore, the steps for loosening the guide tube bolts are as follows:

[0004] S1. Visually locate the guide cylinder bolts using underwater vision technology;

[0005] S2. Loosen the guide tube bolt locking cap and apply a large torque to cause the recessed part of the bolt locking cap to undergo plastic deformation and then turn outward to separate it from the bolt.

[0006] S3. Continue to use a small torque to loosen the guide cylinder bolt. At this time, the number of turns needs to be counted during the loosening process of the guide cylinder bolt. After there is enough space between the guide cylinder bolt and the locking nut to grip the bolt, the bolt loosening gripping tool will generate the corresponding action to grip the guide cylinder bolt.

[0007] S4. Continue to loosen the guide cylinder bolts until the torque is completely released to 0, and all guide cylinder bolts are loosened.

[0008] If the guide cylinder bolts are completely loosened without being gripped, they will be in a free state and may fall to the bottom of the in-core components, forming foreign objects, which is not allowed during the maintenance of in-core components.

[0009] To reduce the number of times the device is emptied and emptied of water, thereby lowering the environmental dose and risk on site, the process requires that all four guide tube bolts be removed before the equipment and the removed bolts are hoisted together and removed from the reactor internals pool.

[0010] Therefore, loosening and gripping the bolts is one of the key steps in replacing the guide cylinder bolts or replacing the guide cylinder.

[0011] Typically, nuclear reactor control rod guide tubes consist of 61 or 69 rods. The bolt mounting surfaces are approximately 8 meters from the refueling trolley or mobile bridge, and 5-6 meters above the water surface; the space is confined, making it inaccessible to personnel. Problems to be addressed include:

[0012] 1) Align the bolt loosening tool with the hexagonal hole of the bolt;

[0013] 2) Loosen the bolt to the specified torque to deform the locking cap and separate it from the bolt;

[0014] 3) Continue loosening the bolt until it reaches the bolt gripping position;

[0015] 4) Bolt gripping;

[0016] 5) The bolts are fully unscrewed;

[0017] 6) Bolts are stored in a dedicated bolt storage rack;

[0018] 7) Continue with the next bolt until all bolts are removed. Summary of the Invention

[0019] The purpose of this application is to provide a device for remotely loosening and gripping the bolts of the control rod guide tube of a reactor internals. This device can remove all bolts of a single guide tube in one water immersion. After the bolt removal of a single guide tube is completed, the device and the bolts it carries are hoisted together and removed from the reactor internals pool.

[0020] To achieve the above objectives, this application provides the following technical solution:

[0021] In a first aspect, this application provides a device for remotely loosening and gripping the bolts of the control rod guide tube of a reactor internal component, including a tool rotation positioning seat. The tool rotation positioning seat is equipped with bolt loosening and gripping tools and an underwater vision-assisted positioning module arranged on the same circumference. The circumference radius is the same as the distance between the control rod guide tube axis and the guide tube bolt axis.

[0022] In some embodiments, the bolt loosening gripping tool, the underwater visual auxiliary positioning module, the guide tube bolt, and the bolt locking cap are all located on the same circumference, and the bolt loosening gripping tool and the underwater visual auxiliary positioning module are arranged at 90°.

[0023] In some embodiments, the number of bolt loosening gripping tools is 2, and the bolt loosening gripping tools have two mounting positions on the tool rotation positioning seat, arranged at 180°.

[0024] In some embodiments, the bolt loosening gripping tool includes a bolt loosening gripping head section, an extension section below the upper surface of the guide cylinder, a torque transmission section, an extension section, a torque application section, a digital torque wrench, a bolt gripping operation section, and a lifting section; the bolt loosening gripping head section is fixedly connected to the extension section below the upper surface of the guide cylinder, the two extension sections are connected through the torque transmission section, the digital torque wrench applies a bolt loosening torque on the torque application section, the torque application section is connected to the bolt gripping operation section, and the lifting section is connected to the bolt gripping operation section.

[0025] In some embodiments, the bolt loosening gripping head section includes a hexagonal head, elastic jaws, an outer sleeve, a middle movable sleeve, an inner force-transmitting pin, a torque-transmitting key, an outer extension section, and an inner extension section. The outer extension section transmits torque from the extension section below the upper surface of the guide cylinder to the hexagonal head through four circumferentially arranged torque-transmitting keys. The outer sleeve is mounted on the hexagonal head. The inner extension section is guided by the inner hole of the hexagonal head and is fixedly connected to the inner force-transmitting pin. The middle movable sleeve is fixedly connected to the inner force-transmitting pin and the elastic jaws, and moves axially relative to the hexagonal head.

[0026] In some embodiments, the bolt gripping operation section includes an operation section outer sleeve, a position indicator shaft, a lead screw connection section, a lifting ring mounting flange, a bearing assembly, a rotating handle, a lead screw mandrel, and a trapezoidal nut;

[0027] The operating section outer sleeve is installed on the torque-acting section, and the inner hole of the operating section outer sleeve forms a sliding pair with the lead screw connecting section; the position indicator shaft is connected to the lead screw connecting section and forms a sliding pair with the long groove on the operating section outer sleeve; the lifting ring mounting flange is connected to the operating section outer sleeve; the trapezoidal nut is fixed to the rotating handle and is installed on the operating section outer sleeve through the bearing assembly; the lead screw connecting section is connected to the lead screw spindle.

[0028] In some embodiments, the torque transmission section includes a male torque transmission section head and a female torque transmission section head that are locked by a locking screw; the male torque transmission section head has four protruding circumferential petal structures along the circumferential direction, and the female torque transmission section head has four matching circumferential petal groove structures along the circumferential direction.

[0029] In some embodiments, the tool rotation positioning seat includes a guide cylinder mounting seat, a fixed gear ring, a bearing, a circumferential rotating pinion, a circumferential rotating motor reducer, a motor sealing cover, a circumferential rotating main frame, a tool guide sleeve, a guide column, and a tool axial limiting assembly; the guide cylinder mounting seat is mounted on the control rod guide cylinder, the fixed gear ring is mounted on the guide cylinder mounting seat, and the outer and inner rings of the bearing are respectively mounted on the guide cylinder mounting seat and the circumferential rotating main frame; the circumferential rotating motor reducer and the circumferential rotating pinion are connected by a transmission, and the motor sealing cover is fitted over the circumferential rotating motor reducer; the tool guide sleeve, the guide column, and the tool axial limiting assembly are mounted on the circumferential rotating main frame.

[0030] In some embodiments, the underwater vision-assisted positioning module carries an underwater vision camera to assist the bolt loosening gripping tool in quickly locating the circumferential position of the guide cylinder bolt.

[0031] In some embodiments, a bolt storage rack is mounted on the tool rotary positioning seat.

[0032] Compared with the prior art, the remote loosening and gripping device for control rod guide tube bolts of reactor internals provided in this application has the following advantages:

[0033] This application sets the bolt loosening gripping tool, underwater vision-assisted positioning module, guide cylinder bolt, and bolt locking cap on the same circumference, and the bolt loosening gripping tool and the underwater vision-assisted positioning module are in a 90° positional relationship with each other. When the underwater vision-assisted positioning module aligns with a guide cylinder bolt through underwater vision technology, it sets the current circumferential position to zero. The bolt loosening gripping tool has completed the initial position calibration, and the encoder on the tool's rotating positioning seat can be used to find the position of all bolts.

[0034] Furthermore, in this application, the bolts removed during the intermediate process of the bolt loosening gripping tool are placed on a bolt storage rack. The bolt storage rack has three bolt positions, and its circumferential position is on the same circumference as the guide cylinder bolt. The last guide cylinder bolt to be removed is gripped by the bolt loosening gripping tool and is not placed on the bolt storage rack.

[0035] Furthermore, this application transmits torque to the inner hexagonal head via four circumferentially arranged torque keys, which then loosen the bolt. The inner rod is fixedly connected to the inner force-transmitting pin, transmitting the moving pair to the intermediate moving sleeve and the elastic gripper mounted on it. The axial movement of the elastic gripper completes the bolt gripping action.

[0036] Furthermore, the extension section designed in this application transmits a larger torque through a torque transmission section and is easy to disassemble and transport. The four protruding circumferential petal structures on the male end of the torque transmission section correspond to the petal groove structures on the female end of the torque transmission section, and have a mating relationship. The female end of the torque transmission section has a circumferential mating surface designed at the front end of the petal groove. This allows the male and female ends of the torque transmission section to first establish an axial mating relationship, then the circumferential petal structures to circumferentially mate with the petal grooves, and finally the two sections are locked together with locking bolts to form a fixed connection structure.

[0037] Furthermore, this application designs a position indicator shaft on the bolt gripping operation section, which forms a moving pair with the long groove on the outer sleeve of the operation section. This allows for a direct display of the current position of the inner extension section and the elastic gripper, facilitating bolt gripping operations.

[0038] Furthermore, this application designs the lead screw and nut assembly at the very top of the bolt loosening gripping tool to avoid the lead screw and nut assembly bearing a large axial force. The lifting ring mounting flange is installed on the outer sleeve of the operating section, and the maximum diameter of the rotating handle is smaller than that of the lifting ring in the lifting section, thus meeting the requirement that the rotating handle can rotate a full circle during lifting. Attached Figure Description

[0039] To more clearly illustrate the technical solution of this application, the accompanying drawings used in the technical description will be briefly introduced below.

[0040] Figure 1 A frontal view structural schematic diagram of the device for remote loosening and gripping of control rod guide cylinder bolts for reactor internals provided in this application;

[0041] Figure 2 A structural schematic diagram of the rear view of the remote loosening and gripping device for the control rod guide cylinder bolts of the reactor internals provided in this application;

[0042] Figure 3 A schematic diagram of the guide cylinder bolt location provided in this application;

[0043] Figure 4 This is an assembly drawing of the bolt loosening gripping tool provided in this application;

[0044] Figure 5 Assembly drawing of the tool rotary positioning seat provided in this application;

[0045] Figure 6 A cross-sectional view of the tool rotary positioning seat provided in this application;

[0046] Figure 7 An exploded view of the head of the bolt gripping and releasing tool provided in this application;

[0047] Figure 8 This is a schematic diagram of the bolt before it is gripped, as provided in this application.

[0048] Figure 9 A schematic diagram of bolt gripping provided for this application;

[0049] Figure 10 A schematic diagram illustrating the release of bolt gripping provided in this application;

[0050] Figure 11 Assembly drawing of the torque transmission section provided in this application;

[0051] Figure 12 This is the assembly drawing of the bolt gripping operation section provided in this application;

[0052] Figure 13 A flowchart of the steps for using the device provided in this application.

[0053] Explanation of reference numerals in the attached figures:

[0054] 1. Bolt loosening gripping tool; 2. Tool rotation positioning seat; 3. Bolt storage rack; 4. Underwater vision-assisted positioning module; 5. Control rod guide tube; 6. Guide tube bolt; 7. Bolt locking cap; 8. Upper support plate;

[0055] 11. Bolt loosening gripping head section; 12. Extension section below the upper surface of the guide cylinder; 13. Torque transmission section; 14. Extension section; 15. Torque application section; 16. Digital torque wrench; 17. Bolt gripping operation section; 18. Lifting section;

[0056] 21. Guide cylinder mounting base; 22. Tool rotating seat fixing gear ring; 23. Bearing; 24. Circumferential rotating pinion; 25. Circumferential rotating motor reducer; 26. Motor sealing cover; 27. Circumferential rotating main frame; 28. Tool guide sleeve; 29. ​​Guide column; 210. Tool axial limiting assembly;

[0057] 111. Hexagonal head; 112. Elastic gripper; 113. Outer sleeve; 114. Intermediate moving sleeve; 115. Inner force transmission pin; 116. Torque transmission key; 117. Outer extension section; 118. Inner extension section;

[0058] 131. Torque transmission section male connector; 132. Locking nut; 133. Torque transmission section female connector;

[0059] 171. Operating section outer sleeve; 172. Position indicator shaft; 173. Lead screw connecting section; 174. Lifting ring mounting flange; 175. Bearing assembly; 176. Rotary handle; 177. Lead screw spindle; 178. Trapezoidal nut. Detailed Implementation

[0060] The following detailed description provides further details on specific implementation methods.

[0061] To enable remote removal and retrieval of the bolts on the control rod guide tubes of the reactor internals, a new device was designed based on the structure and working environment of the control rod guide tubes. This device must be able to remove all bolts from a single guide tube in a single water immersion. After all bolt removal of a single guide tube is completed, the device and the bolts it carries will be hoisted away from the reactor internals pool. It should be noted that the control rod guide tube 5, guide tube bolts 6, bolt locking caps 7, and upper support plate 8 are components related to the control rod guide tube bolt retrieval device and are inherent parts of the nuclear reactor internals; they are shown in the diagram for ease of understanding.

[0062] like Figures 1 to 10 As shown, this application provides a remote loosening and gripping device for control rod guide cylinder bolts of reactor internal components, including a bolt loosening and gripping tool 1, a tool rotation positioning seat 2, a bolt storage rack 3, and an underwater vision-assisted positioning module 4. The tool rotation positioning seat 2 is installed on the control rod guide cylinder 5 with the bolt to be removed, and has a unique axial and circumferential position relative to the control rod guide cylinder 5. The bolt loosening and gripping tool 1, the bolt storage rack 3, and the underwater vision-assisted positioning module 4 are installed on the tool rotation positioning seat 2.

[0063] The bolt loosening gripping tool 1 has two mounting positions on the tool rotation positioning seat 2, arranged at 180°. Both sets can be used simultaneously, or one set can be used while the other is kept as a spare. The underwater vision-assisted positioning module 4 and the bolt loosening gripping tool 1 are both at 90° angles. Furthermore, the bolt loosening gripping tool 1 and the underwater vision-assisted positioning module 4 are on the same circumference, the radius of which is the same as the distance between the axis of the control rod guide cylinder 5 and the axis of the guide cylinder bolt 6. That is, after the control rod guide cylinder bolt gripping device is installed on the control rod guide cylinder 5, the bolt loosening gripping tool 1, the underwater vision-assisted positioning module 4, the guide cylinder bolt 6, and the bolt locking cap 7 are all on a circumference of the same size.

[0064] The underwater vision-assisted positioning module 4 carries an underwater vision camera, which can assist the bolt loosening gripping tool 1 in quickly locating the circumferential position of the guide cylinder bolt 6. The specific method is as follows: when it aligns with one of the guide cylinder bolts 6 through the visual image, based on the fact that the bolt loosening gripping tool 1, the underwater vision-assisted positioning module 4, the guide cylinder bolt 6, and the bolt locking cap 7 are all on the same circumference, and the bolt loosening gripping tool 1 and the underwater vision-assisted positioning module 4 are at a 90° positional relationship with each other, the axes of the two sets of bolt loosening gripping tools 1 are exactly aligned with the axis of the guide cylinder bolt 6.

[0065] The bolt loosening gripping tool 1, the underwater vision-assisted positioning module 4, the guide cylinder bolt 6, and the bolt locking cap 7 are all on the same circumference, and the bolt loosening gripping tool 1 and the underwater vision-assisted positioning module 4 are at a 90° position relative to each other. When the underwater vision-assisted positioning module 4 aligns with a certain guide cylinder bolt using underwater vision technology, it sets the current circumferential position to zero. The bolt loosening gripping tool 1 has completed the initial position calibration, and the encoder on the tool rotation positioning seat 2 can be used to find the position of all bolts.

[0066] Bolts removed during the process of bolt loosening gripping tool 1 can be placed on bolt storage rack 3. Bolt storage rack 3 is installed between two guide cylinder bolts 6 and does not affect the bolt loosening gripping tool 1 in disassembling and assembling guide cylinder bolts 6. Bolt storage rack 3 has 3 bolt positions and can hold 3 bolts. The last guide cylinder bolt 6 to be removed is gripped by bolt loosening gripping tool 1 and is not placed on bolt storage rack 3.

[0067] like Figure 1 , Figure 2 and Figure 4 As shown, the bolt loosening gripping tool 1 includes a bolt loosening gripping head section 11, an extension section 12 below the upper surface of the guide cylinder, a torque transmission section 13, an extension section 14, a torque application section 15, a digital torque wrench 16, a bolt gripping operation section 17, and a hoisting section 18.

[0068] The bolt loosening gripping head section 11 is fixedly connected to the extension section 12 below the upper surface of the guide cylinder. The two extension sections 14 are detachable and can be quickly connected via the torque transmission section 13. The torque application section 15 is fixedly connected to the bolt gripping operation section 17, which in turn is fixedly connected to the lifting section 18. A digital torque wrench 16 is mounted on the torque application section 15, and applies bolt loosening torque to the torque application section 15.

[0069] The extension section 12 below the upper surface of the guide cylinder, the torque transmission section 13, the extension section 14, the torque application section 15, and the bolt gripping operation section 17 all contain two layers of rods, namely an outer rod and an inner rod. The outer rod is used to transmit torque, and the inner rod is used for bolt gripping operation.

[0070] The bolt loosening gripping head section 11 and the extension section 12 below the upper surface of the guide cylinder are located below the upper surface of the guide cylinder, i.e., in a relatively narrow space. The outer diameter dimension is at the smallest position of the entire bolt loosening gripping tool 1.

[0071] like Figure 1 , Figure 2 , Figure 5 and Figure 6As shown, the tool rotation positioning seat 2 includes a guide cylinder mounting seat 21, a fixed gear ring 22, a bearing 23, a circumferential rotating pinion 24, a circumferential rotating motor reducer 25, a motor sealing cover 26, a circumferential rotating main frame 27, a tool guide sleeve 28, a guide column 29, and a tool axial limiting assembly 210.

[0072] The guide tube mounting base 21 is mounted on the control rod guide tube 5, the fixed gear ring 22 is mounted on the guide tube mounting base 21, and the outer ring and inner ring of the bearing 23 are respectively mounted on the guide tube mounting base 21 and the circumferential rotating main frame 27, so that the circumferential rotating main frame 27 can rotate circumferentially relative to the guide tube mounting base 21.

[0073] The circumferential rotating pinion 24, the circumferential rotating motor reducer 25, the motor sealing cover 26, the tool guide sleeve 28, the guide column 29, and the tool axial limiting assembly 210 are all mounted on the circumferential rotating main frame 27 and can rotate a full circle relative to the guide cylinder mounting seat 21 and the fixed gear ring 22. The circumferential rotating motor reducer 25 and the circumferential rotating pinion 24 are connected by a transmission, and the circumferential rotating pinion 24 meshes with the fixed gear ring 22. The motor sealing cover 26 is fitted over the circumferential rotating motor reducer 25.

[0074] The circumferential rotation drive is achieved by a circumferential rotation motor reducer 25 driving a circumferential rotation pinion 24 to rotate with a fixed gear ring 22. The motor operates in an underwater environment, and a motor sealing cover 26 is installed externally. A dynamic seal is designed at the shaft to ensure the motor's sealing performance.

[0075] like Figure 5 As shown, guide sleeves 28 are installed in the 0° and 180° directions of the circumferential rotating main frame 27. The tool guide sleeves 28 are arranged at 180°, with two locations, for guiding the bolt loosening gripping tool 1. Two sets of bolt loosening gripping tools 1 can be installed, and both sets can be used simultaneously, or one set can be kept as a spare.

[0076] The 90° and 270° directions of the circumferential rotating main frame 27 correspond to the underwater visual auxiliary positioning module 4 and the circumferential rotating motor reducer 25, respectively. Four guide cylinder bolts 6 are evenly distributed at 90° intervals on the same circumference. The center distance between the axis of the guide sleeve 28, the underwater visual auxiliary positioning module 4, and the rotation center of the circumferential rotating main frame 27 is the same as the center distance between the guide cylinder bolt 6 and the central axis of the guide cylinder. When the underwater visual auxiliary positioning module 4 aligns with one of the guide cylinder bolts through visual positioning, according to the positional relationship, the axes of the two sets of bolt release gripping tools 1 are precisely aligned with the axis of the guide cylinder bolt 6. The bolt release gripping tool 1 can be manually operated to rotate around its own axis by an angle, causing the hexagonal head 111 of the bolt release gripping head section 11 to insert into the hexagonal hole of the guide cylinder bolt 6. After a guide tube bolt 6 is removed according to the procedure, the crane lifts the bolt loosening gripping tool a certain distance via the lifting section 18. The tool axial limiting component 210 retracts, axially limiting the bolt loosening gripping tool and placing it in a suspended position at the bottom. Then, driven by the circumferential rotary motor reducer 25, it rotates a specific angle, the tool axial limiting component 210 extends, and the bolt loosening gripping tool 1 is released from its limit, allowing the bolt to be placed on the bolt storage rack 3. When it is necessary to continue rotating a certain angle to remove subsequent bolts, the bolt loosening gripping tool 1 is lifted a certain distance again, and the tool axial limiting component 210 retracts, limiting the bolt loosening gripping tool 1. In summary, the circulating tool axial limiting component 210 cylinder can limit the tool's axial direction when rotation is needed and release the axial limit of the bolt loosening gripping tool 1 when work is required.

[0077] As one feasible method, when the bolt loosening gripping tool 1 needs to rotate, the crane lifts the bolt loosening gripping tool 1 upwards a certain distance via the lifting ring. The axial limiting component 210 cylinder retracts, axially limiting the bolt loosening gripping tool 1, placing it in a suspended state at the bottom. Then, the circumferential rotary motor reducer 25 drives it to rotate a specific angle. When the bolt loosening gripping tool 1 needs to operate the bolt, the axial limiting component 210 cylinder extends, and the bolt loosening gripping tool 1 is released from the limit. It can then descend to the operating position of the guide cylinder bolt 6.

[0078] like Figure 4 , Figures 7 to 10 As shown, the bolt loosening gripping head section 11 includes a hexagonal head 111, an elastic gripper 112, an outer sleeve 113, an intermediate moving sleeve 114, an inner force transmission pin 115, a torque transmission key 116, an outer extension section 117, and an inner extension section 118.

[0079] The outer extension 117 transmits torque from the extension 12 below the upper surface of the guide cylinder to the hexagonal head 111 via four circumferentially arranged torque transmission keys 116. The outer sleeve 113 is mounted on the hexagonal head 111. The hexagonal head 111, outer sleeve 113, and torque transmission keys 116 are fixed parts, while the rest are axially movable parts. The axial movement is powered by the axial movement of the inner extension 118, used to grip the bolt. The inner extension 118 is guided by the inner hole of the hexagonal head 111 and is fixedly connected to the inner force transmission pin 115. The intermediate moving sleeve 114 is fixedly connected to the inner force transmission pin 115 and the elastic gripper 112, and can move axially relative to the hexagonal head 111.

[0080] This application transmits torque to the inner hexagonal head 111 via four circumferentially arranged torque transmission keys 116, and the torque is transmitted through the hexagonal head 111 to loosen the bolt. The inner rod is fixedly connected to the inner force transmission pin 115 to transmit the moving pair to the intermediate moving sleeve 114 and the elastic gripper 112 mounted on it. The axial movement of the elastic gripper 112 can complete the bolt gripping action.

[0081] As an implementable method, the elastic gripper 112 grips the bolt by: the inner inclined surface of the gripper is squeezed against the guide cylinder bolt, causing elastic deformation and opening outward until it passes the bolt head of the guide cylinder bolt and reaches the bolt thread section, where it elastically contracts, holds the bolt, and thus grips the bolt.

[0082] As an feasible method, the elastic gripper 112 grips the bolt as follows: when the inner inclined surface of the gripper holds the guide cylinder bolt, it is squeezed against the bolt locking cap, causing elastic deformation and opening outwards, continuing to tighten the bolt. When it is close to the bolt mounting surface and the height of the bolt locking cap exceeds the bolt height (i.e., the elastic gripper 112 cannot contact the bolt), the crane uses the lifting ring to release the bolt and lift the gripping tool 1 upwards a certain distance, thus releasing the bolt.

[0083] like Figure 1 and Figure 11 As shown, the torque transmission section 13 is used to transmit torque between rods. Its advantages are that it meets the requirements of easy disassembly, assembly, and transportation on site, while also being able to transmit a large torque. The torque transmission section 13 includes a male torque transmission section 131, a female torque transmission section 133, and a locking screw 132. The locking screw 132 locks the mating male torque transmission section 131 and female torque transmission section 133.

[0084] The male connector 131 of the torque transmission section features four protruding circumferential petal structures, while the female connector 133 of the torque transmission section features four circumferential petal groove structures. The petal structures and petal groove structures are positioned correspondingly and have a mating relationship. Simultaneously, the female connector 133 of the torque transmission section has a circumferential mating surface at the front end of the petal grooves. This allows the male connector 131 and female connector 133 to first establish an axial mating relationship, then the circumferential petal structures mate circumferentially with the petal grooves, and finally, the two sections are locked together with a locking screw 132, forming a fixed connection structure.

[0085] like Figure 1 and Figure 12 As shown, the bolt gripping operation section 17 provides axial movement drive for the inner extension section 118 of the bolt loosening gripping head section 11. This is achieved by a lead screw and nut pair. The axial position of the nut is fixed, and its circumferential rotation drives the lead screw to move axially, forming a reciprocating driving force on the inner extension section 118. This causes the elastic gripper 112 to elastically deform and grip the guide cylinder bolt. The bolt gripping operation section 17 includes an operation section outer sleeve 171, a position indicator shaft 172, a lead screw connecting section 173, a lifting ring mounting flange 174, a bearing assembly 175, a rotating handle 176, a lead screw spindle 177, and a trapezoidal nut 178.

[0086] The operating section outer sleeve 171 is mounted on the torque-acting section 15, and the inner hole of the operating section outer sleeve 171 forms a sliding pair with the lead screw connecting section 173. The position indicator shaft 172 is fixed to the lead screw connecting section 173 and forms a sliding pair with the long groove on the operating section outer sleeve 171, which can display the current position of the inner extension section 118, facilitating bolt gripping operations. The lifting ring mounting flange 174 is fixed to the operating section outer sleeve 171 and is used for lifting and bearing the load of the entire tool, avoiding load bearing on the lead screw nut pair. The trapezoidal nut 178 is fixed to the rotating handle 176 and is mounted on the operating section outer sleeve 171 through the bearing assembly 175. It can rotate relative to the operating section outer sleeve 171, but cannot move axially. The bearing assembly 175 consists of one set of thrust ball bearings and two sets of deep groove ball bearings, which can withstand large radial forces. The lead screw connecting section 173 is fixed to the lead screw spindle 177. The manual operation of the rotating handle 176 drives the trapezoidal nut 178 to rotate, which is then converted into the axial movement of the lead screw spindle 177 via the lead screw nut pair.

[0087] The inner rod is powered by a lead screw and nut assembly on the bolt gripping section 17. The rotating handle 176 is fixedly connected to the trapezoidal nut 178, with the nut's axial position fixed but its circumferential rotation relative to the outer rod. Manually operating the rotating handle 176, via the lead screw and nut assembly, converts the movement into axial motion of the lead screw spindle 177. This circumferential rotation drives the lead screw to move axially, creating a reciprocating driving force on the inner extension section 118. This causes the elastic gripper 112 to elastically deform and grip the guide cylinder bolt.

[0088] The bolt gripping operation section 17 is designed with a position indicator shaft 172, which forms a moving pair with the long groove on the outer sleeve 171 of the operation section. It can intuitively display the current position of the inner extension section 118 and the elastic gripper 112, which facilitates the bolt gripping operation.

[0089] The lead screw and nut assembly is located at the very top of the bolt loosening gripping tool 1 to avoid the lead screw and nut assembly bearing a large axial force. The lifting ring mounting flange 174 is installed on the outer sleeve 171 of the operating section, and the maximum diameter of the rotating handle 176 is smaller than that of the lifting ring of the lifting section 18, so as to meet the requirement that the rotating handle 176 can rotate a full circle during the lifting state.

[0090] Using the aforementioned remote loosening and gripping device for the reactor internals control rod guide tube bolts, loosen and grip the guide tube bolts, then safely bring all the removed bolts back to the shore of the internals pool. For example... Figure 13 As shown, the steps are as follows:

[0091] Step 1: The control rod guide cylinder bolt gripping device is installed on the guide cylinder to be inspected. Check the position status of the two sets of bolt loosening gripping tools 1. At this time, the tool axial limit component 210 cylinder is in the retracted state, which axially limits the bolt loosening gripping tool 1. Its head is a distance away from the guide cylinder bolt and is in a suspended and rotatable state.

[0092] Step 2: Visually locate the guide cylinder bolts using underwater vision technology. After positioning, set the circumferential position of the current tool rotation positioning seat 2 to zero. The bolt is loosened and the gripping tool 1 completes the initial position calibration. Subsequently, the encoder on the tool rotation positioning seat 2 is used to locate all bolt positions.

[0093] Step 3: The axial limiting component 210 cylinder extends, the bolt loosens and the gripping tool 1 releases the limit, its head is inserted into the hexagonal hole of the bolt, and a large torque is used to loosen the guide tube bolt locking cap, so that the recessed part of the bolt locking cap undergoes plastic deformation and flips outward to separate from the bolt.

[0094] Step 4: Continue to use a small torque to loosen the guide cylinder bolt. At this time, the number of turns needs to be calculated during the loosening process of the guide cylinder bolt. After there is enough space between the guide cylinder bolt and the locking nut to grip the bolt, operate the rotating handle 176 of the bolt loosening gripping tool 1. At this time, the elastic claw squeezes the bolt locking nut, causing elastic deformation and producing a corresponding action to grip the guide cylinder bolt.

[0095] Step 5: Continue loosening the guide cylinder bolts until the torque is completely released to 0;

[0096] Step 6: The crane lifts the bolt loosening gripping tool 1 upwards a certain distance using the lifting ring. The tool axial limiting component 210 is retracted by the cylinder to axially limit the bolt loosening gripping tool 1, so that it is in a suspended state at the bottom. Then, the circumferential rotary motor reducer 25 drives it to rotate at a specific angle to reach the bolt storage position.

[0097] Step 7: The elastic gripper squeezes the bolt locking cap, causing elastic deformation and opening outward to release the guide cylinder bolt. The guide cylinder bolt is stored on the bolt storage rack and separated from the bolt loosening gripping tool 1.

[0098] Step 8: Repeat step 5 until you reach the next bolt loosening position;

[0099] Step 9: Repeat steps 2 through 5 to remove all bolts. When it is necessary to store the bolts, steps 6 and 7 for bolt storage should also be repeated.

[0100] The above description is only a specific embodiment of this application, but the protection scope of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application.

Claims

1. A device for remotely releasing and gripping the bolts of the control rod guide tube of a reactor internals, characterized in that, Includes a tool rotation positioning seat (2), on which a bolt loosening gripping tool (1) and an underwater vision-assisted positioning module (4) are mounted on the same circumference. The radius of the circumference is the same as the axis of the control rod guide cylinder (5) and the axis of the guide cylinder bolt (6). The bolt loosening gripping tool (1) includes a bolt loosening gripping head section (11), an extension section (12) below the upper surface of the guide cylinder, a torque transmission section (13), an extension section (14), a torque application section (15), a digital torque wrench (16), a bolt gripping operation section (17), and a hoisting section (18). The bolt loosening gripping head section (11) is fixedly connected to the extension section (12) below the upper surface of the guide cylinder. The two extension sections (14) are connected through the torque transmission section (13). The digital torque wrench (16) applies bolt loosening torque to the torque application section (15). The torque application section (15) is connected to the bolt gripping operation section (17). The hoisting section (18) is connected to the bolt gripping operation section (17). The torque transmission section (13) includes a torque transmission section male head (131) and a torque transmission section female head (133) locked by a locking screw (132); the torque transmission section male head (131) has four protruding circumferential petal structures along the circumferential direction, and the torque transmission section female head (133) has four circumferential petal groove structures that are adapted to it along the circumferential direction; The tool rotation positioning seat (2) includes a guide cylinder mounting seat (21), a fixed gear ring (22), a bearing (23), a circumferential rotating pinion (24), a circumferential rotating motor reducer (25), a motor sealing cover (26), a circumferential rotating main frame (27), a tool guide sleeve (28), a guide column (29), and a tool axial limiting assembly (210); the guide cylinder mounting seat (21) is mounted on the control rod guide cylinder (5), and the fixed gear ring (22) is mounted on the guide cylinder mounting seat (21). On 21), the outer ring and inner ring of the bearing (23) are respectively mounted on the guide cylinder mounting base (21) and the circumferential rotating main frame (27); the circumferential rotating motor reducer (25) and the circumferential rotating pinion (24) are connected in transmission, and the motor sealing cover (26) is sleeved on the outside of the circumferential rotating motor reducer (25); the tool guide sleeve (28), the guide column (29), and the tool axial limiting assembly (210) are mounted on the circumferential rotating main frame (27).

2. The remote loosening and gripping device for the guide cylinder bolts of the reactor internals control rods according to claim 1, characterized in that, The bolt loosening gripping tool (1), the underwater visual auxiliary positioning module (4), the guide tube bolt (6), and the bolt locking cap (7) are all on the same circumference, and the bolt loosening gripping tool (1) and the underwater visual auxiliary positioning module (4) are arranged at 90°.

3. The remote loosening and gripping device for the guide cylinder bolts of reactor internals control rods according to claim 1 or 2, characterized in that, The number of bolt loosening gripping tools (1) is 2. The bolt loosening gripping tools (1) have two installation positions on the tool rotation positioning seat (2) and are arranged at 180°.

4. The remote loosening and gripping device for the guide cylinder bolts of the reactor internals control rods according to claim 1, characterized in that, The bolt loosening gripping head section (11) includes a hexagonal head (111), an elastic gripper (112), an outer sleeve (113), a middle moving sleeve (114), an inner force transmission pin (115), a torque transmission key (116), an outer extension section (117), and an inner extension section (118). The outer extension section (117) transmits torque from the extension section (12) below the upper surface of the guide cylinder to the hexagonal head (111) through four circumferentially arranged torque transmission keys (116). The outer sleeve (113) is installed on the hexagonal head (111). The inner extension section (118) is guided by the inner hole of the hexagonal head (111) and is fixedly connected to the inner force transmission pin (115). The middle moving sleeve (114) is fixedly connected to the inner force transmission pin (115) and the elastic gripper (112) and moves axially relative to the hexagonal head (111).

5. The remote loosening and gripping device for the guide cylinder bolts of reactor internals control rods according to claim 1 or 4, characterized in that, The bolt gripping operation section (17) includes an operation section outer sleeve (171), a position indicator shaft (172), a lead screw connecting section (173), a lifting ring mounting flange (174), a bearing assembly (175), a rotating handle (176), a lead screw mandrel (177), and a trapezoidal nut (178); the operation section outer sleeve (171) is mounted on the torque action section (15), and the inner hole of the operation section outer sleeve (171) forms a sliding pair with the lead screw connecting section (173); The position indicator shaft (172) is connected to the lead screw connecting section (173) and forms a sliding pair with the long groove on the operating section outer sleeve (171); the lifting ring mounting flange (174) is connected to the operating section outer sleeve (171); the trapezoidal nut (178) is fixedly connected to the rotating handle (176) and is mounted on the operating section outer sleeve (171) through the bearing assembly (175); the lead screw connecting section (173) is connected to the lead screw spindle (177).

6. The remote loosening and gripping device for the guide cylinder bolts of the reactor internals control rods according to claim 1, characterized in that, The underwater vision-assisted positioning module (4) carries an underwater vision camera to assist the bolt loosening gripping tool (1) in quickly positioning the circumferential position of the guide cylinder bolt (6).

7. The remote loosening and gripping device for the guide cylinder bolts of reactor internals control rods according to claim 1, characterized in that, A bolt storage rack (3) is installed on the tool rotation positioning seat (2).

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