Reactor internal control rod guide cylinder bolt remote loosening and grabbing device

Abstract

The invention belongs to the technical field of bolt remote operation, and discloses a reactor internal control rod guide cylinder bolt remote loosening and grabbing device which comprises a tool rotating positioning seat, and a bolt loosening and grabbing tool and an underwater vision auxiliary positioning module which are arranged on the same circumference are installed on the tool rotating positioning seat. And the distance between the circumference diameter and the axis of the control rod guide cylinder is equal to the diameter of the guide cylinder bolt. A bolt loosening and grabbing tool, an underwater vision auxiliary positioning module, guide cylinder bolts and a bolt locking cap are all arranged on the circumference of the same size and form a 90-degree position relation with one another, when the underwater vision auxiliary positioning module is aligned with a certain guide cylinder bolt through the underwater vision technology, the current circumferential position is set to be zero, and the position of the guide cylinder bolt is adjusted to be zero. When the bolts are loosened, the grabbing tool completes initial position calibration, and the positions of all the bolts can be accurately found by rotating the encoder on the positioning seat through the tool.

Description

Technical Field

[0001] The present application belongs to the technical field of remote bolt operation, and in particular relates to a remote loosening and grasping device for a guide tube bolt of a reactor internal component control rod. Background Art

[0002] The control rod guide tube is an important component of the internal components of the reactor. It is used to guide the control rod assembly and control the power consumption and temperature of the reactor. The control rod guide tube is located at the upper part of the internal components of the reactor. Its installation method is as follows: the positioning pin at the bottom of the control rod guide tube is inserted into the core upper plate assembly to complete its circumferential positioning. The four guide tube bolts evenly distributed in the circumferential direction of the control rod guide tube flange are connected to the upper support plate assembly to complete the fixed connection of the control rod guide tube. In order to prevent the guide tube bolts from loosening after tightening, a bolt locking cap is designed on the outside of the bolt. The locking cap flange is spot welded to the guide tube assembly flange. Before the guide tube bolts are installed, the bolt locking cap has been spot welded to the guide tube assembly flange to form a whole. Under the extrusion of the special tool, the bolt locking cap is deformed and enters the groove of the guide tube bolt head to prevent the bolt from rotating, thereby achieving the purpose of preventing loosening.

[0003] The control rod guide tube was designed to be replaceable during construction. The first step in replacement is to loosen the guide tube bolts and grab the guide tube bolts, then safely bring all the removed bolts back to the shore of the reactor internals pool. Therefore, the steps for loosening the guide tube bolts are as follows:

[0004] S1. Visually locate the guide cylinder bolts with the help of underwater vision technology;

[0005] S2. Loosen the bolt locking cap of the guide cylinder and use a large torque to make the concave part of the bolt locking cap plastically deform and then turn outward to separate from the bolt;

[0006] S3. Continue to use a smaller 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. When there is enough space between the guide cylinder bolt and the locking cap to grab the bolt, the bolt loosening grabbing tool will generate a corresponding action to grab the guide cylinder bolt;

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

[0008] If the guide tube bolts are all loosened without being grasped, they will be in a free state and easily fall to the bottom of the pile internal components, forming foreign objects, which is not allowed during the maintenance of the pile internal components.

[0009] In order to reduce the number of times the device enters and exits the water and reduce the on-site environmental dose and risk, during the implementation process, it is required that all four guide cylinder bolts be removed, and then the equipment and the removed bolts be hoisted out of the water together and leave the reactor internals pool.

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

[0011] Usually, the number of control rod guide tubes in a nuclear reactor is 61 or 69. The bolt installation surface is about 8 meters away from the refueling trolley or mobile bridge, and 5 to 6 meters away from the water surface. The space is small and personnel cannot get close. Problems to be solved include:

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

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

[0014] 3) Continue to loosen the bolts to the bolt grabbing position;

[0015] 4) Bolt grabbing;

[0016] 5) The bolts are completely screwed out;

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

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

[0019] The purpose of the present application is to provide a device for remotely loosening and grasping bolts of a control rod guide tube of a reactor internal component, which can complete the removal of all bolts of a single guide tube by entering the water once. After the removal of the bolts of a single guide tube is completed, the device and the bolts it carries are hoisted together and leave the internal component water pool.

[0020] In order to achieve the above objectives, this application provides the following technical solutions:

[0021] In the first aspect, the present application provides a remote loosening and grasping device for the control rod guide cylinder bolts of a reactor internal component, comprising a tool rotation positioning seat, on which a bolt loosening and grasping tool and an underwater visual auxiliary positioning module arranged on the same circumference are installed, and the circumference diameter is the same as the control rod guide cylinder axis and the distance from the guide cylinder bolt axis

[0022] In some embodiments, the bolt loosening grasping tool, the underwater visual assisted positioning module, the guide tube bolt, and the bolt locking cap are all on the same size circumference and are positioned at 90° to each other.

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

[0024] In some embodiments, the bolt loosening grabbing tool includes a bolt loosening grabbing head section, an extension section below the upper surface of the guide cylinder, a torque transmission section, an extension section, a torque action section, a digital torque wrench, a bolt grabbing operation section, and a lifting section; the bolt loosening grabbing 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 action section, the torque action section is connected to the bolt grabbing operation section, and the lifting section is connected to the bolt grabbing operation section.

[0025] In some embodiments, the bolt loosening grasping head section includes a hexagonal head section, an elastic clamp, an outer sleeve, an intermediate movable sleeve, an inner force transmission pin, a torque transmission 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 section through four circumferentially arranged torque transmission keys, and the outer sleeve is installed on the hexagonal head section; the inner extension section is guided by the inner hole of the hexagonal head section and is fixedly connected to the inner force transmission pin; the intermediate movable sleeve is fixedly connected to the inner force transmission pin and the elastic clamp, and moves axially relative to the hexagonal head section.

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

[0027] The outer sleeve of the operating section is installed on the torque application section, and the inner hole of the outer sleeve of the operating section forms a moving pair with the screw connecting section; the position indicating shaft is connected to the screw connecting section, and forms a moving pair with the long groove on the outer sleeve of the operating section; the lifting ring mounting flange is connected to the outer sleeve of the operating section; the trapezoidal nut is fixedly connected to the rotating handle and is installed on the outer sleeve of the operating section through the bearing group; the screw connecting section is connected to the screw core shaft.

[0028] In some embodiments, the torque transfer section includes a torque transfer section male head and a torque transfer section female head locked by a locking screw ring; the torque transfer section male head has four protruding circular petal structures along the circumferential direction, and the torque transfer section female head has four circumferential petal groove structures adapted thereto 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 circumferentially rotating pinion, a circumferentially rotating motor reducer, a motor sealing cover, a circumferentially rotating main frame, a tool guide sleeve, a guide column, and a tool axial limit assembly; the guide cylinder mounting seat is installed on the control rod guide cylinder, the fixed gear ring is installed on the guide cylinder mounting seat, and the outer ring and inner ring of the bearing are respectively installed on the guide cylinder mounting seat and the circumferentially rotating main frame; the circumferentially rotating motor reducer and the circumferentially rotating pinion are transmission connected, and the motor sealing cover is sleeved on the outside of the circumferentially rotating motor reducer; the tool guide sleeve, the guide column, and the tool axial limit assembly are installed on the circumferentially rotating main frame.

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

[0031] In some embodiments, a bolt storage rack is installed on the tool rotation and positioning seat.

[0032] Compared with the prior art, the remote loosening and grabbing device for the guide tube bolts of the reactor internals control rod provided by the present application has the following beneficial effects:

[0033] In this application, the bolt loosening grasping tool, underwater vision-assisted positioning module, guide tube bolts, and bolt locking caps are all arranged on the same size circle and are positioned at 90° to each other. When the underwater vision-assisted positioning module is aligned with a guide tube bolt through underwater vision technology, the current circumferential position is set to zero, and the bolt loosening grasping tool completes the initial position calibration. The encoder on the tool rotation positioning seat can be used to accurately locate the positions of all bolts.

[0034] Furthermore, the present application places the bolts removed by the bolt loosening grabbing tool in the middle process on a bolt storage rack. The bolt storage rack has three bolt positions, and their circumferential positions are on the same circle as the guide tube bolts. The last guide tube bolt to be removed is grabbed by the bolt loosening grabbing tool and is not placed on the bolt storage rack.

[0035] Furthermore, the present application transmits torque to the inner hexagonal head through four circumferentially arranged torque transmission keys, and loosens the bolt through the hexagonal head. The inner rod is fixedly connected to the inner force transmission pin to transmit the moving pair to the middle moving sleeve and the elastic clamp installed thereon, and the axial movement of the elastic clamp can complete the bolt grabbing action.

[0036] Furthermore, the extension section designed in the present application transmits a large torque through the torque transmission section and is easy to disassemble and transport. The four protruding circular petal structures of the torque transmission section male head correspond to the petal groove structure positions of the torque transmission section female head, and have a matching relationship. The torque transmission section female head is designed with a circumferential matching surface at the front end of the petal groove. The torque transmission section male head and the torque transmission section female head first have an axial matching relationship, and then the circumferential petal structure matches the circumferential petal groove, and finally the two sections are locked with a locking screw ring to form a fixed connection structure.

[0037] Furthermore, the present application designs a position indicating shaft on the bolt grasping operation section, which forms a moving pair with the long groove on the outer sleeve of the operation section, and can intuitively display the current position of the inner extension section and the elastic clamping claw, facilitating the bolt grasping operation.

[0038] Furthermore, the present application designs the screw nut pair at the top of the bolt loosening gripping tool to avoid the screw nut pair from being subjected to large axial forces. The hoisting ring mounting flange is installed on the outer sleeve of the operating section, and the maximum diameter of the rotating handle is smaller than the hoisting section hoisting ring, meeting the requirement that the rotating handle can rotate a full circle in the hoisting state. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for the technical description.

[0040] Figure 1 A schematic structural diagram of a front view of a device for remotely loosening and grasping bolts of a control rod guide tube of a reactor internal component provided in the present application;

[0041] Figure 2 A schematic diagram of the structure of the remote loosening and grabbing device for the guide tube bolts of the reactor internals provided by the present application from the back side;

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

[0043] Figure 4 Assembly drawing of the bolt loosening grab tool provided for this application;

[0044] Figure 5 Assembly drawing of the tool rotation and positioning seat provided for this application;

[0045] Figure 6 A cross-sectional view of a tool rotation positioning seat provided in the present application;

[0046] Figure 7 An exploded view of the head of the bolt grab loosening tool provided for this application;

[0047] Figure 8 Schematic diagram before the bolt grab provided for this application;

[0048] Fig. 9 Schematic diagram of bolt grab provided for this application;

[0049] Fig.10 Schematic diagram of bolt grab release provided for this application;

[0050] Fig.11 The torque transfer section assembly diagram provided for this application;

[0051] Fig.12 Assembly drawing of the bolt grabbing operation section provided for this application;

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

[0053] Description of reference numerals:

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

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

[0056] 21. Guide cylinder mounting seat; 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 limit assembly;

[0057] 111, hexagonal head; 112, elastic clamping claw; 113, outer sleeve; 114, middle movable sleeve; 115, inner force transmission pin; 116, torque transmission key; 117, outer extension section; 118, inner extension section;

[0058] 131, male head of torque transmission section; 132, locking screw ring; 133, female head of torque transmission section;

[0059] 171. Outer sleeve of operating section; 172. Position indicating shaft; 173. Screw connecting section; 174. Lifting ring mounting flange; 175. Bearing assembly; 176. Rotating handle; 177. Screw core shaft; 178. Trapezoidal nut. DETAILED DESCRIPTION

[0060] The following is further explained in detail through specific implementation methods.

[0061] In order to complete the remote removal and grasping of the control rod guide tube bolts of the in-core component, a new device is designed according to the structure and working environment of the control rod guide tube. It is necessary to realize that the equipment can be put into water once to complete the removal of all the bolts of a single guide tube. After the removal of the bolts of a single guide tube is completed, the device and the bolts it carries are hoisted together and leave the in-core component pool. It should be noted that the control rod guide tube 5, the guide tube bolt 6, the bolt locking cap 7, and the upper support plate 8 are parts related to the control rod guide tube bolt grasping device, which are inherent parts of the nuclear reactor in-core components. For ease of understanding, they are shown in the figure.

[0062] like Figures 1 to 10 As shown, the present application provides a remote loosening and grabbing device for the bolts of the control rod guide cylinder of the reactor internal component, comprising a bolt loosening and grabbing tool 1, a tool rotation positioning seat 2, a bolt storage rack 3, and an underwater visual auxiliary positioning module 4. The tool rotation positioning seat 2 is installed on the control rod guide cylinder 5 of 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 grabbing tool 1, the bolt storage rack 3, and the underwater visual auxiliary positioning module 4 are installed on the tool rotation positioning seat 2.

[0063] The bolt loosening grabbing tool 1 has two installation positions on the tool rotating positioning seat 2, arranged at 180°. Two sets can be used at the same time, or one set can be used and the other set can be kept as a standby. The two positions of the underwater visual assisted positioning module 4 and the bolt loosening grabbing tool 1 are both 90°. And the bolt loosening grabbing tool 1 and the underwater visual assisted positioning module 4 are on the same circumference, and the diameter of the circumference is the same as the distance from the axis of the control rod guide cylinder 5 to the axis of the guide cylinder bolt 6. That is, after the control rod guide cylinder bolt grabbing device is installed on the control rod guide cylinder 5, the bolt loosening grabbing tool 1, the underwater visual assisted positioning module 4, the guide cylinder bolt 6, and the bolt locking cap 7 are all on the same size circumference.

[0064] The underwater visual auxiliary positioning module 4 carries an underwater visual camera, which can assist the bolt loosening grasping tool 1 to quickly locate the circumferential position of the guide cylinder bolt 6. The specific method is: when it is aligned with one of the guide cylinder bolts 6 through the visual image, the bolt loosening grasping tool 1, the underwater visual auxiliary positioning module 4, the guide cylinder bolt 6, and the bolt locking cap 7 are all on the same size circumference and are in a 90° position relationship with each other, and the axes of the two sets of bolt loosening grasping tools 1 are just aligned with the axes of the guide cylinder bolts 6.

[0065] The bolt loosening grasping 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 size circle and are positioned at 90° to each other. When the underwater vision-assisted positioning module 4 is aligned with a guide cylinder bolt through underwater vision technology, the current circumferential position is set to zero, and the bolt loosening grasping tool 1 completes the initial position calibration. The encoder on the tool rotation positioning seat 2 can be used to accurately locate the position of all bolts.

[0066] The bolts removed by the bolt loosening grabbing tool 1 during the process can be placed on the bolt storage rack 3. The bolt storage rack 3 is installed between the two guide cylinder bolts 6 and does not affect the disassembly and assembly of the guide cylinder bolts 6 by the bolt loosening grabbing tool 1. The bolt storage rack 3 has 3 bolt positions and can hold 3 bolts. The last guide cylinder bolt 6 to be removed is grabbed by the bolt loosening grabbing tool 1 without placing the bolt storage rack 3.

[0067] like Figure 1 , Figure 2 and Figure 4 As shown, the bolt loosening grabbing tool 1 includes a bolt loosening grabbing 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 action section 15, a digital torque wrench 16, a bolt grabbing operation section 17, and a lifting section 18.

[0068] The bolt loosening grabbing 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 through the torque transmission section 13. The torque application section 15 is fixedly connected to the bolt grabbing operation section 17, and the bolt grabbing operation section 17 is fixedly connected to the lifting section 18. The digital torque wrench 16 is installed on the torque application section 15, and the digital torque wrench 16 applies the bolt loosening torque on 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 action section 15, and the bolt grabbing operation section 17 all include two layers of rods, namely an outer layer rod and an inner layer rod. The outer layer rod is used to transmit torque, and the inner layer rod is used for bolt grabbing operation.

[0070] The bolt loosening grabbing 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, that is, a relatively narrow space area. The outer diameter size belongs to the minimum position of the entire bolt loosening grabbing 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 circumferentially rotating pinion 24, a circumferentially rotating motor reducer 25, a motor sealing cover 26, a circumferentially rotating main frame 27, a tool guide sleeve 28, a guide column 29, and a tool axial limit assembly 210.

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

[0073] The circumferentially rotating pinion 24, the circumferentially rotating motor reducer 25, the motor sealing cover 26, the tool guide sleeve 28, the guide column 29, and the tool axial limit assembly 210 are all mounted on the circumferentially 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 circumferentially rotating motor reducer 25 is connected to the circumferentially rotating pinion 24 in transmission, and the circumferentially rotating pinion 24 is internally meshed with the fixed gear ring 22 for transmission. The motor sealing cover 26 is sleeved on the outside of the circumferentially rotating motor reducer 25.

[0074] The circumferential rotation drive is driven by the circumferential rotation motor reducer 25 to drive the circumferential rotation pinion 24 and the fixed gear ring 22 to generate rotational motion. The motor is in an underwater environment, a motor sealing cover 26 is installed outside the motor, and a dynamic seal is designed at the rotating shaft to ensure the sealing performance of the motor.

[0075] like Figure 5 As shown, guide sleeves 28 are installed at 0° and 180° directions of the circumferentially rotating main frame 27. The tool guide sleeves 28 are arranged at 180°, and there are two of them, which are used to guide the bolt loosening grabbing tool 1. Two sets of bolt loosening grabbing tools 1 can be installed, and both sets can be used at the same time, or one set can be kept as a standby.

[0076] The 90° and 270° directions of the circumferentially rotating main frame 27 are the underwater visual assisted positioning module 4 and the circumferentially rotating motor reducer 25, respectively. The four guide cylinder bolts 6 are evenly distributed at 90° on the same circumference. The center distance between the axis of the guide sleeve 28 and the underwater visual assisted positioning module 4 and the rotation center of the circumferentially 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 assisted positioning module 4 is aligned with one of the guide cylinder bolts through visual positioning, according to the positional relationship, the axes of the two sets of bolt loosening grasping tools 1 are just aligned with the axes of the guide cylinder bolts 6, and the bolt loosening grasping tool 1 can be manually operated to rotate an angle around its own axis so that the hexagonal head 111 of the bolt loosening grasping head section 11 is inserted into the hexagonal hole of the guide cylinder bolt 6. After a guide cylinder bolt 6 is removed according to the process, the crane lifts the bolt loosening grabbing tool upward for a distance through the hoisting section 18, and the cylinder of the tool axial limit assembly 210 is recovered, and the bolt loosening grabbing tool is axially limited so that the lower part is suspended, and then the circumferential rotating motor reducer 25 drives the tool to rotate to a specific angle, and the cylinder of the tool axial limit assembly 210 extends, and the bolt loosening grabbing tool 1 is released from the limit, and the bolt can be placed on the bolt storage rack 3. When it is necessary to continue to rotate a certain angle to continue to remove subsequent bolts, the bolt loosening grabbing tool 1 is lifted upward for a distance again, and the cylinder of the tool axial limit assembly 210 is recovered, and the bolt loosening grabbing tool 1 is limited. In short, the cylinder of the circulating tool axial limit assembly 210 can limit the tool axially when rotation is required, and release the axial limit of the bolt loosening grabbing tool 1 when work is required.

[0077] As an implementable method, when the bolt loosening grabbing tool 1 needs to rotate an angle, the crane lifts the bolt loosening grabbing tool 1 upward for a distance through the lifting ring, and the cylinder of the tool axial limit assembly 210 is recovered, and the bolt loosening grabbing tool 1 is axially limited, so that the lower part is suspended, and then the circumferential rotation motor reducer 25 drives the specific angle. When the bolt loosening grabbing tool 1 needs to operate the bolt, the cylinder of the axial limit assembly 210 extends, and the bolt loosening grabbing tool 1 is released from the limit. It can reach the operating position of the guide cylinder bolt 6 downward.

[0078] like Figure 4 , Figures 7 to 10 As shown, the bolt loosening grabbing head section 11 includes a hexagonal head 111, an elastic clamping claw 112, an outer sleeve 113, an intermediate movable 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 section 117 transfers the 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, and the outer sleeve 113 is installed on the hexagonal head 111. The hexagonal head 111, the outer sleeve 113, and the torque transmission key 116 are fixed parts, and the rest are axially movable parts. The axial movement power comes from the axial movement of the inner extension section 118, which is used to grab the bolt. 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 movable sleeve 114 is fixedly connected to the inner force transmission pin 115 and the elastic clamp 112, and can move axially relative to the hexagonal head 111.

[0080] The present application transmits torque to the inner hexagonal head 111 through four circumferentially arranged torque transmission keys 116, and loosens the bolt through the hexagonal head 111. The inner rod is fixedly connected to the inner force transmission pin 115 to transmit the moving pair to the middle moving sleeve 114 and the elastic clamp 112 installed thereon, and the axial movement of the elastic clamp 112 can complete the bolt grabbing action.

[0081] As an implementable method, the elastic clamp 112 grasps the bolt in the following manner: the inner inclined surface of the clamp is squeezed with the guide tube bolt, elastically deformed, and opened outward until it passes over the bolt cap of the guide tube bolt and reaches the bolt screw section, thereby generating elastic contraction, holding the bolt, and grasping the bolt.

[0082] As an implementable method, the elastic clamp 112 grabs the bolt in the following way: when the inner inclined surface of the clamp embraces the guide tube bolt, it is squeezed with the bolt locking cap, elastically deformed, and opens outward, and the bolt is continued to be tightened. When it is close to the bolt installation surface and the height of the bolt locking cap exceeds the height of the bolt (that is, the elastic clamp 112 cannot contact the bolt), the crane uses the lifting ring to lift the bolt loosening grasping tool 1 upward for a distance, and the bolt can be loosened.

[0083] like Figure 1 and Fig.11 As shown, the torque transmission section 13 is used to transmit torque between rods. Its characteristics are that it can meet the use requirements of easy disassembly and transportation on site on the one hand, and can transmit a large torque on the other hand. The torque transmission section 13 includes a torque transmission section male head 131, a torque transmission section female head 133, and a locking screw ring 132. The locking screw ring 132 locks the butted torque transmission section male head 131 and the torque transmission section female head 133.

[0084] The torque transmission section male head 131 is designed with four protruding circumferential petal structures along the circumferential direction, and the torque transmission section female head 133 is designed with four circumferential petal groove structures along the circumferential direction. The petal structure and the petal groove structure are corresponding in position and have a matching relationship. At the same time, the torque transmission section female head 133 is designed with a circumferential matching surface at the front end of the petal groove. The torque transmission section male head 131 and the torque transmission section female head 133 are firstly in an axial matching relationship, and then the circumferential petal structure is matched with the circumferential petal groove, and finally the two sections are locked with the locking screw ring 132 to form a fixed connection structure.

[0085] like Figure 1 and Fig.12 As shown, the bolt grabbing operation section 17 is used to provide the axial movement driving operation of the inner extension section 118 in the bolt loosening grabbing head section 11, which is realized by the lead screw nut pair. The nut has a fixed axial position, and the circumferential rotation drives the lead screw to move axially, forming a reciprocating driving force of the inner extension section 118, causing the elastic clamping claw 112 to deform elastically and grab the guide cylinder bolt. The bolt grabbing operation section 17 includes an operation section outer sleeve 171, a position indicating shaft 172, a lead screw connecting section 173, a hoisting ring mounting flange 174, a bearing group 175, a rotating handle 176, a lead screw core shaft 177, and a trapezoidal nut 178.

[0086] The outer sleeve 171 of the operating section is installed on the torque action section 15, and the inner hole of the outer sleeve 171 of the operating section forms a moving pair with the screw connecting section 173. The position indicating shaft 172 is fixedly connected to the screw connecting section 173, and forms a moving pair with the long groove on the outer sleeve 171 of the operating section, which can display the current position of the inner extension section 118, and is convenient for the bolt grabbing operation. The lifting ring mounting flange 174 is fixedly connected to the outer sleeve 171 of the operating section, and is used for the lifting load of the entire tool, avoiding the load of the screw nut pair. The trapezoidal nut 178 is fixedly connected to the rotating handle 176 and is installed on the outer sleeve 171 of the operating section through the bearing group 175. It can rotate relative to the outer sleeve 171 of the operating section, but cannot move axially. The bearing group 175 consists of a group of thrust ball bearings and two groups of deep groove ball bearings, which can withstand large radial forces. The screw connecting section 173 is fixedly connected to the screw core shaft 177. The manually operated rotating handle 176 drives the trapezoidal nut 178 to rotate, which is converted into axial movement of the screw core shaft 177 through the screw nut pair.

[0087] The power of the inner rod comes from the screw nut pair on the bolt grabbing operation section 17. The rotating handle 176 is fixedly connected to the trapezoidal nut 178. The nut is fixed in the axial position and can rotate relative to the outer rod in the circumferential direction. The manual operation of the rotating handle 176 is converted into the axial movement of the screw mandrel 177 through the screw nut pair. The circumferential rotation drives the axial movement of the screw rod, forming a reciprocating driving force of the inner extension section 118, causing the elastic clamping claw 112 to deform elastically and grab the guide cylinder bolt.

[0088] A position indicating shaft 172 is designed on the bolt grabbing operation section 17, which forms a moving pair with the long groove on the outer sleeve 171 of the operation section, and can intuitively display the current position of the inner extension section 118 and the elastic clamping claw 112, which is convenient for the bolt grabbing operation.

[0089] The screw nut pair is at the top of the bolt loosening gripping tool 1 to prevent the screw nut pair from being subjected to a large axial force. The hoisting ring mounting flange 174 is mounted on the outer sleeve 171 of the operating section, and the maximum diameter of the rotating handle 176 is smaller than the hoisting ring of the hoisting section 18, meeting the requirement that the rotating handle 176 can rotate a full circle in the hoisting state.

[0090] Use the above reactor internals control rod guide tube bolt remote loosening and grabbing device to loosen the guide tube bolts and grab the guide tube bolts, and then safely bring all the removed bolts back to the shore of the reactor internals pool. Fig.13 As shown, the steps are as follows:

[0091] Step 1: The control rod guide cylinder bolt grabbing device is installed on the guide cylinder to be inspected, and the position status of the two sets of bolt loosening grabbing tools 1 is checked. At this time, the cylinder of the tool axial limit assembly 210 is in the recovery state, and the bolt loosening grabbing tool 1 is axially limited. Its head is a certain distance away from the guide cylinder bolt and is in a suspended rotatable state;

[0092] Step 2: Use underwater vision technology to visually locate the guide cylinder bolts. After completing the positioning, set the circumferential position of the current tool rotation positioning seat 2 to zero, loosen the bolts, grab the tool 1 to complete the initial position calibration, and then use the encoder on the tool rotation positioning seat 2 to find the positions of all bolts.

[0093] Step 3: The cylinder of the axial limit assembly 210 is extended, the bolt is loosened, and the gripping tool 1 is released from the limit. The head of the gripping tool 1 is inserted into the hexagonal hole of the bolt. A larger torque is used to loosen the locking cap of the bolt of the guide cylinder, so that the concave part of the locking cap of the bolt is plastically deformed and then turned outward to separate from the bolt.

[0094] Step 4: Continue to use a smaller 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 cap to grab the bolt, operate the rotating handle 176 of the bolt loosening grabbing tool 1, and the elastic clamping claw is squeezed with the bolt locking cap and elastically deformed, and a corresponding action is generated to grab the guide cylinder bolt;

[0095] Step 5: Continue to loosen the guide cylinder bolt until the torque is completely loosened to 0;

[0096] Step 6: The crane lifts the bolt loosening grabbing tool 1 upward for a distance through the lifting ring, and the cylinder of the tool axial limit assembly 210 is recovered, and the bolt loosening grabbing tool 1 is axially limited so that the lower part is in a suspended state, and then the circumferential rotating motor reducer 25 drives it to rotate a specific angle to reach the bolt storage position;

[0097] Step 7: The elastic clamping claws are squeezed with the bolt locking cap to elastically deform and open outward to release the guide cylinder bolt. The guide cylinder bolt is stored on the bolt storage rack and separated from the bolt loosening grasping tool 1.

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

[0099] Step 9: Repeat steps 2 to 5 to remove all bolts. When the bolts need to be stored, repeat steps 6 and 7 to store the bolts.

[0100] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed in the present application should be covered within the protection scope of the present application.

Claims

1. A remote loosening and grabbing device for the guide tube bolts of the control rod of a reactor internal component, characterized in that: The invention comprises a tool rotation positioning seat (2), on which a bolt loosening grasping tool (1) and an underwater visual auxiliary positioning module (4) arranged on the same circumference are installed, and the diameter of the circumference is the same as the distance between the axis of the control rod guide tube (5) and the axis of the guide tube bolt (6).

2. The device for remotely loosening and grabbing bolts of control rod guide tubes of reactor internals according to claim 1, characterized in that: The bolt loosening grasping tool (1), the underwater visual auxiliary positioning module (4), the guide tube bolt (6), and the bolt locking cap (7) are all located on the same size circumference and are positioned at 90 degrees to each other.

3. The device for remotely loosening and grabbing bolts of control rod guide tubes of reactor internals according to claim 1 or 2, characterized in that: The number of the bolt loosening grabbing tools (1) is 2, and the bolt loosening grabbing tools (1) have two installation positions on the tool rotation positioning seat (2), which are arranged at 180 degrees.

4. The device for remotely loosening and grabbing bolts of control rod guide tubes of reactor internals according to claim 1, characterized in that: The bolt loosening grasping tool (1) comprises a bolt loosening grasping 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 action section (15), a digital torque wrench (16), a bolt grasping operation section (17), and a hoisting section (18); the bolt loosening grasping 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 via the torque transmission section (13), the digital torque wrench (16) applies a bolt loosening torque to the torque action section (15), the torque action section (15) is connected to the bolt grasping operation section (17), and the hoisting section (18) is connected to the bolt grasping operation section (17).

5. The device for remotely loosening and grabbing bolts of control rod guide tubes of reactor internals according to claim 4, characterized in that: The bolt loosening grasping head section (11) comprises a hexagonal head section (111), an elastic clamping claw (112), an outer sleeve (113), an intermediate movable 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 section (111) through four circumferentially arranged torque transmission keys (116), and the outer sleeve (113) is mounted on the hexagonal head section (111); the inner extension section (118) is guided by the inner hole of the hexagonal head section (111) and is fixedly connected to the inner force transmission pin (115); the intermediate movable sleeve (114) is fixedly connected to the inner force transmission pin (115) and the elastic clamping claw (112), and moves axially relative to the hexagonal head section (111).

6. The device for remotely loosening and grabbing bolts of control rod guide tubes of reactor internals according to claim 4 or 5, characterized in that: The bolt grabbing operation section (17) comprises an operation section outer sleeve (171), a position indicating shaft (172), a lead screw connecting section (173), a lifting ring mounting flange (174), a bearing group (175), a rotating handle (176), a lead screw core shaft (177), and a trapezoidal nut (178); the operation section outer sleeve (171) is mounted on the torque application section (15), and the inner hole of the operation section outer sleeve (171) forms a moving pair with the lead screw connecting section (173); The position indicating shaft (172) is connected to the screw connecting section (173) and forms a moving pair with the long groove on the outer sleeve (171) of the operating section; the lifting ring mounting flange (174) is connected to the outer sleeve (171) of the operating section; the trapezoidal nut (178) is fixedly connected to the rotating handle (176) and is installed on the outer sleeve (171) of the operating section through the bearing group (175); the screw connecting section (173) is connected to the screw core shaft (177).

7. The device for remotely loosening and grabbing bolts of control rod guide tubes of reactor internals according to claim 4, characterized in that: The torque transmission section (13) comprises a torque transmission section male head (131) and a torque transmission section female head (133) which are locked by a locking screw ring (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 adapted thereto along the circumferential direction.

8. The device for remotely loosening and grabbing bolts of control rod guide tubes of reactor internals according to claim 1, characterized in that: The tool rotation positioning seat (2) comprises a guide cylinder mounting seat (21), a fixed gear ring (22), a bearing (23), a circumferentially rotating pinion (24), a circumferentially rotating motor reducer (25), a motor sealing cover (26), a circumferentially 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), the outer ring and the inner ring of the bearing (23) are respectively mounted on the guide cylinder mounting seat (21) and the circumferential rotating main frame (27); the circumferential rotating motor reducer (25) and the circumferential rotating pinion (24) are transmission connected, 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 limit assembly (210) are mounted on the circumferential rotating main frame (27).

9. The device for remotely loosening and grabbing bolts of control rod guide tubes of reactor internals according to claim 1, characterized in that: The underwater visual auxiliary positioning module (4) carries an underwater visual camera to assist the bolt loosening grasping tool (1) in quickly locating the circumferential position of the guide tube bolt (6).

10. The device for remotely loosening and grabbing bolts of control rod guide tubes of reactor internals 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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