Automatic cleaning device for bolt measuring hole of reactor coolant pump of nuclear power plant

Abstract

The invention belongs to the technical field of nuclear power maintenance, and particularly relates to an automatic cleaning device for a nuclear power plant reactor coolant pump bolt measuring hole. Comprising a control and driving mechanism, a stepping and guiding mechanism, a flexible shaft mechanism, an inner hole cleaning brush head mechanism and a suction power mechanism, the control and driving mechanism is connected with the flexible shaft mechanism through a transmission flexible shaft, the suction power mechanism is arranged on the flexible shaft mechanism, and the flexible shaft mechanism is connected with the stepping and guiding mechanism. The stepping and guiding mechanism is connected with the inner hole cleaning brush head mechanism. Automatic, safe, efficient and convenient online cleaning of the main bolt measuring hole and the sealing shell bolt measuring hole of the reactor coolant pump is achieved, the working intensity and the radiation dosage of personnel are reduced, the industrial safety risk and the human error risk are avoided, the influence of nuclear-grade key sensitive equipment abnormity on the nuclear safety level of a nuclear power plant is avoided, and the working efficiency is improved. And unit health factors and economic benefits are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of nuclear power plant maintenance, and particularly relates to an automatic cleaning device for bolt measurement holes of a reactor coolant pump in a nuclear power plant. Background Art

[0002] The reactor coolant pump is a core equipment of the primary loop of a nuclear power plant and is also the only high-speed rotating equipment in the reactor coolant system of the nuclear power plant. It is used to drive the high-temperature, high-pressure and radioactive coolant to cool the reactor core and transfer the heat generated in the core to the steam generator.

[0003] As the primary loop pressure boundary of the nuclear power plant (the operating pressure of the primary loop is 15.5 Mpa and the test pressure is 22.8 MPa), the main flange of the reactor coolant pump is connected to the pump casing by 24 main bolts of 4.5″×1112 mm, and the seal housing is connected to the pump cover by 16 seal housing bolts of 2″×392.4 mm. The metal graphite wound gasket between the flange and the pump casing and between the seal housing and the pump cover ensures the integrity of the primary loop pressure boundary and prevents the leakage of radioactive media. According to the operation and maintenance technical requirements, the allowable range deviation of the bolt elongation of the reactor coolant pump is 0.04 mm. If it exceeds the allowable range, the bolt needs to be re-stretched and adjusted. And only during the ten-year overhaul can the bolts be completely disassembled and cleaned and inspected. During normal operation, affected by the high-temperature environment, after continuous operation for one overhaul cycle, there will be dirt such as rust, sludge, and dust in the inner cavity of the measurement hole for bolt elongation, which affects the accuracy of on-site bolt elongation measurement. Therefore, it is necessary to effectively clean the inner cavity of the bolt measurement hole every overhaul cycle. This cleaning work directly determines the accuracy of the measurement data and the effect of the graphite gasket sealing radioactive media, and its work efficiency directly determines the radiation dose rate level of on-site workers. However, because the bolt measurement hole of the reactor coolant pump is a typical slender hole structure, and the operation space is narrow and the environmental dose rate is high, the current industry generally uses traditional manual operation methods or simple tool operations, which takes a long actual working time, resulting in delays in the overall overhaul period, an increase in the radiation dose level of personnel in contact, and the actual effect is also greatly affected by the operator and the surrounding environment, and it is impossible to ensure the stability and reliability of the overhaul quality. With the continuous increase of domestic nuclear power installed capacity and the increasingly strict and perfect national nuclear safety supervision, the operation and maintenance of core equipment such as reactor coolant pumps in nuclear power plants are becoming more standardized and large-scale. Therefore, from both the perspective of nuclear safety and nuclear power economy, it is urgent to design and develop a special cleaning device for bolt measurement holes of reactor coolant pumps in nuclear power plants. Summary of the Invention

[0004] The object of the present invention is to provide an automatic cleaning device for the bolt measurement holes of a nuclear power plant reactor coolant pump, which meets the cleaning requirements of the tensile bolt measurement holes of the primary loop reactor coolant pump in a nuclear power plant, realizes the automatic, safe, efficient and convenient online cleaning of the main bolt measurement holes and the seal shell bolt measurement holes of the reactor coolant pump, replaces the traditional inefficient manual cleaning method, reduces the labor intensity and radiation dose of personnel, avoids industrial safety risks and human error risks, avoids the impact of abnormal conditions of nuclear-grade key sensitive equipment on the nuclear safety level of the nuclear power plant, and improves the unit health factor and economic benefits.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows: An automatic cleaning device for the bolt measurement holes of a nuclear power plant reactor coolant pump, comprising a control and drive mechanism, a stepping and guiding mechanism, a flexible shaft mechanism, an inner hole cleaning brush head mechanism and a suction power mechanism. The control and drive mechanism realizes the connection and motion transmission with the inner hole cleaning brush head mechanism through the flexible shaft mechanism. The flexible shaft mechanism is sleeved in the stepping and guiding mechanism, and the suction power mechanism is quickly connected to the upper part of the flexible shaft mechanism.

[0006] The control and drive mechanism is used to drive and control the circumferential rotation and the stepping movement along the bolt hole of the transmission flexible shaft, realize the stepless speed regulation of the output of the drive motor, monitor the automatic cleaning state of the bolt hole, and realize automatic alarm or safe shutdown in case of abnormal conditions; the control and drive mechanism adopts an ABS aviation box packaging design and is equipped with box body rollers and a pull rod, including an electrical control circuit, a touch control panel and a drive motor and a flexible shaft protection interface. The electrical control circuit and the drive motor are encapsulated inside the box body, the touch control panel and the flexible shaft protection interface are arranged on the upper part of the box body. The drive motor is a rotating power device for the transmission flexible shaft, and realizes the quick connection of the transmission flexible shaft through the square flexible shaft protection interface on the upper part of the box body. The electrical control circuit controls the action of the drive motor through a PLC to realize the reciprocating movement of the inner hole cleaning brush head mechanism in the bolt measurement hole. The touch control panel is divided into status monitoring and parameter setting, realizing functions such as cleaning object selection, stepping start and stop, feed forward and backward, feed depth and speed setting, rotation start and stop, rotation speed and cleaning process parameter setting, while monitoring the operation parameters of the drive motor and the cleaning progress and displaying them in real time on the screen. Select the automatic operation mode or the manual operation mode through the touch control panel. After completing the parameter setting, enter the unmanned automatic operation mode. In case of abnormal conditions during the operation, an alarm message will be automatically sent and the alarm data will be recorded. Select different bolt specifications for cleaning holes with different apertures, corresponding to different torque information in the database.

[0007] The stepping and guiding mechanism includes a stepping mechanism for driving the feeding movement of the flexible shaft at the upper part and a guiding mechanism for the flexible shaft to enter and exit the bolt measuring hole at the lower part. A threaded sleeve is used for connecting the guiding mechanism to the bolt to be cleaned. The guiding block is inserted and sleeved on the threaded sleeve. At the end of the stepping mechanism, two worm and gear reduction motors are installed to drive the rotation of two fixed friction wheels and two moving friction wheels respectively. The position of the fixed friction wheel is fixed, and the relative position of the moving friction wheel is adjusted by a fine-tuning handwheel. A round-hole type limit switch is installed above the fixed friction wheel, which cooperates with the induction diaphragm on the surface of the flexible shaft. Through the signal transmission between the control and driving mechanism, the reciprocating movement of the flexible shaft entering and exiting the bolt measuring hole in the automatic cleaning mode is realized. The stepping mechanism and the guiding mechanism are hinged through a plug pin, and free adjustment within a 90° range can be achieved according to the on-site space structure.

[0008] The guiding block is made of nylon.

[0009] The fixed friction wheel and the moving friction wheel adopt a U-shaped rubber-coated structure.

[0010] The flexible shaft mechanism includes a transmission core shaft and a hollow sleeve with an integrated design. The transmission core shaft is located inside the hollow sleeve. The upper end is connected to the drive motor output protection interface in the control and driving mechanism through a flexible shaft square joint. The other end is connected to the inner hole cleaning brush head in a threaded form and is locked against loosening with a fastening screw. The drive motor is radially positioned through a deep groove ball bearing installed in the adapter. The hollow sleeve is located outside the transmission core shaft. The upper end is tightly fixed to the adapter by expansion joint. The lower part is flush with the transmission core shaft and is directly open to the air. The surface of the hollow sleeve is designed with an induction diaphragm, which cooperates with the limit switch on the stepping and guiding mechanism to realize the upper and lower limits and positioning display of the flexible shaft operation. A quick connector for connecting the suction power mechanism is separately set on the side of the adapter. The drive motor drives the transmission core shaft to drive the inner hole cleaning brush head to rotate in the measuring hole, brushing the side and bottom of the inner hole. Synchronously, under the work drive of the suction power mechanism, suction is carried out through the space channel between the hollow sleeve and the transmission core shaft. Through the working form of brushing and sucking at the same time, efficient cleaning of impurities or liquids in the hole is realized.

[0011] The hollow sleeve is made of a reinforced rubber flexible composite material.

[0012] The inner hole cleaning brush head mechanism selects nylon bristles arranged in a spiral pattern and oval air flow channels arranged symmetrically, and the structure form of adding bristles to the end is adopted.

[0013] The suction power mechanism selects a portable and efficient waterproof vacuum cleaner, which is reliably connected through the quick connector of the flexible shaft mechanism.

[0014] Preparations before startup: Connect the drive flexible shaft to the control and drive mechanism through the flexible shaft square joint; thread-connect the inner hole cleaning brush head mechanism to the drive mandrel and lock it with a fastening screw; connect the suction power mechanism to the flexible shaft mechanism through a quick connector; install the stepping and guiding mechanism to the bolt to be cleaned through a threaded sleeve; install the drive flexible shaft into the stepping and guiding mechanism, and adjust the dynamic friction wheel through the fine-tuning handwheel to ensure that the clamping force of the flexible shaft is appropriate; Manual cleaning mode: Turn on the power of the control and drive mechanism and the suction power mechanism. Select the working object on the touch control screen of the control and drive mechanism according to the bolt measurement hole specifications, and set the parameter information of the rotation speed and feed speed. Start the control and drive mechanism through the manual operation on the touch control screen, and start the suction power mechanism through the start-stop switch. Clean the bolt measurement hole manually in the placement area of the control and drive mechanism; Automatic cleaning mode: Turn on the power of the control and drive mechanism and the suction power mechanism. Select the working object on the touch control screen of the control and drive mechanism according to the bolt measurement hole specifications, and set the parameter information of the rotation speed, feed speed, cleaning time, and lifting times. Start the control and drive mechanism through the automatic operation on the touch control screen, and start the suction power mechanism through the start-stop switch. Realize the automatic cleaning of the bolt measurement hole in the placement area of the control and drive mechanism, and display the automatic information of the cleaning time and cleaning progress on the control screen. In case of abnormal conditions, an alarm is issued through the control and drive mechanism; The depth information of the bolt measurement hole corresponding to the working object has been input into the background database of the control and drive mechanism in advance. After selecting the working object, the corresponding flexible shaft feed limit data is automatically matched. However, the key parameter information such as the rotation speed, feed speed, cleaning time, and lifting times can be flexibly set according to the actual on-site requirements.

[0015] The beneficial effects achieved by the present invention are as follows: The automatic cleaning device for the bolt measurement hole of the reactor coolant pump in nuclear power plants of the present invention is based on the on-site environment and operation requirements, and fully considers industrial safety standards. The structure design is simple, compact, with a small volume, easy to carry, and no safety risk of rotating parts leaking outside. From the design perspective, potential hazards to personnel and equipment are completely eliminated. At the same time, the drive mechanism can achieve variable speed control according to the actual on-site work requirements, further improving work efficiency. The actuator ensures the synchronous linkage of rotational motion and vertical motion, and the cleaning component selects appropriate materials and structures to ensure thorough cleaning of the inner wall and bottom of the measurement hole, and ensure convenient disassembly and assembly, firm and reliable fastening. The working mode can be flexibly selected as manual mode or automatic mode according to actual needs. The reciprocating motion and positioning display of the drive flexible shaft are controlled by the limit sensing signal, avoiding possible damage to the upper thread of the measurement hole, and realizing fully automatic unmanned operation.

[0016] The present invention changes the traditional manual cleaning operation process of rigid rods, improves the work efficiency and maintenance quality in radioactive environment conditions, reduces the working time (the cleaning and inspection time of a single pump can be shortened from the current 2 - 3 days to within 8 hours) and dose level, reduces the influence of human factors and the requirements for personnel technical level, realizes advanced automated operation, enhances the core capacity building level of the reactor coolant pump, and improves the integrity of the primary circuit pressure boundary of the nuclear power plant. Brief Description of the Drawings

[0017] Figure 1 It is a schematic diagram of an automatic cleaning device for the bolt measurement holes of the reactor coolant pump in a nuclear power plant; Figure 2 It is a schematic diagram of the stepping and guiding mechanism; Figure 3 It is a schematic diagram of the flexible shaft mechanism; Figure 4 It is a schematic diagram of the inner hole cleaning brush head; In the figure: 1 - Control and drive mechanism; 2 - Stepping and guiding mechanism; 3 - Flexible shaft mechanism; 4 - Inner hole cleaning brush head mechanism; 5 - Suction power mechanism; 6 - Turbine and worm reduction motor; 7 - Limit switch; 8 - Fine adjustment handwheel; 9 - Fixed friction wheel; 10 - Moving friction wheel; 11 - Guide block; 12 - Threaded sleeve; 13 - Flexible shaft square joint; 14 - Deep groove ball bearing; 15 - Adapter; 16 - Quick connector; 17 - Hollow sleeve; 18 - Transmission core shaft; 19 - Fastening screw; 20 - Inner hole cleaning brush head. Detailed Embodiment

[0018] The present invention will be described in detail below with reference to the drawings and specific embodiments.

[0019] An automatic cleaning device for the bolt measurement holes of the reactor coolant pump in a nuclear power plant includes a control and drive mechanism 1, a stepping and guiding mechanism 2, a flexible shaft mechanism 3, an inner hole cleaning brush head mechanism 4 and a suction power mechanism 5. The control and drive mechanism 1 realizes the connection and action transmission with the inner hole cleaning brush head mechanism 4 through the flexible shaft mechanism 3. The flexible shaft mechanism 3 is sleeved in the stepping and guiding mechanism 2, and the suction power mechanism 5 is quickly connected to the upper part of the flexible shaft mechanism 3.

[0020] The control and drive mechanism 1 is the central brain and key heart of this set of automatic cleaning device for the bolt measurement holes of the nuclear power plant reactor coolant pump. Considering the convenience and safety of carrying and using under complex environmental conditions, its structural layout adopts an overall integrated packaging design. Through the electrical control circuit and the drive motor unit, it is used to drive and control the circumferential rotation and the stepping movement along the bolt hole of the transmission flexible shaft, and can, according to the actual on-site working requirements, realize stepless speed regulation of the motor output through the operation panel, which is more conducive to improving work efficiency. During actual on-site use, it can be placed separately in the area with a relatively low radiation dose level. After connecting the power supply wiring and the transmission flexible shaft, it monitors the automatic cleaning status of the bolt hole through the integrated control box, and realizes automatic alarm or safe shutdown in case of abnormal conditions, reducing the radiation level and labor intensity of personnel.

[0021] The control and drive mechanism 1 adopts an ABS aviation box packaging design, and is installed with box body rollers and a pull rod for easy handling and transfer. The overall functional modules include an electrical control circuit, a touch control panel, a drive motor unit and its flexible shaft protection interface. Among them, the electrical control circuit and the drive motor unit are packaged inside the box body, and the touch control panel and the flexible shaft protection interface are arranged on the upper part of the box body. The 220V drive motor assembled in the control box is the rotating power device for the transmission flexible shaft, and realizes the quick connection of the transmission flexible shaft through the square flexible shaft protection interface on the upper part of the box body. The electrical control circuit controls the action of the drive motor through the PLC, and realizes the reciprocating movement of the inner hole cleaning brush head mechanism 4 in the bolt measurement hole according to the signal of the limit switch 7. The touch control panel is divided into two parts of display content: status monitoring and parameter setting, and can realize functions such as cleaning object selection, stepping start and stop, feeding forward and backward, feeding depth and speed setting, rotation start and stop, rotation speed and cleaning process parameter setting, etc. At the same time, it can monitor the operating parameters of the drive motor and the cleaning progress, and display them in real time on the screen. Through the touch control panel, the automatic operation mode or the manual operation mode can be selected. After the parameter setting is completed in the main interface, it can enter the unmanned automatic operation mode for operation. In case of abnormal conditions during the operation process, alarm information will be automatically sent and the alarm data will be recorded. For cleaning holes with different apertures, different bolt specifications can be selected, corresponding to different torque information in the database.

[0022] The stepping and guiding mechanism 2 is installed at the upper end of the bolt to be cleaned, and is connected and fixed to the bolt to be cleaned through a thread structure that is convenient for disassembly and assembly. Through nylon guiding blocks with relatively small frictional losses, it ensures the easy and smooth entry and exit of the flexible shaft into and out of the bolt measurement hole, reduces the installation operation time and work complexity in high-radiation-dose areas, and ensures the efficient operation of the automatic cleaning mode. The friction wheel is driven to rotate by the worm and gear reduction motor 6, and the distance between the fixed friction wheel 9 and the moving friction wheel 10 is adjusted according to the specification size of the flexible shaft to ensure that the clamping force of the flexible shaft is appropriate, which can not only play a good role in driving the flexible shaft but also avoid possible damage to the flexible shaft sleeve, realizing the stepping motion function of the flexible shaft in the bolt measurement hole. By setting a limit switch 7 on the stepping and guiding mechanism 2 and performing signal feedback and motion control with the control and driving mechanism 1, the reciprocating circular motion and positioning display of the inner hole cleaning brush head 20 driven by the flexible shaft in the bolt measurement hole under the automatic cleaning mode are realized. To avoid the influence of negative factors such as limited on-site space, a hinge structure design is adopted between the upper stepping mechanism and the lower guiding mechanism, which can be flexibly adjusted within 90° according to the actual situation on-site, and the connection dimensions of the thread sleeve 12 can be flexibly processed and adjusted according to the actual situation on-site.

[0023] The stepping and guiding mechanism 2 includes a stepping mechanism for driving the feeding motion of the flexible shaft at the upper part and a guiding mechanism for the entry and exit of the flexible shaft into and out of the bolt measurement hole at the lower part. The thread sleeve 12 is a connecting component for the guiding mechanism and the bolt to be cleaned, and its thread specification size can be processed in a matching manner according to the thread specification of the bolt to be cleaned and the on-site space. The guiding block 11 is inserted and sleeved on the thread sleeve 12, which is convenient for on-site disassembly and assembly. Its material is in the form of nylon with a relatively small coefficient of friction, playing a role in guiding and protecting the entry and exit of the flexible shaft into and out of the bolt measurement hole. Two worm and gear reduction motors 6 are installed at the end of the stepping mechanism, respectively driving the rotational motions of two fixed friction wheels 9 and two moving friction wheels 10. Among them, the position of the fixed friction wheel 9 is relatively fixed and cannot be adjusted, and the relative position of the moving friction wheel 10 can be appropriately adjusted through the fine-tuning handwheel 8 to match the transmission flexible shafts of different specification sizes. To avoid possible sliding losses between the movement of the flexible shaft and the rotation of the friction wheel, the friction wheel adopts a U-shaped rubber-coated structure. To ensure the matching of the feeding motion of the flexible shaft and the depth of the bolt measurement hole under the automatic cleaning mode of the whole device, a round-hole type limit switch 7 is installed above the fixed friction wheel 9. Cooperating with the induction diaphragm on the surface of the flexible shaft, through the signal transmission with the control and driving mechanism 1, the reciprocating motion of the flexible shaft entering and exiting the bolt measurement hole under the automatic cleaning mode is realized. For the convenience of on-site installation and use, the driving mechanism and the guiding mechanism are hinged through a plug pin and can be freely adjusted within 90° according to the on-site space structure.

[0024] The flexible shaft mechanism 3 includes a transmission core shaft 18 and a hollow sleeve 17 with an integrated modular design, which serves as the motion transmission mechanism and the suction air flow channel for the automatic cleaning device of the bolt measurement hole of the reactor coolant pump. The transmission core shaft 18 is a flexible rotating component, with its two ends respectively connected to the drive motor in the control and drive mechanism 1 and the inner hole cleaning brush head. To avoid the industrial safety risks introduced by the leakage of rotating components, the transmission core shaft 18 is arranged inside the hollow sleeve 17 and is reliably connected to the drive motor through a concealed flexible shaft square joint 13. The hollow sleeve 17 is made of a reinforced rubber flexible composite material with appropriate hardness, which not only provides safety protection for the transmission core shaft 18 but also forms an inner hole suction air flow channel in cooperation with the external suction power mechanism 5, achieving efficient cleaning of impurities or liquids in the hole through the working mode of brushing and sucking simultaneously.

[0025] The flexible shaft mechanism includes a transmission core shaft 18 and a hollow sleeve 17 with an integrated modular design. The transmission core shaft 18 is located inside the hollow sleeve 17. Its upper end is connected to the output protection interface of the drive motor in the control and drive mechanism 1 through a flexible shaft square joint 13. The other end is fixedly connected to the inner hole cleaning brush head 20 in a threaded form and is locked against loosening with a fastening screw 19. During the rotation driven by the motor, radial positioning is maintained through a deep groove ball bearing 14 installed in the adapter 15. The hollow sleeve 17 is located outside the transmission core shaft 18. Its upper end is fixedly connected to the adapter 15 through expansion joint tight fit. The lower part is flush with the transmission core shaft 18 and is directly open to the air. To achieve the automatic reciprocating feeding motion of the flexible shaft in the automatic cleaning mode, an induction diaphragm is designed on the surface of the hollow sleeve 17, which cooperates with the limit switch 7 on the stepping and guiding mechanism 2 to realize the upper and lower limits and positioning display of the flexible shaft operation. A quick connector 16 for connecting the suction power mechanism 5 is separately provided on the side of the adapter 15. The motor drives the transmission core shaft 18 to drive the inner hole cleaning brush head 20 to rotate in the measurement hole, brushing the inner hole side and bottom. Synchronously, under the driving of the suction power mechanism 5, suction is carried out through the space channel between the hollow sleeve 17 and the transmission core shaft 18, achieving efficient cleaning of impurities or liquids in the hole through the working mode of brushing and sucking simultaneously.

[0026] The inner hole cleaning brush head mechanism 4 is the core execution spare part of the automatic cleaning device of the bolt measurement hole of the reactor coolant pump. By selecting nylon bristles arranged in a spiral pattern and oval groove air flow channels arranged symmetrically, and adding bristles to the end structure, the cleaning effect and suction capacity are significantly improved. To improve the connection reliability between the inner hole cleaning brush head mechanism 4 and the transmission core shaft 18, a fastening screw 19 is added on the basis of the threaded connection for anti-loosening treatment to prevent the brush head from loosening and falling off caused by the possible reverse rotation of the motor.

[0027] To prevent damage to the surface of the measurement hole during the rotary cleaning process of the inner hole cleaning brush head mechanism 4, facilitate dust lifting, and be conducive to vacuum suction, the bristles are made of non-metallic materials such as nylon. Their circumferential structure is arranged in a spiral form, and bristles are provided at the end of the core rod to facilitate cleaning the bottom of the hole and avoid damaging the measurement hole. In order to more efficiently achieve the suction effect at the bottom of the inner hole, waist-shaped grooves are symmetrically arranged on the brush head body as the suction air flow channels. The core rod shaft handle is threadedly connected to the lower part of the drive core shaft 18 by a threaded structure and is locked by a fastening screw 19. The connection structure is simple and reliable, and can effectively prevent the brush head from loosening and falling off caused by the reverse rotation of the motor.

[0028] To improve the versatility of the suction power mechanism and avoid the overall device structure design from being too complex, the suction power mechanism 5 selects a lightweight and efficient waterproof vacuum cleaner, which is reliably connected through the quick connector 16 of the flexible shaft mechanism 3. During operation, it is placed in a low-radiation dose area together with the control and drive mechanism 1. The impurities and liquids in the inner hole are sucked through the hollow sleeve 17 of the flexible shaft mechanism 3 to improve the cleaning efficiency in the working form of brushing and sucking at the same time.

[0029] Preparations before startup: Connect the drive flexible shaft to the control and drive mechanism 1 through the flexible shaft square joint 13; threadedly connect the inner hole cleaning brush head mechanism 4 to the drive core shaft 18 and lock it with the fastening screw 19; connect the suction power mechanism 5 to the flexible shaft mechanism 3 through the quick connector 16; install the stepping and guiding mechanism 2 to the bolt to be cleaned through the threaded sleeve 12; install the drive flexible shaft into the stepping and guiding mechanism 2, and adjust the moving friction wheel 10 through the fine adjustment handwheel 8 to ensure that the clamping force of the flexible shaft is appropriate.

[0030] Manual cleaning mode: Turn on the power supplies of the control and drive mechanism 1 and the suction power mechanism 5, select the working object on the touch control screen of the control and drive mechanism 1 according to the bolt measurement hole specifications, and set parameter information such as the rotation speed and feed speed. Start the control and drive mechanism 1 through the "Manual Operation" on the touch control screen, start the suction power mechanism 5 through the start-stop switch, and clean the bolt measurement hole manually in the area where the control and drive mechanism 1 is placed.

[0031] Automatic cleaning mode: Turn on the power supplies of the control and drive mechanism 1 and the suction power mechanism 5, select the working object on the touch control screen of the control and drive mechanism 1 according to the bolt measurement hole specifications, and set parameter information such as the rotation speed, feed speed, cleaning time, and lifting times. Start the control and drive mechanism 1 through the "Automatic Operation" on the touch control screen, start the suction power mechanism 5 through the start-stop switch, and clean the bolt measurement hole through full automation in the area where the control and drive mechanism 1 is placed. Display automation information such as the cleaning time and cleaning progress on the control screen, and send an alarm through the control and drive mechanism 1 in case of abnormal conditions.

[0032] Information such as the depth of the bolt measurement hole corresponding to the working object has been input into the background database of the control and drive mechanism 1 in advance. After selecting the working object, the corresponding flexible shaft feed limit data is automatically matched. However, key parameter information such as the rotation speed, feed speed, cleaning time, and lifting times can be flexibly set according to the actual on-site requirements to achieve a balance between the cleaning effect and work efficiency.

Claims

1. An automatic cleaning device for the bolt measurement holes of a reactor coolant pump in a nuclear power plant, characterized in that: It includes a control and drive mechanism, a stepping and guiding mechanism, a flexible shaft mechanism, an inner hole cleaning brush head mechanism, and a suction power mechanism. The control and drive mechanism realizes the connection and motion transmission with the inner hole cleaning brush head mechanism through the flexible shaft mechanism. The flexible shaft mechanism is sleeved in the stepping and guiding mechanism, and the suction power mechanism is quickly connected to the upper part of the flexible shaft mechanism.

2. The automatic cleaning device for the bolt measurement holes of a reactor coolant pump in a nuclear power plant according to claim 1, characterized in that: The control and drive mechanism is used to drive and control the circumferential rotation and stepping motion along the bolt hole of the transmission flexible shaft, realize stepless speed regulation of the drive motor output, monitor the automatic cleaning status of the bolt hole, and realize automatic alarm or safe shutdown in case of abnormal conditions; the control and drive mechanism adopts an ABS aviation box packaging design and is equipped with box body rollers and a pull rod, including an electrical control circuit, a touch control panel, a drive motor, and a flexible shaft protection interface. The electrical control circuit and the drive motor are encapsulated inside the box body, the touch control panel and the flexible shaft protection interface are arranged on the upper part of the box body. The drive motor is the rotation power device of the transmission flexible shaft, and realizes the quick connection of the transmission flexible shaft through the square flexible shaft protection interface on the upper part of the box body. The electrical control circuit controls the action of the drive motor through PLC to realize the reciprocating motion of the inner hole cleaning brush head mechanism in the bolt measurement hole. The touch control panel is divided into status monitoring and parameter setting, realizing functions such as cleaning object selection, stepping start and stop, feed forward and backward, feed depth and speed setting, rotation start and stop, rotation speed and cleaning process parameter setting, while monitoring the operation parameters of the drive motor and the cleaning progress, and real-time displaying on the screen. Select the automatic operation mode or manual operation mode through the touch control panel. After completing the parameter setting, enter the unmanned automatic operation mode for operation. In case of abnormal conditions during the operation, alarm information will be automatically sent and the alarm data will be recorded. Select different bolt specifications for cleaning holes with different apertures, corresponding to different torque information in the database.

3. The automatic cleaning device for the bolt measurement holes of a reactor coolant pump in a nuclear power plant according to claim 1, characterized in that: The stepping and guiding mechanism includes a stepping mechanism for driving the flexible shaft to feed in the upper part and a guiding mechanism for the flexible shaft to enter and exit the bolt measurement hole in the lower part. The threaded sleeve is used for the connection between the guiding mechanism and the bolt to be cleaned. The guiding block is inserted and sleeved on the threaded sleeve. Two worm and gear reduction motors are installed at the end of the stepping mechanism, respectively driving the rotation of two fixed friction wheels and two moving friction wheels. The position of the fixed friction wheel is fixed, and the relative position of the moving friction wheel is adjusted through a fine adjustment handwheel. A round hole-shaped limit switch is installed above the fixed friction wheel, cooperating with the induction diaphragm on the surface of the flexible shaft, and realizing the reciprocating motion of the flexible shaft entering and exiting the bolt measurement hole in the automatic cleaning mode through the signal transmission with the control and drive mechanism. The stepping mechanism and the guiding mechanism are hinged through a plug pin, and can be freely adjusted within a range of 90° according to the on-site space structure.

4. The automatic cleaning device for the bolt measurement holes of a reactor coolant pump in a nuclear power plant according to claim 3, characterized in that: The guiding block is made of nylon.

5. The automatic cleaning device for the bolt measurement holes of a reactor coolant pump in a nuclear power plant according to claim 3, characterized in that: The fixed friction wheel and the moving friction wheel adopt a U-shaped rubber-coated structure.

6. The automatic cleaning device for the bolt measurement holes of a reactor coolant pump in a nuclear power plant according to claim 3, characterized in that: The flexible shaft mechanism includes a transmission core shaft and a hollow sleeve with an integrated modular design. The transmission core shaft is located inside the hollow sleeve. The upper end is connected to the output protection interface of the drive motor in the control and drive mechanism through a flexible shaft square joint. The other end is connected to the inner hole cleaning brush head in a threaded form and is secured against loosening using fastening screws. The drive motor is radially positioned and held in place by a deep groove ball bearing installed in the adapter. The hollow sleeve is located outside the transmission core shaft. The upper end is tightly fixed to the adapter through expansion joint. The lower part is flush with the transmission core shaft and directly open to the air. The surface of the hollow sleeve is designed with induction diaphragms, which cooperate with the limit switches on the stepping and guiding mechanism to achieve upper and lower limits and positioning display of the flexible shaft operation. A quick connector for connecting the suction power mechanism is separately provided on the side of the adapter. The drive motor drives the transmission core shaft to drive the inner hole cleaning brush head to rotate inside the measurement hole, brushing the inner side and bottom of the hole. Synchronously, under the driving of the suction power mechanism, suction is carried out through the space channel between the hollow sleeve and the transmission core shaft. High-efficiency cleaning of impurities or liquids in the hole is achieved through the working mode of brushing and sucking simultaneously.

7. The automatic cleaning device for the bolt measurement holes of a reactor coolant pump in a nuclear power plant according to claim 6, characterized in that: The hollow sleeve is made of reinforced rubber flexible composite material.

8. The automatic cleaning device for the bolt measurement holes of a reactor coolant pump in a nuclear power plant according to claim 1, characterized in that: The inner hole cleaning brush head mechanism selects nylon bristles arranged in a spiral pattern and oval air flow channels arranged symmetrically, and adds a bristle structure to the end.

9. The automatic cleaning device for the bolt measurement holes of a reactor coolant pump in a nuclear power plant according to claim 1, characterized in that: The suction power mechanism selects a portable and efficient waterproof vacuum cleaner, which is reliably connected through the quick connector of the flexible shaft mechanism.

10. The automatic cleaning device for the bolt measurement holes of a reactor coolant pump in a nuclear power plant according to claim 6, characterized in that: Preparations before startup: Connect the drive flexible shaft to the control and drive mechanism through the flexible shaft square joint; connect the inner hole cleaning brush head mechanism to the transmission core shaft in a threaded form and lock it with fastening screws; connect the suction power mechanism to the flexible shaft mechanism through the quick connector; install the stepping and guiding mechanism to the bolt to be cleaned through the threaded sleeve; insert the drive flexible shaft into the stepping and guiding mechanism, and adjust the dynamic friction wheel through the fine adjustment handwheel to ensure that the clamping force of the flexible shaft is appropriate. Manual cleaning mode: Turn on the power of the control and drive mechanism and the suction power mechanism. Select the working object on the touch control screen of the control and drive mechanism according to the bolt measurement hole specifications, and set the parameter information of the rotation speed and feed speed. Start the control and drive mechanism through the manual operation on the touch control screen, start the suction power mechanism through the start-stop switch, and clean the bolt measurement hole manually in the placement area of the control and drive mechanism. Automatic cleaning mode: Turn on the power of the control and drive mechanism and the suction power mechanism. Select the working object on the touch control screen of the control and drive mechanism according to the bolt measurement hole specifications, and set the parameter information of the rotation speed, feed speed, cleaning time, and lifting times. Start the control and drive mechanism through the automatic operation on the touch control screen, start the suction power mechanism through the start-stop switch, and achieve automatic cleaning of the bolt measurement hole in the placement area of the control and drive mechanism. The cleaning time and cleaning progress automation information are displayed on the control screen. In case of abnormal conditions, an alarm is issued through the control and drive mechanism. The depth information of the bolt measurement holes corresponding to the working object has been input into the background database of the control and drive mechanism in advance. After selecting the working object, the corresponding soft shaft feed limit data will be automatically matched. However, the key parameter information such as the rotation speed, feed speed, cleaning time, and lifting times can be flexibly set according to the actual on-site requirements.

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