Electric tightening wrench for nuclear power anchoring plate and torque control method

Abstract

The present application relates to the field of wrench structure, disclose a kind of electric tightening wrench for nuclear power anchoring plate, including output shaft, torque sensor, counterforce component and rotary cooperation structure, output shaft is rotated by drive source;Torque sensor is used to detect torque;Counterforce component is connected with the torque sensor, for bearing reaction force when tightening;Rotary cooperation structure is arranged between the torque sensor and the output shaft, to enable the output shaft can be rotated relative to the torque sensor, and the torque sensor remains stationary when the output shaft rotates, to measure torque in dynamic tightening process in static mode.The beneficial effects of the present application are that the actual torque value is obtained in real time in a static mode, while overcoming the low precision defect of current control mode affected by load and voltage fluctuation, improving the precision and stability of torque measurement.

Description

Technical Field

[0001] This invention relates to the field of wrench structures, and more specifically to an electric tightening wrench for nuclear power plant anchor plates and a torque control method. Background Technology

[0002] Anchor plates are critical connecting components in the structure of nuclear power reactor buildings. Their tightening operations must strictly meet high-precision torque control requirements to ensure the quality and safety of nuclear power construction. Currently, anchor plate tightening mainly relies on electric tightening wrenches. However, with the increasing demands for construction efficiency and quality traceability in nuclear power construction, there is an urgent need for intelligent tightening equipment with high-precision torque control, real-time data acquisition, and process management capabilities.

[0003] Existing electric torque wrenches mostly use current control to indirectly calibrate torque, calculating the output torque by monitoring changes in motor current. However, the current is significantly affected by factors such as load fluctuations, power supply voltage variations, and ambient temperature, resulting in low actual torque control accuracy and difficulty in meeting the process specifications of nuclear power plant anchor plates. A few solutions using dynamic torque sensors can directly measure torque, but the sensor needs to rotate with the output shaft, leading to inherent problems such as signal wire entanglement, brush wear, and susceptibility to vibration interference. Long-term operational stability is poor, and automatic data archiving and failure alarms during tightening are not possible. Therefore, how to achieve high-precision, high-stability direct torque measurement and integrate process management functions while the output shaft rotates continuously for tightening is a pressing technical problem to be solved in this field. Summary of the Invention

[0004] To address the aforementioned technical issues, the aim is to provide an electric tightening wrench and torque control method for nuclear power plant anchor plates. This method acquires the actual torque value in real time using a static approach, while overcoming the shortcomings of current control methods, which suffer from low accuracy due to load and voltage fluctuations. This improves the accuracy and stability of torque measurement.

[0005] This invention is achieved through the following technical solution:

[0006] An electric tightening wrench for nuclear power plant anchor plates includes an output shaft, a torque sensor, a reaction force member, and a rotational engagement structure. The output shaft is driven to rotate by a drive source. The torque sensor is used to detect torque. The reaction force member is connected to the torque sensor and is used to bear the reaction force during tightening. The rotational engagement structure is disposed between the torque sensor and the output shaft so that the output shaft can rotate relative to the torque sensor, and the torque sensor remains stationary when the output shaft rotates, thereby statically measuring the torque during the dynamic tightening process.

[0007] Those skilled in the art generally believe that signal transmission and power supply to rotating components are unavoidable problems in dynamic torque measurement, and existing technologies can only alleviate them through slip rings or wireless telemetry, but cannot completely eliminate them. This invention unexpectedly discovers that by fixing the torque sensor to the housing and using a structure where the output shaft passes through the sensor's interior, the problems of signal wire entanglement and brush wear can be completely eliminated at zero cost, greatly improving the long-term operational reliability of the equipment. Therefore, this invention provides an electric tightening wrench for nuclear power plant anchor plates, which sets a rotating fit structure between the output shaft and the torque sensor, and directly connects a reaction force component to the torque sensor to bear the tightening reaction force. This allows the output shaft to rotate freely relative to the torque sensor while the torque sensor remains stationary. Thus, during the dynamic tightening process of continuous output shaft rotation, the actual torque value is obtained in real time in a static manner, effectively avoiding the signal wire entanglement, brush wear, and vibration interference problems caused by the rotation of the shaft in traditional dynamic torque sensors. It also overcomes the low accuracy defects of current control methods affected by load and voltage fluctuations, improving the accuracy and stability of torque measurement, and laying a reliable structural foundation for realizing wireless closed-loop control and automatic data archiving and non-compliance alarm functions during the tightening process.

[0008] In some embodiments, the device further includes a housing. The torque sensor includes a gear portion and a snap-fit ​​portion. The gear portion has protruding teeth on its outer periphery, and the housing has a tooth groove or protruding teeth that mesh with the protruding teeth. The rotational engagement structure is a rolling bearing. The outer ring of the rolling bearing is fixedly connected to the inner side of the gear portion, and the inner ring of the rolling bearing is fixedly connected to the output shaft. This allows the torque sensor to be circumferentially fixed and remain stationary through the meshing of the protruding teeth with the housing. At the same time, the rolling bearing accurately bears the rotational motion and radial load of the output shaft. Thus, even when the output shaft rotates at high speed, the torque sensor can still obtain a stable and vibration-free static measurement reference. It also avoids the signal wire entanglement and brush wear problems caused by the dynamic sensor rotating with the shaft, improving the long-term operational reliability of torque measurement.

[0009] In some embodiments, the reaction force member is a reaction arm, which includes a connecting part and a bent arm. The connecting part engages with the locking part of the torque sensor, and the bent arm has a parallel section parallel to the output shaft and a vertical section perpendicular to the output shaft. By engaging the connecting part of the reaction arm with the locking part of the torque sensor, and forming a parallel section parallel to the output shaft and a vertical section perpendicular to the output shaft, the reaction force of the workpiece on the reaction arm during tightening is directly and losslessly transmitted to the torque sensor, and then transmitted to the housing through the sensor body. This forms a clear and concise force transmission path, improving the response speed and sensitivity of torque measurement, while avoiding measurement errors introduced by additional force transmission members, and overcoming the structural complexity and signal interference problems caused by the independent setting of the reaction arm in the prior art.

[0010] In some embodiments, the system further includes a speed reducer and a planetary carrier. The drive source is a servo motor, which is driven by the speed reducer. The output end of the speed reducer is driven by one end of the planetary carrier, and the other end of the planetary carrier is connected to one end of the output shaft. This allows the speed and torque of the servo motor to be amplified by the speed reducer and then smoothly output by the planetary carrier, achieving high torque and low speed output from the output shaft. This provides sufficient tightening torque for tightening the anchor plate and lays the transmission foundation for subsequent stepless speed regulation control based on real-time torque feedback. This effectively solves the problem that existing electric wrenches cannot meet the process requirements of nuclear power anchor plates due to insufficient torque or unstable output.

[0011] In some embodiments, a center wheel is further included. The planetary carrier includes a primary carrier and a secondary carrier, with a retaining ring between the primary carrier and the secondary carrier. One end of the center wheel is fixedly connected to the output end of the reducer, and the other end is fixedly connected to the primary carrier. The end of the secondary carrier is fixedly connected to the output shaft. A thrust bearing is provided between the primary carrier and the housing. The inner ring of the thrust bearing is connected to the primary carrier, and the outer ring of the thrust bearing is connected to the housing. The center wheel passes through the middle of the thrust bearing and does not contact the thrust bearing. By fixing one end of the center wheel to the output end of the reducer and the other end to the first-stage frame, and fixing the end of the second-stage frame to the output shaft, and by installing a thrust bearing between the first-stage frame and the housing, with the center wheel passing through the middle of the thrust bearing without contact, the power output from the reducer directly drives the first-stage frame via the center wheel. The first-stage frame drives the second-stage frame and the output shaft to rotate through the retaining ring and transmission relationship. At the same time, the thrust bearing bears the axial force and isolates the rotation of the first-stage frame from the housing, achieving high rigidity and low friction operation of the planetary transmission system, avoiding interference between the center wheel and the thrust bearing, ensuring the smooth rotation of the output shaft, and thus improving torque transmission efficiency and tightening accuracy.

[0012] In some embodiments, a copper sleeve is further included, which is rotatably fitted onto the output shaft, with the outer side of the copper sleeve fixedly connected to the inner wall of the torque sensor. This allows the output shaft to slide against the inner side of the copper sleeve during rotation, while the outer side of the copper sleeve has no relative movement to the inner wall of the sensor. This establishes a low-friction, wear-resistant intermediate medium between the output shaft and the torque sensor, avoiding frictional heat and wear caused by direct contact between the output shaft and the inner wall of the sensor. This extends the service life of both the sensor and the output shaft, while ensuring that torque measurement is not affected by friction, further improving measurement stability.

[0013] In some embodiments, the torque sensor has a built-in Bluetooth module. This Bluetooth module wirelessly transmits the real-time torque value detected by the torque sensor to a measurement and control terminal, which is then connected to the controller of the drive source via wireless communication. By integrating the Bluetooth module into the torque sensor and using it to wirelessly transmit the detected real-time torque value to the measurement and control terminal, and enabling the measurement and control terminal to connect to the drive source controller via wireless communication, the torque signal can be transmitted to the controller without passing through slip rings, brushes, or signal lines. This eliminates communication interruptions and measurement errors caused by signal line entanglement or brush wear in traditional dynamic torque sensors. Simultaneously, it achieves real-time, contactless transmission of torque data, providing a reliable data channel for closed-loop control, and greatly simplifies and enhances the reliability of wireless signal transmission when the sensor is stationary.

[0014] In some embodiments, the Bluetooth module and the torque sensor share the same housing, and the Bluetooth module is disposed inside the housing. By sharing a housing with the torque sensor and placing the Bluetooth module inside the housing, the wireless communication unit and the torque sensing element are integrated into a compact, sealed housing. This avoids the additional interfaces and sealing failure risks associated with external antennas or separate packaging, improves the anti-interference capability of wireless signal transmission and the overall protection level of the device, simplifies the assembly process, and reduces manufacturing costs. It is particularly suitable for the stringent requirements of dustproof, moisture-proof, and vibration-proof equipment in nuclear power plant construction environments.

[0015] In some embodiments, the housing includes a middle cover, an internal gear cover, and a protective cover. The middle cover is fixedly connected to the drive source and the reducer. The internal gear cover has a toothed groove that meshes with the convex tooth. The protective cover is fixedly connected to the torque sensor. By configuring the housing into three parts—a middle cover, an internal gear cover, and a protective cover—and fixing the middle cover to the drive source and the reducer, the internal gear cover having a toothed groove that meshes with the convex tooth, and the protective cover being fixedly connected to the torque sensor, each component of the housing undertakes a different functional role: the middle cover supports the transmission system, the internal gear cover provides circumferential fixation for the torque sensor, and the protective cover protects the sensor's tail and Bluetooth module. This achieves modular structure and removable maintenance. Simultaneously, the toothed groove in the internal gear cover meshes with the convex tooth to form a reliable anti-torsional fixation, preventing the sensor from loosening during long-term use and further ensuring the long-term stability of static torque measurement.

[0016] This invention also provides a torque control method based on the aforementioned anchor plate tightening device, comprising the following steps: setting a target torque value; driving the output shaft to rotate to tighten the anchor plate while keeping the torque sensor stationary; allowing the output shaft to rotate freely relative to the torque sensor through the rotational fitting structure; transmitting the tightening reaction force to the torque sensor through the reaction force component; and acquiring the actual torque value in real time during the dynamic tightening process in a static manner; the Bluetooth module wirelessly transmitting the actual torque value to a measurement and control terminal; the measurement and control terminal wirelessly controlling the rotational speed of the drive source based on the difference between the target torque value and the actual torque value, with the rotational speed of the drive source decreasing as it approaches the maximum target torque value; stopping the drive when the actual torque value reaches the target torque value; determining whether the tightening is qualified; issuing an alarm and marking unqualified products; and storing the tightening process data. This enables static torque measurement, wireless transmission, stepless speed regulation, and process management to form a closed-loop synergy at the methodological level, achieving torque control accuracy that breaks through the limits of traditional electric wrenches (reaching within ±1%). At the same time, the torque-time curve during the tightening process can be used to predict the friction coefficient of the thread pair and detect abnormal tightening states such as jamming or stripping. This provides a brand-new, traceable digital solution for quality control in nuclear power construction, overcoming the technical challenge that existing methods cannot simultaneously meet the requirements of high precision, high stability, and traceability.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0018] 1. By setting a rotational fit structure between the output shaft and the torque sensor, and directly connecting the reaction force component to the torque sensor, the output shaft can rotate freely relative to the torque sensor while the torque sensor remains stationary. This allows for real-time acquisition of the actual torque value in a static manner during the dynamic tightening process of continuous output shaft rotation. Compared with existing current control methods, this invention avoids the influence of load, voltage fluctuations, and other factors on torque accuracy, thus improving the accuracy of torque control. Compared with existing dynamic torque sensor solutions, this invention eliminates problems such as signal wire entanglement, brush wear, and vibration interference, significantly improving the long-term operational stability of the equipment.

[0019] 2. By fixing the torque sensor to the housing and having the output shaft pass through the inside of the sensor, the long-standing problem of signal transmission and rotational power supply in this field is completely solved at zero cost. Furthermore, since the sensor remains stationary, it no longer suffers from centrifugal force and rotational vibration under high-speed rotation conditions, achieving high-precision measurement consistent with static calibration at high speeds. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0021] Figure 1 This is a structural diagram of the present invention;

[0022] Figure 2 This is a partial structural diagram of the present invention;

[0023] Figure 3 This is a partial structural diagram of the present invention;

[0024] Figure 4 This is a cross-sectional view of the present invention;

[0025] Figure 5 This is a structural diagram of the torque sensor in this invention.

[0026] The attached diagram shows the markings and corresponding component names:

[0027] 1. Bracket; 2. Servo motor; 3. Reducer; 4. Housing; 5. Reaction arm; 6. Output shaft; 7. Output end; 8. Center wheel; 9. Primary frame; 10. Convex tooth; 11. Torque sensor; 12. Thrust bearing; 13. Secondary frame; 14. Rolling bearing; 15. Retaining ring; 16. Copper sleeve; 17. Gear section; 18. Snap-fit ​​section; 41. Intermediate cover; 42. Internal gear cover; 43. Protective cover. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0029] Throughout this specification, references to "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases "an embodiment," "an example," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. Moreover, those skilled in the art will understand that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0030] In the description of this invention, the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0031] The terms "first," "second," etc., used in this invention are merely for clarity of description and are not intended to limit any order or emphasize importance. Furthermore, the term "connection" as used herein, unless otherwise specified, can refer to a direct connection or an indirect connection via other components.

[0032] Example

[0033] Those skilled in the art generally believe that signal transmission and power supply to rotating components are unavoidable problems in dynamic torque measurement, and existing technologies can only alleviate them through slip rings or wireless telemetry, but cannot completely eliminate them. This invention unexpectedly discovers that by fixing the torque sensor 11 to the housing and using a structure where the output shaft 6 passes through the sensor's interior, the problems of signal wire entanglement and brush wear can be completely eliminated at zero cost, greatly improving the long-term operational reliability of the equipment. Therefore, this embodiment 1 provides an electric tightening wrench for nuclear power plant anchor plates, such as... Figures 1-5 As shown, the device includes an output shaft 6, a torque sensor 11, a reaction force member, and a rotational fitting structure. The output shaft 6 is driven to rotate by a drive source. The torque sensor 11 is used to detect torque. The reaction force member is connected to the torque sensor 11 and is used to bear the reaction force during tightening. The rotational fitting structure is disposed between the torque sensor 11 and the output shaft 6 so that the output shaft 6 can rotate relative to the torque sensor 11, and the torque sensor 11 remains stationary when the output shaft 6 rotates, thereby measuring the torque during the dynamic tightening process in a static manner.

[0034] The output shaft 6 is located at the very front (right end) of the entire device, with its end protruding beyond the torque sensor 11. It is used to install the sleeve and directly rotate to tighten the anchor plate nut. Dynamic torque is measured statically by using the known lever arm L (the distance between the vertical section of the reaction arm 5 and the axis of the output shaft 6) as the lever arm. The tightening torque T is obtained by multiplying the reaction force F borne by the reaction arm 5 by L. The torque sensor 11 obtains T by measuring the force transmitted by the reaction arm 5 or by directly measuring the torque value (e.g., using a strain gauge).

[0035] See Figure 1The electric tightening wrench also includes a bracket 1, which is fixedly connected to a servo motor 2, a reducer 3 and a housing 4, and is used to mount the entire wrench on a workbench or a robotic arm.

[0036] See Figures 1-4 The system also includes a housing. The torque sensor 11 includes a gear portion 17 and a snap-fit ​​portion 18. The gear portion 17 has protruding teeth 10 on its outer periphery, and the housing has a tooth groove or protruding teeth 10 that mesh with the protruding teeth 10. The rotational engagement structure is a rolling bearing 14. The outer ring of the rolling bearing 14 is fixedly connected to the inner side of the gear portion 17, and the inner ring of the rolling bearing 14 is fixedly connected to the output shaft 6. This allows the torque sensor 11 to be circumferentially fixed and remain stationary through the meshing of the protruding teeth 10 with the housing. At the same time, the rolling bearing 14 precisely bears the rotational motion and radial load of the output shaft 6. Thus, even when the output shaft 6 rotates at high speed, the torque sensor 11 can still obtain a stable and vibration-free static measurement reference. It also avoids the signal wire entanglement and brush wear problems caused by the dynamic sensor rotating with the shaft, improving the long-term operational reliability of torque measurement.

[0037] Specifically, an axial clearance is maintained between the rolling bearing 14 and the end of the secondary frame 13, so that the inner ring of the rolling bearing 14 does not contact the secondary frame 13 when the output shaft 6 rotates, further reducing transmission interference.

[0038] See Figures 1-4 The reaction force component is a reaction arm 5, which includes a connecting part and a bent arm. The connecting part is engaged with the snap-fit ​​part 18 of the torque sensor 11. The bent arm has a parallel section parallel to the output shaft 6 and a vertical section perpendicular to the output shaft 6. By engaging the connecting part of the reaction arm 5 with the snap-fit ​​part 18 of the torque sensor 11, and making the bent arm of the reaction arm 5 form a parallel section parallel to the output shaft 6 and a vertical section perpendicular to the output shaft 6, the reaction force of the workpiece on the reaction arm 5 during tightening is directly and losslessly transmitted to the torque sensor 11, and then transmitted to the housing through the sensor body. This forms a clear and concise force transmission path, improving the response speed and sensitivity of torque measurement, while avoiding measurement errors introduced by additional force transmission components, and overcoming the structural complexity and signal interference problems caused by the independent setting of the reaction arm 5 in the prior art.

[0039] Specifically, the end of the vertical section perpendicular to the output shaft 6 is provided with a claw or groove to abut against the fixing component (such as a steel bar or template) adjacent to the anchor plate, so as to prevent the reaction arm 5 from rotating with the output shaft 6.

[0040] See Figures 1-4The system also includes a reducer 3 and a planetary carrier. The drive source is a servo motor 2, which is connected to the reducer 3. The output end 7 of the reducer 3 is connected to one end of the planetary carrier, and the other end of the planetary carrier is connected to one end of the output shaft 6. This allows the speed and torque of the servo motor 2 to be amplified by the reducer 3 and then smoothly output by the planetary carrier, achieving high torque and low speed output from the output shaft 6. This provides sufficient tightening torque for tightening the anchor plate and lays the transmission foundation for subsequent stepless speed regulation control based on real-time torque feedback. This effectively solves the problem that existing electric wrenches cannot meet the process requirements of nuclear power anchor plates due to insufficient torque or unstable output.

[0041] See Figures 1-4 It also includes a center wheel 8. The planetary carrier includes a primary carrier 9 and a secondary carrier 13. A retaining ring 15 is provided between the primary carrier 9 and the secondary carrier 13. One end of the center wheel 8 is fixedly connected to the output end 7 of the reducer 3, and the other end is fixedly connected to the primary carrier 9. The end of the secondary carrier 13 is fixedly connected to the output shaft 6. A thrust bearing 12 is provided between the primary carrier 9 and the housing. The inner ring of the thrust bearing 12 is connected to the primary carrier 9, and the outer ring of the thrust bearing 12 is connected to the housing. The center wheel 8 passes through the middle of the thrust bearing 12 and does not contact the thrust bearing 12. By fixing one end of the center wheel 8 to the output end 7 of the reducer 3 and the other end to the first-stage frame 9, and fixing the end of the second-stage frame 13 to the output shaft 6, and by setting a thrust bearing 12 between the first-stage frame 9 and the housing, with the center wheel 8 passing through the middle of the thrust bearing 12 without contact, the power output by the reducer 3 directly drives the first-stage frame 9 via the center wheel 8. The first-stage frame 9 drives the second-stage frame 13 and the output shaft 6 to rotate through the retaining ring 15 and the transmission relationship. At the same time, the thrust bearing 12 bears the axial force and isolates the rotation of the first-stage frame 9 from the housing, thus achieving high rigidity and low friction operation of the planetary transmission system, avoiding interference between the center wheel 8 and the thrust bearing 12, ensuring the smooth rotation of the output shaft 6, thereby improving torque transmission efficiency and tightening accuracy.

[0042] Specifically, the inner ring of the thrust bearing 12 is fixed to the first stage frame 9 by a shoulder and a locking nut, and the outer ring is pressed by the housing end cover, thereby bearing the axial reaction force generated during the tightening process.

[0043] See Figures 1-4The system also includes a copper sleeve 16, which is rotatably fitted onto the output shaft 6. The outer side of the copper sleeve 16 is fixedly connected to the inner wall of the torque sensor 11. The copper sleeve 16 is made of tin bronze or aluminum bronze, and its inner diameter is coated with grease between it and the output shaft 6. Alternatively, a self-lubricating graphite copper sleeve 16 can be used. This allows the output shaft 6 to slide against the inner side of the copper sleeve 16 during rotation, while there is no relative movement between the outer side of the copper sleeve 16 and the inner wall of the sensor. This establishes a low-friction, wear-resistant intermediate medium between the output shaft 6 and the torque sensor 11, avoiding frictional heat and wear caused by direct contact between the output shaft 6 and the inner wall of the sensor. This extends the service life of both the sensor and the output shaft 6, while ensuring that torque measurement is not affected by friction, further improving measurement stability.

[0044] See Figures 1-5 The torque sensor 11 has a built-in Bluetooth module, which wirelessly transmits the real-time torque value detected by the torque sensor 11 to a measurement and control terminal. The measurement and control terminal is connected to the controller of the drive source via wireless communication. The torque sensor 11 and the Bluetooth module are powered by a built-in battery or through an external power cord (introduced from the rear of the housing). Since the sensor is stationary, there is no need to rotate the power supply device. By integrating the Bluetooth module into the torque sensor 11, the real-time torque value detected is wirelessly transmitted to the measurement and control terminal via Bluetooth, and the measurement and control terminal is connected to the controller of the drive source via wireless communication. This eliminates the need for the torque signal to be transmitted to the controller without passing through slip rings, brushes, or signal lines. This eliminates the communication interruption and measurement error caused by signal line entanglement or brush wear in traditional dynamic torque sensors 11. At the same time, it realizes real-time, contactless transmission of torque data, providing a reliable data channel for closed-loop control, and also achieves extreme simplification and high reliability of wireless signal transmission under stationary sensor conditions.

[0045] The specific wireless protocol of the controller of the wireless control drive source of the measurement and control terminal can be Wi-Fi, Bluetooth, ZigBee or a proprietary radio frequency protocol, preferably 2.4GHz wireless communication, so as to avoid mutual interference with the Bluetooth signal of the torque sensor 11.

[0046] See Figures 1-5 The Bluetooth module and the torque sensor 11 share the same housing, with the Bluetooth module located inside the housing and the torque sensor 11 located inside the internal gear cover 42. By sharing the same housing and placing the Bluetooth module inside the housing, the wireless communication unit and the torque sensing element are integrated into a compact, sealed housing. This avoids the additional interfaces and sealing failure risks associated with external antennas or separate packaging, improving the anti-interference capability of wireless signal transmission and the overall protection level of the device. It also simplifies the assembly process and reduces manufacturing costs, making it particularly suitable for the stringent requirements of dustproof, moisture-proof, and vibration-proof equipment in nuclear power plant construction environments.

[0047] See Figures 1-4 The housing 4 includes a middle cover 41, an internal gear cover 42, and a protective cover 43. The middle cover 41 is fixedly connected to the drive source and the reducer 3. The internal gear cover 42 has a toothed groove that meshes with the protruding tooth 10. The protective cover 43 is fixedly connected to the torque sensor 11. By setting the housing into three parts—the middle cover 41, the internal gear cover 42, and the protective cover 43—and fixing the middle cover 41 to the drive source and the reducer 3, the internal gear cover 42 having a toothed groove that meshes with the protruding tooth 10, and the protective cover 43 being fixedly connected to the torque sensor 11, each component of the housing undertakes a different functional role: the middle cover 41 supports the transmission system, the internal gear cover 42 achieves circumferential fixation of the torque sensor 11, and the protective cover 43 protects the sensor tail and the Bluetooth module. This achieves modular structure and detachable maintenance. At the same time, the toothed groove in the internal gear cover 42 meshes with the protruding tooth 10 to form a reliable anti-torsional fixation, preventing the sensor from loosening during long-term use and further ensuring the long-term stability of static torque measurement.

[0048] When the electric tightening wrench is used to tighten the nuclear power plant anchor plate, the servo motor 2 drives the reducer 3, which in turn drives the output shaft 6 to rotate via the planetary carrier to tighten the anchor plate nut. At the same time, the reaction arm 5 abuts against the adjacent fixing component of the anchor plate, directly transmitting the reaction force generated by tightening to the torque sensor 11. Since the torque sensor 11 is connected to the output shaft 6 through the rolling bearing 14 and its housing 4 is fixedly engaged with the housing, the sensor remains stationary, thus measuring the actual torque value in real time during the dynamic tightening process in a static manner. This torque value is wirelessly transmitted to the measurement and control terminal via the built-in Bluetooth module. The measurement and control terminal compares the real-time torque with the preset target torque and then wirelessly controls the speed of the servo motor 2. The speed decreases as it approaches the target torque until the target torque is reached, at which point the machine stops. The terminal automatically determines whether the tightening is qualified, issues an alarm and marks unqualified products, and stores the tightening process data to achieve high-precision closed-loop control and digital management of tightening.

[0049] Example 2

[0050] Embodiment 2 of the present invention provides a torque control method for an electric tightening wrench for nuclear power anchoring plates, comprising the following steps: setting a target torque value; driving the output shaft 6 to rotate to tighten the anchoring plate, while keeping the torque sensor 11 stationary, enabling the output shaft 6 to rotate freely relative to the torque sensor 11 through the rotational mating structure, and transmitting the tightening reaction force to the torque sensor 11 through the reaction force member, so as to obtain the actual torque value during the dynamic tightening process in a static manner; the Bluetooth module wirelessly transmits the actual torque value to the measurement and control terminal; the measurement and control terminal wirelessly controls the rotational speed of the drive source according to the difference between the target torque value and the actual torque value, and the closer it is to the maximum target torque, the lower the rotational speed of the drive source; when the actual torque value reaches the target torque value, the drive is stopped, and it is judged whether the tightening is qualified, an alarm is issued and a mark is made for unqualified products, and the tightening process data is stored. This enables a closed-loop collaboration of static torque measurement, wireless transmission, stepless speed regulation, and process management at the method level, achieving a breakthrough in torque control accuracy beyond the limit of traditional electric wrenches (up to within ±1%). At the same time, the torque-time curve during the tightening process can be used to predict the friction coefficient of the thread pair and detect abnormal tightening states such as jamming or slipping of the threads, providing a new and traceable digital solution for the quality control of nuclear power construction, and overcoming the technical problems that the existing methods cannot simultaneously meet high precision, high stability, and traceability.

[0051] Specifically, the measurement and control terminal compares the actual torque value with the target torque value. If the difference is within the preset tolerance range (such as ±2%), it is determined to be qualified; otherwise, it is determined to be unqualified. For unqualified products, the measurement and control terminal triggers an alarm device (such as a buzzer or a flash lamp) through a wireless command and controls a marking device (such as an inkjet printer or a marking pen) to mark the workpiece. The measurement and control terminal records the change curve of the torque value during the tightening process with respect to time or angle, and identifies whether there are abnormal states such as burrs, jamming, slipping of the threads, or poor lubrication in the thread pair by comparing with the standard curve.

[0052] The specific implementation manners described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific implementation manners of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An electric tightening wrench for nuclear power plant anchor plates, characterized in that, include: The output shaft (6) is driven to rotate by a drive source; Torque sensor (11) is used to detect torque; A reaction force member, connected to the torque sensor (11), is used to bear the reaction force during tightening; A rotating fit structure is provided between the torque sensor (11) and the output shaft (6) so that the output shaft (6) can rotate relative to the torque sensor (11), and the torque sensor (11) remains stationary when the output shaft (6) rotates, so as to measure the torque during the dynamic tightening process in a static manner.

2. The electric tightening wrench for nuclear power plant anchor plates according to claim 1, characterized in that, It also includes a housing (4), the torque sensor (11) includes a gear part (17) and a snap-fit ​​part (18), the gear part (17) has a tooth (10) on its outer periphery, and the housing (4) has a tooth groove or tooth that meshes with the tooth (10); the rotational engagement structure is a rolling bearing (14), the outer ring of the rolling bearing (14) is fixedly connected to the inner side of the gear part (17), and the inner ring of the rolling bearing (14) is fixedly connected to the output shaft (6).

3. The electric tightening wrench for nuclear power plant anchor plates according to claim 2, characterized in that, The reaction force component is a reaction arm (5), which includes a connecting part and a bent arm. The connecting part is engaged with the snap-fit ​​part (18) of the torque sensor (11). The bent arm has a parallel section parallel to the output shaft (6) and a vertical section perpendicular to the output shaft (6).

4. The electric tightening wrench for nuclear power plant anchor plates according to claim 1, characterized in that, It also includes a speed reducer (3) and a planetary carrier. The driving source is a servo motor (2). The servo motor (2) is connected to the speed reducer (3) in a transmission connection. The output end (7) of the speed reducer (3) is connected to one end of the planetary carrier in a transmission connection. The other end of the planetary carrier is connected to one end of the output shaft (6).

5. The electric tightening wrench for nuclear power plant anchor plates according to claim 4, characterized in that, It also includes a center wheel (8). The planetary carrier includes a primary carrier (9) and a secondary carrier (13). A retaining ring (15) is provided between the primary carrier (9) and the secondary carrier (13). One end of the center wheel (8) is fixedly connected to the output end (7) of the reducer (3), and the other end is fixedly connected to the primary carrier (9). The end of the secondary carrier (13) is fixedly connected to the output shaft (6). A thrust bearing (12) is provided between the primary carrier (9) and the housing (4). The inner ring of the thrust bearing (12) is connected to the primary carrier (9), and the outer ring of the thrust bearing (12) is connected to the housing (4). The center wheel (8) passes through the middle of the thrust bearing (12) and does not contact the thrust bearing (12).

6. The electric tightening wrench for nuclear power plant anchor plates according to claim 1, characterized in that, It also includes a copper sleeve (16), which is rotatably fitted on the output shaft (6), and the outer side of the copper sleeve (16) is fixedly connected to the inner wall of the torque sensor (11).

7. The electric tightening wrench for nuclear power plant anchor plates according to claim 1, characterized in that, The torque sensor (11) has a built-in Bluetooth module. The Bluetooth module is used to wirelessly transmit the real-time torque value detected by the torque sensor (11) to the measurement and control terminal. The measurement and control terminal is connected to the controller of the drive source through wireless communication.

8. The electric tightening wrench for nuclear power plant anchor plates according to claim 7, characterized in that, The Bluetooth module and the torque sensor (11) share the same housing, and the Bluetooth module is located inside the housing (4).

9. The electric tightening wrench for nuclear power plant anchor plates according to claim 2, characterized in that, The housing (4) includes an intermediate cover (41), an internal gear cover (42), and a protective cover (43). The intermediate cover (41) is fixedly connected to the drive source and the reducer (3). The internal gear cover (42) has a tooth groove that meshes with the convex tooth (10). The protective cover (43) is fixedly connected to the torque sensor (11).

10. A torque control method for an electric tightening wrench for nuclear power plant anchor plates based on any one of claims 1 to 9, characterized in that, Includes the following steps: Set the target torque value; The output shaft (6) is driven to rotate to tighten the anchor plate, while the torque sensor (11) is kept stationary. The output shaft (6) is allowed to rotate freely relative to the torque sensor (11) through the rotational fitting structure, and the tightening reaction force is transmitted to the torque sensor (11) through the reaction force member, so as to obtain the actual torque value in the dynamic tightening process in a static manner in real time. The Bluetooth module wirelessly transmits the actual torque value to the measurement and control terminal. The measurement and control terminal wirelessly controls the rotational speed of the drive source based on the difference between the target torque value and the actual torque value, and the closer it is to the maximum target torque value, the lower the rotational speed of the drive source. When the actual torque value reaches the target torque value, the drive stops, and it is determined whether the tightening is qualified. An alarm is issued and a mark is made for unqualified products, and the tightening process data is stored.

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