Nut automatic pre-tightening device suitable for narrow space of top cover and using method thereof

Abstract

This invention provides an automatic nut pre-tightening device and its method of use suitable for confined spaces in roof covers. It includes a movable device located on the surface of the nut on the roof cover, which can move along the annular direction of the nut. The movable device contains a fastening mechanism for automatically pre-tightening the nut. Several vision cameras are located at both ends of the movable device to detect the nut's position in real time, providing visual guidance for the device's movement and positioning. This invention can adapt to the annular arc contour of the roof cover, solving the problem that traditional rigid automated equipment cannot adapt to arc-shaped working spaces. It can meet the roof cover operation needs of different specifications of hydro-generator sets. The entire pre-tightening process requires no manual intervention and can automatically complete the continuous pre-tightening of hundreds of nuts, making it easier and more efficient.

Description

Technical Field

[0001] This invention relates to the field of hydro-generator installation and maintenance technology, specifically to an automatic nut pre-tightening device suitable for the confined space of the top cover and its usage method. Background Technology

[0002] During the installation and maintenance of large rotating equipment such as hydro-generator sets, the sealing and fixing of the equipment top cover requires a large number of high-strength bolts. The pre-tightening quality of these bolts directly determines the operational safety and sealing performance of the equipment. Currently, the pre-tightening of bolts on the top cover of hydro-generator sets is mostly done manually using hydraulic torque wrenches. However, the installation area for the top cover bolts is often a narrow annular space, limiting the operating space and introducing several drawbacks to manual operation.

[0003] Firstly, manual pre-tightening is extremely labor-intensive. There can be hundreds of bolts on the top cover of a single unit. Pre-tightening a single bolt requires repeated operations, resulting in very low work efficiency and a long work cycle, which seriously affects the maintenance or installation schedule of the unit. Manual operation has poor positioning accuracy, making it difficult to achieve precise alignment between bolts and wrenches in confined spaces. It is also difficult to ensure the consistency of pre-tightening torque, which can easily lead to insufficient or excessive pre-tightening force, affecting the quality of equipment installation. In severe cases, it can cause major safety accidents such as failure of the top cover seal or bolt breakage. Furthermore, the field of vision is limited when operating manually in a confined space. Workers need to crouch in a narrow annular gap to operate, which poses a significant safety hazard and is prone to accidents such as collisions and crushing. Existing automated bolt pre-tightening equipment is mostly fixed or large gantry structure, which cannot be adapted to the narrow annular arc space of the top cover, lacks autonomous navigation and precise positioning capabilities, and makes it difficult to achieve continuous automated pre-tightening of multiple bolts; or it adopts the form of moving the edge of the bolt and nut connection surface of the top cover, which can easily affect the movement of surrounding equipment and devices, and cannot meet the needs of on-site operations. Summary of the Invention

[0004] The main objective of this invention is to provide an automatic nut pre-tightening device and its usage method suitable for narrow spaces in top covers, solving the problem that existing automatic nut pre-tightening equipment cannot adapt to the narrow annular arc space of top covers.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: An automatic nut pre-tightening device suitable for confined spaces in a top cover includes a movable device located on the surface of the top cover nut, the movable device being movable along the annular direction of the nut; a fastening mechanism is provided within the movable device for automatically pre-tightening the top cover nut; several vision cameras are provided at both ends of the movable device for real-time detection of the nut's position information, providing visual guidance for the movement and positioning of the device.

[0006] Furthermore, the movable device includes a connecting shell, the bottom of which is provided with several traveling wheels. The traveling wheels are used to move along the annular direction of the nut on the tightening surface of the top cover nut. The traveling wheels adopt a straddle structure, so that the main body of the wheel crosses over the nut during movement, and the rollers are located on the side of the nut, away from the edge of the top cover, which effectively reduces the impact on the existing structure and avoids equipment damage caused by clamping the edge of the nut. The connecting shell is provided with a control unit for receiving detection signals from the vision camera and controlling the movement of the device and the pre-tightening action of the nut.

[0007] Furthermore, the connecting shell adopts a split hinged structure, including a connecting plate, and the fastening mechanism, traveling wheels, control unit and vision camera are all connected to the connecting plate; the connecting plate is provided with a protective shell to protect the internal electrical and hydraulic components and prevent the corrosion of dust and oil during operation.

[0008] Furthermore, the connecting plate includes two first connecting plates, one second connecting plate, two third connecting plates, and several movable sleeves. The two first connecting plates connect to the walking wheels, with one end connected to the vision camera and the other end having a connecting groove. The second connecting plate is located between the two first connecting plates and connects to the fastening mechanism; both ends of the second connecting plate have connecting grooves. The two third connecting plates are located between the second and first connecting plates, with both ends inserted into the corresponding connecting grooves. One third connecting plate connects to the control unit, and the other third connecting plate connects to the drive component of the fastening mechanism. The several movable sleeves pass through the connection points between the third and second connecting plates, and between the third and first connecting plates, forming a hinge structure between the third and second connecting plates and between the first and third connecting plates. Bolts are axially threaded through the movable sleeves, and the bolts are connected and fixed by matching washers and nuts, with the diameter of the washers larger than the diameter of the movable sleeves to ensure the stability of the hinge structure. This hinged structure allows the connecting shell to adapt to the annular arc profile of the top cover. When moving along the annular top cover, the connecting plates can rotate relative to each other to adapt to arc working surfaces with different curvatures, solving the problem that traditional rigid structures cannot adapt to arc spaces.

[0009] Furthermore, the traveling wheel includes a wheel frame connected to the connecting shell, a wheel seat at the bottom of the wheel frame, and rollers on both sides of the wheel seat. During movement, the wheel seat passes over the nut on the top cover, while the rollers on both sides roll along the sides of the nut to avoid interference with the nut. A first motor is housed within the wheel frame, and the output shaft of the first motor has a drive shaft connected to the wheel seat for adjusting the angle of the wheel seat to match the traveling trajectory of the curved top cover. Several magnets are provided on the outer circumference of the rollers for adsorption onto the metal surface of the top cover, ensuring the attractive force of the traveling wheel and preventing the device from slipping. A dual-output shaft motor is housed within the wheel seat, and the output shaft of the dual-output shaft motor is connected to the rollers on both sides for driving the rollers to rotate. Alternatively, the rollers can directly use hub motors to simplify the structure and improve driving efficiency.

[0010] Furthermore, the fastening mechanism includes a lifting mechanism and an oil pump located on the connecting shell. The bottom of the lifting mechanism is equipped with a hydraulic torque wrench, which is connected to the oil pump through an oil supply pipe to provide high-pressure hydraulic oil to the hydraulic torque wrench and achieve high torque output. The output end of the hydraulic torque wrench is equipped with a turning sleeve, which is adapted to the nut on the top cover and is used to drive the nut to rotate to complete the pre-tightening.

[0011] Furthermore, the lifting mechanism includes several guide rods connected to the connecting shell. The bottom end of each guide rod has a base plate, which is an annular plate. A movable plate is slidably connected to each guide rod, and the hydraulic torque wrench is fixedly mounted on the movable plate. A connecting sleeve is provided on the movable plate, and a second motor is provided on the connecting shell. The output shaft of the second motor has a threaded rod, which passes through the connecting sleeve and is threadedly connected to it. The end of the threaded rod is rotatably connected to the base plate. When the second motor rotates, the threaded rod can drive the movable plate to rise and fall along the guide rods, thereby realizing the lifting and lowering action of the hydraulic torque wrench. A stabilizing sleeve is provided at the bottom of the movable plate, and the stabilizing sleeve is fitted over the outside of the turning sleeve. The turning sleeve and the stabilizing sleeve are rotatably connected. The bottom surface of the turning sleeve is higher than the bottom surface of the stabilizing sleeve, so that the stabilizing sleeve contacts the top cover surface first during lifting and lowering. A magnet is provided at the bottom of the stabilizing sleeve for adsorption onto the top cover surface, achieving positioning and stability before pre-tightening. The diameter of the stabilizing sleeve is smaller than the inner diameter of the base plate to ensure no interference occurs during lifting and lowering.

[0012] Furthermore, the sidewall of the connecting shell is provided with a driving mechanism, which is used to drive the connecting shell to move along the sidewall of the top cover, cooperating with the traveling wheels on the top surface to achieve stable bidirectional driving; the driving mechanism includes two motor seats respectively located at both ends of the connecting shell, and a third motor is provided on the motor seat. The third motor is a hub motor with a gear ring on its outer circumference; the two third motors are connected by a traveling belt, which extends out of the connecting shell to fit against the sidewall of the top cover and move along the sidewall of the top cover; the inner side of the traveling belt is provided with a tooth groove that matches the gear ring to ensure the stability of the transmission and prevent slippage.

[0013] Furthermore, the connecting shell is also equipped with a stabilizing component, which is used to keep the walking belt always close to the side wall of the top cover and prevent the belt from detaching from the side wall during movement. The stabilizing component includes a rotating column, the bottom of which is equipped with a rotating shaft, which is rotatably connected to the connecting shell through a bearing. The outer periphery of the rotating column is equipped with transmission teeth, which are adapted to the tooth grooves of the walking belt to ensure that the rotating column can rotate synchronously with the belt. The inside of the transmission teeth is equipped with a magnet, which is a ring magnet, sleeved on the outside of the rotating column and radially magnetized, for adsorbing onto the metal side wall of the top cover. The magnetic force presses the walking belt tightly against the side wall to ensure the stability of movement.

[0014] The present invention also provides a method for using the above-mentioned automatic nut pre-tightening device suitable for confined spaces in the top cover, comprising the following steps: S1. Place the automatic nut pre-tightening device on the nut side of the top cover. The device is attracted to the top surface and side wall of the top cover by the magnets of the traveling wheels and the stabilizing parts, thus completing the initial positioning. S2. The visual cameras set at both ends of the automatic nut pre-tightening device collect the nut arrangement information on the surface of the top cover. The control unit processes the collected images and identifies the position coordinates of all nuts. S3. The control unit generates the travel route of the device and the corresponding stopping position of each nut based on the identified nut arrangement information, and plans the optimal pre-tightening sequence to ensure that the top cover is subjected to uniform force. S4. The automatic nut pre-tightening device moves along the generated travel path with the cooperation of the traveling wheels and the drive mechanism, and stops at the stopping position corresponding to the first nut. S5. After stopping, the lifting mechanism of the fastening mechanism drives the hydraulic torque wrench to descend. The stabilizing sleeve first contacts the surface of the top cover and is positioned by magnetic attraction. Then, the tightening sleeve is aligned with the nut, and the hydraulic torque wrench works to drive the tightening sleeve to rotate and pre-tighten the nut until the set pre-tightening torque is reached. S6. After a single nut is pre-tightened, the lifting mechanism drives the hydraulic torque wrench to reset. Then, repeat steps S4-S5 to pre-tighten all nuts in the planned order until all nuts are pre-tightened.

[0015] This invention provides an automatic nut pre-tightening device suitable for confined spaces in top covers and its usage method. By adopting the above solution, the following beneficial effects are achieved: This invention adopts a hinged connecting shell structure, in which the connecting plates can rotate relative to each other, and can adapt to the annular arc contour of the top cover. This solves the problem that traditional rigid automated equipment cannot adapt to arc-shaped working spaces, and can adapt to the top cover operation requirements of different specifications of hydro turbine generator sets.

[0016] The wheels adopt a straddle design, which allows them to pass over the nut when moving. The rollers roll along the side of the nut, eliminating the need for clamping to connect with the nut's fixed surface and avoiding impact on existing structures, thus enhancing adaptability.

[0017] The system uses vision cameras at both ends to automatically identify and locate the position of the nuts. Combined with image processing technology, it achieves high positioning accuracy, accurately identifies the position of each nut, automatically plans the travel route, and realizes continuous automated operation without the need for manual teaching.

[0018] It can automatically complete the continuous pre-tightening of hundreds of nuts, improving the work efficiency by more than 3 times compared with manual operation, and significantly shortening the installation and maintenance cycle of the unit; at the same time, the pre-tightening torque of the hydraulic torque wrench is precise and controllable, and the pre-tightening torque of all nuts is highly consistent, effectively ensuring the installation quality and operational safety of the top cover.

[0019] The device is stably attached to the top cover by a magnetic structure, eliminating the need for manual entry into the narrow annular gap for operation. This completely eliminates safety hazards such as bumps and squeezing that occur during manual operation, ensuring the safety of the workers. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the internal structure of the present invention; Figure 3 This is an enlarged structural schematic diagram of the fastening mechanism of the present invention; Figure 4 This is an enlarged structural schematic diagram of the walking wheel of the present invention; Figure 5 This is a cross-sectional view of the fastening mechanism of the present invention; Figure 6 This is a cross-sectional view of the stabilizer part of this device; Figure 7 This is a top view of the present invention; Figure 8 This is an enlarged structural schematic diagram of the walking wheel of the present invention; Figure 9This is a schematic diagram of the connecting plate of the present invention.

[0021] In the picture: Top cover connecting seat 101, top cover connecting ring 102, tightened nut 103, connecting plate 201, first connecting plate 211, second connecting plate 212, third connecting plate 213, connecting groove 214, movable sleeve 215, bolt 216, protective shell 202, vision camera 3, traveling wheel 4, wheel frame 401, wheel seat 402, roller 403, first motor 404, drive shaft 405, fastening mechanism 5, oil pump 501, guide rod 502, movable plate 503, connecting sleeve 504, base plate 505, second motor 506, threaded rod 507, oil pipe 508, hydraulic torque wrench 509, tightening sleeve 510, stabilizing sleeve 511, drive mechanism 6, third motor 601, traveling belt 602, motor seat 603, stabilizing component 7, rotating column 701, rotating shaft 702, bearing 703, transmission gear 704, magnet 705, control unit 8. Detailed Implementation

[0022] Example 1: like Figure 1-9 As shown, the automatic nut pre-tightening device for the narrow space of the top cover in this embodiment is applied to the top cover operation scenario of a hydro-generator set. The top cover edge is provided with a top cover connecting ring 102, and the hydro-generator set is provided with a top cover connecting seat 101 connected to the top cover connecting ring 102. The top cover connecting seat 101 and the top cover connecting ring 102 are fixed by matching bolts and nuts. The nut is arranged circumferentially along the top cover and is the nut to be tightened 103. The working space is the surface of the top cover where the nut is located, generally with only a narrow gap. The aforementioned top cover connecting seat 101, top cover connecting ring 102, and nut to be tightened 103 are all common structures for existing top cover connections. The nut pre-tightened by the fastening mechanism 5 is the nut to be tightened 103. Figure 1 As shown, the automatic nut pre-tightening device of this application, which is suitable for the narrow space of the top cover, moves only on the top cover connecting ring 102 to tighten the nut 103 being tightened.

[0023] Specifically, the automatic nut pre-tightening device suitable for confined spaces in the top cover includes a movable device that can move along the annular surface of the top cover in the direction of nut arrangement. The main body of the movable device is a connecting shell, and a protective shell 202 is provided on the outside of the connecting shell to protect the internal components. A vision camera 3 is provided at each end of the connecting shell. The vision camera 3 is preferably a high-precision industrial camera, equipped with an LED supplementary light source, which can clearly capture images in dimly lit working environments to detect the position of the nuts and provide visual guidance for the device.

[0024] Two wheels 4 are located at the bottom of the connecting shell, one at each end. These wheels support the entire device and move it along the top surface of the top cover. Specifically, each wheel 4 includes a wheel frame 401 fixed to the bottom of the connecting shell. A wheel seat 402 is located at the bottom of the wheel frame 401, with a roller 403 on each side of the wheel seat 402. When the device moves, the wheel seat 402 passes over the nut on the top cover, while the rollers 403 roll along the side of the nut on the surface of the top cover, preventing interference between the wheels 4 and the nut and avoiding mutual influence with the nut or surrounding equipment. A first motor 404, preferably a stepper motor, is housed within the wheel frame 401. The first motor 404 is connected and controlled using existing methods. The output shaft of the first motor 404 is connected to a drive shaft 405, which is connected to the wheel seat 402. The first motor 404 can drive the wheel seat 402 to rotate by a certain angle, thereby adjusting the direction of the rollers 403 to match the arc-shaped travel trajectory of the top cover. Several strong magnets are embedded on the outer circumference of the roller 403 to attract it to the metal surface of the top cover, providing an attractive force and preventing the device from slipping off.

[0025] The wheel base 402 is equipped with a dual-output-shaft stepper motor, that is, a stepper motor with output shafts on both sides. It is connected and controlled in the existing way. The two output shafts of the dual-output-shaft motor are respectively connected to the rollers 403 on both sides to drive the rollers 403 to rotate, thereby driving the device to move. In an optional embodiment, the roller 403 can also be preferably a hub motor, which simplifies the transmission structure and improves driving efficiency.

[0026] The side wall of the connecting shell is also equipped with a drive mechanism 6, which drives the device to move along the side wall of the top cover. This mechanism works in conjunction with the traveling wheels 4 on the top surface to achieve dual drive. Specifically, the drive mechanism 6 includes two motor mounts 603, respectively located at both ends of the connecting shell. Each motor mount 603 is equipped with a third motor 601, preferably a hub motor, which is configured and controlled using existing methods. A gear ring is connected to its outer circumference. The two third motors 601 are connected by a traveling belt 602, a portion of which extends out of the connecting shell to fit against the side wall of the top cover. The inner side of the traveling belt 602 has toothed grooves that mate with the gear ring, allowing the third motors 601 to drive the traveling belt 602 to rotate via the gear ring. This, in turn, drives the device to move through the friction between the traveling belt 602 and the side wall.

[0027] To ensure that the travel belt 602 remains firmly against the side wall of the top cover, a stabilizing component 7 is also provided on the connecting shell. The stabilizing component 7 includes a rotating column 701, with a rotating shaft 702 at its bottom. The rotating shaft 702 is rotatably connected to the connecting shell via a bearing 703. The outer circumference of the rotating column 701 has transmission teeth 704, which are adapted to the tooth grooves of the travel belt 602, allowing the rotating column 701 to rotate synchronously with the travel belt 602. An annular magnet 705 is fitted around the outside of the rotating column 701. This magnet 705 is preferably radially magnetized, generating a radial magnetic force that attracts the metal side wall of the top cover. This magnetic force presses the travel belt 602 firmly against the side wall of the top cover, preventing the belt from detaching and ensuring stable movement.

[0028] The connecting housing has a fastening mechanism 5 inside for pre-tightening the nut. Specifically, the fastening mechanism 5 includes an oil pump 501 and a lifting mechanism. The lifting mechanism includes four guide rods 502, the top of which is fixed to the connecting housing, and the bottom of which is fixed to an annular base plate 505. A movable plate 503 is slidably connected to the guide rod 502, and the movable plate 503 can slide up and down along the guide rod 502. A connecting sleeve 504 is fixed to the movable plate 503. A second motor 506 is fixed to the connecting housing. The second motor 506 is preferably a stepper motor, connected and controlled in an existing manner. The output shaft of the second motor 506 is connected to a threaded rod 507, which passes through the connecting sleeve 504 and is threadedly connected to the connecting sleeve 504. The bottom of the threaded rod 507 is rotatably connected to the base plate 505. When the second motor 506 rotates, it drives the threaded rod 507 to rotate, thereby driving the movable plate 503 to rise and fall along the guide rod 502 through threaded transmission.

[0029] A hydraulic torque wrench 509 is fixed to the bottom of the movable plate 503. The hydraulic torque wrench 509 is connected to the oil pump 501 via an oil supply pipe 508. The oil pump 501 provides high-pressure hydraulic oil to the hydraulic torque wrench 509, driving it to output high torque. The oil pump 501 and the hydraulic torque wrench 509 are compatible and can be connected and controlled using existing methods. The torque regulation method can also use existing technology. If needed, a compatible hydraulic tank is provided inside the connecting housing to provide the required hydraulic oil for the oil pump 501 to supply to the hydraulic torque wrench 509.

[0030] The output end of the hydraulic torque wrench 509 is equipped with a tightening sleeve 510. The inner contour of the tightening sleeve 510 is adapted to the nut on the top cover, allowing it to engage with the nut and drive it to rotate. A stabilizing sleeve 511 is also provided at the bottom of the movable plate 503. The stabilizing sleeve 511 is fitted over the tightening sleeve 510, and the tightening sleeve 510 and stabilizing sleeve 511 are rotatably connected by a bearing. The bottom surface of the stabilizing sleeve 511 is higher than the bottom surface of the tightening sleeve 510, so that when the movable plate 503 descends, the stabilizing sleeve 511 will contact the surface of the top cover first. A magnet is embedded in the bottom of the stabilizing sleeve 511, allowing it to adhere to the surface of the top cover, achieving positioning and stabilization before pre-tightening and preventing the device from shaking during pre-tightening. The diameter of the stabilizing sleeve 511 is smaller than the inner diameter of the base plate 505, ensuring that it will not interfere with the base plate during lifting and lowering.

[0031] The connecting shell is preferably a split hinged connecting plate structure. Specifically, the connecting plate includes two first connecting plates 211, one second connecting plate 212, and two third connecting plates 213. The two first connecting plates 211 are located on the outermost side and are used to connect the walking wheels 4. The outer end of the first connecting plate 211 is connected to the vision camera 3, and the inner end has a connecting groove 214. The second connecting plate 212 is located in the middle position and is used to connect the fastening mechanism 5. Both ends of the second connecting plate 212 also have connecting grooves 214. The two third connecting plates 213 are located on both sides of the second connecting plate 212, between the first connecting plates 211 and the second connecting plate 212. The two ends of the third connecting plates 213 are respectively inserted into the connecting grooves 214 of the first connecting plates 211 and the second connecting plates 212. A control unit 8 is fixedly installed on one of the third connecting plates 213, and a driving component such as an oil pump 501 of the fastening mechanism 5 is fixedly installed on the other third connecting plate 213.

[0032] At the joints of each connecting plate, a movable sleeve 215 is inserted. The movable sleeve 215 passes through the joint between two connecting plates, and then a bolt 216 is inserted along the axial direction of the movable sleeve 215. The end of the bolt 216 is locked by a washer and a nut. The diameter of the washer is larger than the diameter of the movable sleeve 215, allowing the two connecting plates to rotate relative to each other around the movable sleeve 215, forming a hinged structure. Through the hinged structure, the entire connecting shell can adapt to the arc-shaped contour of the top cover. When the device moves on the annular top cover, the connecting plates can rotate relative to each other, thereby adapting to different curvatures and solving the problem that traditional rigid structures cannot adapt to arc-shaped spaces.

[0033] The control unit 8 is the core of the entire device, preferably an industrial-grade controller, with built-in image processing, motion control, and torque control modules. The control unit 8 is electrically connected to the vision camera 3, the drive motor of the walking wheel 4, the third motor 601 of the drive mechanism 6, the second motor 506 of the fastening mechanism 5, the oil pump 501, and the hydraulic torque wrench 509. It can receive images captured by the vision camera 3, process and identify the position of the nut, and then control each actuator to complete actions such as movement, positioning, and pre-tightening.

[0034] Furthermore, a battery is installed inside the connecting housing to provide the power required by the device.

[0035] Example 2: A method for using an automatic nut pre-tightening device suitable for confined spaces in a top cover includes the following steps: S1. The operator places the entire device on the surface where the nut is located on the top cover. After the device is placed, the magnet on the roller of the traveling wheel 4 will be attracted to the top surface of the top cover, and at the same time, the magnet 705 of the stabilizing component 7 will be attracted to the side wall of the top cover, thus fixing the entire device stably on the top cover and preventing it from slipping off, completing the initial installation.

[0036] S2. The vision cameras 3 at both ends of the device start working and collect images of the top cover surface. The image processing module of the control unit 8 processes the images and identifies the position coordinates of all nuts through algorithms such as edge detection and centroid recognition, and obtains the arrangement information of the nuts.

[0037] S3, the control unit 8 generates the travel route of the device and the corresponding stopping position of each nut based on the identified nut position, and plans the optimal pre-tightening sequence, preferably a symmetrical pre-tightening sequence, to ensure that the top cover is subjected to uniform force during the pre-tightening process and avoid deformation caused by uneven force.

[0038] S4. The device begins to move along the planned route. The rollers 403 of the traveling wheel 4 rotate, and at the same time, the third motor 601 of the drive mechanism 6 drives the traveling belt 602 to rotate. The two work together to move the entire device along the annular surface of the top cover. The hinged connecting shell can adapt to the arc-shaped trajectory to ensure smooth movement. When the device moves to the stopping position of the first nut, it stops moving.

[0039] S5. The fastening mechanism 5 starts working, the second motor 506 rotates, driving the movable plate 503 to descend along the guide rod 502. First, the stabilizing sleeve 511 contacts the surface of the top cover, and the magnet at the bottom of the stabilizing sleeve 511 is attracted to the top cover to complete the positioning. At the same time, the sleeve 510 is turned to align with the nut below and is engaged with the nut.

[0040] The existing method is used to control the operation of the oil pump 501 to provide high-pressure oil to the hydraulic torque wrench 509. The hydraulic torque wrench 509 drives the tightening sleeve 510 to rotate and pre-tighten the nut. The torque control module monitors the pre-tightening torque in real time. When the set pre-tightening torque is reached, the hydraulic torque wrench 509 stops working, completing the pre-tightening of a single nut.

[0041] S6. After pre-tightening is completed, the second motor 506 reverses, driving the movable plate 503 to rise and return to its initial position. Then the device continues to move to the position of the next nut and repeats the above pre-tightening action until all nuts are pre-tightened. The entire operation process is fully automatic and requires no manual intervention.

[0042] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. An automatic nut pre-tightening device suitable for confined spaces in a top cover, characterized by: Includes a movable device located on the surface of the top cover nut, the movable device moving in the direction in which the nut is set; The movable device is equipped with a fastening mechanism (5) for pre-tightening the nut; The device is equipped with several vision cameras (3) for detecting the position of the nut.

2. The automatic nut pre-tightening device suitable for confined spaces in a top cover according to claim 1, characterized in that: The movable device includes a connecting shell, which is provided with several traveling wheels (4). The traveling wheels (4) are used to move along the direction set by the nut on the tightening surface of the top cover nut. The wheels (4) are located away from the edge of the top cover to reduce the impact on the existing structure; The connecting housing contains a control unit (8) for receiving signals, controlling movement, and pre-tightening the nut.

3. The automatic nut pre-tightening device suitable for confined spaces in a top cover according to claim 2, characterized in that: The connecting shell includes a connecting plate (201), and the fastening mechanism (5), the walking wheel (4), the control unit (8) and the vision camera (3) are all connected to the connecting plate (201); The connecting plate (201) is provided with a protective shell (202).

4. The automatic nut pre-tightening device suitable for confined spaces in a top cover according to claim 3, characterized in that: The connecting plate (201) includes two first connecting plates (211), a second connecting plate (212), two third connecting plates (213), and several movable sleeves (215), wherein: Two first connecting plates (211) are used to connect the walking wheel (4), and one end is connected to the vision camera (3), and the other end is provided with a connecting groove (214). The second connecting plate (212) is located between the two first connecting plates (211) and is used to connect the fastening mechanism (5). Both ends of the second connecting plate (212) are provided with connecting grooves (214). Two third connecting plates (213) are located between the second connecting plate (212) and the first connecting plate (211), and both ends are inserted into the interior of the connecting groove (214); one of the third connecting plates (213) is connected to the control unit (8), and the other third connecting plate (213) is connected to the drive component of the fastening mechanism (5); Several movable sleeves (215) pass through the connection between the third connecting plate (213) and the second connecting plate (212) or through the connection between the third connecting plate (213) and the first connecting plate (211), so that the third connecting plate (213) is hinged to both the second connecting plate (212) and the first connecting plate (211); The movable sleeve (215) is axially fitted with bolts (216), which are connected and fixed by matching washers and nuts. The diameter of the washers is larger than that of the movable sleeve (215).

5. The automatic nut pre-tightening device suitable for confined spaces in a top cover according to claim 2, characterized in that: The walking wheel (4) includes a wheel frame (401) connected to the connecting shell. The bottom of the wheel frame (401) is provided with a wheel seat (402), and rollers (403) are provided on both sides of the wheel seat (402). When moving, the wheel seat (402) passes over the nut of the top cover, and the roller (403) passes over the side of the nut of the top cover; The wheel frame (401) is equipped with a first motor (404), and the output shaft of the first motor (404) is equipped with a transmission shaft (405), which is connected to the wheel seat (402); The outer circumferential surface of the roller (403) is provided with several magnets; The wheel seat (402) is equipped with a dual-output shaft motor, and the output shaft of the dual-output shaft motor is connected to the roller (403); or The roller (403) is a hub motor.

6. The automatic nut pre-tightening device suitable for confined spaces in a top cover according to claim 2, characterized in that: The fastening mechanism (5) includes a lifting mechanism and an oil pump (501) located in the connecting shell. The lifting mechanism is equipped with a hydraulic torque wrench (509), and the hydraulic torque wrench (509) is connected to the oil pump (501) through an oil supply pipe (508). The output end of the hydraulic torque wrench (509) is provided with a tightening sleeve (510), which is adapted to the nut of the top cover.

7. The automatic nut pre-tightening device suitable for confined spaces in a top cover according to claim 6, characterized in that: The lifting mechanism includes several guide rods (502) connected to the connecting shell. The bottom end of the guide rods (502) is provided with a base plate (505), which is an annular plate. The guide rod (502) is slidably connected to the movable plate (503), and the hydraulic torque wrench (509) is connected to the movable plate (503); The movable plate (503) is provided with a connecting sleeve (504), the connecting shell is provided with a second motor (506), the output shaft of the second motor (506) is provided with a threaded rod (507), the threaded rod (507) passes through the connecting sleeve (504) and is threadedly connected to the connecting sleeve (504), and the end of the threaded rod (507) is rotatably connected to the base plate (505); The bottom of the movable plate (503) is provided with a stabilizing sleeve (511), which is sleeved on the outside of the rotating sleeve (510). The rotating sleeve (510) and the stabilizing sleeve (511) are rotatably connected. The bottom surface of the rotating sleeve (510) is higher than the bottom surface of the stabilizing sleeve (511); the bottom of the stabilizing sleeve (511) is provided with a magnet; The diameter of the stabilizing sleeve (511) is smaller than the inner diameter of the base plate (505).

8. The automatic nut pre-tightening device suitable for confined spaces in a top cover according to claims 2-7, characterized in that: The connecting shell is provided with a driving mechanism (6), which is used to drive the connecting shell to move along the side wall of the top cover; The drive structure (6) includes two motor mounts (603) respectively located at both ends of the connecting shell. The motor mounts (603) are equipped with a third motor (601). The third motor (601) is a hub motor. The outer circumference of the third motor (601) is equipped with a gear ring. Two third motors (601) are connected by a walking belt (602). The walking belt (602) extends out of the connecting shell to fit against the side wall of the top cover and move along the side wall of the top cover. The inner side of the walking belt (602) is provided with a tooth groove that matches the tooth ring.

9. The automatic nut pre-tightening device for a confined space in a top cover according to claim 8, characterized in that: The connecting shell is provided with a stabilizing element (7), which is used to make the walking belt (602) stick to the side wall of the top cover; The stabilizer (7) includes a rotating column (701), and a rotating shaft (702) is provided at the bottom of the rotating column (701). The rotating shaft (702) is rotatably connected to the connecting housing via a bearing (703); The rotating column (701) is provided with transmission teeth (704), which are adapted to the tooth grooves of the traveling belt (602); A magnet (705) is provided inside the transmission gear (704); The magnet (705) is a ring magnet, and the magnet (705) is sleeved on the outside of the rotating column (701); The magnet (705) is radially magnetized.

10. A method of using the automatic nut pre-tightening device for confined spaces in a top cover as described in any one of claims 1-9, characterized in that: Includes the following steps: S1. Place the automatic nut preload device on the nut side of the top cover; S2. Visual cameras (3) are installed at both ends of the automatic nut pre-tightening device to collect nut arrangement information; S3. Generate the travel route and stopping position based on the nut arrangement information; S4. The automatic nut preload device moves along the travel path and stops at the stopping position; S5. When stopping, the automatic nut preload device preloads the nut; S6. Pre-tightening is complete. Repeat S4-S5 until all nuts are pre-tightened.

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