A tightening device and method

Abstract

The application discloses a tightening device and a tightening method, which are suitable for open-type circuit breaker arc-extinguishing chamber porcelain bottle flange assembly. A vertical moving assembly is arranged on a device frame to drive a first mounting plate to move up and down. The first mounting plate is provided with a horizontal moving assembly to drive a second mounting plate to move transversely. The second mounting plate is loaded with a right-angle tightening gun. A bolt sleeve with a magnetic element is connected to the gun head through a biasing head. A rotating cylinder, a bearing seat, a rotating shaft and a nut sleeve capable of being turned by 180 degrees are arranged at the bottom of the frame. The nut sleeve is also provided with a magnetic element, and the two can be coaxially aligned. The vertical moving assembly is provided with a buffer limiting structure. A spring is arranged in the biasing head to provide a 5-8 N compression force to compensate for assembly deviation. The second mounting plate is provided with a visual sensor to realize hole position recognition and positioning. The application is compatible with single-side bolt locking and bolt and nut double-side locking two processes. The application has the advantages of simple structure, small occupation, high assembly fault tolerance, reduced equipment cost and guaranteed arc-extinguishing chamber batch assembly locking quality.

Description

Technical Field

[0001] This invention relates to the field of threaded fastening assembly technology, and discloses a tightening device and method. Background Technology

[0002] In industrial settings such as machining, automotive parts assembly, and home appliance manufacturing, thread tightening of bolts and nuts is a high-frequency, fundamental process. Currently, most conventional tightening equipment has a single-sided tightening structure, which can only drive the bolt into place from one side of the workpiece. The nut needs to be pre-placed manually or positioned to the other side of the workpiece by an independent feeding mechanism. This not only makes the operation process cumbersome and the assembly efficiency low, but also makes it easy for positioning deviations to occur during manual placement, resulting in problems such as stripped threads, misaligned locking, and thread damage during tightening.

[0003] In some existing double-sided locking devices, the nut positioning mechanism is mostly a fixed structure, which cannot take into account the dual functions of nut feeding and locking support. The feeding path is complicated and the equipment layout is cumbersome. At the same time, the bolt lacks a position compensation structure during feeding and tightening. When there is a machining deviation in the workpiece hole or an error in the equipment positioning, bolt jamming and thread breakage are likely to occur. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems of limited functionality, inconvenient material feeding, and poor positioning accuracy of existing tightening equipment, and to provide a tightening device and method.

[0005] To achieve the above-mentioned technical effects, the technical solution adopted by the present invention is as follows: a tightening device, comprising a frame, a first mounting plate movably mounted on the frame, and a vertical moving component on the frame for driving the first mounting plate to move along the height direction of the frame; a second mounting plate movably mounted on the first mounting plate, and a horizontal moving component on the first mounting plate for driving the second mounting plate to move along the length direction of the frame; a tightening gun connected to the second mounting plate via the mounting plate, the output end of the tightening gun connected to a bolt sleeve, the bolt sleeve having a magnetic attraction element for attracting bolts; a rotary cylinder and a bearing seat mounted at the bottom of the frame, the output end of the rotary cylinder connected to a rotating shaft, the rotating shaft rotatably mounted on the bearing seat, a sleeve bracket connected to the rotating shaft, a nut sleeve connected to the sleeve bracket, the nut sleeve being coaxially arranged with the bolt sleeve, and the nut sleeve having a magnetic attraction element for attracting nuts.

[0006] In a preferred embodiment, the vertical moving component includes a first guide rail and a first cylinder, both of which are mounted on the frame. The first mounting plate is connected to the slider of the first guide rail, and the output end of the first cylinder is connected to the first mounting plate.

[0007] In a preferred embodiment, the horizontal moving component includes a second guide rail and a second cylinder, both of which are mounted on the first mounting plate. The second mounting plate is connected to the slider of the second guide rail, and the output end of the second cylinder is connected to the second mounting plate.

[0008] As a preferred embodiment, the tightening gun is a right-angle tightening gun, and an offset head is connected to the end of the tightening gun. The offset head has a built-in spring guide structure, which is used to provide clamping force to the bolt during the tightening process and compensate for positional deviation.

[0009] As a preferred embodiment, the vertical moving component is provided with buffers and limiters on both sides of its travel to limit the range of movement of the first mounting plate and mitigate impact.

[0010] In a preferred embodiment, the rotating shaft passes through the bearing housing, and the rotary cylinder drives the rotating shaft to rotate 180° along the bearing housing, so that the nut sleeve switches between a downward material-taking state and an upward locking state.

[0011] In a preferred embodiment, the second mounting plate is provided with a vision sensor, the acquisition end of which faces downwards from the bolt sleeve, for identifying the position of the connection hole of the workpiece to be assembled and providing feedback to adjust the movement displacement of the vertical moving component and the horizontal moving component.

[0012] The present invention also provides a tightening method for a tightening device, including a unilateral locking method, comprising the following steps: S1. The vertical moving component is in the upper limit position, the horizontal moving component is in the alignment position, and the nut sleeve is facing upward; S2. The vertical moving component drives the bolt sleeve to descend to the standard parts tray, and then rises back after the bolt and flat washer are attracted by the magnetic component. S3. Align the bolt axis with the connecting hole axis, the vertical moving component drives the bolt sleeve to descend, and the tightening gun rotates at low speed to guide the bolt through the through hole; S4. Tighten the bolts with the tightening gun at the set speed, and collect the torque and torsion angle values ​​in real time. Stop when the torque reaches the preset threshold and the angle is within the allowable range. S5. The vertical moving component drives the tightening gun component to rise, and the bolt sleeve separates from the bolt.

[0013] As a preferred embodiment, the tightening method further includes a double-sided locking method, which comprises the following steps in sequence: S1. The rotary cylinder drives the nut sleeve to flip downwards, and the vertical moving component drives the nut sleeve to descend to the material tray, adsorb the nut and flat washer, then rises and flips upwards. S2. The horizontal moving component moves the tightening gun component to the clearance position, and resets after the bolt is picked up, so that the bolt sleeve and nut sleeve are coaxially aligned. S3. Align the axis of the nut sleeve with the connecting hole, and use the vertical moving component to drive the bolt sleeve to descend, so that the bolt passes through the through hole and fits with the nut; S4. Tighten by rotating the tightening gun, monitor the torque and angle in real time, and stop when the preset conditions are met.

[0014] As a preferred embodiment, during the tightening process, the spring guide structure of the offset head of the tightening gun provides a clamping force of 5-8N to the bolt to compensate for positional deviations during assembly.

[0015] Compared with existing technologies, this invention, through a 180° rotatable nut sleeve structure, can achieve both conventional single-sided bolt tightening operations and double-sided bolt and nut locking operations. Both the bolt sleeve and nut sleeve have built-in magnetic components, allowing for direct pickup of bolts, nuts, and flat washers via magnetic attraction. A two-dimensional moving platform composed of vertical and horizontal moving components, combined with hole position recognition feedback from a vision sensor, can be used for alignment calibration. Simultaneously, an offset head with a spring-guided structure is provided at the front end of the tightening gun to provide stable clamping force during tightening, compensating for workpiece hole machining errors and equipment positioning deviations, and preventing thread damage and jamming. The vertical moving component is equipped with a buffer and limiter to mitigate motion impact and reduce operating noise. Attached Figure Description

[0016] Figure 1 This is an overall schematic diagram of the present invention; Figure 2 This is a schematic diagram showing the connection between the horizontal moving component and the tightening gun component of the present invention; Figure 3 This is a schematic diagram of the connection between the rotary cylinder and the nut sleeve of the present invention; Figure 4 This is a structural diagram of the connection between the ceramic insulator and the flange in the arc-extinguishing chamber of the present invention; Figure label: 1. Vertical moving component; 11. Frame; 12. First guide rail; 13. First mounting plate; 14. First cylinder; 2. Horizontal moving assembly; 21. Second guide rail; 22. Second mounting plate; 23. Second cylinder; 31. Mounting base; 32. Tightening gun; 33. Offset head; 34. Bolt sleeve; 41. Rotary cylinder; 42. Bearing housing; 43. Shaft; 44. Sleeve bracket; 45. Nut sleeve; 5. Stationary flange; 6. Porcelain insulator for arc extinguishing chamber; 61. Static flange of porcelain insulator; 62. Dynamic flange of porcelain insulator. 7. Moving side flange. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings. However, this should not be construed as limiting the scope of the above-described subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0018] refer to Figure 1 Example 1: The tightening device disclosed in this invention is mainly used for the automatic tightening of bolts and nuts on mechanical parts. It includes: a frame 11, which serves as the supporting base for the entire device, constructed by welding profiles or assembling with bolts, forming an overall vertical frame structure. A vertical moving component 1 is installed on the vertical side wall of the frame 11. The vertical moving component 1 includes a first guide rail 12 and a first cylinder 14. The first guide rail 12 is vertically arranged along the height direction of the frame 11. A first mounting plate 13 is fixedly connected to the slider of the first guide rail 12. The cylinder body of the first cylinder 14 is fixed to the top of the frame 11, and its piston rod output end is connected to the upper end of the first mounting plate 13. The extension and retraction of the first cylinder 14 drives the first mounting plate 13 to reciprocate vertically along the first guide rail 12. Buffers and limiters are provided at both the upper and lower ends of the stroke of the vertical moving component 1. The limiters are used to limit the upper and lower limit positions of the first mounting plate 13 to ensure positioning accuracy. The buffer adopts a hydraulic or polyurethane buffer structure to absorb the impact when the first mounting plate 13 is in place, reduce equipment operating noise, and improve the service life of the components.

[0019] refer to Figure 2 A horizontal moving assembly 2 is mounted on the front of the first mounting plate 13. The horizontal moving assembly 2 includes a second guide rail 21 and a second cylinder 23. The second guide rail 21 is arranged horizontally along the length of the frame 11. A second mounting plate 22 is fixedly connected to the slider of the second guide rail 21. The cylinder body of the second cylinder 23 is fixed on the first mounting plate 13, and its piston rod output end is connected to the side of the second mounting plate 22. The extension and retraction of the second cylinder 23 drives the second mounting plate 22 to reciprocate horizontally along the second guide rail 21, thereby driving the tightening gun assembly to adjust its horizontal position and avoid workstations.

[0020] refer to Figure 2A tightening gun 32 is fixed to the second mounting plate 22 via an adapter mounting plate. In this embodiment, the tightening gun 32 is a right-angle tightening gun with its output axis arranged downwards. An offset head 33 is connected to the output end of the tightening gun 32, and a bolt sleeve 34 is installed at the lower end of the offset head 33. The offset head 33 has a built-in spring guide structure, with the spring arranged along the tightening axis. During the bolt feeding and tightening process, the spring is always in a compressed state, which can provide an axial clamping force of 5-8N to the bolt. At the same time, the bolt sleeve 34 is allowed to have a certain radial floating amount, thereby compensating for the machining deviation of the workpiece connecting hole and the equipment positioning error, and avoiding thread damage or jamming caused by hard contact between the bolt and the hole. A magnetic attraction element, specifically a permanent magnet, is embedded in the top of the inner hole of the bolt sleeve 34. When the bolt sleeve 34 is close to the bolt head, it can magnetically attract the bolt and the matching flat washer to prevent the bolt from falling off during movement and feeding.

[0021] A vision sensor is also installed on the second mounting plate 22. The lens of the vision sensor is vertically downward, facing the area below the bolt sleeve 34. During operation, the vision sensor can photograph the surface of the workpiece to be assembled, identify the coordinate position of the connecting hole, and feed back the position deviation signal to the control system. The control system adjusts the movement displacement of the vertical moving component 1 and the horizontal moving component 2 accordingly to achieve precise coaxial alignment of the bolt and the connecting hole, thereby improving assembly accuracy.

[0022] refer to Figure 1 , Figure 3 A nut sleeve flipping assembly is installed on the bottom platform of the frame 11. This assembly includes a rotary cylinder 41, a bearing seat 42, a rotating shaft 43, a sleeve bracket 44, and a nut sleeve 45. The rotary cylinder 41 and the bearing seat 42 are both fixedly installed on the mounting platform at the bottom of the frame 11. The rotating shaft 43 is horizontally inserted into the bearing seat 42 and can rotate freely around its own axis. One end of the rotating shaft 43 is coaxially connected to the output end of the rotary cylinder 41. One end of the sleeve bracket 44 is fixedly sleeved on the rotating shaft 43, and the other end extends outward and is fixedly installed with the nut sleeve 45. The inner hole of the nut sleeve 45 is also fitted with a magnetic element for adsorbing the nut and the flat washer. The rotary cylinder 41 can drive the rotating shaft 43 to reciprocate 180°, which in turn drives the nut sleeve 45 to rotate through the sleeve bracket 44, so that the nut sleeve 45 can switch between the material picking state with the opening facing down and the locking state with the opening facing up. When the nut sleeve 45 is in the upward state, its axis is completely coincident with the axis of the bolt sleeve 34 above, ensuring the coaxiality when locking on both sides.

[0023] refer to Figure 1 , Figure 2 , Figure 4 Example 2: Based on the above-mentioned tightening device, the present invention also provides two tightening methods, namely a single-sided locking method and a double-sided locking method, the specific implementation methods of which are as follows: ① For the single-sided locking assembly process of the moving side flange 62 of the porcelain insulator: The moving side flange 77 has an internal thread, and the moving side flange 62 of the porcelain insulator has a through hole. Only one side needs to be bolted for locking. The steps are as follows: S1. The first cylinder 14 retracts to the upper limit of its stroke, and the second cylinder 23 retracts to the alignment position; the rotary cylinder 41 drives the nut sleeve 45 to maintain an upward posture, and the robot arm carries the whole machine to the standard parts tray for standby.

[0024] S2. The robot arm calibrates the position so that the bolt sleeve 34 is aligned with the bolt on the tray. The first cylinder 14 extends to drive the first mounting plate 13 to descend. The bolt sleeve 34 magnetically attracts the bolt and the flat washer. Then the cylinder retracts and rises back to the upper limit position.

[0025] S3. The robotic arm transfers the device to the arc-extinguishing chamber assembly station. The visual sensor identifies the flange connection hole, and the control system fine-tunes the vertical and horizontal components to make the bolt axis coaxial with the flange through hole and the moving side internal thread hole. The cylinder slowly lowers the tightening gun 32, which rotates at a low speed of 5r / min to guide the bolt through the through hole of the moving side flange 62 of the porcelain insulator, with the thread end fitting the internal thread inlet.

[0026] S4. Tightening gun 32 switches to a working speed of 30r / min to tighten the bolt; the offset head 33 spring continuously provides axial clamping force to prevent thread jamming; the equipment collects torque and torsion angle in real time, and when the torque reaches 32N·m and the torsion angle is in the range of 180°~200°, tightening gun 32 stops immediately.

[0027] S5. The first cylinder 14 retracts and lifts the tightening gun 32 assembly. When the magnetic force of the bolt sleeve 34 is less than the bolt locking preload, the sleeve and bolt automatically separate. The robotic arm carrying the device returns to the material tray, and the cycle is completed to tighten the remaining holes.

[0028] ② Regarding the double-sided locking assembly process for the moving side flange 62 of the porcelain insulator, both the stationary side flange 55 and the stationary side flange 61 of the porcelain insulator have through holes and require bolts and nuts to be tightened on both sides. The steps are as follows: S1. The device completes initialization. The rotary cylinder 41 drives the rotating shaft 43 to rotate 180°, and the nut sleeve 45 flips to face downwards. The robot arm aligns with the nut tray, and the first cylinder 14 lowers the whole machine. The nut sleeve 45 magnetically attracts the nut and the flat washer. After the cylinder is lifted, the rotary cylinder 41 rotates 180° in the opposite direction, and the nut sleeve 45 switches to an upward locking posture.

[0029] S2. The second cylinder 23 extends, pushing the second mounting plate 22 to the avoidance position, and the tightening gun 32 component is horizontally offset to avoid the nut sleeve 45; the robot arm fine adjustment device is aligned with the bolt tray, and the cylinder is lowered to complete the bolt magnetic pickup; after pickup and recovery, the second cylinder 23 retracts and resets to the alignment position, and the bolt sleeve 34 and the nut sleeve 45 are precisely coaxial vertically.

[0030] S3. The robotic arm transfers the device to stationary flange 5, visually calibrates the position of the connection hole, and the upper end face of the nut sleeve 45 is attached to the lower surface of the porcelain bottle stationary flange 61; the first cylinder 14 lowers the tightening gun 32, and the bolt passes through the through hole of stationary flange 5 and porcelain bottle stationary flange 61 from top to bottom, and the threaded end of the bolt is attached to the nut inside the nut sleeve 45.

[0031] S4. Tightening gun 32 drives the bolt to rotate, and nut sleeve 45 restricts the nut's circumferential rotation by magnetic attraction and the sleeve wall, so that the bolt is screwed into the nut and locked; the spring continuously applies clamping force to ensure stable thread engagement; tightening gun 32 stops after the torque and angle simultaneously meet the preset threshold.

[0032] S5. The first cylinder 14 lifts the tightening gun 32, and the bolt sleeve 34 separates from the bolt head; the robot arm moves the whole machine down slightly, and the nut sleeve 45 disengages from the locked nut; all components are reset and return to the material tray area for cyclical operation.

[0033] ③ Control process for switching between two operating conditions After the single-sided locking process is completed, the device maintains the upper limit position, the alignment position, and the nut sleeve 45 facing upwards; the control system receives the switching command, the rotary cylinder 41 first flips the nut sleeve 45 downwards, and at the same time the second cylinder 23 extends to push the tightening gun 32 to the clearance position; the vertical moving component 1 completes the nut pickup and lifting, the rotary cylinder 41 flips the nut sleeve 45 upwards; the second cylinder 23 retracts and resets to the alignment position, and the device enters the double-sided locking ready state.

[0034] After the double-sided locking operation is completed, all mechanisms are reset to the upper limit position; the system issues a switching command, the rotary cylinder 41 adjusts the nut sleeve 45 to be stored upwards, and the second cylinder 23 maintains the alignment position without needing to avoid it; the vertical moving component 1 directly descends to pick up the bolt, and the single-sided locking assembly can be carried out without manual adjustment of the tooling throughout the process.

[0035] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A tightening device, comprising: The frame (11) is characterized in that a first mounting plate (13) is movably provided on the frame (11), and a vertical moving component (1) is provided on the frame (11) for driving the first mounting plate (13) to move along the height direction of the frame (11); A second mounting plate (22) is movably mounted on the first mounting plate (13), and a horizontal moving component (2) is provided on the first mounting plate (13) for driving the second mounting plate (22) to move along the length direction of the frame (11); The second mounting plate (22) is provided with a tightening gun (32) connected to the mounting base (31). The output end of the tightening gun (32) is connected to a bolt sleeve (34). The bolt sleeve (34) is provided with a magnetic attracting element for attracting bolts. A rotary cylinder (41) and a bearing seat (42) are installed at the bottom of the frame (11). The output end of the rotary cylinder (41) is connected to a rotating shaft (43). The rotating shaft (43) is rotatably mounted on the bearing seat (42). A sleeve bracket (44) is connected to the rotating shaft (43). A nut sleeve (45) is connected to the sleeve bracket (44). The nut sleeve (45) is coaxially arranged with the bolt sleeve (34), and the nut sleeve (45) is provided with a magnetic attraction element for attracting nuts.

2. The tightening device according to claim 1, characterized in that, The vertical moving component (1) includes a first guide rail (12) and a first cylinder (14). The first guide rail (12) and the first cylinder (14) are both mounted on the frame (11). The first mounting plate (13) is connected to the slider of the first guide rail (12), and the output end of the first cylinder (14) is connected to the first mounting plate (13).

3. A tightening device according to claim 1, characterized in that, The horizontal moving component (2) includes a second guide rail (21) and a second cylinder (23). The second guide rail (21) and the second cylinder (23) are both mounted on the first mounting plate (13). The second mounting plate (22) is connected to the slider of the second guide rail (21). The output end of the second cylinder (23) is connected to the second mounting plate (22).

4. A tightening device according to claim 1, characterized in that, The tightening gun (32) is a right-angle tightening gun (32). The end of the tightening gun (32) is connected to an offset head (33). The offset head (33) has a built-in spring guide structure, which is used to provide clamping force to the bolt during the tightening process and compensate for position deviation.

5. A tightening device according to claim 1, characterized in that, The vertical moving component (1) has buffers and limiters on both sides of its travel to limit the range of movement of the first mounting plate (13) and reduce impact.

6. A tightening device according to claim 1, characterized in that, The rotating shaft (43) passes through the bearing seat (42) and the rotary cylinder (41) drives the rotating shaft (43) to rotate 180° along the bearing seat (42), so that the nut sleeve (45) switches between the downward material picking state and the upward locking state.

7. A tightening device according to claim 1, characterized in that, The second mounting plate (22) is provided with a vision sensor. The acquisition end of the vision sensor faces downwards from the bolt sleeve (34) and is used to identify the position of the connection hole of the workpiece to be assembled and to provide feedback to adjust the movement displacement of the vertical moving component (1) and the horizontal moving component (2).

8. A tightening method for the tightening device as described in any one of claims 1-7, characterized in that, include: The single-sided locking method includes the following steps in sequence: S1. The vertical moving component (1) is in the upper limit position, the horizontal moving component (2) is in the alignment position, and the nut sleeve (45) is facing upward; S2. The vertical moving component (1) drives the bolt sleeve (34) to descend to the standard parts tray, and then rises back after the bolt and flat washer are attracted by the magnetic component; S3. Align the bolt axis with the connecting hole axis, the vertical moving component (1) drives the bolt sleeve (34) to descend, and the tightening gun (32) rotates at low speed to guide the bolt through the through hole; S4. Tightening gun (32) tightens the bolt at the set speed, and collects the torque value and torsion angle value in real time. It stops when the torque reaches the preset threshold and the angle is within the allowable range. S5. The vertical moving component (1) drives the tightening gun component to rise, and the bolt sleeve (34) separates from the bolt.

9. The tightening method according to claim 8, characterized in that, Also includes: The double-sided locking method includes the following steps in sequence: S1. The rotary cylinder (41) drives the nut sleeve (45) to flip downwards, and the vertical moving component (1) drives the nut sleeve (45) to descend to the material tray, adsorb the nut and flat washer, and then rise and flip upwards. S2. The horizontal moving component (2) moves the tightening gun component to the clearance position, and resets after the bolt is picked up, so that the bolt sleeve (34) and the nut sleeve (45) are coaxially aligned. S3. Align the axis of the nut sleeve (45) with the connecting hole, and use the vertical moving component (1) to drive the bolt sleeve (34) to descend, so that the bolt passes through the through hole and fits against the nut; S4. Tighten the gun (32) by rotating it and tightening it. Monitor the torque and angle in real time and stop when the preset conditions are met.

10. The tightening method according to claim 9, characterized in that, During the tightening process, the spring-guided structure of the offset head (33) of the tightening gun (32) provides a clamping force of 5-8N to the bolt to compensate for positional deviations during assembly.

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