A rounding machine and a control method thereof

Abstract

The application discloses a rounding machine and a control method thereof, and belongs to the technical field of rounding machines. The rounding machine comprises a machine table, the top of the machine table is provided with a multi-roller conveying assembly, the inside of the multi-roller conveying assembly is provided with a square tube, one side of the top of the machine table is provided with a detection assembly, the multi-roller conveying assembly comprises a second driving roller, a third driving roller and an arc starting roller, the bending radius of the square tube is changed through the position change of the arc starting roller, the detection assembly comprises a rotating table, the bottom of the rotating table is provided with an angle sensor, the inside of the rotating table is slidably connected with a sliding rod, the inside of the rotating table is provided with a displacement sensor, the end of the sliding rod is provided with a box body, the inside of the box body is provided with a cross rod, the inside of the cross rod is provided with two limiting blocks, and the side of each limiting block is slidably connected with a sliding rail. The application directly calculates the bending radius based on the geometric definition of the arc, and eliminates the systematic error caused by the eccentricity of the installation of the detection mechanism in principle.

Description

Technical Field

[0001] This invention relates to the field of rolling machine technology, and in particular to a rolling machine and its control method. Background Technology

[0002] Roll forming machines are core processing equipment for bending and forming metal profiles. They are widely used in fields such as building steel structures, pipeline engineering, hardware lighting, and automotive parts, and are used to continuously roll and bend square tubes, round tubes, and other profiles into arc components with a set curvature. As the manufacturing industry upgrades towards higher precision and consistency, the curvature accuracy of profile bending directly determines the assembly quality and performance of the finished product, and the industry has placed higher demands on the forming control precision of roll forming machines.

[0003] Traditional rounding machines mostly employ an open-loop control mode, relying on manual experience to adjust the radial displacement of the initiating roller and pre-setting the roller position to complete the bending process. This type of equipment cannot perform online detection of the actual curvature of the bent profile, lacks real-time data feedback during processing, and is affected by multiple factors such as the springback characteristics of the metal profile, long-term roller wear, feed speed fluctuations, and profile wall thickness deviations. The actual bending curvature often deviates significantly from the target design value, requiring manual measurement and repeated adjustments after machine shutdown. This results in low production efficiency and poor consistency of finished products during batch processing, making it difficult to meet the demands of high-precision production.

[0004] In summary, existing rolling machines generally suffer from technical problems such as the inability to accurately detect the curvature after bending online, the detection accuracy being easily affected by structural and surface factors, the lack of a closed-loop feedback mechanism in forming control, and insufficient curvature control accuracy. These problems restrict the improvement of profile rolling forming quality and the optimization of production efficiency. Summary of the Invention

[0005] The purpose of this invention is to solve the problem that existing rolling machines mostly adopt open-loop control mode, which cannot achieve high-precision online detection and closed-loop feedback control of the curvature of the profile after bending, and the forming accuracy and production efficiency are difficult to meet the requirements of high-precision processing. Therefore, a rolling machine and its control method are proposed.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A rolling machine includes a machine base, a multi-roller conveying assembly is provided on the top of the machine base, a square tube is provided inside the multi-roller conveying assembly, and a detection assembly is provided on one side of the top of the machine base; The multi-roller conveying assembly includes a second drive roller, a third drive roller, and an arc-starting roller. The curvature of the square tube is changed by changing the position of the arc-starting roller. The detection assembly includes a turntable, an angle sensor at the bottom of the turntable, a sliding rod slidably connected inside the turntable, a displacement sensor inside the turntable, a housing at the end of the sliding rod, a crossbar inside the housing, two limiting blocks inside the crossbar, a slide rail slidably connected to one side of each limiting block, a second roller and a third roller respectively on the other side of the two limiting blocks, a movable box slidably connected to one side of the housing, a scraper inside the movable box, and a distance sensor at the bottom of the crossbar.

[0007] In some embodiments, the second drive roller, the third drive roller, and the arc-starting roller are rotatably connected to the top of the machine platform, the bottom of the turntable is rotatably connected to the machine platform, the two limiting blocks are symmetrically arranged with the center line of the crossbar as the axis of symmetry, the two limiting blocks are slidably connected to the crossbar, and the two slide rails are located on the inner sidewall of the box.

[0008] In some embodiments, the multi-roller conveying assembly further includes a plurality of first drive rollers arranged in a four-corner configuration. The bottom of the first drive rollers is rotatably connected to the machine base. A material receiving proximity switch is provided on one side of the top of the machine base. An adjustment frame is provided in the middle of the top of the machine base. An encoder is connected to the end of the adjustment frame. An arc-starting proximity switch is provided on the side of the encoder.

[0009] In some embodiments, the bottom of the arc-starting roller is rotatably connected to a slide table, the slide table is slidably connected to the machine base, a movable proximity switch is provided on the side of the slide table, the movable proximity switch is slidably connected to the top of the machine base, a first coil spring is fixedly connected to the bottom of the turntable, the other end of the first coil spring is fixedly connected to the top of the machine base, a first roller is provided at the end of the slide rod, the first roller can abut against the top of the square tube, a first spring is fixedly connected to the top of the turntable, and the other side of the first spring is fixedly connected to the top of the slide rod.

[0010] In some embodiments, a first connecting rod is rotatably connected to the bottom of the turntable, a second connecting rod is rotatably connected to the other end of the first connecting rod, a cylindrical rod is fixedly connected to the other end of the second connecting rod, the top of the cylindrical rod is fixedly connected to the housing, and the cylindrical rod passes through the end of the slide rod.

[0011] In some embodiments, an electric push rod is fixedly connected inside the box body. The bottom of the electric push rod is rotatably connected to a crossbar. A second coil spring is fixedly connected to the side of the crossbar away from the electric push rod. The middle part of the second coil spring is fixedly connected to the bottom hinge shaft of the electric push rod. A bent rod is fixedly connected to the telescopic end of the electric push rod. The bent rod passes through the side wall of the box body and is fixedly connected to the side wall of the movable box.

[0012] In some embodiments, a slider is slidably connected inside the movable box, a second spring is provided on the top of the slider, the top of the second spring is fixedly connected to the side wall of the movable box, a frame is slidably connected to the protruding part of the slider, the frame is slidably connected to the inner side wall of the movable box, and the protruding part of the slider is fixedly connected to a scraper.

[0013] In some embodiments, a sleeve rod is fixedly connected to the bottom of the frame, a vertical rod is slidably connected to the end of the sleeve rod, the vertical rod is slidably connected to the side wall of the box, a pull rod is fixedly connected to the end of the vertical rod, a control rod is fixedly connected to the end of the pull rod, a rotating block is sleeved on the outside of the control rod, and a swing rod is rotatably connected to one side of the rotating block.

[0014] In some embodiments, a telescopic rod is rotatably connected to the middle of the swing rod, and the telescopic rod is fixedly connected to the inner wall of the box. A first protrusion and a second protrusion are provided on the side of the swing rod near the telescopic rod. The first protrusion and the second protrusion are located at both ends of the swing rod. The first protrusion and the second protrusion cooperate with the crossbar. A toothed ring is sleeved on the outside of the hinge shaft of the crossbar and the electric push rod. An electromagnetic pin is provided on the outside of the toothed ring. The electromagnetic pin is fixedly connected to the electric push rod.

[0015] A control method for a rolling mill includes the following steps: S1: The square tube is conveyed to the forming station along the feeding direction by the multi-roller conveyor assembly, and the slide table is driven to move to adjust the initial position of the arc-starting roller and set the target bending radius R. S2: According to the formula The target radial movement of the arc-initiating roller is calculated, and the arc-initiating roller is controlled to move to the corresponding position to complete the pre-control of the bending arc of the square tube. Where A is the roller movement distance, B is the distance between the arc-initiating roller and the third drive roller, r is the roller radius, and D is the tube wall thickness of the square tube. S3: According to the formula The actual bending radius R' is calculated, where L is the moving distance of the slide bar, e is the lateral distance from the center of the second drive roller to the center of the turntable, h is the longitudinal distance between the center of the turntable and the upper edge of the square tube, and β is the rotation angle of the turntable. S4: Compare the actual bending radius R' with the target bending radius R. If there is a deviation, output a correction signal to the slide drive unit to adjust the radial position of the arc-starting roller, thereby achieving closed-loop feedback control of the bending arc.

[0016] Compared with the prior art, the present invention provides a rolling machine and its control method, which has the following beneficial effects.

[0017] 1. This invention utilizes a single-point arc-following detection structure composed of a turntable, a slide bar, an angle sensor, and a displacement sensor. This structure can collect the angle and displacement parameters of the profile bending in real time and calculate the actual bending radius. It forms a closed-loop feedback logic with the arc-starting roller drive mechanism, automatically compensating for arc deviations caused by factors such as metal profile springback, long-term roller wear, and profile wall thickness fluctuations. This replaces the traditional open-loop manual adjustment mode, effectively reducing forming errors and improving the arc accuracy of finished products and the dimensional consistency of batch processing.

[0018] 2. This invention uses the geometric calculation principle of fixing the chord length with dual rollers and real-time detection of chord height to directly calculate the bending radius based on the geometric definition of a circular arc, thus eliminating the installation eccentricity system error present in single-point deflection detection. The dual-point synchronous sampling can more completely characterize the actual bending shape of the profile, avoiding the one-sidedness of single-point sampling data, and the detection data is more rigorous and accurate.

[0019] 3. This invention, through the cooperation of the sliding rod and connecting rod, drives the box to rotate synchronously with the curvature of the profile, so that the contact surface of the double rollers automatically matches the tangential direction of the arc; in conjunction with the adjustable roller spacing structure driven by the electric push rod, the spacing can be enlarged for large bending radius conditions to improve detection resolution, and the spacing can be reduced for small bending radius conditions to ensure effective contact. The optimal detection accuracy is obtained through spacing matching, avoiding the accuracy degradation of fixed spacing under extreme curvature, and widening the range of curvature and pipe diameter adaptability of the equipment.

[0020] 4. In this invention, the pre-positioned elastic scraper structure removes impurities such as oxide scale and metal shavings from the pipe wall before the detection roller, preventing impurities from lifting the roller and causing jumps in detection data. Combined with the elastic torsional support of the crossbar by the second coil spring, it can buffer the instantaneous impact caused by small undulations in the pipe wall, continuously maintain the roller contact pressure and the stability of the detection benchmark, and effectively improve the continuity and stability of the detection data.

[0021] 5. This invention utilizes a purely mechanical linkage mechanism involving a sleeve rod, vertical rod, and swing rod triggered by scraper retraction. When encountering hard protrusions such as weld points or zinc nodules, it automatically switches to a single roller support mode, enabling the second and third rollers to alternately lift and avoid obstacles. This prevents both rollers from being simultaneously subjected to rigid impacts, thus avoiding wheel surface damage and equipment jamming. Obstacle crossing protection can be achieved without additional detection and drive components, effectively extending the service life of the detection components and improving the reliability of equipment operation.

[0022] 6. This invention allows for the synchronous adjustment of the roller detection spacing and the relative position of the scraper by an electric push rod. It can adapt to the processing of profiles with different pipe diameters and curvatures without replacing the detection components. At the same time, it can complete the calibration and compensation of the detection benchmark, reducing the cost of equipment replacement and the difficulty of maintenance.

[0023] Other advantages, objectives and features of the invention will be set forth in part in the description which follows; and in part will be apparent to those skilled in the art upon examination of the following description; or may be learned from practice of the invention. Attached Figure Description

[0024] Figure 1 This is a three-dimensional schematic diagram of the overall structure of the present invention.

[0025] Figure 2 This is a top view of the overall structure of the present invention.

[0026] Figure 3 This is a schematic diagram of the first coil spring and slide bar cooperation structure of the present invention.

[0027] Figure 4 This is a schematic diagram corresponding to the R calculation formula in this invention.

[0028] Figure 5 In this invention Schematic diagram corresponding to the calculation formula.

[0029] Figure 6 This is a schematic diagram of the sliding rod and the box body of the present invention.

[0030] Figure 7 This is a schematic diagram of the first connecting rod and the housing structure of the present invention.

[0031] Figure 8 This is a schematic diagram of the cross-sectional structure of the box body of the present invention.

[0032] Figure 9 This is a schematic diagram of the structure of the bent rod and the movable box of the present invention.

[0033] Figure 10 This is a schematic diagram of the disassembled and assembled structure of the scraper and vertical rod of the present invention.

[0034] Figure 11 This is a schematic diagram of the cooperation structure between the electric push rod and the crossbar of the present invention.

[0035] Figure 12 This is a schematic diagram of the structure of the vertical rod and the rotating block of the present invention.

[0036] Figure 13 This is a schematic diagram of the cooperation structure between the telescopic rod and the swing rod of the present invention.

[0037] Figure 14 This is a schematic diagram of the mating structure of the gear ring and electromagnetic pin of the present invention.

[0038] Figure 15 This is a schematic diagram of the second coil spring and crossbar cooperation structure of the present invention.

[0039] Figure 16In this invention Schematic diagram corresponding to the calculation formula.

[0040] In the picture: 1. First drive roller; 2. Machine base; 3. Square tube; 4. Encoder; 5. Arc initiation proximity switch; 6. Incoming material detection proximity switch; 7. Adjustment frame; 8. Second drive roller; 9. Third drive roller; 10. Arc initiation roller; 11. Slide table; 12. Motion proximity switch; 13. First coil spring; 14. Turntable; 15. Slide rod; 16. First spring; 17. First roller; 18. First connecting rod; 19. Second connecting rod; 20. Box body; 21. Electric push rod; 22. 23. Horizontal bar; 24. Slide rail; 25. Second roller; 26. Bent bar; 27. Cylindrical bar; 28. Scraper; 29. ​​Frame; 30. Slider; 31. Second spring; 32. Sleeve rod; 33. Vertical bar; 34. Limiting block; 35. Pull rod; 36. Control rod; 37. Rotating block; 38. Swing rod; 39. First protruding rod; 40. Second protruding rod; 41. Telescopic rod; 42. Gear ring; 43. Electromagnetic pin; 44. Second coil spring; 45. Third roller; 46. Moving box. Detailed Implementation

[0041] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0042] Example 1: Reference Figures 1-3 A rolling machine includes a machine base 2, a multi-roller conveying assembly on the top of the machine base 2, a square tube 3 inside the multi-roller conveying assembly, and a detection assembly on one side of the top of the machine base 2 for online acquisition of the actual curvature parameters of the square tube 3 after bending.

[0043] The multi-roller conveyor assembly includes a second drive roller 8, a third drive roller 9, and an arc-starting roller 10. The bending curvature of the square tube 3 is changed by changing the position of the arc-starting roller 10. The multi-roller conveyor assembly also includes multiple first drive rollers 1, which are arranged at four corners. The multiple first drive rollers 1 are arranged in two rows, one above the other, with the four corners corresponding to each other. The upper and lower rows of first drive rollers 1 form a feeding channel that is adapted to the cross-section of the square tube 3. Each first drive roller 1 is an active roller, and its roller shaft is connected to the drive motor. The bottom of the first drive roller 1 is rotatably connected to the machine base 2. The second drive roller 8, the third drive roller 9, and the arc-starting roller 10 are rotatably connected to the top of the machine base 2. The second drive roller 8 and the third drive roller 9 are arranged sequentially and at intervals along the feeding direction at the discharge end of the multi-roller conveyor assembly to stably support the square tube 3 during the bending process and form a forming reference support surface.

[0044] The detection assembly includes a turntable 14, with an angle sensor at the bottom of the turntable 14. The angle sensor can identify the rotation angle of the turntable 14. A slide rod 15 is slidably connected inside the turntable 14. A displacement sensor is installed inside the turntable 14, which can identify the extension distance of the slide rod 15 relative to the center of the turntable 14 in real time, thereby obtaining the distance from the center of the turntable 14 to the end of the slide rod 15. The bottom of the turntable 14 is rotatably connected to the machine base 2.

[0045] A material receiving proximity switch 6 is installed on one side of the top of the machine base 2. Located at the feeding end, the material receiving proximity switch 6 identifies the feeding status of the square tube 3 and simultaneously triggers the arc-starting action and arc detection program, enabling automatic start and stop of processing and inspection. An adjustment frame 7 is located in the middle of the top of the machine base 2. An encoder 4 is connected to the end of the adjustment frame 7. An arc-starting proximity switch 5 is located on the side of the encoder 4, corresponding to the initial zero position of the arc-starting roller 10. This switch is used to calibrate the reference origin for arc control, compensating for zero-point drift caused by equipment installation gaps and mechanical wear. The encoder 4 is linked to the drive roller shaft to record the feed length of the square tube 3 in real time, matching it with the real-time radius data of the arc detection component to form arc distribution data along the length of the entire profile, achieving continuous online monitoring throughout the entire processing process.

[0046] A slide table 11 is rotatably connected to the bottom of the arc-starting roller 10. The slide table 11 is slidably connected to the machine base 2. A movable proximity switch 12 is provided on the side of the slide table 11. The movable proximity switch 12 is slidably connected to the top of the machine base 2. The movable proximity switch 12 corresponds to the travel of the slide table 11 and is used for limit protection of the extreme position of the arc-starting roller 10 to ensure equipment safety during the adjustment process. A first coil spring 13 is fixedly connected to the bottom of the turntable 14. The other end of the first coil spring 13 is fixedly connected to the top of the machine base 2. The first coil spring 13 can provide a force for the turntable 14 to rotate towards the square tube 3, thereby enabling... To ensure that the end of the slide rod 15 is always in close contact with the side wall of the square tube 3, the end of the slide rod 15 is provided with a first roller 17, which can abut against the top of the square tube 3, so that the first roller 17 rolls against the outer side wall of the square tube 3. A first spring 16 is fixedly connected to the top of the turntable 14, and the other side of the first spring 16 is fixedly connected to the top of the slide rod 15. The first spring 16 can further apply a force close to the square tube 3 to the slide rod 15. Through the above components, it can be ensured that when the curvature of the square tube 3 changes, the extension and retraction of the slide rod 15 and the rotation angle of the turntable 14 change accordingly.

[0047] Example 2: Reference Figures 4-5 A control method for a rolling mill includes the following steps: S1: The square tube 3 is conveyed to the forming station along the feeding direction by the multi-roller conveyor assembly, and the slide table 11 is driven to move to adjust the initial position of the arc-starting roller 10 and set the target bending radius R. S2: According to the formula The target radial movement of the arc-initiating roller 10 is calculated, and the roller 10 is controlled to move to the corresponding position to complete the pre-control of the bending arc of the square tube 3. Here, A is the roller movement distance, B is the distance between the arc-initiating roller 10 and the third drive roller 9, r is the roller radius, and D is the wall thickness of the square tube 3. The geometric diagram for this formula is referenced. Figure 4 ; S3: According to the formula The actual bending radius R' is calculated, where L is the moving distance of the slide bar 15, e is the lateral distance from the center of the second drive roller 8 to the center of the turntable 14, h is the longitudinal distance between the center of the turntable 14 and the upper edge of the square tube 3, and β is the rotation angle of the turntable 14. The geometric diagram for this formula is referenced. Figure 5 ; S4: Compare the actual bending radius R' with the target bending radius R. If there is a deviation, output a correction signal to the slide table 11 drive unit to adjust the radial position of the arc-starting roller 10 and realize closed-loop feedback control of the bending arc.

[0048] It should be noted that: the above parameters are all calculated using the rotation center of turntable 14 as the origin of the geometric coordinate system; the moving distance L of slide bar 15 is obtained by converting the reading of displacement sensor inside turntable 14 after zero-point calibration; the rotation angle β of turntable 14 is obtained by corresponding to the output value of angle sensor at the bottom of turntable 14 after zero-position calibration; e and h are the equipment reference installation dimensions, which can be calibrated and corrected according to the actual assembly accuracy during on-site use.

[0049] During operation, the square tube 3 is first clamped by the multi-roller conveying assembly and smoothly conveyed to the forming station at a low speed of 0-50 mm / s along the feeding direction. When the tube head is fed to a position exceeding 1.5 times the tube diameter D of the center of the arc-starting roller 10, the feeding speed is reduced to a low-speed arc-starting condition of 0-5 mm / s. The control system drives the slide table 11 to move to adjust the initial position of the arc-starting roller 10 and presets the target bending radius R of the profile. Subsequently, the control system combines the forming geometric parameters such as the roller moving distance, the roller center distance, the roller radius, and the tube wall thickness of the square tube 3 to calculate the target radial movement amount corresponding to the arc-starting roller 10. The pre-arc displacement is executed at 1.05 times the target movement amount, and the slide table 11 is precisely controlled to drive the arc-starting roller 10 to move to the target position, and the corresponding degree of lateral extrusion force is applied to the square tube 3 to complete the pre-controlled forming of the bending arc.

[0050] During the continuous roll bending of square tube 3, the feed speed is increased to 70% of the rated value to enter the stable forming stage. The arc detection component maintains a tight fit between the detection end and the outer wall of square tube 3 through a double elastic follow-up structure. The turntable 14 deflects synchronously with the tangential direction of square tube 3, and the slide rod 15 extends and retracts synchronously with the radial height of the tube wall. The control system combines parameters such as the rotation angle of the turntable 14, the moving distance of the slide rod 15, and the equipment reference installation dimensions to calculate the actual bending radius R' of square tube 3 at its current position in real time. The control system compares the real-time collected actual bending radius R' with the preset target bending radius R. When the monitored value exceeds 0.9~1.0, the system will detect the bending radius R'. When the radius of the target radius R is within a certain range, the corresponding correction signal is immediately output to the drive unit of the slide table 11 to dynamically adjust the radial feed position of the arc-starting roller 10 and automatically compensate for the arc error caused by factors such as metal profile springback, long-term roller wear, and profile wall thickness fluctuation. When the tail of the tube leaves the position of the incoming material detection proximity switch 6, the feed speed is reduced to 60% of the rated value to enter the arc-ending stage. After the tail of the tube completely leaves the forming station, the equipment runs for a delay of 3 times the distance between the first row of feed rollers and the arc-starting roller before all actions are reset, thereby realizing the full closed-loop feedback control of the entire process of square tube 3 rolling bend, and continuously ensuring the accuracy of the forming arc and the consistency of batch processing.

[0051] Example 3: Reference Figures 6-16 Based on Examples 1 and 2, it was found that the single-point curvature detection structure still has certain application limitations. Single-point detection relies on a single detection point to collect the radial offset signal of the profile, which is easily affected by factors such as local protrusions on the profile surface. The detection data fluctuates greatly. At the same time, the sampling results of a single point are difficult to fully represent the actual bending shape of the profile. There are problems such as one-sided data representation and insufficient anti-interference ability, which ultimately limits the further improvement of the overall detection accuracy.

[0052] The end of the slide bar 15 is provided with a box 20. Inside the box 20 is a crossbar 22. Inside the crossbar 22 are two limiting blocks 33. The limiting blocks 33 can only move along the direction of the crossbar 22 inside the crossbar 22. One side of each limiting block 33 is slidably connected to a slide rail 23. The middle part of the slide rail 23 is a diagonal segment. The distance between the top of the diagonal segment of the two slide rails 23 is greater than the distance between the bottom. The top and bottom of the slide rail 23 are both straight segments. The other side of the two limiting blocks 33 is provided with a second roller 24 and a third roller 44, respectively. The second roller 24 and the third roller 44 are normally at the same height, which can realize dual-point curvature detection of the square tube 3. A movable box 45 is slidably connected to one side of the box 20. The movable box 45 can move up and down along the side of the box 20. Inside the movable box 45 is a scraper 27. The bottom of the scraper 27 abuts against the top side of the square tube 3. The positional relationship of the second roller 24 and the third roller 44 can be adjusted according to the crossbar. The height and tilt of the crossbar 22 change accordingly. Moving the crossbar 22 up or down can change the distance between the second roller 24 and the third roller 44, which is used to adjust and adapt to the detection of arcs with different bending radii. For large bending radius (small curvature) conditions, the roller spacing can be appropriately increased to amplify the deflection angle and displacement corresponding to the same curvature change, improve detection resolution, and reduce relative measurement error. For small bending radius (large curvature) conditions, the roller spacing can be reduced to ensure that both rollers fall within the same effective arc segment, avoiding problems such as roller contact failure and detection point deviation from the arc surface normal caused by excessive curvature. By matching the spacing, the optimal detection accuracy can be obtained for different processing conditions, avoiding the accuracy degradation of fixed spacing under extreme curvature. A distance sensor is provided at the bottom of the crossbar 22. The distance sensor at the bottom of the crossbar 22 can identify the distance of the bent square tube 3. The distance sensor corresponds to the lowest point of the arc between the two rollers.

[0053] Two limiting blocks 33 are symmetrically arranged about the center line of the crossbar 22. The two limiting blocks 33 are slidably connected to the crossbar 22 and slide back and forth inside the crossbar 22. Two slide rails 23 are located on the inner side wall of the box 20. The slide rails 23 can adjust the distance between the second roller 24 and the third roller 44. Since the top and bottom of the slide rails 23 are straight sections, when the crossbar 22 rotates, it can drive the two limiting blocks 33 to move. Both limiting blocks 33 enter the straight section of the slide rails 23, which can speed up the movement. When the scraper 27 encounters a large protrusion or weld point, the second roller 24 can be quickly lifted and the third roller 44 can be quickly extended to provide support. Then the second roller 24 falls and then drives the third roller 44 to be lifted, thereby realizing the sequential lifting of the second roller 24 and the third roller 44, preventing the weld point or protrusion from impacting the second roller 24 and the third roller 44 and damaging the surface of the rollers.

[0054] A first connecting rod 18 is rotatably connected to the bottom of the turntable 14. A second connecting rod 19 is rotatably connected to the other end of the first connecting rod 18. A cylindrical rod 26 is fixedly connected to the other end of the second connecting rod 19. The top of the cylindrical rod 26 is fixedly connected to the box body 20. The cylindrical rod 26 passes through the end of the sliding rod 15. When the curvature of the square tube 3 decreases (curvature increases), the sliding rod 15 moves towards the turntable 14. When the curvature of the square tube 3 increases (curvature decreases), the sliding rod 15 moves away from the turntable 14. When the curvature decreases (curvature increases), the sliding rod 15 first moves towards the turntable 14. During this process, because the distance between the turntable 14 and the box body 20 decreases, the first connecting rod 18 and the second connecting rod 19 will rotate. Figure 6 In the indicated state, the first connecting rod 18 rotates counterclockwise, and the second connecting rod 19 rotates clockwise. The second connecting rod 19 then drives the cylindrical rod 26 to rotate, thereby achieving clockwise rotation of the box body 20. Consequently, the angle between the center lines of the second roller 24 and the third roller 44 mounted on the box body 20 deflects synchronously with the box body 20, allowing the contact surfaces of the two rollers to adaptively match the tangent direction of the arc after the curvature increases. This ensures that the wheel surfaces of both rollers simultaneously and completely contact the arc-shaped outer wall of the square tube 3, avoiding problems such as roller edge contact, contact gaps, or jamming caused by changes in curvature. Conversely, when the bending radius of the square tube 3 increases and the curvature decreases, the tube wall pushes the sliding rod 15 outward, causing it to extend. Through the reverse transmission of the linkage mechanism, this drives the box body 20 to deflect counterclockwise, similarly ensuring stable contact between the two rollers and the gently curving surface.

[0055] An electric push rod 21 is fixedly connected inside the housing 20. The bottom of the electric push rod 21 is rotatably connected to the crossbar 22. A second coil spring 43 is fixedly connected to the side of the crossbar 22 away from the electric push rod 21. The middle part of the second coil spring 43 is fixedly connected to the bottom hinge shaft of the electric push rod 21. The second coil spring 43 adopts a high elastic coefficient specification, and its torsional stiffness is greater than the equivalent stiffness of the roller under excited vibration under the detection condition. Under normal detection conditions, the second coil spring 43 maintains the angle stability of the crossbar 22 relative to the output end of the electric push rod 21 by its own elastic torque, so that the detection roller at the end of the crossbar 22 maintains a stable initial posture and preset clamping force, ensuring that the detection reference of the double roller does not drift, and ensuring the stability and consistency of the curvature detection data. When the profile surface shows When defects such as weld points, zinc nodules, and local unevenness are detected, the instantaneous impact on the detection roller can be mitigated by the slight swing of the crossbar 22 around the hinge axis, compressing the second coil spring 43 to achieve elastic displacement. This avoids rigid jamming between the roller and the profile, which would exacerbate wear, and also maintains the contact pressure between the roller and the tube wall, preventing detection interruption or data jumps. The telescopic end of the electric push rod 21 is fixedly connected to a bent rod 25, which passes through the side wall of the box 20 and is fixedly connected to the side wall of the movable box 45. When the electric push rod 21 moves the crossbar 22, it can simultaneously move the movable box 45 through the bent rod 25, so that the scraper 27 can be aligned with the bottom of the second roller 24 and the third roller 44, ensuring that the scraper 27 can always protect the second roller 24.

[0056] A slider 29 is slidably connected inside the movable box 45. A second spring 30 is provided on the top of the slider 29, and the top of the second spring 30 is fixedly connected to the side wall of the movable box 45. A frame 28 is slidably connected to the protruding part of the slider 29, and the frame 28 is slidably connected to the inner side wall of the movable box 45. The protruding part of the slider 29 is fixedly connected to the scraper 27. The elastic force of the second spring 30 pushes the slider 29 to slide down along the inner wall of the movable box 45, causing the scraper 27 to extend synchronously and press against the outer surface of the square tube 3 with stable pressure. As the square tube 3 is continuously fed along the feeding direction, the cutting edge of the scraper 27 continuously slides relative to the tube wall surface, scraping off and peeling off impurities such as oxide scale, dust, and metal shavings attached to the outer wall of the square tube 3, preventing impurities from entering between the contact surface between the detection roller and the tube wall, and eliminating impurity-induced damage. The problem of radial lifting of the detection roller and fluctuation of detection data caused by the padding provides a clean and stable surface reference for subsequent curvature detection. When the weld point, zinc nodule, local burr or protrusion defect on the surface of the square tube 3 passes the position of the scraper 27, the protrusion structure generates a reverse pushing force on the scraper 27. This force overcomes the elastic force of the second spring 30 and pushes the scraper 27, slider 29 and frame 28 to retract upward along the inner wall of the moving box 45. The second spring 30 is compressed. After the protrusion structure has completely passed, the second spring 30 releases its elastic potential energy and quickly pushes the slider 29 and scraper 27 to reset, so that the scraper 27 abuts against the tube wall again and restores the continuous cleaning state. When the scraper 27 is compressed, it will drive the slider 29 to move, thereby driving the frame 28 to move towards the box 20.

[0057] A sleeve rod 31 is fixedly connected to the bottom of the frame 28. A vertical rod 32 is slidably connected to the end of the sleeve rod 31. The vertical rod 32 is slidably connected to the side wall of the box 20. A pull rod 34 is fixedly connected to the end of the vertical rod 32. A control rod 35 is fixedly connected to the end of the pull rod 34. A rotating block 36 is sleeved on the outside of the control rod 35. A swing rod 37 is rotatably connected to one side of the rotating block 36. A telescopic rod 40 is rotatably connected to the middle of the swing rod 37. The telescopic rod 40 can drive the swing rod 37 to actively adjust its position. The electric push rod 21 rotates the crossbar 22. The telescopic rod 40 is fixedly connected to the inner wall of the box 20. The swing rod 37 has a first protrusion 38 and a second protrusion 39 on the side near the telescopic rod 40. The first protrusion 38 and the second protrusion 39 are located at both ends of the swing rod 37. The first protrusion 38 and the second protrusion 39 cooperate with the crossbar 22. When the scraper 27 is compressed, it will drive the frame 28 to move the sleeve rod 31 inward, and at the same time drive the slidably connected vertical rod 32 to move inward to the inside of the box 20. When the movable box 45 moves, it can still drive the vertical rod 32 to move inward and outward. The vertical rod 32 pulls the fixedly connected pull rod 34 to move. The pull rod 34 drives the fixedly connected control rod 35 to move. The control rod 35 can drive the rotating block 36 to move. The rotating block 36 can drive the bottom of the swing rod 37 to rotate, thereby changing the position of the first protrusion 38 and the second protrusion 39. When the rotating block 36 moves away from the box body 20, it can drive the swing rod 37 to rotate clockwise, so that the first protrusion 38 rotates to the top of the horizontal bar 22. When the electric push rod 21 retracts, it can drive the horizontal bar 22 to move upward as a whole. At this time, the first protrusion 38 abuts against the side of the horizontal bar 22 to form a limit, so that it cannot rotate upward, thereby realizing the counterclockwise rotation of the horizontal bar 22. The horizontal bar 22 will drive the two slidingly connected limit blocks 33 to move one side upward and the other side downward, so that it quickly enters the interior of the straight section, causing the second roller 24 to rise quickly and the third roller 44 to extend downward to form a single roller for support.

[0058] A gear ring 41 is sleeved on the outer side of the hinge shaft between the crossbar 22 and the electric push rod 21. An electromagnetic pin 42 is provided on the outer side of the gear ring 41. The electromagnetic pin 42 is fixedly connected to the electric push rod 21. The electromagnetic pin 42 can extend to constrain the gear ring 41 and fix the angle of the crossbar 22. When the second roller 24 is raised, the angle of the crossbar 22 can be locked first. When the second roller 24 passes the protrusion or weld point, the constraint on the gear ring 41 is released. Then, under the action of the second coil spring 43, the crossbar 22 can be reset. During the reset process, the scraper 27 will move quickly within the moving box 45 under the action of the second spring 30. The movement causes the frame 28 to move to the right, which in turn causes the swing rod 37 to rotate counterclockwise, rotating the second protruding rod 39 to the bottom side of the crossbar 22. Then, the electric push rod 21 extends and causes the crossbar 22 to move downward, causing the second roller 24 to extend downward and the third roller 44 to retract into the box 20, so that the third roller 44 passes over the protrusion of the square tube 3. The second roller 24 is in a single roller support state. The first protruding rod 38 and the second protruding rod 39 will quickly drive the crossbar 22 to rotate to an incline. Then, the angle of the crossbar 22 is fixed by the electromagnetic pin 42. After the electromagnetic pin 42 releases the constraint on the gear ring 41, the crossbar 22 automatically returns to its original position.

[0059] The formula for calculating the radius of the dual rollers is as follows: ,like Figure 16 As shown, a is the chord length AB, b is the chord height CD, the distance of AB can be calculated based on the extension length of the electric push rod 21 and the spacing of the slide rail 23, and the distance sensor at the bottom of the crossbar 22 obtains the distance of CD, thus completing the calculation of the arc.

[0060] It should be noted that: the chord length a is based on the center distance between the second roller 24 and the third roller 44, and can be calculated by combining the extension and retraction of the electric push rod 21 with the geometric parameters of the slide rail 23; the chord height b is based on the initial zero position of the crossbar 22, and is collected in real time by the distance sensor at the bottom of the crossbar 22; the zero point can be calibrated by a standard arc sample before use, and the reference value can be corrected according to the detection accuracy requirements during debugging.

[0061] In this invention, when the curvature of the square tube 3 changes, the slide rod 15 extends and retracts radially along the turntable 14. Through the linkage transmission pair formed by the first connecting rod 18, the second connecting rod 19 and the cylindrical rod 26, the box body 20 is driven to rotate synchronously around the axis of the cylindrical rod 26, so that the center line connecting the second roller 24 and the third roller 44 always matches the tangent direction of the current arc, ensuring that the wheel surfaces of the two rollers are completely in contact with the tube wall at the same time, and adapting to different bending radius detection conditions.

[0062] Based on the processing pipe diameter and target curvature, the electric push rod 21 drives the crossbar 22 to move radially up and down. The crossbar 22 drives the two limit blocks 33 to slide along the slide rail 23, correspondingly adjusting the center distance between the second roller 24 and the third roller 44: for small bending radius (large curvature) conditions, the roller distance is reduced to ensure that both rollers are within the same effective arc segment; for large bending radius (small curvature) conditions, the roller distance is increased to amplify the displacement corresponding to the curvature change and improve the detection resolution. At the same time, the electric push rod 21 drives the moving box 45 to move up and down along the side wall of the box body 20 through the bent rod 25, so that the scraper 27 is always aligned with the detection end face of the roller, maintaining the relative position of the pre-cleaning, ensuring that the scraper 27 contacts the pipe wall before the roller during the feeding of the square tube 3, and continuously cleaning and protecting the detection area.

[0063] Under normal testing conditions, the second spring 30 pushes the scraper 27 to press against the surface of the square tube 3 with stable pressure. As the square tube 3 continuously feeds, it scrapes away impurities such as oxide scale, dust, and metal shavings from the tube wall, preventing impurities from entering the roller contact surface and causing fluctuations in the test data. The second coil spring 43 maintains the angle stability of the crossbar 22 by relying on its own high elastic coefficient, ensuring that the detection benchmark of the dual rollers does not drift. Minor undulations in the tube wall can be buffered by the small swing of the crossbar 22 compressing the second coil spring 43. During this stage, the scraper 27 only extends and retracts slightly. Through the transmission of the sleeve rod 31, vertical rod 32, and pull rod 34, it only drives the swing rod 37 to deflect at a small angle. A safe threshold gap is maintained between the first protrusion 38, the second protrusion 39, and the crossbar 22, which will not trigger the switching of the roller support mode, ensuring the stability of the dual roller detection.

[0064] When large, hard protrusions such as weld points or zinc nodules appear on the surface of the square tube 3 that cannot be removed by the scraper 27, the scraper 27 is significantly lifted, causing the slider 29 and frame 28 to retract inward simultaneously. This pushes the vertical rod 32 along the inner side of the box 20 via the sleeve rod 31, and then drives the rotating block 36 to move via the pull rod 34 and control rod 35. This drives the swing rod 37 to rotate significantly clockwise around the telescopic rod 40, causing the first protruding rod 38 to rotate to the top side of the crossbar 22. At this time, the electric push rod 21 retracts, causing the crossbar 22 to move upward as a whole. The side of the crossbar 22 is limited and blocked by the first protruding rod 38, causing the crossbar 22 to deflect counterclockwise around the hinge axis. This causes the two limiting blocks 33 to slide quickly from the oblique section of the slide rail 23 into the straight section, realizing the rapid lifting and avoidance of the second roller 24 and the downward extension of the third roller 44. This switches to a single-wheel support state for the third roller 44, avoiding damage to the wheel surface or equipment jamming caused by the simultaneous impact of hard protrusions on both rollers.

[0065] When the protrusion reaches the position of the third roller 44, the electromagnetic pin 42 extends and engages with the gear ring 41, temporarily locking the deflection angle of the crossbar 22 to ensure the stability of the single-wheel support state. After the protrusion has completely passed, the electromagnetic pin 42 releases the constraint on the gear ring 41, and the second coil spring 43 drives the crossbar 22 to deflect in the opposite direction and reset. At the same time, the scraper 27 extends and resets quickly under the action of the second spring 30, driving the swing rod 37 to rotate counterclockwise and rotate the second protrusion 39 to the bottom side of the crossbar 22. The electric push rod 21 extends in coordination to drive the crossbar 22 to move down, so that the third roller 44 is raised to avoid the obstacle and the second roller 24 extends to support, completing the alternating obstacle crossing of the two rollers and finally restoring the normal detection state of the two rollers.

[0066] During the testing process, the center chord length 'a' of the double rollers can be calculated by the extension and retraction of the electric push rod 21 and the parameters of the slide rail 23. The distance sensor at the bottom of the crossbar 22 collects the chord height 'b' in real time. Based on the chord height calculation formula, the actual bending radius of the square tube 3 can be calculated in real time, thus completing high-precision online arc detection.

[0067] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0068] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

Claims

1. A rolling machine, comprising a machine base (2), characterized in that, The machine (2) is provided with a multi-roller conveyor assembly at the top, and a square tube (3) is provided inside the multi-roller conveyor assembly. A detection assembly is provided on one side of the top of the machine (2). The multi-roller conveying assembly includes a second drive roller (8), a third drive roller (9), and an arc-starting roller (10). The curvature of the square tube (3) is changed by changing the position of the arc-starting roller (10). The detection assembly includes a turntable (14), an angle sensor at the bottom of the turntable (14), a slide rod (15) slidably connected inside the turntable (14), a displacement sensor inside the turntable (14), a box (20) at the end of the slide rod (15), a crossbar (22) inside the box (20), two limiting blocks (33) inside the crossbar (22), a slide rail (23) slidably connected to one side of each limiting block (33), a second roller (24) and a third roller (44) respectively on the other side of the two limiting blocks (33), a movable box (45) slidably connected to one side of the box (20), a scraper (27) inside the movable box (45), and a distance sensor at the bottom of the crossbar (22).

2. A rolling machine according to claim 1, characterized in that, The second drive roller (8), the third drive roller (9) and the arc-starting roller (10) are rotatably connected to the top of the machine base (2), the bottom of the turntable (14) is rotatably connected to the machine base (2), the two limiting blocks (33) are symmetrically arranged with the center line of the crossbar (22) as the axis of symmetry, the two limiting blocks (33) are slidably connected to the crossbar (22), and the two slide rails (23) are located on the inner side wall of the box body (20).

3. A rolling machine according to claim 1, characterized in that, The multi-roller conveying assembly also includes multiple first drive rollers (1), which are arranged in a four-corner arrangement. The bottom of the first drive rollers (1) is rotatably connected to the machine base (2). A material detection proximity switch (6) is provided on one side of the top of the machine base (2). An adjustment frame (7) is provided in the middle of the top of the machine base (2). An encoder (4) is connected to the end of the adjustment frame (7). An arc-starting proximity switch (5) is provided on the side of the encoder (4).

4. A rolling machine according to claim 1, characterized in that, The bottom of the arc-starting roller (10) is rotatably connected to a slide table (11), which is slidably connected to the machine platform (2). A movable proximity switch (12) is provided on the side of the slide table (11), which is slidably connected to the top of the machine platform (2). A first coil spring (13) is fixedly connected to the bottom of the turntable (14), and the other end of the first coil spring (13) is fixedly connected to the top of the machine platform (2). A first roller (17) is provided at the end of the slide rod (15), and the first roller (17) can abut against the top of the square tube (3). A first spring (16) is fixedly connected to the top of the turntable (14), and the other side of the first spring (16) is fixedly connected to the top of the slide rod (15).

5. A rolling machine according to claim 1, characterized in that, The bottom of the turntable (14) is rotatably connected to a first connecting rod (18), the other end of the first connecting rod (18) is rotatably connected to a second connecting rod (19), the other end of the second connecting rod (19) is fixedly connected to a cylindrical rod (26), the top of the cylindrical rod (26) is fixedly connected to the box body (20), and the cylindrical rod (26) passes through the end of the slide rod (15).

6. A rolling machine according to claim 1, characterized in that, An electric push rod (21) is fixedly connected inside the box body (20). The bottom of the electric push rod (21) is rotatably connected to the crossbar (22). A second coil spring (43) is fixedly connected to the side of the crossbar (22) away from the electric push rod (21). The middle part of the second coil spring (43) is fixedly connected to the bottom hinge shaft of the electric push rod (21). A bent rod (25) is fixedly connected to the telescopic end of the electric push rod (21). The bent rod (25) passes through the side wall of the box body (20). The bent rod (25) is fixedly connected to the side wall of the movable box (45).

7. A rolling machine according to claim 1, characterized in that, The movable box (45) is slidably connected to a slider (29). A second spring (30) is provided on the top of the slider (29). The top of the second spring (30) is fixedly connected to the side wall of the movable box (45). A frame (28) is slidably connected to the protruding part of the slider (29). The frame (28) is slidably connected to the inner side wall of the movable box (45). The protruding part of the slider (29) is fixedly connected to a scraper (27).

8. A rolling machine according to claim 7, characterized in that, A sleeve rod (31) is fixedly connected to the bottom of the frame (28). A vertical rod (32) is slidably connected to the end of the sleeve rod (31). The vertical rod (32) is slidably connected to the side wall of the box (20). A pull rod (34) is fixedly connected to the end of the vertical rod (32). A control rod (35) is fixedly connected to the end of the pull rod (34). A rotating block (36) is sleeved on the outside of the control rod (35). A swing rod (37) is rotatably connected to one side of the rotating block (36).

9. A rolling machine according to claim 8, characterized in that, The swing rod (37) is rotatably connected to a telescopic rod (40) in the middle. The telescopic rod (40) is fixedly connected to the inner wall of the box (20). The swing rod (37) has a first protrusion (38) and a second protrusion (39) on the side near the telescopic rod (40). The first protrusion (38) and the second protrusion (39) are located at both ends of the swing rod (37). The first protrusion (38) and the second protrusion (39) cooperate with the crossbar (22). A toothed ring (41) is sleeved on the outside of the hinge shaft of the crossbar (22) and the electric push rod (21). An electromagnetic pin (42) is provided on the outside of the toothed ring (41). The electromagnetic pin (42) is fixedly connected to the electric push rod (21).

10. A control method for a rounding machine, applied to the rounding machine according to any one of claims 1 to 9, characterized in that, Includes the following steps: S1: The square tube (3) is conveyed to the forming station along the feeding direction by the multi-roller conveyor assembly, and the slide table (11) is driven to move to adjust the initial position of the arc-starting roller (10) and set the target bending radius R. S2: According to the formula The target radial movement of the arc-starting roller (10) is calculated, and the arc-starting roller (10) is controlled to move to the corresponding position to complete the pre-control of the bending arc of the square tube (3). A is the roller movement distance, B is the distance between the arc-starting roller (10) and the third drive roller (9), r is the roller radius, and D is the tube wall thickness of the square tube (3). S3: According to the formula The actual bending radius R' is calculated, where L is the moving distance of the slide bar (15), e is the lateral distance from the center of the second drive roller (8) to the center of the turntable (14), h is the longitudinal distance between the center of the turntable (14) and the upper edge of the square tube (3), and β is the rotation angle of the turntable (14). S4: Compare the actual bending radius R' with the target bending radius R. If there is a deviation, output a correction signal to the slide table (11) drive unit to adjust the radial position of the arc-starting roller (10) and realize closed-loop feedback control of the bending arc.

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