Device and method for detecting and self-adjusting the pitch of a steel tube

Abstract

This invention provides a device and method for detecting and self-adjusting the pitch marking of steel pipes. The device includes a steel pipe and a frame. A main control box and a painting control box are fixed to the side of the frame. The steel pipe is placed above the frame. Multiple conveying components are arranged between the steel pipe and the frame. A movable detection component and a painting component are located on one side above the frame. This invention provides a device for detecting and self-adjusting the pitch marking of steel pipes, enabling automatic detection and self-adjustment of the pitch marking on the conveyor line during the external anti-corrosion coating of steel pipes. It eliminates the need for manual operation, improves operator safety, increases automation, reduces adjustment time, and improves production efficiency. It also solves the problem of requiring manual positioning during the lateral polyethylene winding process on the outer surface of steel pipes.

Description

Technical Field

[0001] This invention relates to the field of steel pipe thread pitch measurement, and in particular to a device for detecting and self-adjusting steel pipe thread pitch markings. Background Technology

[0002] When using a lateral winding process for three-layer polyethylene anti-corrosion coating on steel pipes, the steel pipe advances spirally on the conveyor rollers. After adjusting the conveyor rollers to form a certain angle (i.e., helix angle) with the central axis of the steel pipe, the rotating conveyor rollers can push the steel pipe forward spirally according to the pitch. To ensure complete coating coverage on different steel pipes, for a fixed pitch but different pipe diameters, the conveyor rollers need to be adjusted to different angles, i.e., different helix angles. This adjustment involves adjusting the angle of the rotating drive roller at the bottom of the steel pipe.

[0003] During production, the drive roller wears down over time. If the preset angle value is calculated according to the standard, the pitch may not meet the production requirements after the corresponding steel pipe rotates one revolution. To solve this problem, most domestic methods for adjusting the pitch are as follows: First, the angle of the drive roller is manually adjusted to the preset angle value. Then, the conveyor line is turned on, and a person holds a piece of chalk close to the rotating steel pipe, leaving a chalk spiral. The distance of the spiral is measured manually and compared with the required pitch value. If the deviation does not meet the requirements, the machine is stopped, and the angle of the bottom drive roller is adjusted again. The process is then repeated.

[0004] Throughout the entire adjustment process, the pitch marking, distance detection, and drive roller angle adjustment on the conveyor line are all done manually. Specifically, workers manually mark and measure the pitch lines on the rotating steel pipe. Safety regulations prohibit workers from operating on rotating equipment and workpieces. This manual pitch marking method poses a significant safety risk and does not comply with national safety production requirements. Furthermore, the pitch adjustment and drive roller angle adjustment cannot be automatically performed in a closed loop, resulting in low automation, long adjustment times, and reduced work efficiency. Summary of the Invention

[0005] The main objective of this invention is to provide a device for detecting and self-adjusting the pitch marking of steel pipes, which solves the problem of manual positioning required during the lateral winding process of polyethylene on the outer surface of steel pipes.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a device for detecting and self-adjusting the pitch marking of steel pipes, including a steel pipe and a frame, a main control box and a paint spraying control box are fixed on the side of the frame, the steel pipe is placed on the top of the frame, multiple conveying components are provided between the steel pipe and the frame, and a movable detection component and a paint spraying component are provided on one side above one side of the frame.

[0007] In the preferred embodiment, the main control box is equipped with a network switch and a PLC.

[0008] In the preferred embodiment, the plurality of conveying components are symmetrically arranged at a certain angle on both sides of the bottom of the steel pipe.

[0009] In a preferred embodiment, the conveying assembly is provided with a speed reducer mounting plate, one side of which is fixed to the frame and the other side is fixed with a rotary speed reducer. A rotatable roller frame is provided above the rotary speed reducer, and a rotary motor is fixed to one side of the rotary speed reducer.

[0010] The roller frame has a rotatable roller in the middle, a conveyor reducer on one side of the roller frame, a connecting flange between the conveyor reducer and the roller frame, and a conveyor motor fixed on one side of the conveyor reducer.

[0011] In a preferred embodiment, the roller is made of wear-resistant rubber material, and the outer circumference of the roller is provided with anti-slip texture.

[0012] In a preferred embodiment, the frame is provided with a testing base and a painting base on the side near the main control box.

[0013] In a preferred embodiment, a second forward-moving bracket is fixed above the paint spraying base. A first motor is provided at one end of the second forward-moving bracket. A first lead screw is connected to the output shaft end of the first motor. A movable paint spraying bracket is provided on the first lead screw. A spray nozzle and a first rangefinder are provided on the top of the paint spraying bracket.

[0014] In a preferred embodiment, the detection base is provided with a first forward-moving bracket, one end of which is provided with a third motor. The output shaft of the third motor is connected to a second lead screw, and the second lead screw is provided with a movable lifting support plate. Below the lifting support plate is a second motor, and the output shaft of the second motor is connected to the third lead screw. The third lead screw is provided with a liftable detection bracket, and the detection bracket is provided with a second rangefinder and a camera.

[0015] The adjustment method of the above-mentioned steel pipe pitch marking detection and self-adjustment device includes:

[0016] S1. Set parameters on the touch screen, including steel pipe diameter, nozzle distance from steel pipe, camera height from ground, camera distance from steel pipe, process pitch distance, allowable deviation range, and preset angle value;

[0017] S2. After setting the distance between the nozzle and the steel pipe, the first motor drives the first rangefinder and the nozzle on the top of the paint spraying bracket to move closer to the outer wall of the steel pipe. When the first rangefinder reaches the set position, the first motor stops driving.

[0018] S2. After setting the steel pipe diameter and camera position parameters, the second motor drives the detection bracket to rise to a position that is flush with half the diameter of the steel pipe. The third motor drives the second rangefinder and camera on the lifting support plate to move closer to the outer wall of the steel pipe. When the second rangefinder reaches the set position, the third motor stops driving.

[0019] S3. After setting the deflection angle of the roller, the rotary motor controls the roller frame to deflect to the preset angle, and the roller abuts against the steel pipe at a certain angle.

[0020] S4. Spraying paint on the surface of the steel pipe: Start the conveyor motor to drive the rollers. Due to the deflection angle between the rollers and the steel pipe, the steel pipe above will move forward at a constant speed. The spray nozzle will start spraying paint and form a spiral paint line on the surface of the steel pipe.

[0021] S5. When the paint line enters the camera's field of view, the camera will transmit the image containing the paint line to the PC, extract the outlines of the two paint lines, and then use an algorithm to calculate the actual pitch distance value.

[0022] S6 and PC will compare the pitch data in the main control box with the preset process pitch distance and allowable deviation range in S. When the actual pitch exceeds the tolerance, the main control box will give an angle correction signal to the control unit to control the rotary motor.

[0023] S7. After correction, repeat steps S4 and S5 until the pitch measurement value falls within the process pitch distance range.

[0024] This invention provides a device for detecting and self-adjusting the pitch markings of steel pipes, which has the following beneficial effects:

[0025] 1. This invention provides a device for detecting and self-adjusting the pitch marking of steel pipe threads. It can automatically detect and self-adjust the pitch of the conveyor line when the steel pipe is coated with anti-corrosion coating. No manual operation is required, which improves the personal safety of equipment operators, increases the level of automation, reduces adjustment time, and improves production efficiency. Attached Figure Description

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0027] Figure 1 This is a side view of the conveying steel pipe of the conveying line of the present invention;

[0028] Figure 2 This is an unloaded isometric view of the conveyor line of the present invention;

[0029] Figure 3 This is an isometric view of the detection component of the present invention;

[0030] Figure 4 This is an isometric view of the paint spraying assembly of the present invention;

[0031] Figure 5 This is an isometric view of the conveying assembly of the present invention;

[0032] Figure 6 This is a flowchart of the control system of the present invention;

[0033] Figure 7This is a flowchart of the automatic pitch adjustment process of the present invention;

[0034] Figure 8 This is a schematic diagram illustrating the calibration of the ratio between the camera image distance and the actual distance according to the present invention.

[0035] In the diagram: Frame 1; Detection base 101; Spray painting base 102; Steel pipe 2; Detection assembly 3; Third motor 301; Second lead screw 302; Lifting support plate 303; Detection bracket 304; Second rangefinder 305; Camera 306; Second motor 307; Second guide rod 308; Third lead screw 309; First forward support 310; Main control box 4; Spray painting assembly 5; Spray painting control box 501; First motor 502; First lead screw 503; Spray painting bracket 504; Spray nozzle 505; First rangefinder 506; Second forward support 507; Conveying assembly 6; Reducer mounting plate 601; Rotary reducer 602; Conveying reducer 603; Conveying motor 604; Roller 605; Roller frame 606; Rotary motor 607; Connecting flange 608. Detailed Implementation

[0036] Example 1

[0037] like Figure 1-5 As shown, a device for detecting and self-adjusting the pitch marking of steel pipes includes a steel pipe 2 and a frame 1. A main control box 4 and a paint spraying control box 501 are fixed on the side of the frame 1. The steel pipe 2 is placed above the frame 1. Multiple conveying components 6 are provided between the steel pipe 2 and the frame 1. A movable detection component 3 and a paint spraying component 5 are provided on one side above one side of the frame 1.

[0038] In the preferred embodiment, the main control box 4 is equipped with a network switch and a PLC.

[0039] The main control box also houses a CU320 control unit, a PLC1500 CPU, a PLC1500 DI / DO module, a touch screen, a PC, PN communication cables, signal cables, power cables, etc. The control section consists of a network switch, a PLC1500 CPU, PLC1500 DI / DO modules, a PLC1500 AI module, a touch screen, and a PC. The network switch is connected to the push rod drivers of the pitch marking and pitch measuring sections, the CU320 control unit, and the PLC1500 CPU via PN communication lines. The PLC1500 CPU is connected to the PC via a PN communication line. The rangefinder is connected to the PLC1500 AI module via a signal line. The paint pump is connected to the PLC1500 DI / DO module via a signal line. The camera is connected to the PC via a network cable.

[0040] In the preferred embodiment, the plurality of conveying components 6 are symmetrically arranged at a certain angle on both sides of the bottom of the steel pipe 2.

[0041] In a preferred embodiment, the conveying assembly 6 is provided with a speed reducer mounting plate 601. One side of the speed reducer mounting plate 601 is fixed on the frame 1, and the other side is fixed with a rotary speed reducer 602. A rotatable roller frame 606 is provided above the rotary speed reducer 602, and a rotary motor 607 is fixed on one side of the rotary speed reducer 602.

[0042] The roller frame 606 has a rotatable roller 605 in the middle, a conveyor reducer 603 on one side of the roller frame 606, a connecting flange 608 between the conveyor reducer 603 and the roller frame 606, and a conveyor motor 604 fixed on one side of the conveyor reducer 603.

[0043] In a preferred embodiment, the roller 605 is made of wear-resistant rubber material, and the outer circumference of the roller 605 is provided with anti-slip texture.

[0044] In a preferred embodiment, the frame 1 is provided with a detection base 101 and a paint spraying base 102 on the side near the main control box 4.

[0045] In a preferred embodiment, a second forward support 507 is fixed above the paint spraying base 102. A first motor 502 is provided at one end of the second forward support 507. A first lead screw 503 is connected to the output shaft end of the first motor 502. A movable paint spraying bracket 504 is provided on the first lead screw 503. A spray nozzle 505 and a first rangefinder 506 are provided on the top of the paint spraying bracket 504.

[0046] In a preferred embodiment, the detection base 101 is provided with a first forward-moving bracket 310, one end of the first forward-moving bracket 310 is provided with a third motor 301, the output shaft of the third motor 301 is connected to a second lead screw 302, the second lead screw 302 is provided with a movable lifting support plate 303, the lower part of the lifting support plate 303 is provided with a second motor 307, the output shaft of the second motor 307 is connected to a third lead screw 309, the third lead screw 309 is provided with a liftable detection bracket 304, and the detection bracket 304 is provided with a second rangefinder 305 and a camera 306.

[0047] The detection assembly 3 comprises a camera 306, a second rangefinder 305, a second lead screw 302, a third motor 301, a third lead screw 309, a second motor 307, and a detection base 101. The camera 306 and the second rangefinder 305 are mounted on the top of the third lead screw 309 and the guide rod 308 via the same detection bracket 304. The third lead screw 309 is mounted on top of the second lead screw 302, which is installed perpendicular to the ground. The second lead screw 302 and the third lead screw 309 are installed at a 90-degree angle, and the third lead screw 309 is perpendicular to the surface of the steel pipe. The second lead screw 302 and the third lead screw 309 are connected to the third motor 301 and the second motor 307 respectively via cables. The third motor 301 and the second motor 307 are connected to a network switch via a PN communication line. The third lead screw 309 of the screw pitch detection section is vertically installed on a flat iron plate on the ground. The third lead screw 309 can be raised and lowered under the drive of the third motor 301. Depending on the pipe diameter, the target position for each adjustment is: bottom elevation of steel pipe 2 + (0.5 * current pipe diameter). This ensures that the camera is basically facing the center line of the side of steel pipe 2.

[0048] The second lead screw 302 of the pitch detection section will extend and retract under the drive of the third motor 301. The extension movement will bring it closer to the surface of the steel pipe 2, and the retraction movement will move it away from the surface of the steel pipe 2. Each time the shape is adjusted, the target position of the extension and retraction of the second lead screw 302 is the "distance between camera 306 and steel pipe 2" set on the touch screen interface. The measurement of this distance between camera 306 and the surface of steel pipe 2 is obtained by the second rangefinder 305.

[0049] The device for adjusting the angle of the conveyor rollers consists of a conveyor motor 604, a rotary motor 607, a conveyor controller, a rotary controller, a control unit, and related mechanical connecting parts.

[0050] Example 2

[0051] Further explanation in conjunction with Example 1, such as Figure 6 and Figure 8 The structure shown applies the adjustment method of the above-mentioned steel pipe pitch marking detection and self-adjustment device, which includes:

[0052] S1. Set parameters on the touch screen, including the diameter of steel pipe 2, the distance between nozzle 505 and steel pipe 2, the height of camera 306 from the ground, the distance between camera 306 and steel pipe 2, the process pitch distance, the allowable deviation range, and the preset angle value.

[0053] S2. After setting the distance between the nozzle 505 and the steel pipe 2, the first motor 502 drives the first rangefinder 506 and the nozzle 505 on the top of the paint spraying bracket 504 to move closer to the outer wall of the steel pipe 2. When the first rangefinder 506 reaches the set position, the first motor 502 stops driving.

[0054] S2. After setting the diameter of the steel pipe 2 and the position parameters of the camera, the second motor 307 drives the detection bracket 304 to rise to a position that is flush with half the diameter of the steel pipe 2. The third motor 301 drives the second rangefinder 305 and the camera 306 on the lifting support plate 303 to move closer to the outer wall of the steel pipe 2. When the second rangefinder 305 reaches the set position, the third motor 502 stops driving.

[0055] S3. After setting the deflection angle of roller 605, the rotary motor 607 controls the roller frame 606 to deflect to the preset angle, and the roller 605 abuts against the steel pipe 2 at a certain angle.

[0056] S4. When the surface of steel pipe 2 is painted, the conveyor motor 604 is started to drive the roller 605. Since the roller 605 has a deflection angle with steel pipe 2, the steel pipe 2 above will move forward at a constant speed. The spray nozzle 505 starts to spray paint and forms a spiral paint line on the surface of steel pipe 2.

[0057] S5. When the paint line enters the field of view of the camera 306, the camera 306 will transmit the image containing the paint line to the PC, extract the outline of the two paint lines, and then calculate the actual pitch distance value through the algorithm.

[0058] The algorithm is as follows:

[0059] 1. Image pixel distance to actual distance ratio calibration calculation: When the focal length of camera 306 is selected and the distance between camera 306 and steel pipe 2 is constant, calibration is performed once. This calibration ratio can then be used continuously without further calibration. First, set the "distance between camera and steel pipe" on the touch screen. Then, extend the second lead screw 302 to the set position. At this point, stop the rotation of steel pipe 2. On the part of steel pipe 2 directly opposite camera 306, symmetrically attach calibration grid paper along the side axis of steel pipe 2. (See...) Figure 8 The graph paper contains a 25mm x 25mm black square. Using software on a PC, the image distance between the left and right sides of this 25mm x 25mm black square can be obtained as X pixels (computer image distances are calculated in pixels, while actual physical distances are in millimeters). Therefore, the ratio Z = 25 / X.

[0060] 2. Pitch Calculation: After calibration, remove the calibration grid. During normal production, automatically position the camera 306 to the distance between the camera 306 and the surface of the steel pipe 2 during calibration. The image distance between the two paint lines obtained by the PC software is Mpixels. Therefore, the actual pitch corresponding to the two paint lines is: M*Z.

[0061] S6, the PC will compare the pitch data in the main control box 4 with the preset process pitch distance and allowable deviation range in S1. When the actual pitch exceeds the tolerance, the main control box 4 will give an angle correction signal to the control unit to control the rotary motor 607.

[0062] The relationship between the deflection angle and the pitch and drive roller diameter, i.e., the angle relationship formula:

[0063]

[0064] β - conveyor roller deflection angle (°),

[0065] Ф - Diameter of steel pipe (mm)

[0066] D - Steel pipe advance pitch (mm),

[0067] n_rotations - the number of times the steel pipe rotates within time t.

[0068] Ф wheel - conveyor roller diameter (mm),

[0069] V-circumference - circumferential rotational speed of the steel pipe (m / min)

[0070] V-axis - Axial rotational speed of the steel pipe (m / min)

[0071] The number of revolutions of the n-wheel-roller in time t;

[0072] When the measured pitch D differs from the set pitch D, the β value is revised with an accuracy of 0.2°, the drive roller angle is automatically adjusted, and the pitch is automatically remeasured.

[0073] S7. After correction, repeat steps S4 and S5 until the pitch measurement value falls within the process pitch distance range.

[0074] Example 3

[0075] Taking actual production as an example, using a 1219mm steel pipe, with a thread pitch of 120mm, a pipe diameter of 1219mm, a nozzle-to-pipe distance of 10mm, a camera-to-pipe distance of 500mm, and a camera height of 1409.5mm, the allowable thread pitch range is 115-125mm. Based on experience, the preset angle is 1.94°. These parameters are then entered into the touchscreen.

[0076] The device automatically adjusts the spray head and camera into position. After the camera is in position, the drive roller angle is automatically initially adjusted by clicking on the touchscreen. The adjustment is then observed. Next, a 1219mm steel pipe is moved to the measurement area. The pitch measurement is started by clicking on the touchscreen. During the rotation and forward movement of the steel pipe, the painting process is completed, the pitch measurement is finished, and the measurement data is fed back. When the automatically measured pitch range is 108-112mm, the device compares it with the set allowable pitch range of 115-125mm. If the pitch is found to be too small, the PLC1500 CPU sends a command to the rotary motor to increase the angle by 0.2°. The actual pitch is then measured again, and the comparison with the set pitch range continues. The PLC automatically corrects the pitch in 0.2° increments each time, repeating this process until the pitch is between 115-125mm, thus completing the automatic pitch adjustment.

[0077] 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. A device for detecting and self-adjusting the pitch mark of a steel pipe, comprising a steel pipe (2) and a frame (1), characterized in that: The side of the rack (1) is fixed with a total control box (4) and a paint spraying control box (501), a steel pipe (2) is placed above the rack (1), a plurality of conveying assemblies (6) are arranged between the steel pipe (2) and the rack (1), and one side of the upper side of the rack (1) is provided with a movable detection assembly (3) and a paint spraying assembly (5); The conveying assembly (6) is provided with a speed reducer mounting plate (601), one side of the speed reducer mounting plate (601) is fixed on the rack (1), the other side is fixed with a rotary speed reducer (602), the upper side of the rotary speed reducer (602) is provided with a rotatable roller frame (606), and one side of the rotary speed reducer (602) is fixed with a rotary motor (607); The middle of the roller frame (606) is provided with a rotatable roller (605), one side of the roller frame (606) is provided with a conveying speed reducer (603), a connecting flange (608) is arranged between the roller frame (606) and the conveying speed reducer (603), and one side of the conveying speed reducer (603) is fixed with a conveying motor (604); The rack (1) is provided with a detection base (101) and a paint spraying base (102) on the side close to the total control box (4); The second front moving support (507) is fixed above the paint spraying base (102), one end of the second front moving support (507) is provided with a first motor (502), the output shaft end of the first motor (502) is connected with a first lead screw (503), the first lead screw (503) is provided with a movable paint spraying support (504), and the top of the paint spraying support (504) is provided with a spray head (505) and a first distance meter (506); The detection base (101) is provided with a first front moving support (310), one end of the first front moving support (310) is provided with a third motor (301), the output shaft of the third motor (301) is connected with a second lead screw (302), the second lead screw (302) is provided with a movable lifting support plate (303), the lower side of the lifting support plate (303) is provided with a second motor (307), the output shaft of the second motor (307) is connected with a third lead screw (309), the third lead screw (309) is provided with a liftable detection support (304), and the detection support (304) is provided with a second distance meter (305) and a camera (306); The self-adjusting method is as follows: S1, setting parameters on the touch screen, including the diameter of the steel pipe (2), the distance between the spray head (505) and the steel pipe (2), the height of the camera (306) from the ground, the distance between the camera (306) and the steel pipe (2), the process pitch distance, the allowable deviation range, and the preset angle value; S2, after setting the distance between the spray head (505) and the steel pipe (2), the first motor (502) drives the first distance meter (506) and the spray head (505) on the top of the paint spraying support (504) to move close to the outer wall of the steel pipe (2), and the first motor (502) stops driving when the first distance meter (506) reaches the set position; S3, after setting the diameter of the steel pipe (2) and the camera position parameters, the second motor (307) drives the detection bracket (304) to rise to a position flush with half of the diameter of the steel pipe (2), and the third motor (301) drives the second range finder (305) and the camera (306) on the lifting plate (303) to approach the outer wall of the steel pipe (2). When the second range finder (305) reaches the set position, the third motor (301) stops driving; S4, after setting the deflection angle of the roller (605), the rotary motor (607) controls the roller frame (606) to deflect to the preset angle, and the roller (605) is deflected at a certain angle with the steel pipe (2); S5, the surface of the steel pipe (2) is painted, the conveying motor (604) is started to drive the roller (605), and because the roller (605) has a deflection angle with the steel pipe 2, the upper steel pipe (2) will move forward at a constant speed, the spray head (505) starts to spray paint and forms a spiral paint line on the surface of the steel pipe (2); S6, when the paint line enters the field of view of the camera (306), the camera (306) will transmit the image containing the paint line to the PC, and after extracting the contours of the two paint lines, the actual pitch distance value is calculated by algorithm; S7, the PC compares the pitch data in the total control box (4) with the preset process pitch distance and the allowable deviation range in S1, and when the actual pitch is out of tolerance, the total control box (4) will give an angle correction signal to the control unit to control the rotary motor (607); S8, after correction, steps S5 and S6 are repeated until the pitch measurement value falls within the process pitch distance interval.

2. The device for detecting and self-adjusting the pitch mark of a steel pipe according to claim 1, characterized in that: The total control box (4) is provided with a network switch and a PLC.

3. The device for detecting and self-adjusting the pitch marking of steel pipes according to claim 1, characterized in that: The plurality of conveying assemblies (6) are symmetrically arranged at both sides of the bottom of the steel pipe (2) at a certain angle.

4. The apparatus for detecting and self-adjusting the pitch of a steel pipe according to claim 1, wherein: The material of the roller (605) is wear-resistant rubber material, and the outer circle of the roller (605) is provided with anti-skid lines.

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