Coating thickness control device

Abstract

This invention relates to the field of anti-corrosion coating of steel pipes, and more particularly to a coating thickness control device, aiming to alleviate the technical problems of excessive pipe coating thickness and high anti-corrosion costs in related technologies. The coating thickness control device includes a coating mechanism and an auxiliary mechanism. The coating mechanism includes a pressure roller, a speed measuring element, and a first rotary drive assembly, wherein the first rotary drive assembly is drivenly connected to the pressure roller, and the speed measuring element is used to measure the speed of the pressure roller. The auxiliary mechanism includes an auxiliary roller and a second rotary drive assembly, wherein the auxiliary roller and the pressure roller are distributed parallel to each other, the second rotary drive assembly is drivenly connected to the auxiliary roller, and electrically connected to the speed measuring element. The second rotary drive assembly is configured to generate instantaneous acceleration in the auxiliary roller during weld coating operations. Through this coating thickness control device, the length of the polyethylene film can be changed, making its instantaneous length controllable, thereby changing its thickness.

Description

Technical Field

[0001] This invention relates to the field of anti-corrosion coating of steel pipes, and more particularly to a coating thickness control device. Background Technology

[0002] 3PE refers to polyethylene anti-corrosion coating, which consists of an epoxy powder coating as the bottom layer, an adhesive layer as the middle layer, and a polyethylene coating as the top layer. Polyethylene, as the 3PE surface layer material for pipes, possesses resistance to organic solvents, high mechanical strength and toughness, and excellent UV resistance and aging resistance.

[0003] Polyethylene is extruded using a screw extruder, and its extruded state is viscous. After being compacted by pressure rollers, it can be evenly wound onto the surface of a steel pipe. However, when it is applied to submerged arc welded pipes, especially straight seam submerged arc welded pipes, the thickness of the film will decrease drastically when the pressure rollers compact the polyethylene film at the outer weld seam because the straight seam submerged arc welded pipe has an outer weld seam extending along its axial direction and the outer weld seam has a certain excess height.

[0004] In recent years, with the improvement of pipeline construction standards, the quality standards for corrosion protection have also been continuously raised. The coating thickness at the external weld has been increased from no less than 70% of the pipe body thickness to 90%. Under these circumstances, the only way to meet the coating thickness requirements at the external weld is to increase the extrusion volume of polyethylene. However, this will cause the overall coating thickness of the pipe body to exceed the standard line, and at the same time, it will also lead to an increase in polyethylene material consumption, resulting in high corrosion protection costs. Summary of the Invention

[0005] The purpose of this invention is to provide a coating thickness control device to alleviate the technical problems in related technologies where the coating thickness of the pipe body exceeds the standard requirements and the anti-corrosion cost is high.

[0006] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows:

[0007] The coating thickness control device provided by the present invention includes: a coating mechanism and an auxiliary mechanism;

[0008] The coating mechanism includes a pressure roller, a speed measuring device, and a first rotary drive assembly, wherein the first rotary drive assembly is connected to the pressure roller in a transmission manner, and the speed measuring device is used to measure the speed of the pressure roller;

[0009] The auxiliary mechanism includes an auxiliary roller and a second rotary drive assembly, wherein the auxiliary roller and the pressure roller are distributed in parallel, the second rotary drive assembly is drivenly connected to the auxiliary roller and electrically connected to the speed measuring element, and the second rotary drive assembly is configured to cause the auxiliary roller to generate instantaneous acceleration under the coating weld condition.

[0010] Furthermore, the speed measuring element includes an encoder, which is connected to the end of the pressure roller.

[0011] Furthermore, the second rotary drive assembly includes a second rotary driver and a second coupling;

[0012] The output shaft of the second rotary driver is connected to one end of the second coupling, and the other end of the second coupling is connected to the auxiliary roller.

[0013] Furthermore, the coating thickness control device also includes a base plate;

[0014] The coating mechanism and the auxiliary mechanism are disposed on the upper surface of the base plate, wherein the auxiliary mechanism is slidably engaged with the base plate and can slide closer to or further away from the pressure roller in a direction perpendicular to the axis of the pressure roller.

[0015] Furthermore, the coating thickness control device also includes a linear drive assembly, which is disposed on the base plate and is connected to the auxiliary mechanism for driving the auxiliary mechanism to slide along a straight line.

[0016] Furthermore, the auxiliary mechanism also includes a movable roller seat;

[0017] The linear drive assembly is connected to the moving roller seat via a transmission connection.

[0018] The movable roller seat is slidably connected to the base plate;

[0019] The auxiliary roller is disposed on the movable roller seat, and both ends of the auxiliary roller are rotatably engaged with the movable roller seat.

[0020] Furthermore, the base plate is provided with a slide rail, and the extension direction of the slide rail is perpendicular to the axis of the pressure roller;

[0021] The movable roller seat slides in conjunction with the slide rail.

[0022] Furthermore, the linear drive assembly includes a ball screw and a handwheel;

[0023] In the ball screw, the length direction of the screw is consistent with the extension direction of the slide rail, both ends of the screw are rotatably engaged with the base plate, and the nut is connected to the movable roller seat;

[0024] The handwheel is connected to the end of the screw.

[0025] Furthermore, the coating thickness control device also includes a lifting drive assembly;

[0026] The lifting drive assembly is connected to the base plate and configured to drive the base plate to lift and lower during coating operations, so that the pressure roller moves closer to or away from the steel pipe.

[0027] Furthermore, the lifting drive assembly includes a lifting cylinder;

[0028] In the sliding direction of the auxiliary mechanism, the end of the base plate near the auxiliary mechanism is hinged to the ground;

[0029] The lifting cylinder is hinged between the end of the base plate near the coating mechanism and the ground.

[0030] In summary, the technical effects achieved by the coating thickness control device provided by this invention are as follows:

[0031] The coating thickness control device provided by the present invention includes a coating mechanism and an auxiliary mechanism; the coating mechanism includes a pressure roller, a speed measuring element, and a first rotary drive assembly, wherein the first rotary drive assembly is drivenly connected to the pressure roller, and the speed measuring element is used to measure the speed of the pressure roller; the auxiliary mechanism includes an auxiliary roller and a second rotary drive assembly, wherein the auxiliary roller and the pressure roller are distributed in parallel, the second rotary drive assembly is drivenly connected to the auxiliary roller and electrically connected to the speed measuring element, and the second rotary drive assembly is configured to cause the auxiliary roller to generate instantaneous acceleration under the condition of coating the weld seam.

[0032] In this device, the auxiliary roller and the pressure roller are arranged in parallel. Driven by the second rotary drive assembly, the auxiliary roller can guide the polyethylene film extruded by the screw extruder along the tangential direction of the steel pipe to the pressure roller. After the polyethylene film passes around the auxiliary roller and is transferred to the pressure roller, the pressure roller will crush the polyethylene film and wrap it around the surface of the steel pipe through the drive of the first rotary drive assembly, thereby completing the coating application.

[0033] During the coating process, the rotation speed measuring device measures the rotation speed of the pressure roller and sends the speed information to the second rotary drive assembly. The second rotary drive assembly then controls the rotation speed of the auxiliary roller. In the non-weld seam area, the linear velocity of the auxiliary roller is consistent with that of the pressure roller. In this way, the length of the polyethylene film between the auxiliary roller and the steel pipe remains constant, allowing it to be evenly wound and compacted onto the steel pipe by the pressure roller. When encountering the weld seam, the auxiliary roller generates instantaneous acceleration. At this time, the linear velocity of the auxiliary roller is momentarily greater than that of the pressure roller. As a result, the force pulling the polyethylene film between the two rollers decreases, causing the length of the polyethylene film between the auxiliary roller and the steel pipe to increase instantaneously, thus increasing the thickness. After being compacted onto the steel pipe, the coating thickness meets the standard requirements.

[0034] Therefore, compared with the existing technology, this coating thickness control device can change the length of the polyethylene film during the coating process, making its instantaneous length controllable, thereby achieving thickness adjustment. After the polyethylene film is compacted at the weld, the coating thickness will not be drastically reduced due to the presence of weld excess height, which can meet the standard requirements and also reduce costs. Attached Figure Description

[0035] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram illustrating the application of the coating thickness control device provided in an embodiment of the present invention.

[0037] Figure 2 This is a top view of the coating thickness control device provided in an embodiment of the present invention.

[0038] Icons: 100 - Pressure roller; 200 - Rotation speed measuring element; 300 - Auxiliary roller; 400 - Second rotary drive; 500 - Base plate;

[0039] 600 - Linear drive assembly; 610 - Ball screw; 620 - Handwheel;

[0040] 700 - Moving roller seat; 800 - Slide rail;

[0041] 900 - Lifting drive assembly; 910 - Lifting cylinder; 920 - Fixed hinge;

[0042] 1000 - Steel pipe; 1100 - Ground; 1200 - Fixed roller seat; 1300 - Screw extruder. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0045] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0046] In recent years, with the improvement of pipeline construction standards, the quality standards for corrosion protection have also been continuously raised. The coating thickness at the external weld has been increased from no less than 70% of the pipe body thickness to 90%. Under these circumstances, the only way to meet the coating thickness requirements at the external weld is to increase the extrusion volume of polyethylene. However, this will cause the overall coating thickness of the pipe body to exceed the standard line, and at the same time, it will also lead to an increase in polyethylene material consumption, resulting in high corrosion protection costs.

[0047] In view of this, the present invention provides a coating thickness control device, including a coating mechanism and an auxiliary mechanism; the coating mechanism includes a pressure roller 100, a speed measuring element 200, and a first rotary drive assembly, wherein the first rotary drive assembly is drivenly connected to the pressure roller 100, and the speed measuring element 200 is used to measure the speed of the pressure roller 100; the auxiliary mechanism includes an auxiliary roller 300 and a second rotary drive assembly, wherein the auxiliary roller 300 and the pressure roller 100 are distributed in parallel, the second rotary drive assembly is drivenly connected to the auxiliary roller 300 and electrically connected to the speed measuring element 200, and the second rotary drive assembly is configured to cause the auxiliary roller 300 to generate instantaneous acceleration under the condition of coating the weld seam.

[0048] In this device, the auxiliary roller 300 and the pressure roller 100 are arranged in parallel. Driven by the second rotary drive assembly, the auxiliary roller 300 can guide the polyethylene film extruded by the screw extruder 1300 along the tangential direction of the steel pipe 1000 and guide it to the pressure roller 100. After the polyethylene film passes around the auxiliary roller 300 and is conveyed to the pressure roller 100, the pressure roller 100 will crush the polyethylene film and wrap it around the surface of the steel pipe 100 through the drive of the first rotary drive assembly, thereby completing the coating application.

[0049] During the coating process, the rotation speed measuring device 200 measures the rotation speed of the pressure roller 100 and sends the rotation speed information to the second rotary drive assembly. Then, the second rotary drive assembly controls the rotation speed of the auxiliary roller 300. In the non-weld seam area, the linear velocity of the auxiliary roller 300 is consistent with the linear velocity of the pressure roller 100. In this way, the length of the polyethylene film between the auxiliary roller 300 and the steel pipe 1000 remains constant, allowing it to be evenly wound and compacted onto the steel pipe 1000 by the pressure roller 100. When encountering the weld seam, the auxiliary roller 300 generates instantaneous acceleration. At this time, the linear velocity of the auxiliary roller 300 is instantaneously greater than the linear velocity of the pressure roller 100. As a result, the force pulling the polyethylene film between the two rollers decreases, causing the length of the polyethylene film between the auxiliary roller 300 and the steel pipe 1000 to increase instantaneously, thereby increasing the thickness. After being compacted onto the steel pipe 1000, the coating thickness meets the standard requirements.

[0050] Therefore, compared with the existing technology, this coating thickness control device can change the length of the polyethylene film during the coating process, making its instantaneous length controllable, thereby achieving thickness adjustment. After the polyethylene film is compacted at the weld, the coating thickness will not be drastically reduced due to the presence of weld excess height, which can meet the standard requirements and also reduce costs.

[0051] The following combination Figure 1 and Figure 2 The structure and shape of the coating thickness control device provided in this embodiment will be described in detail:

[0052] In one embodiment of this application, reference is made to Figure 2 The first rotary drive assembly includes a first rotary driver and a first coupling. The output shaft of the first rotary driver is connected to one end of the first coupling, and the other end of the first coupling is connected to the pressure roller 100. The second rotary drive assembly includes a second rotary driver 400 and a second coupling. The output shaft of the second rotary driver 400 is connected to one end of the second coupling, and the other end of the second coupling is connected to the auxiliary roller 300. The rotary driver here can preferably be a servo motor. This design achieves precise control of the rotation of the auxiliary roller 300 and the pressure roller 100, while ensuring a fast response when instantaneous acceleration is required, thus guaranteeing the coating effect.

[0053] Regarding the 200 speed measuring element, specifically:

[0054] The speed measuring element 200 may be a speed sensor, such as a Hall effect, magnetoelectric, or photoelectric sensor, or an encoder, or other electronic components capable of measuring speed.

[0055] Preferably, an encoder is used here, and the encoder is connected to the end of the pressure roller 100 via a coupling. When the pressure roller 100 rotates, the encoder rotates synchronously, and the rotational speed of the pressure roller 100 is measured and converted into a corresponding pulse value by the PLC, which is then sent to the corresponding servo motor. During normal operation, the servo motor keeps the auxiliary roller 300 at the same linear speed as the pressure roller 100. When the weld seam arrives, the PLC outputs a pulse value exceeding the value measured by the encoder to the servo motor, causing it to accelerate. The auxiliary roller 300 generates instantaneous acceleration, changing the length of the polyethylene film. It should be noted that the acceleration pulse value of the servo motor is manually input on the touchscreen, and the input value can be flexibly adjusted according to the required compensation amount.

[0056] Further reference Figure 1 and Figure 2 The coating thickness control device also includes a base plate 500; the coating mechanism and the auxiliary mechanism are disposed on the upper surface of the base plate 500, and the auxiliary mechanism is slidably engaged with the base plate 500 and can slide close to or away from the pressure roller 100 in a direction perpendicular to the axis of the pressure roller 100.

[0057] Continue to refer to Figure 1 and Figure 2 The coating mechanism and auxiliary mechanism are distributed on the left and right sides. The auxiliary mechanism is slidably connected to the base plate 500 and can slide on the base plate 500 in the left and right direction to move closer to or further away from the coating mechanism. During the sliding process, the auxiliary roller 300 slides closer to or further away from the pressure roller 100, and the distance between the two decreases or increases accordingly. In this way, the range of change of the length of the polyethylene film is adjusted. That is, when the distance between the two is relatively small, the range of change of the length of the polyethylene film is small, and correspondingly, the changeable thickness of the polyethylene film is small. When the distance between the two is relatively large, the range of change of the length of the polyethylene film is large, and correspondingly, the changeable thickness of the polyethylene film is large. This achieves precise compensation for welds with different excess heights and improves the applicability of the coating thickness control device.

[0058] Regarding the auxiliary and coating mechanisms, specifically:

[0059] refer to Figure 1 and Figure 2 The auxiliary mechanism also includes a movable roller seat 700. Two parallel and laterally extending slide rails 800 are provided on the base plate 500, and the movable roller seat 700 slides in conjunction with the slide rails 800. The two ends of the auxiliary roller 300 are fixed to the movable roller seat 700 via bearing seats and can rotate around its own axis. The coating mechanism also includes a fixed roller seat 1200, which is fixed to the base plate 500. The two ends of the pressure roller 100 are fixed to the fixed roller seat 1200 via bearing seats and can rotate around its own axis.

[0060] In normal use, the distance between the auxiliary roller 300 and the pressure roller 100 does not need to be adjusted in the coating thickness control device. When replacing with other steel pipes 1000, such as those with a changed diameter or spiral weld, the roller seat 700 can be adaptively slidably moved, sliding left and right on the slide rail 800. This synchronously drives the auxiliary roller 300 to move left and right, correspondingly decreasing or increasing the distance between the auxiliary roller 300 and the pressure roller 100, thus adjusting the range of changes in the polyethylene film length. With this design, the device can coat steel pipes 1000 of different diameters while ensuring the accuracy of the coating area, making the coating thickness meet the corresponding standard requirements.

[0061] Further reference Figure 1 and Figure 2 The coating thickness control device also includes a linear drive component 600, which is disposed on the base plate 500 and is connected to the auxiliary mechanism for transmission, so as to drive the auxiliary mechanism to slide in a straight line and realize the adjustment of the distance between the auxiliary roller 300 and the pressure roller 100.

[0062] In one embodiment of this application, reference continues to be made to... Figure 1 and Figure 2 The linear drive assembly 600 includes a ball screw 610 and a handwheel 620. In the ball screw 610, the length direction of its screw is consistent with the extension direction of the slide rail 800, and both ends of the screw are rotatably engaged with the base plate 500. The nut is connected to the movable roller seat 700. The handwheel 620 is connected to the end of the screw.

[0063] Specifically, the screw is positioned between two slide rails 800 and is parallel to the slide rails 800. Both ends of the screw are fixed to the base plate 500 via bearing seats. The nut is fixedly connected to the bottom of the movable roller seat 700. In practical application, first, the handwheel 620 is rotated, and the screw rotates synchronously. The nut, threaded with the screw, moves axially along the screw under the drive of the screw and the constraint of the movable roller seat 700. This causes the movable roller seat 700 to slide on the slide rails 800, thereby adjusting the distance between the auxiliary roller 300 and the pressure roller 100, reducing or increasing the range of change in the length of the polyethylene film.

[0064] In other embodiments, the linear drive assembly 600 may be a linear drive component, such as a cylinder, an electric cylinder, or a linear motor.

[0065] Further reference Figure 1 The coating thickness control device also includes a lifting drive assembly 900; the lifting drive assembly 900 is connected to the base plate 500 and is configured to drive the base plate 500 to lift and lower during the coating process, so that the pressure roller 100 moves closer to or away from the steel pipe 1000.

[0066] Specifically, with Figure 1For example, driven by the lifting drive assembly 900, the base plate 500 will rise and fall, and the coating mechanism mounted on the base plate 500 will rise and fall synchronously, thereby causing the pressure roller 100 to move up and down to move closer to or away from the steel pipe 1000, thus achieving coating of the steel pipe 1000, or removal after coating, facilitating replacement of the steel pipe 1000. Furthermore, by controlling the rising height of the pressure roller 100, the distance between the pressure roller 100 and the steel pipe 1000 is controlled, thereby making the coating thickness control device applicable to steel pipes 1000 of different specifications, increasing its application range.

[0067] It should be noted that the lifting here can be the entire base plate 500 moving up and down longitudinally, or one end of the base plate 500 can be relatively fixed while the other end rotates.

[0068] More preferably, this embodiment adopts the latter, correspondingly, such as Figure 1 As shown, the lifting drive assembly 900 includes a lifting cylinder 910; in the sliding direction of the auxiliary mechanism, the end of the base plate 500 near the auxiliary mechanism is hinged to the ground 1100; the lifting cylinder 910 is hinged between the end of the base plate 500 near the coating mechanism and the ground 1100.

[0069] For details, please refer to Figure 1 and Figure 2 The middle of the left end of the base plate 500 is hinged to the output end of the lifting cylinder 910 via a fixed hinge 920. The cylinder body of the lifting cylinder 910 is hinged to the ground 1100 via another fixed hinge 920. The two sides of the right end of the base plate 500 are hinged to the ground 1100 via two fixed hinges 920. With this design, when the lifting cylinder 910 is activated, the left end of the base plate 500 will rotate around the hinge axis of its right end, thereby driving the coating mechanism to rotate synchronously, so that the pressure roller 100 can be raised and lowered.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A coating thickness control device, characterized in that, include: Coating mechanism and auxiliary mechanism; The coating mechanism includes a pressure roller (100), a speed measuring element (200), and a first rotary drive assembly, wherein the first rotary drive assembly is connected to the pressure roller (100) in a transmission manner, and the speed measuring element (200) is used to measure the speed of the pressure roller (100); The auxiliary mechanism includes an auxiliary roller (300) and a second rotary drive assembly, wherein the auxiliary roller (300) and the pressure roller (100) are distributed in parallel, the second rotary drive assembly is drivenly connected to the auxiliary roller (300) and electrically connected to the speed measuring element (200), and the second rotary drive assembly is configured to cause the auxiliary roller (300) to generate instantaneous acceleration under the condition of coating weld seam; The coating thickness control device also includes a base plate (500); The coating mechanism and the auxiliary mechanism are disposed on the upper surface of the base plate (500), and the auxiliary mechanism is slidably engaged with the base plate (500) and can slide close to or away from the pressure roller (100) in a direction perpendicular to the axis of the pressure roller (100); The coating thickness control device further includes a linear drive assembly (600), which is disposed on the base plate (500) and is connected to the auxiliary mechanism for transmission to drive the auxiliary mechanism to slide along a straight line.

2. The coating thickness control device according to claim 1, characterized in that, The rotational speed measuring element (200) includes an encoder connected to the end of the pressure roller (100).

3. The coating thickness control device according to claim 1, characterized in that, The second rotary drive assembly includes a second rotary driver (400) and a second coupling; The output shaft of the second rotary drive (400) is connected to one end of the second coupling, and the other end of the second coupling is connected to the auxiliary roller (300).

4. The coating thickness control device according to claim 1, characterized in that, The auxiliary mechanism also includes a movable roller seat (700); The linear drive assembly (600) is connected to the movable roller seat (700) in a transmission connection; The movable roller seat (700) is slidably connected to the base plate (500); The auxiliary roller (300) is disposed on the movable roller seat (700), and both ends of the auxiliary roller (300) are rotatably engaged with the movable roller seat (700).

5. The coating thickness control device according to claim 4, characterized in that, The base plate (500) is provided with a slide rail (800), and the extension direction of the slide rail (800) is perpendicular to the axis of the pressure roller (100); The movable roller seat (700) is slidably engaged with the slide rail (800).

6. The coating thickness control device according to claim 5, characterized in that, The linear drive assembly (600) includes a ball screw (610) and a handwheel (620); In the ball screw (610), the length direction of the screw is consistent with the extension direction of the slide rail (800), both ends of the screw are rotatably engaged with the base plate (500), and the nut is connected to the movable roller seat (700). The handwheel (620) is connected to the end of the screw.

7. The coating thickness control device according to claim 1, characterized in that, The coating thickness control device also includes a lifting drive assembly (900); The lifting drive assembly (900) is connected to the base plate (500) and configured to drive the base plate (500) to lift and lower during coating operations, so that the pressure roller (100) moves closer to or away from the steel pipe (1000).

8. The coating thickness control device according to claim 7, characterized in that, The lifting drive assembly (900) includes a lifting cylinder (910); In the sliding direction of the auxiliary mechanism, the bottom plate (500) is hinged to the ground (1100) at one end near the auxiliary mechanism; The lifting cylinder (910) is hinged between the end of the base plate (500) near the coating mechanism and the ground (1100).

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