Automatic fly cutting device for large-diameter thick-wall spiral welded pipe and sizing control method of automatic fly cutting device

Abstract

An automatic fly-cutting device for a large-diameter thick-wall spiral welded pipe comprises a synchronizing mechanism, a cutting device and a tool setting mechanism, and the synchronizing mechanism is used for abutting against the spiral welded pipe, removing the rotation component of the spiral welded pipe and copying the axial movement component V axis of the spiral welded pipe; the synchronizing mechanism is selectively connected with the spiral welded pipe in a coupling mode through an abutting device pair, and the spiral welded pipe is transmitted to the synchronizing mechanism in a sliding-free mode to achieve synchronization. The cutting device is fixedly arranged on the synchronizing mechanism and used for cutting the spiral welded pipe when the spiral welded pipe rotates. The tool setting mechanism comprises a follow-up detection module and a tool setting module, and the follow-up detection module is arranged in front of the spiral welded pipe and used for detecting arrival of the end of the steel pipe and triggering synchronous following; the tool setting module is arranged on the cutting device and used for accurately aligning the cutting point of the cutting torch to the position with the fixed length L0 away from the end of the steel pipe, and the tool setting module is simple and practical.

Description

Technical Field

[0001] The invention relates to the technical field of spiral welded pipe forming, and in particular to an automatic fly-cutting device for large-diameter thick-walled spiral welded pipes and a length control method thereof. Background Art

[0002] Fly-cutting machines are widely used in spiral welded pipe production lines. They measure and cut continuously online the spiral welded pipe as it is being formed. Steel plates are bent into a spiral shape by the forming machine, and the weld seams are welded while the formed pipe rotates about its central axis. The pipe not only rotates circumferentially but also moves forward along its axis, meaning that any point on the pipe undergoes a spiral motion. This requires two key considerations: synchronization with the workpiece and cutting the workpiece. Ideally, the cut surface should be perpendicular to the pipe axis, with the start and end points of the cut slit coinciding. Large-diameter spiral welded pipes, with their greater rigidity, place high demands on the synchronization of the fly-cutting machine. Otherwise, the cuts will be skewed or the start and end points of the cut slits will not align, with the misalignment sometimes reaching 1 to 3 cm. In practice, the misalignment and starting point errors should be kept within the cut slit width.

[0003] The existing technology uses a synchronization mechanism to solve the problem of synchronization with the workpiece. The synchronization mechanism often uses a single wheel to apply pressure and tighten through a cylinder. The spiral welded pipe has a roundness tolerance and a weld ridge. The tension wheel presses the surface of the welded pipe in point contact, which is easy to slip and has indentations. Jilin Jinghua Pipe Manufacturing Co., Ltd. discloses an automatic flying cutting trolley on a spiral welded pipe production line (CN109865926A, publication date: June 11, 2019). The tension wheel 21 is driven by the oil cylinder on the other side of the rotating mounting rod 31 to abut against the outer peripheral surface of the spiral welded pipe 11 to achieve synchronization. The tension wheel 21 rolls in a point contact state. Because the tension wheel 21 passes over the weld ridge, the friction force of the trolley driven by the rotation of the welded pipe along the axis of the welded pipe will suddenly change, which is prone to displacement in the direction of the pipe axis, resulting in the starting point and end point of the cutting seam not coinciding.

[0004] The existing technology usually adopts a plasma welding torch or a laser welding torch cutting device, which is mainly used for sizing and cutting. For sizing, the length of the steel pipe is precisely controlled. Cutting begins after the cutting torch is sized, but it is usually not possible to strictly control the coincidence of the starting and ending points of the cutting seam, and the cutting surface is perpendicular to the axis of the welded pipe. Shandong Hongang Automation Technology Co., Ltd. discloses a spiral tube laser tracking online laser cutting device (CN210967513U, publication date: July 10, 2020), including a servo cutting device 2, the servo cutting device 2 includes a beam 22, the beam 22 is arranged on the light rail 21, and is controlled by a servo motor connected to the controller, a laser tracking track 23 is provided on the beam 22 and under the pipe workpiece 3, a servo laser tracker 24 is provided on the laser tracking track 23, a cross-arm manipulator 26 is provided at one end of the beam 22, and a cutting torch 25 is provided on the cross-arm manipulator 26. A pipe outlet speed measuring device 6 is provided at the outlet of the pipe reel 1 , and a length sensor 4 is provided at the end of the support 5 away from the servo cutting device 2 . The pipe workpiece 3 rolled out by the pipe reel 1 rotates and moves linearly on the support 5 . When the pipe workpiece 3 reaches the specified set length, the length sensor 4 detects that the set length has been reached, and the servo cutting device 2 begins operation. The pipe outlet linear velocity measuring device 6 measures the tangential velocity V1 and linear velocity V2 of the pipe outlet and transmits these values ​​to the controller. After the length sensor 4 detects that the set length has been reached, the servo cutting device 2 begins operation. The crossbeam 22, mounted on the light rail 21, moves linearly at the same speed as the pipe workpiece. The cutting torch 25 begins operation and begins cutting. The servo laser tracker 24 illuminates an arc with the cutting start point as the point and the pipe workpiece 3 as the diameter. The servo laser tracker 24 uses the cutting start point as the positioning point and performs a semicircular motion on the laser tracking track 23 for semicircular positioning. It tracks the cutting start point to 180° and calibrates the flatness of the cutting torch 25. After cutting is completed, the servo cutting device 2 returns to the positioning starting point. It performs a semicircular motion on the laser tracking track for semicircular positioning, tracks the cutting start point to 180°, and calibrates the flatness of the cutting torch 25. However, the above solution has a fundamental flaw: the laser tracker 24 and the cutting torch are both fixed to the carriage. If the cutting torch 25 is found to be deviated, the cutting torch 25 can only move up and down within a fixed vertical plane. Therefore, it is impossible to correct the flatness of the cutting torch. Even if the cutting torch 25 can be moved freely, it is still unknown how to correct the flatness of the cutting torch.

[0005] Therefore, this field urgently needs an automated flying cutting device and control method for large-diameter thick-walled spiral welded pipes, so as to cut out precise pipe lengths, make the starting and ending points of the cutting seam coincide, and make the cutting surface perpendicular to the axis of the welded pipe, that is, the cut pipe end is a closed circle perpendicular to the center line of the welded pipe. In addition, how to miniaturize the cutting device for large-diameter pipes has become a key problem that the traditional spiral welded pipe forming production line urgently needs to overcome. Summary of the Invention

[0006] In response to the defects existing in the above-mentioned prior art, the purpose of the present invention is to provide an automatic flying cutting device for continuously formed spiral welded pipes and a length control method thereof. The present application solves at least one of the following technical problems: 1. Accurate pipe length; 2. Controlling the coincidence of the starting point and the end point of the cutting seam, and the cutting surface is perpendicular to the axis of the welded pipe, and the perpendicularity of the incision end face to the axis of the welded pipe is controlled within 3 mm; 3. Miniaturization of the cutting device.

[0007] The object of the present invention is achieved in this way:

[0008] An automatic fly cutting device for large diameter thick wall spiral welded pipes, comprising

[0009] The synchronization mechanism is located below the continuously formed spiral welded pipe and is used to abut the spiral welded pipe and remove its rotational component to replicate its axial movement component V 轴 The synchronization mechanism includes a synchronization trolley and a pair of abutments. The abutment pairs are symmetrically arranged on both sides of the spiral welded pipe and can be selectively coupled to connect the spiral welded pipes, transmitting the linear movement of the spiral welded pipe to the synchronization trolley without sliding to achieve synchronization.

[0010] A cutting device, which is fixed on the synchronization mechanism and includes a cutting torch for cutting the spiral welded pipe when the spiral welded pipe rotates;

[0011] The tool setting mechanism includes a detection module and a tool setting module. The detection module is located in front of the spiral welded pipe to detect the arrival of the steel pipe end and trigger synchronous following. The tool setting module is located in the cutting device to accurately align the cutting point of the cutting torch at a fixed length L0 from the end of the steel pipe.

[0012] Furthermore, the abutment pair includes an elastic pressure belt and a support chain belt, and the support chain belt is arranged on the outside of the elastic pressure belt; the elastic pressure belt includes a concave roller frame, and the concave roller frame is provided with a top roller, a bottom roller one, and a bottom roller two, and the circulating elastic belt is rolled between the top roller, the bottom roller two, and the bottom roller one.

[0013] Furthermore, the support chain includes a top support roller, a bottom support roller and a tension roller, and the circulating support chain is connected between the top support roller, the tension roller and the bottom support roller; an L-shaped rod 1 is rotatably provided between the top support roller and the tension roller, and an L-shaped rod 2 is provided between the bottom support roller and the tension roller. The L-shaped rod 1 and the L-shaped rod 2 are driven by a driving source to switch the top support roller and the bottom support roller between a retreat position and a pressing position. The pressing position is the position where the support chain is pressed against the outer circumference of the spiral welded pipe through an elastic pressure belt, and the retreat position is the position where the support chain and the elastic pressure belt leave the outer circumference of the spiral welded pipe.

[0014] Furthermore, the abutment pair can be selectively coupled to connect the spiral welded pipe W as follows: the two elastic pressure belts are simultaneously pressed on the outer circumference of the spiral welded pipe W through the corresponding support chain belts. Specifically, the driving source drives the top support roller and the bottom support roller to move from the retreat position to the pressing position. In the pressing position, the top support roller and the bottom support roller respectively apply the same and constant pressing force to the outer circumference of the spiral welded pipe through the elastic pressure belts.

[0015] Furthermore, the tool setting mechanism also includes a rail trolley, and the detection module is arranged on the rail trolley, which is used to detect whether the end of the steel pipe has arrived and synchronously follow the end of the steel pipe. The detection module includes a head tracker and a laser receiver. The rail trolley is provided with a follower rod perpendicular to the central axis of the spiral welded pipe. The head tracker and the laser receiver are located in the same vertical plane and are fixed on the follower rod at intervals up and down. The rail trolley is driven by a driving source and can move along the guide rail with the same axial component V as the spiral welded pipe W. 轴 Tracking movement at the same speed and direction.

[0016] Furthermore, a tool setting module is provided on the cutting device, and the tool setting module includes a laser emitter and a driving source. The laser emitter and the cutting torch are located in the same vertical plane and are fixed on the synchronization rod of the synchronization trolley with upper and lower intervals. The laser emission is aligned with the laser reception in a direction parallel to the central axis of the spiral welded pipe W; the bottom of the synchronization rod is provided on the synchronization trolley by sliding along the slide rail through a slider, and the slider is connected to the driving source.

[0017] Furthermore, the support chain belt includes a bottom support pressure roller and a circulating support chain belt, the support chain belt is rollingly arranged between the bottom support pressure roller and the top roller, and the support chain belt is stacked on one side of the elastic belt; the upper part of the concave roller frame is arranged on the crossbeam frame, and the bottom is inclined on the bottom inclined frame, the top roller is slidingly arranged on the crossbeam frame, and the bottom support pressure roller is slidingly arranged on the bottom inclined frame, and the top roller and the bottom support pressure roller are respectively connected to the driving source.

[0018] A length control method for an automatic fly-cutting device for large-diameter thick-wall spiral welded pipes comprises the following steps:

[0019] S0 fixed length detection

[0020] The head tracker detects whether the steel pipe end passes through the fixed length detection cycle at a fixed time. The cycle time is t 隔 Can be set; the cycle starts, detects whether the end of the steel pipe has passed? If the head tracker detects that the end of the steel pipe has not reached the head tracker position, the timing time t 检 =0, timing starts, when t 检 =t 隔 After that, return to the beginning of the loop; if the head tracker detects that the end of the steel pipe reaches the head tracker, the loop ends and executes S1;

[0021] S1 triggers tracking and synchronization simultaneously

[0022] The measuring module is initialized and the driving source is started, driving the measuring module to move along the guide rail with the same axial movement component V as the spiral welded pipe W. 轴 The device moves forward in the same direction and at the same speed; at the same time, the abutment pair of the synchronization mechanism starts coupling and connects the spiral welded pipe W;

[0023] S2 fixed length tool setting

[0024] The tool setting module starts tool setting and moves the cutting torch to the fixed length L0 according to the difference ⊿L between the actual measured length L1 and the fixed length L0;

[0025] S3 cutting

[0026] The cutting torch of the cutting device ignites and cuts until the entire circumference of the steel pipe is cut off.

[0027] Furthermore, step S2 is specifically as follows: repetition number i=0, ① tool setting movement: the laser emits a laser beam, the laser receives a laser beam, and the actual measured length L1 of the steel pipe is measured. According to the difference ⊿L between the actual measured length L1 and the fixed length L0, the driving source can drive the cutting torch to catch up and move to the fixed length L0; ② verify the fixed length, the laser emits a laser beam again, the laser receives a laser beam again, and the actual measured length L1 of the steel pipe is measured, and whether L1 is equal to L0 is checked; if equal and i≤10, then end; if not equal, then i=i+1, and execute step ①.

[0028] Furthermore, between step S1 and step S2, the

[0029] Step S11: Alignment and Calibration

[0030] The head tracker is a camera, which is installed horizontally and flushly along the centerline axis of the spiral welded pipe. It can measure the longest endpoint A and the shortest endpoint B of the edge of the steel pipe close to the head tracker after one rotation; calculate the axial distance ⊿B between the laser receiver and the lowest endpoint B, and the driving source drives the measurement module to align the laser receiver to the shortest endpoint B.

[0031] An automatic fly-cutting device for large-diameter, thick-walled spiral welded pipes and a sizing control method thereof are disclosed. Abutments are arranged axially symmetrically, and an elastic pressure belt cooperates with a support chain belt to abut the outer circumference of the steel pipe, preventing axis deviation. After synchronization, the measuring module of the sizing mechanism cooperates with the tool setting module to achieve actual sizing, resulting in high sizing accuracy and great practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a front view of a synchronization mechanism in a retracted position of a first embodiment of an automatic fly-cutting device for large-diameter thick-walled spiral welded pipe according to the present invention;

[0033] Figure 2This is a front view of a synchronization mechanism in an abutment position of Example 1 of an automatic fly-cutting device for large-diameter thick-walled spiral welded pipes according to the present invention;

[0034] Figure 3 This is a schematic diagram of a tool setting mechanism of Example 1 of an automatic fly-cutting device for large-diameter, thick-walled spiral welded pipes according to the present invention;

[0035] Figure 4 This is a flow chart of a length control method of embodiment 1 of an automatic fly-cutting device for large-diameter thick-walled spiral welded pipes of the present invention;

[0036] Figure 5 This is a front view of a synchronization mechanism located at an abutment position of Example 2 of an automatic fly-cutting device for large-diameter thick-walled spiral welded pipes according to the present invention.

[0037] Figure 6 This is a front view of a synchronization mechanism in a retracted position of a second embodiment of an automatic fly-cutting device for large-diameter thick-walled spiral welded pipe according to the present invention;

[0038] Figure 7 This is a second embodiment of an automatic fly-cutting device for a large-diameter thick-walled spiral welded pipe according to the present invention. Figure 4 AA cross-sectional view.

[0039] Reference numerals in the above figures:

[0040] 10 synchronization mechanism, 11 synchronization trolley, 12 abutment pair

[0041] 20 cutting device, 21 cutting torch mechanism, 22 cutting torch

[0042] 30 elastic pressure belt, 31 concave roller frame, 32 top roller, 33 bottom roller 1, 34 bottom roller 2, 35 elastic belt

[0043] 40 support chain, 41 top support roller, 42 bottom support roller, 43 support chain, 44 tension roller

[0044] 400 support chain, 401 crossbeam frame, 402 bottom support roller, 403 support chain, 404 bottom inclined frame

[0045] 50 tool setting mechanism, 51 follow-up measurement module, 52 tool setting module, 53 track car, 54 head tracker, 55 laser receiver, 56 follower rod, 57 laser transmitter, 58 direct drive source, 59 synchronization rod

[0046] 60 Symmetrical drive 2, 61 Screw nut pair, 62 Variable axis driven, 63 Positive and negative thread screw, 64 Middle section screw, 65 Vertical shift axis, 66 Worm gear, 67 Nut

[0047] 70 Symmetrical drive 1, 71 L-shaped rod pair, 72 Equal length connecting rod pair, 73 Driving cylinder 1, 74 Driving cylinder 2, 75 Angle limit

[0048] W spiral welded pipe, A conveying direction, T weld ridge DETAILED DESCRIPTION

[0049] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but are not intended to limit the scope of the present invention.

[0050] Example 1

[0051] A fly cutting device for large diameter thick wall spiral welded pipe, comprising

[0052] The synchronization mechanism 10 is provided below the continuously formed spiral welded pipe W and is used to abut the spiral welded pipe and remove its rotational component to replicate its axial movement component V. 轴 The synchronization mechanism 10 includes a synchronization trolley 11 and a pair of abutments 12, the abutment pair 12 is symmetrically arranged on both sides of the spiral welded pipe and can be selectively coupled to connect the spiral welded pipe W, the rotation and translation of the spiral welded pipe W is transmitted to the synchronization mechanism 10 without sliding to achieve synchronization;

[0053] A cutting device 20 is fixed to the synchronization mechanism 10 and includes a cutting torch 21 for cutting the spiral welded pipe when the spiral welded pipe rotates;

[0054] The tool setting mechanism 50 includes a detection module 51 and a tool setting module 52. The detection module 51 is arranged in front of the spiral welded pipe, and is used to detect the arrival of the end of the steel pipe and trigger synchronous following; the tool setting module 52 is connected to the cutting torch 21, and is used to accurately align the cutting point of the cutting torch 21 at a fixed length L0 from the end of the steel pipe.

[0055] The synchronization mechanism 10 includes a synchronization trolley 11, which is mounted on parallel tracks 13 via rollers. The abutment pair 12 comprises an elastic pressure belt 30 and a supporting chain belt 40. The elastic pressure belt 30 includes a concave roller frame 31, which is equipped with a top roller 32, a bottom roller 1 33, and a bottom roller 2 34. A circulating elastic belt 35 is rolled between the top roller 32, the bottom roller 2 34, and the bottom roller 1 33. The elastic belt 35 comprises a rubber drive layer and a thermoplastic elastomer layer, providing high elasticity and uniform power transmission.

[0056] The support chain 40 includes a top support roller 41, a bottom support roller 42, and a tension roller 44. The axes of the bottom support rollers 42 are located approximately to the left and right of the lowest position of a vertical cross-section of the spiral welded pipe passing through the central axis. The axes of the top support rollers are located approximately below a horizontal cross-section of the spiral welded pipe passing through the central axis. A circulating support chain 43 is provided between the top support rollers 41 and the bottom support rollers 42. The circulating support chain 43 connects the top support rollers 41, the tension roller 44, and the bottom support rollers 42. The top support rollers 41 and the bottom support rollers 42 are each moved between a pressing position and a retreated position by an opening and closing drive unit. The opening and closing drive part is a symmetrical drive 70, which includes an L-shaped rod pair 71 pivoted on the tension roller 44, and the bending part of the L-shaped rod pair 71 is pivotally connected to the tension roller 44; the long rod part of the L-shaped rod pair 71 is pivotally connected to the top support roller 41 and the bottom support roller 42, respectively, and the short rod part of the L-shaped rod pair 71 is pivotally connected to the equal-length connecting rod pair 72, and the other end of the equal-length connecting rod pair 72 is pivotally connected to the driving cylinder 1 73 and the driving cylinder 2 74. The up and down movement of the driving cylinder 1 73 and the driving cylinder 2 74 respectively drives the L-shaped rod pair 71 to rotate about the roller axis of the tension roller 44 through the equal-length connecting rod pair 72, thereby driving the top pressure roller 41 and the bottom support roller 42 to switch between the retracted position P2 and the pressing position P1. The pressing position is where the elastic pressure belt 30 contacts the outer circumference of the spiral welded pipe W, and the retracted position P2 is where the support chain belt 40 and the elastic pressure belt 30 are separated from the outer circumference of the spiral welded pipe W. In order to enable the equal-length connecting rod pair 72 to be pushed upward when the driving cylinders 1 and 2 are raised, an angle limiter 75 is fixedly provided at the pivotal connection between the equal-length connecting rod pair 72 and the output shaft of the driving cylinder.

[0057] The abutment pair 12 can be selectively coupled to connect the spiral welded pipe W to achieve the following: the two elastic pressure belts 30 are simultaneously pressed against the outer circumference of the spiral welded pipe W through the corresponding support chain belts 40. Specifically, the driving cylinder 1 73 rises, and due to the fixed rod length of the equal-length connecting rod pair 72, the L-shaped rod pair 71 that controls the top support roller 41 rotates counterclockwise around the roller axis of the tension roller 44, thereby driving the two top support rollers 41 to move from the retreat position to the pressing position; the driving cylinder 2 74 descends, and due to the fixed rod length of the equal-length connecting rod pair 72, the L-shaped rod pair 71 that controls the bottom support roller 42 rotates clockwise around the roller axis of the tension roller 44, thereby driving the two bottom support rollers 42 to move from the retreat position to the pressing position.

[0058] The driving cylinder 1 73 and the driving cylinder 2 74 are respectively connected to the same air pressure source. In the pressing position, the top support roller 41 and the bottom support roller 42 respectively apply the same and constant pressing force to the elastic pressing belt 30 and the outer peripheral surface of the steel pipe.

[0059] Preferably, two abutment pairs 12 are spaced apart and arranged side by side in the direction of the central axis of the spiral welded pipe, so that the abutment area can be increased.

[0060] The spiral welded pipe spirals forward relative to the spiral forming machine, meaning its weld ribs form a right-handed spiral. During rotation, the weld ribs cannot simultaneously enter both sides of the pipe. When a weld rib enters between the left elastic pressure band 30 and the spiral welded pipe W, subsequent weld ribs inevitably spiral downward from the top of the pipe through the left half. However, no weld ribs enter between the right elastic pressure band 30 and the spiral welded pipe W, which is directly opposite the right elastic pressure band 30 at the same axial position. This principle is utilized to ensure that even if a weld rib enters and causes a sudden axial slip between the elastic pressure band 30 and the spiral welded pipe W on one side, this tendency is offset by the static friction between the opposite elastic pressure band 34 and the spiral welded pipe W, preventing axial slip between the spiral welded pipe W and the abutment 12. The synchronization mechanism 10 ensures that, while the spiral welded pipe W undergoes both axial linear motion and circumferential rotational motion, the spiral welded pipe W only undergoes rotational motion relative to the cutting torch, thereby achieving a smooth cut end of the pipe. That is, after synchronization, when cutting the pipe, the cutting torch mechanism 21 does not move, and the welded pipe rotates one circle, that is, moves forward one pitch, and the welded pipe is just cut off.

[0061] The tool setting mechanism 50 includes a follow-up detection module 51, a tool setting module 52 and a track trolley 53. The follow-up detection module 51 is provided on the track trolley 53 and is used to detect whether the end of the steel pipe has arrived and synchronously follow the end of the steel pipe. The follow-up detection module 51 includes a head tracker 54 and a laser receiver 55. The track trolley 53 is vertically provided with a follower rod 56. The head tracker 54 and the laser receiver 55 are located in the same vertical plane and are fixed on the follower rod 56 at intervals. The track trolley 53 is driven by a driving source and can move along the guide rail with the same axial component V as the spiral welded pipe W. 轴 Tracking movement at the same speed and in the same direction. The driving source is preferably a rack and pinion pair, and the gear is connected to the servo motor, so that the follower rod 56 switches between the initial position and the follower position. The length measurement module is started, and the specific execution is as follows: ① Initialization, move the follower module 51 and the synchronization mechanism 10 to the initial position respectively; the initial position of the synchronization mechanism is located at a fixed position parallel to the track 13; the track trolley 53 of the follower module 51 is located at the rated length L from the tool setting module 52, for example, the rated length L of the steel pipe is 12000mm; ② Execute the fixed length detection cycle: the head tracker 54 following the length measurement detects whether the end of the steel pipe passes every certain time, and the interval time t 隔 Can be set; the cycle starts, detects whether the end of the steel pipe has passed? If the head tracker 54 detects that the end of the steel pipe has not reached the head tracker 54 position, then t 检 Timing starts when time t 检 =t 隔 When the head tracker 54 detects that the end of the steel pipe has reached the position of the head tracker 54, the cycle ends. ③ Execute pipe end following: The drive source starts, driving the follow-up module 51 to move along the guide rail with the same axial component V as the spiral welded pipe W. 轴The head tracker 54 is an infrared sensor or a camera.

[0062] The tool setting module 52 is installed on the cutting device 20 and is used to precisely align the cutting point of the cutting torch at a fixed length L0 from the end of the steel pipe. The tool setting module 52 includes a laser emitter 57 and a direct drive source 58. The laser emitter 57 and the cutting torch 25 of the cutting torch mechanism 21 are located in the same vertical plane and fixed to the synchronization rod 59 of the synchronization trolley 11 with an interval between them. The laser emitter 57 is aligned with the laser receiver 55 in a direction parallel to the central axis of the spiral welded pipe W. The bottom of the synchronization rod 59 is installed on the synchronization trolley 11 via a slider that slides along the slide rail. The slider is also connected to the drive source, which is preferably a screw-nut pair. The slider is fixedly connected to the nut, which is screwed onto the screw. The rotation of the screw drives the nut and slider along the slide rail and the synchronization rod 59. A gear rack pair can also be used. The tool setting module initiates tool setting, specifically as follows: ① Tool setting movement: The laser emitter 57 emits a laser beam, and the laser receiver 55 receives the laser beam, measuring the actual measured length L1 of the steel pipe. Based on the difference ΔL between the actual measured length L1 and the fixed length L0, the drive source drives the synchronization rod 59 and the laser emitter 57 and cutting torch 210 of the torch mechanism 21 on it to catch up to the fixed length L0, for example, L0 = 12020mm. ② Verify the fixed length: The laser emitter 57 emits a laser beam again, and the laser receiver 55 receives the laser beam again, measuring the actual measured length L1 of the steel pipe. A check is performed to see if L1 is equal to L0, for example, |L1-L0| ≤ δ, where δ can be set, for example, δ = 0.1mm. If it is equal, the process ends; if not, the tool setting process repeats step ①. If it is still not equal after two iterations, the process exits abnormally. If it is equal, the process ends, triggering the torch mechanism 21 to begin cutting.

[0063] The design of the above-mentioned tool setting mechanism 50 is mainly because the synchronization mechanism 10 requires a certain amount of time from triggering to synchronization completion. Although this time is relatively short, actual measurements have shown that during this time, the spiral welded pipe has moved forward 5-10mm, or due to unpredictable reasons, the spiral welded pipe has offset linearly relative to the synchronization mechanism, which causes the cutting torch 25 to start cutting directly, resulting in a large error. With the tool setting mechanism 50, the steel pipe length can keep the cutting torch within the 0mm-5mm tolerance range of the fixed length L0. For example, for a spiral welded pipe with a rated length L=12000mm, a 10mm machining allowance for the butt weld groove is reserved on both sides, and the cutting fixed length L0 is determined to be 12020mm. The tolerance range is 0~+5mm, which is expressed as 12020 5 The reason for the 5mm error is that the end cutting line of the arc curve cut by the cutting torch is fitted by a series of multi-points, and there needs to be at least 3mm of grinding allowance on the end plane.

[0064] A length control method for an automatic fly-cutting device for large-diameter thick-wall spiral welded pipes comprises the following steps:

[0065] S0 fixed length detection

[0066] The head tracker 54 detects whether the steel pipe end passes through the fixed length detection cycle at a fixed time. The cycle time is t 隔 Can be set; the cycle starts, detects whether the end of the steel pipe has passed? If the head tracker 54 detects that the end of the steel pipe has not reached the head tracker 54 position, the timing time t 检 =0, timing starts, when t 检 =t 隔 After that, the loop returns to the beginning; if the head tracker 54 detects that the end of the steel pipe reaches the head tracker 54, the loop ends and S1 is executed;

[0067] S1 triggers tracking and synchronization simultaneously

[0068] The detection module 51 is initialized, the driving source is started, and the detection module 51 is driven to move along the guide rail with the same axial movement component V as the spiral welded pipe W. 轴 At the same speed and in the same direction, the tracking moves forward; at the same time, the abutment pair 12 of the synchronization mechanism 20 starts coupling and connecting the spiral welded pipe W;

[0069] Axial movement component V 轴 It is calculated, for example, if the forming angle α of the spiral welded pipe and the forward speed V of the steel pipe are known 轴 Plate delivery machine speed V 板 , delivery machine speed V 板 It is obtained by measuring the automatic speed of the encoder board, and the following formula is used

[0070]

[0071] So we get v 轴 =cosα·v 板 (2).

[0072] Of course, the axial movement component V 轴 It can also be measured by the distance traveled per unit time.

[0073] S2 fixed length tool setting

[0074] The tool setting module 52 starts tool setting, and moves the cutting torch 21 to the fixed length L0 according to the difference ⊿L between the actual measured length L1 and the fixed length L0; specifically: the number of repetitions i=0, ① tool setting movement: the laser emission 57 emits a laser beam, the laser reception 55 receives the laser beam, and measures the actual measured length L1 of the steel pipe. According to the difference ⊿L between the actual measured length L1 and the fixed length L0, the direct drive source 58 can drive the cutting torch 21 to catch up and move to the fixed length L0; ② verify the fixed length, the laser emission 54 emits the laser beam again, the laser reception 55 receives the laser beam again, measures the actual measured length L1 of the steel pipe, and checks whether L1 is equal to L0; if equal and i≤10, then end; if not equal, then i=i+1, i≤10 and execute step ①.

[0075] S3 cutting

[0076] The cutting torch 210 of the cutting torch mechanism 21 ignites and cuts until the entire circumference of the steel pipe is cut off.

[0077] Example 2

[0078] The supporting chain belt 40 and the measuring module are improved, a tensioning roller is omitted, and the structure is simplified. The other structures are the same as those in Example 1, and only the different structures are described here.

[0079] An automatic fly cutting device for large diameter thick wall spiral welded pipes, comprising

[0080] The support chain 400 includes a bottom support roller 402 and a circulating support chain 403. The support chain 403 is disposed between the bottom support roller 402 and the top roller 32. The circulating elastic belt 35 is rollably disposed between the top roller 32, the second bottom roller 34, and the first bottom roller 33. The support chain 403 is superimposed on one side of the elastic belt 35. The concave roller frame 31 is disposed on the crossbeam frame 401 at its upper portion and is tilted on the bottom oblique frame 404 at its lower portion. The top roller 32 is slidably mounted on the crossbeam frame 401 via a slider. The bottom support pressure roller 402 is pivotally mounted on the second bottom roller 34 via an L-shaped rod pair 71. The top roller 32 and the bottom support pressure roller 402 are switched between a pressing position and a retreated position via an opening and closing drive unit.

[0081] The opening and closing drive unit is a symmetrical drive 60, which includes a screw-nut pair 61 and a variable-axis driven shaft 62. The screw of the screw-nut pair 61 includes a forward and reverse threaded screw 63 and a mid-segment screw 64, which is disposed between the forward and reverse threaded screws 63. The two nuts are screw-fitted onto the forward and reverse threaded screws 63. The variable-axis driven shaft 62 is connected to the mid-segment screw 64, converting the rotation of the mid-segment screw 64 into movement of a vertical displacement shaft 65 in a vertical direction perpendicular to the screw axis. The symmetrical drive 60 drives and connects the two bottom support rollers 402 and the two top rollers 32 as follows: the two nuts of the screw-nut pair 61 are respectively fixedly connected to the sliders of the two top rollers 32, and the positive and negative threaded screws 63 of the screw-nut pair 61 are fixedly installed on the bottom plate of the synchronous trolley 11 and driven by the drive motor. The bottom support rollers 402 are driven and connected to the variable axis driven 62 by the symmetrical drive 1 70 pivotally connected to the bottom roller 2 34. Specifically, the corners of the two L-shaped rod pairs 71 are pivotally connected to the bottom roller 2 34, the ends of the short rod portions of the L-shaped rod pairs 71 are pivotally connected to the rotating shafts of the bottom support rollers 402, and the ends of the long rod portions of the L-shaped rod pairs 71 are pivotally connected to the equal-length connecting rod pairs 72. The other ends of the equal-length connecting rod pairs 72 are simultaneously pivotally connected to the top of the vertical movement shaft 65. The rotation of the screw middle section 64 is converted into the up and down movement of the vertical movement shaft 65, thereby driving the bottom support rollers 402 to switch between the pressing position and the retreated position through the symmetrical drive 1 70. The specific operation is as follows: the driving motor rotates to drive the screw, and the positive and negative threaded screws 63 drive the two nuts and the top roller 32 to approach or move away from each other along the screw axis. The closest position is the pressing position of the top roller 32, and the farthest position is the retreat position of the top roller 32. The two positions are direct movement switching; at the same time, the variable axis driven 62 uses the rotation of the screw middle section 64 as input, and the output is the up and down movement of the vertical shift shaft 65, and then drives the bottom support roller 402 to rotate and switch between the pressing position and the retreat position through the symmetrical drive 70. Figure 7 As shown, the variable-shaft driven member 62 uses the screw midsection 64 as its rotational input, driving the worm gear 66 and nut 67. The rotation of nut 67 drives the vertical displacement shaft 65 up and down. In a worm gear transmission mechanism, when the transmission ratio is relatively large, the worm is used as the active element, driving the worm gear. When the worm's lead angle is less than the equivalent friction angle between the meshing gear teeth, reverse self-locking is achieved, meaning that only the worm gear drives the worm, not the other way around. Utilizing this self-locking property, abutment clamping force is maintained for a long time without loosening.

[0082] The design of the symmetrical drive 60 enables symmetrical movement of the opening and closing drive components of the abutment pair 12, ensuring that the abutment pair 12 simultaneously abuts the outer circumference of the spiral welded pipe on both sides, thereby reducing flatness errors during cutting. Furthermore, compared to Example 1, while omitting a tensioning roller, a drive source is also omitted. A single rotary motor is used to simultaneously drive the bottom support roller 402 and the top roller 32 to switch between the pressing and retreating positions, achieving cost reductions through a simple structure.

[0083] A length control method for an automatic fly-cutting device for large-diameter thick-walled spiral welded pipes, further comprising the following steps:

[0084] Also included between step S1 and step S2

[0085] Step S11: Alignment and Calibration

[0086] The head tracker 54 is a camera mounted roughly flush with the horizontal axis of the spiral welded pipe. It measures the longest endpoint A and shortest endpoint B of the pipe edge near the head tracker 54 during one rotation. The axial distance ΔB between the laser receiver 55 and the lowest endpoint B is calculated, and the driving source drives the tracking module 51 to align the laser receiver 55 with the shortest endpoint B.

[0087] Step S11 is required because large-diameter, thick-walled spiral welded pipes that have not been face-milled can have errors in the perpendicularity between the cutting plane and the central axis during cutting. This means they are prone to being cut at an angle, an inclination that is invisible to the naked eye. Alignment calibration aligns the laser receiver 55 to the shortest endpoint B to minimize the length error caused by this angled cutting.

[0088] Principle Description

[0089] To solve any of the following technical problems: 1. Precise pipe length; 2. Control the coincidence of the starting and ending points of the cutting seam, with the cutting surface perpendicular to the axis of the welded pipe and the perpendicularity between the end face of the cut and the axis of the welded pipe controlled within 1mm; 3. Miniaturization of the cutting device, the following innovative ideas were adopted:

[0090] (1) Synchronization and tool setting are separated to achieve miniaturization of the cutting device.

[0091] In the prior art, the synchronization mechanism 20 usually integrates dynamic tracking and sizing functions at the same time, which makes the synchronization mechanism structure complex and heavy, making it easy to deviate and difficult to ensure accuracy. In this application, the synchronization mechanism is separated from the tool setting mechanism. The synchronization mechanism 10 is only responsible for synchronization. Its specific function is to offset the rotation component of the steel pipe and only synchronize the linear component V of the axial forward movement of the spiral welded pipe along the central axis. 轴 The spiral welded pipe W only rotates relative to the cutting torch, resulting in a smooth cut. The tool setting mechanism consists of a forward-facing, continuous-measurement module and a rear-facing, fixed-length tool setting mechanism. The forward-facing, continuous-measurement module initiates both tracking and fixed-length tool setting upon arrival of the pipe end. The fixed-length tool setting mechanism, located on the synchronization mechanism, is responsible for positioning the cutting torch to the fixed length L0. Separating the tool setting mechanism 50 from the synchronization mechanism 10 and separating the forward-measurement module 51 from the synchronization mechanism 10 results in a more compact cutting device and easier precision assurance.

[0092] (2) The abutment is set axially symmetrically, and the elastic pressure belt is in contact with the surface, which is not easy to deviate; the elastic pressure belt and support chain belt are used to avoid indentation.

[0093] The synchronization mechanism 10 symmetrically sets a pair of abutments 12 on both sides of the spiral welded pipe W along the central axis. When the spiral welded pipe rotates and moves forward, the weld ridge T of the spiral welded pipe cannot enter between the abutments and the spiral welded pipe on both sides at the same time. Even if one side has a tendency to axially deviate due to the beating of the ridge, the abutment on the other side can still maintain it. Combined with the elastic pressure belt 30, the surface contact with elastic pressure force along the outer surface of the steel pipe changes the point contact of the rigid roller abutment in the prior art, so it can ensure that the spiral welded pipe will not produce axial deviation. At the same time, the abutment pair 12 uses the elastic pressure belt 30 to press the support chain belt 40 on the outside, so that the elastic pressure belt 30 is set between the spiral welded pipe and the support chain belt 40, ensuring that no indentation will appear under the premise of ensuring the clamping force, thus overcoming the contradiction between avoiding indentation and ensuring the clamping force.

[0094] (3) The synchronous mechanism of the abutment is symmetrically arranged to adapt to the change of the steel pipe diameter.

[0095] The symmetrically arranged abutments can accommodate spiral welded pipes within a certain diameter range. During synchronous abutment, the larger the pipe diameter, the lower the abutment position of the supporting roller 41 will be. If the abutment position falls below the 45-degree line, a larger synchronous mechanism can be replaced, significantly saving time. Compared to existing synchronous mechanisms, this is more adaptable to changes in pipe diameter.

[0096] (4) After synchronization, the measuring module is combined with the tool setting module to realize real-time measurement with high precision.

[0097] When the head tracker 54 detects that the end of the steel pipe has arrived, the tracking module 51 immediately starts to follow at the same speed, so that the laser receiver 55 remains flush with the end of the steel pipe. At the same time, the tool setting module 52 on the synchronous carriage 11 is started, and the actual length L1 is measured by the laser emission 57 and the laser receiver 55, and compared with the fixed length L0, and ⊿L is calculated. Then the driving source drives the laser emission 57 and the cutting torch 22 to move to the fixed length L0, and then the cutting torch 22 starts to ignite and cut. The point that the cutting torch 22 is aligned with is the actual measured point by the laser emission 57 and the laser receiver 55 of the previous tracking module 51, which is the measured length. When the tool setting module 52 is working, at this moment, the synchronization mechanism 10 has completed the synchronization action in step S1, avoiding the large fixed length error caused by the need to give an estimated margin due to the synchronous clamping time in the existing technology.

[0098] (5) The screw-nut pair 61 cooperates with the variable-axis driven 62, and only one driving source is used to achieve symmetrical drive.

[0099] The screw-nut pair 61 switches the two top rollers 32 between the retracted and abutted positions. Simultaneously, the variable-axis driven device 62 uses the spiral midsection 64 of the screw-nut pair 61 as input and the vertical movement of the vertical axis 65, which is perpendicular to the screw, as output. This in turn drives the symmetrical drive 70 to switch the bottom support roller 402 between the retracted and abutted positions. This single motor drive, which only drives the screw, eliminates a cylinder or motor, significantly reducing the manufacturing cost of the spiral welded pipe flycutting device over the long term.

[0100] An automatic fly-cutting device for large-diameter thick-walled spiral welded pipes and a sizing control method thereof are disclosed. Abutments are arranged axially symmetrically, and an elastic pressure belt 30 cooperates with a support chain belt 40 to abut the outer circumference of the steel pipe, making it difficult for the axis to deviate. After synchronization, a measuring module 51 of the sizing mechanism 50 cooperates with a tool setting module 52 to achieve actual sizing, resulting in high sizing accuracy and great practical value.

Claims

1. An automatic fly-cutting device for large-diameter thick-walled spiral welded pipes, characterized in that: include The synchronization mechanism (10) is arranged below the continuously formed spiral welded pipe (W) and is used to abut against the spiral welded pipe and remove its rotational component to replicate its axial movement component V 轴 The synchronization mechanism (10) includes a synchronization trolley (11) and a pair of abutments (12). The pair of abutments (12) are symmetrically arranged on both sides of the spiral welded pipe and can be selectively coupled to the spiral welded pipe (W) to transmit the linear movement of the spiral welded pipe (W) to the synchronization trolley (10) without sliding to achieve synchronization. A cutting device (20), the cutting device (20) is fixedly mounted on the synchronization mechanism (10), the cutting device (20) comprises a cutting torch (21) and is used for cutting the spiral welded pipe when the spiral welded pipe rotates; A tool setting mechanism (50), the tool setting mechanism (50) comprising a follow-up detection module (51) and a tool setting module (52), the follow-up detection module (51) being arranged in front of the spiral welded pipe and used for detecting the arrival of the end of the steel pipe and triggering synchronous following; The knife alignment module (52) is arranged on the cutting device (20) and is used to accurately align the cutting point of the cutting torch (21) at a fixed length L0 from the end of the steel pipe.

2. The automatic fly-cutting device for large-diameter thick-walled spiral welded pipe according to claim 1, characterized in that: The abutment pair (12) comprises an elastic pressing belt (30) and a supporting chain belt (40, 400), wherein the supporting chain belt (40) is arranged outside the elastic pressing belt (30); the elastic pressing belt (30) comprises a concave roller frame (31), wherein the concave roller frame (31) is provided with a top roller (32), a bottom roller 1 (33), and a bottom roller 2 (34), and a circulating elastic belt (35) is rollingly arranged between the top roller (32), the bottom roller 2 (34), and the bottom roller 1 (33).

3. The automatic fly-cutting device for large-diameter thick-walled spiral welded pipe according to claim 2, characterized in that: The support chain belt (40) comprises a top support pressure roller (41), a bottom support pressure roller (42) and a tension roller (44); a circulating support chain belt (43) is connected between the top support pressure roller (41), the tension roller (44) and the bottom support roller (42); an L-shaped rod 1 (45) is rotatably provided between the top support pressure roller (41) and the tension roller (44); an L-shaped rod 2 (46) is provided between the bottom support roller (42) and the tension roller (44); the L-shaped rod 1 (45) and the L-shaped rod 2 (46) are driven by a driving source to switch the top support pressure roller (41) and the bottom support pressure roller (42) between a retreat position and a pressing position; the pressing position is a position where the support chain belt is pressed against the outer peripheral surface of the spiral welded pipe through an elastic pressing belt; the retreat position is a position where the support chain belt 40 and the elastic pressing belt leave the outer peripheral surface of the spiral welded pipe.

4. The automatic fly-cutting device for large-diameter thick-walled spiral welded pipe according to any one of claims 1 to 3, characterized in that: The abutment pair (12) can be selectively coupled to connect the spiral welded pipe W and is implemented as follows: two elastic pressure belts (30) are pressed against the outer circumference of the spiral welded pipe W through corresponding supporting chains (40) at the same time. Specifically, the driving source drives the top supporting roller (41) and the bottom supporting roller (42) to move from the retreated position to the pressing position. In the pressing position, the top supporting roller (41) and the bottom supporting roller (42) respectively apply the same and constant pressing force to the outer circumference of the spiral welded pipe through the elastic pressure belts (30).

5. An automatic fly-cutting device for large-diameter thick-walled spiral welded pipes as claimed in claim 1, characterized in that: The tool setting mechanism (50) further comprises a track trolley (53), a follow-up detection module (51) is arranged on the track trolley (53), and is used to detect whether the end of the steel pipe has arrived and synchronously follow the end of the steel pipe. The follow-up detection module (51) comprises a head tracker (54) and a laser receiver (55). The track trolley (53) is provided with a follower rod (56) perpendicular to the central axis of the spiral welded pipe. The head tracker (54) and the laser receiver (55) are located in the same vertical plane and fixedly arranged on the follower rod (56) at intervals up and down. The track trolley (53) is driven by a driving source and can move along the guide rail with the same axial movement component V as the spiral welded pipe W. 轴 Tracking movement at the same speed and in the same direction.

6. The automatic fly-cutting device for large-diameter thick-walled spiral welded pipe according to claim 5, characterized in that: The tool setting module (52) is arranged on the cutting device (20), and the tool setting module (52) includes a laser emitter (57) and a driving source (58). The laser emitter (57) and the cutting torch (21) are located in the same vertical plane and fixed on a synchronization rod (59) of a synchronization trolley (11) with an interval between the upper and lower parts. The laser emitter (57) is aligned with the laser receiver (55) along a direction parallel to the central axis of the spiral welded pipe W; the bottom of the synchronization rod (59) is arranged on the synchronization trolley (11) by sliding along a slide rail through a slider, and the slider is connected to the driving source.

7. The automatic fly-cutting device for large-diameter thick-walled spiral welded pipe according to claim 5, characterized in that: The supporting chain belt (400) comprises a bottom supporting roller (402) and a circulating supporting chain belt (403), wherein the supporting chain belt (403) is rollingly arranged between the bottom supporting roller (402) and the top roller wheel (32), and the supporting chain belt (403) The concave roller frame (31) is stacked on the inner side of the elastic belt (35); the upper part of the concave roller frame (31) is arranged on the crossbeam frame (31.1), and the bottom part is inclined on the bottom inclined frame (31.2); the top roller (32) is slidably arranged on the crossbeam frame (31.1), and the bottom support and pressure roller (402) is slidably arranged on the bottom inclined frame (31.2); the top roller (32) and the bottom support and pressure roller (402) are respectively connected to a driving source.

8. A method for controlling the length of an automatic fly-cutting device for a large-diameter thick-walled spiral welded pipe according to any one of claims 1 to 7, characterized in that: The steps include: S0 Length Inspection The head tracker (54) detects whether the end of the steel pipe has passed through the fixed length detection cycle at a fixed time. The cycle time t 隔 Can be set; the cycle starts, detects whether the end of the steel pipe has passed? If the head tracker 54 detects that the end of the steel pipe has not reached the position of the head tracker 54, the timing time t 检 =0, timing starts, when t 检 =t 隔 After that, the loop returns to the beginning; if the head tracker 54 detects that the end of the steel pipe reaches the head tracker 54, the loop ends and S1 is executed; S1 triggers tracking and synchronization simultaneously The detection module (51) is initialized, the driving source is started, and the detection module (51) is driven along the guide rail with the same axial movement component V as the spiral welded pipe W. 轴 The device moves forward in the same direction and at the same speed; at the same time, the abutment pair 12 of the synchronization mechanism (20) starts coupling and connecting the spiral welded pipe W; S2 fixed length tool setting The tool setting module 52 starts tool setting, and moves the cutting torch 21 to the fixed length L0 according to the difference ⊿L between the actual measured length L1 and the fixed length L0; S3 Cutting The cutting torch (21) of the cutting device (20) is ignited and cut until the entire circumference of the steel pipe is cut off.

9. The automatic fly-cutting device for large-diameter thick-walled spiral welded pipe according to claim 8, characterized in that: Step S2 is specifically as follows: the number of repetitions i=0, ① tool setting movement: the laser emission (57) emits a laser beam, the laser reception (55) receives the laser beam, and the actual measured length L1 of the steel pipe is measured. According to the difference ⊿L between the actual measured length L1 and the fixed length L0, the driving source can drive the cutting torch (21) to catch up and move to the fixed length L0; ② verify the fixed length, the laser emission (57) emits a laser beam again, the laser reception (55) receives the laser beam again, and the actual measured length L1 of the steel pipe is measured, and whether L1 is equal to L0; if equal and i≤10, then end; if not equal, then i=i+1, and execute step ①.

10. The automatic fly-cutting device for large-diameter thick-walled spiral welded pipe according to claim 9, characterized in that: Also included between step S1 and step S2 Step S11: Alignment and calibration The head tracker (54) is a camera, which is installed horizontally and flushly along the center axis of the spiral welded pipe. It can measure the longest endpoint A and the shortest endpoint B of the edge of the steel pipe close to the head tracker after one rotation; calculate the axial distance ⊿B between the laser receiver (55) and the lowest endpoint B, and the driving source drives the measuring module (51) to align the laser receiver (55) to the shortest endpoint B.

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