Device and method for spiral welded pipe cutting and automatic advancing and retreating of pipe cutting trolley

Abstract

The invention provides a device and method for spiral welded pipe cutting and automatic advancing and retreating of a pipe cutting trolley, and belongs to the technical field of spiral welded pipe manufacturing, the device comprises the pipe cutting trolley and a hoisting mechanism, and the pipe cutting trolley is installed on a linear guide rail; a cutter wheel and a plasma cutting gun are arranged on the pipe cutting trolley, the hoisting mechanism is installed at the end of the linear guide rail and used for driving the pipe cutting trolley to reciprocate, the hoisting mechanism comprises a steel wire rope, a hoisting wheel and a one-way bearing, the hoisting wheel is connected with the speed reducer through a transmission shaft, and the one-way bearing is arranged between the hoisting wheel and the transmission shaft. The one-way bearing comprises a clamping key, a bearing inner ring and a bearing outer ring. According to the overall structure and speed matching of the inner ring and the outer ring of the bearing during operation, the pipe cutting trolley can depend on a cutter wheel power source during forward movement and depend on a motor as a power source during backward movement, the objective requirement that different power sources are needed in the movement process in different directions is met, the labor intensity of workers is reduced, and the working efficiency is improved. And the reliability and the stability are ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of spiral welded pipe manufacturing, and in particular relates to a device and method for cutting spiral welded pipes and automatically advancing and retreating a pipe cutting trolley. Background Art

[0002] With the development of economy and the growth of population, the demand for infrastructure construction is increasing, which has promoted the growth of spiral welded pipe market. As an important conveying pipe, spiral welded pipe plays an important role in the construction of infrastructure such as roads, bridges, water supply and drainage. Its production is of great significance, which is mainly reflected in the following aspects: (1) Urban heating field: In the urban centralized heating system, spiral welded pipe can effectively convey heat energy, provide a stable heat source for residents and industrial users, and improve the quality of life of urban residents and the efficiency of industrial production; (2) Water conservancy engineering: Spiral welded pipe is used in the water pipeline of urban water supply system, which can ensure the safety and stability of water supply, improve the quality and efficiency of water supply system, and provide high-quality water supply services for the people; (3) Industrial production: It is used to convey various chemical raw materials and products. Its corrosion resistance can adapt to the characteristics of chemical media and ensure the normal progress of chemical production; (4) Building structure field: In bridge construction, spiral welded pipe can be used as a supporting structure or part of the pier of the bridge, bearing the dead weight and traffic load of the bridge, and ensuring the safety and durability of the bridge.

[0003] In the production process of spiral welded pipes, pipe cutting is an important part. At present, the domestic cutting and subsequent processing of spiral welded pipes are mainly completed by manually operated equipment. Figure 1As shown, the existing spiral welded pipe 104 is transported forward while rotating during production, and there are two movements, rotation and forward movement. In order to realize the cutting of the existing spiral welded pipe 104 at the specified position, it is mainly realized by using the existing plasma cutting gun 103 placed on the existing pipe cutting trolley 101 to make a circumferential rotation relative to the existing spiral welded pipe 104. The existing pipe cutting trolley 101 is placed on a horizontally laid guide rail 105, and makes a forward or backward reciprocating linear motion along the guide rail 105, and the existing spiral welded pipe 104 is cut by the existing plasma cutting gun 103 installed on the existing pipe cutting trolley 101. In order to realize the specified length cutting of the existing spiral welded pipe 104, a length detection sensor 106 is generally installed at the production end of the existing spiral welded pipe 104. When the length detection sensor 106 senses that the existing spiral welded pipe 104 has reached this position, it will send a signal to the control device. At this time, the cutter wheel device 102 on the existing pipe cutting trolley 101 will extend and closely contact the existing spiral welded pipe 104. The existing spiral welded pipe 104 transmits the movement to the existing pipe cutting trolley 101 through friction. At this time, the existing pipe cutting trolley 101 will move forward synchronously with the existing spiral welded pipe 104 in the horizontal direction. At the same time, the existing plasma cutting gun 103 performs a circular motion relative to the existing spiral welded pipe 104. The worker manually controls the existing plasma cutting gun 103 to start cutting. After cutting a circle, the existing plasma cutting gun 103 is manually closed to complete the cutting of the existing spiral welded pipe 104. After the cutting of the existing spiral welded pipe 104 is completed, the worker manually pushes the existing pipe cutting trolley 101 back to the initial position.

[0004] It can be seen that the current domestic spiral welded pipe related manufacturing enterprises are still in the stage of manual operation. During the production process of the existing spiral welded pipe, due to factors such as inconsistent adjustment of the position of the welded pipe support wheel, the distance between the existing plasma cutting gun 103 and the existing spiral welded pipe 104 will change at any time. When the distance between the two is too close, the existing plasma cutting gun 103 may have a gun collision accident; and when the distance is too far, the existing plasma cutting gun 103 has the risk of plasma arc extinguishing. Therefore, during the production process of the existing spiral welded pipe 104, workers are required to always observe the distance between the existing plasma cutting gun 103 and the existing spiral welded pipe 104, so that when the distance is not appropriate, it can be adjusted in time to ensure the stable production of the cutting operation. In addition, due to the sparks of the existing spiral welded pipe 104 cutting operation, a lot of smoke pollution is generated, making the working site environment relatively harsh. In the long run, the physical and mental health of the workers at this station is easily damaged. Moreover, after the cutting of the existing spiral welded pipe 104 is completed, the workers need to manually push the existing pipe cutting trolley 101 back each time, and the required thrust is relatively large, and the labor intensity of the workers is also high.

[0005] If a traditional winch is used, the existing pipe cutting trolley can move forward and backward. By controlling the winch wheel to rotate forward and reverse, the wire rope is driven to wind or loosen on the winch wheel. The two ends of the wire rope and the front and rear ends of the trolley are connected together through fixed pulleys to form a whole. However, the traditional winch cannot meet the needs of spiral welded pipe cutting operations. When the spiral welded pipe is operated, the existing winch cannot adapt to different external drive inputs when the existing pipe cutting trolley moves forward and backward. Specifically, when the existing pipe cutting trolley moves forward, the knife wheel device on the existing pipe cutting trolley will rise under the drive of the cylinder and roll in close contact with the existing spiral welded pipe. The existing spiral welded pipe will transmit its own forward motion to the existing pipe cutting trolley through the knife wheel device, and the existing pipe cutting trolley will achieve synchronization with the existing spiral welded pipe in the horizontal direction. The forward motion of the existing pipe cutting trolley will drive the wire rope to rotate forward along the winch wheel. The internal transmission of the winch is mainly a reducer and an electric motor, and the types of reducers are mostly gear reducers and worm reducers. The wire rope drives the winch wheel to rotate forward, and the motion is directly transmitted to the asynchronous motor through the wire rope via the reducer main shaft. When the gear reducer is used, the wire rope will be subject to very large friction resistance, which will affect the consistency of the movement position of the existing pipe cutting trolley and the existing spiral welded pipe in the forward direction. The position deviation will be caused by sliding friction, which will destroy the cutting of the horizontal end face of the existing spiral welded pipe by the plasma cutting gun, resulting in an unqualified elliptical cutting surface. When the worm gear is used for deceleration, due to its unidirectional motion transmission, the worm can only input the turbine output, and the motion cannot be transmitted from the output to the input. Therefore, the wire rope will be directly broken or sliding friction will occur between the cutter wheel and the existing spiral welded pipe, making the existing pipe cutting trolley unable to move.

[0006] The existing pipe cutting trolley can also move forward and backward through the gear rack mechanism. The structure is that the motor drives the gear to rotate through the reducer. The gear mechanism is installed on the body of the existing pipe cutting trolley, and the rack is placed next to the trolley track. The meshing movement of the gear rack drives the trolley to move forward and backward. However, this mechanism also cannot meet the needs of existing spiral welded pipe cutting operations. The power source of the existing pipe cutting trolley is basically the cutter wheel device, and the power demand cannot be provided by the motor, otherwise it will affect and damage the plasma cutting gun relative to the horizontal end face cutting of the existing spiral welded pipe, resulting in unqualified sections such as ellipses.

[0007] In addition, the rodless cylinder solution can also realize the forward and backward movement of the pipe cutting trolley, but this solution will greatly increase the cost of the rodless cylinder when the pipe cutting trolley has a large stroke. In addition, the cutting operation environment is dusty and the cylinder life will be greatly reduced. In addition, when working in the cold winter season, it is easy to cause freezing failures due to the weather. Summary of the invention

[0008] The problem to be solved by the present invention is to provide a device and method for cutting spiral welded pipes and automatically advancing and retreating a pipe cutting trolley.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is: a device for spiral welded pipe cutting and automatic advance and retreat of the pipe cutting trolley, comprising a pipe cutting trolley, a cutter wheel, a plasma cutting gun and a hoisting mechanism, wherein the pipe cutting trolley is installed on a linear guide rail; a cutter wheel mounting frame and a cutting gun mounting column are provided on the pipe cutting trolley, the cutter wheel is installed on the cutter wheel mounting frame through a lifting mechanism, the plasma cutting gun is installed on the cutting gun mounting column through a linear module mechanism, the hoisting mechanism is installed at the end position of the linear guide rail, the hoisting mechanism is used to drive the pipe cutting trolley to reciprocate, the hoisting mechanism comprises a wire rope, a hoisting wheel and a one-way bearing, after the two ends of the wire rope pass around the hoisting wheel, one end of the wire rope is connected to the pipe cutting trolley The front end is connected, and the other end bypasses the winch wheel and is connected to the rear end of the pipe cutting trolley through a fixed pulley fixed at the rear. The winch wheel is connected to the reducer and the motor through a transmission shaft; a one-way bearing is arranged between the winch wheel and the transmission shaft, and the one-way bearing comprises a key, a bearing inner ring and a bearing outer ring. The bearing outer ring is connected to the winch wheel, and the bearing inner ring is connected to the transmission shaft. A number of freely movable keys are evenly arranged between the bearing inner ring and the bearing outer ring, and a number of one-way limiting protrusions are evenly arranged on the outer wall of the bearing inner ring. The number of the one-way limiting protrusions is consistent with the number of the keys. A wedge-shaped limiting cavity is formed between the inner wall of the bearing outer ring, the outer wall of the bearing inner ring and the one-way limiting protrusion, and the key is correspondingly located in the wedge-shaped limiting cavity.

[0010] Furthermore, a laser displacement sensor is also provided on the cutting gun mounting column.

[0011] Furthermore, a narrow-band filter of 650-680 nm is installed inside the laser displacement sensor.

[0012] Furthermore, the linear module mechanism, laser displacement sensor and motor are all connected to a PLC controller.

[0013] Furthermore, the motor is a three-phase asynchronous motor; and the reducer is a worm gear reducer.

[0014] The present invention also provides a method for spiral welded pipe cutting and automatic advance and retreat of a pipe cutting trolley, comprising the following steps: S1. Driving the pipe cutting trolley forward with dual power sources: After the cutter wheel on the pipe cutting trolley is lifted and in close contact with the spiral welded pipe, the spiral welded pipe drives the pipe cutting trolley to move forward synchronously through rolling friction. When the pipe cutting trolley moves forward, the steel wire rope will provide a pulling force to the hoisting wheel, driving the outer ring of the bearing of the hoisting wheel of the hoisting mechanism to rotate forward, and the rotational speed of the outer ring of the bearing under the action of external force is V1; at the same time, the inner ring of the bearing is driven to rotate forward by the motor with a rotational speed of V2. The outer ring and the inner ring of the bearing rotate in the same direction, and when V1 < V2, the outer ring of the bearing rotates forward, and the pipe cutting trolley moves forward to realize the plasma circumferential cutting of the spiral welded pipe; S2. Cutting the spiral welded pipe: When the plasma cutting torch cuts the spiral welded pipe, due to the radial swing of the spiral welded pipe, the distance between the plasma cutting torch and the welded pipe changes. The linear module mechanism drives the plasma cutting torch to move forward or backward. The distance between the plasma cutting torch and the spiral welded pipe is measured non-contact by the laser displacement sensor and the distance information is transmitted to the PLC controller. After being processed by the PLC controller, the linear module mechanism is controlled to act, and the linear module mechanism adjusts the position of the plasma cutting torch in real time to ensure that the relative distance between the plasma cutting torch and the spiral welded pipe remains constant during the pipe cutting process, so as to ensure the normal operation of the spiral welded pipe cutting operation; S3. Driving the pipe cutting trolley backward with a single power source: After the spiral welded pipe is cut off, the cutter wheel in close contact with the spiral welded pipe drops and disengages. The motor drives the inner ring of the bearing to rotate reversely, and the key in the one-way bearing moves towards the space where the wedge-shaped limiting cavity becomes narrower, so that the relative rotational speed of the outer ring and the inner ring of the bearing decreases. Until the key is stuck, the outer ring and the inner ring of the bearing are relatively stationary and become a whole, and the outer ring of the bearing rotates reversely, driving the pipe cutting trolley back to the initial position through the steel wire rope.

[0015] Due to the adoption of the above technical solutions, the present invention has the following beneficial effects: The present invention has a simple structure and low cost, and realizes the automatic forward and backward movement of the pipe cutting trolley under different power source conditions. The present invention installs a one-way bearing between the transmission shaft and the winch wheel inside the winch mechanism, the outer ring of the bearing cooperates with the winch wheel, and the inner ring of the bearing cooperates with the output shaft of the reducer. When the pipe cutting trolley moves forward, the motor drives the inner ring of the bearing to rotate forward. If the speed V1 of the outer ring of the bearing is lower than the speed V2 of the inner ring of the bearing, the winch wheel matched with the outer ring of the bearing can rotate forward in the same direction under the power provided by the cutter wheel in contact with the spiral welded pipe, pulling the pipe cutting trolley forward. When the pipe cutting trolley moves backward, the cutter wheel in contact with the spiral welded pipe on the pipe cutting trolley has fallen, and the trolley is not controlled externally. It only needs to send instructions to the motor through the PLC controller, and the motor drives the inner ring of the bearing to rotate in the opposite direction. The movement of the inner ring of the bearing will drive the outer ring of the bearing and the winch wheel to reverse together, and pull the pipe cutting trolley back to the initial position. Therefore, the overall structure of the present invention and the speed coordination of the inner and outer rings of the bearing during operation can realize the objective demand of relying on the power source of the cutter wheel when moving forward and relying on the motor as the power source when moving backward, and different power sources are required during movement in different directions. It can be seen that the present invention no longer requires workers to push the trolley laboriously, reduces the labor intensity of workers, and ensures reliability and stability.

[0016] At the same time, the present invention can ensure that the relative distance between the plasma cutting gun and the spiral welded pipe remains unchanged during the pipe cutting process through a linear module mechanism and a laser displacement sensor equipped with a narrow-band filter, which not only improves the cutting quality, but also significantly increases the service life of the plasma cutting gun, and greatly reduces the labor intensity of the operators, thereby ensuring the physical and mental health of the operators. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be described in detail below with reference to the accompanying drawings and in combination with examples, and the advantages and implementation methods of the present invention will become more obvious. The contents shown in the accompanying drawings are only used to explain the present invention and do not constitute any limitation to the present invention in any sense. In the accompanying drawings: Figure 1 It is a schematic diagram of an existing spiral welded pipe cutting device in the prior art.

[0018] Figure 2 It is a structural schematic diagram of the present invention.

[0019] Figure 3 It is a side view of the present invention.

[0020] Figure 4 It is a structural schematic diagram of the pipe cutting trolley of the present invention.

[0021] Figure 5 It is a structural schematic diagram of the hoisting mechanism of the present invention.

[0022] Figure 6It is a structural schematic diagram of the one-way bearing of the present invention.

[0023] In the figure: 101. Existing pipe cutting trolley; 102. Cutter wheel device; 103. Existing plasma cutting gun; 104. Existing spiral welded pipe; 105. Guide rail; 106. Length detection sensor; 1. Pipe cutting trolley; 2. Cutter wheel; 3. Plasma cutting gun; 4. Spiral welded pipe; 5. Linear guide rail; 6. Hoisting mechanism; 7. Linear module mechanism; 8. Wire rope; 9. Hoisting wheel; 10. One-way bearing; 12. Worm gear reducer; 13. Transmission shaft; 14. Key; 15. Bearing inner ring; 16. Bearing outer ring; 17. One-way limit protrusion; 18. Wedge-shaped limit cavity. DETAILED DESCRIPTION

[0024] like Figures 2 to 6 As shown, the present invention is a device for spiral welded pipe cutting and automatic advance and retreat of the pipe cutting trolley, comprising a pipe cutting trolley 1, a cutter wheel 2, a plasma cutting gun 3, a linear guide rail 5, a hoisting mechanism 6 and a linear module mechanism 7.

[0025] like Figure 4 As shown, the pipe cutting trolley 1 is installed on the linear guide rail 5 and can reciprocate on the linear guide rail 5; a cutter wheel mounting frame and a cutting gun mounting column are provided on the pipe cutting trolley 1, and the cutting gun mounting column can adjust its position on the pipe cutting trolley 1 through a slider rail; the cutter wheel 2 is installed on the cutter wheel mounting frame through a lifting mechanism (a cylinder in this embodiment), and the plasma cutting gun 3 is installed on the cutting gun mounting column through a linear module mechanism 7, and the plasma cutting gun 3 is arranged horizontally; the hoisting mechanism 6 is installed at the end position of the linear guide rail 5.

[0026] like Figure 5 As shown, the hoisting mechanism 6 includes a wire rope 8, a hoisting wheel 9, a one-way bearing 10, a three-phase asynchronous motor, a worm gear reducer 12 and a transmission shaft 13, and also includes a fixed pulley for use. One end of the wire rope 8 is connected to the front end of the pipe cutting trolley 1, and the other end passes through the hoisting wheel 9 and is connected to the rear end of the pipe cutting trolley 1 through a fixed pulley fixed at the rear. The hoisting wheel 9 is connected to the worm gear reducer 12 and the three-phase asynchronous motor through the transmission shaft 13.

[0027] like Figure 6As shown, a one-way bearing 10 is arranged between the winch wheel 9 and the transmission shaft 13, and the one-way bearing 10 includes a key 14, a bearing inner ring 15 and a bearing outer ring 16. The bearing outer ring 16 is connected to the winch wheel 9, and the bearing inner ring 15 is connected to the transmission shaft 13. A number of freely movable keys 14 are evenly arranged between the bearing inner ring 15 and the bearing outer ring 16. The outer wall of the bearing inner ring 15 is evenly arranged with one-way limiting protrusions 17 with the same number as the key 14. A number of wedge-shaped limiting cavities 18 are formed between the outer wall of the bearing inner ring 15, the inner wall of the bearing outer ring 16 and the one-way limiting protrusion 17, and the key 14 is located inside the wedge-shaped limiting cavity 18.

[0028] A laser displacement sensor is also provided on the cutting gun mounting column.

[0029] A 650nm narrowband filter is installed inside the laser displacement sensor. This can avoid strong arc light interference during the plasma cutting process. Outside the 25mm periphery of the plasma arc, the accurate acquisition of the ranging laser signal can be basically achieved in the environment of strong plasma arc light interference. On this basis, the closed-loop position adjustment of the plasma cutting gun 3 based on PLC is carried out.

[0030] The linear module mechanism 7, the laser displacement sensor, and the three-phase asynchronous motor are all connected to the PLC controller.

[0031] The present invention also provides a method for spiral welded pipe cutting and automatic advance and retreat of a pipe cutting trolley, comprising the following steps: S1. When the cutter wheel 2 on the pipe cutting trolley 1 is lifted and in close contact with the spiral welded pipe 4, the spiral welded pipe 4 will drive the pipe cutting trolley 1 to move forward synchronously through rolling friction. When the pipe cutting trolley 1 moves forward, the wire rope 8 will provide pulling force to the winch wheel 9, driving the winch wheel 9 of the winch mechanism 6 to rotate forward (forward rotation and reverse rotation in the present invention are relative concepts).

[0032] When the outer ring 16 of the one-way bearing 10 in the winch wheel 9 is subjected to an external force and tends to rotate in the forward direction, the key 14 in the one-way bearing 10 will move toward the narrowing space of the wedge-shaped limiting cavity 18, so that the outer ring 16 and the inner ring 15 of the bearing are squeezed together more and more, and finally the inner ring 15 and the outer ring 16 of the bearing are relatively stationary. Since the worm gear reducer 12 in the winch mechanism 6 has a one-way output characteristic, it can only be input from the input end (worm) and output from the output end (worm wheel), but not output in the reverse direction. Therefore, when the inner ring 15 and the outer ring 16 of the bearing are relatively stationary, the inner ring 15 of the bearing cannot rotate in the forward direction, which in turn causes the outer ring 16 of the bearing to be unable to rotate in the forward direction.

[0033] The winch wheel 9 cannot rotate, which will cause the wire rope 8 to be tightened, making it impossible for the pipe cutting trolley 1 to move forward. The rolling friction between the cutter wheel 2 and the spiral welded pipe 4 changes to pure sliding friction, and normal plasma circular cutting of the spiral welded pipe 4 cannot be completed.

[0034] However, the hoisting mechanism 6 of the present invention drives the inner ring 15 of the bearing to rotate forward at a speed of V2 by a three-phase asynchronous motor. At the same time, the outer ring 16 of the bearing rotates at a speed of V1 under the action of an external force. The rotation directions of the outer ring 16 and the inner ring 15 of the bearing are the same, and V1 < V2. At this time, the outer ring 16 of the bearing will rotate forward under the action of the external force, and the forward speed of the pipe cutting trolley 1 is the same as the forward speed of the spiral welded pipe 4, realizing that the end face of the plasma cutting of the spiral welded pipe 4 is perpendicular to the center.

[0035] Among them, the present invention sends a signal to the frequency converter through the PLC controller. The frequency converter controls the three-phase asynchronous motor to drive the inner ring 15 of the bearing to rotate forward. The rotation speed of the inner ring 15 of the bearing is V2. After the cutter wheel 2 is in close contact with the spiral welded pipe 4, the rotation speed V1 of the outer ring 16 of the bearing is under the action of the external force of the steel wire rope 8. As long as V2 > V1, the outer ring 16 of the bearing can rotate forward; the forward speed of the pipe cutting trolley 1 is the same as the forward speed of the spiral welded pipe 4; on the contrary, when V2 < V1, the outer ring 16 of the bearing will be stuck and unable to rotate, and the forward movement of the pipe cutting trolley 1 is blocked.

[0036] S2. When the plasma cutting torch 3 cuts the spiral welded pipe 4, the linear module mechanism 7 drives the plasma cutting torch 3 to move forward or backward. The distance between the plasma cutting torch 3 and the spiral welded pipe 4 is measured non-contact by a laser displacement sensor, and the distance information is transmitted to the PLC controller. After being processed by the PLC controller, it controls the action of the linear module mechanism 7. The linear module mechanism 7 adjusts the position of the plasma cutting torch 3 in real time to ensure that the relative distance between the plasma cutting torch 3 and the spiral welded pipe 4 remains constant during the pipe cutting process, so as to ensure the normal operation of the spiral welded pipe 4 cutting operation.

[0037] S3. When the spiral welded pipe 4 is cut off, the cutter wheel 2 in close contact with the spiral welded pipe 4 drops and disengages. The hoisting wheel 9 of the hoisting mechanism 6 driven by the three-phase asynchronous motor rotates reversely, driving the pipe cutting trolley 1 to retreat. During the retreat of the pipe cutting trolley 1, the pipe cutting trolley 1 will not be controlled by the external force of the cutter wheel 2. A signal is sent through the PLC to control the three-phase asynchronous motor to drive the inner ring 15 of the bearing to rotate reversely. The key 14 in the one-way bearing 10 moves towards the space where the wedge-shaped limiting cavity 18 becomes narrower. When the inner ring 15 of the bearing rotates reversely to a certain position, the key 14 will be stuck. The inner ring 15 and the outer ring 16 of the bearing are relatively stationary and become a moving whole, and the outer ring 16 of the bearing rotates reversely accordingly, driving the pipe cutting trolley 1 back to the initial position through the steel wire rope 8.

[0038] The above has described the embodiments of the present invention in detail, but the content described is only the preferred embodiments of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equal changes and improvements made according to the scope of the present invention should still fall within the scope covered by the present invention.

Claims

1. A device for cutting spiral welded pipes and automatically advancing and retreating a pipe cutting trolley, characterized in that: It includes a pipe cutting trolley, a cutter wheel, a plasma cutting torch and a hoisting mechanism. The pipe cutting trolley is installed on a linear guide rail. A cutter wheel mounting bracket and a torch mounting column are provided on the pipe cutting trolley. The cutter wheel is installed on the cutter wheel mounting bracket through a lifting mechanism. The plasma cutting torch is installed on the torch mounting column through a linear module mechanism. The hoisting mechanism is installed at the end of the linear guide rail. The hoisting mechanism includes a steel wire rope, a hoisting wheel and a one-way bearing. One end of the steel wire rope is connected to the front end of the pipe cutting trolley, and the other end bypasses the hoisting wheel and is connected to the rear end of the pipe through a fixed pulley at the rear. The hoisting wheel is connected to a reducer and a motor through a transmission shaft. A one-way bearing is arranged between the hoisting wheel and the transmission shaft. The one-way bearing includes a key, an inner bearing ring and an outer bearing ring. The outer bearing ring is connected to the hoisting wheel, and the inner bearing ring is connected to the transmission shaft. A number of keys are evenly arranged between the inner bearing ring and the outer bearing ring. A number of one-way limiting protrusions are evenly arranged on the outer wall of the inner bearing ring. The number of the one-way limiting protrusions is the same as that of the keys. A wedge-shaped limiting cavity is formed between the inner wall of the outer bearing ring, the outer wall of the inner bearing ring and the one-way limiting protrusions. The keys are correspondingly located in the wedge-shaped limiting cavity.

2. The device for spiral welded pipe cutting and automatic advance and retreat of the pipe cutting trolley according to claim 1 is characterized in that: A laser displacement sensor is provided on the torch mounting column.

3. The device for spiral welded pipe cutting and automatic advance and retreat of the pipe cutting trolley according to claim 2 is characterized in that: A narrow-band filter with a spectrum of 650 - 680 nm is installed inside the laser displacement sensor.

4. The device for spiral welded pipe cutting and automatic advance and retreat of the pipe cutting trolley according to claim 2 is characterized in that: The linear module mechanism, the laser displacement sensor and the motor are all connected to a PLC controller.

5. The device for spiral welded pipe cutting and automatic advance and retreat of the pipe cutting trolley according to claim 1 is characterized in that: The motor is a three-phase asynchronous motor; the reducer is a worm and worm gear reducer.

6. A method for cutting spiral welded pipes and automatically advancing and retreating a pipe cutting trolley, which is realized by the device for cutting spiral welded pipes and automatically advancing and retreating a pipe cutting trolley according to any one of claims 1 to 5, characterized in that: It includes the following steps: S1. Driving the pipe cutting trolley forward with a dual power source: When the cutter wheel on the pipe cutting trolley is lifted and in close contact with the spiral welded pipe, the spiral welded pipe drives the pipe cutting trolley to move forward synchronously through rolling friction. When the pipe cutting trolley moves forward, the steel wire rope will provide a pulling force to the hoisting wheel, driving the outer bearing ring of the hoisting wheel of the hoisting mechanism to rotate forward. The rotational speed of the outer bearing ring under the action of external force is V1. At the same time, the inner bearing ring is driven to rotate forward by the motor with a rotational speed of V2. The outer bearing ring and the inner bearing ring rotate in the same direction, and when V1 < V2, the outer bearing ring rotates forward, and the pipe cutting trolley moves forward to realize the plasma circumferential cutting of the spiral welded pipe. S2. Cutting the spiral welded pipe: When the plasma cutting torch cuts the spiral welded pipe, the linear module mechanism drives the plasma cutting torch to move forward or backward to maintain a certain distance between the plasma cutting torch and the spiral welded pipe. S3. Driving the pipe cutting trolley backward with a single power source: When the spiral welded pipe is cut off, the cutter wheel in contact with the spiral welded pipe drops and disengages. The motor drives the inner bearing ring to rotate reversely. The keys in the one-way bearing move towards the space where the wedge-shaped limiting cavity becomes narrower, making the relative rotational speed between the outer bearing ring and the inner bearing ring decrease. Until the keys are stuck, the outer bearing ring and the inner bearing ring become relatively stationary as a whole, and the outer bearing ring随之 rotates reversely, driving the pipe cutting trolley back to the initial position through the steel wire rope.

7. The method for spiral welded pipe cutting and automatic advance and retreat of the pipe cutting trolley according to claim 6, characterized in that: In step S2, the distance between the plasma cutting torch and the spiral welded pipe is measured non-contact by the laser displacement sensor, and the distance information is transmitted to the PLC controller. After being processed by the PLC controller, it controls the action of the linear module mechanism.

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