Edge cutting tool for automatic wire breaking of pipeline

Abstract

The invention discloses an edge cutting tool for automatic wire breaking of a pipeline, and belongs to the technical field of pipeline engineering, the edge cutting tool comprises a rotary drum and at least two telescopic assemblies arranged along the circumference of the rotary drum, each telescopic assembly is matched with a cutting assembly, and the cutting assemblies are fixed to the ends, deviating from the rotary drum, of the radial telescopic assemblies; each cutting assembly comprises two supporting lugs fixedly connected with the radial telescopic assemblies, tool bits fixed to the ends, away from the rotary drum, of the supporting lugs, wheel shafts rotationally connected with the supporting lugs, hubs and rotary cutting cutterheads, the hubs and the rotary cutting cutterheads are coaxially and fixedly connected with the wheel shafts, the hubs are sleeved with tires, and during cutting work, the tires make contact with the inner wall of the pipeline and drive the wheel shafts to rotate; and therefore, the rotary cutter head is driven to continuously rotate, and the strip-shaped skirt edge cut by the cutter is automatically cut off. According to the invention, the skirt edge in the pipeline can be rotationally cut, and meanwhile, the strip-shaped skirt edge generated after cutting can be automatically cut off.

Description

Technical Field

[0001] The invention relates to the technical field of pipeline engineering, in particular to the technical field of pipeline construction, and specifically to an edge trimming tool for automatically cutting wires of pipelines. Background Art

[0002] PE pipe, or fiber-reinforced composite pipe, can be used in high-pressure occasions such as oil and gas transportation. The pipe needs to be cleaned regularly due to the medium transportation requirements. The fiber-reinforced composite pipe is composed of an inner lining layer, a reinforcement layer and a protective layer. The inner lining layer adopts the PE pipe hot-melt butt method during docking, which will cause the existence of a skirt inside after docking, affecting the cleaning of the pipe and increasing the medium resistance, which will limit its application in the field of large-diameter high-pressure oil and gas transportation. At present, large-diameter pipeline docking uses an in-pipe robot to assist in docking construction, and the in-pipe robot is also required to remove the inner wall skirt. Due to the strong toughness and ductility of PE pipes, filamentous waste is often generated during the skirt cutting process. Due to the complex structure of the in-pipe robot, the skirt cutting is too long, which will cause the related parts to get stuck, causing the machine parts to fail to operate normally. Therefore, it is necessary to cut the skirt inside the pipe, and the wire needs to be broken, that is, the cut skirt is cut into short sections. The existing technology has no mature solution to the above engineering problems. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a pipe edge trimming tool with automatic wire cutting, which can cut the skirt edge and automatically cut off the cut skirt edge.

[0004] In order to achieve the above object, the solution provided by the present invention is as follows:

[0005] A pipe automatic wire cutting edge cutting tool, comprising:

[0006] A rotating assembly, the rotating assembly includes a rotating drum, and the rotating assembly is used to drive the rotating drum to rotate around its center line;

[0007] At least two radial telescopic components, all of which are arranged along the circumference of the drum, and each radial telescopic component has one end fixedly connected to the drum and the other end being a free end extending radially outwardly along the drum;

[0008] Cutting assembly, each radial telescopic assembly is equipped with a cutting assembly, the cutting assembly is carried on the free end of the corresponding radial telescopic assembly, and is used to cut the inner skirt of the pipe. Each cutting assembly includes:

[0009] A base fixedly connected to the free end of the radial telescopic assembly;

[0010] Two support ears spaced a certain distance apart, one end of each of the two support ears being fixedly connected to the support and the other end being a free end extending radially outwardly along the drum;

[0011] A cutter head carried on the free ends of the two lugs is used to cut the skirt between the two lugs;

[0012] A wheel axle rotatably connected to the middle of the two ears, the wheel axle being arranged along the axial direction of the drum;

[0013] The rotary cutting disc is located between the two support ears and is coaxially fixedly connected to the wheel axle; it is used to cut off the skirt cut by the cutter head;

[0014] A wheel hub coaxially fixedly connected to the wheel axle;

[0015] The tire mounted on the wheel hub is made of elastic material, so that when the cutter head cuts the skirt in the pipe, the tire abuts against the inner wall of the pipe. When the rotating component drives the radial telescopic component to rotate, the tire abuts against the inner wall of the pipe, driving the rotary cutting disc fixedly connected to the wheel axle to rotate, thereby cutting off the skirt cut by the cutter head.

[0016] As a specific implementation of the present invention, a cutting knife is arranged on the radial edge of the rotary cutter disc.

[0017] As a specific embodiment of the present invention, the blade head includes a blade body and a connection end. The blade body is a quadrangular prism structure. The blade body includes a top surface, a cutting surface, a bottom surface and a transition surface connected end to end. The angle between the connection part of the top surface and the cutting surface is an acute angle. When the blade head is in a cutting state, the connection part of the top surface and the cutting surface contacts the inner wall contour of the pipe, thereby cutting. The angle between the connection part of the cutting surface and the bottom surface is an obtuse angle. The connection part of the cutting surface and the bottom surface and the cutter clearance of the edge of the rotary cutter disc cooperate, so that the rotary cutter disc can cut off the skirt cut by the blade head.

[0018] As a specific embodiment of the present invention, when the tire is subjected to radial inward extrusion and reaches the limit position, the cutting range of the cutter head is equal to the inner diameter of the pipe. In this way, the skirt can be fully cut and excessive cutting of the pipe can be avoided to cause grooves in the pipe.

[0019] As a specific embodiment of the present invention, the rotating assembly further includes:

[0020] A center tube coaxially sleeved in the drum;

[0021] A base and a retaining ring are fixed to the outer wall of the central tube, the base and the retaining ring are spaced a certain distance apart along the axial direction of the central tube, and the rotating drum is located between the base and the retaining ring;

[0022] A gear ring coaxially fixedly connected to the outer wall of the drum;

[0023] The power mechanism carried on the base is used to drive the pinion to rotate, wherein the pinion is meshed with the ring gear.

[0024] As a specific embodiment of the present invention, the radial telescopic assembly further includes:

[0025] A cylinder body with one end fixedly connected to the drum and the other end extending radially along the drum, wherein a stepped hole is provided in the drum; the stepped hole has the largest diameter close to the drum and gradually decreases in diameter outward along the drum radial direction;

[0026] A piston rod having one end extending into the cylinder body and the other end extending outward along the axial direction of the drum and passing through the cylinder body and fixedly connected to the cutting assembly;

[0027] A guide structure for guiding the piston rod to move only along the axial direction of the drum;

[0028] A small piston is slidably connected to the inner wall of the drum, and one end of the piston rod located in the cylinder is fixedly connected to the small piston;

[0029] A large piston slidably connected to the inner wall of the drum, and the large piston and the inner wall of the drum are sealed;

[0030] A tension spring located between the large piston and the small piston;

[0031] A return spring is used to push the small piston toward the large piston.

[0032] Furthermore, the guide structure comprises:

[0033] A slide groove located on the outer wall of the piston rod and extending along the axial direction of the piston rod;

[0034] A positioning pin fixedly connected to the cylinder body and slidably connected to the slide groove.

[0035] Furthermore, the device also includes a flow channel combination for providing fluid to the sealed cavity of the large piston near the central tube in the cylinder body, and the flow channel combination includes:

[0036] An annular groove is located on the base, and two side walls of the annular groove are sealed and connected to the drum;

[0037] A first flow channel located on the base and connected to the annular groove, used to introduce external fluid into the annular groove;

[0038] The second flow channel is located on the rotating drum, one end of the second flow channel is connected with the annular groove, and the other end is connected with the sealing cavity of the large piston inside the cylinder body close to one end of the central tube.

[0039] A method for cutting the inner skirt of a pipe, using the above-mentioned pipe automatic wire cutting edge cutting tool to cut the inner skirt of the pipe, comprising the following steps:

[0040] The automatic wire cutting tool for pipeline is placed in the pipeline and the center tube is fixed. Compressed gas is injected into the first flow channel on the base. The gas enters the cylinder through the flow channel combination and drives the large piston to move radially outward. The large piston pushes the tightening spring and pushes the small piston radially out. The cutting assembly presses against the inner wall of the pipeline, and the cutting edge of the cutter head is embedded in the inner skirt of the pipeline.

[0041] The power mechanism rotates through the gears, thereby driving the drum to rotate, and the tire rolls against the inner wall of the pipe. The tire drives the rotary cutter disc to rotate and cut the strip skirt cut by the cutter head into short sections.

[0042] When resetting, the pressure in the cylinder is released and the return spring pushes the small piston to retract radially.

[0043] Compared with the existing technology, it has the following advantages:

[0044] The present invention can perform rotational cutting on the skirt inside the pipe, and can automatically cut off the strip skirt produced after cutting, so as to avoid the influence of excessively long cut wires on the work of the pipe docking robot; the device can remove the skirt inside the PE pipe and the fiber reinforced composite pipe, so as to ensure its passability and facilitate the pipe cleaning operation; it adopts multiple groups of cutting components to cut at the same time, so the working efficiency is high, and the whole circle of skirt inside the pipe can be cut in less than one rotation of the rotating drum.

[0045] After the large piston moves to the position farthest from the center tube, the large piston pushes the small piston radially out through the tightening spring; in this way, the extrusion pressure between the cutting assembly and the inner wall of the pipe is mainly determined by the tightening spring, the return spring, and the self-gravity of the cutting assembly, rather than by the fluid pressure in the cylinder; the relevant extrusion pressure is directly determined by the mechanical components to avoid the influence of the driving fluid pressure fluctuation on the cutting effect.

[0046] The cutting assembly is pressed against the inner wall of the pipe by spring force, and the cutting assembly can automatically adapt to the inner diameter error of the pipe and the installation deviation of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a cross-sectional view of the edge cutting tool for automatic wire cutting of pipeline in Example 1;

[0048] Figure 2 for Figure 1 A cross-sectional view of the radial telescopic assembly;

[0049] Figure 3 for Figure 1 A cross-sectional view of the cutting assembly;

[0050] Figure 4 for Figure 1 Schematic diagram of the combined arrangement of the middle cutter head and the rotary cutting cutter disc;

[0051] Figure 5 for Figure 1Schematic diagram of the structure of the middle cutter head;

[0052] Figure 6 A schematic diagram of a process of cutting a skirt edge by an edge cutting tool according to a specific embodiment of the present invention;

[0053] In the figure: center tube 11; base 12; drum 13; pneumatic motor 14; gear ring 15; pinion 16; retaining ring 17;

[0054] Cylinder body 21; large piston 22; tension spring 23; small piston 24; return spring 25; piston rod 26; positioning pin 27;

[0055] Base 31; pin 32; lug 33; tire 34; wheel hub 35; end cover 36; sealing felt ring 37; axle 38; bearing 39; rotary cutter disc 310; cutter head 311; pipeline inner wall profile 40;

[0056] The top surface 3111 of the cutter head; the cutting surface 3112 of the cutter head; the bottom surface 3113 of the cutter head; and the transition surface 3114 of the cutter head. DETAILED DESCRIPTION

[0057] The present invention will be further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0058] Example

[0059] Please refer to Figure 1 to Figure 5 , which shows the specific structure of the automatic wire cutting tool for pipelines of this embodiment. The automatic wire cutting tool for pipelines of this embodiment includes a rotating component, a radial telescopic component, and a cutting component.

[0060] The rotating assembly includes a central tube 11, a base 12, a rotating drum 13, an air motor 14, a gear ring 15, a pinion 16 and a retaining ring 17, which are used to drive the rotating drum 13 to rotate relative to the central tube 11. The central tube 11 is placed at the center of the pipeline, and the central tube 11 is cylindrical as a whole; the rotating drum 13 is cylindrical as a whole, and the rotating drum 13 is sleeved in the middle position outside the central tube 11. The base 12 is set at one end of the rotating drum 13, and the retaining ring 17 is set at the other end. The retaining ring 17 is annular in shape and fixed to the central tube 11. The base 12 is fixed to the central tube 11, so that the rotating drum 13 can only rotate on the outer wall of the central tube 11 between the base 12 and the retaining ring 17, and it is prevented from shaking along the axial direction of the central tube 11. The air motor 14 is installed on the base 12. The gear ring 15 is set on the side of the rotating drum 13 close to the air motor 14, and the gear ring 15 is fixedly connected to the rotating drum 13. The output shaft of the air motor 14 is provided with a pinion 16, which meshes with the ring gear 15, so that the air motor 14 drives the drum 13 to rotate relative to the central tube 11. In other embodiments, the air motor 14 may also be replaced by other rotary power devices such as an electric motor.

[0061] There are multiple radial telescopic assemblies, all of which are arranged in an array along the circumference of the rotating cylinder 13. Each radial telescopic assembly includes a cylinder body 21, a large piston 22, a tension spring 23, a small piston 24, a return spring 25, a piston rod 26 and a positioning pin 27. The cylinder body 21 is cylindrical in shape as a whole, one end of which is fixedly connected to the rotating cylinder 13, and the other end extends radially outward along the rotating cylinder 13. A step hole is arranged in the cylinder body 21, and the step hole has the largest diameter close to the rotating cylinder side and gradually decreases radially outward along the rotating cylinder. A large piston 22 is arranged on the side of the cylinder body 21 close to the rotating cylinder 13, and a sealing ring is arranged between the large piston 22 and the inner wall of the cylinder body 21 to seal, so that the large piston 22 can be driven to move axially along the cylinder body 21 by filling and discharging gas into the cavity between the large piston 22 and the rotating cylinder 13. A small piston 24 is arranged on the side of the cylinder body 21 away from the rotating cylinder 13, and one end of the piston rod 26 is connected to the small piston 24 and the other end extends out of the cylinder body. Inside the cylinder 21, a return spring 25 is arranged in the chamber where the piston rod 26 is located, which is used to push the small piston 24 to move toward the rotating drum 13; a tension spring 23 is arranged between the small piston 24 and the large piston 22, which is used to push the two to move in opposite directions along the axial direction of the cylinder 21. A positioning pin 27 is arranged at the end of the cylinder 21 on one side of the piston rod 26, and an axial sliding groove is arranged at the position of the positioning pin 27 of the piston rod 26. One end of the positioning pin 27 extends into the sliding groove, so that the positioning pin 27 and the sliding groove are slidably connected, thereby fixing the piston rod 26 circumferentially to prevent it from rotating.

[0062] There are multiple cutting assemblies, each of which corresponds to a radial telescopic assembly, and the cutting assembly is installed at the end of the radial telescopic assembly away from the rotation, and is used to cut the inner skirt of the pipe. Each cutting assembly includes a base 31, a pin 32, a lug 33, a tire 34, a hub 35, an end cover 36, a sealing felt ring 37, an axle 38, a bearing 39, a rotary cutter disc 310 and a cutter head 311. The base 31 is cylindrical, and the base 31 is sleeved on the end of the piston rod 26 and fixed with a pin 32. Two lugs 33 are set on the side of the base 31 away from the piston rod 26, and through holes are set in the middle of the two lugs 33. The rotary cutter disc 310 is a disc with a center hole as a whole and is arranged between the two lugs 33. The axle 38 is a stepped shaft with a thick middle and thin ends, and the axle 38 passes through the lug 33 and the center hole of the rotary cutter disc 310. The middle of the axle 38 is connected with the rotary cutter disc 310 by a keyway so that the two can rotate synchronously. The two ends of the axle 38 are equipped with a hub 35, and a tire 34 is arranged on the outer side of the hub 35. A bearing 39 is arranged between the axle 38 and the lug 33 so that the two are connected in rotation. Round nuts are arranged at both ends of the axle 38 to axially fix the hub 35. The hub 35 and the axle 38 are connected by a keyway so that the two rotate synchronously. The tire 34 is made of elastic material. In the working state, the tire 34 is pressed against the inner wall profile 40 (protruding skirt) of the pipe. When the drum 13 rotates around the central pipe 11, the tire 34 rotates to drive the rotary cutter disc 310 to rotate. The end cover 36 is disc-shaped as a whole. The end cover 36 is fixed to the lug 33 by screws. The inner side of the end cover 36 is gap-connected with the hub 35 and a sealing felt ring 37 is arranged. A cutter is arranged on the radial edge of the rotary cutter disc 310. The rotary cutter disc 310 is a gear-like structure as a whole, and its shape is similar to that of a spur gear. The cutter head 311 is fixed at one end of the two ears 33 away from the rotating drum 13, and is used to cut the skirt between the two ears 33. Each cutter head 311 includes a cutter body and a connecting end. The cutter body is a quadrangular prism structure, and the cutter body includes a cutter head top surface 3111, a cutter head cutting surface 3112, a cutter head bottom surface 3113 and a cutter head transition surface 3114 connected end to end. Among them, the angle between the connecting part of the cutter head top surface 3111 and the cutter head cutting surface 3112 is an acute angle. When the cutter head 311 is in a cutting state, this part contacts the inner wall contour 40 (protruding skirt) of the pipe, thereby cutting. The angle between the connecting part of the cutter head cutting surface 3112 and the cutter head bottom surface 3113 is an obtuse angle. This part cooperates with the cutter gap at the edge of the rotary cutter disc 310, so that the rotary cutter disc 310 can cut off the strip skirt cut by the cutter head 311. The cutter head transition surface 3114 connects the cutter head top surface 3111 and the cutter head bottom surface 3113. Both ends of the cutter body are fixed to the connecting ends, and the connecting ends are fixed to the ends of the support ears 33.

[0063] Channel setting: An annular groove is provided at one end of the base 12 close to the drum 13. The annular groove is located outside the drum 13, and both sides of the annular groove are sealed and connected to the drum 13. In order to enhance the sealing performance, rubber rings can be provided on both sides of the annular groove to seal the gap between the drum 13 and the base 12 to prevent the fluid in the annular groove from leaking from the gap. A first channel connected to the annular groove is provided on the base 12 to introduce the external fluid into the annular groove. A second channel is also provided on the drum 13. One end of the second channel is connected to the annular groove, and the other end is connected to the sealed cavity of the large piston 22 inside the cylinder 21 close to one end of the central tube 11. When used specifically, the external gas source can be connected to the first channel, and the gas flows through the first channel, the annular groove and the second channel in sequence, and then enters the cylinder 21 to push the large piston 22 to move radially outward along the drum 13. When the gas flows in the opposite direction along the channel, the large piston 22 moves radially inward along the drum 13 under the action of the relevant spring, thereby controlling the movement of the large piston 22.

[0064] In addition, by placing the skirt between the two tires 34, the cutting range of the cutter head 311 can be controlled by the radial deformation of the tires 34. When the tires 34 are subjected to radial inward extrusion and reach the limit position, the cutting range of the cutter head 311 is equal to the inner diameter of the pipe. In this way, the skirt can be fully cut, and excessive cutting of the pipe can be avoided to cause grooves in the pipe. Figure 6 As shown, a steel wheel fixedly connected to the wheel hub 35 is arranged outside the tire 34, and the tire is in contact with the tube wall all the time. As the skirt is cut, the wheel continuously moves radially outward, and the tire continuously deforms under radial pressure. When the wheel contacts the tube wall, the tire is subjected to radial extrusion to the limit position, at which time the skirt is completely cut.

[0065] A method of using this embodiment is as follows:

[0066] The device is placed at the center of the pipeline and the center tube is fixed. Compressed gas is injected through the flow channel hole of the base. The gas is sent into the cylinder through the flow channel and drives the large piston to move radially outward. The large piston pushes the tightening spring and pushes the small piston radially out. The cutting assembly presses against the inner wall of the pipeline, and the cutting edge of the cutter head is embedded in the inner skirt of the pipeline.

[0067] The pneumatic motor drives the drum to rotate through gear transmission, and the tire rolls against the inner wall of the pipe. The tire drives the rotary cutter disc to rotate and cuts the strip skirt cut by the cutter head into short sections.

[0068] When resetting, the pressure in the cylinder is released and the return spring pushes the small piston to retract radially.

[0069] In the present invention, after the large piston moves to the position farthest from the central tube, the large piston pushes the small piston radially out through the tensioning spring; in this way, the extrusion pressure between the cutting assembly and the inner wall of the pipe is mainly determined by the tensioning spring, the return spring, and the self-gravity of the cutting assembly, rather than by the fluid pressure in the cylinder body; the relevant extrusion pressure is directly determined by the mechanical components to avoid the influence of the driving fluid pressure fluctuation on the cutting effect.

[0070] On the other hand, since the cutting assembly is pressed against the inner wall of the pipe by the spring force, the cutting assembly can automatically adapt to the inner diameter error of the pipe and the installation deviation of the device.

[0071] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed in the embodiments of the present invention should be covered within the protection scope of the present invention.

Claims

1. A pipe automatic wire cutting tool, characterized in that: include: A rotating assembly, the rotating assembly includes a rotating drum, and the rotating assembly is used to drive the rotating drum to rotate around its center line; At least two radial telescopic components, all of which are arranged along the circumference of the drum, and each radial telescopic component has one end fixedly connected to the drum and the other end being a free end extending radially outwardly along the drum; Cutting assembly, each radial telescopic assembly is equipped with a cutting assembly, the cutting assembly is carried on the free end of the corresponding radial telescopic assembly, and is used to cut the inner skirt of the pipe. Each cutting assembly includes: A base fixedly connected to the free end of the radial telescopic assembly; Two support ears spaced a certain distance apart, one end of each of the two support ears being fixedly connected to the support and the other end being a free end extending radially outwardly along the drum; A cutter head carried on the free ends of the two lugs is used to cut the skirt between the two lugs; A wheel axle rotatably connected to the middle of the two ears, the wheel axle being arranged along the axial direction of the drum; The rotary cutting disc is located between the two support ears and is coaxially fixedly connected to the wheel axle; it is used to cut off the skirt cut by the cutter head; A wheel hub coaxially fixedly connected to the wheel axle; The tire is sleeved on the wheel hub and is made of elastic material so that when the cutter head cuts the skirt in the pipe, the tire abuts against the inner wall of the pipe.

2. The automatic wire cutting edge trimming tool for pipelines according to claim 1, characterized in that: A cutting knife is arranged on the radial edge of the rotary cutter disc.

3. The automatic wire cutting edge trimming tool for pipelines according to claim 2, characterized in that: The cutter heads all include a cutter body and a connecting end. The cutter body is a quadrangular prism structure, and includes a top surface, a cutting surface, a bottom surface and a transition surface connected end to end. The angle between the connecting portion of the top surface and the cutting surface is an acute angle. When the cutter head is in a cutting state, the connecting portion of the top surface and the cutting surface contacts the inner wall contour of the pipe, thereby performing cutting. The angle between the connecting portion of the cutting surface and the bottom surface is an obtuse angle. The connecting portion of the cutting surface and the bottom surface and the cutting clearance of the edge of the rotary cutting disc cooperate, so that the rotary cutting disc can cut off the skirt cut by the cutter head.

4. The automatic wire cutting edge trimming tool for pipelines according to claim 1, characterized in that: When the tire is subjected to radial inward extrusion and reaches a limit position, the cutting range of the cutter head is equal to the inner diameter of the pipe.

5. The automatic wire cutting edge trimming tool for pipelines according to claim 1, characterized in that: The rotating assembly further comprises: A center tube coaxially sleeved in the drum; A base and a retaining ring are fixed to the outer wall of the central tube, the base and the retaining ring are spaced a certain distance apart along the axial direction of the central tube, and the rotating drum is located between the base and the retaining ring; A gear ring coaxially fixedly connected to the outer wall of the drum; The power mechanism carried on the base is used to drive the pinion to rotate, wherein the pinion is meshed with the ring gear.

6. The automatic wire cutting edge trimming tool for pipelines according to claim 5, characterized in that: The radial telescopic assembly also includes: A cylinder body with one end fixedly connected to the drum and the other end extending radially along the drum, wherein a stepped hole is provided in the drum; the stepped hole has the largest diameter close to the drum and gradually decreases in diameter outward along the drum radial direction; A piston rod having one end extending into the cylinder body and the other end extending outward along the axial direction of the drum and passing through the cylinder body and fixedly connected to the cutting assembly; A guide structure for guiding the piston rod to move only along the axial direction of the drum; A small piston is slidably connected to the inner wall of the drum, and one end of the piston rod located in the cylinder is fixedly connected to the small piston; A large piston slidably connected to the inner wall of the drum, and the large piston and the inner wall of the drum are sealed; A tension spring located between the large piston and the small piston; A return spring is used to push the small piston toward the large piston.

7. The automatic wire cutting edge trimming tool for pipelines according to claim 6, characterized in that: The guiding structure comprises: A slide groove located on the outer wall of the piston rod and extending along the axial direction of the piston rod; A positioning pin fixedly connected to the cylinder body and slidably connected to the slide groove.

8. The automatic wire cutting edge trimming tool for pipelines according to claim 6, characterized in that: The tool also includes a flow channel assembly for providing fluid to a sealing cavity of a large piston in the cylinder body close to the center tube, the flow channel assembly including: An annular groove is located on the base, and two side walls of the annular groove are sealed and connected to the drum; A first flow channel located on the base and connected to the annular groove, used to introduce external fluid into the annular groove; The second flow channel is located on the rotating drum, one end of the second flow channel is connected with the annular groove, and the other end is connected with the sealing cavity of the large piston inside the cylinder body close to one end of the central tube.

9. A method for cutting the inner skirt of a pipe, characterized in that: Using the automatic wire-breaking pipe trimming tool according to claim 8 to cut the inner skirt of the pipe comprises the following steps: The automatic wire cutting tool for pipeline is placed in the pipeline and the center tube is fixed. Compressed gas is injected into the first flow channel on the base. The gas enters the cylinder through the flow channel combination and drives the large piston to move radially outward. The large piston pushes the tightening spring and pushes the small piston radially out. The cutting assembly presses against the inner wall of the pipeline, and the cutting edge of the cutter head is embedded in the inner skirt of the pipeline. The power mechanism rotates through the gears, thereby driving the drum to rotate, and the tire rolls against the inner wall of the pipe. The tire drives the rotary cutter disc to rotate and cut the strip skirt cut by the cutter head into short sections; When resetting, the pressure in the cylinder is released and the return spring pushes the small piston to retract radially.

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