An apparatus for cutting within an underground metal pipe

Abstract

The application provides an internal cutting device suitable for an underground vertical metal pipeline, which comprises a support fixing system (1), a cutting system (2), a feeding system (3) and a damping system (4), and is characterized in that the support fixing system (1) is divided into two groups, the support fixing system (1) comprises a mounting cylinder (1.1), a bottom disc (1.2), a movable support arm (1.3), a rotating disc (1.4), a bevel gear (1.5), a first driving motor (1.6) and a connecting cylinder (1.7); the cutting system (2) comprises a shell (2.1), two rollers (2.2), a second driving motor (2.3) and a cutting tool head (2.4); the feeding system (3) is divided into a radial feeding part and a circumferential feeding part; and the damping system (4) comprises a deep groove ball bearing (4.1) and an adjustable ring damper (4.2). The device can effectively prevent resonance of the cutting device and the pipeline. Compared with other internal cutting devices, the device greatly improves cutting efficiency and cutting precision, reduces tool wear and improves safety.

Description

Technical Field

[0001] This invention relates to the field of industrial pipeline processing technology, specifically an internal cutting device suitable for underground vertical metal pipelines. Technical Background

[0002] Currently, industrial pipelines are mostly processed by external cutting. In most cases, external pipe cutting devices can meet the needs of industrial production. However, in special conditions such as pipelines buried deep underground, internal pipe cutting is the only option. When performing internal pipe cutting, the cutting device must be fixed to the pipe wall. Therefore, the high-speed rotation of the cutting tool and transmission components inevitably causes high-frequency vibrations in both the cutting device and the pipe. When the pipe diameter is small, resonance is highly likely to occur. This resonance reduces cutting efficiency, decreases processing accuracy, accelerates tool wear, and may even pose safety hazards.

[0003] Current internal cutting machines use hydraulic rods or screw jacks as fixing devices. For example, patent CN101982276 B only uses hydraulic components for fixing on both sides of the inner wall of the pipe, utilizing the principle of the longest diameter on the circumference. While theoretically the device can be fixed in the center of the pipe, in practice it is prone to deviation. When the device vibrates during operation, it may fall off due to instability. Although hydraulic components have good rigidity, they lack the ability to eliminate resonance. In general, current internal cutting machines mainly suffer from the following problems: First, some consider the impact of resonance during cutting but lack measures to eliminate it. Second, some support and fixing devices have poor fixing effects, while those with good fixing effects are bulky, complex in structure, and occupy a large amount of internal space. Summary of the Invention

[0004] This invention provides a tension-type internal pipe cutting device suitable for vertical metal pipes. This device can achieve internal cutting of pipes deep underground, is compatible with pipes of different diameters and thicknesses, is securely fixed, has good overall structural rigidity, and is equipped with an independent vibration damping system to prevent resonance. It offers high cutting efficiency and high processing precision.

[0005] To achieve the above objectives, the present invention provides: 1. An internal cutting device suitable for underground vertical metal pipes, comprising a support and fixing system, a cutting system, a feeding system, and a vibration damping system, characterized in that:

[0006] The support and fixing system is divided into upper and lower groups. The support and fixing system includes a mounting cylinder, a chassis, a movable support arm, a rotating plate, a bevel gear, a first drive motor, and a connecting cylinder.

[0007] The swivel plate is fixed inside the mounting cylinder by the base plate;

[0008] Three movable support arms are installed in the grooves at the top of the mounting cylinder, and the threads below engage with the flat threads of the rotating disc;

[0009] The bevel gear is placed on the side of the mounting cylinder and meshes with the disc gear surface of the rotating disc, while the other end is connected to the first drive motor.

[0010] The connecting cylinder is used to connect the upper and lower sets of support and fixing systems;

[0011] The cutting system includes a housing, two rollers, a second drive motor, and a cutting head.

[0012] Two rollers are mounted on the outside of the housing, and the second drive motor is integrated inside the housing and connected to the cutting head.

[0013] The feed system is divided into two parts: radial feed and circumferential feed.

[0014] The vibration reduction system includes a deep groove ball bearing and an adjustable annular damper; the deep groove ball bearing is installed with an interference fit to the lower end of the connecting shaft; the adjustable annular damper is fixed in a groove on the mounting cylinder and connected to the connecting shaft through the deep groove ball bearing.

[0015] Furthermore, one side of the rotating disc is a disc-shaped gear, and the other side is a flat thread.

[0016] Furthermore, the housing is supported by four support rods and two rollers.

[0017] Furthermore, the radial feed section includes a base, two hydraulic telescopic rods, and eight support rods; the eight support rods and the two hydraulic telescopic rods are symmetrically installed on the left and right sides of the base. The support rods are connected to the housing to form two sets of symmetrical parallel double-crank mechanisms. The housing serves as a connecting rod, the support rods serve as cranks, and the base simultaneously acts as the frame for the two sets of parallel double-crank mechanisms. The two hydraulic telescopic rods are respectively installed on two opposite corners of the two parallel double-crank mechanisms as driving devices.

[0018] Furthermore, the circumferential feed section includes a thrust bearing, a connecting shaft, and a third drive motor. The connecting shaft, used for the transmission between the third drive motor and the base, is installed within the mounting cylinder, while the third drive motor is housed within the connecting cylinder. Circumferential feed occurs after the radial feed is completed, when the third drive motor, via the connecting shaft, drives the entire cutting system to move in a circular motion around the inner wall of the pipe.

[0019] This invention also provides an internal cutting device suitable for underground vertical metal pipes and a method for internal cutting of underground vertical metal pipes, characterized in that:

[0020] Step 1: Determine the optimal radial feed rate based on the wall thickness of the metal pipe to be cut; use rollers of different diameters to make the radial distance between the cutting head and the roller equal to the radial feed rate; then lower the entire device to the specified cutting depth using ropes.

[0021] Step 2: Support and fixation system operation; Two first drive motors drive the movable extension arm to expand outward along the groove on the mounting cylinder to the inner wall of the pipe and fix it through the transmission of bevel gears and rotating disc; Utilizing the self-locking property of the engagement between the flat Archimedean spiral groove on the rotating disc and the thread below the movable extension arm, the entire device is firmly fixed to the center of the pipe profile.

[0022] Step 3: The second drive motor drives the cutting head to start rotating, and the cutting system starts to run; then the feed system starts, the two hydraulic telescopic rods extend, and the two sets of cutting systems move parallel to the pipe wall under the action of the parallel double crank mechanism until the four rollers are in full contact with the pipe wall and then the extension stops.

[0023] Step 4: Begin circumferential feeding. The third drive motor drives the connecting shaft to rotate, and the roller begins to roll along the inner wall of the pipe. The cutting head begins to cut circumferentially along the pipe. After rotating more than half a turn, the pipe is completely cut off.

[0024] Step 5: The second drive motor stops, the two hydraulic telescopic rods shorten, and the cutting system is driven to retract towards the center via the parallel double crank mechanism; then the two first drive motors reverse, and through the transmission of bevel gears and rotating discs, drive the movable extension arm to retract inward along the groove on the mounting cylinder, completely separating the inner cutting device from the pipe, and then the device is retrieved via rope.

[0025] Compared with other existing pipe cutting devices, the advantages of this invention are:

[0026] 1. Stable support and good structural rigidity. This invention uses a structure similar to a three-jaw chuck as a support and fixing device. Due to the self-locking and self-centering properties of this structure, this invention achieves stable support for the cutting system in pipes with a large diameter range within a very small space.

[0027] 2. Effectively prevents resonance between the cutting device and the pipeline. It provides comprehensive vibration reduction measures, significantly improving cutting efficiency and accuracy compared to other internal cutting devices, reducing tool wear, and enhancing safety. Attached Figure Description

[0028] The advantages of the above and / or additional aspects of this application will become apparent and readily understood in the description of the embodiments in conjunction with the following drawings, wherein:

[0029] Figure 1 This is a schematic diagram of the overall structure of the pipe cutting device of the present invention;

[0030] Figure 2 This is a cross-sectional schematic diagram of the support and fixing system of the present invention;

[0031] Figure 3 This is a schematic diagram of the adjustable annular damper structure of the present invention;

[0032] The components are as follows: 1-Support and fixing system: 1.1-Mounting cylinder; 1.2-Chassis; 1.3-Movable support arm; 1.4-Spinning disc; 1.5-Bevel gear; 1.6-First drive motor; 1.7-Connecting cylinder; 1.8-Three-jaw hook; 2-Cutting system: 2.1-Housing; 2.2-Roller; 2.3-Second drive motor; 2.4 Cutting head; 3-Feeding system: 3.1-Base; 3.2-Hydraulic telescopic rod; 3.3-Support rod; 3.4-Thrust bearing; 3.5-Connecting shaft; 3.6-Third drive motor; 4-Vibration damping system: 4.1-Deep groove ball bearing; 4.2-Adjustable annular damper; 4.2.1-Annular sealing cylinder; 4.2.2-Annular spring; 4.2.3-Piston ring. Detailed Implementation

[0033] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0034] like Figure 1 As shown, this embodiment provides an internal cutting device suitable for underground vertical metal pipes, including a support and fixing system 1, a cutting system 2, a feeding system 3, and a vibration damping system 4.

[0035] The support and fixing system 1 is divided into upper and lower groups to improve overall rigidity and reduce vibration. The support and fixing system 1 includes a mounting cylinder 1.1, a chassis 1.2, a movable support arm 1.3, a rotating plate 1.4, a bevel gear 1.5, a first drive motor 1.6, and a connecting cylinder 1.7.

[0036] One side of the rotating disc 1.4 is a disc-shaped gear, and the other side is a flat thread (Archimedean spiral groove), which is fixed inside the mounting cylinder 1.1 by the base 1.2.

[0037] Three movable support arms 1.3 are installed in the grooves on the upper part of the mounting cylinder 1.1, and the threads below engage with the flat threads of the rotating disc 1.4.

[0038] The bevel gear 1.5 is placed on the side of the mounting cylinder 1.1 and meshes with the disc gear surface of the rotating disc 1.4. The other end is connected to the first drive motor 1.6.

[0039] When the first drive motor 1.6 rotates, it drives the three movable support arms 1.3 to move outward at the same speed.

[0040] The connecting cylinder 1.7 is used to connect the upper and lower sets of support and fixing systems 1.

[0041] The cutting system 2 is divided into two groups, each group including: housing 2.1, two rollers 2.2, second drive motor 2.3, and cutting head 2.4.

[0042] Two rollers 2.2 are mounted on the outside of the housing 2.1, and the second drive motor 2.3 is integrated into the housing 2.1 and connected to the cutting head 2.4. The housing 2.1 is supported by four support rods 3.3 and two rollers 2.2.

[0043] The feed system 3 is divided into two parts: radial feed and circumferential feed. The radial feed part includes a base 3.1, two hydraulic telescopic rods 3.2, and eight support rods 3.3.

[0044] Eight support rods 3.3 and two hydraulic telescopic rods 3.2 are symmetrically installed on the left and right sides of the base 3.1. The support rods 3.3 are connected to the housing 2.1 to form two sets of symmetrical parallel double crank mechanisms. The housing 2.1 serves as the connecting rod, the support rods 3.3 serve as the cranks, and the base 3.1 serves as the frame of the two sets of parallel double crank mechanisms.

[0045] Two hydraulic telescopic rods 3.2 are respectively installed at two opposite corners of two parallel double crank mechanisms as driving devices.

[0046] When both hydraulic telescopic rods 3.2 extend simultaneously, the housing 2.1, which acts as a connecting rod, will move outward in parallel until the rollers 2.2 on the housing 2.1 contact the inner wall of the pipe. At this point, the hydraulic telescopic rods 3.2 stop extending, and the radial feed is completed.

[0047] The circumferential feed section includes a thrust bearing 3.4, a connecting shaft 3.5, and a third drive motor 3.6. The connecting shaft 3.5, used for the transmission between the third drive motor 3.6 and the base 3.1, is installed in the mounting cylinder 1.1, while the third drive motor 3.6 is placed in the connecting cylinder 1.7. Circumferential feed occurs after the radial feed is completed, when the third drive motor 3.6, through the connecting shaft 3.5, drives the entire cutting system 2 to move in a circular motion around the inner wall of the pipe.

[0048] The vibration damping system 4 includes a deep groove ball bearing 4.1 and an adjustable annular damper 4.2. The deep groove ball bearing 4.2 is installed with an interference fit to the lower end of the connecting shaft 3.5. The adjustable annular damper 4.2 is fixed in a groove on the mounting cylinder 1.1 and is connected to the connecting shaft 3.5 through the deep groove ball bearing 4.1.

[0049] The working principle of this invention is as follows: Before cutting, the operator first selects an appropriate cutting feed depth according to the wall thickness of the metal pipe to be cut, adjusts the four rollers 2.2 on the housing of the cutting system 2 so that the radial distance from the outer side of the roller 2.2 to the outer side of the cutting head 2.4 is equal to the cutting feed depth, and adjusts the damping magnitude of the annular damper.

[0050] When cutting begins, the device is lowered to the target cutting position via a rope connected to the three-jaw hook 1.8, and then the device is activated. First, the two first drive motors 1.6 in the support and fixing system 1 operate, driving the upper and lower sets (three in each set) of movable support arms 1.3 to extend outward.

[0051] After the cutting system is firmly fixed to the center of the pipe profile, the cutting system 2 and the feeding system 3 begin to work.

[0052] At this point, the two sets of cutting heads 2.4 begin to rotate, and the two hydraulic telescopic rods 3.2 extend simultaneously until the four rollers 2.2 contact the inner wall of the pipe. The internal pressure of the hydraulic telescopic rods 3.2 rises, and the set radial cutting depth is reached. Circumferential feeding begins, and the third drive motor 3.6 drives the cutting system 2 to rotate half a revolution around the pipe wall. The pipe is then completely cut off, the cutting system 2 stops, the hydraulic telescopic rods 3.2 retract, the movable support arm 1.3 retracts, and the cutting ends.

[0053] This invention provides a method for internal cutting of underground vertical metal pipes, the working process of which can be broken down into the following steps:

[0054] Step 1: The operator determines the optimal radial feed rate based on the wall thickness of the metal pipe to be cut. Different diameter rollers 2.2 are used to ensure the radial distance between the cutting head 2.4 and roller 2.2 equals the optimal radial feed rate. The entire device is then lowered to the designated cutting depth using ropes.

[0055] Step 2: Operation of the support and fixing system 1. The two first drive motors 1.6, through the transmission of bevel gears 1.5 and the rotating disc 1.4, drive the movable extension arms 1.3 to expand outward along the grooves on the mounting cylinder 1.1 to the inner wall of the pipe and fix them in place. At this time, due to the self-locking property of the engagement between the planar Archimedean spiral groove on the rotating disc 1.4 and the thread below the movable extension arms 1.3, and the self-centering property of the three movable extension arms 1.3 extending to the same length, the entire device can be firmly fixed at the center of the pipe profile.

[0056] Step 3: The second drive motor 2.3 drives the cutting head 2.4 to start rotating, and the cutting system 2 begins operation. Next, the feed system 3 starts, and the two hydraulic telescopic rods 3.2 extend, causing the two sets of cutting systems 2 to move parallel to the pipe wall under the action of the parallel double-crank mechanism until the four rollers 2.2 are in full contact with the pipe wall, at which point the extension stops. At this point, the cutting head has reached the preset radial feed amount, and the pipe wall is cut through.

[0057] Step 4: Begin circumferential feeding. The third drive motor 3.6 drives the connecting shaft 3.5 to rotate, the roller 2.2 begins to roll along the inner wall of the pipe, and the cutting head 2.4 begins to cut circumferentially along the pipe. After rotating more than half a turn, the pipe is completely cut off.

[0058] Step 5: The second drive motor 2.3 stops, and the two hydraulic telescopic rods 3.2 shorten, driving the cutting system 2 to retract towards the center via a parallel double crank mechanism. Then, the two first drive motors 1.6 reverse, driving the movable extension arm 1.3 to retract inward along the groove on the mounting cylinder 1.1 through the transmission of the bevel gear 1.5 and the rotating plate 1.4. The inner cutting device and the pipe are completely separated, and the operator retrieves the device using a rope.

[0059] The mechanical structure and working principle of the metal pipe internal cutting device of the present invention have been described in detail above. In summary, the present invention achieves the objectives of preventing resonance, ensuring reliable fixation, stable cutting, and simple operation, and also has strong versatility and high working efficiency.

Claims

1. An internal cutting device suitable for underground vertical metal pipes, comprising a support and fixing system (1), a cutting system (2), a feeding system (3), and a vibration damping system (4), characterized in that: The support and fixing system (1) is divided into upper and lower groups. The support and fixing system (1) includes a mounting cylinder (1.1), a chassis (1.2), a movable support arm (1.3), a rotating plate (1.4), a bevel gear (1.5), a first drive motor (1.6), and a connecting cylinder (1.7). The rotating plate (1.4) is fixed inside the mounting cylinder (1.1) by the base plate (1.2); Three movable support arms (1.3) are installed in the groove on the upper part of the mounting cylinder (1.1), and the lower part has threads that mesh with the flat threads of the rotating disc (1.4); The bevel gear (1.5) is placed on the side of the mounting cylinder (1.1) and meshes with the disc gear surface of the rotating disc (1.4), and the other end is connected to the first drive motor (1.6); The connecting cylinder (1.7) is used to connect the upper and lower sets of support and fixing systems (1); The cutting system (2) includes a housing (2.1), two rollers (2.2), a second drive motor (2.3), and a cutting head (2.4). Two rollers (2.2) are mounted outside the housing (2.1), and a second drive motor (2.3) is integrated inside the housing (2.1) and connected to the cutting head (2.4); The feed system (3) is divided into two parts: radial feed and circumferential feed; The vibration damping system (4) includes a deep groove ball bearing (4.1) and an adjustable annular damper (4.2); the deep groove ball bearing (4.1) is installed with an interference fit at the lower end of the connecting shaft (3.5); the adjustable annular damper (4.2) is fixed in a slot on the mounting cylinder (1.1) and connected to the connecting shaft (3.5) through the deep groove ball bearing (4.1); One side of the rotating disc (1.4) is a disc-shaped gear, and the other side is a flat thread; The radial feed section includes a base (3.1), two hydraulic telescopic rods (3.2), and eight support rods (3.3). The eight support rods (3.3) and the two hydraulic telescopic rods (3.2) are symmetrically installed on the left and right sides of the base (3.1). The support rods (3.3) are connected to the housing (2.1) to form two sets of symmetrical parallel double-crank mechanisms. The housing (2.1) serves as the connecting rod, the support rods (3.3) serve as the cranks, and the base (3.1) simultaneously acts as the frame of the two sets of parallel double-crank mechanisms. The two hydraulic telescopic rods (3.2) are respectively installed on two opposite corners of the two parallel double-crank mechanisms as driving devices. The circumferential feed section includes a thrust bearing (3.4), a connecting shaft (3.5), and a third drive motor (3.6); the connecting shaft (3.5) is used for the transmission between the third drive motor (3.6) and the base (3.1), and is installed in the mounting cylinder (1.1); the third drive motor (3.6) is placed in the connecting cylinder (1.7); The circumferential feed is performed after the radial feed is completed. The third drive motor (3.6) drives the entire cutting system (2) to make a circular motion around the inner wall of the pipe through the connecting shaft (3.5).

2. The internal cutting device for underground vertical metal pipes according to claim 1, characterized in that: The housing (2.1) is supported by four support rods (3.3) and two rollers (2.2).

3. The method for internal cutting of underground vertical metal pipes using the internal cutting device applicable to underground vertical metal pipes according to claim 1, characterized in that: Step 1: Determine the optimal radial feed rate based on the wall thickness of the metal pipe to be cut; replace the rollers (2.2) with rollers of different diameters so that the radial distance between the cutting head (2.4) and the rollers (2.2) is equal to the radial feed rate; then lower the entire device to the specified cutting depth using a rope. Step 2, the support and fixing system (1) operates; the two first drive motors (1.6) drive the movable extension arm (1.3) to expand outward along the groove on the mounting cylinder (1.1) to the inner wall of the pipe and fix it through the transmission of the bevel gear (1.5) and the rotating plate (1.4); by utilizing the self-locking property of the engagement between the flat Archimedean spiral groove on the rotating plate (1.4) and the thread below the movable extension arm (1.3), the entire device is firmly fixed to the center of the pipe profile; Step 3: The second drive motor (2.3) drives the cutting head (2.4) to start rotating, and the cutting system (2) starts to run; then the feeding system (3) starts, and the two hydraulic telescopic rods (3.2) extend, so that the two sets of cutting systems (2) move parallel to the pipe wall under the action of the parallel double crank mechanism until the four rollers (2.2) are in full contact with the pipe wall and then the extension stops. Step 4: Begin circumferential feeding. The third drive motor (3.6) drives the connecting shaft (3.5) to rotate, and the roller (2.2) begins to roll along the inner wall of the pipe. The cutting head (2.4) begins to cut circumferentially along the pipe. After rotating more than half a turn, the pipe is completely cut off. Step 5: The second drive motor (2.3) stops, and the two hydraulic telescopic rods (3.2) shorten, driving the cutting system (2) to retract towards the center through the parallel double crank mechanism; then the two first drive motors (1.6) reverse, driving the movable extension arm (1.3) to retract inward along the groove on the mounting cylinder (1.1) through the transmission of the bevel gear (1.5) and the rotating plate (1.4), completely separating the inner cutting device and the pipe, and then retracting the device through the rope.

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