Pipeline extrusion cold connection method
By processing steps and joint gullets at both ends of the pressure pipeline, and using connecting equipment for extrusion and cold connection, the safety problem of manual entry into the pipeline during the pipeline welding process is solved, and efficient and reliable pipeline connections are achieved.
Patent Information
- Application Number
- CN202411410883.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-10
- Publication Date
- 2025-01-21
AI Technical Summary
In the prior art, the welding process of pressure pipelines requires manual entry into the pipeline for welding, which is very labor-intensive and unsafe.
The pipe extrusion cold-joining method is used to realize the connection of pipelines by processing steps and coupling gullets at both ends of the pipeline, and using connecting equipment to expand the connecting pipe to integrate the pipe steps and coupling ridges.
It reduces the welding risk for operators, simplifies the operating process, improves connection efficiency, achieves better sealing effect under internal pressure, and improves the reliability and sealing performance of pipeline connections.
Smart Images
Figure CN119327993A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of pipeline connection, in particular to a pipeline extrusion cold connection method. Background Art
[0002] In traditional pipeline connection methods, welding, threaded connection or flange connection are usually used. However, these methods have some limitations and shortcomings. Although welding has high connection strength, it is complicated to operate and requires professional welding equipment and technicians, and has certain requirements on the pipe material. Although threaded connection and flange connection are easy to install, they have poor sealing performance, are prone to leakage, and are prone to loosening or falling off under high pressure conditions.
[0003] In the welding process of some pressure pipes, not only the outer cylindrical surface needs to be welded, but also the inner side of the pipe needs to be welded. When some pressure pipes that are only wide enough for one person to lie sideways are in a closed environment, the internal welding method is very detrimental to the processing and personal safety of the operating employees during the butt welding of such pipes.
[0004] In order to solve the internal welding problem of small and medium-sized pressure pipelines, a pipeline extrusion cold connection method is needed. This method processes steps and coupling grooves at both ends of the pipeline, and then expands the connecting pipe through the connecting equipment to become one with the pipeline steps and coupling grooves to achieve the connection of the pipeline. The material of the connecting pipe is ductile metal. Compared with the traditional method, the pipeline extrusion cold connection method has the advantages of reliable connection, good sealing performance and the ability to adapt to bending and deformation at a certain angle. Summary of the invention
[0005] The main purpose of the present invention is to provide a pipeline extrusion cold connection method, which solves the problem that pressure pipelines need to be manually entered for internal welding, which is labor-intensive and unsafe.
[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a pipeline extrusion cold connection method, the method comprising: S1. Process the pipe steps and the combined tooth grooves at both ends of the pipe; S2. Pickling the pipe steps and the positions of the joint tooth grooves; S3, placing the processed pipe into the connecting device; S4. Insert a connecting pipe into the joint of the two pipes; S5. Start the connection device to expand the connection pipe and integrate it with the pipe step and the coupling tooth groove; S6. The connecting device moves the butted pipe forward for a certain distance; S7. Repeat steps S1-S6 until the total length of the pipeline reaches the design requirement.
[0007] In the preferred embodiment, in step S5, the connecting pipe is made of a stainless steel pipe; The connecting pipe undergoes two expansions.
[0008] In a preferred embodiment, the expansion pressure of the connecting device is greater than the yield stress of the connecting pipe.
[0009] In a preferred embodiment, the wall thickness of the pipe is 0.5-2 cm, and the preferred thickness is 0.8-1.5 cm.
[0010] In the preferred embodiment, the connecting device includes a base, a hydraulic assembly is provided on the base, a feeding assembly is provided above the hydraulic assembly, a rotatable expansion tube assembly is provided on one side of the feeding assembly, a guide assembly is provided on the other side of the feeding assembly, and a slidable expansion sleeve assembly is provided on the guide assembly.
[0011] In the preferred embodiment, the guide assembly includes a guide frame, on which guide vertical plates are symmetrically arranged, on which guide vertical plates are provided guide rails, and on which a plurality of slidable guide frames are provided; A lifting guide wheel is provided under the guide frame, and the guide wheel is used to convey the pipeline. The expansion sleeve assembly is arranged on the guide rail; The expansion sleeve assembly includes an expansion sleeve slide plate, which is slidably connected to the guide slide rail. An expansion sleeve shell is provided above the expansion sleeve slide plate, and a limit sleeve is provided inside the expansion sleeve shell. The limit sleeve is in a penetrating cylindrical shape, and the pipeline and the limit sleeve are coaxially arranged.
[0012] In the preferred embodiment, the hydraulic assembly includes a hydraulic frame, a hydraulic oil tank is provided inside the hydraulic frame, a hydraulic pump is provided on one side of the hydraulic oil tank, and the hydraulic pump is used to provide the tube expansion assembly with tube expansion power; The feeding assembly includes a feeding frame, which is arranged above the hydraulic frame, a feeding top plate is arranged on the top of the feeding frame, guide columns are arranged between the two sides of the feeding top plate and the hydraulic frame, a rotatable threaded shaft is arranged between the guide columns, and a clamping hand wheel is arranged on the top of the threaded shaft; A plurality of clamping support plates are provided on one side of the threaded shaft, preferably two clamping support plates, the clamping support plates are threadedly connected to the threaded shaft, and both ends of the clamping support plates are slidably connected to the guide column; Tensioning plates are provided at both ends of the clamping plates, chain plates are provided between the tensioning plates, a plurality of clamping blocks are provided on the chain plates, clamping grooves are provided on the clamping blocks, the material of the clamping blocks is hard rubber, and a limiting roller is also provided on one side of the tensioning plate.
[0013] In a preferred embodiment, the tube expansion assembly includes a rotating base, a rotating motor is provided at the bottom of the rotating base, and the rotating motor is used to control the rotation angle of the rotating base; An expansion tube vertical plate is arranged above the rotating base, a forward guide rail is arranged on one side of the expansion tube vertical plate, a slidable forward slide plate is arranged on the forward guide rail, a guide seat is arranged on one side of the forward slide plate, an extended expansion tube guide rod is arranged on one side of the guide seat, an inner shaft support plate is arranged on the other side of the guide seat, a forward slide block is arranged between the inner shaft support plate and the forward slide plate, and a forward cylinder is arranged between the inner shaft support plate and the guide seat; An expansion tube inner shaft is also provided on one side of the inner shaft support plate, the expansion tube inner shaft penetrates the expansion tube guide rod, the expansion tube inner shaft and the expansion tube guide rod are coaxially arranged, and a stepper motor is provided at the tail end of the expansion tube inner shaft, and the stepper motor is used to control the rotation angle of the expansion tube inner shaft; A guide motor is also arranged below the forward sliding plate, and the guide motor controls the rotation of the ball screw to move the forward sliding plate forward.
[0014] In the preferred embodiment, a sleeve step is provided at the top of the expansion tube guide rod, a plurality of retractable push rods are provided at the sleeve step, and a push electric cylinder is provided inside the sleeve step, and the push electric cylinder is used to drive the push rod to retract; The top end of the inner expansion shaft is provided with a plurality of retractable expansion petals, the interior of the inner expansion shaft is provided with a pressurizing channel, and the tail end of the expansion petals is connected with the pressurizing channel.
[0015] In the preferred embodiment, the expansion tube petals are evenly distributed on the outer circle of the expansion tube inner shaft, and the interval angle of the expansion tube petals is 72 degrees; The single rotation angle of the stepper motor is 36 degrees. Preferably, the stepper motor swings back and forth.
[0016] The present invention provides a pipeline extrusion cold connection method, which has the following beneficial effects: 1. This pipeline extrusion cold connection method optimizes the material of the connecting pipe and adopts an extrusion cold connection method without a heat source, which reduces the welding processing risk of operators. The improved connection equipment structure design simplifies the operation process and improves the connection efficiency; 2. The pipes connected by this method, the connectors and the pipes are extruded and have a self-sealing function, which can achieve a better sealing effect under internal pressure, thereby improving the reliability and sealing performance of the pipe connection. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: Figure 1 is an isometric view of the connection device of the present invention; Figure 2 It is the axial side of the connection device of the present invention for preparing the expansion tube; Figure 3 is a cross-sectional view of a connection device of the present invention; Figure 4 is a top view of the connection device of the present invention; Figure 5It is a partial view of the feeding assembly of the present invention; Figure 6 is an isometric view of the feed assembly of the present invention; Figure 7 is a front view of the feeding assembly of the present invention; Figure 8 is a cross-sectional view of the expansion sleeve assembly of the present invention; Fig. 9 is an axonometric view of the pipeline of the present invention; Fig.10 is an axonometric view of the expanded tube petal of the present invention; Fig.11 is an axial view of the expanded tube petals of the present invention being opened; Fig.12 is a cross-sectional view of the inner shaft of the expansion tube of the present invention; Fig.13 is a cross-sectional view of the expansion tube assembly of the present invention; Fig.14 It is a cross-sectional view of the pipeline connection of the present invention.
[0018] In the figure: base 1; guide assembly 2; guide frame 201; guide vertical plate 202; guide slide rail 203; guide frame 204; guide wheel 205; hydraulic assembly 3; hydraulic frame 301; hydraulic oil tank 302; hydraulic pump 303; feeding assembly 4; feeding frame 401; feeding top plate 402; clamping support plate 403; clamping hand wheel 404; tensioning support plate 405; clamping block 406; clamping groove 407; guide column 408; limit roller 409; threaded shaft 410; expansion tube assembly 5; rotating base 501; expansion tube vertical plate 502; forward movement Guide rail 503; forward slide plate 504; guide seat 505; expansion tube guide rod 506; expansion tube inner shaft 507; inner shaft support plate 508; sleeve step 509; expansion tube petal 510; pressurized channel 511; push rod 512; push electric cylinder 513; stepper motor 514; forward slide block 515; forward cylinder 516; rotating motor 517; guide motor 518; expansion sleeve assembly 6; expansion sleeve housing 601; limit sleeve 602; expansion sleeve slide plate 603; pipeline 7; pipeline step 701; coupling tooth groove 702; connecting pipe 703; connecting device 8. DETAILED DESCRIPTION
[0019] Example 1 like Figure 1-14 As shown, a pipe extrusion cold connection method, the method comprising: S1, processing the pipe steps 701 and the coupling tooth grooves 702 at both ends of the pipe 7; S2, pickling or cleaning the position of the pipeline step 701 and the joint tooth groove 702 to completely expose the surface of the steel pipe; S3, such as Figure 4As shown, the first section of the pipe 7 is transported to one side of the connecting device 8 through the previous process, and the pipe 7 is clamped in the feeding assembly 4 and transported forward, and one end of the first section of the pipe 7 enters the limiting sleeve 602 of the expansion sleeve assembly 6, and the limiting sleeve 602 is made of titanium alloy or high carbon steel; After the first pipe section 7 is conveyed, the second pipe section 7 continues to be conveyed. When the second pipe section 7 is conveyed forward, the front end of the second pipe section 7 will abut against the first pipe section 7. The feeding assembly 4 places the joint of the two pipe sections 7 in the limiting sleeve 602 according to the preset parameters. S4, after the second section of the pipe 7 is delivered, the rotating motor 517 in the expansion assembly 5 rotates the rotating base 501, and the expansion guide rod 506 above the rotating base 501 is coaxial with the center of the pipe 7. The operator sleeves the connecting pipe 703 on the shaft sleeve step 509, which can also be completed by a manipulator to achieve fully automated operation. After the sleeve is completed, the guide motor 518 drives the ball screw to move the forward slide 504 forward; The expansion guide rod 506 moves with the connecting pipe 703 in front of it toward the joint of the pipe 7, and stops moving forward when it moves to a preset position in front of the joint. At this time, the forward cylinder 516 pulls the inner shaft support plate 508 forward, and the expansion inner shaft 507 extends out of the expansion guide rod 506. The center position of the front-to-back length of the extended expansion petal 510 is facing the joint of the pipe 7. Here, the outer circumference of the expansion guide rod 506 can be evenly distributed with a plurality of outwardly rotatable balls, so as to make it easier for the expansion guide rod 506 to extend into the pipe 7; S5, the push electric cylinder 513 drives the push rod 512 to push the connecting tube 703 to the pre-designed position, so that the connecting tube 703 is facing the pipeline step 701. After the push is completed, the push rod 512 retracts to be flush with the shaft sleeve step 509, and the hydraulic pump 303 is started to pressurize the pressurized channel 511, so that the expansion petals 510 open outward, and the squeezed part of the connecting tube 703 fits with the pipeline 7, and part of the connecting tube 703 is squeezed into the combination tooth groove 702 and tightly combined with the pipeline 7, and the shaping is fixed for a period of time; After forming, the hydraulic pump 303 slightly reduces the pressure to separate the expansion flap 510 from the connecting tube 703, and the stepper motor 514 rotates 36 degrees. The above steps are repeated to expand the connecting tube 703 once more to achieve a degree of complete and close fit with the pipeline 7.
[0020] S6. After the connection is completed, the stepper motor 514 rotates back to the original angle, the hydraulic pump 303 retracts the expansion flap 510, the forward cylinder 516 shrinks the expansion inner shaft 507, and the guide motor 518 pulls the front expansion guide rod 506 out of the pipe 7. After the expansion assembly 5 returns to its original position, the motor 517 is rotated to return the expansion assembly 5 to a position perpendicular to the pipe 7. The next section of the pipe 7 is continuously conveyed forward by the feeding assembly 4 to abut against the previously connected section of the pipe 7, and the above steps are repeated. S7. Repeat steps S1-S6 until the total length of the pipeline reaches the design requirement.
[0021] In the preferred embodiment, in step S5, the connecting tube 703 is made of a stainless steel tube; The connecting pipe 703 undergoes two expansions.
[0022] In a preferred embodiment, the expansion pressure of the connecting device 8 is greater than the yield stress of the connecting pipe 703 .
[0023] In a preferred embodiment, the wall thickness of the pipe 7 is 0.5-2 cm, and the preferred thickness is 0.8-1.5 cm.
[0024] In the preferred embodiment, the connecting device 8 includes a base 1, a hydraulic component 3 is provided on the base 1, a feeding component 4 is provided above the hydraulic component 3, a rotatable expansion tube component 5 is provided on one side of the feeding component 4, a guide component 2 is provided on the other side of the feeding component 4, and the guide component 2 is provided with a slidable expansion sleeve component 6.
[0025] In the preferred embodiment, the guide assembly 2 includes a guide frame 201, on which guide vertical plates 202 are symmetrically arranged, on which guide vertical plates 202 are arranged guide rails 203, and on which guide vertical frames 204 are arranged which can slide. A guide wheel 205 that can be raised and lowered is provided below the guide frame 204. The guide wheel 205 is used to transport the pipe 7. The expansion sleeve assembly 6 is arranged on the guide rail 203. The guide frame 204 is mainly used to prevent the pipeline from being deflected when being transported outward. The guide frame 204 is provided with a plurality of threaded holes for installing guide plates of different pipe diameters. The guide plate is a steel plate with holes.
[0026] The expansion sleeve assembly 6 includes an expansion sleeve slide plate 603, which is slidably connected to the guide rail 203, an expansion sleeve shell is provided above the expansion sleeve slide plate 603, and a limiting sleeve 602 is provided inside the expansion sleeve shell 601. The limiting sleeve 602 is in a penetrating cylindrical shape, and the pipeline 7 is coaxially arranged with the limiting sleeve 602; The material of the limit sleeve 602 needs to be a super-hard alloy, such as titanium alloy or tungsten steel, to prevent cracking during tube expansion.
[0027] In the preferred embodiment, the hydraulic assembly 3 includes a hydraulic frame 301, a hydraulic oil tank 302 is provided inside the hydraulic frame 301, a hydraulic pump 303 is provided on one side of the hydraulic oil tank 302, and the hydraulic pump 303 is used to provide expansion power to the expansion assembly 5. The hydraulic assembly 3 can be replaced by an existing hydraulic station with a higher pressure; The feeding assembly 4 includes a feeding frame 401, which is arranged above the hydraulic frame 301. A feeding top plate 402 is provided on the top of the feeding frame 401. Guide columns 408 are provided between the two sides of the feeding top plate 402 and the hydraulic frame 301. A rotatable threaded shaft 410 is provided between the guide columns 408. A clamping hand wheel 404 is provided on the top of the threaded shaft 410. A plurality of clamping support plates 403 are provided on one side of the threaded shaft 410, preferably two clamping support plates 403, the clamping support plates 403 are threadedly connected to the threaded shaft 410, and both ends of the clamping support plates 403 are slidably connected to the guide pillars 408; Tensioning plates 405 are provided at both ends of the clamping plate 403, and chain plates are provided between the tensioning plates 405. A plurality of clamping blocks 406 are provided on the chain plates, and clamping grooves 407 are provided on the clamping blocks 406. The material of the clamping blocks 406 is hard rubber, and a limiting roller 409 is also provided on one side of the tensioning plate 405; The feeding assembly 4 is divided into two sets of upper and lower clamping chain plate conveyor lines. A clamping block 406 is provided on the chain plate line. The clamping block 406 is connected to the chain plate by bolts. When the upper and lower clamping conveyor lines are processing steel pipes of the same diameter, there is no need to repeat the adjustment after the adjustment is completed.
[0028] In the preferred embodiment, the expansion tube assembly 5 includes a rotating base 501, and a rotating motor 517 is provided at the bottom of the rotating base 501. The rotating motor 517 is used to control the rotation angle of the rotating base 501. An expansion tube stand 502 is provided above the rotating base 501, a forward guide rail 503 is provided on one side of the expansion tube stand 502, a slidable forward slide 504 is provided on the forward guide rail 503, a guide seat 505 is provided on one side of the forward slide 504, an extended expansion tube guide rod 506 is provided on one side of the guide seat 505, an inner shaft support plate 508 is provided on the other side of the guide seat 505, a forward slide block 515 is provided between the inner shaft support plate 508 and the forward slide 504, and a forward cylinder 516 is provided between the inner shaft support plate 508 and the guide seat 505; An expansion tube inner shaft 507 is also provided on one side of the inner shaft support plate 508. The expansion tube inner shaft 507 penetrates the expansion tube guide rod 506. The expansion tube inner shaft 507 and the expansion tube guide rod 506 are coaxially arranged. A stepper motor 514 is provided at the tail end of the expansion tube inner shaft 507. The stepper motor 514 is used to control the rotation angle of the expansion tube inner shaft 507. A guide motor 518 is further provided below the forward sliding plate 504 , and the guide motor 518 controls the ball screw to rotate so that the forward sliding plate 504 moves forward.
[0029] In the preferred embodiment, a sleeve step 509 is provided at the top of the expansion tube guide rod 506, a plurality of retractable push rods 512 are provided at the sleeve step 509, and a push electric cylinder 513 is provided inside the sleeve step 509, and the push electric cylinder 513 is used to drive the push rods 512 to retract; A plurality of retractable expansion petals 510 are disposed at the top end of the expansion inner shaft 507 . A pressurizing channel 511 is disposed inside the expansion inner shaft 507 . The tail ends of the expansion petals 510 are communicated with the pressurizing channel 511 .
[0030] In the preferred embodiment, the expansion tube petals 510 are evenly distributed on the outer circle of the expansion tube inner shaft 507, and the interval angle of the expansion tube petals 510 is 72 degrees; The single rotation angle of the stepper motor 514 is 36 degrees. Preferably, the stepper motor 514 swings back and forth. The above embodiments are only preferred technical solutions of the present invention and should not be regarded as limiting the present invention. The protection scope of the present invention shall be the technical solutions recorded in the claims, including equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.
Claims
1. A pipe extrusion cold connection method, characterized by: The method includes: S1, processing the two ends of the pipe (7) into pipe steps (701) and coupling grooves (702); S2, pickling the position of the pipeline step (701) and the joint tooth groove (702); S3, placing the processed pipe (7) into the connecting device (8); S4, inserting a connecting pipe (703) into the joint between the two pipe sections (7); S5, starting the connection device (8) to expand the connection pipe (703) and integrate it with the pipeline step (701) and the coupling groove (702); S6, the connecting device (8) moves the butted pipe (7) forward a certain distance; S7. Repeat steps S1-S6 until the total length of the pipeline reaches the design requirement.
2. According to claim 1, a pipe extrusion cold joining method is characterized by: In step S5, the material of the connecting pipe (703) is a stainless steel pipe; The connecting pipe (703) undergoes two expansions.
3. According to claim 1, a pipe extrusion cold joining method is characterized by: The expansion pressure of the connecting device (8) is greater than the yield stress of the connecting pipe (703).
4. According to claim 1, a pipe extrusion cold joining method is characterized by: The wall thickness of the pipe (7) is 0.5-2 cm, preferably 0.8-1.5 cm.
5. According to claim 1, a pipe extrusion cold joining method is characterized by: The connection device (8) comprises a base (1), a hydraulic assembly (3) is provided on the base (1), a feeding assembly (4) is provided above the hydraulic assembly (3), a rotatable expansion tube assembly (5) is provided on one side of the feeding assembly (4), a guide assembly (2) is provided on the other side of the feeding assembly (4), and a slidable expansion sleeve assembly (6) is provided on the guide assembly (2).
6. A pipe extrusion cold joining method according to claim 5, characterized in that: The guide assembly (2) comprises a guide frame (201), guide vertical plates (202) are symmetrically arranged on the guide frame (201), guide slide rails (203) are arranged on the guide vertical plates (202), and a plurality of slidable guide frames (204) are arranged on the guide frame (202); A guide wheel (205) that can be raised and lowered is provided below the guide frame (204), and the guide wheel (205) is used to convey the pipeline (7). The expansion sleeve assembly (6) is arranged on the guide slide rail (203); The expansion sleeve assembly (6) comprises an expansion sleeve slide plate (603), the expansion sleeve slide plate (603) is slidably connected to the guide slide rail (203), an expansion sleeve shell is provided above the expansion sleeve slide plate (603), a limiting sleeve (602) is provided inside the expansion sleeve shell (601), the limiting sleeve (602) is in the shape of a penetrating cylinder, and the pipeline (7) and the limiting sleeve (602) are coaxially arranged.
7. A pipe extrusion cold joining method according to claim 5, characterized in that: The hydraulic assembly (3) comprises a hydraulic frame (301), a hydraulic oil tank (302) is provided inside the hydraulic frame (301), a hydraulic pump (303) is provided on one side of the hydraulic oil tank (302), and the hydraulic pump (303) is used to provide tube expansion power to the tube expansion assembly (5); The feeding assembly (4) comprises a feeding frame (401), the feeding frame (401) is arranged above the hydraulic frame (301), a feeding top plate (402) is provided on the top of the feeding frame (401), guide columns (408) are provided between the two sides of the feeding top plate (402) and the hydraulic frame (301), a rotatable threaded shaft (410) is provided between the guide columns (408), and a clamping hand wheel (404) is provided on the top of the threaded shaft (410); A plurality of clamping support plates (403), preferably two clamping support plates (403), are provided on one side of the threaded shaft (410); the clamping support plates (403) are threadedly connected to the threaded shaft (410); and both ends of the clamping support plates (403) are slidably connected to the guide pillars (408); Tensioning support plates (405) are provided at both ends of the clamping support plate (403), a chain plate is provided between the tensioning support plates (405), a plurality of clamping blocks (406) are provided on the chain plate, a clamping groove (407) is provided on the clamping block (406), the material of the clamping block (406) is hard rubber, and a limiting roller (409) is also provided on one side of the tensioning support plate (405).
8. The pipe extrusion cold joining method according to claim 5, characterized in that: The tube expansion assembly (5) comprises a rotating base (501), a rotating motor (517) is provided at the bottom of the rotating base (501), and the rotating motor (517) is used to control the rotation angle of the rotating base (501); A tube expansion vertical plate (502) is provided above the rotating base (501), a forward guide rail (503) is provided on one side of the tube expansion vertical plate (502), a slidable forward slide plate (504) is provided on the forward guide rail (503), a guide seat (505) is provided on one side of the forward slide plate (504), an extended tube expansion guide rod (506) is provided on one side of the guide seat (505), an inner shaft support plate (508) is provided on the other side of the guide seat (505), a forward slide block (515) is provided between the inner shaft support plate (508) and the forward slide plate (504), and a forward cylinder (516) is provided between the inner shaft support plate (508) and the guide seat (505); An expansion tube inner shaft (507) is also provided on one side of the inner shaft support plate (508). The expansion tube inner shaft (507) penetrates the expansion tube guide rod (506). The expansion tube inner shaft (507) and the expansion tube guide rod (506) are coaxially arranged. A stepping motor (514) is provided at the tail end of the expansion tube inner shaft (507). The stepping motor (514) is used to control the rotation angle of the expansion tube inner shaft (507). A guide motor (518) is also provided below the forward sliding plate (504), and the guide motor (518) controls the ball screw to rotate so that the forward sliding plate (504) moves forward.
9. A pipe extrusion cold joining method according to claim 8, characterized in that: A shaft sleeve step (509) is provided at the top end of the expansion tube guide rod (506), a plurality of retractable push rods (512) are provided at the shaft sleeve step (509), a push electric cylinder (513) is provided inside the shaft sleeve step (509), and the push electric cylinder (513) is used to drive the push rods (512) to retract; A plurality of retractable tube expansion petals (510) are provided at the top end of the tube expansion inner shaft (507), a pressurizing channel (511) is provided inside the tube expansion inner shaft (507), and the tail ends of the tube expansion petals (510) are in communication with the pressurizing channel (511).
10. A pipe extrusion cold joining method according to claim 9, characterized in that: The expansion tube petals (510) are evenly distributed on the outer circle of the expansion tube inner shaft (507), and the interval angle of the expansion tube petals (510) is 72 degrees; The single rotation angle of the stepper motor (514) is 36 degrees. Preferably, the stepper motor (514) swings back and forth.