A plastic pipe opening post-processing expansion device

Abstract

The invention discloses a expanding device for post-processing a plastic pipe orifice in the field of plastic pipe forming technology. The device comprises a pipe and a workbench, wherein a plurality of support rods are fixedly connected to the top of the workbench along the axial direction, and kits are arranged at positions near the left and right sides of the workbench, and a driving group is arranged on one side of the two kits; the forming part is directly inserted into the pipe through relative movement between the forming part and the pipe, and the pipe can be expanded into a desired shape at one time through the restriction of the kit during insertion, without the need to expand first and then shrink, thereby improving the uniformity and stability of the expansion, avoiding deformation during the expansion, and thus meeting the installation requirements; when the pipe is removed, the forming part is present at the expanding position of the pipe, and this method can also facilitate the feeding of the forming part and the pipe, prolong a certain contact time, improve the efficiency of forming, reduce the cooling time of the pipe on the workbench, and is conducive to large-scale production.

Description

Technical Field

[0001] The invention relates to the technical field of plastic pipe forming, in particular to a pipe opening expansion device for post-processing of a plastic pipe. Background Art

[0002] In order to meet the needs of installation, plastic pipes often need to be expanded after production; traditional expansion shaping is usually single-sided shaping, but in the actual installation needs of actual pipelines, in order to ensure the sealing of the pipe connection and facilitate plug-in, the expanded end often requires bilateral shaping, such as Figure 1 As shown, a is the finished product, but during processing, the pipe needs to be expanded into b first and then from b to c. The process is cumbersome. The expansion of this type of pipe requires a multilateral mold to be finalized, which will lead to great difficulty in blanking. At the same time, in order to ensure the uniformity and stability of the expansion, the pipe mouth is often formed by expanding first and then shrinking; this will lead to low overall efficiency of the expansion work of the pipe mouth.

[0003] Based on this, the present invention designs a plastic pipe orifice post-processing expansion device to solve the above-mentioned problem. Summary of the invention

[0004] The object of the present invention is to provide a plastic pipe orifice post-processing expansion device to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a expanding device for post-processing of plastic pipe orifices, comprising a pipeline and a workbench, a plurality of support rods are fixedly connected to the top of the workbench along the axial direction, a set of kits are arranged on the workbench near the left and right sides, a driving group is arranged on one side of the two sets of kits, and the driving group is used to drive the set of kits to clamp, separate and transport the pipeline to the rear, a conveying rack is arranged behind the two sets of kits, and the two conveying racks are jointly provided with molded parts, and several of the molded parts are distributed along the axis of the conveying rack, and the molded parts are all hollow shells inside, and the two conveying racks are provided with a conveying trough for placing and conveying the molded parts, and a push plate and a molding group are arranged at the rear of the molded parts, and the molding group is used to move the push plate from the rear to the front so as to make several molded parts approach the direction of the pipeline.

[0006] As a further solution of the present invention, the driving group includes a cross bar, which is slidably connected to the workbench, a first cylinder is arranged between the cross bar and the top of the workbench, the first cylinder is fixedly connected to the workbench and its telescopic end is fixedly connected to the side wall of the cross bar, a support rod is slidably connected to the cross bar, a second cylinder is fixedly connected between the cross bar and the support rod, the end of the support rod is slidably connected to the end extending from the side wall of the kit, and a second spring is fixedly connected between the inner wall of the support rod and the kit.

[0007] As a further solution of the present invention, two alignment groups for aligning the pipe opening of the pipeline with the sleeve are arranged between the sleeve and the conveying frame, and the two alignment groups are respectively arranged in front of the two conveying frames;

[0008] The alignment group includes an oblique rod and a sliding member, the oblique rod is slidably connected to a connecting member along the axial direction, a sixth spring is fixedly connected between the connecting member and the oblique rod, a contact piece is rotatably connected to the connecting member, a first torsion spring is sleeved on the rotating shaft of the contact piece, the contact piece can only rotate forward, the sliding member is slidably connected to the inner wall of the sleeve, a first spring is fixedly connected between the sliding member and the sleeve, and a rubber layer is glued to the inner wall of the sliding member;

[0009] The support rod is provided with a locking group, and the locking group is used to lock the sliding member after the sliding member moves relative to the sleeve following the pipeline.

[0010] As a further solution of the present invention, the locking group includes a fixed rod and a first rack rod, the fixed rod is slidably connected to the side wall of the support rod, a third spring is fixedly connected between the fixed rod and the support rod, the end of the fixed rod is rotatably connected to an electrically controlled gear, the electrically controlled gear is controlled by an electrically controlled component to be locked and freely rotated, and the first rack rod is fixed to the inner wall of the sliding part.

[0011] As a further solution of the present invention, the distance between the two conveying grooves is greater than the length of the rear end of the formed piece, the conveying racks are rotatably connected with gears, the rotating shafts of the gears are sleeved with second torsion springs, the two gears are fixedly connected with centering rods, the two centering rods are fixedly connected with centering pieces, the two gears are meshed with second rack rods, the two second rack rods are fixedly connected with adjusting rods, the rear ends of the two adjusting rods are provided with inclined surfaces, the two adjusting rods are slidably connected with notches, the two notches are respectively provided on the two conveying racks, the two adjusting rods are fixedly connected with fourth springs between the two adjusting rods and the conveying racks, and the two adjusting rods are provided with extrusion rods at the rear, and the extrusion rods are used to make the adjusting rods slide along the notches when the forming group is working;

[0012] The two centering pieces can forcibly make the axis of the sleeve coincide with the axis of the molded part when the two sleeves are clamped.

[0013] As a further solution of the present invention, the forming group includes a third cylinder, which is fixedly connected to the workbench, and the telescopic end of the third cylinder is fixedly connected to a push block, which is arranged directly below the push plate, and the extrusion rod is fixedly connected to the left and right sides of the push block.

[0014] As a further solution of the present invention, the push block is slidably connected to the push plate, and a fifth spring is fixedly connected between the push block and the push plate.

[0015] As a further solution of the present invention, a through hole is provided on the rear end of the molded part.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The molded part is directly inserted into the pipe through the relative movement between the molded part and the pipe. During the insertion, the pipe can be expanded into the desired shape at one time through the limitation of the kit without expanding first and then shrinking, thereby improving the uniformity and stability of the expansion, avoiding deformation during expansion, and thus meeting the installation needs. When the pipe is removed, the molded part is in the expanded position of the pipe. This method can also facilitate the feeding of the molded part and the pipe, extend a certain contact time, improve the molding efficiency, reduce the cooling time of the pipe on the workbench, and is conducive to large-scale production.

[0018] By placing the pipe so that its end protrudes backward relative to the kit and then aligning it, it can be ensured that the length of the expanded edge is the same when the molded part moves a fixed distance during the molding work. If the position of the pipe end is not fixed, the expanded length will be different. Too long or too short will affect the sealing during the connection and may produce defective products.

[0019] After adjusting the molded parts through two adjusting rods, the two sets are compulsorily adjusted again based on the two molded parts to ensure concentricity and efficiency during expansion. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the two steps of first expansion and then contraction;

[0021] Figure 2 It is a schematic diagram of the overall structure of the present invention;

[0022] Figure 3 It is a structural schematic diagram of the drive group of the present invention;

[0023] Figure 4 It is a schematic diagram of the positional relationship between the support rod, the second spring and the kit of the present invention;

[0024] Figure 5 It is a schematic diagram of the connection relationship between the sliding member, the kit and the first rack rod of the present invention;

[0025] Figure 6 It is a schematic diagram of the positional relationship between the forming group, the alignment group and the adjusting rod of the present invention;

[0026] Figure 7 It is a schematic diagram of the positional relationship between the adjusting rod, the centering rod and the centering piece of the present invention;

[0027] Figure 8 It is a schematic diagram of the connection relationship between the push plate, the push block and the fifth spring of the present invention;

[0028] Fig. 9 It is a schematic diagram of the positional relationship between the oblique rod, the connecting member and the contact piece of the present invention;

[0029] Fig.10 It is a schematic diagram of the positional relationship between the adjusting rod, the conveying frame and the fourth spring of the present invention;

[0030] Fig.11 It is a schematic diagram of the formed part and the kit after the pipe expansion is completed in the present invention.

[0031] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0032] 1. Pipeline; 2. Workbench; 3. Support rod; 4. Kit; 5. Conveyor rack; 6. Forming part; 7. Conveyor trough; 8. Push plate; 9. Oblique rod; 10. Connector; 11. Contact piece; 12. First torsion spring; 13. Sliding part; 14. First spring; 15. Cross bar; 16. First cylinder; 17. Support rod; 18. Second spring; 19. Fixed rod; 20. Third spring; 21. Electric control gear; 22. First rack rod; 23. Gear; 24. Second torsion spring; 25. Centering rod; 26. Centering piece; 27. Second rack rod; 28. Adjusting rod; 29. ​​Notch; 30. Fourth spring; 31. Extrusion rod; 32. Third cylinder; 33. Push block; 34. Fifth spring; 35. Sixth spring; 36. Second cylinder. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] See also Figure 1-Figure 11The present invention provides a technical solution: a expanding device for post-processing of a plastic pipe orifice, comprising a pipe 1 and a workbench 2, a plurality of support rods 3 being fixedly connected to the top of the workbench 2 along the axial direction, a set 4 being arranged near the left and right sides of the workbench 2, a driving group being arranged on one side of the two sets 4, the driving group being used to drive the set 4 to clamp, separate and convey the pipe 1 to the rear, a conveying rack 5 being arranged at the rear of the two sets 4, a forming part 6 being arranged on the two conveying racks 5 in common, a plurality of forming parts 6 being distributed along the axis of the conveying rack 5, the forming parts 6 being hollow shells inside, a conveying trough 7 for placing and conveying the forming parts 6 being arranged on the two conveying racks 5, a push plate 8 and a forming group being arranged at the rear of the forming parts 6, the forming group being used to move the push plate 8 from the rear to the front so as to make the plurality of forming parts 6 approach the pipe 1.

[0035] The driving group includes a cross bar 15, which is slidably connected to the workbench 2. A first cylinder 16 is arranged between the cross bar 15 and the top of the workbench 2. The first cylinder 16 is fixedly connected to the workbench 2 and its telescopic end is fixedly connected to the side wall of the cross bar 15. A support rod 17 is slidably connected to the cross bar 15. A second cylinder 36 is fixedly connected between the cross bar 15 and the support rod 17. The end of the support rod 17 is slidably connected to the end extending from the side wall of the set 4. A second spring 18 is fixedly connected between the inner wall of the support rod 17 and the set 4.

[0036] Two alignment groups are arranged between the set 4 and the conveying frame 5 for aligning the pipe opening of the pipeline 1 with the set 4, and the two alignment groups are arranged in front of the two conveying frames 5 respectively;

[0037] The alignment group includes an inclined rod 9 and a sliding member 13. The inclined rod 9 is slidably connected to a connecting member 10 along the axial direction. A sixth spring 35 is fixedly connected between the connecting member 10 and the inclined rod 9. A contact piece 11 is rotatably connected to the connecting member 10. A first torsion spring 12 is sleeved on the rotating shaft of the contact piece 11. The contact piece 11 can only rotate forward. The sliding member 13 is slidably connected to the inner wall of the set 4. A first spring 14 is fixedly connected between the sliding member 13 and the set 4. A rubber layer is glued to the inner wall of the sliding member 13.

[0038] A locking group is provided on the support rod 17 , and the locking group is used to lock the sliding member 13 after the sliding member 13 moves relative to the sleeve 4 following the pipeline 1 .

[0039] like Figure 1-Figure 7 as well as Fig. 9 and Fig.11 As shown:

[0040] Before expanding, heat the end of the pipe 1, and then place the pipe 1 on the workbench 2 through a plurality of support rods 3. The expanded end of the pipe 1 needs to be placed backwards, and the end of the pipe 1 needs to be placed slightly behind the two sets 4;

[0041] Clamping and fixing of pipe 1:

[0042] After the placement is completed, the two first cylinders 16 are started, the first cylinders 16 will be shortened and drive the two sets 4 to approach the pipe 1 through the support rod 17, and then the two sets 4 and the sliding member 13 will clamp the pipe 1, and when the two sets 4 are in contact, the support rod 17 and the cross bar 15 continue to move, and the second spring 18 will be gradually compressed, thereby ensuring the clamping effect on the pipe 1;

[0043] Transportation of pipeline 1 and alignment work during transportation:

[0044] The second cylinder 36 is started to push the support rod 17 to slide backward along the cross bar 15, so that the set 4 and the sliding member 13 drive the pipe 1 to move backward. When the pipe 1 moves backward to contact with the contact piece 11, the contact piece 11 will not rotate backward under the restriction of the connecting member 10, but will give the pipe 1 a reverse push when contacting with the pipe 1 (because the port of the pipe 1 needs to be placed at the rear position of the set 4 when placing the pipe 1), so that the pipe 1 drives the sliding member 13 to slide along the inner wall of the set 4 while being clamped by the sliding member 13 and stretch the first spring 14, so that the port of the pipe 1 protruding backward can gradually shrink, until the protruding port of the pipe 1 is completely entered into the set 4, and the port of the pipe 1 will be flush with the port of the set 4. At this time, the locking group will fix the sliding member 13 at this position, so that the pipe 1 and the sliding member 13 will not move (and after the heated pipe 1 contacts with the contact piece 11, the heated pipe 1 will not be deformed, because the deformation of the pipe 1 requires a strong thrust to deform, so it will not be deformed during alignment);

[0045] Then the second cylinder 36 continues to extend, the set 4 will push the contact piece 11 to move backward, and the contact piece 11 will drive the connecting piece 10 to slide backward along the inclined rod 9 and slide to the left and right sides (the trajectory of the inclined rod 9 is inclined), at this time, the contact piece 11 will slide to both sides relative to the side wall of the set 4 and the port of the pipeline 1, when the set 4 pushes the contact piece 11 to move to the limit position, the sixth spring 35 will be compressed to the limit, the contact piece 11 will fit to the front of the conveying frame 5 behind it and will block the front end of the conveying groove 7, at this time, the end of the contact piece 11 is in contact with the set 4, but its end is not on the projection surface of the inner diameter of the set 4, and then the second cylinder 36 stops extending, at this time, the set 4 and the sliding piece 13 and the pipeline 1 will stay here, waiting for the molding work;

[0046] Molding work:

[0047] At this time, the forming group will drive the push plate 8 to move straight forward from the rear. During the movement, the push plate 8 will contact the forming piece 6 at the rear and then push all the forming pieces 6 between the two conveying racks 5 to move forward a certain distance until the second cylinder 36 is extended to the limit, and the end of the forming piece 6 at the front will contact the contact piece 11 in front of the conveying groove 7, but the contact piece 11 is blocked by the end of the kit 4 at this time, so when the forming piece 6 at the front moves to the limit, it can be restricted by the contact piece 11, thereby ensuring that the rear end of the forming piece 6 at the front can move to the front of the conveying groove 7 and be inserted into the pipe 1, thereby ensuring that the forming piece 6 can complete the expansion work of the pipe 1 (such as Fig.11 shown);

[0048] After the expansion is completed, the second cylinder 36 is started to drive the support rod 17 to retreat. At this time, the pipe 1 and the molded part 6 inside the pipe 1 will retreat together. When retreating, the rear end of the molded part 6 inside the conveying groove 7 will move with the pipe 1 from behind the contact piece 11, thereby pushing the contact piece 11 to rotate forward around the rotation axis and compressing the first torsion spring 12, so that the contact piece 11 can make way for the end of the molded part 6 to be separated from the conveying groove 7. After the second cylinder 36 is reset, the first cylinder 16 is started to release the clamping of the set 4 on the pipe 1, so that the expanded pipe 1 and the molded part 6 inside the pipe 1 can be removed together. After removal, the molded part 6 can be directly disassembled or wait for a certain period of time for the pipe 1 to cool before disassembly, and then the push plate 8 is reset;

[0049] The relative movement of the molded part 6 and the pipe 1 allows the molded part 6 to be directly inserted into the pipe 1. During the insertion, the pipe 1 can be expanded into a desired shape at one time by the restriction of the sleeve 4 (by Figure 1 In the middle c shape), there is no need to expand first and then shrink, which improves the uniformity and stability of the expansion, avoids deformation during expansion, and thus meets the installation requirements. When the pipe 1 is removed, the molded part 6 is present at the expansion position of the pipe 1. This method can also facilitate the feeding of the molded part 6 and the pipe 1, extend a certain contact time, improve the molding efficiency, reduce the cooling time of the pipe 1 on the workbench 2, and is conducive to large-scale production;

[0050] After the pipe 1 is removed, new molded parts 6 need to be placed again on the two conveyor racks 5 to facilitate subsequent continuous work;

[0051] By placing the pipe 1 so that its end protrudes backward relative to the kit 4 and then aligning it, it can be ensured that the length of the expanded edge of the molding 6 is the same when the moving distance is fixed during the molding work. If the position of the end of the pipe 1 is not fixed, the expanded length will be different. Too long or too short will affect the sealing during the connection and may produce defective products.

[0052] The locking group includes a fixed rod 19 and a first rack rod 22. The fixed rod 19 is slidably connected to the side wall of the support rod 17. A third spring 20 is fixedly connected between the fixed rod 19 and the support rod 17. The end of the fixed rod 19 is rotatably connected to an electrically controlled gear 21. The electrically controlled gear 21 is controlled by an electrically controlled component to be locked and freely rotated. The first rack rod 22 is fixed to the inner wall of the sliding member 13.

[0053] like Figure 4 and Figure 5 As shown:

[0054] When the set 4 and the sliding member 13 do not clamp the pipe 1, the fixed rod 19 is at a certain distance from the first rack rod 22. When the sliding member 13 clamps the pipe 1, the second spring 18 is compressed to the limit. When the second spring 18 is compressed, the end of the set 4 slides inside the support rod 17, so at this time the distance between the support rod 17 and the first rack rod 22 is shortened. When the electric control gear 21 moves to contact with the first rack rod 22, if the support rod 17 and the set 4 continue to slide relative to each other, the fixed rod 19 will gradually compress the third spring 20, so that the electric control gear 21 can maintain the contact state with the first rack rod 22.

[0055] Then the pipe 1 will be transported backwards, and during the transportation process, the end of the pipe 1 will contact the contact piece 11, so that the pipe 1 and the sliding member 13 move backwards, at this time the first spring 14 is stretched, and the sliding member 13 slides forward and drives the first rack rod 22 to move forward, at this time the first rack rod 22 will mesh with the electric control gear 21 and the electric control gear 21 can rotate freely, when the pipe 1 is transported and stopped, the contact piece 11 is directly in front of the conveying groove 7, at this time the end of the pipe 1 is flush with the kit 4, at this time the electric control component will lock the electric control gear 21, so that it cannot rotate (it can be understood that before the second cylinder 36 is extended to the limit, the electric control gear 21 is in a state of being able to rotate freely, and when it is extended to the limit, the electric control gear 21 is self-locking), so that the electric control gear 21 locks the first rack rod 22, the sliding member 13 and the pipe 1, and then the subsequent molding work is carried out to prevent the pipe 1 from moving when the molding member 6 is inserted into the pipe 1.

[0056] The distance between the two conveying grooves 7 is greater than the length of the rear end of the formed piece 6. The conveying frame 5 is rotatably connected with a gear 23. The rotating shaft of the gear 23 is sleeved with a second torsion spring 24. The two gears 23 are fixedly connected with a centering rod 25. The two centering rods 25 are fixedly connected with a centering piece 26. The two gears 23 are meshed with a second rack rod 27. The two second rack rods 27 are fixedly connected with an adjusting rod 28. The rear ends of the two adjusting rods 28 are provided with an inclined surface. The two adjusting rods 28 are slidably connected with a notch 29. The two notches 29 are respectively provided on the two conveying frames 5. A fourth spring 30 is fixedly connected between the two adjusting rods 28 and the conveying frame 5. An extrusion rod 31 is provided behind the two adjusting rods 28. The extrusion rod 31 is used to make the adjusting rod 28 slide along the notch 29 when the forming group is working.

[0057] The two centering elements 26 can forcibly make the axis of the sleeve 4 coincide with the axis of the molded part 6 when the two sleeves 4 are clamped.

[0058] The forming group includes a third cylinder 32 , which is fixedly connected to the workbench 2 . A push block 33 is fixedly connected to the telescopic end of the third cylinder 32 . The push block 33 is arranged directly below the push plate 8 . The extrusion rod 31 is fixedly connected to the left and right sides of the push block 33 .

[0059] The push block 33 is slidably connected to the push plate 8 , and a fifth spring 34 is fixedly connected between the push block 33 and the push plate 8 .

[0060] like Figure 6-Figure 8 as well as Fig.10 As shown:

[0061] The distance between the two conveying grooves 7 can be set to be greater than the diameter length of the rear end of the molded part 6, which can facilitate the placement of the molded part 6 between the two conveying grooves 7. In order to facilitate not affecting the concentricity with the pipeline 1 after the placement is completed, measures are provided to avoid the misalignment of the two:

[0062] When the forming group needs to drive the push plate 8 to move forward, the third cylinder 32 shortens and drives the push block 33 to slide forward along the workbench 2, and the push block 33 drives the push plate 8 to move forward until the push plate 8 contacts the forming piece 6 at the rear, and then pushes the forming piece 6 at the front to move forward. Moreover, before the forming piece 6 moves, the extrusion rod 31 moves forward first and contacts the inclined surface of the adjustment rod 28, thereby causing the adjustment rod 28 to move inward along the notch 29, and the side of the adjustment rod 28 located in the notch 29 does not exceed the notch 29 when not squeezed by the extrusion rod 31, that is, the adjustment rod 28 cannot contact the two sides of the end of the forming piece 6 before it moves.

[0063] When the adjusting rod 28 is squeezed by the squeezing rod 31 and slides along the notch 29, the fourth spring 30 will be stretched, and the adjusting rod 28 will slide from both sides into the conveying trough 7 until the two adjusting rods 28 contact the two sides of the forming part 6 respectively, and the center line of the forming part 6 will be in the middle of the two conveying racks 5, so that the forming part 6 is placed and before it contacts the pipe 1. When the adjusting rod 28 moves into the conveying trough 7, the two second rack rods 27 will mesh with the gear 23 and drive the gear 23 and the two centering rods 25 to rotate toward the middle until the centering piece 26 clamps the two The degree of the set 4 is that the two sets 4 are clamped from both sides by two centering pieces 26, which can ensure that the center lines of the two sets 4 are at a position that coincides with the center line of the molded piece 6, thereby ensuring the concentricity between the two sets. When the two sets 4 are clamped, the two second springs 18 may be compressed to different degrees at the same time, resulting in asymmetric concentricity, which will affect the subsequent expansion of the molded piece 6. After the molded piece 6 is adjusted by the two adjustment rods 28, the two sets 4 are compulsorily adjusted again based on the two molded pieces 6, thereby ensuring concentricity, thereby ensuring the efficiency of the expansion;

[0064] When the extrusion rod 31 moves following the push block 33, the extrusion rod 31 moves along the side wall of the adjustment rod 28, thereby maintaining the extrusion of the adjustment rod 28, ensuring that the molded part 6 does not deviate when approaching the pipe 1;

[0065] The fifth spring 34 can provide a certain buffering effect, but does not hinder the pushing effect on the molded part 6 .

[0066] A through hole is provided on the rear end of the forming piece 6. Through the through hole, it is convenient for the forming piece to separate from the pipeline 1 after the expansion is completed.

[0067] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A device for expanding the orifice of a plastic pipe for post-processing, comprising a pipe (1) and a workbench (2), wherein a plurality of support rods (3) are fixedly connected to the top of the workbench (2) along the axial direction, and characterized in that: The workbench (2) is provided with a kit (4) at a position near the left and right sides, and a driving group is provided on one side of the two kits (4). The driving group is used to drive the kit (4) to clamp and separate the pipeline (1) and to transport the pipeline (1) to the rear. A conveying rack (5) is provided at the rear of the two kits (4). The two conveying racks (5) are provided with a molded part (6) in common. Several molded parts (6) are distributed along the axis of the conveying rack (5). The molded parts (6) are all hollow shells. The two conveying racks (5) are provided with a conveying trough (7) for placing the molded parts (6) for conveying. A push plate (8) and a molding group are provided at the rear of the molded parts (6). The molding group is used to move the push plate (8) from the rear to the front so as to move several molded parts (6) closer to the pipeline (1); The driving group comprises a cross bar (15), the cross bar (15) being slidably connected to the workbench (2), a first cylinder (16) being arranged between the cross bar (15) and the top of the workbench (2), the first cylinder (16) being fixedly connected to the workbench (2) and having a telescopic end fixedly connected to a side wall of the cross bar (15), a support rod (17) being slidably connected to the cross bar (15), a second cylinder (36) being fixedly connected between the cross bar (15) and the support rod (17), an end of the support rod (17) being slidably connected to an end extending from a side wall of the kit (4), and a second spring (18) being fixedly connected between an inner wall of the support rod (17) and the kit (4); Two alignment groups are arranged between the kit (4) and the conveying frame (5) for aligning the pipe opening of the pipeline (1) with the kit (4), and the two alignment groups are arranged in front of the two conveying frames (5) respectively; The alignment group comprises an inclined rod (9) and a sliding member (13); the inclined rod (9) is slidably connected to a connecting member (10) along the axial direction; a sixth spring (35) is fixedly connected between the connecting member (10) and the inclined rod (9); a contact piece (11) is rotatably connected to the connecting member (10); a first torsion spring (12) is sleeved on the rotating shaft of the contact piece (11); the contact piece (11) can only rotate forward; the sliding member (13) is slidably connected to the inner wall of the sleeve (4); a first spring (14) is fixedly connected between the sliding member (13) and the sleeve (4); and a rubber layer is glued to the inner wall of the sliding member (13); The support rod (17) is provided with a locking group, and the locking group is used to lock the sliding member (13) after the sliding member (13) moves relative to the sleeve (4) following the pipeline (1); The locking group comprises a fixed rod (19) and a first rack rod (22), the fixed rod (19) being slidably connected to a side wall of a support rod (17), a third spring (20) being fixedly connected between the fixed rod (19) and the support rod (17), an end of the fixed rod (19) being rotatably connected to an electric control gear (21), the electric control gear (21) being controlled by an electric control component to be locked and freely rotatable, and the first rack rod (22) being fixed to an inner wall of a sliding member (13); The distance between the two conveying grooves (7) is greater than the length of the rear end of the molded part (6); the conveying frame (5) is rotatably connected to a gear (23); a second torsion spring (24) is sleeved on the rotating shaft of the gear (23); a centering rod (25) is fixedly connected to the two gears (23); a centering piece (26) is fixedly connected to the two centering rods (25); the two gears (23) are meshed with a second rack rod (27); and the two second rack rods (27) are fixedly connected to an adjusting rod. (28), the rear ends of the two adjusting rods (28) are provided with inclined surfaces, the two adjusting rods (28) are slidably connected with slots (29), the two slots (29) are respectively provided on the two conveying racks (5), a fourth spring (30) is fixedly connected between the two adjusting rods (28) and the conveying racks (5), and an extrusion rod (31) is provided at the rear of the two adjusting rods (28), and the extrusion rod (31) is used to make the adjusting rod (28) slide along the slot (29) when the forming group is working; The two centering pieces (26) can make the axis of the sleeve (4) coincide with the axis of the molded piece (6) when the two sleeves (4) are clamped; The forming group comprises a third cylinder (32), the third cylinder (32) is fixedly connected to the workbench (2), a push block (33) is fixedly connected to the telescopic end of the third cylinder (32), the push block (33) is arranged directly below the push plate (8), and the extrusion rod (31) is fixedly connected to the left and right sides of the push block (33); The push block (33) is slidably connected to the push plate (8), and a fifth spring (34) is fixedly connected between the push block (33) and the push plate (8).

2. The expansion device for post-processing of a plastic pipe according to claim 1, characterized in that: A through hole is provided on the rear end of the molded part (6).

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