Extrusion device for plastic pipe

Abstract

One end of a machine barrel is provided with a feeding port, the machine barrel is installed on a machine frame, the other end of the machine barrel is provided with a discharging port, the discharging port is connected with an extrusion die, a part of a screw rod is arranged in the machine barrel, a plurality of heaters are sleeved on the machine barrel in a segmented mode and fixed with the machine barrel, and the machine barrel is connected with the machine frame. The transmission mechanism is installed on the machine frame and connected with the motor, one end of the connecting mechanism is connected with the machine barrel, the other end of the connecting mechanism is connected with the output end of the transmission mechanism, an axial assembly hole is formed in one end of the screw rod, and the screw rod is connected with the motor. One end of the cooling assembly penetrates through the transmission mechanism and the connecting mechanism and then extends into the assembly hole, the cooling assembly is matched with the hole wall of the assembly hole, and the other end of the cooling assembly is located outside the transmission mechanism. According to the utility model, the power transmission is not influenced while the cooling effect is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of plastic pipes, and particularly relates to an extrusion device for plastic pipes. Background Technique

[0002] Due to the advantages in terms of energy conservation, land conservation, water conservation, and material conservation, plastic pipes are widely used in fields such as construction and industrial applications. According to statistics, the total output of plastic pipes in China reached 18 million tons in 2021. With the diversification of plastic pipe styles and processing methods, the forming process of plastic pipes also shows a trend of diversification. Common plastic pipe forming methods include injection molding, blow molding, extrusion molding, etc. In different forming processes, the use of molds plays a key role in the quality of forming and producing products. As a continuous forming method, extrusion molding has been widely used in the manufacturing and production of plastic pipes.

[0003] The extrusion method is the main method for current production of plastic pipes. For example, CN214188374 U discloses a plastic pipe screw extruder, which includes a frame on which a barrel and a motor are fixed. One end of the barrel is provided with a feed inlet, and the other end is provided with a discharge outlet. The feed inlet is connected to the discharge port of a feeding box, and the discharge outlet is connected to a head. A screw rotates in the barrel, and the screw is driven to rotate by the motor. The barrel is sequentially divided into a first heating zone, a second heating zone, a third heating zone, a fourth heating zone, and a fifth heating zone from the feed end to the discharge end, and 3 - 5 heating coils are respectively arranged in the five heating zones. The barrel is provided with a sandwich at one end of the feed inlet, and a water inlet and a water outlet are respectively opened in the sandwich. The water inlet is connected to a total water inlet pipe through a pipeline, and the water outlet is connected to a total water outlet pipe through a pipeline.

[0004] For the above-mentioned extruder, due to too high preheating temperature, a molten film appears. Therefore, a cooling structure is formed between the barrel and the sandwich, which plays a role of preheating or cooling according to the use requirements, so that the temperature of the conveyed material is kept below the softening point or melting point to avoid the appearance of the molten film, so as to maintain the solid friction property of the material and increase the solid conveying capacity. However, although this structure can reduce the temperature of the screw, since the cooling structure is located between the barrel and the sandwich, the cooling structure blocks the heat emitted by the heating coil, which will cause the heating coil to require a higher power to heat the granular plastic to the molten state. Summary of the Utility Model

[0005] The utility model provides an extrusion device for plastic pipes, which can play a role in cooling while not affecting the transmission of power.

[0006] The technical solutions to solve the above problems are as follows:

[0007] Extrusion device for plastic pipes, including a plastic extruder and an extrusion die. The plastic extruder includes a frame, a barrel, a motor, a screw, and multiple heaters. One end of the barrel is provided with a feed inlet, the barrel is installed on the frame, the other end of the barrel is provided with a discharge outlet, and the discharge outlet is connected to the extrusion die. A part of the screw is arranged inside the barrel, and the multiple heaters are sleeved on the barrel in sections and fixed to the barrel. It also includes a transmission mechanism, a connecting mechanism, and a cooling component. The transmission mechanism is installed on the frame, the transmission mechanism is connected to the motor, one end of the connecting mechanism is connected to the barrel, and the other end of the connecting mechanism is connected to the output end of the transmission mechanism. An axial assembly hole is provided at one end of the screw, and one end of the cooling component passes through the transmission mechanism and the connecting mechanism and then extends into the assembly hole. The cooling component cooperates with the hole wall of the assembly hole, and the other end of the cooling component is located outside the transmission mechanism.

[0008] Furthermore, the transmission mechanism includes a support seat, a hollow transmission shaft, and an intermediate transmission mechanism. The support seat is installed on the frame, the hollow transmission shaft passes through the support seat and is rotationally matched with the support seat. One end of the hollow transmission shaft is connected to the connecting mechanism, and the other end of the hollow transmission shaft is connected to the intermediate transmission mechanism. The cooling component passes through the hollow transmission shaft.

[0009] Furthermore, the connecting mechanism includes a support housing, a first bearing, a transmission sleeve, and a second bearing. One end of the support housing is fixed to the barrel, the first bearing is located inside the support housing and fixed to the support housing, the transmission sleeve is matched with the first bearing, one end of the screw is fixed to one end of the transmission sleeve, the other end of the transmission sleeve is fixed to the output end of the transmission mechanism, the second bearing is located inside the transmission sleeve and matched with the transmission sleeve, one end of the screw forms an axial limit for one end of the second bearing, and the transmission sleeve forms an axial limit for the other end of the second bearing.

[0010] Furthermore, the cooling component includes an outer tube, an inner tube, a water inlet pipe, and a water return pipe. One end of the outer tube is closed and the other end has an opening. One end of the inner tube is inserted into the outer tube through the opening end of the outer tube, and an annular cavity is formed between the inner tube and the outer tube. There is a distance between one end of the inner tube and the closed end of the outer tube. One end of the inner tube has an opening, and the other end of the inner tube is exposed outside the outer tube. The outer tube is connected to the water inlet pipe, and the inner tube is connected to the water return pipe.

[0011] Furthermore, a polytetrafluoroethylene layer is provided on the outer surface of the outer tube.

[0012] Furthermore, the cooling component further includes a support frame. Radial protrusions are provided on the inner wall surface of the outer tube, the inner tube passes through the radial protrusions, the radial protrusions support the inner tube, and an annular cavity is formed between the inner tube and the outer tube. The support frame is fixed to the frame (1), and the inner tube is connected to the support frame.

[0013] When the utility model is in use, the cooling liquid enters the outer tube through the water inlet pipe. The cooling liquid flows along the annular cavity between the inner tube and the outer tube. After the cooling liquid reaches the closed end of the outer tube, it cannot flow out through the closed end of the outer tube. Therefore, the cooling liquid can only flow into the inner tube and flow along the inner tube into the water return pipe. During this process, a small part of the heat on the screw is taken away by the cooling liquid through heat transfer or thermal radiation, so as to cool the screw. After the cooling structure of the utility model is improved, not only can the formation of a molten film on the screw be avoided, but also because the cooling structure is located inside the screw, the barrier of the heater to the screw is avoided, and further the loss of heating energy is avoided.

[0014] In addition, a connecting mechanism is used to connect the barrel and the transmission mechanism, and the connecting mechanism is also matched with the cooling component. Therefore, this structure not only sets a cooling structure at the center of the screw, but also transmits power to the screw. Therefore, while cooling is achieved, the transmission of power is not affected. Description of the Drawings

[0015] Figure 1 It is a sectional view of the plastic pipe extrusion device of the utility model.

[0016] Figure 2 It is a three-dimensional view of the plastic extruder.

[0017] Figure 3 is Figure 1 The enlarged view of part Q in

[0018] Marks in the drawings:

[0019] Plastic extruder A, extrusion die B, transmission mechanism C, connecting mechanism D, cooling component E.

[0020] Frame 1, barrel 2, motor 3, screw 4, assembly hole 4a, limit step 4b, heater 5, support seat 6, hollow transmission shaft 7, convex part 7a, intermediate transmission mechanism 8, support shell 8a, first bearing 9, transmission sleeve 10, second bearing 11, outer tube 12, radial protrusion 12a, inner tube 13, water inlet pipe 14, water return pipe 15, support frame 16, limit sleeve 17, gasket 18, third bearing 19. Detailed Description of the Invention

[0021] The following further describes the present utility model in detail with reference to the drawings and specific embodiments.

[0022] As Figures 1 to 3 , the plastic pipe extrusion device of the present utility model includes a plastic extruder A, an extrusion die B, a transmission mechanism C, a connecting mechanism D, and a cooling component E. The following describes each part and the relationship between them:

[0023] The plastic extruder A includes a frame 1, a barrel 2, a motor 3, a screw 4, and a plurality of heaters 5. One end of the barrel 2 is provided with a feed port, and a feed hopper is arranged at the feed port. Plastic particles sequentially enter the barrel 2 through the feed hopper and the feed port.

[0024] The barrel 2 is installed on the frame 1. The other end of the barrel 2 is provided with a discharge port, and the discharge port is connected to an extrusion die B. A part of the screw 4 is arranged in the barrel 2. The plurality of heaters 5 are sleeved on the barrel 2 in sections and fixed to the barrel 2. The heaters 5 are induction heaters. Plastic particles are input into the plastic extruder A. The plastic particles move under the push of the screw 4 in the plastic extruder A. When the plastic particles move to the area where the heaters 5 are located, they are gradually heated and form a molten state. The molten plastic enters the extrusion die B and is formed into a pipe through the action of the extrusion die B.

[0025] A transmission mechanism C is installed on the frame 1. The transmission mechanism C is connected to the motor 3. The transmission mechanism C includes a support seat 6, a hollow transmission shaft 7, and an intermediate transmission mechanism 8. The support seat 6 is installed on the frame 1. The hollow transmission shaft 7 passes through the support seat 6 and is rotationally matched with the support seat 6. One end of the hollow transmission shaft 7 is connected to a connection mechanism D, and the other end of the hollow transmission shaft 7 is connected to the intermediate transmission mechanism 8. The intermediate transmission mechanism 8 can adopt a belt transmission mechanism or a gear transmission mechanism. One end of the hollow transmission shaft 7 is provided with a convex portion 7a. The convex portion 7a is exposed outside the support seat 6. One end of the convex portion 7a abuts against the axial end face of the support seat 6, so that the convex portion 7a obtains axial limit. A spline is provided on the convex portion 7a.

[0026] One end of the connection mechanism D is connected to the barrel 2, and the other end of the connection mechanism D is connected to the output end of the transmission mechanism C. The connection mechanism D includes a support housing 8a, a first bearing 9, a transmission sleeve 10, and a second bearing 11. One end of the support housing 8a is fixed to the barrel 2. The first bearing 9 is located in the support housing 8a and fixed to the support housing 8a. The transmission sleeve 10 is matched with the first bearing 9. One end of the screw 4 is fixed to one end of the transmission sleeve 10. The other end of the transmission sleeve 10 is fixed to the output end of the transmission mechanism C. The second bearing 11 is located inside the transmission sleeve 10 and matched with the transmission sleeve 10. One end of the screw 4 forms an axial limit for the second bearing 11, and the transmission sleeve 10 forms an axial limit for the other end of the second bearing 11. When the screw 4 rotates, it can drive the transmission sleeve 10 to rotate relative to the support housing 8a.

[0027] One end of the transmission sleeve 10 is circumferentially fixed to the screw 4 through a spline. The other end of the transmission sleeve 10 is circumferentially fixed to the hollow transmission shaft 7 through a spline, that is, the other end of the transmission sleeve 10 is circumferentially fixed to the convex portion 7a through a spline. Shoulders are provided on both the transmission sleeve 10 and the hollow transmission shaft 7. The shoulders on the transmission sleeve 10 and the hollow transmission shaft 7 are engaged and matched, and one end of the transmission sleeve 10 obtains axial limit.

[0028] The connecting mechanism D further includes a limit sleeve 17, a gasket 18, and a third bearing 19. A limit step 4b is provided on the screw rod 4. The limit sleeve 17 is sleeved on the screw rod 4. The limit sleeve 17 cooperates with the limit step 4b, and the limit sleeve 17 is limited by the limit step 4b. The gasket 18 is sleeved on the screw rod 4, and the gasket 18 is located between the limit sleeve 17 and the transmission sleeve 10, and the other end of the transmission sleeve 10 obtains axial limitation. The inner ring of the third bearing 19 is sleeved on the limit sleeve 17, and the outer ring of the third bearing 19 cooperates with the support housing 8a. Through the action of the third bearing 19, when the screw rod 4 rotates, the limit sleeve 17 can rotate relative to the support housing 8a.

[0029] One end of the screw rod 4 is provided with an axial assembly hole 4a. One end of the cooling assembly E passes through the transmission mechanism C and the connecting mechanism D and then extends into the assembly hole 4a, that is, the cooling assembly E passes through the hollow transmission shaft 7. The cooling assembly E cooperates with the hole wall of the assembly hole 4a, and the other end of the cooling assembly E is located outside the transmission mechanism C.

[0030] The cooling assembly E includes an outer tube 12, an inner tube 13, a water inlet pipe 14, and a water return pipe 15. The outer tube 12 is inserted into the assembly hole 4a and cooperates with the assembly hole 4a. The outer surface of the outer tube 12 is provided with a polytetrafluoroethylene layer.

[0031] One end of the outer tube 12 is closed and the other end has an opening. One end of the inner tube 13 is inserted into the outer tube 12 through the open end of the outer tube, and an annular cavity is formed between the inner tube 13 and the outer tube 12. There is a distance between one end of the inner tube 13 and the closed end of the outer tube 12. One end of the inner tube 13 has an opening, and the other end of the inner tube 13 is exposed outside the outer tube 12. The outer tube 12 is connected to the water inlet pipe 14, and the inner tube 13 is connected to the water return pipe 15.

[0032] The cooling liquid enters the outer tube 12 through the water inlet pipe 14. The coolant flows along the annular cavity between the inner tube 13 and the outer tube 12. When the coolant reaches the closed end of the outer tube 12, the coolant cannot flow out through the closed end of the outer tube 12. Therefore, the coolant can only flow into the inner tube 13 and flow along the inner tube 13 into the water return pipe 15. During this process, a small part of the heat on the screw rod 4 is taken away by the coolant through heat transfer or heat radiation, thereby cooling the screw rod 4. The improvement of the cooling structure of the present utility model can not only avoid the formation of a molten film on the screw rod 4, but also, since the cooling structure is located inside the screw rod 4, it avoids the blockage of the heater to the screw rod 4, thereby avoiding the loss of heating energy.

[0033] The cooling component E further includes a support frame 16. A radial protrusion 12a is provided on the inner wall surface of the outer tube 12. The inner tube 13 passes through the radial protrusion 12a. The radial protrusion 12a forms a support for the inner tube 13 and forms an annular cavity between the inner tube 13 and the outer tube 12. The radial protrusion 12a and the inner tube 13 are also fixed by welding. After welding, the gap between the radial protrusion 12a and the inner tube 13 can be filled to prevent the coolant from flowing out through the gap between the radial protrusion 12a and the inner tube 13. The support frame 16 is fixed to the frame 1, and the inner tube 13 is connected to the support frame 16. In this embodiment, the second bearing 11 is sleeved on the outer tube 12. The second bearing 11, the radial protrusion 12a and the support frame 16 form a supporting effect on the outer tube 12 and the inner tube 13, preventing the axial directions of the outer tube 12 and the inner tube 13 from changing, and further preventing the outer tube 12 from interfering with other parts.

[0034] Finally, it should be noted that the above embodiments are only the preferred embodiments of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit it, let alone to limit the protection scope of the present invention; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the protection scope of the claims.

Claims

1. A plastic pipe extrusion device, comprising a plastic extruder (A) and an extrusion die (B), wherein the plastic extruder (A) comprises a frame (1), a barrel (2), a motor (3), a screw (4), and a plurality of heaters (5), wherein a feed port is provided at one end of the barrel (2), the barrel (2) is mounted on the frame (1), a discharge port is provided at the other end of the barrel (2), the discharge port is connected to the extrusion die (B), a portion of the screw (4) is arranged in the barrel (2), and a plurality of heaters (5) are segmentally sleeved on the barrel (2) and fixed to the barrel (2), characterized in that: It also includes a transmission mechanism (C), a connecting mechanism (D), and a cooling assembly (E). The transmission mechanism (C) is installed on the frame (1), the transmission mechanism (C) is connected to the motor (3), one end of the connecting mechanism (D) is connected to the barrel (2), and the other end of the connecting mechanism (D) is connected to the output end of the transmission mechanism (C). One end of the screw (4) is provided with an axial assembly hole (4a), one end of the cooling assembly (E) passes through the transmission mechanism (C) and the connecting mechanism (D) and then extends into the assembly hole (4a), the cooling assembly (E) cooperates with the hole wall of the assembly hole (4a), and the other end of the cooling assembly (E) is located outside the transmission mechanism (C).

2. The plastic pipe extrusion device according to claim 1, characterized in that: The transmission mechanism (C) comprises a support base (6), a hollow transmission shaft (7), and an intermediate transmission mechanism (8); the support base (6) is mounted on the frame (1); the hollow transmission shaft (7) passes through the support base (6) and is rotatably matched with the support base (6); one end of the hollow transmission shaft (7) is connected to the connecting mechanism (D); the other end of the hollow transmission shaft (7) is connected to the intermediate transmission mechanism (8); and the cooling component (E) passes through the hollow transmission shaft (7).

3. The plastic pipe extrusion device according to claim 1, characterized in that: The connecting mechanism (D) comprises a supporting shell (8a), a first bearing (9), a transmission sleeve (10), and a second bearing (11); one end of the supporting shell (8a) is fixed to the barrel (2); the first bearing (9) is located in the supporting shell (8a) and is fixed to the supporting shell (8a); the transmission sleeve (10) cooperates with the first bearing (9); one end of the screw rod (4) is fixed to one end of the transmission sleeve (10); the other end of the transmission sleeve (10) is fixed to the output end of the transmission mechanism (C); the second bearing (11) is located in the transmission sleeve (10) and cooperates with the transmission sleeve (10); the screw rod (4) forms an axial limit on one end of the second bearing (11); and the transmission sleeve (10) forms an axial limit on the other end of the second bearing (11).

4. The plastic pipe extrusion device according to claim 1, characterized in that: The cooling component (E) comprises an outer tube (12), an inner tube (13), a water inlet pipe (14), and a water return pipe (15); one end of the outer tube (12) is closed and the other end has an opening; one end of the inner tube (13) is inserted into the outer tube (12) through the open end of the outer tube; an annular cavity is formed between the inner tube (13) and the outer tube (12); there is a gap between one end of the inner tube (13) and the closed end of the outer tube (12); one end of the inner tube (13) has an opening; the other end of the inner tube (13) is exposed to the outside of the outer tube (12); the outer tube (12) is connected to the water inlet pipe (14), and the inner tube (13) is connected to the water return pipe (15).

5. The plastic pipe extrusion device according to claim 4, characterized in that: The outer surface of the outer tube (12) is provided with a polytetrafluoroethylene layer.

6. The plastic pipe extrusion device according to claim 4, characterized in that: The cooling assembly (E) also includes a support frame (16), the inner wall surface of the outer tube (12) is provided with a radial protrusion (12a), the inner tube (13) passes through the radial protrusion (12a), the radial protrusion (12a) supports the inner tube (13), and forms an annular cavity between the inner tube (13) and the outer tube (12), the support frame (16) is fixed to the frame (1), and the inner tube (13) is connected to the support frame (16).

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