Injection molding device applied to plastic pipe production

Abstract

The application discloses an injection molding device applied to plastic pipe production and relates to the technical field of plastic pipe injection molding. The injection molding device comprises an injection molding machine body, a screw extrusion group arranged above the left end of the injection molding machine body, a forming mechanism arranged above the right end of the injection molding machine body, and an injection molding fixed mold contained in the forming mechanism. An equal number of forming cavities are arranged inside the injection molding sliding mold. A material ejection mechanism is arranged at the right end of the injection molding sliding mold, the material ejection mechanism comprises a material ejection sliding sleeve, and a transmission vertical plate is fixedly installed at the right end of the material ejection sliding sleeve. The injection molding device applied to plastic pipe production combines the injection molding fixed mold and the injection molding sliding mold, realizes the forming operation of waste plastic materials in the forming cavities, and realizes the batch forming operation after the cooling of the main circulating coil and the auxiliary circulating coil.

Description

Technical Field

[0001] This invention relates to the field of plastic pipe injection molding technology, specifically to an injection molding device used in the production of plastic pipes. Background Technology

[0002] Plastic pipe injection molding is a mature plastic molding process developed based on the principle of metal die casting. Granular or powdered plastic raw materials such as PE, PVC, and PP suitable for pipe applications are added to the hopper of the injection molding machine. The raw materials are uniformly melted and plasticized into a fluid state by external heating of the barrel and shearing action of the screw. The molten material is then pushed by the high pressure of the screw into a pre-closed special mold with a precise pipe cavity at a set speed and pressure. The molten material is quickly cooled and solidified by the circulating cooling water circuit built into the mold. After the material has fully solidified, the mold is opened and the pipe is ejected, thus obtaining a finished plastic pipe or pipe fitting with a regular shape, dimensional accuracy, and matching connection structure in one go.

[0003] Application CN117841313A discloses a rapid cooling injection molding machine for preparing plastic pipes. Through the configuration of the injection conveying assembly, molten plastic is injected into the injection mold. A pre-cooling assembly pre-cools the injected molten plastic to reduce its temperature during conveying. Simultaneously, a mold cooling assembly continuously cools the injection mold. Coolant circulates from the plastic pipe discharge point to the molten plastic input point to rapidly cool the injection mold and the molten plastic inside, achieving rapid cooling and molding of the plastic pipe, thereby improving the utilization efficiency of the injection molding machine.

[0004] Application CN117754812A discloses an injection molding equipment for producing plastic pipes. By setting up an injection barrel, molten material can be placed and, under the action of the extrusion mechanism, the material can be leaked into the molding device. The injection barrel has a barrel body for storing injection material and a threaded ring fixedly installed at the bottom of the injection barrel. The outer surface of the injection barrel is fixedly connected to a feed port and a support ring fixedly installed at the bottom of the extrusion mechanism, so as to achieve the effect of molding plastic pipes with a smooth outer surface.

[0005] However, the injection molding equipment disclosed above for the production of plastic pipes still has the following problems in actual use: the processing operation is achieved by conveying the molten material into the molding mold, but the injection mold of such plastic pipes usually has multiple cavities to process and mold multiple plastic pipes at one time, but it lacks batch demolding and unloading components, which makes it impossible to efficiently unload the material after the plastic pipe molding operation. At the same time, there are temperature differences between multiple cavities during cooling, resulting in uneven cooling of some plastic pipes.

[0006] Therefore, we propose an injection molding device for the production of plastic pipes to solve the problems mentioned above. Summary of the Invention

[0007] The purpose of this invention is to provide an injection molding device for the production of plastic pipes. This device addresses the problem that existing plastic pipe injection molds typically have multiple cavities to process multiple plastic pipes at once, but lack batch demolding and unloading components. This results in inefficient unloading after the plastic pipes are formed, and the temperature difference between the multiple cavities during cooling leads to uneven cooling of some plastic pipes.

[0008] To achieve the above objectives, the present invention provides the following technical solution: an injection molding device for the production of plastic pipes, comprising an injection molding machine body, wherein a screw extrusion assembly is provided above the left end of the injection molding machine body, and the screw extrusion assembly extrudes and conveys molten waste plastic material; A molding mechanism is provided on the upper right end of the injection molding machine body, and the molding mechanism includes an injection mold, and an injection sliding mold is provided on the right end of the injection mold. The injection molding mold has equidistant molding cavities inside, and an injection flow channel is provided at the left end of the adjacent molding cavity. The injection molding slip mold is provided with an ejector mechanism at its right end, and the ejector mechanism includes an ejector sleeve, and a transmission vertical plate is fixedly installed at the right end of the ejector sleeve.

[0009] Preferably, the molding mechanism includes an injection groove, which is located at the center of the injection mold. The left end of the injection mold is connected to the screw extrusion assembly to extrude the molten waste plastic into the injection groove inside the injection mold. The injection groove is also connected to the molding cavity.

[0010] Preferably, the molding mechanism includes a filling rod, and the left end of the filling rod is inserted into the molding cavity opened inside the injection mold. The filling rod and the molding cavity are distributed in a one-to-one correspondence. The filling rod is located at the center of the molding cavity, and the molding cavity and the injection flow channel are interconnected.

[0011] Preferably, the molding mechanism includes a positioning frame, which is fixedly installed on the right outer wall of the injection molding mold, and an extension rod is fixedly installed at equal intervals on the left outer wall of the positioning frame. The left end of the extension rod is fixedly connected to the right end of the filling rod, and the filling rod and the extension rod slide synchronously with the injection molding mold.

[0012] Preferably, the molding mechanism includes a positioning tail plate, which is fixedly installed on the right end of the top surface of the injection molding machine body. The four corners of the positioning tail plate are fixedly connected to the right end of the guide slide rod, and the left end of the guide slide rod extends to the left side of the top surface of the injection molding machine body. The left end of the guide slide rod is fixedly located inside the injection mold.

[0013] Preferably, the molding mechanism includes a protective cover, which is fixedly installed on the right side of the top surface of the injection molding machine body. A hydraulic cylinder is fixedly installed at the center of the top surface of the protective cover, and the left end extension part of the hydraulic cylinder is fixedly connected to the top surface of the injection molding mold by bolts. At the same time, the injection molding mold is slidably sleeved on the outer wall of the guide slide rod.

[0014] Preferably, the ejector mechanism includes an ejector sleeve that is slidably sleeved on the outer wall of the filling rod, and the left end of the ejector sleeve is inserted into the molding cavity opened inside the injection mold. The molding cavity and the ejector sleeve together form a plastic tube molding cavity. The transmission vertical plate at the right end of the ejector sleeve is slidably disposed between the injection mold and the positioning frame.

[0015] Preferably, the ejector mechanism includes a main ejector side frame, which is fixedly installed on the front and rear sides of the right end of the transmission vertical plate. A secondary ejector side frame is provided at the right end of the main ejector side frame and is fixedly installed on the right side of the top surface of the injection molding machine body. In the initial state, the secondary ejector side frame does not contact the main ejector side frame.

[0016] Preferably, the top material mechanism includes a main circulation coil and a secondary circulation coil, both of which are located on the left outer wall of the transmission vertical plate. Both the main circulation coil and the secondary circulation coil are arranged in an "S" shape around the outer wall of the top material sliding sleeve, and the main circulation coil and the secondary circulation coil are used to cool and shape the top material sliding sleeve and the molten waste plastic at the end.

[0017] Preferably, the top material mechanism includes an input pipe and an output pipe, with the left end of the input pipe fixedly connected to one end of the main circulation coil and the auxiliary circulation coil, and the left end of the output pipe fixedly connected to the other end of the main circulation coil and the auxiliary circulation coil. The right ends of the input pipe and the output pipe are connected to a liquid-cooled pump box, which is fixedly installed on the inner wall of the positioning tail plate.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: This injection molding device applied to the production of plastic pipes combines a fixed injection mold and a sliding injection mold, allowing waste plastic to be molded in the molding cavity. After cooling by the main circulation coil and the auxiliary circulation coil, the plastic pipe is ejected through the ejector sleeve by the movement of the sliding injection mold, thereby realizing batch molding processing. The specific details are as follows: 1. The injection molding slide is driven by a hydraulic cylinder to move along the direction of the guide slide rod, so that it merges with the injection mold on the right side of the top surface of the injection molding machine body. The left end of the extension rod is fixedly connected to the right end of the filling rod. The positioning frame is fixedly installed on the outer wall of the right end of the injection molding slide. The extension rod is fixedly installed at equal intervals on the outer wall of the left side of the positioning frame. A stable hollow structure of plastic tube is formed inside the molding cavity. The filling rod is rigidly locked with the positioning frame through the extension rod, forming the cavity required for plastic tube molding.

[0019] 2. The left end of the input pipe is fixedly connected to one end of the main circulation coil and the auxiliary circulation coil, respectively. The left end of the output pipe is fixedly connected to the other end of the main circulation coil and the auxiliary circulation coil, respectively. The right ends of the input pipe and the output pipe are connected to a liquid cooling pump box, forming an independent closed circulation loop. The coolant fully contacts the outer wall of the top material sliding sleeve in the "S" shaped path, quickly removing the curing heat of the plastic tube inside the molding cavity. There is no local temperature difference during the cooling process, and the plastic tube is stress-free after shaping.

[0020] 3. During the injection molding process, the main ejector side frame and the secondary ejector side frame automatically contact and abut against each other. The transmission vertical plate drives the ejector sleeve to remain relatively stationary. The left end of the ejector sleeve directly abuts against the molded plastic tube to complete demolding. The ejector assembly does not require an additional power source. The mold opening and demolding actions are completely synchronized. The modular design allows the main ejector side frame and the secondary ejector side frame to be adjusted in position independently. Plastic tubes of different lengths do not get stuck or scratched during demolding. After demolding, the plastic tube is collected directly through the discharge port at the bottom of the injection molding machine body. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the present invention; Figure 2 This is a schematic diagram of the injection molding fixed mold installation structure of the present invention; Figure 3 This is a schematic diagram of the installation structure of the injection molding fixed mold and the injection molding sliding mold of the present invention; Figure 4 This is a schematic diagram of the initial position of the injection molding sliding mold according to the present invention; Figure 5 For the present invention Figure 4 Enlarged structural diagram at point A in the middle; Figure 6 This is a schematic diagram of the installation structure of the filling fixed rod and the extension fixed rod of the present invention; Figure 7 This is a three-dimensional structural diagram of the top material sliding sleeve and transmission vertical plate of the present invention; Figure 8 This is a schematic diagram of the three-dimensional structure of the auxiliary top material side frame of the present invention; Figure 9 For the present invention Figure 8 Enlarged structural diagram at point B; Figure 10 This is a schematic diagram of the installation structure of the main circulation coil and the auxiliary circulation coil of the present invention; Figure 11 This is a three-dimensional structural diagram of the main circulation coil and the auxiliary circulation coil of the present invention.

[0022] In the diagram: 1. Injection molding machine body; 2. Screw extrusion assembly; 3. Injection mold; 4. Injection sliding mold; 5. Molding cavity; 6. Injection runner; 7. Ejector sleeve; 8. Transmission vertical plate; 9. Injection slot; 10. Filling rod; 11. Positioning frame; 12. Extension rod; 13. Positioning tail plate; 14. Guide slide bar; 15. Protective cover; 16. Hydraulic cylinder; 17. Main ejector side frame; 18. Secondary ejector side frame; 19. Main circulation coil; 20. Secondary circulation coil; 21. Input pipe; 22. Output pipe; 23. Liquid cooling pump box. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Please see Figures 1-11 The present invention provides the following technical solution: Example 1: To address the problems existing in the injection molding process of plastic pipe production, this example discloses the following technical solution: an injection molding device for plastic pipe production, including an injection molding machine body 1. A screw extrusion assembly 2 is provided above the left end of the injection molding machine body 1, which extrudes and conveys molten waste plastic. A molding mechanism is provided above the right end of the injection molding machine body 1, and the molding mechanism includes an injection mold 3, and an injection sliding mold 4 is provided at the right end of the injection mold 3. The injection sliding mold 4 has molding cavities 5 evenly spaced inside, and an injection flow channel 6 is provided at the left end of adjacent molding cavities 5. The molding mechanism includes a positioning tail plate 13, which is fixedly installed on the right end of the top surface of the injection molding machine body 1. The four corners of the positioning tail plate 13 are fixedly connected to the right end of a guide slide rod 14, and the left end of the guide slide rod 14 extends to the left side of the top surface of the injection molding machine body 1. The left end of the guide slide rod 14 is fixedly located inside the injection mold 3.

[0025] The molding mechanism includes a protective cover 15, which is fixedly installed on the right side of the top surface of the injection molding machine body 1. A hydraulic cylinder 16 is fixedly installed at the center of the top surface of the protective cover 15. The telescopic part of the left end of the hydraulic cylinder 16 is fixedly connected to the top surface of the injection molding slide mold 4 by bolts. At the same time, the injection molding slide mold 4 is slidably sleeved on the outer wall of the guide slide rod 14.

[0026] like Figures 1-3 As shown, when injection molding of plastic pipe is required, the hydraulic cylinder 16 at the top of the protective cover 15 on the right side of the injection molding machine body 1 first operates. The telescopic part at the left end of the hydraulic cylinder 16 drives the fixedly connected injection mold 4 to move. The injection mold 4 moves along the guide slide rod 14 that runs through the four corners inside, so that the injection mold 4 slides to the right outer wall of the left injection mold 3, forming a closed and complete plastic pipe molding cavity between it and the injection mold 3.

[0027] Furthermore, the screw extrusion assembly 2 on the top left of the injection molding machine body 1 extrudes and conveys the molten waste plastic material. The molten material is conveyed to the interior of the through-connected molding cavity 5 through the injection groove hole 9 opened at the center of the injection mold 3. At the same time, after the molten material enters the injection sliding mold 4, it flows through the injection flow channels 6 opened at equal intervals, and then fills the interior of the molding cavity 5 opened at equal intervals to complete the molding operation.

[0028] Example 2: In order to solve the problems existing in the injection molding process of existing plastic pipes, this example discloses the following technical solution: the molding mechanism includes an injection groove 9, and the injection groove 9 is opened at the center of the injection mold 3. The left end of the injection mold 3 is connected to the screw extrusion assembly 2 to extrude the molten waste plastic into the injection groove 9 opened inside the injection mold 3. Moreover, the injection groove 9 is interconnected with the molding cavity 5.

[0029] The molding mechanism includes a filling rod 10, the left end of which is inserted into the molding cavity 5 inside the injection mold 4. The filling rods 10 and the molding cavities 5 are distributed in a one-to-one correspondence, and the filling rods 10 are located at the center of the molding cavity 5. The molding cavity 5 and the injection runner 6 are interconnected. The molding mechanism includes a positioning frame 11, which is fixedly installed on the right outer wall of the injection mold 4. Extension rods 12 are fixedly installed at equal intervals on the left outer wall of the positioning frame 11. The left end of the extension rods 12 is fixedly connected to the right end of the filling rod 10. The filling rods 10 and the extension rods 12 slide synchronously with the injection mold 4.

[0030] like Figures 4-6As shown, the molten material is conveyed into the molding cavity 5 inside the injection molding mold 4. The filling rod 10 at the center of the molding cavity 5 is fixedly installed with the positioning frame 11 by extending the rod 12, so that the filling rod 10 is located at the center of the molten material inside the molding cavity 5, and forms the hollow structure of the plastic tube through the filling rod 10. At the same time, the right end of the inside of the molding cavity 5 is filled by the ejector sleeve 7, so that the molten material flows to one end of the ejector sleeve 7 for limitation, and forms the end of the plastic tube by the ejector sleeve 7, which assists in the injection molding of the plastic tube.

[0031] Example 3: In order to solve the problems existing in the injection molding process of existing plastic pipes, this example discloses the following technical solution: the ejector mechanism includes a main circulation coil 19 and a secondary circulation coil 20, and both the main circulation coil 19 and the secondary circulation coil 20 are set on the left outer wall of the transmission vertical plate 8. Both the main circulation coil 19 and the secondary circulation coil 20 are arranged in an "S" shape around the outer wall of the ejector sleeve 7. The main circulation coil 19 and the secondary circulation coil 20 cool and mold the ejector sleeve 7 and the molten waste plastic at the end.

[0032] The top material mechanism includes an input pipe 21 and an output pipe 22. The left end of the input pipe 21 is fixedly connected to one end of the main circulation coil 19 and the auxiliary circulation coil 20, respectively. The left end of the output pipe 22 is fixedly connected to the other end of the main circulation coil 19 and the auxiliary circulation coil 20, respectively. The right ends of the input pipe 21 and the output pipe 22 are connected to a liquid-cooled pump box 23, which is fixedly installed on the inner wall of the positioning tail plate 13.

[0033] like Figures 10-11 As shown, molten plastic is filled and formed inside the injection mold 3 and the injection sliding mold 4. The liquid cooling pump box 23 inside the positioning tail plate 13 provides auxiliary cooling for the forming process. The liquid cooling pump box 23 delivers coolant to the left end through the through-connected input pipe 21, allowing the coolant to enter the main circulation coil 19 and the auxiliary circulation coil 20. The coolant flows through the "S"-shaped main circulation coil 19 and the auxiliary circulation coil 20, thereby cooling the ejector sleeve 7 on the outer right side of the injection sliding mold 4. The ejector sleeve 7 exchanges heat at its end, thus assisting in the shaping of the plastic tube inside the forming cavity 5. The circulated coolant is then returned to the liquid cooling pump box 23 through the output pipe 22 for recycling, thereby achieving cyclic cooling and improving the forming efficiency of the plastic tube.

[0034] Example 4: In order to solve the problems existing in the injection molding process of plastic pipes, this example discloses the following technical solution: the right end of the injection mold 4 is provided with an ejector mechanism, and the ejector mechanism includes an ejector sleeve 7, and the right end of the ejector sleeve 7 is fixedly installed with a transmission vertical plate 8; the ejector sleeve 7 included in the ejector mechanism is slidably sleeved on the outer wall of the filling rod 10, and the left end of the ejector sleeve 7 is inserted into the molding cavity 5 opened inside the injection mold 4, and the molding cavity 5 and the ejector sleeve 7 are combined to form a plastic pipe molding cavity, and the transmission vertical plate 8 at the right end of the ejector sleeve 7 is slidably disposed between the injection mold 4 and the positioning frame 11.

[0035] The ejector mechanism includes a main ejector side frame 17, which is fixedly installed on the front and rear sides of the right end of the transmission vertical plate 8. A secondary ejector side frame 18 is provided on the right end of the main ejector side frame 17 and is fixedly installed on the right side of the top surface of the injection molding machine body 1. In the initial state, the secondary ejector side frame 18 does not contact the main ejector side frame 17.

[0036] like Figures 7-9 As shown, after the plastic tube inside the injection mold 3 and the injection sliding mold 4 is formed, it is operated by the hydraulic cylinder 16 installed on the top of the protective cover 15. The telescopic part at the left end of the cylinder drives the fixedly connected injection sliding mold 4 to slide to the right along the direction of the guide slide rod 14. The formed plastic tube fills the forming cavity 5 inside the injection sliding mold 4, separating it from the injection mold 3. The injection sliding mold 4 drives the internal filling rod 10 and the ejector sleeve 7 to move synchronously. During the movement, the transmission vertical plate 8 at the right end of the ejector sleeve 7 and the main ejector side frame 17 come into contact with the auxiliary ejector side frame 18 at the top right end of the injection molding machine body 1. The fixedly installed auxiliary ejector side frame 18 abuts against the main ejector side frame 17 and the transmission vertical plate 8, so that the transmission vertical plate 8 and the ejector sleeve 7 at the left end are in a relatively stationary state relative to the injection mold 4.

[0037] Furthermore, during the continuous movement of the injection molding slip mold 4, the ejector sleeve 7 in its internal molding cavity 5 is in a stationary state. The left end of the ejector sleeve 7 abuts against the molded plastic tube, causing the plastic tube to slide to the left end of the molding cavity 5 so as to disengage from the injection molding slip mold 4. Then, it is collected and processed through the discharge port at the lower end of the injection molding machine body 1.

[0038] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An injection molding device for the production of plastic pipes, comprising an injection molding machine body (1), wherein a screw extrusion assembly (2) is provided above the left end of the injection molding machine body (1), and the screw extrusion assembly (2) extrudes and conveys the molten waste plastic material; Its features are, Also includes: A molding mechanism is provided on the upper right end of the injection molding machine body (1), and the molding mechanism includes an injection mold (3), and an injection sliding mold (4) is provided on the right end of the injection mold (3). Among them, the injection molding mold (4) has molding cavities (5) evenly spaced inside, and the left end of the adjacent molding cavity (5) has an injection flow channel (6). The injection molding slide mold (4) is provided with an ejector mechanism at the right end, and the ejector mechanism includes an ejector sleeve (7), and a transmission vertical plate (8) is fixedly installed at the right end of the ejector sleeve (7).

2. The injection molding device for producing plastic pipes according to claim 1, characterized in that: The molding mechanism includes an injection groove (9), which is located at the center of the injection mold (3). The left end of the injection mold (3) is connected to the screw extrusion assembly (2) to extrude the molten waste plastic into the injection groove (9) inside the injection mold (3). The injection groove (9) is also connected to the molding cavity (5).

3. The injection molding apparatus for producing plastic pipes according to claim 2, characterized in that: The molding mechanism includes a filling rod (10), and the left end of the filling rod (10) is inserted into the molding cavity (5) opened inside the injection mold (4). The filling rod (10) and the molding cavity (5) are distributed in a one-to-one correspondence. The filling rod (10) is located at the center of the molding cavity (5). At the same time, the molding cavity (5) and the injection flow channel (6) are interconnected.

4. The injection molding apparatus for producing plastic pipes according to claim 3, characterized in that: The molding mechanism includes a positioning frame (11), which is fixedly installed on the right outer wall of the injection molding mold (4). An extension rod (12) is fixedly installed at equal intervals on the left outer wall of the positioning frame (11). The left end of the extension rod (12) is fixedly connected to the right end of the filling rod (10). The filling rod (10) and the extension rod (12) slide synchronously with the injection molding mold (4).

5. The injection molding apparatus for producing plastic pipes according to claim 1, characterized in that: The molding mechanism includes a positioning tail plate (13), which is fixedly installed on the right side of the top surface of the injection molding machine body (1). The four corners of the positioning tail plate (13) are fixedly connected to the right end of the guide slide rod (14). The left end of the guide slide rod (14) extends to the left side of the top surface of the injection molding machine body (1), and the left end of the guide slide rod (14) is fixedly set inside the injection mold (3).

6. The injection molding apparatus for producing plastic pipes according to claim 5, characterized in that: The molding mechanism includes a protective cover (15), and the protective cover (15) is fixedly installed on the right side of the top surface of the injection molding machine body (1). A hydraulic cylinder (16) is fixedly installed at the center of the top surface of the protective cover (15). The telescopic part of the left end of the hydraulic cylinder (16) is fixedly connected to the top surface of the injection molding mold (4) by bolts. At the same time, the injection molding mold (4) is slidably sleeved on the outer wall of the guide slide rod (14).

7. The injection molding apparatus for producing plastic pipes according to claim 1, characterized in that: The ejector mechanism includes an ejector sleeve (7) which is slidably sleeved on the outer wall of the filling rod (10), and the left end of the ejector sleeve (7) is inserted into the molding cavity (5) opened inside the injection mold (4). The molding cavity (5) and the ejector sleeve (7) together form a plastic tube molding cavity. The transmission vertical plate (8) at the right end of the ejector sleeve (7) is slidably disposed between the injection mold (4) and the positioning frame (11).

8. The injection molding apparatus for producing plastic pipes according to claim 7, characterized in that: The ejector mechanism includes a main ejector side frame (17), which is fixedly installed on the front and rear sides of the right end of the transmission vertical plate (8). A secondary ejector side frame (18) is provided on the right end of the main ejector side frame (17), and the secondary ejector side frame (18) is fixedly installed on the right side of the top surface of the injection molding machine body (1). In the initial state, the secondary ejector side frame (18) does not contact the main ejector side frame (17).

9. The injection molding apparatus for producing plastic pipes according to claim 1, characterized in that: The top material mechanism includes a main circulation coil (19) and a secondary circulation coil (20), and both the main circulation coil (19) and the secondary circulation coil (20) are located on the left outer wall of the transmission vertical plate (8). Both the main circulation coil (19) and the secondary circulation coil (20) are arranged in an "S" shape around the outer wall of the top material sliding sleeve (7). The main circulation coil (19) and the secondary circulation coil (20) cool and mold the top material sliding sleeve (7) and the molten waste plastic at the end.

10. The injection molding apparatus for producing plastic pipes according to claim 9, characterized in that: The top material mechanism includes an input pipe (21) and an output pipe (22). The left end of the input pipe (21) is fixedly connected to one end of the main circulation coil (19) and the auxiliary circulation coil (20), and the left end of the output pipe (22) is fixedly connected to the other end of the main circulation coil (19) and the auxiliary circulation coil (20). The right ends of the input pipe (21) and the output pipe (22) are connected to a liquid-cooled pump box (23), which is fixedly installed on the inner wall of the positioning tail plate (13).

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