Secondary injection molding mold

Abstract

The invention relates to the technical field of secondary injection molds, in particular to a secondary injection molding mold which comprises a secondary switching rotary table, two molding bottom molds symmetrically and fixedly mounted on one side of the secondary switching rotary table and two molding upper molds arranged on one sides of the two molding bottom molds in an attached mode. According to the secondary injection molding mold, in the secondary molding operation of plastic waste recycling, viscous molding liquid on the inner wall of the liquid injection pipe can be automatically scraped off through cooperative arrangement of the cleaning assembly and the driving and discharging assembly, and in the upward scraping process of the connecting base, negative pressure is synchronously generated in the liquid collecting barrel on one side of the connecting base; viscous shaping liquid stacked at the top end of the connecting base after being scraped can be sucked and discharged, the problem that residual pain points difficult to remove are left on the inner wall of a liquid injection pipe in traditional cleaning is effectively solved, it is ensured that the inner wall of the liquid injection pipe is restored to be smooth, the scraped shaping liquid is thoroughly discharged, secondary pollution and blocking are avoided, and the service life of the liquid injection pipe is prolonged. And reliable support is provided for efficient and stable molding of plastic waste recycling.

Description

Technical Field

[0001] This invention relates to the field of secondary injection mold technology, specifically a secondary injection molding mold. Background Technology

[0002] Secondary injection molding dies are key equipment in the plastic waste recycling industry chain, providing core technical support for the resource transformation of recycled plastics. Plastic waste that has undergone crushing, washing, and granulation pretreatment needs to be melted, plasticized, and precisely molded through secondary injection molding dies to be transformed into various recycled plastic products.

[0003] The secondary injection molding mold achieves process conversion through a secondary switching turntable. It is equipped with two molding bottom molds and two molding top molds. Each of the two molding top molds has a liquid injection port on one side. During the first injection, one molding top mold and one molding bottom mold are closed to inject material to form a blank. Afterward, the secondary switching turntable rotates 180 degrees, and the blank is moved to the secondary station, so that the other molding top mold and molding bottom mold are closed, and a second material is injected to complete the composite molding.

[0004] The inner wall of the injection port of existing secondary injection molds is prone to adhesion residue due to long-term contact with viscous plastic liquid. The residue will gradually solidify after repeated accumulation during the molding cycle, and traditional cleaning methods are difficult to effectively deal with it. If manual scraping is used, the overall operation is quite troublesome and requires stopping the machine and disassembling the mold. Although some molds are equipped with simple scraping structures, they lack suction assistance functions. The scraped plastic liquid is easy to fall to the bottom of the injection port or the cavity connection, and cannot be completely discharged. It will still be carried into the cavity during subsequent injection, causing secondary pollution and blockage. Existing cleaning methods not only reduce production efficiency, but may also damage the inner wall of the injection port due to improper operation, aggravate the roughness of the inner wall, and ultimately shorten the service life of the mold, while affecting the stability of the quality of the molded parts. Summary of the Invention

[0005] The purpose of this invention is to provide a secondary injection molding mold to solve the problem mentioned in the background art: the inner wall of the injection port of existing secondary injection molds is prone to adhesion residue due to long-term contact with viscous plastic liquid. The residue gradually solidifies after repeated accumulation during the molding cycle, making it difficult to effectively handle with traditional cleaning methods. If manual scraping is used, the overall operation is quite troublesome, requiring machine shutdown and mold disassembly. Although some molds are equipped with simple scraping structures, they lack suction assistance functions, and the scraped plastic liquid easily falls to the bottom of the injection port or the cavity connection, which cannot be completely discharged. It will still be carried into the cavity during subsequent injection, causing secondary pollution and blockage. Existing cleaning methods not only reduce production efficiency, but may also damage the inner wall of the injection port due to improper operation, aggravating the roughness of the inner wall, ultimately leading to a shortened mold life and affecting the stability of the quality of the molded parts.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a secondary injection molding mold, comprising a secondary switching turntable, two molding bottom molds symmetrically fixedly installed on one side of the secondary switching turntable, and two molding upper molds fitted to one side of the two molding bottom molds. Each of the two molding upper molds has a molding cavity inside. A liquid injection pipe is fixedly installed through the side of each molding upper mold near the molding cavity. A cleaning component is installed inside the liquid injection pipe, and a drive discharge component is installed on the outside of one side of the liquid injection pipe. The cleaning component includes a cavity rod and a connecting seat. The cavity rod is disposed through the middle of the inside of the liquid injection pipe. The connecting seat is fixedly installed at the end of the cavity rod near the molding cavity. A plurality of return holes are circumferentially opened at equal angles around the bottom end of the connecting seat away from the cavity rod. A sealing switching component is installed on one side of each of the plurality of return holes.

[0007] Furthermore, a guide tube is horizontally and fixedly installed on one side of the injection tube near the top, and a threaded joint is installed at the end of the guide tube away from the injection tube, and the guide tube is threadedly sealed at one end of the threaded joint.

[0008] Furthermore, the drive discharge assembly includes a fixed base, an electric telescopic rod, and a collection cylinder. The fixed base is fixedly installed on the outside of one side of the injection pipe, the electric telescopic rod is vertically fixed on the outside of one side of the fixed base, the collection cylinder is vertically arranged on the outside of one side of the electric telescopic rod, a fixing frame is fixedly installed on one side of the fixed base, and one side of the collection cylinder is fixedly installed with the fixing frame.

[0009] Furthermore, a sealing cover is fixedly installed at the top of the injection tube, the top of the cavity rod is inserted through the middle of the top of the sealing cover, and an abutment is fixedly installed at the output end of the electric telescopic rod, with one end of the abutment fixedly installed through the outside of the top side of the cavity rod.

[0010] Furthermore, a piston block is slidably and sealed inside the bottom end of the liquid collecting cylinder, and a pull rod is vertically fixed at the top center of the piston block. The top end of the pull rod is fixedly connected to the other end of the contact frame. An inlet pipe is fixedly installed through the bottom end of the liquid collecting cylinder, and a one-way valve is installed through one side of the inlet pipe. A tension hose is fixedly connected to the input end of the inlet pipe.

[0011] Furthermore, a mounting block is fixedly installed at the top of the cavity rod, the input end of the stretching hose is fixedly installed inside the mounting block, a drain pipe is fixedly installed at the bottom end of the liquid collecting cylinder on the side away from the liquid inlet pipe, and a one-way valve is also installed on one side of the drain pipe.

[0012] Furthermore, the connecting seat is conical in shape, and a collection cavity is provided inside the connecting seat. The collection cavity is electrically connected to the inside of the hollow rod. A base plate is fixedly installed at the bottom of the connecting seat, and an annular airbag is sleeved and fitted onto the outside of the base plate. A heating element is fixedly attached to the outside of the connecting seat.

[0013] Furthermore, the blocking switching assembly includes a connecting pipe and a limiting seat. One end of the connecting pipe is conductively connected to and fixed to the return fluid hole. The limiting seat is vertically fixed to the outside of the bottom side of the connecting pipe. An installation cavity is opened inside the limiting seat, and a through hole is opened between the top of the installation cavity and the inside of the connecting pipe.

[0014] Furthermore, a sealing block is vertically and slidingly installed inside the through hole, and a sealing plug is fixedly installed at the bottom end of the sealing block. The sealing plug and the inner wall of the mounting cavity are vertically and slidingly connected. An air guide tube is provided on one side of the limiting seat, and one end of the air guide tube is fixedly installed inside the mounting cavity near the top of the sealing plug.

[0015] Furthermore, the other end of the air guide tube is fixedly installed inside one side of the annular airbag, and a compression spring is fixedly installed at the bottom end of the sealing plug, with the bottom end of the compression spring fixedly installed on the bottom wall of the mounting cavity.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. In the secondary molding operation of plastic waste recycling, this secondary injection molding mold, through the coordinated setting of the cleaning component and the drive discharge component, can automatically scrape off the viscous plastic liquid on the inner wall of the injection tube. During the upward scraping process of the connecting seat, a negative pressure is simultaneously generated inside the liquid collection cylinder on one side, which can suck in and discharge the viscous plastic liquid accumulated on the top of the connecting seat after scraping. This effectively solves the pain point of difficult-to-remove residue on the inner wall of the injection tube in traditional cleaning, ensuring that the inner wall of the injection tube is restored to smoothness and that the scraped plastic liquid is completely discharged, avoiding secondary pollution and blockage, and ensuring a stable and continuous molding process. Compared with traditional manual cleaning, the automated operation driven by the electric telescopic rod eliminates the need for manual disassembly and cleaning after machine shutdown, greatly reducing production interruption time, reducing reliance on manual labor, and improving overall production efficiency. At the same time, the conical setting of the connecting seat can make the plastic liquid flow more evenly during injection, avoiding impact damage to the inner wall of the injection tube, further extending the service life of the injection tube, and providing reliable support for the efficient and stable molding of plastic waste recycling.

[0017] 2. In the secondary molding operation of plastic waste recycling, this secondary injection molding mold achieves precise function switching by relying on the setting of the sealing and switching component, bringing a key guarantee effect. When the connecting seat rises to clean the injection tube, several return holes will open simultaneously to efficiently complete the back suction treatment of viscous plastic liquid. When the connecting seat descends and detaches from the injection tube, the return holes can automatically close. This automatic switching mechanism can effectively prevent the subsequently injected viscous plastic liquid from entering the return holes, prevent the problem of insufficient liquid volume, and effectively ensure the integrity of subsequent injection molding, providing reliable support for the stable secondary molding of plastic waste recycling. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a top view of the overall structure of the present invention; Figure 3 This is a partial cross-sectional three-dimensional structural diagram of the connecting seat and the molding cavity of the present invention; Figure 4 for Figure 3 Enlarged structural diagram at point A in the middle; Figure 5 This is a partial cross-sectional three-dimensional structural schematic diagram of the injection tube and the hollow rod of the present invention; Figure 6 For this Figure 5 Enlarged structural diagram at point B; Figure 7 This is a partial cross-sectional three-dimensional structural schematic diagram of the liquid collecting cylinder and piston block of the present invention; Figure 8 This is a partial cross-sectional perspective view of the three-dimensional structure of the connecting seat and the base plate of the present invention; Figure 9 For this Figure 8 Enlarged structural diagram at point C; Figure 10 This is a three-dimensional structural diagram of the sealing plug and compression spring of the present invention.

[0019] The attached diagram lists the components represented by each number as follows: 1. Secondary switching turntable; 2. Molding bottom mold; 3. Molding upper mold; 4. Injection pipe; 5. Molding cavity; 6. Conductor pipe; 7. Threaded joint; 8. Liquid guide pipe; 9. Fixing seat; 10. Electric telescopic rod; 11. Sealing cover plate; 12. Cavity rod; 13. Connecting seat; 14. Contact frame; 15. Fixing frame; 16. Liquid collection cylinder; 17. Liquid inlet pipe; 18. One-way valve; 19. Piston block; 20. Pull rod; 21. Tensioning hose; 22. Mounting block; 23. Collection cavity; 24. Base plate; 25. Liquid return hole; 26. Annular airbag; 27. Heating element; 28. Connecting pipe; 29. ​​Limiting seat; 30. Mounting cavity; 31. Sealing block; 32. Sealing plug; 33. Air guide pipe; 34. Compression spring; 35. Through hole; 36. Drain pipe. Detailed Implementation

[0020] 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.

[0021] Example 1: Please refer to Figure 1 - Figure 8 A secondary injection molding die includes a secondary switching turntable 1, two molding bottom molds 2 symmetrically fixedly installed on one side of the secondary switching turntable 1, and two molding upper molds 3 fitted to one side of the two molding bottom molds 2. Each molding upper mold 3 has a molding cavity 5 inside. Each molding upper mold 3 has an injection pipe 4 fixedly installed through it on the side near the molding cavity 5. The injection pipe 4 has a cleaning component inside it, and a drive discharge component is installed on the outside of one side of the injection pipe 4. The cleaning component includes a cavity rod 12 and a connecting seat 13. The cavity rod 12 is installed through it in the middle of the injection pipe 4. The connecting seat 13 is fixedly installed at the end of the cavity rod 12 near the molding cavity 5. The bottom end of the connecting seat 13 away from the cavity rod 12 has several return holes 25 that are opened around it at equal angles.

[0022] A guide tube 6 is horizontally fixedly installed on one side of the injection tube 4 near the top. A threaded connector 7 is installed on the end of the guide tube 6 away from the injection tube 4. A guide tube 8 is installed on one end of the threaded connector 7 with a threaded seal.

[0023] The drive discharge assembly includes a fixed base 9, an electric telescopic rod 10, and a collection cylinder 16. The fixed base 9 is fixedly installed on the outside of one side of the injection pipe 4. The electric telescopic rod 10 is vertically fixed on the outside of one side of the fixed base 9. The collection cylinder 16 is vertically installed on the outside of one side of the electric telescopic rod 10. A fixing frame 15 is fixedly installed on one side of the fixed base 9. One side of the collection cylinder 16 is fixedly installed with the fixing frame 15.

[0024] A sealing cover plate 11 is fixedly installed at the top of the injection tube 4. The top of the cavity rod 12 is inserted through the middle of the top of the sealing cover plate 11. A contact frame 14 is fixedly installed at the output end of the electric telescopic rod 10. One end of the contact frame 14 is inserted through and fixedly installed on the outside of the top side of the cavity rod 12.

[0025] A piston block 19 is slidably and sealed inside the bottom end of the liquid collecting cylinder 16. A pull rod 20 is vertically fixed at the top center of the piston block 19. The top end of the pull rod 20 is fixedly connected to the other end of the contact frame 14. An inlet pipe 17 is fixedly installed through the bottom end of the liquid collecting cylinder 16. A one-way valve 18 is installed through one side of the inlet pipe 17. A tension hose 21 is fixedly connected to the input end of the inlet pipe 17.

[0026] A mounting block 22 is fixedly installed at the top of the cavity rod 12. The input end of the stretching hose 21 is fixedly installed inside the mounting block 22. A drain pipe 36 is fixedly installed at the bottom of the liquid collecting cylinder 16 on the side away from the liquid inlet pipe 17. A one-way valve 18 is also installed on one side of the drain pipe 36.

[0027] The connecting seat 13 is conical in shape. A collection cavity 23 is provided inside the connecting seat 13. The collection cavity 23 is electrically connected to the cavity rod 12. A base plate 24 is fixedly installed at the bottom of the connecting seat 13. An annular airbag 26 is fitted and installed on the outside of the base plate 24. A heating element 27 is fixedly attached to the outside of the connecting seat 13.

[0028] Specifically, the connector 13 is designed in a conical shape, which allows the plastic liquid to flow more evenly during injection, avoids impact damage to the inner wall of the injection tube 4, further extends the service life of the injection tube 4, and provides reliable support for the efficient and stable molding of plastic waste recycling.

[0029] In this embodiment, when the mold is used for the first injection (or the second compound injection), the existing structure of the secondary switching turntable 1 drives the corresponding molding bottom mold 2 and molding upper mold 3 to close, forming a closed molding cavity 5. The external plastic liquid (including recycled plastic melt) is transported through the liquid guide pipe 8 and enters the injection pipe 4 through the threaded joint 7 and the guide pipe 6. At this time, the connecting seat 13 is located at the bottom of the injection pipe 4. Its conical structure can guide the plastic liquid to flow evenly along the inner wall, avoiding the liquid flow impacting the inner wall of the injection pipe 4 and causing wear. At the same time, it ensures that the plastic liquid is injected smoothly into the molding cavity 5 to complete the shaping of the initial blank (or compound molded part).

[0030] After a single injection molding process is completed, viscous molding liquid residue will adhere to the inner wall of injection tube 4, requiring the initiation of a cleaning procedure: First, the electric telescopic rod 10 is powered on and its output end extends upward, driving the fixedly connected contact frame 14 to rise synchronously. One end of the contact frame 14 is fixed to the outside of the top of the cavity rod 12, thus driving the cavity rod 12 to move upward along the through hole of the sealing cover plate 11. This, in turn, pulls the connecting seat 13 at the bottom of the cavity rod 12 to slide upward inside the injection tube 4. The outer wall of the connecting seat 13 is tightly attached to the inner wall of the injection tube 4. During the upward sliding process, the sticky plastic liquid residue on the inner wall of the injection tube 4 is directly scraped off, effectively solving the pain point of difficult removal of residue on the inner wall of the injection tube 4 in traditional cleaning, and ensuring that the inner wall of the injection tube 4 is restored to smoothness.

[0031] Meanwhile, the other end of the contact frame 14 is fixedly connected to the top of the pull rod 20. When the contact frame 14 rises, it synchronously pulls the pull rod 20 and the piston block 19 to slide upward inside the liquid collecting cylinder 16. When the piston block 19 moves upward, it creates a negative pressure inside the liquid collecting cylinder 16. This negative pressure is transmitted to the cavity rod 12 through the inlet pipe 17, the one-way valve 18, the stretching hose 21, and the mounting block 22. The cavity rod 12 is connected to the collection chamber 23 inside the connecting seat 13. The collection chamber 23 is connected to the inside of the injection pipe 4 through the return hole 25, ultimately connecting the connecting seat. The residual molding liquid scraped off by 13 is sucked into the collection chamber 23. At the same time, the heating plate 27 surrounding the outside of the connecting seat 13 is energized and heats up to heat the scraped viscous molding liquid, preventing it from adhering to the inner or outer wall of the connecting seat 13, improving the flowability of the molding liquid, and ensuring that the residual molding liquid can smoothly enter the collection chamber 23 through the return hole 25, and then enter the collection cylinder 16 for temporary storage through the cavity rod 12, the stretching hose 21 and the inlet pipe 17, so as to completely discharge the scraped molding liquid, avoid secondary pollution and blockage, and ensure the stable and continuous molding process.

[0032] After cleaning, the residual plasticizing liquid temporarily stored in the collection cylinder 16 needs to be recycled to an external storage tank for reuse. At this time, the output end of the electric telescopic rod 10 retracts downward, causing the contact frame 14 to descend synchronously, which in turn causes the pull rod 20 and piston block 19 to slide downward in the liquid collection cylinder 16. The piston block 19 squeezes the plastic liquid in the liquid collection cylinder 16 downward, so that the plastic liquid is discharged into the existing plastic liquid tank outside through the drain pipe 36 and the one-way valve 18, completing the recycling and reuse of the residue.

[0033] Meanwhile, compared to traditional manual cleaning, this secondary injection molding mold relies on the automated operation driven by the electric telescopic rod 10, eliminating the need for manual disassembly and cleaning after machine shutdown, greatly reducing production downtime, reducing reliance on manual labor while improving overall production efficiency.

[0034] As the contact frame 14 descends, it drives the cavity rod 12 and the connecting seat 13 to slide down and reset along the inner wall of the injection pipe 4, returning to the initial position at the bottom of the injection pipe 4, so that the injection pipe 4 is connected to the molding cavity 5, preparing for the next injection and molding.

[0035] Example 2: Please refer to Figure 8 - Figure 10 This embodiment further illustrates Example 1, wherein a blocking switching component is provided on one side of each of the plurality of return holes 25.

[0036] The blocking and switching assembly includes a connecting pipe 28 and a limiting seat 29. One end of the connecting pipe 28 is connected to and fixed to the return hole 25. The limiting seat 29 is vertically fixed to the outside of the bottom side of the connecting pipe 28. An installation cavity 30 is opened inside the limiting seat 29. A through hole 35 is opened between the top of the installation cavity 30 and the inside of the connecting pipe 28.

[0037] A sealing block 31 is vertically and slidingly installed inside the through hole 35. A sealing plug 32 is fixedly installed at the bottom end of the sealing block 31. The sealing plug 32 and the inner wall of the mounting cavity 30 are vertically and slidingly connected. A vent pipe 33 is provided on one side of the limiting seat 29. One end of the vent pipe 33 is fixedly installed inside the mounting cavity 30 near the top of the sealing plug 32.

[0038] The other end of the air duct 33 is fixedly installed inside one side of the annular airbag 26. A compression spring 34 is fixedly installed at the bottom end of the sealing plug 32. The bottom end of the compression spring 34 is fixedly installed on the bottom wall of the mounting cavity 30.

[0039] In this embodiment, when the electric telescopic rod 10 drives the contact frame 14 to rise, causing the cavity rod 12 and connecting seat 13 to slide upward within the injection tube 4, the annular airbag 26 is squeezed by the inner wall of the injection tube 4, reducing the internal space of the annular airbag 26. The compressed gas is then transported through the air guide tube 33 to the sealed space within the mounting cavity 30. Subsequently, the air pressure at the top of the sealing plug 32 within the mounting cavity 30 gradually increases with gas injection. When the air pressure gradually overcomes the elastic force of the compression spring 34 at the bottom of the sealing plug 32, the sealed space... The plug 32 slides vertically downward along the inner wall of the mounting cavity 30. The downward movement of the plug 32 will cause the sealing block 31 to exit from the through hole 35 simultaneously, releasing the seal on the connecting pipe 28. At this time, the return hole 25 is fully open. With the rise of the piston block 19 in the negative pressure suction collection cylinder 16 of Embodiment 1, a negative pressure is generated. The viscous plastic liquid scraped off by the connecting seat 13 can pass smoothly through the return hole 25, the connecting pipe 28, the collection cavity 23, and the hollow rod 12, and is finally sucked into the collection cylinder 16, ensuring that the residual recovery is unimpeded.

[0040] When cleaning is complete, the electric telescopic rod 10 drives the contact frame 14 to descend, causing the cavity rod 12 and connecting seat 13 to slide downwards and reset along the inner wall of the injection tube 4. At this time, the annular airbag 26 gradually detaches from the pressure of the inner wall of the injection tube 4 and returns to its original shape under its own elasticity. The internal space expands, creating negative pressure. At this time, the gas at the top of the sealing plug 32 in the installation cavity 30 flows back to the annular airbag 26 through the air guide tube 33, causing the air pressure at the top of the sealing plug 32 to drop. When the air pressure at the top of the sealing plug 32 is insufficient to resist... When the elastic force of the compression spring 34 is released, the spring 34 releases its elastic force, pushing the sealing plug 32 upwards along the inner wall of the mounting cavity 30. The sealing plug 32 drives the sealing block 31 at the top to rise synchronously and re-insert into the through hole 35. The sealing block 31 and the inner wall of the through hole 35 are in a sliding seal fit. After insertion, the connection between the connecting pipe 28 and the mounting cavity 30 is completely blocked. The connecting pipe 28 cannot conduct because the through hole 35 is blocked by the sealing block 31, and the return hole 25 connected to the connecting pipe 28 is closed accordingly. At this time, when the external molding liquid is injected into the injection pipe 4 through the liquid guide pipe 8 and the connecting pipe 6, it cannot enter the collection cavity 23 or the cavity rod 12 through the return hole 25. This ensures that all the liquid volume injected in the metered injection flows to the molding cavity 5, avoiding incomplete molding parts due to insufficient liquid volume, and providing reliable support for efficient and stable molding of plastic waste recycling.

[0041] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0042] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A secondary injection molding die, comprising a secondary switching turntable (1), two molding bottom molds (2) symmetrically fixedly installed on one side of the secondary switching turntable (1), and two molding upper molds (3) fitted onto one side of the two molding bottom molds (2), characterized in that: Both of the molding upper molds (3) are provided with molding cavities (5). Each molding upper mold (3) is fixedly installed with a liquid injection pipe (4) on the side near the molding cavity (5). The liquid injection pipe (4) is provided with a cleaning component inside and a drive discharge component is provided on the outside of one side of the liquid injection pipe (4). The cleaning assembly includes a cavity rod (12) and a connecting seat (13). The cavity rod (12) is disposed through the middle of the inside of the injection tube (4). The connecting seat (13) is fixedly installed at one end of the cavity rod (12) near the molding cavity (5). A plurality of return holes (25) are provided at equal angles around the bottom end of the connecting seat (13) away from the cavity rod (12). A sealing switching assembly is provided on one side of each of the plurality of return holes (25).

2. The secondary injection molding die according to claim 1, characterized in that: A guide tube (6) is horizontally fixedly installed on one side of the injection tube (4) near the top. A threaded connector (7) is installed at the end of the guide tube (6) away from the injection tube (4). A guide tube (8) is threadedly sealed at one end of the threaded connector (7).

3. The secondary injection molding die according to claim 1, characterized in that: The drive discharge assembly includes a fixed base (9), an electric telescopic rod (10), and a collection cylinder (16). The fixed base (9) is fixedly installed on the outside of one side of the injection pipe (4). The electric telescopic rod (10) is vertically fixed on the outside of one side of the fixed base (9). The collection cylinder (16) is vertically arranged on the outside of one side of the electric telescopic rod (10). A fixing frame (15) is fixedly installed on one side of the fixed base (9). One side of the collection cylinder (16) is fixedly installed with the fixing frame (15).

4. A secondary injection molding die according to claim 3, characterized in that: A sealing cover plate (11) is fixedly installed at the top end of the injection tube (4), and the top end of the cavity rod (12) is disposed through the middle of the top end of the sealing cover plate (11). A contact frame (14) is fixedly installed at the output end of the electric telescopic rod (10), and one end of the contact frame (14) is fixedly installed through the outside of the top end of the cavity rod (12).

5. A secondary injection molding die according to claim 4, characterized in that: A piston block (19) is slidably and sealed inside the bottom end of the liquid collecting cylinder (16). A pull rod (20) is vertically fixed at the top center of the piston block (19). The top end of the pull rod (20) is fixedly connected to the other end of the contact frame (14). An inlet pipe (17) is fixedly installed through the bottom end of the liquid collecting cylinder (16). A one-way valve (18) is installed through one side of the inlet pipe (17). A tension hose (21) is fixedly connected to the input end of the inlet pipe (17).

6. A secondary injection molding die according to claim 5, characterized in that: The top end of the cavity rod (12) is fixedly installed with an installation block (22), the input end of the stretching hose (21) is fixedly installed inside the installation block (22), the bottom end of the liquid collecting cylinder (16) away from the liquid inlet pipe (17) is fixedly installed with a drain pipe (36), and a one-way valve (18) is also installed on one side of the drain pipe (36).

7. A secondary injection molding die according to claim 1, characterized in that: The connecting seat (13) is conical in shape. A collection cavity (23) is provided inside the connecting seat (13). The collection cavity (23) is connected to the cavity rod (12). A base plate (24) is fixedly installed at the bottom of the connecting seat (13). An annular airbag (26) is fitted and installed on the outside of the base plate (24). A heating element (27) is fixedly attached to the outside of the connecting seat (13).

8. A secondary injection molding die according to claim 7, characterized in that: The blocking switching assembly includes a connecting pipe (28) and a limiting seat (29). The connecting pipe (28) is connected and fixed to one end of the return hole (25). The limiting seat (29) is vertically fixed to the outside of the bottom side of the connecting pipe (28). An installation cavity (30) is opened inside the limiting seat (29). A through hole (35) is opened between the top of the installation cavity (30) and the inside of the connecting pipe (28).

9. A secondary injection molding die according to claim 8, characterized in that: A sealing block (31) is vertically and slidingly installed inside the through hole (35). A sealing plug (32) is fixedly installed at the bottom end of the sealing block (31). The sealing plug (32) and the inner wall of the mounting cavity (30) are vertically and slidingly connected. A duct (33) is provided on one side of the limiting seat (29). One end of the duct (33) is fixedly installed inside the mounting cavity (30) near the top of the sealing plug (32).

10. A secondary injection molding die according to claim 9, characterized in that: The other end of the air guide tube (33) is fixedly installed inside one side of the annular airbag (26), and a compression spring (34) is fixedly installed at the bottom end of the sealing plug (32). The bottom end of the compression spring (34) is fixedly installed on the bottom wall of the mounting cavity (30).

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