Injection mold hot runner backflow turning point glue feeding forming structure

Abstract

The invention relates to the technical field of injection molding, in particular to an injection mold hot runner backflow turning point glue feeding molding structure. The plugging rod is arranged in the conveying pipe, and the upper end of the plugging rod is arranged in a through opening in the upper end of the conveying pipe; the movable plate is suspended on the upper side of the mounting plate, the movable plate movably penetrates through a through opening in the conveying pipe, the upper end of the plugging rod is inserted into the movable plate, and the movable plate is connected with the conveying pipe through a driving mechanism; the movable pipes are fixed to the two sides of the lower surface of the movable plate in a bilateral symmetry mode, the movable pipes are inserted into the mounting plate, and the lower ends of the movable pipes are located in cylindrical grooves in the mounting plate. The pushing rod is movably arranged in the plugging rod, and the outer ring wall of the pushing rod abuts against the interior of the plugging rod in a matched mode. The pushing mechanisms are symmetrically arranged in the movable plate left and right, and the pushing mechanisms are connected with the plugging rods and the adjacent movable pipes; and through cooperative action of the plugging rod and the pushing rod, the glue feeding amount is accurately controlled, backward flowing and accumulation of materials are prevented, and the molding quality and stability of injection molding products are improved.

Description

Technical Field

[0001] The invention relates to the technical field of injection molding, and in particular to a hot runner backflow turning point glue inlet molding structure of an injection mold. Background Art

[0002] In hot runner systems for injection molds, backflow injection is a common molding method used to control the flow and filling of molten plastic. Traditional hot runner structures are prone to product defects such as flow marks, sink marks, or uneven filling due to material accumulation or backflow during the injection molding process, affecting molding quality. Furthermore, the sealing mechanism in existing technologies typically uses a single valve needle control, which makes it difficult to accurately adjust the amount of glue fed. Furthermore, in high-temperature and high-pressure environments, problems such as poor sealing or delayed operation are prone to occur, leading to material leakage or unstable molding. Summary of the Invention

[0003] The purpose of the present invention is to address the defects and shortcomings of the existing technology and provide a reasonably designed and easy-to-use injection mold hot runner backflow turning point glue feeding molding structure. Through the coordinated action of the blocking rod and the push rod, the glue feeding amount can be accurately controlled to prevent material backflow and accumulation, thereby improving the molding quality and stability of the injection molded products.

[0004] To achieve the above-mentioned object, the present invention adopts the following technical solution: it comprises a conveying pipe and a mounting plate, wherein heating rings are embedded in the ring wall of the conveying pipe at equal intervals, and the mounting plate is sleeved and fixed on the outer side of the conveying pipe; it also comprises: The blocking rod is arranged inside the delivery pipe, the lower end of the blocking rod is matched and abutted against the outlet end of the delivery pipe, and the upper end of the blocking rod is in the through-hole at the upper end of the delivery pipe; A movable plate, the movable plate being suspended on the upper side of the mounting plate, the movable plate being movable and penetrating into the through-hole on the delivery pipe, the upper end of the blocking rod being inserted into the movable plate, and the movable plate being connected to the delivery pipe through a driving mechanism; There are two movable tubes, which are fixed symmetrically on both sides of the lower surface of the movable plate. The movable tubes are inserted into the mounting plate, and the lower ends of the movable tubes are located in the cylindrical groove inside the mounting plate; A push rod, wherein the push rod is movably arranged in the blocking rod, and the outer ring wall of the push rod is arranged to cooperate with and interfere with the inner wall of the blocking rod; There are two pushing mechanisms, which are symmetrically arranged in the movable plate. The pushing mechanisms are connected to the blocking rod and the adjacent movable tube; Through the above technical solution, the pushing mechanism on the appropriate side is opened, and when the conveying pipe is conveying materials, the blocking rod is located on the upper side of the discharge port of the conveying pipe, thereby not affecting the conveying of materials. After an appropriate amount of material enters the mold, the movable plate is driven downward by the driving mechanism, and the movable plate drives the blocking rod downward to block the discharge port of the conveying pipe. At the same time, the movable plate drives the movable pipe downward, and the movable pipe drives the push rod downward through the pushing mechanism inside the mounting plate, so that the push rod moves downward, so that the push rod pushes the materials accumulated at the discharge port of the conveying pipe, thereby improving the quality of the injection molded products.

[0005] As a further improvement of the present invention, the driving mechanism comprises: There are two drive discs, which are symmetrically arranged on the two inner walls of the through-hole of the conveying pipe. The protrusions on the drive discs are screwed into the conveying pipe through bearings. The drive shaft is screwed to the upper end of the conveying pipe through a bearing, and both ends of the drive shaft are connected to the protrusions on both sides of the drive disc through a synchronous wheel transmission assembly; A drive motor, wherein the drive motor is embedded in and fixed to the top wall of the delivery pipe, and the output shaft of the drive motor is connected to the middle end of the drive shaft through a bevel gear pair; There are two toggle rods, each of which is eccentrically fixed on a side wall of the driving disk adjacent to the movable plate, and the toggle rods are movably inserted into the waist-shaped holes on the movable plate; Through the above technical solution, the drive motor is started, and the drive motor drives the drive shaft to rotate through the bevel gear pair. The two ends of the drive shaft respectively drive the corresponding drive disk to rotate through the synchronous wheel transmission assembly, and the toggle rod on the drive disk drives the movable plate to move.

[0006] As a further improvement of the present invention, the movable plate is located on the lower side wall of one side inside the conveying pipe and is penetrated by a guide rod, and the upper and lower ends of the guide rod are respectively fixed to the upper and lower inner walls of the through-opening of the conveying pipe; The above technical solution can increase the stability of the movable plate when it moves up and down.

[0007] As a further improvement of the present invention, the pushing mechanism comprises: A connecting rod is movably inserted into the movable tube, a piston plate is fixed to the lower end of the connecting rod, and the outer ring wall of the piston plate is arranged to abut against the inner ring wall of the cylindrical groove; The limit blocks are multiple and fixed at equal angles on the outer ring wall of the connecting rod at one end inside the movable tube. The limit blocks are slidably arranged in the slide groove on the inner ring wall of the movable tube. The ventilation sleeve is arranged in an "L" shape. The ventilation sleeve is symmetrically arranged in the delivery pipe. The horizontal pipe of the ventilation sleeve passes through the annular wall of the delivery pipe and is inserted into the mounting plate. The ventilation sleeve is connected to the cylindrical groove and a control valve is built into the horizontal pipe of the ventilation sleeve. The ventilation cannula is arranged in an inverted "L" shape, the vertical tube of the ventilation cannula is movably inserted into the vertical tube of the ventilation sleeve, and the horizontal tube of the ventilation cannula is inserted through the blocking rod; Through the above technical solution, when the movable tube moves downward, it drives the piston plate to move downward, so that the gas in the cylindrical groove enters the blocking rod through the ventilation sleeve and the ventilation cannula. At this time, the air pressure pushes the push rod, thereby causing the push rod to move downward. When the piston plate moves upward, the air pressure formed between the cylindrical groove, the ventilation sleeve and the ventilation cannula changes, thereby driving the push rod to move upward.

[0008] As a further improvement of the present invention, a sealing ring is sleeved on the outer ring wall of the vertical tube of the ventilation cannula, and the outer ring wall of the sealing ring is matched and abutted against the inner ring wall of the vertical tube of the ventilation cannula; The above technical solution can improve the sealing between the ventilation sleeve and the ventilation cannula.

[0009] As a further improvement of the present invention, a square block is fixed on the top wall of the piston plate, the square block is inserted into the connecting rod, a circular groove is provided on the lower surface of the piston plate, a mounting mechanism is provided in the circular groove, and the mounting mechanism is connected to the connecting rod; Through the above technical solution, when the piston plate is worn, the installation mechanism is loosened to separate the square block from the connecting rod, and then a new piston plate is replaced, which is convenient for use.

[0010] As a further improvement of the present invention, the mounting mechanism comprises: Mounting blocks, there are two mounting blocks, and they are symmetrically arranged in the square block. One side of the mounting block passes through the square block and is inserted into the limit groove on the inner wall of the connecting rod. A connecting spring is fixed on the other side wall of the mounting block, and the connecting spring is fixed to the inner wall of the square block; A push block is arranged in the square block, a pull rod is fixed on the lower side wall of the push block, and the lower end of the pull rod passes through the piston plate and is located in the circular groove; A return spring is sleeved on one end of the pull rod located inside the square block, and both ends of the return spring are fixedly connected to the push block and the inner wall of the square block respectively; Through the above technical solution, when replacing the piston plate, pull the pull rod downward, and the pull rod drives the push block to move downward, so that the reset spring is compressed. At this time, the connecting spring drives the mounting block to retract into the square block, so that the piston plate can be removed. After replacing the new piston plate, the pull rod can be loosened, and the pull rod moves to one side of the mounting block under the elastic force of the reset spring, so that the push block pushes the mounting block, so that the mounting block is inserted into the connecting rod to achieve the limiting effect.

[0011] As a further improvement of the present invention, a grip is fixed to the lower end of the pull rod, and the grip is located in the circular groove; the pull rod can be easily pulled, and the operation is convenient.

[0012] As a further improvement of the present invention, a circular hole is provided on the bottom wall of the mounting plate and is communicated with the cylindrical groove. A sealing cover is screwed into the circular hole through a thread, and a circular plate on the lower side of the sealing cover is arranged to abut against the lower side wall of the mounting plate. With the above technical solution, after the piston plate is worn, the sealing cover can be unscrewed, thereby facilitating replacement of the piston plate.

[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. Through the linkage design of the blocking rod and the push rod, the melt flow is accurately controlled to prevent backflow and accumulation at the outlet, thereby improving the molding quality of injection molding products; 2. The motor-driven synchronous wheel transmission mechanism, combined with the guide rod and movable plate, ensures smooth and accurate sealing action and reduces mechanical vibration and wear; 3. Using the air pressure transmission of the movable tube and the ventilation sleeve, the push rod automatically cleans the residual material at the discharge port to avoid the accumulation of cold materials and improve production efficiency; 4. The piston plate adopts a quick-release structure and is equipped with a detachable sealing cover to facilitate the replacement of worn parts, reduce maintenance costs, and extend the service life of the mold. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the present invention.

[0015] Figure 2 It is a schematic diagram of the internal structure of the present invention.

[0016] Figure 3 for Figure 2 Enlarged view of part A in the middle.

[0017] Figure 4 for Figure 2 Enlarged view of part B in the middle.

[0018] Figure 5 It is an exploded view of the driving mechanism in the present invention.

[0019] Figure 6 It is an exploded view of the propulsion mechanism in the present invention.

[0020] Figure 7 This is an exploded view of the piston plate, connecting rod and mounting mechanism in the present invention.

[0021] Figure 8 for Figure 7 Enlarged view of part C in the middle.

[0022] Description of reference numerals: Feed pipe 1, mounting plate 2, blocking rod 3, movable plate 4, driving mechanism 5, driving disc 5-1, driving shaft 5-2, driving motor 5-3, toggle rod 5-4, movable tube 6, pushing rod 7, pushing mechanism 8, connecting rod 8-1, piston plate 8-2, limiting block 8-3, ventilation sleeve 8-4, ventilation cannula 8-5, guide rod 9, sealing ring 10, square block 11, mounting mechanism 12, mounting block 12-1, connecting spring 12-2, pushing block 12-3, pull rod 12-4, reset spring 12-5, gripping rod 13, sealing cover 14. DETAILED DESCRIPTION

[0023] The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. The preferred embodiments described are only used as examples. All other embodiments obtained by those skilled in the art without making any creative work are within the scope of protection of the present invention. Example 1

[0024] like Figures 1-8 As shown, this embodiment includes a feed pipe 1 and a mounting plate 2. Heating rings are equidistantly embedded in the ring wall of the feed pipe 1, and the mounting plate 2 is sleeved and fixed on the outer side of the feed pipe 1. It also includes: The blocking rod 3 is arranged inside the delivery pipe 1, the lower end of the blocking rod 3 is matched and abutted against the outlet end of the delivery pipe 1, and the upper end of the blocking rod 3 is in the through opening at the upper end of the delivery pipe 1; The movable plate 4 is suspended on the upper side of the mounting plate 2. The movable plate 4 is movable and passes through the through-hole on the delivery pipe 1. The upper end of the blocking rod 3 is inserted into the movable plate 4. The movable plate 4 is connected to the delivery pipe 1 through the driving mechanism 5. The movable plate 4 is located on the lower side wall of one side inside the delivery pipe 1 and is penetrated by a guide rod 9. The upper and lower ends of the guide rod 9 are respectively fixed to the upper and lower inner walls of the through-hole of the delivery pipe 1, which can increase the stability of the movable plate 4 when it moves up and down; There are two movable tubes 6, which are symmetrically welded and fixed on both sides of the lower surface of the movable plate 4. The movable tubes 6 are inserted into the mounting plate 2, and the lower ends of the movable tubes 6 are located in the cylindrical groove inside the mounting plate 2; The push rod 7 is movably arranged in the blocking rod 3, and the outer ring wall of the push rod 7 is matched and abutted against the inner wall of the blocking rod 3; The pushing mechanism 8 is two and is symmetrically arranged in the movable plate 4 . The pushing mechanism 8 is connected to the blocking rod 3 and the adjacent movable tube 6 . Example 2

[0025] See Figure 2 、 Figure 5 As shown, based on Example 1, the driving mechanism 5 includes: There are two drive discs 5-1, and they are symmetrically arranged on the two inner walls of the through-opening of the delivery pipe 1. The protrusions on the drive discs 5-1 are screwed into the delivery pipe 1 through bearings; The drive shaft 5-2 is screwed to the upper end of the conveying pipe 1 through a bearing, and both ends of the drive shaft 5-2 are connected to the protrusions on both sides of the drive disc 5-1 through synchronous wheel transmission assemblies; The drive motor 5-3 is embedded in and fixed to the top wall of the delivery pipe 1, and the output shaft of the drive motor 5-3 is connected to the middle end of the drive shaft 5-2 through a bevel gear pair; There are two toggle rods 5-4, which are eccentrically welded and fixed on one side wall of the driving disk 5-1 adjacent to the movable plate 4. The toggle rods 5-4 are movably inserted into the waist-shaped holes on the movable plate 4. Example 3

[0026] See Figure 2 、 Figure 6-8 As shown, based on Example 1, the pushing mechanism 8 includes: Connecting rod 8-1, the connecting rod 8-1 is movably inserted in the movable tube 6, the lower end of the connecting rod 8-1 is fixed with a piston plate 8-2, the outer ring wall of the piston plate 8-2 is set in conflict with the inner ring wall of the cylindrical groove; a square block 11 is welded and fixed on the top wall of the piston plate 8-2, the square block 11 is inserted in the connecting rod 8-1, a circular groove is provided on the lower surface of the piston plate 8-2, a mounting mechanism 12 is provided in the circular groove, the mounting mechanism 12 is connected to the connecting rod 8-1, when the piston plate 8-2 is worn, the mounting mechanism 12 is loosened, the square block 11 is separated from the connecting rod 8-1, and then a new piston plate 8-2 is replaced for easy use; The limit blocks 8-3 are several in number and are welded at equal angles to the outer ring wall of the connecting rod 8-1 at one end inside the movable tube 6. The limit blocks 8-3 are slidably arranged in the slide groove on the inner ring wall of the movable tube 6. The ventilation sleeve 8-4 is arranged in an "L" shape. The ventilation sleeve 8-4 is symmetrically arranged in the delivery pipe 1. After the horizontal pipe of the ventilation sleeve 8-4 passes through the annular wall of the delivery pipe 1, it is inserted into the mounting plate 2. The ventilation sleeve 8-4 is arranged to be connected with the cylindrical groove. The horizontal pipe of the ventilation sleeve 8-4 has a built-in control valve; The ventilation cannula 8-5 is arranged in an inverted "L" shape, the vertical tube of the ventilation cannula 8-5 is movably inserted in the vertical tube of the ventilation sleeve 8-4, and the horizontal tube of the ventilation cannula 8-5 is inserted through the blocking rod 3; a sealing ring 10 is sleeved on the outer ring wall of the vertical tube of the ventilation cannula 8-5, and the outer ring wall of the sealing ring 10 is matched with the inner ring wall of the vertical tube of the ventilation sleeve 8-4 to increase the sealing between the ventilation sleeve 8-4 and the ventilation cannula 8-5. Example 4

[0027] See Figure 7-8 As shown, based on Example 1, the mounting mechanism 12 includes: Mounting blocks 12-1, there are two mounting blocks 12-1, and they are symmetrically arranged in the square block 11. After one side of the mounting block 12-1 passes through the square block 11, it is inserted into the limit groove on the inner wall of the connecting rod 8-1. A connecting spring 12-2 is welded and fixed to the other side wall of the mounting block 12-1, and the connecting spring 12-2 is welded and fixed to the inner wall of the square block 11; The pushing block 12-3 is arranged in the square block 11, and a pull rod 12-4 is welded and fixed on the lower side wall of the pushing block 12-3. After the lower end of the pull rod 12-4 passes through the piston plate 8-2, it is located in the circular groove; the lower end of the pull rod 12-4 is welded and fixed with a grip rod 13, and the grip rod 13 is located in the circular groove; it is convenient to pull the pull rod 12-4, and the operation is convenient; a circular hole that penetrates the cylindrical groove is provided on the bottom wall of the mounting plate 2, and a sealing cover 14 is screwed into the circular hole by a thread, and the circular plate on the lower side of the sealing cover 14 is arranged to conflict with the lower side wall of the mounting plate 2. After the piston plate 8-2 is worn, the sealing cover 14 can be unscrewed, thereby facilitating the replacement of the piston plate 8-2; The reset spring 12-5 is sleeved on one end of the pull rod 12-4 located inside the square block 11, and the two ends of the reset spring 12-5 are respectively welded and fixed to the push block 12-3 and the inner wall of the square block 11.

[0028] When using the present invention, when the movable tube 6 moves downward, it drives the piston plate 8-2 to move downward, so that the gas in the cylindrical groove enters the blocking rod 3 through the ventilation sleeve 8-4 and the ventilation cannula 8-5. At this time, the air pressure pushes the push rod 7, thereby causing the push rod 7 to move downward. When the piston plate 8-2 moves upward, the air pressure formed between the cylindrical groove, the ventilation sleeve 8-4 and the ventilation cannula 8-5 changes, which drives the push rod 7 to move upward. When the conveying pipe 1 is conveying materials, the blocking rod 3 is located on the upper side of the discharge port of the conveying pipe 1, thereby not affecting the conveying of materials. After an appropriate amount of material enters the mold, the driving motor 5-3 is started, and the driving motor 5-3 drives the driving shaft 5-2 to rotate through the bevel gear pair. The two ends of the driving shaft 5-2 respectively drive the corresponding driving disc 5-1 to rotate through the synchronous wheel transmission assembly. The toggle rod 5-4 on the driving disc 5-1 drives the movable plate 4 to move, and the movable plate 4 drives the blocking rod 3 to move downward. The sealing rod 3 blocks the discharge port of the conveying pipe 1, and the movable plate 4 drives the movable pipe 6 to move downward. The movable pipe 6 drives the pushing rod 7 to move downward through the pushing mechanism 8 inside the mounting plate 2, so that the pushing rod 7 moves downward, so that the pushing rod 7 pushes the materials accumulated at the discharge port of the conveying pipe 1, thereby improving the quality of the injection molded products. When replacing the piston plate 8-2, the pull rod 12-4 is pulled downward, and the pull rod 12-4 drives the pushing block 12-3 to move downward, so that the return spring 12-5 is compressed. At this time, the connecting spring 12-2 drives the mounting block 12-1 to retract into the square block 11, so that the piston plate 8-2 can be removed. After replacing the new piston plate 8-2, the pull rod 12-4 can be loosened, and the pull rod 12-4 moves to the side of the mounting block 12-1 under the elastic force of the return spring 12-5, so that the pushing block 12-3 pushes the mounting block 12-1, so that the mounting block 12-1 is inserted into the connecting rod 8-1 to achieve the limiting effect.

[0029] Compared with the prior art, the beneficial effects of this specific embodiment are as follows: 1. Through the linkage design of the blocking rod 3 and the push rod 7, the melt flow and cutting timing are precisely controlled, effectively preventing material backflow and accumulation at the outlet, and significantly improving the dimensional accuracy and surface quality of the injection molded products; 2. The motor-driven synchronous wheel transmission mechanism, combined with the precise coordination of the guide rod 9 and the movable plate 4, ensures smooth, accurate and quick sealing action, significantly reduces mechanical vibration and component wear, and improves system reliability. 3. The innovative use of the pneumatic transmission system of the movable tube 6 and the ventilation sleeve 8-4 enables the push rod 7 to automatically clean the residual material at the discharge port, completely avoiding the blockage problem caused by the accumulation of cold materials and ensuring the stability of continuous production; 4. The piston plate 8-2 adopts a unique quick-release structure, combined with the design of a detachable sealing cover 14, making daily maintenance and component replacement more convenient and efficient, significantly reducing maintenance costs and extending the overall service life of the mold.

[0030] For those skilled in the art, they can modify the technical solutions described in the aforementioned embodiments and 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 in the scope of protection of the present invention.

Claims

1. A hot runner injection molding structure for injection molds, comprising a feed pipe (1) and a mounting plate (2), wherein heating rings are embedded in the ring wall of the feed pipe (1) at equal intervals, and the mounting plate (2) is sleeved and fixed on the outer side of the feed pipe (1); characterized in that: It also contains: A blocking rod (3), wherein the blocking rod (3) is arranged inside the delivery pipe (1), the lower end of the blocking rod (3) is arranged to cooperate with and abut against the outlet end of the delivery pipe (1), and the upper end of the blocking rod (3) is in the through opening of the upper end of the delivery pipe (1); A movable plate (4), wherein the movable plate (4) is suspended on the upper side of the mounting plate (2), the movable plate (4) is movable and penetrates the through-hole on the conveying pipe (1), the upper end of the blocking rod (3) is inserted into the movable plate (4), and the movable plate (4) is connected to the conveying pipe (1) via a driving mechanism (5); There are two movable tubes (6), which are fixed symmetrically on both sides of the lower surface of the movable plate (4). The movable tubes (6) are inserted into the mounting plate (2), and the lower ends of the movable tubes (6) are located in the cylindrical groove inside the mounting plate (2); A push rod (7), wherein the push rod (7) is movably arranged in the blocking rod (3), and the outer ring wall of the push rod (7) is arranged to cooperate with and abut against the inner wall of the blocking rod (3); The pushing mechanism (8) is two and is symmetrically arranged in the movable plate (4). The pushing mechanism (8) is connected to the blocking rod (3) and the adjacent movable tube (6).

2. The hot runner backflow injection molding structure of an injection mold according to claim 1, characterized in that: The driving mechanism (5) comprises: A driving disk (5-1), wherein the driving disks (5-1) are two and are symmetrically arranged on the two inner walls of the through-opening of the delivery pipe (1), and the protrusions on the driving disks (5-1) are screwed into the delivery pipe (1) via bearings; A drive shaft (5-2), wherein the drive shaft (5-2) is screwed into the upper end of the conveying pipe (1) via a bearing, and both ends of the drive shaft (5-2) are connected to protrusions on both sides of the drive disc (5-1) via synchronous wheel transmission assemblies; A driving motor (5-3), wherein the driving motor (5-3) is embedded in and fixed in the top wall of the conveying pipe (1), and the output shaft of the driving motor (5-3) is connected to the middle end of the driving shaft (5-2) via a bevel gear pair; There are two toggle rods (5-4), which are eccentrically fixed on one side wall of the driving disk (5-1) adjacent to the movable plate (4). The toggle rods (5-4) are movably inserted into the waist-shaped holes on the movable plate (4).

3. The hot runner backflow injection molding structure of an injection mold according to claim 1, characterized in that: The movable plate (4) is located on the lower side wall of one side inside the conveying pipe (1) and is penetrated by a guide rod (9). The upper and lower ends of the guide rod (9) are respectively fixed on the upper and lower inner walls of the through-opening of the conveying pipe (1).

4. The hot runner backflow injection molding structure of an injection mold according to claim 1, characterized in that: The pushing mechanism (8) comprises: A connecting rod (8-1), wherein the connecting rod (8-1) is movably inserted into the movable tube (6), a piston plate (8-2) is fixed to the lower end of the connecting rod (8-1), and an outer ring wall of the piston plate (8-2) is arranged to abut against an inner ring wall of the cylindrical groove; A plurality of limit blocks (8-3) are fixed at equal angles on the outer ring wall of the connecting rod (8-1) located at one end inside the movable tube (6), and the limit blocks (8-3) are slidably arranged in a slide groove on the inner ring wall of the movable tube (6); The ventilation sleeve (8-4) is arranged in an "L" shape, and the ventilation sleeve (8-4) is symmetrically arranged in the delivery pipe (1). After the horizontal pipe of the ventilation sleeve (8-4) passes through the annular wall of the delivery pipe (1), it is inserted into the mounting plate (2), and the ventilation sleeve (8-4) is arranged to be connected with the cylindrical groove. The horizontal pipe of the ventilation sleeve (8-4) has a built-in control valve; The ventilation cannula (8-5) is arranged in an inverted "L" shape, the vertical tube of the ventilation cannula (8-5) is movably inserted into the vertical tube of the ventilation sleeve (8-4), and the horizontal tube of the ventilation cannula (8-5) is inserted through the blocking rod (3).

5. The hot runner backflow injection molding structure of an injection mold according to claim 4, characterized in that: A sealing ring (10) is sleeved on the outer ring wall of the vertical tube of the ventilation cannula (8-5), and the outer ring wall of the sealing ring (10) is matched and abutted against the inner ring wall of the vertical tube of the ventilation cannula (8-4).

6. The hot runner backflow injection molding structure of an injection mold according to claim 4, characterized in that: A square block (11) is fixed on the top wall of the piston plate (8-2), and the square block (11) is inserted into the connecting rod (8-1). A circular groove is provided on the lower surface of the piston plate (8-2), and a mounting mechanism (12) is provided in the circular groove. The mounting mechanism (12) is connected to the connecting rod (8-1).

7. The hot runner backflow injection molding structure of an injection mold according to claim 6, characterized in that: The mounting mechanism (12) comprises: Mounting blocks (12-1), there are two mounting blocks (12-1), which are symmetrically arranged in the square block (11). One side of the mounting block (12-1) passes through the square block (11) and is inserted into the limiting groove on the inner wall of the connecting rod (8-1). A connecting spring (12-2) is fixed on the other side wall of the mounting block (12-1), and the connecting spring (12-2) is fixed on the inner wall of the square block (11); A pushing block (12-3), wherein the pushing block (12-3) is arranged in the square block (11), a pull rod (12-4) is fixed on the lower side wall of the pushing block (12-3), and the lower end of the pull rod (12-4) passes through the piston plate (8-2) and is located in the circular groove; A return spring (12-5) is sleeved on one end of the pull rod (12-4) located inside the square block (11), and two ends of the return spring (12-5) are fixedly connected to the push block (12-3) and the inner wall of the square block (11), respectively.

8. The hot runner backflow injection molding structure of an injection mold according to claim 7, characterized in that: A gripping rod (13) is fixed to the lower end of the pull rod (12-4), and the gripping rod (13) is located in the circular groove.

9. The hot runner backflow injection molding structure of an injection mold according to claim 7, characterized in that: A circular hole is provided on the bottom wall of the mounting plate (2) and is connected to the cylindrical groove. A sealing cover (14) is screwed into the circular hole through a thread. The circular plate on the lower side of the sealing cover (14) is arranged to abut against the lower side wall of the mounting plate (2).

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