Anti-backflow shoe mold injection head assembly

Abstract

The utility model relates to a backflow prevention shoe mould injection head subassembly, including injection head body, injection material mouth, injection nozzle and open and close control mechanism. The first push inclined plane structure is equipped with in injection nozzle end, and the open and close control mechanism contains wedge sliding unit and elastic reset subassembly, when injection nozzle removes, the first push inclined plane structure pushes the wedge sliding unit and opens injection material mouth, and when far away, the elastic reset subassembly drives its reset and closes injection material mouth. This structure realizes the active opening and closing of injection material mouth, and promotes the backflow prevention and the sealing reliability.

Description

Technical Field

[0001] This utility model specifically relates to an anti-backflow shoe mold injection head assembly. Background Technology

[0002] Wall-mounted injection molding technology is one of the core processes in shoe manufacturing molds. It involves injecting shoe materials (such as polyurethane and rubber) into the mold after it closes, effectively improving the molding precision and production efficiency of shoe soles. In existing technologies, the injection head of wall-mounted injection molds typically relies on a passive mechanical structure for opening and closing control. For example, the "Injection Head of a Horizontal Plastic Injection Molding Machine" disclosed in Chinese Invention Patent Publication No. CN101104306B mainly consists of an injection head body, a T-shaped injection nozzle, a material closing nozzle, and irregularly shaped connecting holes. The injection nozzle is passively opened by mold pressure and closes by its own weight and material pressure. The material closing nozzle achieves anti-backflow sealing through a sliding fit within a stepped hole, relying on the material pressure difference. While this structure can meet basic injection functions, it has the following drawbacks in practical applications: the injection nozzle closure relies on the weight of the sealing part (upper T-shape) and the material pressure falling back, lacking independent reset power. When the material has high viscosity (such as rubber shoe materials) or the temperature decreases, causing a reduction in fluidity, the sealing part falls back slowly, which can easily lead to mold closing delay. By this time, the mold has already begun to close, inevitably causing material to overflow in the mold gaps, forming burrs and directly affecting the quality of the shoes. Therefore, the anti-backflow and sealing reliability are poor, and residual material can flow back to the pre-plasticizing mechanism, causing equipment blockage. Utility Model Content

[0003] To address the shortcomings of existing technologies, this invention provides an anti-backflow shoe mold injection head assembly that improves anti-backflow and sealing reliability.

[0004] To achieve the above objectives, the present invention provides the following technical solution: an anti-backflow shoe mold injection head assembly, comprising an injection head body, an injection port on the injection head body, and an injection nozzle for injecting molten plastic into the injection port. The injection head body is equipped with an opening and closing control mechanism for controlling the opening and closing of the injection port. The end of the injection nozzle facing the injection head body is provided with an inclined first pushing slope structure. The opening and closing control mechanism includes a wedge-shaped sliding unit and an elastic reset component connected to the wedge-shaped sliding unit. When the injection nozzle moves towards the injection port, the first pushing slope structure synchronously pushes the wedge-shaped sliding unit to open the injection port. When the injection nozzle moves away from the injection port, the elastic reset component pushes the wedge-shaped sliding unit to reset and close the injection port.

[0005] The beneficial effects of this invention are as follows: By setting a wedge-shaped sliding unit and an elastic reset component, active opening and closing control of the injection port is achieved, avoiding the mold closing delay problem caused by relying on the material's own weight and pressure in the prior art. This effectively prevents overflow and burrs, improving the quality of shoe molding. Specifically, the wedge-shaped sliding unit achieves linear displacement through inclined sliding, ensuring that the injection port responds quickly to opening and closing actions during injection. The elastic reset component provides independent reset power, ensuring rapid closure of the injection port even under conditions of high material viscosity or low temperature, reducing the risk of residual material backflow and thus lowering the probability of equipment blockage. As a preferred embodiment, the wedge-shaped sliding unit can be designed to include a sliding block and a guide component. The sliding block interacts with the injection nozzle through an inclined surface, pushing the sliding block along the guide path to open the injection port when the injection nozzle advances. The elastic reset component uses a compression spring mechanism, driving the sliding block to reset through spring force when the injection nozzle retracts, achieving immediate sealing of the injection port. As another preferred approach, the wedge-shaped sliding unit can integrate a multi-sloping surface structure. Through precise slope angles and sliding guidance, it ensures the smoothness and repeatability of the opening and closing process, thereby enhancing the overall sealing reliability and avoiding operational errors caused by changes in material flowability.

[0006] Furthermore, the wedge-shaped sliding unit includes a first sealing rod and a pushing block with one end connected to the first sealing rod, the other end of the pushing block being linked to the elastic reset component; the injection head body has two sets of first guide holes symmetrically distributed on both sides of the injection port, both sets of first guide holes are connected to the injection port, and a set of first sealing rods can be slidably installed in each set of first guide holes; the end of the first guide hole away from the injection port is connected to a sliding guide groove opened on the injection head body, and the pushing block can be slidably installed in the sliding guide groove; the side of the pushing block facing the injection nozzle has a second pushing inclined surface structure parallel to the first pushing inclined surface structure.

[0007] This structure, through symmetrically arranged first guide holes and sliding guide grooves, ensures the stability and precision of the wedge-shaped sliding unit's movement, thereby improving the consistency of the injection port's opening and closing and reducing the risk of seal failure due to uneven force on one side. The connection design between the first sealing rod and the push block makes the opening and closing control more reliable. The second push inclined surface structure is parallel to the first push inclined surface structure, further optimizing the thrust transmission efficiency and avoiding energy loss. As a preferred option, the push block can be made of high-strength material, and its second push inclined surface structure is precision-machined to form a sliding fit with the first push inclined surface structure of the injection nozzle. When the injection nozzle moves, the inclined surfaces interact to drive the push block to slide linearly along the sliding guide groove, thereby driving the first sealing rod to move within the first guide hole, realizing the rapid opening or closing of the injection port. This structure ensures that it can maintain rapid action to control the opening and closing of the injection port even in high-viscosity material environments. As another preferred approach, the first guide hole can be designed as a guide channel with a wear-resistant bushing to extend service life and reduce frictional resistance, thereby ensuring that the first sealing rod can still be accurately reset in multiple cycles, improving the overall durability and backflow prevention effect of the component.

[0008] Furthermore, the elastic reset assembly includes a spring, and the end of the sliding guide groove away from the injection port is connected to a first mounting hole opened on the injection head body. The spring is inserted into the first mounting hole, and one end of the spring presses against the inner end of the first mounting hole.

[0009] The spring design provides a stable reset force source for the elastic reset assembly, ensuring that the wedge-shaped sliding unit can be quickly reset when the injection nozzle retracts, thereby effectively closing the injection port and preventing material backflow and overflow. The spring is placed within the first mounting hole, featuring a compact structure for easy installation and maintenance. Its press-fit fixing method enhances the overall rigidity and reliability of the assembly. As a preferred option, a helical compression spring can be used, installed within the first mounting hole and preloaded via end press-fit. When the injection nozzle moves away from the injection port, the spring releases its stored elastic potential energy, driving the push block and the first sealing rod to quickly reset, ensuring the injection port is completely closed before mold closing and preventing material leakage due to delay. Alternatively, the first mounting hole can be designed as a stepped structure to accommodate springs of different sizes and provide a stable support point through the inner end face, thereby optimizing the force distribution of the spring, improving the response speed and consistency of the reset action, and further enhancing the anti-backflow performance.

[0010] Furthermore, the elastic reset assembly also includes a guide shaft, the end of which facing the push block is fixedly connected to a flange ring with an outer diameter larger than the guide shaft, the spring is sleeved on the outer circumference of the guide shaft, and the other end of the spring presses against the flange ring; the end of the first mounting hole away from the sliding guide groove is connected to a sliding extension hole opened on the injection head body, and the end of the guide shaft away from the flange ring is inserted into the sliding extension hole.

[0011] The design of the guide shaft and flange ring ensures more even guidance and force distribution of the spring, preventing spring misalignment or jamming during compression and release, thus improving the accuracy and durability of the reset action. The sliding extension hole provides more movement space for the guide shaft, ensuring stable operation of the entire elastic reset assembly through multiple cycles. As a preferred embodiment, the guide shaft can be made of hard alloy material, with its flange ring connected to the guide shaft by welding or integral molding. The spring is sleeved on the outer circumference of the guide shaft and supported by the flange ring. When the injection nozzle retracts, the spring linearly compresses or extends under the guidance of the guide shaft, driving the push block to reset. This structure reduces component wear and extends assembly life. Alternatively, the sliding extension hole can be designed as a channel with lubrication grooves to reduce frictional resistance during guide shaft movement, ensuring smooth and unobstructed reset, further improving the timeliness and sealing reliability of the injection port closure.

[0012] Furthermore, the elastic reset assembly also includes a second sealing rod connected to the guide shaft. The push block has a second mounting hole, and the first sealing rod has a third mounting hole coaxial with the second mounting hole. The second sealing rod is inserted into the second mounting hole and the third mounting hole in sequence. A sealing ring distributed in the third mounting hole is sleeved on the outer periphery of the second sealing rod. When the injection nozzle moves away from the injection port, the spring will push the push block and the second sealing rod to reset. The ends of the two sets of second sealing rods abut against each other to block the injection port.

[0013] The inclusion of a second sealing rod and a sealing ring enhances the dual sealing mechanism of the injection port. By abutting each other at their ends, it effectively prevents material leakage under high pressure and improves backflow prevention. The coaxial design of the second and third mounting holes ensures the alignment of the second sealing rod's movement, reducing the risk of seal failure due to misalignment. During reset, the second sealing rod moves forward under spring drive until the ends of the two sets of second sealing rods abut each other, forming a mechanical seal. Simultaneously, the sealing ring provides auxiliary sealing to prevent minor leaks. As a preferred option, the second and third mounting holes can be designed as channels with guide surfaces to ensure that the second sealing rod remains vertically aligned throughout its movement, thereby optimizing the uniformity of the sealing contact surface and further improving sealing reliability in high-temperature or high-viscosity material environments.

[0014] Furthermore, the end of the first sealing rod away from the push block is provided with an arc-shaped notch, and the two sets of arc-shaped notches form a circular opening, the inner diameter of which is smaller than the outer diameter of the second sealing rod.

[0015] The arc-shaped notch design allows the two sets of first sealing rods to form a complete circular opening when closed. The circular opening optimizes the flow channel shape of the injection port and reduces material flow resistance. During the process of the second sealing rod sealing the injection port, the arc-shaped notch of the first sealing rod contacts the material first to provide buffering and prevent the second sealing rod from experiencing greater resistance.

[0016] Furthermore, the first pushing inclined surface structure is a truncated cone, and the second pushing inclined surface structure is a conical surface parallel to the truncated cone.

[0017] The parallel design of the truncated cone and the conical surface ensures efficient energy transfer between the first and second pushing inclined surfaces during interaction, reducing energy loss and friction, thereby improving the response speed and accuracy of opening and closing control. This geometry optimizes the contact area of ​​the inclined surfaces, enhancing durability. As a preferred option, the first pushing inclined surface can be machined into a high-precision truncated cone with a taper consistent with the conical surface of the second pushing inclined surface. During nozzle movement, the conical surface interaction generates uniform thrust, driving the wedge-shaped sliding unit to move smoothly, achieving rapid opening of the injection port while reducing impact and wear between components. Alternatively, the conical surface can undergo surface hardening treatment to enhance wear resistance and, through a tight fit with the truncated cone, ensure accurate inclined surface interaction even after multiple cycles, thus maintaining long-term backflow prevention and sealing performance.

[0018] Furthermore, the injection head body includes a main mounting frame and two sets of auxiliary mounting blocks that are detachably connected to the main mounting frame by screws. The main mounting frame has a protrusion at the center of one end facing the injection nozzle. The two sets of auxiliary mounting blocks are symmetrically distributed on both sides of the protrusion. The injection port and the two sets of first guide holes are all opened on the protrusion. The sliding guide groove, the first mounting hole, and the sliding extension hole are all opened on the auxiliary mounting blocks.

[0019] This modular design facilitates component assembly, maintenance, and replacement through the detachable connection of the main mounting bracket and sub-mounting blocks. The symmetrically distributed sub-mounting blocks and protrusions ensure structural balance and uniform stress distribution, enhancing overall stability.

[0020] The beneficial effects of this invention are as follows: By setting a wedge-shaped sliding unit and an elastic reset component, the passive closing method relying on the material's own weight and pressure in the prior art is replaced, realizing active opening and closing control of the injection port. When the injection nozzle moves, the inclined structure pushes the wedge-shaped sliding unit to open the injection port. After the injection is completed, the elastic reset component quickly drives it to close, effectively solving the problem of mold closing delay caused by high viscosity or low temperature materials, avoiding overflow and forming burrs, and improving the shoe molding quality. At the same time, the independent reset power reduces the risk of residual material flowing back to the pre-plasticizing mechanism, reduces the probability of equipment blockage, and enhances the reliability of backflow prevention and sealing.

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present utility model; Figure 2 This is an exploded view of an embodiment of the present invention; Figure 3 This is a top-view perspective diagram of an embodiment of the present invention; Figure 4 for Figure 3 Schematic diagram of the cross section along line A-A; Figure 5 This is a schematic diagram of the elastic reset component according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the wedge-shaped sliding unit according to an embodiment of the present invention.

[0023] Labeling notes: Injection head body 1, Injection port 11, First guide hole 12, Sliding guide groove 13, First mounting hole 14, Sliding extension hole 15, Main mounting bracket 16, Secondary mounting block 17; Injection nozzle 2, First pushing inclined surface structure 21; First sealing rod 311, Third mounting hole 3111, Sealing ring 3112, Arc-shaped notch 3113; Push block 312, Second pushing inclined surface structure 3121, Second mounting hole 3122; Spring 321; Guide shaft 322, Flange ring 3221; Second sealing rod 323. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0025] like Figures 1 to 6The anti-backflow shoe mold injection head assembly shown includes an injection head body 1, an injection port 11 opened on the injection head body 1, and an injection nozzle 2 for injecting molten plastic into the injection port 11. An opening and closing control mechanism for controlling the opening and closing of the injection port 11 is installed on the injection head body 1. The end of the injection nozzle 2 facing the injection head body 1 is provided with an inclined first pushing slope structure 21. The opening and closing control mechanism includes a wedge-shaped sliding unit and an elastic reset component connected to the wedge-shaped sliding unit. When the injection nozzle 2 moves toward the injection port 11, the first pushing slope structure 21 will simultaneously push the wedge-shaped sliding unit to open the injection port 11. When the injection nozzle 2 moves away from the injection port 11, the elastic reset component will push the wedge-shaped sliding unit to reset to close the injection port 11. The injection head body 1 serves as the basic support structure, ensuring the overall stability and precision of the assembly; the injection port 11 guides the molten plastic into the mold, improving injection efficiency; the injection nozzle 2 serves as the injection component, realizing the delivery of plastic; the first pushing inclined surface structure 21 transforms the linear motion of the injection nozzle 2 into the sliding of the wedge-shaped sliding unit through the inclined surface design, realizing automatic opening and closing control; the opening and closing control mechanism integrates mechanical and elastic elements, improving response speed and reliability; the wedge-shaped sliding unit utilizes inclined surface sliding to achieve precise displacement; the elastic reset component provides reset force, ensuring that the injection port 11 closes in time, preventing plastic backflow.

[0026] The wedge-shaped sliding unit includes a first sealing rod 311 and a push block 312 connected at one end to the first sealing rod 311. The other end of the push block 312 is linked to the elastic reset component. The injection head body 1 has two sets of first guide holes 12 symmetrically distributed on both sides of the injection port 11. Both sets of first guide holes 12 are connected to the injection port 11. A set of first sealing rods 311 can be slidably installed in each set of first guide holes 12. The end of the first guide hole 12 away from the injection port 11 is connected to a sliding guide groove 13 opened on the injection head body 1. The push block 312 can be slidably installed in the sliding guide groove 13. The side of the push block 312 facing the injection nozzle 2 has a second push inclined surface structure 3121 parallel to the first push inclined surface structure 21. The first sealing rod 311 directly controls the opening and closing of the injection port 11 by sliding, improving the sealing performance; the push block 312 acts as a transmission component, transmitting the inclined plane thrust to the first sealing rod 311; the first guide hole 12 guides the sliding trajectory of the first sealing rod 311, reducing friction and wear; the sliding guide groove 13 provides a stable sliding path for the push block 312, enhancing the overall rigidity; the second pushing inclined plane structure 3121 cooperates with the first pushing inclined plane structure 21 to achieve efficient force transmission and motion conversion.

[0027] The elastic reset assembly includes a spring 321. The end of the sliding guide groove 13 away from the injection port 11 is connected to a first mounting hole 14 formed on the injection head body 1. The spring 321 is inserted into the first mounting hole 14, and one end of the spring 321 presses against the inner end of the first mounting hole 14. The spring 321 provides elastic force to drive the wedge-shaped sliding unit to reset, ensuring that the injection port 11 closes quickly. The first mounting hole 14 fixes the position of the spring 321 to prevent displacement and improve reset accuracy.

[0028] The elastic reset assembly also includes a guide shaft 322. A flange ring 3221 with an outer diameter larger than the guide shaft 322 is fixedly connected to the end of the guide shaft 322 facing the push block 312. A spring 321 is sleeved on the outer circumference of the guide shaft 322, and the other end of the spring 321 presses against the flange ring 3221. The end of the first mounting hole 14 away from the sliding guide groove 13 communicates with a sliding extension hole 15 opened on the injection head body 1. The end of the guide shaft 322 away from the flange ring 3221 is inserted into the sliding extension hole 15. The guide shaft 322 guides the compression and extension of the spring 321, preventing bending deformation; the flange ring 3221 serves as a support point for the spring 321, evenly distributing pressure; the sliding extension hole 15 provides additional sliding space for the guide shaft 322, enhancing motion stability.

[0029] The elastic reset assembly also includes a second sealing rod 323 connected to the guide shaft 322. A second mounting hole 3122 is provided in the push block 312. A third mounting hole 3111 is provided in the first sealing rod 311, which is coaxial with the second mounting hole 3122. The second sealing rod 323 is inserted into the second mounting hole 3122 and the third mounting hole 3111 in sequence. A sealing ring 3112 distributed in the third mounting hole 3111 is sleeved on the outer periphery of the second sealing rod 323. When the injection nozzle 2 moves away from the injection port 11, the spring 321 will push the push block 312 and the second sealing rod 323 to reset. The ends of the two sets of second sealing rods 323 abut against each other to block the injection port 11. The second sealing rod 323 serves as an auxiliary sealing component, enhancing the closing effect of the injection port 11; the second mounting hole 3122 and the third mounting hole 3111 ensure the alignment and sliding of the second sealing rod 323; the sealing ring 3112 improves the sealing performance and prevents plastic leakage; the ends of the two sets of second sealing rods 323 abut against each other to form a double seal, improving the reliability of backflow prevention.

[0030] The first sealing rod 311 has an arc-shaped notch 3113 at its end away from the push block 312. Two sets of arc-shaped notches 3113 form a circular opening, the inner diameter of which is smaller than the outer diameter of the second sealing rod 323. The arc-shaped notch 3113 design allows the first sealing rod 311 to form a smooth channel when opened, reducing plastic residue; the circular opening matches the dimensions of the second sealing rod 323 to ensure a tight seal when closed.

[0031] The first pushing inclined surface structure 21 is a truncated cone, and the second pushing inclined surface structure 3121 is a conical surface parallel to the truncated cone. The design of the truncated cone and the conical surface optimizes force transmission efficiency, reduces energy loss, and improves motion smoothness.

[0032] The injection head body 1 includes a main mounting bracket 16 and two sets of auxiliary mounting blocks 17, each detachably connected to the main mounting bracket 16 via screws. A protrusion is located at the center of the end of the main mounting bracket 16 facing the injection nozzle 2. The two sets of auxiliary mounting blocks 17 are symmetrically distributed on both sides of the protrusion. The injection port 11 and two sets of first guide holes 12 are all located on the protrusion. A sliding guide groove 13, a first mounting hole 14, and a sliding extension hole 15 are all located on the auxiliary mounting blocks 17. The main mounting bracket 16 and the auxiliary mounting blocks 17 are connected by screws for easy disassembly and maintenance; the protrusion concentrates key structures, improving space utilization; the auxiliary mounting blocks 17 distribute sliding and mounting holes, enhancing modular design.

[0033] The working principle of this utility model embodiment is as follows: During the injection molding process, the injection nozzle 2 moves towards the injection port 11. The first pushing inclined surface structure 21 contacts the second pushing inclined surface structure 3121 and pushes the pushing block 312 to slide along the sliding guide groove 13, causing the first sealing rod 311 to move within the first guide hole 12. The second sealing rod 323 moves synchronously with the first sealing rod 311, thereby opening the injection port 11, and the molten plastic is injected into the mold through the injection port 11. When the injection is completed, the injection nozzle 2 moves away from the injection port 11. The spring 321 of the elastic reset component pushes the pushing block 312 to reset through the guide shaft 322 and the flange ring 3221, thereby causing the first sealing rod 311 and the second sealing rod 323 to close the injection port 11. The ends of the second sealing rod 323 abut against each other and use the sealing ring 3112 to enhance the seal and prevent plastic backflow. Throughout the process, the inclined surface structure and the elastic element work together to achieve automatic and efficient opening and closing control.

[0034] The above embodiments are merely one preferred embodiment of the present utility model. Ordinary changes and substitutions made by those skilled in the art within the scope of the present utility model's technical solution are all included within the protection scope of the present utility model.

Claims

1. An anti-backflow shoe mold injection head assembly, comprising an injection head body, an injection port formed on the injection head body, and an injection nozzle for injecting molten plastic into the injection port, wherein the injection head body is equipped with an opening and closing control mechanism for controlling the opening or closing of the injection port, characterized in that: The end of the injection nozzle facing the injection head body is provided with an inclined first pushing slope structure. The opening and closing control mechanism includes a wedge-shaped sliding unit and an elastic reset component connected to the wedge-shaped sliding unit. When the injection nozzle moves toward the injection port, the first pushing slope structure will simultaneously push the wedge-shaped sliding unit to open the injection port. When the injection nozzle moves away from the injection port, the elastic reset component will push the wedge-shaped sliding unit to reset to close the injection port.

2. The anti-backflow shoe mold injection head assembly according to claim 1, characterized in that: The wedge-shaped sliding unit includes a first sealing rod and a pushing block with one end connected to the first sealing rod. The other end of the pushing block is linked to the elastic reset component. The injection head body has two sets of first guide holes symmetrically distributed on both sides of the injection port. Both sets of first guide holes are connected to the injection port. A set of first sealing rods can be slidably installed in each set of first guide holes. The end of the first guide hole away from the injection port is connected to a sliding guide groove opened on the injection head body. The pushing block can be slidably installed in the sliding guide groove. The side of the pushing block facing the injection nozzle has a second pushing inclined surface structure parallel to the first pushing inclined surface structure.

3. The anti-backflow shoe mold injection head assembly according to claim 2, characterized in that: The elastic reset assembly includes a spring. The end of the sliding guide groove away from the injection port is connected to a first mounting hole opened on the injection head body. The spring is inserted into the first mounting hole, and one end of the spring presses against the inner end of the first mounting hole.

4. The anti-backflow shoe mold injection head assembly according to claim 3, characterized in that: The elastic reset assembly also includes a guide shaft, the end of which facing the push block is fixedly connected to a flange ring with an outer diameter larger than the guide shaft, the spring is sleeved on the outer circumference of the guide shaft, and the other end of the spring presses against the flange ring; the end of the first mounting hole away from the sliding guide groove is connected to a sliding extension hole opened on the injection head body, and the end of the guide shaft away from the flange ring is inserted into the sliding extension hole.

5. The anti-backflow shoe mold injection head assembly according to claim 4, characterized in that: The elastic reset assembly also includes a second sealing rod connected to the guide shaft. The push block has a second mounting hole, and the first sealing rod has a third mounting hole coaxial with the second mounting hole. The second sealing rod is inserted into the second mounting hole and the third mounting hole in sequence. The outer periphery of the second sealing rod is fitted with sealing rings distributed in the third mounting hole. When the injection nozzle moves away from the injection port, the spring will push the push block and the second sealing rod to reset. The ends of the two sets of second sealing rods abut against each other to block the injection port.

6. The anti-backflow shoe mold injection head assembly according to claim 5, characterized in that: The first sealing rod has an arc-shaped notch at its end away from the push block, and the two sets of arc-shaped notches form a circular opening, the inner diameter of which is smaller than the outer diameter of the second sealing rod.

7. The anti-backflow shoe mold injection head assembly according to any one of claims 2 to 6, characterized in that: The first pushing inclined surface structure is a truncated cone, and the second pushing inclined surface structure is a conical surface parallel to the truncated cone.

8. The anti-backflow shoe mold injection head assembly according to claim 4, 5, or 6, characterized in that: The injection head body includes a main mounting frame and two sets of auxiliary mounting blocks that are detachably connected to the main mounting frame by screws. The main mounting frame has a protrusion in the middle of one end facing the injection nozzle. The two sets of auxiliary mounting blocks are symmetrically distributed on both sides of the protrusion. The injection port and the two sets of first guide holes are all opened on the protrusion. The sliding guide groove, the first mounting hole, and the sliding extension hole are all opened on the auxiliary mounting blocks.

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