A hot runner annular hot nozzle structure

Abstract

The utility model relates to a hot runner annular hot nozzle structure, including valve needle, shunt plate and hot nozzle, one side of shunt plate is equipped with the glue inlet, the glue inlet is connected with the internal flow channel of shunt plate, the other side of shunt plate is equipped with the guide hole of the penetration shunt plate, the guide hole is aligned with the glue inlet center, the radial dimension of guide hole is less than the radial dimension of glue inlet, valve needle is installed in the guide hole, hot nozzle is installed on the glue inlet, the center of hot nozzle is formed end flow channel through, valve needle penetrates end flow channel and goes out hot nozzle, its characterized in that: one end of hot nozzle away from shunt plate is equipped with the discharge gate, and the end of valve needle is equipped with the glue sealing part, and the glue sealing part is equipped with the glue outlet along the opposite direction of valve needle, the radial dimension of glue outlet is less than the radial dimension of glue sealing part, and the radial dimension of glue sealing part is same with the radial dimension of discharge gate. Adopt the valve needle structure of special make-up, can realize the function of annular glue inlet, to improve the glue inlet efficiency, can also quickly disassemble, and the later disassembly maintenance is convenient.

Description

Technical Field

[0001] This utility model relates to the field of hot runner technology, and in particular to a hot runner annular hot nozzle structure. Background Technology

[0002] Hot runner technology, as a significant innovation in injection molding, has been widely applied in industries such as automotive, electronics, and medical due to its advantages of high efficiency, energy saving, and reduced waste. Traditional hot runner systems mostly employ point gates, needle valve gates, or submarine gates, achieving uniform melt distribution and efficient molding through precise temperature control and runner design. However, existing hot runner systems still suffer from problems such as uneven melt flow, poor venting, and gate residue affecting the appearance when dealing with multi-cavity molds or products requiring high symmetry.

[0003] Annular gates, as a special type of gate, are characterized by the uniform circumferential entry of the melt into the mold cavity, effectively reducing weld lines, lowering internal stress, and optimizing venting. This technology is often combined with cold runner systems and is suitable for molding thin-walled long tubular or symmetrical products. However, while the slurry recovery mechanism of cold runners can reduce material waste, the large cross-sectional area of ​​annular gates makes gate removal difficult and leaves noticeable marks on the product surface. Furthermore, the temperature control of cold runner systems relies on external cooling media, making it difficult to achieve a precise balance between melt flowability and product quality.

[0004] While hot runner systems offer significant advantages in zero-waste production and rapid filling, their combination with annular gates has not been fully explored. Existing research indicates that synergistic optimization of the high-temperature melt of hot runners and the uniform feeding characteristics of annular gates could further improve product quality and expand application range. For example, in high-precision fields such as medical and automotive, zero-waste production using hot runners can reduce the waste of expensive materials, while the uniform filling capability of annular gates can reduce weld lines and deformation risks. However, combining the two still faces key technical challenges: firstly, the large cross-sectional area of ​​annular gates increases the difficulty of removing gate residues; secondly, the complex structural design must balance runner sealing and maintenance convenience. Therefore, an innovative solution that combines the high efficiency of hot runners with the uniformity of annular gates is urgently needed to resolve these technical contradictions and promote the further development of injection molding processes.

[0005] Patent No. 202311705167.3 discloses an annular glue inlet and glue cutting device and its control system. The valve needle is shaped like a car engine valve. It uses an annular skirt to control the glue inlet amount of the annular gate and can cut off the glue inlet in time, effectively reducing the residue at the gate and improving the utilization rate of the glue. However, when the valve needle end size is larger than the gate size, it is not conducive to the later disassembly and maintenance, adding unnecessary costs for customers. Utility Model Content

[0006] In view of the shortcomings of the existing technology, the technical problem to be solved by this utility model is to provide a hot runner annular hot nozzle structure, which adopts a specially designed valve needle structure, so as to realize the function of annular glue injection to improve glue injection efficiency, and can be quickly disassembled and assembled, which is convenient for later disassembly and maintenance.

[0007] To solve the above technical problems, a hot runner annular hot nozzle structure is provided, including a valve needle, a manifold, and a hot nozzle. One side of the manifold has an inlet connected to the internal flow channel of the manifold. The other side of the manifold has a guide hole that penetrates the manifold and is aligned with the center of the inlet. The radial dimension of the guide hole is smaller than that of the inlet. The valve needle is installed in the guide hole, and the hot nozzle is installed on the inlet. The center of the hot nozzle forms an end flow channel. The valve needle passes through the end flow channel and exits the hot nozzle. The end of the hot nozzle away from the manifold has an outlet. The end of the valve needle has a sealing part, and the sealing part has an outlet part in the opposite direction of the valve needle. The radial dimension of the outlet part is smaller than that of the sealing part, and the radial dimension of the sealing part is the same as that of the outlet part.

[0008] In general hot runner valve needle systems, the design typically uses a point-jet pattern where the nozzle is blocked by a pointed tip. However, when producing hollow cylindrical products, a mold core directly faces the nozzle within the cavity. In this case, the molten material from the point-jet pattern directly impacts the mold core, resulting in low injection efficiency and noticeable weld lines. The annular injection process, unlike point-jet injection, involves the molten material being ejected from the nozzle outwards. This effectively and quickly fills the cavity, reducing weld lines. With this structure, as the valve needle descends, the sealing section disengages from the nozzle, and the molten material is ejected from the gap between the nozzle and the sealing section—the nozzle itself—achieving an annular injection function. More importantly, the valve needle's dimensions are the same as the nozzle, allowing it to be directly removed from the hot runner nozzle during disassembly and maintenance, reducing disassembly difficulty and improving maintenance efficiency.

[0009] Preferably, the dispensing section includes a tapered flow channel, the radial dimension of which gradually decreases from the top to the sealing section. This tapered flow channel provides a larger dispensing area, improving dispensing efficiency.

[0010] Furthermore, the ejector section includes at least four notched runners, with the bottom of each notched runner serving as a sealing section. Compared to tapered runners, the notched runner design fundamentally controls the amount of material injected. When injection molding thin-walled products, it better controls the total amount of molten material entering, preventing product quality issues such as overflow and flash, and is more adaptable to different products.

[0011] Preferably, the sealing part is detachably mounted on the end of the valve needle. The sealing part can be retracted into the end of the valve needle with a screw. This design firstly facilitates the processing of the dispensing part, and secondly, the sealing part needs to withstand the erosion of molten material during use, resulting in a high wear rate. The detachable design allows the worn sealing part to be replaced without disassembling the upper mold, while also reducing the frequency of replacing the entire valve needle, thereby reducing the difficulty of disassembly and maintenance.

[0012] Specifically, the sealing part is made of P20. Compared with alloy steel, P20 mold steel has strong wear resistance, reducing the probability of wear on the sealing part and increasing its service life.

[0013] Preferably, a sealing gasket is also included. The sealing gasket is fixed to the outlet and has a sealing opening at its center. The stop valve needle passes through the sealing opening, and the radial dimension of the sealing opening is the same as the radial dimension of the sealing part. The manufacturing process of the hot runner needs to prioritize assembly dimensions. If the outlet cannot be precisely machined, there is a risk of glue leakage if used directly. As a component specifically designed to mate with the sealing part, the sealing gasket allows for more precise control of the mating dimensions at the sealing opening, reducing the risk of glue leakage and improving the reliability of the valve needle system.

[0014] Preferably, the hot runner includes a heating cylinder and a dispensing nozzle, with the dispensing port located on the nozzle. The dispensing nozzle is detachably mounted on the heating cylinder, which is mounted on a distributor plate. This split design makes the dispensing nozzle easier to manufacture and reduces the processing difficulty of the hot runner.

[0015] Preferably, the sealing gasket material is silicon nitride ceramic. Since the impact force of the dispensing is entirely applied to the sealing part and the sealing opening, the sealing part and the sealing gasket are extremely prone to wear. Using silicon carbide ceramic for the sealing gasket offers several advantages. First, it has stronger wear resistance compared to alloy steel. Second, during operation, the sealing gasket needs to be at a similar temperature to the nozzle. If the sealing gasket temperature is too low, the molten material will cool and create weld lines on the product, or even stick to the sealing gasket, clogging the nozzle. Silicon carbide ceramic has high thermal conductivity, significantly reducing the probability of these problems occurring.

[0016] Preferably, the system also includes a leak-proof adhesive and a pressure block. The distributor plate has an air vent on the back of the inlet. The leak-proof adhesive is installed in the air vent, with its height exceeding the height of the air vent. The pressure block presses the leak-proof adhesive firmly into the air vent and fixes it to the distributor plate. The valve needle passes through the pressure block and the leak-proof adhesive. Since the molten material has a low viscosity, significant pressure is generated during the injection process. Molten material will inevitably seep into any gaps. The guide hole, as the guide part of the valve needle, will be affected by residual adhesive if it remains inside, impacting the valve needle's movement and consequently affecting product quality, potentially even causing it to spray out of the guide hole. By installing the leak-proof adhesive in the air vent and then pressing it firmly with the pressure block, the leak-proof adhesive adheres tightly to the valve needle, sealing the guide hole and effectively preventing leakage.

[0017] Preferably, an actuator is also included, with the end of the valve needle furthest from the hot nozzle installed in the actuator. The actuator controls the upward and downward movement of the valve needle. The actuator is a cylinder; the cylinder moves downward to open the discharge port and moves upward to close the discharge port. This design is simple, highly reliable, and improves the operating efficiency of the valve needle.

[0018] In summary, the use of a more specialized valve needle structure not only enables the ring-shaped glue injection function to improve glue injection efficiency, but also allows for quick disassembly and assembly, facilitating subsequent disassembly and maintenance. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the assembly structure of this implementation scheme;

[0020] Figure 2 This is a front sectional view of the implementation method of this solution;

[0021] Figure 3 This is the implementation method of this solution. Figure 2 Enlarged structural diagram of number A;

[0022] Figure 4 This is the implementation method of this solution. Figure 2 Enlarged structural diagram of number B;

[0023] Figure 5 This is a schematic diagram of the assembly structure of the hot nozzle and sealing gasket in this embodiment of the solution;

[0024] Figure 6 This is a schematic diagram of the valve needle conical flow channel structure in Embodiment 1 of this solution;

[0025] Figure 7 This is a schematic diagram of the valve needle notch flow channel structure in Embodiment 2 of this solution;

[0026] Figure 8 This is a schematic diagram of the detachable sealing part structure in Embodiment 3 of this solution;

[0027] Among them, valve needle-1, sealing part-11, dispensing part-12, conical flow channel-13, notched flow channel-14, screw-15, flow divider plate-2, inlet-21, guide hole-22, air stop-port-23, hot nozzle-3, end flow channel-31, discharge port-32, heating cylinder-33, dispensing nozzle-34, sealing gasket-4, sealing port-41, leak-proof adhesive-5, pressure block-6. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments.

[0029] A hot runner annular nozzle structure includes a valve needle 1, a flow divider plate 2, and a hot nozzle 3. One side of the flow divider plate 2 is provided with an inlet 21, which is connected to the internal flow channel of the flow divider plate 2. The other side of the flow divider plate 2 is provided with a guide hole 22 penetrating through the flow divider plate 2. The guide hole 22 is aligned with the center of the inlet 21, and the radial dimension of the guide hole 22 is smaller than the radial dimension of the inlet 21. The valve needle 1 is installed in the guide hole 22, and the hot nozzle 3 is installed on the inlet 21. The center of the hot nozzle 3 is through to form an end flow channel 31. The valve needle 1 passes through the end flow channel 31 and exits through the hot nozzle 3. The end of the hot nozzle 3 away from the flow divider plate 2 is provided with a discharge port 32. The end of the valve needle 1 is provided with a sealing part 11. The sealing part 11 is provided with a discharge part 12 in the opposite direction of the valve needle 1. The radial dimension of the discharge part 12 is smaller than that of the sealing part 11, and the radial dimension of the sealing part 11 is the same as that of the discharge port 32.

[0030] In general hot runner valve needle systems, point-jet designs are often used, primarily employing a pointed tip to block the outlet. However, when producing hollow cylindrical products, a mold core directly faces the outlet in the cavity. In this case, the molten material from the point-jet injection directly impacts the mold core, resulting in low injection efficiency and noticeable weld lines. The annular injection process, unlike point-jet injection, involves molten material being injected from the outlet outwards, effectively and quickly filling the cavity and reducing weld lines. With this structure, when the valve needle 1 sinks, the sealing part 11 disengages from the outlet 32, and the molten material is ejected from the gap between the outlet 32 ​​and the sealing part 11—this gap being the outlet 12—achieving the annular injection function. More importantly, the valve needle 1 is the same size as the outlet 32, allowing it to be directly pulled out from the hot nozzle 3 during disassembly and maintenance, reducing disassembly difficulty and improving maintenance efficiency.

[0031] As an example of the first embodiment, please refer to the appendix. Figure 6 The dispensing section 12 includes a tapered flow channel 13, the radial dimension of which gradually decreases from the top to the sealing section 11. This tapered flow channel 13 has a large dispensing area, improving dispensing efficiency.

[0032] As an example two, please refer to the appendix. Figure 7 The ejector section 12 includes at least four notched runners 14, with a sealing section 11 at the bottom of each notched runner 14. Compared to the tapered runner 13, the notched runner 14 design fundamentally controls the amount of molten material injected. When injection molding thin-walled products, it can better control the total amount of molten material entering, preventing product quality problems such as overflow and flash, and is more adaptable to different products.

[0033] As an example three, refer to the appendix. Figure 8The sealing part 11 is detachably installed at the end of the valve needle 1. The sealing part 11 can be retracted into the end of the valve needle 1 with screws 15. This design firstly facilitates the processing of the dispensing part 12. Secondly, the sealing part 11 needs to withstand the erosion of molten material during use, resulting in a high wear rate. The detachable design allows the worn sealing part 11 to be replaced without disassembling the upper mold, while reducing the frequency of replacing the entire valve needle 1, thereby reducing the difficulty of disassembly and maintenance.

[0034] Specifically, the sealing part 11 is made of P20. Compared with alloy steel, P20 mold steel has strong wear resistance, which reduces the probability of wear on the sealing part 11 and increases its service life.

[0035] Preferably, a sealing gasket 4 is also included. The sealing gasket 4 is fixed on the outlet 32, and a sealing port 41 is provided at the center of the sealing gasket 4. The stop valve needle 1 passes through the sealing port 41, and the radial dimension of the sealing port 41 is the same as the radial dimension of the sealing part 11. The manufacturing process of the hot nozzle 3 needs to prioritize the assembly dimensions. If the outlet 32 ​​cannot be machined precisely, there is a risk of glue leakage if used directly. As a component specifically designed to cooperate with the sealing part 11, the sealing gasket 4 allows for more precise control of the fitting dimensions at the sealing port 41, reducing the risk of glue leakage and improving the reliability of the valve needle 1 system.

[0036] Preferably, the hot nozzle 3 includes a heating cylinder 33 and a dispensing nozzle 34, with the dispensing port located on the dispensing nozzle 34. The dispensing nozzle 34 is detachably mounted on the heating cylinder 33, which is mounted on the distributor plate 2. This split design makes the dispensing nozzle 34 easier to process, reducing the processing difficulty of the hot nozzle 3.

[0037] Preferably, the sealing gasket 4 is made of silicon nitride ceramic. Since the impact force of the dispensing is entirely applied to the sealing part 11 and the sealing port 41, the sealing part 11 and the sealing gasket 4 are easily worn. The sealing gasket 4 is made of silicon carbide ceramic, which firstly has stronger wear resistance than alloy steel, and secondly, during operation, the sealing gasket 4 needs to be at a similar temperature to the hot nozzle 3. If the temperature of the sealing gasket 4 is too low, the molten material will be cooled and weld lines will be generated on the product, or even stick to the sealing gasket 4, blocking the nozzle. Silicon carbide ceramic has high thermal conductivity, which greatly reduces the probability of the above problems occurring.

[0038] Preferably, the system also includes a leak-proof adhesive 5 and a pressure block 6. The flow divider 2 has an air-stop port 23 on the back of the glue inlet 21. The leak-proof adhesive 5 is installed in the air-stop port 23, and the height of the leak-proof adhesive 5 is higher than the height of the air-stop port 23. The pressure block 6 presses the leak-proof adhesive 5 tightly in the air-stop port 23 and fixes it on the flow divider 2. The valve needle 1 passes through the pressure block 6 and the leak-proof adhesive 5. The viscosity of the molten material is low, and a large pressure will be generated during the glue injection process. Molten material will seep into any gaps. The guide hole 22 serves as the guide part of the valve needle 1. Residual glue inside the guide hole 22 will affect the movement of the valve needle 1, thereby affecting the quality of the product, and may even spray out from the guide hole 22. By using the leak-proof adhesive 5 installed in the air-stop port 23 and then pressed by the pressure block 6, the leak-proof adhesive 5 is tightly attached to the valve needle 1, sealing the guide hole 22 and effectively preventing glue leakage 5.

[0039] Preferably, an actuator is also included. The end of the valve needle 1 furthest from the hot nozzle 3 is installed in the actuator, which controls the upward and downward movement of the valve needle 1. The actuator is a cylinder. The cylinder moves downward to open the discharge port 32, and moves upward to close the discharge port 32. The structure is simple, reliable, and improves the operating efficiency of the valve needle 1.

[0040] In summary, the specially designed valve needle structure not only enables the ring-shaped glue injection function to improve glue injection efficiency, but also allows for quick disassembly and assembly, facilitating subsequent disassembly and maintenance.

[0041] In summary, the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A hot runner annular nozzle structure, comprising a valve needle, a manifold, and a hot nozzle, wherein one side of the manifold has an inlet connected to an internal flow channel, and the other side of the manifold has a guide hole penetrating the manifold, the guide hole being aligned with the center of the inlet, the radial dimension of the guide hole being smaller than the radial dimension of the inlet, the valve needle being installed in the guide hole, the hot nozzle being installed on the inlet, the center of the hot nozzle forming an end flow channel, and the valve needle penetrating the end flow channel and exiting the hot nozzle, characterized in that: The hot nozzle has a discharge port at the end away from the distributor plate, the valve needle end has a sealing part, the sealing part has a discharge part in the opposite direction of the valve needle, the radial dimension of the discharge part is smaller than that of the sealing part, and the radial dimension of the sealing part is the same as that of the discharge port.

2. The hot runner annular hot nozzle structure according to claim 1, characterized in that: The dispensing section includes a tapered flow channel, the radial dimension of which gradually decreases from the top to the sealing section.

3. The hot runner annular hot nozzle structure according to claim 1, characterized in that: The dispensing section includes at least four notched flow channels, and the bottom of the notched flow channels is a sealing section.

4. The hot runner annular hot nozzle structure according to claim 1, characterized in that: The sealing part is detachably installed at the end of the valve needle.

5. The hot runner annular hot nozzle structure according to claim 4, characterized in that: The sealing material is P20.

6. The hot runner annular hot nozzle structure according to any one of claims 1-5, characterized in that: It also includes a sealing gasket, which is fixed to the outlet. The sealing gasket has a sealing opening at its center, through which the valve needle passes. The radial dimension of the sealing opening is the same as the radial dimension of the sealing part.

7. The hot runner annular hot nozzle structure according to claim 6, characterized in that: The hot nozzle includes a heating cylinder and a dispensing nozzle. The dispensing port is located on the dispensing nozzle, and the dispensing nozzle is detachably mounted on the heating cylinder. The heating cylinder is mounted on the distributor plate.

8. The hot runner annular hot nozzle structure according to claim 6, characterized in that: The sealing gasket is made of silicon nitride ceramic.

9. The hot runner annular hot nozzle structure according to claim 8, characterized in that: It also includes a leak-stopping adhesive and a pressure block. The diverter plate has a sealing port on the back of the adhesive inlet. The leak-stopping adhesive is installed in the sealing port. The height of the leak-stopping adhesive is higher than the height of the sealing port. The pressure block presses the leak-stopping adhesive into the sealing port and fixes it on the diverter plate. The valve needle passes through the pressure block and the leak-stopping adhesive.

10. The hot runner annular hot nozzle structure according to claim 9, characterized in that: It also includes an actuator, in which the end of the valve needle away from the hot nozzle is installed, and the actuator controls the upward and downward movement of the valve needle.

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