Hot nozzle device with combined valve needle
By combining valve needle structures and utilizing titanium alloy needles with low thermal conductivity, the problem of transparent plastic turning white caused by valve needle hot nozzles is solved, ensuring molding efficiency and quality, reducing costs and extending equipment life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-14
- Publication Date
- 2026-03-13
AI Technical Summary
Existing valve needle-type hot nozzles can easily cause excessively high temperatures at the gate when producing food-grade transparent plastics, resulting in whitening of the plastic and affecting the quality of the finished product.
The valve adopts a combined valve needle structure, including a second needle body with low thermal conductivity and a first needle body with high thermal conductivity. The second needle body is made of titanium alloy and is fixed by threaded connection and brazing to ensure stability at high temperature and low temperature contact, and to avoid whitening.
It effectively prevents transparent plastic from turning white at the gate, maintains molding efficiency and quality, reduces costs, and extends equipment lifespan.
Smart Images
Figure CN223989718U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of hot runner technology, and in particular to a hot nozzle device with a combined valve needle. Background Technology
[0002] Hot runners are a key component in injection molds, primarily used to ensure that the plastic in the runner and gate remains molten during injection molding, thereby improving production efficiency and product quality.
[0003] In the existing technology, hot nozzles are also used to prepare food-grade transparent plastics. However, food-grade transparent plastics (such as PET, PPSU, etc.) are more sensitive to processing temperature and shear force, and are prone to degradation or oxidation under high temperature and high shear force. The excessively high temperature of the gate area of the existing valve needle hot nozzle causes the plastic to be overheated at the gate, resulting in local degradation or oxidation, which leads to whitening. Utility Model Content
[0004] To address the aforementioned shortcomings, the purpose of this invention is to propose a hot nozzle device with a combined valve needle, thereby solving the problem of whitening that occurs when using valve needle-type hot nozzles to prepare transparent plastics.
[0005] To achieve this objective, the present invention adopts the following technical solution:
[0006] A hot nozzle device with a combined valve needle includes a combined valve needle, a cylinder, a manifold, and a nozzle body;
[0007] The cylinder is connected to the first surface of the manifold; one end of the nozzle is connected to the second surface of the manifold, and the other end of the nozzle is provided with a nozzle core;
[0008] The combined valve needle includes a first needle body and a second needle body. The axes of the first needle body and the second needle body are concentric. One end of the first needle body is connected to the output end of the cylinder, and the other end is connected to one end of the second needle body. The other end of the second needle body passes through the flow divider, the nozzle body, and the nozzle core in sequence and extends out of the nozzle core. The thermal conductivity of the second needle body is lower than that of the first needle body, and the thermal conductivity of the second needle body is less than 50 W / (m·K).
[0009] The cylinder is used to drive the combined valve needle to move axially.
[0010] Preferably, the length of the second needle body is less than that of the first needle body, and the material of the second needle body is titanium alloy.
[0011] Preferably, the first needle body and the second needle body are connected by threads, the first needle body is provided with internal threads, and the second needle body is provided with external threads that match the internal threads of the first needle body;
[0012] After the first needle body and the second needle body are threaded together, they are fixed by brazing.
[0013] Furthermore, the brazing is copper brazing.
[0014] Preferably, the concentric circles formed by the outer side walls of the first needle body are larger than the concentric circles formed by the outer side walls of the second needle body.
[0015] Preferably, the concentricity between the first needle body and the second needle body is within 0.01 mm.
[0016] Preferably, the channel of the mouthpiece communicates with the inner cavity of the mouthpiece body, and the opening size at the upper end of the mouthpiece matches the inner cavity size of the mouthpiece body;
[0017] A gate is provided between the outer periphery of the nozzle core and the nozzle body, and the gate is used to fix the nozzle core to the inner end of the nozzle body.
[0018] Preferably, it also includes a main nozzle, which is connected to the first surface of the flow divider plate, and the main nozzle and the nozzle body communicate through the flow channel of the flow divider plate.
[0019] Furthermore, the entrance of the main nozzle is hemispherical.
[0020] The technical solution provided by this utility model can include the following beneficial effects:
[0021] The combined valve needle includes a first needle body and a second needle body. The thermal conductivity of the second needle body is lower than that of the first needle body, and the thermal conductivity of the second needle body is less than 50 W / (m·K). That is, the second needle body has a low thermal conductivity. When preparing transparent plastic, the second needle body has a low thermal conductivity and a low temperature, which avoids the plastic from being overheated and effectively prevents the whitening phenomenon on the surface of the transparent plastic. Attached Figure Description
[0022] Figure 1 This is a structural schematic diagram of one embodiment of the present invention.
[0023] Figure 2 This is a side view of one embodiment of the present invention.
[0024] Figure 3 yes Figure 2 Cross-sectional view of AA.
[0025] Figure 4 yes Figure 3 Enlarged view of the Q-axis.
[0026] The components include: cylinder 1, manifold 2, nozzle body 3, combination valve needle 4, first needle body 41, second needle body 42, nozzle core 5, gating nozzle 6, and main injection nozzle 7. Detailed Implementation
[0027] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.
[0028] In the description of this utility model, it should be understood that the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. Furthermore, features defined with "first" and "second" may explicitly or implicitly include one or more of these features, used to distinguish and describe features, without any order or emphasis.
[0029] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0030] A hot nozzle device with a combined valve needle includes a combined valve needle 4, a cylinder 1, a flow divider 2, and a nozzle body 3;
[0031] The cylinder 1 is connected to the first surface of the flow divider 2; one end of the nozzle body 3 is connected to the second surface of the flow divider 2, and the other end of the nozzle body 3 is provided with a nozzle core 5;
[0032] The combined valve needle 4 includes a first needle body 41 and a second needle body 42. The axes of the first needle body 41 and the second needle body 42 are concentric. One end of the first needle body 41 is connected to the output end of the cylinder 1, and the other end is connected to one end of the second needle body 42. The other end of the second needle body 42 passes through the flow divider 2, the nozzle body 3, and the nozzle core 5 in sequence and extends out of the nozzle core 5. The thermal conductivity of the second needle body 42 is lower than that of the first needle body 41, and the thermal conductivity of the second needle body 42 is less than 50 W / (m·K).
[0033] The cylinder 1 is used to drive the combined valve needle 4 to move axially.
[0034] To address the problems existing in the prior art, this technical solution proposes a hot nozzle device with a combined valve needle 4. In existing valve needle type hot nozzle devices, the valve needle used is generally a single piece, mainly made of copper alloy. The main function of the valve needle is to control the opening and closing of the gate through mechanical action. During the injection process, the valve needle moves upward to open the gate, allowing molten plastic to flow into the cavity, that is, the inner cavity of the nozzle core 5. After injection, the valve needle moves downward to close the gate, preventing plastic backflow and realizing injection molding.
[0035] However, food-grade transparent plastics have higher requirements for surface quality. Using existing valve needles will leave white marks on the surface of plastic products. For example, copper alloys have a high thermal conductivity of about 300-400 W / (m·K). This means that copper alloy valve needles can quickly transfer heat to the gate area, resulting in excessively high temperatures at the gate and affecting the quality of the final product. Therefore, it is necessary to select materials with lower thermal conductivity to make valve needles to prevent whitening.
[0036] However, if the valve needle is made of a material with low thermal conductivity, it means that heat is transferred slowly within the valve needle, resulting in untimely heat transfer, affecting molding efficiency, and also affecting the flow rate of the plastic melt in the nozzle 3, making the melt flow unstable and increasing flow resistance. Therefore, this utility model chooses to use the combined valve needle 4, which includes a first needle body 41 and a second needle body 42. The axes of the first needle body 41 and the second needle body 42 are concentric. One end of the first needle body 41 is connected to the output end of the cylinder 1, and the other end is connected to the second needle body 42. The thermal conductivity of the second needle 42 is lower than that of the first needle 41. The material of the first needle 41 is no different from that of the valve needle in the prior art, which can ensure that the plastic melt flows in the hot nozzle without affecting the flow state of the melt. The thermal conductivity of the second needle 42 is lower than that of the first needle 41, ensuring that the second needle 42 with a lower thermal conductivity is in contact with the finished product. The thermal conductivity of the second needle 42 is less than 50 W / (m·K). When in contact with the finished product, the temperature will not be too high, thereby reducing the occurrence of whitening and solving the problem of whitening that occurs when using valve needle type hot nozzles to prepare transparent plastics.
[0037] Preferably, the length of the second needle body 42 is less than that of the first needle body 41, and the material of the second needle body 42 is titanium alloy.
[0038] The second needle body 42 has a thermal conductivity of less than 50 W / (m·K), while the thermal conductivity of titanium alloy is 10-20 W / (m·K). It exhibits excellent corrosion resistance in various environments, especially in humid atmospheres and seawater. This characteristic allows the titanium alloy valve needle to resist chemical erosion during injection molding, maintaining surface integrity and precision. Furthermore, titanium alloy retains its mechanical properties at high temperatures, offering a wide operating temperature range of 450-500℃ for extended periods. In contrast, many materials with low thermal conductivity soften or lose strength at high temperatures. The high-temperature performance of titanium alloy ensures the stability and reliability of the valve needle during high-temperature injection molding.
[0039] Meanwhile, the length of the second needle body 42 is less than the length of the first needle body 41. Titanium alloy has a higher cost, and the plastic melt flows in the nozzle body 3. The lower thermal conductivity of the second needle body 42 reduces the impact on the melt flow. The shorter length of the second needle body 42 compared to the first needle body 41 ensures that the plastic melt flows uniformly in the nozzle body 3, reduces the impact on molding efficiency, and lowers costs. While ensuring that the combined valve needle 4 has the corresponding strength, the temperature at the contact point between the second needle body 42 and the finished product will not be too high.
[0040] In addition, titanium alloys have good fatigue resistance and can maintain a long service life even under cyclic loads. The second needle body 42 will have a certain friction with the nozzle core 5. Using titanium alloys can reduce equipment failure and downtime caused by fatigue fracture.
[0041] Preferably, the first needle body 41 and the second needle body 42 are connected by threads, the first needle body 41 is provided with internal threads, and the second needle body 42 is provided with external threads that match the internal threads of the first needle body 41.
[0042] After the first needle body 41 and the second needle body 42 are threaded together, they are fixed by brazing.
[0043] During the injection molding process, the valve needle in the hot nozzle device will undergo repeated movements. It is necessary to ensure that the first needle body 41 and the second needle are firmly connected. The first needle body 41 and the second needle body 42 are connected by threads. The threaded connection provides initial mechanical fixation with high precision, which can ensure the concentricity and straightness of the combined valve needle 4 during movement and ensure the structural stability of the combined valve needle 4 under high temperature and high pressure environments. Brazing further enhances the strength of the connection, enabling the valve needle to withstand greater mechanical stress during frequent opening and closing movements, further fixing the position of the second needle body 42 and reducing movement deviations caused by loose connections.
[0044] Specifically, the first needle body 41 is provided with an internal thread, and the second needle body 42 is provided with an external thread that matches the internal thread of the first needle body 41. Brazing fills the tiny gap at the connection between the first needle body 41 and the second needle body 42, further improving the sealing performance and preventing the melt from affecting the strength of the connection.
[0045] Furthermore, the brazing is copper brazing.
[0046] It is worth noting that copper or copper alloys are typically used as filler materials in copper soldering. These materials have high melting points, enabling them to form a stronger bond during the soldering process, further enhancing the connection strength between the first needle body 41 and the second needle body 42. Furthermore, because copper has a high melting point, heat distribution is more uniform during soldering, reducing defects caused by localized overheating. This results in relatively fewer soldering defects and more stable soldering quality.
[0047] Preferably, the first needle body 41 is made of copper alloy. Using copper solder can better match the performance of the first needle body 41 and realize the connection between the first needle body 41 and the second needle body 42.
[0048] Preferably, the concentric circles formed by the outer side walls of the first needle body 41 are larger than the concentric circles formed by the outer side walls of the second needle body.
[0049] Specifically, the combined valve needle 4 moves under the drive of the cylinder 1. The concentric circle formed by the outer side wall of the first needle body is larger than the concentric circle formed by the outer side wall of the second needle body. The first needle body is connected to the output end of the cylinder 1. The first needle body is thicker than the second needle body, which can provide higher mechanical strength, reduce deformation and wear under high pressure and high frequency motion, and because the first needle body is thicker, the deformation generated during thermal expansion is relatively small, which can better maintain the coaxiality with the cylinder 1 and reduce the movement deviation caused by thermal expansion.
[0050] Preferably, the concentricity of the first needle body 41 and the second needle body 42 is within 0.01 mm.
[0051] Specifically, the axes of the first needle body 41 and the second needle body 42 are concentric, and the concentricity between the first needle body 41 and the second needle body 42 is within 0.01mm, which can ensure that the combined valve needle 4 maintains extremely high precision during movement and reduce friction and wear caused by the eccentricity of the second needle body 42.
[0052] Preferably, the channel of the mouthpiece 5 communicates with the inner cavity of the mouthpiece body 3, and the opening size at the upper end of the mouthpiece 5 matches the inner cavity size of the mouthpiece body 3;
[0053] A gate 6 is provided between the outer periphery of the nozzle core 5 and the nozzle body 3. The gate 6 is used to fix the nozzle core 5 to the inner end of the nozzle body 3.
[0054] Specifically, a gate insert 6 is fitted onto the nozzle core 5 to ensure a tight fit between the two after assembly, preventing the nozzle core 5 from collapsing during installation and ensuring a seal. Furthermore, the channel of the nozzle core 5 communicates with the inner cavity of the nozzle body 3, and the opening size at the upper end of the nozzle core 5 matches the inner cavity size of the nozzle body 3, forming a unified flow channel. This enables efficient melt delivery and distribution during injection molding, ensuring the quality and efficiency of injection molding. Additionally, the shape design of the opening at the upper end of the nozzle core 5 is completely consistent with the inner cavity of the nozzle body 3, ensuring smooth melt flow within the flow channel, reducing flow resistance and pressure loss caused by shape mismatch, and ensuring precise alignment of the combined valve needle 4 before entry, reducing the risk of collision between the combined valve needle 4 and the nozzle core 5, and minimizing wear.
[0055] Preferably, it also includes a main nozzle 7, which is connected to the first surface of the flow divider 2, and the main nozzle 7 and the nozzle body 3 communicate through the flow channel of the flow divider 2.
[0056] Furthermore, the entrance of the main nozzle 7 is hemispherical.
[0057] Specifically, the main nozzle 7 is connected to the first surface of the flow divider plate 2, meaning that the main nozzle 7 and the flow channel of the flow divider plate 2 are interconnected. The melt flows through the main nozzle 7, through the flow divider plate 2, and to the nozzle body 3, thereby achieving injection molding. The inlet of the main nozzle 7 is hemispherical, ensuring a more balanced flow of the melt in the flow channel and reducing pressure loss. This balanced melt flow helps ensure the uniformity of the plastic melt flow inside, while also reducing the flow resistance of the melt when entering the main nozzle 7, allowing the melt to enter the flow channel more smoothly, reducing stress concentration, and improving the structural stability of the main nozzle 7 under high temperature and high pressure environments.
[0058] In addition, the hemispherical inlet of the main nozzle 7 can reduce the risk of blockage of the melt at the inlet, provide a certain buffer space, reduce downtime caused by blockage, simplify the subsequent cleaning process, reduce maintenance workload, and reduce the maintenance cost of the main nozzle 7.
[0059] The technical principles of this utility model have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of this utility model and should not be construed as limiting the scope of protection of this utility model in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of this utility model without any inventive effort, and these embodiments will all fall within the scope of protection of this utility model.
Claims
1. A hot tip device having a combination valve needle, characterized by: The combination valve needle, the cylinder, the flow distribution plate and the mouthpiece are included. The cylinder is connected to the first surface of the flow distribution plate, and one end of the mouthpiece is connected to the second surface of the flow distribution plate, and the other end of the mouthpiece is internally provided with a mouth core. The combination valve needle includes a first needle body and a second needle body, the axis of the first needle body is concentric with the axis of the second needle body, one end of the first needle body is connected to the output end of the cylinder, and the other end is connected to one end of the second needle body, and the other end of the second needle body sequentially passes through the flow distribution plate, the mouthpiece and the mouth core and extends out of the mouth core. The thermal conductivity of the second needle body is lower than that of the first needle body, and the thermal conductivity of the second needle body is less than 50 W / (m·K). The cylinder is used to drive the axial movement of the combination valve needle.
2. A heat stake device having a combination valve pin according to claim 1, characterised in that: The length of the second needle body is less than that of the first needle body, and the material of the second needle body is titanium alloy.
3. A heat stake apparatus having a combination valve pin according to claim 1, wherein: The first needle body and the second needle body are connected by threads, the first needle body is internally threaded, and the second needle body is externally threaded and matched with the internal threads of the first needle body. After the first needle body and the second needle body are connected by threads, they are fixed by brazing.
4. A heat nozzle assembly having a combination valve needle as defined in claim 3, wherein: The brazing is copper brazing.
5. A heat stake apparatus having a combination valve needle as defined in claim 1, wherein: The concentric circle formed by the outer sidewall of the first needle body is larger than the concentric circle formed by the outer sidewall of the second needle body.
6. A heat stake apparatus having a combination valve needle as defined in claim 1, wherein: The concentricity of the first needle body and the second needle body is within 0.01 mm.
7. A heat stake apparatus having a combination valve needle as defined in claim 1, wherein: The passage of the mouth core communicates with the inner cavity of the mouthpiece, and the opening size of the upper end of the mouth core matches the size of the inner cavity of the mouthpiece. A gate is arranged between the outer periphery of the mouth core and the mouthpiece, and the gate is used to fix the mouth core to the inner cavity end of the mouthpiece.
8. A heat stake apparatus having a combination valve needle as defined in claim 1, wherein: A main nozzle is also included, the main nozzle is connected to the first surface of the flow distribution plate, and the main nozzle and the mouthpiece communicate through the flow channel of the flow distribution plate.
9. A heat nozzle assembly having a combination valve needle as defined in claim 8, wherein: The entrance of the main nozzle is semispherical.