Hot runner device, injection molding equipment and injection molding method

Abstract

The invention discloses a hot runner device, injection molding equipment and an injection molding method, and relates to the technical field of injection molding equipment, the hot runner device comprises a runner assembly and a temperature control device, the runner assembly is provided with a hot runner, and the runner assembly comprises a hot nozzle body, a hot nozzle head and a heating wire; the hot nozzle head is detachably arranged on the hot nozzle main body and defines at least part of a hot runner together, the hot nozzle main body is provided with an inlet communicated with the hot runner, the hot nozzle head is provided with an outlet communicated with the hot runner, and the heating wire is arranged on the hot nozzle head; the temperature control device is electrically connected with the heating wire, and the temperature control device is configured to control the heating wire to work so as to heat the hot nozzle head and maintain the hot nozzle head at a preset temperature when the injection molding equipment is in mold closing, glue injection and pressure maintaining stages; and when the injection molding equipment is in a cooling and mold opening stage, the heating wire is controlled to stop heating or the heating power of the heating wire is reduced, so that the problems of uneven sprue drawing, nozzle blockage, salivation, wire drawing and the like caused by a constant-temperature control mode adopted by a traditional hot runner structure are solved.

Description

Technical Field

[0001] This invention relates to the field of injection molding equipment technology, and in particular to a hot runner device, injection molding equipment and injection molding method. Background Technology

[0002] In related technologies, injection molding equipment typically includes an injection mold and an injection molding machine. The hot runner system within the injection mold usually includes a runner plate, a hot nozzle body, and a hot nozzle head. A heating element is fitted onto the outside of the hot nozzle body. During injection, the heating element is controlled to conduct heat to the hot nozzle body, which then conducts the heat to the hot nozzle head to achieve the required flow temperature for the molten plastic during injection. However, the temperature control precision of the hot nozzle head in this structure is relatively poor, leading to a higher probability of uneven gate rise, nozzle clogging, drooling, and stringing. It is also difficult to balance the consistency of the product within the mold, thus affecting product quality and production stability. Drooling and stringing can even damage the mold. Summary of the Invention

[0003] The main objective of this invention is to provide a hot runner device, injection molding equipment, and injection molding method, which aims to solve the problem of poor temperature control accuracy of existing hot runner nozzles.

[0004] Firstly, to achieve the above objectives, the hot runner device proposed in this invention is applied to injection molding equipment, and the hot runner device includes:

[0005] A flow channel assembly having a hot flow channel, the flow channel assembly including a hot nozzle body, a hot nozzle head and a heating wire, the hot nozzle head being detachably disposed on the hot nozzle body and together defining at least a portion of the hot flow channel, the hot nozzle body having an inlet communicating with the hot flow channel, the hot nozzle head having an outlet communicating with the hot flow channel, and the heating wire being disposed on the hot nozzle head. A temperature control device, electrically connected to the heating wire, is configured as follows: When the injection molding equipment is in the mold closing, injection and holding pressure stages, the heating wire is controlled to work to heat the hot nozzle and maintain it at a preset temperature; When the injection molding equipment is in the cooling and mold opening stage, the heating wire is controlled to stop heating or the heating power of the heating wire is reduced to a preset value.

[0006] In one embodiment, the heating wire is wound around the outer peripheral wall of the hot nozzle in multiple turns, and the multiple turns of the heating wire surround the hot flow channel and are located near the outlet.

[0007] In one embodiment, a limiting groove is provided on the outer peripheral wall of the hot nozzle, and multiple turns of the heating wire are disposed in the limiting groove.

[0008] In one embodiment, the limiting groove is arranged in a ring around the axis of the hot nozzle, and multiple turns of the heating wire are arranged sequentially in the limiting groove along the axis of the hot nozzle. Alternatively, the limiting groove is continuously and at least partially arranged in a double spiral along the axial direction of the hot nozzle on the outer peripheral wall of the hot nozzle, the heating wire is arranged along the limiting groove, and both free ends of the heating wire extend toward the hot nozzle body.

[0009] In one embodiment, the depth of the limiting groove is H, and the value of H satisfies: 1.5mm≤H≤2mm; And / or, the limiting groove is continuously and at least partially spirally arranged on the outer peripheral wall of the hot nozzle along the axial direction of the hot nozzle, and the width of the limiting groove is D, wherein the value of D satisfies: 1.5mm≤D≤1.8mm; And / or, the end of the hot nozzle head away from the hot nozzle body has an end face, and the distance between the groove wall of the limiting groove near the end face and the end face is M, wherein the value of M satisfies: 1mm≤M≤5mm; And / or, the diameter of the end of the hot nozzle head away from the hot nozzle body is N, and the value of N satisfies: 13mm≤N≤35mm.

[0010] In one embodiment, the outer surface of the heating wire is provided with a first insulating layer, and a second insulating layer is provided between the first insulating layer and the groove wall of the limiting groove; And / or, the flow channel assembly further includes a temperature sensing element, which is disposed in the limiting groove and electrically connected to the temperature control device, and the temperature control device detects the temperature value of the hot nozzle through the temperature sensing element; And / or, the flow channel assembly further includes a heat insulation ring and a collar, the heat insulation ring being disposed on the hot nozzle and its inner wall being disposed opposite to the multiple turns of the heating wire, and the collar being sleeved on the hot nozzle and located outside the heat insulation ring.

[0011] In one embodiment, the number of turns of the heating wire wound around the hot nozzle is a, where a satisfies: 2≤a≤8.

[0012] In one embodiment, one of the hot nozzle head and the hot nozzle body is provided with an external thread, and the other is provided with an internal thread that matches the external thread. The hot nozzle head is detachably connected to the hot nozzle body through the external thread and the internal thread. And / or, the outlet of the hot nozzle is configured as a pointed outlet, a large-mouth straight-through outlet, or a needle valve outlet.

[0013] In one embodiment, the device further includes a flow channel plate connected to the hot nozzle body, at least a portion of the hot flow channel is disposed on the flow channel plate, the hot nozzle body is provided with a first heating element, the flow channel plate is provided with a second heating element, and the temperature control device is electrically connected to the first heating element and the second heating element.

[0014] In one embodiment, the temperature control device includes a first temperature control unit and a second temperature control unit, wherein the first temperature control unit is electrically connected to the heating wire, and the second temperature control unit is electrically connected to the first heating element and the second heating element.

[0015] In one embodiment, the flow channel assembly includes a plurality of hot nozzle bodies, each hot nozzle body being provided with a hot nozzle head, and the hot flow channel located on the flow channel plate having a plurality of sub-flow channels, the plurality of hot nozzle bodies being disposed on the flow channel plate and respectively corresponding to and communicating with the plurality of sub-flow channels one by one.

[0016] Secondly, the present invention also provides an injection molding apparatus comprising the hot runner device described in any one of the first aspects.

[0017] In one embodiment, the injection molding equipment further includes an injection mold and an injection molding machine, the runner assembly is disposed on the injection mold, the injection mold has a gate and a cavity, and the injection molding machine is configured to inject melt into the cavity through the runner assembly and the gate.

[0018] In one embodiment, the injection mold includes a moving mold and a fixed mold. Both the moving mold and the fixed mold are provided with cooling water channels. The fixed mold is provided with the gate and a water jacket located at the gate. The moving mold is provided with the cavity. The runner assembly is located in the fixed mold, and at least a portion of the hot runner is located within the water jacket. The cooling water channels and the water jacket are used to transport cooling water to cool the gate and the cavity.

[0019] Thirdly, the present invention also proposes an injection molding method applied to the injection molding equipment described in any one of the second aspects. The injection molding equipment includes a hot runner system and an injection mold. The hot runner system includes a runner plate, a hot nozzle body, and a hot nozzle head, which are sequentially connected and form a hot runner. The hot nozzle body is provided with a first heating element, the runner plate with a second heating element, and the hot nozzle head with a heating wire. The injection mold has a gate, a cavity, and a cooling water channel. The injection molding method includes the following steps: The heating wire is controlled to heat the nozzle to the first preset temperature; The first heating element is controlled to heat the hot nozzle body to a second preset temperature, and the second heating element is controlled to heat the flow channel plate to a third preset temperature; Melt is injected into the hot runner, and the first and second heating elements are controlled to maintain the melt injected into the hot runner in a molten state. The heating wire is controlled to maintain the temperature of the hot nozzle within a preset temperature range. After filling the cavity with melt and completing the pressure holding process, the heating wire is controlled to stop heating or the heating power of the heating wire is reduced to a preset value, and cooling water is injected into the cooling water channel to cool and solidify the melt at the gate and in the cavity.

[0020] In one embodiment, the hot nozzle is further provided with a temperature measuring element electrically connected to the temperature control device. When injecting melt into the hot runner, the steps further include: obtaining the temperature of the hot nozzle; when the current temperature of the hot nozzle exceeds the preset temperature range, or when the temperature measuring element detects a fault, controlling the heating wire on the hot nozzle to stop heating so that the melt in the hot nozzle solidifies.

[0021] The hot runner device proposed in this invention is applied to injection molding equipment. The hot runner device includes a runner assembly and a temperature control device. The runner assembly has a hot runner and includes a hot nozzle body, a hot nozzle head, and a heating wire. The hot nozzle head is detachably mounted on the hot nozzle body and together defines at least a portion of the hot runner. The hot nozzle body has an inlet communicating with the hot runner, and the hot nozzle head has an outlet communicating with the hot runner. The heating wire is mounted on the hot nozzle head. The temperature control device is electrically connected to the heating wire and is configured to: control the heating wire to operate to heat the hot nozzle head and maintain it at a preset temperature during the mold closing, injection, and holding pressure stages of the injection molding equipment; and control the heating wire to stop heating or reduce the heating power of the heating wire to a preset value during the cooling and mold opening stages of the injection molding equipment.

[0022] This setup allows for precise temperature control of the hot runner nozzle according to different operating stages of the injection molding equipment. During mold closing, injection, and holding pressure stages, the temperature control device regulates the heating wire to ensure the nozzle temperature remains at the preset level. This ensures the molten plastic in the hot runner remains in a good flow state, preventing premature solidification and blockage of the hot runner or affecting the filling effect due to insufficient temperature. When the injection molding equipment enters the cooling and mold opening stage, the temperature control device immediately stops the heating wire or reduces its heating power to the preset value, causing the nozzle temperature to drop rapidly. This helps the melt at the mold gate to solidify quickly, forming a reliable seal and preventing drooling and stringing before mold opening and the next mold closing. This reduces plastic waste, avoids mold damage during mold closing, and also ensures the accuracy and stability of the feed during the next injection. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of an embodiment of the injection molding equipment provided by the present invention; Figure 2 A schematic diagram of an embodiment of the hot runner device provided by the present invention; Figure 3 A schematic diagram of another embodiment of the hot runner device provided by the present invention; Figure 4 for Figure 1 A magnified view of the area indicated by arrow A in the middle; Figure 5 for Figure 3 A magnified view of the area indicated by arrow B; Figure 6 A schematic diagram of the structure of the hot nozzle and heating wire in one embodiment of the hot runner device provided by the present invention; Figure 7 A schematic diagram of the structure of the hot nozzle body and the hot nozzle head in one embodiment of the hot runner device provided by the present invention; Figure 8 A schematic diagram of the assembly of the hot nozzle body, hot nozzle head, and heating wire in one embodiment of the hot runner device provided by the present invention; Figure 9 This is a partial structural schematic diagram of an embodiment of the injection molding equipment provided by the present invention; Figure 10 This is a partial structural schematic diagram of another embodiment of the injection molding equipment provided by the present invention; Figure 11 A partial structural schematic diagram of another embodiment of the injection molding equipment provided by the present invention; Figure 12 This is a partial structural schematic diagram of another embodiment of the injection molding equipment provided by the present invention; Figure 13 A schematic diagram of the periodic temperature curve of the nozzle tip in an embodiment of the injection molding equipment provided by the present invention. Figure 14 This is a flowchart of an embodiment of the injection molding method proposed in this invention; Figure 15 This is a flowchart of another embodiment of the injection molding method proposed in this invention.

[0025] Explanation of icon numbers: 100. Injection molding equipment; 1. Hot runner system; 1a. Hot runner; 11. Runner assembly; 111. Hot nozzle body; 111a. Inlet; 1111. First heating element; 112. Hot nozzle head; 1121. Nozzle tip; 1122. End face; 112a. Outlet; 112a1. Pointed outlet; 112a2. Large-nozzle straight-through outlet; 112a3. Needle valve outlet; 112b. Limiting groove; 113. Heating wire; 1131. 1. First insulation layer; 1132. Second insulation layer; 114. Temperature sensing element; 115. Heat insulation ring; 116. Collar ring; 117. Runner plate; 1171. Second heating element; 118. Valve needle; 12. Temperature control device; 121. First temperature control unit; 122. Second temperature control unit; 2. Injection mold; 21. Moving mold; 21a. Cavity; 22. Fixed mold; 2a. Cooling water channel; 22b. Gate; 221. Water jacket; 3. Injection molding machine; 200. Plastic products; 210. Cooling and curing layer.

[0026] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0029] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text implies three parallel solutions. For example, "A and / or B" includes solution A or solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0030] The present invention proposes a hot runner device 1.

[0031] Please see Figures 1 to 5 In one embodiment of the present invention, the hot runner device 1 includes a runner assembly 11 and a temperature control device 12. The runner assembly 11 has a hot runner 1a and includes a hot nozzle body 111, a hot nozzle head 112, and a heating wire 113. The hot nozzle head 112 is detachably disposed on the hot nozzle body 111 and together defines at least a portion of the hot runner 1a. The hot nozzle body 111 has an inlet 111a communicating with the hot runner 1a, and the hot nozzle head 112 has an inlet 111a communicating with the hot runner 1a. The outlet 112a is open, and the heating wire 113 is disposed on the hot nozzle 112. The temperature control device 12 is electrically connected to the heating wire 113 and is configured to: control the heating wire 113 to work to heat the hot nozzle 112 and maintain it at a preset temperature when the injection molding equipment 100 is in the mold closing, injection and holding pressure stage; and control the heating wire 113 to stop heating or reduce the heating power of the heating wire 113 to a preset value when the injection molding equipment 100 is in the cooling and mold opening stage.

[0032] It is understood that in this embodiment, the hot runner device 1 is applied to the injection molding equipment 100. The injection molding equipment 100 typically includes an injection mold 2 and an injection molding machine 3. The hot nozzle body 111 and the hot nozzle head 112 in the runner assembly 11 are connected to form part of the hot runner 1a. When the injection molding equipment 100 is working, the injection molding machine 3 is used to inject melt (molten plastic) into the hot runner 1a of the runner assembly 11. The melt enters the hot nozzle body 111 from the inlet 111a and flows along the hot runner 1a to the hot nozzle head 112, and flows out from the outlet 112a of the hot nozzle head 112 into the cavity of the injection mold 2. After the pressure holding and cooling process, it is molded into a plastic product 200.

[0033] During this process, from the mold closing stage to the holding pressure stage of the injection mold 2, the temperature control device 12 controls the heating wire 113 to heat the hot nozzle 112 to a preset temperature. This preset temperature can be a floating range to ensure that the tip 1121 of the hot nozzle 112 is within the optimal flow temperature range, thereby ensuring product quality. When the injection mold 2 enters the cooling and mold opening stage, the temperature control device 12 controls the heating wire 113 to stop heating or reduce the heating power of the heating wire 113 to a preset value. At this time, the tip 1121 of the hot nozzle 112 cools rapidly, causing the molten plastic at the gate 22b of the injection mold 2 to solidify quickly, preventing drooling or stringing during mold opening. After the molded plastic product 200 is removed from the cavity of the injection mold 2, the injection molding equipment 100 enters the next production cycle. After the injection mold 2 closes, the temperature control device 12 again controls the heating wire 113 to rapidly increase its heating power to heat the hot nozzle 112 to the preset temperature.

[0034] It should be noted that the hot nozzle body 111 and the hot nozzle head 112 have various connection structures to achieve detachability. For example, a threaded connection can be used, with an external thread at the lower end of the hot nozzle body 111 and an internal thread at the upper end of the hot nozzle head 112 that matches the external thread. The hot nozzle head 112 can be fastened to or disassembled from the hot nozzle body 111 by rotating it. Alternatively, a snap-fit ​​connection structure can be used, with a snap protrusion extending radially outward on the outer peripheral wall of the hot nozzle body 111 and an annular groove at the corresponding position on the inner wall of the hot nozzle head 112. During assembly, the hot nozzle head 112 is fitted onto the hot nozzle body 111 and the snap protrusion is snapped into the annular groove to achieve quick connection. During disassembly, axial tension is applied to disengage the snap protrusion from the groove. The configuration can be adapted according to requirements, and no specific limitation is made here.

[0035] Furthermore, the heating wire 113 has multiple installation methods. For example, the heating wire 113 can be directly embedded into the pre-set groove inside the hot nozzle 112, and fixed by high-temperature resistant adhesive or by interference fit to achieve a stable installation. This allows the heating wire 113 to directly heat the hot nozzle 112, reducing heat transfer loss and ensuring precise and controllable melt temperature at the hot nozzle 112. Alternatively, the heating wire 113 can be spirally wound around the outer peripheral wall of the hot nozzle 112, and then covered with a heat insulation protective sleeve. This installation method facilitates the replacement and maintenance of the heating wire 113, while the heat insulation protective sleeve can effectively reduce heat loss to the outside and improve heating efficiency. An embedded structure can also be used, in which the heating wire 113 is pre-embedded inside the hot nozzle 112 during the manufacturing process, so that the heating wire 113 and the hot nozzle 112 form a whole, enhancing the uniformity and stability of heating and avoiding local overheating or insufficient temperature. The specific installation method can be selected according to the structural characteristics of the hot nozzle 112, heating requirements, and manufacturing process, and no specific limitation is made here.

[0036] Furthermore, the temperature control device 12 can take various forms. For example, a PID (proportional-integral-derivative) temperature controller can be used. By comparing the temperature signal of the hot nozzle 112 with the set temperature in real time, the PID algorithm is used to adjust the output power of the heating wire 113 to achieve high-precision closed-loop temperature control. Its temperature control accuracy can reach ±0.5℃, which can effectively avoid the impact of temperature fluctuations on the quality of the melt. Alternatively, an intelligent temperature control module can be selected. This module has a built-in microprocessor and can pre-store the injection molding temperature curves of various materials. During the production process, it automatically calls the corresponding temperature control program according to the type of injection molding material to achieve intelligent control. The system features temperature management and an abnormal temperature alarm function. When the temperature exceeds the set range, it can promptly issue an alarm and cut off the heating power supply to ensure safe operation of the equipment. Alternatively, a zoned temperature control system can be adopted. For a hot runner device 1 with multiple hot nozzles 112, each hot nozzle 112 is equipped with an independent temperature control unit, which can precisely control the temperature of each hot nozzle 112 to meet the differentiated temperature requirements when different cavities or different materials are injected simultaneously. The specific temperature control type can be comprehensively selected based on the complexity of the hot runner device 1, the injection precision requirements, and the level of production automation. No specific limitations are made here.

[0037] Furthermore, the temperature control device 12 can monitor the temperature of the hot nozzle 112 in real time using sensors such as thermocouples or resistance temperature detectors (RTDs). Thermocouples offer fast response and a wide measurement range, making them particularly suitable for temperature detection in high-temperature environments. Their probes can be directly embedded inside the hot nozzle 112 or closely fitted to its outer wall, enabling them to quickly capture minute temperature changes. RTDs, on the other hand, offer high measurement accuracy and stability, indirectly obtaining the temperature of the hot nozzle 112 by measuring the relationship between its resistance value and temperature. After converting the collected temperature signals into electrical signals, these temperature sensors transmit them to the control unit of the temperature control device 12, providing accurate data for subsequent temperature adjustment. The choice of sensor can be made according to requirements and is not specifically limited here.

[0038] This configuration allows for precise temperature control of the hot nozzle 112 according to different operating stages of the injection molding equipment 100. During the mold closing, injection, and holding pressure stages, the temperature control device 12 controls the heating wire 113 to ensure that the temperature of the hot nozzle 112 is maintained at the preset temperature. This ensures that the molten plastic in the hot runner 1a remains in a good flow state, preventing premature solidification and blockage of the hot runner 1a or affecting the filling effect due to insufficient temperature. When the injection molding equipment 100 enters the cooling and mold opening stage, the temperature control device 12 immediately controls the heating wire 113 to stop heating or reduces the heating power of the heating wire 113 to the preset value, causing the temperature of the hot nozzle 112 to drop rapidly. This helps the melt at the mold gate to solidify quickly, forming a reliable seal and preventing stringing and drooling before mold opening and the next mold closing. This reduces plastic waste and ensures the accuracy and stability of the feed during the next injection. It also prevents uneven product gates, nozzle blockage, or even damage to the mold during mold closing.

[0039] The design of the hot nozzle 112 being detachably mounted on the hot nozzle body 111 allows for convenient and quick disassembly and replacement when the hot nozzle 112 is worn, damaged, or needs to be replaced with a different specification to meet different injection molding requirements. This reduces maintenance costs and downtime, and improves the flexibility and production efficiency of the equipment. The heating wire 113 is directly mounted on the hot nozzle 112, enabling direct heating of the hot nozzle 112. This results in high heat conduction efficiency, fast temperature control response, and ensures the uniformity and stability of the temperature of the hot nozzle 112, further improving the consistency of the injection molded product quality. Since the heating wire 113 directly heats the hot nozzle 112, in one embodiment of the invention, the hot nozzle 112 can be made of alloy steel and can be quenched to a hardness of HRC52, which greatly improves wear resistance and corrosion resistance, thereby extending its service life.

[0040] In one implementation, such as Figure 3 , Figure 5 As shown, the heating wire 113 is wound around the outer peripheral wall of the hot nozzle 112 in multiple turns, and the multiple turns of the heating wire 113 surround the hot runner 1a and are positioned near the outlet 112a. It is understood that by winding the heating wire 113 in multiple turns around the outer peripheral wall of the hot nozzle 112, surrounding the hot runner 1a, and positioning it near the outlet 112a, a more concentrated and uniform heating area can be formed in the critical area of ​​the hot nozzle 112 near the outlet 112a. Since the melt is about to enter the mold cavity near the outlet 112a, the temperature stability in this area is crucial to the filling and molding quality of the plastic. The multiple turns increase the contact area between the heating wire 113 and the hot nozzle 112, allowing heat to be transferred more quickly and evenly to the tip 1121 of the hot nozzle 112, ensuring that the molten plastic maintains a suitable temperature and good flowability when entering the gate 22b of the injection mold 2 from the tip 1121.

[0041] Furthermore, in existing technologies, heating the nozzle body 111 via a heating wire and relying on heat conduction to heat the nozzle tip 112 typically results in a temperature error of 5-10℃, which cannot meet the requirements for high-precision temperature control. In this solution, the multi-turn heating wire 113 positioned close to the outlet 112a minimizes heat loss during transfer, allowing the temperature control device 12 to adjust the temperature near the outlet 112a more precisely and efficiently. This avoids excessive temperature gradient changes caused by the distance from the outlet 112a, thereby further ensuring stable output of the plastic melt and consistent product molding during the injection molding process.

[0042] The heating wire 113 can be wound in various ways. For example, it can be wound in a tight spiral, forming a continuous and uniform heating area around the nozzle 112. This method ensures a high degree of contact between the heating wire 113 and the nozzle 112, resulting in uniform heating power distribution per unit area and effectively preventing localized overheating or underheating. Alternatively, it can be wound in a segmented manner. Depending on the temperature requirements of different parts of the nozzle 112, the number of winding turns can be increased in critical areas near the outlet 112a to enhance heating density, while the number of turns can be appropriately reduced in areas far from the outlet 112a. This allows for precise temperature control at different locations of the nozzle 112, meeting the differentiated temperature requirements of complex injection molding processes. Furthermore, a cross-winding method can be used. The cross-distribution of the heating wire 113 further enhances the uniformity of heat transfer, reducing heat distribution dead zones that may result from unidirectional winding and ensuring the stability of the overall temperature field of the nozzle 112. The specific winding method can be adapted to meet specific requirements.

[0043] In one implementation, such as Figure 5 As shown, a limiting groove 112b is provided on the outer peripheral wall of the hot nozzle 112, and multiple turns of heating wire 113 are disposed within the limiting groove 112b. It can be understood that the limiting groove 112b is recessed on the outer side wall of the hot nozzle 112 near the outlet 112a and the tip 1121. When the heating wire 113 is wound within the limiting groove 112b, the inner side wall of the limiting groove 112b can provide radial and circumferential limiting for the heating wire 113, effectively preventing displacement or loosening of the heating wire 113 during long-term heating and cooling thermal expansion and contraction. Furthermore, the limiting groove 112b ensures a tighter fit between the heating wire 113 and the outer peripheral wall of the hot nozzle 112, reducing the gap between them and facilitating rapid heat transfer from the heating wire 113 to the hot nozzle 112 body, thus improving heating efficiency.

[0044] Furthermore, the limiting groove 112b can take various forms. For example, the limiting groove 112b can be an annular groove extending circumferentially along the outer peripheral wall of the hot nozzle 112. The cross-section of the annular groove can be semi-circular, rectangular, or trapezoidal, etc. Alternatively, the limiting groove 112b can also be multiple independent short grooves spaced apart along the axial direction of the hot nozzle 112. A heating wire 113 can be wound in each short groove. Through the synergistic effect of the heating wires 113 in multiple short grooves, precise heating of different axial positions of the hot nozzle 112 can be achieved, meeting the temperature requirements of different areas of the hot nozzle 112 in the axial direction. Or, the limiting groove 112b can also be a spiral groove, with the heating wire 113 wound along the spiral groove. This structure enables the heating wire 113 to form a continuous distribution in both the circumferential and axial directions of the hot nozzle 112, thereby achieving spiral heat transfer on the surface of the hot nozzle 112 and further optimizing the overall temperature uniformity of the hot nozzle 112. Different types of limiting grooves 112b can be selected and designed according to factors such as the specific structure of the hot nozzle 112, heating power requirements, and temperature control accuracy.

[0045] Furthermore, the limiting groove 112b also guides the winding path of the heating wire 113, ensuring that the multiple turns of heating wire 113 are arranged evenly and orderly, avoiding overlap or uneven spacing, and further ensuring the temperature uniformity of the heating area of ​​the hot nozzle 112. In some other embodiments, for segmented winding heating wire 113, multiple independent limiting grooves 112b can be provided at different axial positions on the outer peripheral wall of the hot nozzle 112. Each limiting groove 112b corresponds to a segment of heating wire 113, realizing independent limiting and fixing of different heating segments, meeting the structural requirements of differentiated temperature control. The number of limiting grooves 112b, the number of heating wires 113, and their distribution are not specifically limited here.

[0046] In one implementation, such as Figure 6 As shown, the limiting groove 112b is arranged in a ring around the axis of the hot nozzle 112, and multiple turns of heating wire 113 are arranged sequentially within the limiting groove 112b along the axis of the hot nozzle 112. It can be understood that in this embodiment, the width of the limiting groove 112b extends along the axis of the hot nozzle 112, so that the multiple turns of heating wire 113 are arranged closely together along the axis of the hot nozzle 112, and adjacent turns of heating wire 113 can form interconnected heating areas, allowing for relatively uniform heat transfer in the axial direction of the hot nozzle 112. This avoids insufficient or excessive heating in localized areas, thereby effectively improving the overall temperature uniformity of the hot nozzle 112.

[0047] In one implementation, such as Figure 3 , Figure 5 , Figure 7 , Figure 8As shown, the limiting groove 112b is continuously and at least partially arranged in a double helix along the axial direction of the hot nozzle 112 on the outer peripheral wall of the hot nozzle 112. The heating wire 113 is arranged along the limiting groove 112b, and both free ends of the heating wire 113 extend toward the hot nozzle body 111. It can be understood that in this embodiment, the limiting groove 112b adopts a double helix structure design, which enables the heating wire 113 to form a continuous and uniform helical winding path on the outer peripheral wall of the hot nozzle 112. This design significantly increases the contact area between the heating wire 113 and the outer wall of the hot runner 112, allowing heat to be transferred to the inside of the hot runner 112 more quickly and evenly, thereby further improving the overall temperature uniformity of the hot runner 112. Furthermore, the double-helix structure itself has good stability, effectively preventing the heating wire 113 from shifting or loosening under long-term high-temperature operation, ensuring that the heating wire 113 always remains in the preset heating position, guaranteeing the stability and reliability of the heating effect. Moreover, the double-helix limiting groove 112b allows both free ends of the heating wire 113 to extend towards the hot runner body 111, simplifying the wiring layout and electrical connection process of the heating wire 113, and improving the overall safety and ease of assembly of the hot runner device.

[0048] Furthermore, compared to the hot nozzle 112 with an annular limiting groove 112b, the hot nozzle 112 with a double-helix limiting groove 112b has stronger structural strength. Due to its circumferential distribution, the annular limiting groove 112b weakens the overall structural strength of the hot nozzle 112 to some extent, potentially leading to stress concentration when subjected to injection pressure or thermal stress, thus affecting its service life. In contrast, the double-helix limiting groove 112b, with its helix direction, ensures a continuous distribution of the groove on the outer circumference of the hot nozzle 112, avoiding the formation of a complete annular weakening zone on the same circumferential surface. This significantly enhances the structural stability and deformation resistance of the hot nozzle 112 under high-temperature and high-pressure operating conditions, extending its actual service life. Both free ends of the heating wire 113 extend towards the hot nozzle body 111, facilitating connection between the heating wire 113 and an external power control device, simplifying wiring operations, and resulting in a more rational and compact overall structural layout.

[0049] In one implementation, such as Figure 5As shown, the depth of the limiting groove 112b is H, and the value of H satisfies: 1.5mm ≤ H ≤ 2mm. It should be noted that in this embodiment, the depth H of the limiting groove 112b can be 1.5mm, 1.7mm, 1.9mm, 2mm, or any value within the aforementioned range. When the depth H of the limiting groove 112b is set within this range, it provides a stable mounting space for the 0.5mm diameter heating wire 113, ensuring that the heating wire 113 will not easily come out of the limiting groove 112b during operation, and also avoids excessive weakening of the structural strength of the heating nozzle 112 due to excessive groove depth. The depth of both the annular limiting groove 112b and the double-helix limiting groove 112b can be set within the range of H.

[0050] In one implementation, such as Figure 5 As shown, the limiting groove 112b is continuously and at least partially spirally arranged along the axial direction of the hot nozzle 112 on the outer peripheral wall of the hot nozzle 112. The width of the limiting groove 112b is D, which satisfies the condition: 1.5mm ≤ D ≤ 1.8mm. It should be noted that the limiting groove 112b can be a single spiral or a double spiral structure, which is not limited here. The width value D of the limiting groove 112b can be 1.5mm, 1.6mm, 1.7mm, 1.8mm, or any value within the aforementioned range. This width range is mainly set to accommodate a 0.5mm diameter heating wire 113. When the width D of the limiting groove 112b is within this range, it can provide sufficient space for the heating wire 113 while preventing the groove from being too wide, which would cause the heating wire 113 to wobble significantly within the groove, ensuring that the heating wire 113 can stably adhere to the outer peripheral wall of the hot nozzle 112.

[0051] In one implementation, such as Figure 6 As shown, the end of the hot nozzle 112 away from the hot nozzle body 111 has an end face 1122. The distance M between the groove wall of the limiting groove 112b near the end face 1122 and the end face 1122 satisfies: 1mm ≤ M ≤ 5mm. It should be noted that the value of M can be 1mm, 2mm, 3.5mm, 4.1mm, 5mm, or any value within the aforementioned range. It can be adapted to the heating temperature and heating speed required by the nozzle tip 1121, and no specific limitation is made here.

[0052] In one implementation, such as Figure 6 As shown, the diameter of the end of the hot nozzle 112 furthest from the hot nozzle body 111 is N, and the value of N satisfies: 13mm ≤ N ≤ 35mm. It should be noted that the value of N can be 13mm, 15mm, 20mm, 25mm, 30mm, 35mm, or any value within the aforementioned range. The value can be adapted to the heating efficiency of the hot nozzle 112, the material flow resistance, and its compatibility with different specifications of injection molds 2; no specific limitations are made here.

[0053] In some other embodiments, the aforementioned H, D, M, and N values ​​can be adaptively combined according to requirements. For example, when the M value is 2mm and the N value is 20mm, the H value can be adapted to 1.7mm and the D value to 1.6mm, so as to improve the uniformity of melt flow in the limiting groove 112b while ensuring the structural strength of the hot nozzle 112; or when the M value is 4mm and the N value is 30mm, the H value can be set to 1.9mm and the D value to 1.7mm, thereby balancing heating conduction efficiency and material filling stability. When the limiting groove 112b is set as an annular groove, its width value D is not applicable to the above range. The specific combination method needs to comprehensively consider the characteristics of the injection molding material (such as viscosity and melting point), the precision requirements of the molded product, and the actual working conditions such as the production cycle, which will not be listed one by one here.

[0054] In one implementation, such as Figure 5 As shown, a first insulating layer 1131 is provided on the outer surface of the heating wire 113, and a second insulating layer 1132 is provided between the first insulating layer 1131 and the groove wall of the limiting groove 112b. It should be noted that in this embodiment, the first insulating layer 1131 and the second insulating layer 1132 can be of various types. For example, the first insulating layer 1131 is high-temperature glass fiber covering the outer surface of the heating wire 113, while the second insulating layer 1132 is a magnesium oxide ceramic insulating layer filling the limiting groove 112b. The high-temperature glass fiber has excellent high-temperature resistance and good flexibility, and can closely fit the outer surface of the heating wire 113, effectively blocking the direct contact between the heating wire 113 and the outside world, preventing leakage. At the same time, its good thermal conductivity has little impact on the heating efficiency. The magnesium oxide ceramic insulation layer has extremely high insulation strength and excellent high temperature resistance and thermal conductivity. It is filled between the first insulation layer 1131 and the wall of the limiting groove 112b. On the one hand, it further enhances the overall insulation effect and avoids the heat generated by the heating wire 113 from being directly conducted to the metal body of the hot nozzle 112, causing energy loss. On the other hand, it can make the heat evenly distributed in the limiting groove 112b, reduce local overheating, and thus ensure the uniform heating of the melt by the hot nozzle 112, thereby improving the molding quality of the injection molded product.

[0055] Of course, depending on the actual application scenario and performance requirements, the first insulating layer 1131 can also be made of other high-temperature resistant insulating materials such as polyimide film, and the second insulating layer 1132 can also be made of insulating materials such as alumina ceramic, as long as it can meet the insulation and thermal conductivity requirements of the hot runner device 1 in a high-temperature working environment. No specific limitations are made here. The two insulating layers ensure that the heating wire 113, in a high-temperature, high-pressure working environment, can achieve reliable isolation from itself through the inner insulating layer and form a safe distance from metal components through the outer insulating layer, thereby significantly reducing the risk of leakage and ensuring the safety of equipment operation. The synergistic effect of the two insulating materials in terms of thermal conductivity allows the heat generated by the heating wire 113 to be more effectively guided to the melt, reducing ineffective loss to the hot nozzle 112 body and improving energy utilization efficiency.

[0056] In one implementation, such as Figure 5 As shown, the flow channel assembly 11 also includes a temperature sensing element 114. The temperature sensing element 114 is disposed in the limiting groove 112b and electrically connected to the temperature control device 12. The temperature control device 12 detects the temperature value of the hot nozzle 112 through the temperature sensing element 114. It should be noted that in this embodiment, the temperature sensing element 114 is a thermocouple wire. The thermocouple wire is embedded in the second insulating layer 1132 and connected to the temperature control device 12, which can monitor the temperature change of the hot nozzle 112 in real time during operation. When the temperature sensing element 114 senses that the temperature of the hot nozzle 112 deviates from the preset range, it will immediately feed back the signal to the temperature control device 12. The temperature control device 12 then quickly adjusts the working state of the heating wire 113 according to the feedback information, thereby realizing precise closed-loop control of the temperature of the hot nozzle 112, reducing the lag in temperature detection, and providing reliable data support for the efficient response of the temperature control device 12.

[0057] In addition to thermocouple wires, the temperature sensing element 114 can also use other types of elements such as resistance temperature detectors (RTDs), which can be adapted and set according to requirements, without specific limitations here.

[0058] In one implementation, such as Figure 3 and Figure 5 As shown, the flow channel assembly 11 also includes a heat insulation ring 115 and a collar 116. The heat insulation ring 115 is disposed on the hot nozzle 112 and its inner wall is opposite to the multi-turn heating wire 113. The collar 116 is sleeved on the hot nozzle 112 and located outside the heat insulation ring 115. It should be noted that in this embodiment, the heat insulation ring 115 is attached to the outer wall of the hot nozzle 112 and is made of ceramic material. The ceramic material itself has an extremely low thermal conductivity, which can effectively prevent the heat generated by the heating wire 113 from diffusing to the external environment, further reducing heat loss. The inner wall of the ceramic heat insulation ring 115 is opposite to the multi-turn heating wire 113, so that the heat of the heating wire 113 can be more concentrated on the internal flow channel of the hot nozzle 112, ensuring the temperature stability of the melt during the flow process.

[0059] The collar 116 is fitted around the outside of the heat insulation ring 115. On one hand, it secures and protects the heat insulation ring 115, preventing displacement or damage during assembly or use. On the other hand, the collar 116, made of metal, possesses excellent structural strength, enabling it to form a stable connection with other components of the hot nozzle 112, thus enhancing the structural integrity of the entire flow channel assembly 11. The coordinated arrangement of the heat insulation ring 115 and the collar 116 not only strengthens the heat insulation effect of the hot nozzle 112 but also enhances the overall mechanical performance of the device, ensuring its reliable operation under long-term high-temperature conditions.

[0060] In one embodiment, the number of turns of the heating wire 113 wound on the hot nozzle 112 is 'a', where 'a' satisfies: 2 ≤ a ≤ 8. It is understood that the heating wire 113 can be wound with 2, 4, 5, or 8 turns, adaptable to specific requirements. The number of turns of the heating wire 113 directly affects the heating efficiency and temperature uniformity of the hot nozzle 112. If the number of turns 'a' is less than 2, the heating wire 113 has too few turns, and the generated heat may not be sufficient to cover the internal flow channels of the hot nozzle 112, resulting in uneven heating of the melt within the flow channels. This can lead to localized low temperatures, affecting melt flowability, and may even cause the melt to solidify and block the flow channels. When the number of turns a is greater than 8, the excessive number of turns will cause the heating wire 113 to be distributed too densely on the outer wall of the hot nozzle 112. This will not only increase the electromagnetic interference and heat accumulation between the heating wires 113, which may lead to excessively high local temperatures that could damage the hot nozzle 112 or affect the melt performance, but also increase the assembly difficulty and material cost. At the same time, the excessively dense winding may also cause the heating wire 113 to be arranged irregularly due to space constraints, making it difficult to process the limiting groove 112b, which will affect the stability of the heating effect.

[0061] In one implementation, such as Figure 3 As shown, one of the hot nozzle head 112 and the hot nozzle body 111 is provided with an external thread, and the other is provided with an internal thread that matches the external thread. The hot nozzle head 112 is detachably connected to the hot nozzle body 111 through the external and internal threads. This design makes the assembly and disassembly of the hot nozzle head 112 convenient and efficient, without the need for complex special tools. The hot nozzle head 112 and the hot nozzle body 111 can be quickly separated and tightened by simply rotating. The threaded connection structure design ensures good coaxiality and connection sealing between the hot nozzle head 112 and the hot nozzle body 111, which can effectively prevent the melt from leaking from the connection point during injection molding, ensuring the stability of the melt flow path and the quality of the injection molded product. In addition, the tightness of the screw thread can be appropriately adjusted to adjust the fit between the hot nozzle head 112 and the hot nozzle body 111, further optimizing the heat transfer efficiency, ensuring that the hot nozzle head 112 is heated evenly, and maintaining the stable flow of the melt in the hot runner 1a.

[0062] In one implementation, such as Figures 9 to 12 As shown, the outlet 112a of the hot nozzle 112 is configured as a pointed outlet 112a1, a large-nozzle straight-through outlet 112a2, or a needle valve outlet 112a3. It should be noted that... Figure 9 The hot nozzle 112 in the middle is a pointed outlet 112a1, while Figure 10 The hot nozzle 112 is a large-mouth straight-through outlet 112a2. Figure 11 , Figure 12 The hot nozzle 112 is a needle valve type outlet 112a3. Different types of outlet 112a designs can be adapted to different injection molding process requirements and product structure characteristics.

[0063] Hot nozzles 112 with pointed outlets 112a1 are typically suitable for small precision plastic parts or applications requiring narrow gate feed. Their slender outlet structure reduces melt residue at the gate 22b, lowering the difficulty of subsequent cleaning. It also helps increase the flow rate and pressure of the melt entering the cavity, ensuring the melt fills complex cavities. Hot nozzles 112 with large gate straight-through outlets 112a2 have a larger flow channel cross-sectional area, suitable for producing large plastic parts with high injection molding efficiency requirements. They effectively reduce melt flow resistance, minimize pressure loss, and prevent defects such as material shortages and shrinkage marks caused by insufficient melt flow. Hot nozzles 112 with needle valve outlets 112a3, through the inclusion of a movable valve needle 118 within the flow channel, can precisely control the opening and closing time of the gate 22b, achieving precise control of the melt filling and holding pressure processes, significantly improving product surface quality and dimensional accuracy.

[0064] Figure 11 The valve pin 118 extends beyond the hot runner 112. After injection molding, the valve pin 118 can more thoroughly cut off the melt at the gate 22b, reducing or even eliminating gate marks. This is especially suitable for plastic parts with extremely high requirements for product appearance and where obvious gate marks are not allowed, such as optical lenses and high-gloss shells. The extended valve pin 118 can also assist in ejection to a certain extent, helping the plastic part to be smoothly demolded from the mold. Figure 12 The outlet 112a of the hot nozzle 112 adopts a surface needle valve type outlet 112a3, the end of which is flush with the end of the hot nozzle 112. It is more suitable for occasions where the valve needle 118 does not want to directly contact the cavity surface or the internal structure of the product is more complex and it is inconvenient for the valve needle 118 to extend.

[0065] In one implementation, such as Figure 1 and Figure 2As shown, the hot runner device 1 also includes a flow channel plate 117 connected to the hot nozzle body 111. At least a portion of the hot runner 1a is disposed on the flow channel plate 117. The hot nozzle body 111 is provided with a first heating element 1111, and the flow channel plate 117 is provided with a second heating element 1171. The temperature control device 12 is electrically connected to the first heating element 1111 and the second heating element 1171. It should be noted that in this embodiment, the first heating element 1111 and the second heating element 1171 can be of various types. For example, both the first heating element 1111 and the second heating element 1171 can be heating tubes. For the hot nozzle body 111, the heating tube can be wound in a ring around the outer peripheral wall of the hot nozzle body 111 or embedded inside the hot nozzle body 111 to achieve uniform heating of the hot nozzle body 111. For the flow channel plate 117, the heating tube can be embedded in the flow channel plate 117 to achieve uniform heating of the flow channel plate 117.

[0066] In addition, the first heating element 1111 and the second heating element 1171 can also be heating coils, which are fixed to the outside of the hot nozzle body 111 and the runner plate 117 by a sleeve connection. They are easy to install and disassemble and can quickly heat up the hot runner 1a. Alternatively, the first heating element 1111 and the second heating element 1171 can also be heating rods. Heating rods have high thermal efficiency and temperature control accuracy, and are suitable for injection molding scenarios with strict temperature control requirements.

[0067] Furthermore, the temperature control device 12 can collect the real-time temperature of the areas where the first heating element 1111 and the second heating element 1171 are located through sensors installed on the runner plate 117 and the hot nozzle body 111, respectively. The collected temperature signals are compared and analyzed with the preset target temperature, thereby precisely adjusting the heating power to ensure that the hot runner 1a on the hot nozzle body 111 and the runner plate 117 is always maintained within the set process temperature range. This avoids problems such as melt degradation due to excessively high local temperatures or poor melt fluidity due to excessively low temperatures. The runner plate 117 provides a carrier for the diversion and merging of the hot runner 1a, allowing the melt delivered from the nozzle of the injection molding machine 3 to be evenly distributed to each hot nozzle body 111 through the flow channels in the runner plate 117, ensuring the consistency of cavity filling during multi-cavity injection molding.

[0068] In one implementation, such as Figure 1As shown, the temperature control device 12 includes a first temperature control unit 121 and a second temperature control unit 122. The first temperature control unit 121 is electrically connected to the heating wire 113, and the second temperature control unit 122 is electrically connected to the first heating element 1111 and the second heating element 1171. It should be noted that during the injection molding process, the first heating element 1111 and the second heating element 1171 need to remain operational to prevent the melt from cooling and solidifying within the hot runner 1a, while the heating wire 113 can be selectively activated according to actual process requirements. Furthermore, the first temperature control unit 121 and the second temperature control unit 122 can operate independently, precisely controlling the temperature of the heating wire 113, the first heating element 1111, and the second heating element 1171 respectively. This avoids temperature interference between different heating components, further improving the flexibility and reliability of temperature control in the hot runner device 1, and also helps reduce manufacturing costs.

[0069] In one implementation, such as Figure 2 As shown, the runner assembly 11 includes multiple hot nozzle bodies 111, each hot nozzle body 111 having a hot nozzle head 112. The hot runner 1a located on the runner plate 117 has multiple sub-runners. The multiple hot nozzle bodies 111 are disposed on the runner plate 117 and are respectively connected to the multiple sub-runners one by one. It can be understood that the hot runner 1a on the runner plate 117 has multiple sub-runners, and the inlets 111a of the multiple hot nozzle bodies 111 are connected to the sub-runners. When the injection molding machine 3 injects melt into the runner plate 117, it can flow along the multiple sub-runners to the multiple hot nozzle bodies 111, and finally be injected into the corresponding cavity through the hot nozzle head 112, thereby realizing multi-cavity synchronous injection molding.

[0070] Secondly, the present invention also proposes an injection molding equipment 100, which includes a hot runner device 1 according to any one of the first aspects. The specific structure of the hot runner device 1 is as described in the above embodiments. Since the injection molding equipment 100 adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0071] In one implementation, such as Figure 1 and Figure 4As shown, the injection molding equipment 100 also includes an injection mold 2 and an injection molding machine 3. A runner assembly 11 is disposed on the injection mold 2, which has a gate 22b and a cavity 21a. The injection molding machine 3 is configured to inject melt into the cavity 21a through the runner assembly 11 and the gate 22b. It can be understood that when the injection molding equipment 100 is operating, the injection molding machine 3 injects molten plastic into the cavity 21a through the hot runner 1a of the runner assembly 11 and the gate 22b of the injection mold 2. Because the hot runner nozzle 112 corresponds to the gate 22b and the cavity 21a, and the hot runner device 1 can precisely control the temperature of the melt within the runner, the melt maintains good fluidity and a uniform temperature distribution when entering the cavity 21a, thereby ensuring the quality of the injection-molded product.

[0072] In one implementation, such as Figure 1 and Figure 4 As shown, both the moving mold 21 and the fixed mold 22 are provided with cooling water channels 2a. The fixed mold 22 is provided with a gate 22b and a water jacket 221 located at the gate 22b. The moving mold 21 is provided with a cavity 21a. The runner assembly 11 is located in the fixed mold 22 and at least a portion of the hot runner 112 is located in the water jacket 221. The cooling water channels 2a and the water jacket 221 are used to transport cooling water to cool the gate 22b and the cavity 21a. Understandably, after the injection molding equipment 100 injects and completes the holding pressure, the injection molding machine 3 stops injection and the temperature control device 12 cuts off the power supply to the heating wire 113 or reduces the heating power of the heating wire 113. The cooling water pumped into the cooling water channel 2a of the moving mold 21 and the fixed mold 22 by the injection molding equipment 100 flows along the cooling water channel 2a to rapidly cool the melt at the gate 22b, the melt in the cavity 21a, and the tip 1121 of the hot nozzle 112. The melt in the cavity 21a solidifies upon cooling to form a plastic product 200, and the melt at the gate 22b forms a cooling solidification layer 210 upon cooling. This cooling solidification layer 210 can effectively seal the gate 22b, preventing the melt inside the cavity 21a from running or dripping before it is fully cooled, thereby avoiding quality defects such as product shortages and shrinkage caused by melt dripping, and preventing damage to the injection mold 2.

[0073] The rapid cooling of the hot nozzle 112 also helps to shorten the molding cycle and improve production efficiency. After the melt in the cavity has fully cooled and solidified, the moving mold 21 separates from the fixed mold 22, and the molded product can be ejected by the ejection mechanism, completing a complete injection molding cycle. When entering the next cycle, the temperature control device 12 energizes the heating wire 113 or increases its heating power to rapidly heat it up, so as to melt the cooled and solidified layer 210 at the gate 22b, ensuring that the melt can smoothly pass through the hot nozzle 112 into the cavity. With this setting, the heating wire 113 forms a rapid cooling and heating working mode during the injection molding process. Through the rapid response characteristics of the heating wire 113, the energy waste caused by continuous high temperature is avoided while ensuring that the melt fills the mold smoothly.

[0074] Furthermore, the temperature change rate of the hot nozzle 112 is strictly controlled, effectively reducing thermal stress damage to the nozzle itself and extending its service life. Simultaneously, due to the rapid and stable heating process of the heating wire 113, it ensures that the solidified layer at the gate 22b is uniformly and thoroughly melted in each cycle, avoiding melt flow obstruction caused by incomplete local melting, further guaranteeing the molding accuracy and consistency of the injection molded products. In actual production, this working mode also facilitates integration with the automated control system of the injection molding equipment 100, enabling precise control of the entire injection molding cycle through preset temperature parameters and time points, improving the stability and reliability of the production process.

[0075] Thirdly, please refer to Figures 13 to 15 The present invention also proposes an injection molding method, applied to the injection molding equipment 100 of any of the second aspects. The injection molding equipment 100 includes a hot runner device 1 and an injection mold 2. The hot runner device 1 includes a runner plate 117, a hot nozzle body 111, and a hot nozzle head 112 connected in sequence to form a hot runner 1a. The hot nozzle body 111 is provided with a first heating element 1111, the runner plate 117 is provided with a second heating element 1171, and the hot nozzle head 112 is provided with a heating wire 113. The injection mold 2 has a gate 22b, a cavity 21a, and a cooling water channel 2a. The injection molding method includes the following steps: S10: Control the heating wire 113 to heat the hot nozzle 112 to the first preset temperature; The injection molding equipment 100 is turned on and enters the mold closing state from the mold opening state. Before the injection molding machine 3 injects the melt into the runner plate 117, the hot nozzle 112 needs to be heated to the first preset temperature to prevent the melt from solidifying prematurely in the hot runner 1a during injection.

[0076] S20: Control the first heating element 1111 to heat the hot nozzle body 111 to the second preset temperature, and control the second heating element 1171 to heat the flow channel plate 117 to the third preset temperature; After the hot nozzle 112 is heated to the first preset temperature, the temperature control device 12 heats the hot nozzle body 111 to the second preset temperature via the first heating element 1111, and heats the runner plate 117 to the third preset temperature via the second heating element 1171. This ensures that the temperature within the entire hot runner 1a meets the melt flow requirements, guaranteeing smooth melt transport within the hot runner 1a without viscosity increase or solidification blockage due to excessively low temperature. The first, second, and third preset temperatures are set according to the characteristics of the injection molding material.

[0077] S30: Inject melt into hot runner 1a, control the first heating element 1111 and the second heating element 1171 to maintain the melt injected into hot runner 1a in a molten state, and control the heating wire 113 to maintain the temperature of the hot nozzle 112 within a preset temperature range. After the preheating of all components of the hot runner 1a is completed, the injection molding machine 3 begins to inject melt into the runner plate 117. At this time, the temperature control device 12 continuously monitors and adjusts the output power of the first heating element 1111 and the second heating element 1171. The heating intensity is dynamically adjusted through the real-time feedback temperature signal to ensure that the plastic injected into the hot runner 1a is always kept in a suitable molten state and its viscosity meets the injection filling requirements. At the same time, the heating wire 113 precisely maintains the temperature of the hot nozzle 112 within the range of the optimal flow temperature (first preset temperature) ±1℃.

[0078] S40: After filling the cavity 21a with melt and completing the pressure holding, control the heating wire 113 to stop heating or reduce the heating power of the heating wire 113 to a preset value, and inject cooling water into the cooling water channel 2a so that the melt at the gate 22b and in the cavity 21a cools and solidifies.

[0079] After injection and pressure holding are completed, the temperature control device 12 controls the heating wire 113 to be de-energized, and the cooling water in the cooling water channel 2a cools down the hot nozzle 112, the gate 22b, the cavity 21a and other positions, so that the melt at the gate 22b forms a cooled and solidified layer 210.

[0080] Please refer to Figure 13 The curve represents the temperature change of the nozzle tip 1121 of the hot nozzle 112 throughout the entire injection molding cycle. T1 is the temperature during injection, while T2 is the temperature at mold opening. Taking ABS plastic as an example, the optimal flow temperature (first preset temperature) of the nozzle tip 1121 during injection is 220℃, and the temperature of the nozzle tip 1121 at mold opening is maintained at 160℃. Figure 13In the process, T1 is 220℃, while T2 is 160℃. After the injection mold 2 performs the mold closing action, the heating wire 113 rapidly heats up to 220℃ within 1-5 seconds, so that the cooled and solidified layer 210 at the gate 22b melts quickly, providing a smooth channel for subsequent melt injection. When the injection molding machine 3 completes the melt injection and enters the holding pressure stage, the heating wire 113 continues to be maintained at a temperature range of 220±2℃ (i.e., between 218℃ and 222℃) to ensure that the melt maintains good fluidity during the holding pressure process, thereby effectively transmitting pressure and ensuring the density and dimensional accuracy of the product.

[0081] After the pressure holding period ends, the temperature control device 12 immediately cuts off the power to the heating wire 113 or reduces its heating power to a preset value. Then, the cooling stage begins. Under the action of cooling water in the cooling water channel 2a, the temperature of the nozzle tip 1121 of the hot nozzle 112 rapidly drops from 220℃, typically reaching 160℃ within 3-6 seconds and remaining stable. Simultaneously, the ABS melt at the gate 22b rapidly cools and solidifies due to the temperature drop, forming a reliable seal. This prevents residual melt in the runner from dripping or stringing when the mold opens, avoiding adverse effects on the product appearance and subsequent production. Throughout the injection molding cycle, the temperature change of the nozzle tip 1121 follows a pattern of "rapid heating - stable holding - rapid cooling - constant temperature waiting," achieving precise control of the rapid heating and cooling of the hot nozzle 112. This precise temperature control rhythm ensures stable operation of the injection molding equipment 100, improving injection molding production efficiency and product quality.

[0082] In one embodiment, the hot nozzle 112 is further provided with a temperature sensing element 114 electrically connected to the temperature control device 12, and when injecting melt into the hot runner 1a, the steps further include: S31: Obtain the temperature of the hot nozzle 112. When the current temperature of the hot nozzle 112 exceeds the preset temperature range, or when the temperature sensing element 114 detects a fault, control the heating wire 113 on the hot nozzle 112 to stop heating so that the melt in the hot nozzle 112 solidifies.

[0083] During injection molding, the temperature control device 12 obtains the temperature of the hot nozzle 112 in real time through the temperature sensing element 114. When the temperature value exceeds the first preset temperature ±10℃, taking ABS plastic as an example, if the current temperature of the nozzle tip 1121 exceeds 230℃ or is lower than 190℃, or if the temperature sensing element 114 fails to detect the temperature, the temperature control device 12 cuts off the power supply to the heating wire 113 to stop heating. Under the action of the cooling water in the cooling water channel 2a, the melt in the hot nozzle 112 solidifies to seal the hot nozzle 112, while the other hot nozzles 112 work normally, avoiding the interruption of the entire injection molding production due to the abnormality of a single hot nozzle 112, thus improving the fault tolerance and production reliability of the hot runner device 1.

[0084] The above description is merely an exemplary embodiment of the present invention and does not limit the scope of protection of the present invention. Any equivalent structural transformations made based on the technical concept of the present invention and the contents of the specification and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present invention.

Claims

1. A hot runner device, applied in injection molding equipment, characterized in that, include: A flow channel assembly having a hot flow channel, the flow channel assembly including a hot nozzle body, a hot nozzle head and a heating wire, the hot nozzle head being detachably disposed on the hot nozzle body and together defining at least a portion of the hot flow channel, the hot nozzle body having an inlet communicating with the hot flow channel, the hot nozzle head having an outlet communicating with the hot flow channel, and the heating wire being disposed on the hot nozzle head. A temperature control device, electrically connected to the heating wire, is configured as follows: When the injection molding equipment is in the mold closing, injection and holding pressure stages, the heating wire is controlled to work to heat the hot nozzle and maintain it at a preset temperature; When the injection molding equipment is in the cooling and mold opening stage, the heating wire is controlled to stop heating or the heating power of the heating wire is reduced to a preset value.

2. The hot runner device as described in claim 1, characterized in that, The heating wire is wound around the outer peripheral wall of the hot nozzle in multiple turns, and the multiple turns of the heating wire surround the hot flow channel and are located near the outlet.

3. The hot runner device as described in claim 2, characterized in that, The outer peripheral wall of the hot nozzle is provided with a limiting groove, and multiple turns of the heating wire are disposed in the limiting groove.

4. The hot runner device as described in claim 3, characterized in that, The limiting groove is arranged in a ring around the axis of the hot nozzle, and multiple turns of the heating wire are arranged sequentially in the limiting groove along the axis of the hot nozzle. Alternatively, the limiting groove is continuously and at least partially arranged in a double spiral along the axial direction of the hot nozzle on the outer peripheral wall of the hot nozzle, the heating wire is arranged along the limiting groove, and both free ends of the heating wire extend toward the hot nozzle body.

5. The hot runner device as described in claim 3, characterized in that, The depth of the limiting groove is H, and the value of H satisfies: 1.5mm≤H≤2mm; And / or, the limiting groove is continuously and at least partially spirally arranged on the outer peripheral wall of the hot nozzle along the axial direction of the hot nozzle, and the width of the limiting groove is D, wherein the value of D satisfies: 1.5mm≤D≤1.8mm; And / or, the end of the hot nozzle head away from the hot nozzle body has an end face, and the distance between the groove wall of the limiting groove near the end face and the end face is M, wherein the value of M satisfies: 1mm≤M≤5mm; And / or, the diameter of the end of the hot nozzle head away from the hot nozzle body is N, and the value of N satisfies: 13mm≤N≤35mm.

6. The hot runner device as described in claim 3, characterized in that, The outer surface of the heating wire is provided with a first insulating layer, and a second insulating layer is provided between the first insulating layer and the groove wall of the limiting groove; And / or, the flow channel assembly further includes a temperature sensing element, which is disposed in the limiting groove and electrically connected to the temperature control device, and the temperature control device detects the temperature value of the hot nozzle through the temperature sensing element; And / or, the flow channel assembly further includes a heat insulation ring and a collar, the heat insulation ring being disposed on the hot nozzle and its inner wall being disposed opposite to the multiple turns of the heating wire, and the collar being sleeved on the hot nozzle and located outside the heat insulation ring.

7. The hot runner device as described in claim 2, characterized in that, The number of turns of the heating wire wound around the hot nozzle is a, where a satisfies: 2≤a≤8.

8. The hot runner device as claimed in claim 1, characterized in that, The hot nozzle head and the hot nozzle body are provided with an external thread on one of them and an internal thread that matches the external thread on the other. The hot nozzle head is detachably connected to the hot nozzle body through the external thread and the internal thread. And / or, the outlet of the hot nozzle is configured as a pointed outlet, a large-mouth straight-through outlet, or a needle valve outlet.

9. The hot runner device as claimed in any one of claims 1 to 8, characterized in that, It also includes a flow channel plate connected to the hot nozzle body, at least a portion of the hot flow channel is disposed on the flow channel plate, the hot nozzle body is provided with a first heating element, the flow channel plate is provided with a second heating element, and the temperature control device is electrically connected to the first heating element and the second heating element.

10. The hot runner device as claimed in claim 9, characterized in that, The temperature control device includes a first temperature control unit and a second temperature control unit. The first temperature control unit is electrically connected to the heating wire, and the second temperature control unit is electrically connected to the first heating element and the second heating element.

11. The hot runner device as claimed in claim 9, characterized in that, The flow channel assembly includes a plurality of hot nozzle bodies, each hot nozzle body is provided with a hot nozzle head, and the hot flow channel located on the flow channel plate has a plurality of sub-flow channels. The plurality of hot nozzle bodies are disposed on the flow channel plate and are respectively connected to the plurality of sub-flow channels one by one.

12. An injection molding machine, characterized in that, Includes the hot runner device as described in any one of claims 1 to 11.

13. The injection molding equipment as described in claim 12, characterized in that, The injection molding equipment also includes an injection mold and an injection molding machine. The runner assembly is disposed on the injection mold. The injection mold has a gate and a cavity. The injection molding machine is configured to inject melt into the cavity through the runner assembly and the gate.

14. The injection molding equipment as described in claim 13, characterized in that, The injection mold includes a moving mold and a fixed mold. Both the moving mold and the fixed mold are provided with cooling water channels. The fixed mold is provided with the gate and a water jacket located at the gate. The moving mold is provided with the cavity. The runner assembly is located in the fixed mold and at least a portion of the hot runner is located in the water jacket. The cooling water channels and the water jacket are used to transport cooling water to cool the gate and the cavity.

15. An injection molding method, characterized in that, An injection molding equipment as described in any one of claims 12 to 14, the injection molding equipment comprising a hot runner system and an injection mold, the hot runner system comprising a runner plate, a hot nozzle body, and a hot nozzle head connected in sequence to form a hot runner, the runner plate having a first heating element, the hot nozzle body having a second heating element, and the hot nozzle head having a heating wire, the injection mold having a gate, a cavity, and a cooling water channel, the injection molding method comprising the following steps: The heating wire is controlled to heat the nozzle to the first preset temperature; The first heating element is controlled to heat the hot nozzle body to a second preset temperature, and the second heating element is controlled to heat the flow channel plate to a third preset temperature; Melt is injected into the hot runner, and the first and second heating elements are controlled to maintain the melt injected into the hot runner in a molten state. The heating wire is controlled to maintain the temperature of the hot nozzle within a preset temperature range. After filling the cavity with melt and completing the pressure holding process, the heating wire is controlled to stop heating or reduce the heating power of the heating wire, and cooling water is injected into the cooling water channel to cool and solidify the melt at the gate and in the cavity.

16. The injection molding method as described in claim 15, characterized in that, The hot nozzle is also equipped with a temperature measuring element electrically connected to the temperature control device. When injecting melt into the hot runner, the injection molding method further includes the following steps: The temperature of the hot nozzle is obtained. When the current temperature of the hot nozzle exceeds the preset temperature range, or when the temperature sensing element detects a malfunction, the heating wire on the hot nozzle is controlled to stop heating so that the melt inside the hot nozzle solidifies.

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