Hot runner system, stack mold

Abstract

This invention discloses a hot runner system and a stacked mold. The hot runner system includes a first hot runner assembly and a second hot runner assembly. The first hot runner assembly is disposed in the fixed mold, and its runner is connected to the gate of the second cavity. The second hot runner assembly is disposed in the intermediate mold, and its runner is connected to the gate of the first cavity. When the moving mold, intermediate mold, and fixed mold of the stacked mold are closed, the runners of the first and second hot runner assemblies are connected to form a continuous runner structure, and the molten injection material enters the runner of the second hot runner assembly through the runner of the first hot runner assembly. This invention, by optimizing the arrangement and feeding path of the hot runner system, maintains the high output advantage of the stacked mold while effectively improving the balance, stability, and reliability of the injection molding process.

Description

Technical Field

[0001] This invention relates to the field of injection mold technology, and in particular to a hot runner system and a stacked mold. Background Technology

[0002] Injection molding is one of the most widely used processes in plastic product processing. With the continuous growth in demand for plastic products, the injection molding industry has placed higher demands on production efficiency, cost control, and equipment resource utilization. To increase output per unit time and reduce part costs, stack molds (also known as multi-layer molds or mack molds) are widely used. These molds achieve a multiple increase in output per injection cycle based on the number of cavity layers by setting multiple stacked cavities between the moving and stationary molds, while simultaneously improving equipment utilization without significantly increasing the clamping force of the injection molding machine.

[0003] However, existing stacked molds typically consist of a moving mold, a middle mold, and a fixed mold, and often employ a design where the hot runner is concentrated in the middle mold for centralized injection. In this design, the hot runner is centrally located in the middle mold, simultaneously supplying plastic to the injection cavities distributed on both sides. The applicant has found that when different injection molded parts are produced in the injection cavities on both sides of the middle mold, the geometry, runner length, and distribution of the injection cavities differ, resulting in inconsistent flow resistance of the molten plastic in different injection cavities. This leads to uneven plastic distribution due to the simultaneous injection from both sides of the middle mold. Furthermore, the centralized arrangement of the hot runner in the middle mold increases the mold weight, complicates mold installation and maintenance, and is prone to eccentricity, wear, and other malfunctions, thus limiting the mold's production efficiency and service life. Summary of the Invention

[0004] To address the technical problems in existing stacked molds, which typically employ a centralized injection design in the middle mold, resulting in excessive mold weight and complex installation and maintenance, the present invention aims to provide a hot runner system and a stacked mold that effectively optimizes the layout of the hot runner system, reduces the structural burden on the mold, and improves the balance, stability, and reliability of the injection molding process, thereby enhancing the overall production efficiency of the mold.

[0005] The objective of this invention is achieved through the following technical solution: In a first aspect, the present invention provides a hot runner system for a stacked mold having a moving mold, a middle mold, and a fixed mold, wherein the moving mold and the middle mold enclose to form a first cavity when the mold is closed, and the middle mold and the fixed mold enclose to form a second cavity when the mold is closed, the hot runner system comprising: A first hot runner assembly is disposed in a fixed mold, and the runner of the first hot runner assembly is connected to the gate of the second cavity. The second hot runner assembly is disposed in the middle mold, and the runner of the second hot runner assembly is connected to the gate of the first cavity; In the case of the moving mold, middle mold and fixed mold of the stacked mold being closed, the flow channel of the first hot runner assembly is connected to the flow channel of the second hot runner assembly to form a continuous flow channel structure, and the molten injection material enters the flow channel of the second hot runner assembly through the flow channel of the first hot runner assembly.

[0006] In conjunction with the first aspect, the present invention also provides a first specific embodiment of the first aspect, wherein, preferably, the flow channels of the first hot runner assembly and the second hot runner assembly are respectively provided with control valves, and the control valves are capable of switching between a first position and a second position; When the control valve is in the first position, it connects the flow channel of the first hot runner assembly with the flow channel of the second hot runner assembly; when the control valve is in the second position, it blocks the connection between the flow channel of the first hot runner assembly and the flow channel of the second hot runner assembly.

[0007] In conjunction with the first aspect, the present invention also provides a second specific embodiment of the first aspect. Preferably, the control valve adopts a needle valve type hot nozzle structure, specifically, the flow channel of the first hot runner assembly is provided with a plurality of first needle valve type connecting hot nozzles, and the flow channel of the second hot runner assembly is provided with a plurality of second needle valve type connecting hot nozzles. During mold closing, the first needle valve type connecting hot nozzle connects to the corresponding second needle valve type connecting hot nozzle, so that the flow channel of the first hot runner assembly is connected to the flow channel of the second hot runner assembly.

[0008] In conjunction with the first aspect, the present invention also provides a third specific embodiment of the first aspect, wherein, preferably, the first hot runner assembly comprises: A first manifold plate is disposed on the fixed mold, and the first manifold plate is provided with a feeding hot nozzle; Multiple first needle valve type injection hot nozzles are disposed on the first manifold, and the first needle valve type injection hot nozzles are connected to the first manifold channel inside the first manifold; the first needle valve type injection hot nozzles are connected to the gate of the first cavity. Multiple first needle valve type hot nozzles are disposed on the first manifold, and the first needle valve type hot nozzles are connected to the first manifold channel inside the first manifold; when the mold is closed, the first needle valve type hot nozzles are connected to the flow channel of the second hot runner assembly.

[0009] In conjunction with the first aspect, the present invention also provides a fourth specific embodiment of the first aspect. Preferably, the first diverter plate is an integral structure, which includes a connecting part located in the middle and two diverter parts respectively disposed at both ends of the connecting part; the connecting part is generally strip-shaped and has a main channel inside, and the connecting part is connected to the feed hot nozzle; Each branch section has a branch flow channel inside, and the main flow channel and the two branch flow channels together form the first branch flow channel of the first branch plate; The diversion section has an overall H-shaped structure, including two support arms spaced apart from each other and a transverse connecting arm connecting the two support arms. The end of the connecting section is connected to the transverse connecting arm of the diversion section. One of the first needle valve type connecting hot nozzles is correspondingly set on the transverse connecting arm of the flow divider and is located at the connection between the transverse connecting arm and the connecting part; multiple first needle valve type connecting hot nozzles are distributed around the first needle valve type connecting hot nozzle on the two support arms.

[0010] In conjunction with the first aspect, the present invention also provides a fifth specific embodiment of the first aspect. Preferably, the second hot runner assembly includes a plurality of second manifolds, a plurality of second needle valve injection hot nozzles and a plurality of second needle valve connecting hot nozzles, with one second manifold corresponding to one first needle valve connecting hot nozzle. The second needle valve injection hot nozzle is disposed on the second manifold, and the second needle valve injection hot nozzle is connected to the second manifold channel inside the second manifold; the second needle valve injection hot nozzle is connected to the gate of the second cavity; The second needle valve type hot nozzle is disposed on the second manifold, and the second needle valve type hot nozzle is connected to the second manifold channel inside the second manifold; when the mold is closed, the second needle valve type hot nozzle is connected to the flow channel of the first hot runner assembly.

[0011] In conjunction with the first aspect, the present invention also provides a sixth specific embodiment of the first aspect. Preferably, the second diverter plate is in the form of an H-shaped structure, including two support arms spaced apart from each other and a transverse connecting arm connecting the two support arms. A second needle valve type connecting hot nozzle is correspondingly set on the transverse connecting arm of the second manifold, and multiple second needle valve type injection hot nozzles are distributed around the second needle valve type connecting hot nozzle on the two support arms of the second manifold.

[0012] Secondly, the present invention also provides a stacked mold, the stacked mold comprising the hot runner system described in the first aspect and the first to sixth specific embodiments of the first aspect.

[0013] Thirdly, the present invention also provides a stacked mold, the stacked mold comprising a moving mold, a middle mold and a fixed mold arranged in sequence and capable of opening and closing relative to each other; The moving mold includes a first mold core, the middle mold includes a second mold core and a third mold core, and the fixed mold includes a fourth mold core; the first mold core and the second mold core form a first cavity for injection molding when the mold is closed; the third mold core and the fourth mold core form a second cavity for injection molding when the mold is closed. The fixed mold is provided with a first hot runner assembly, the runner of the first hot runner assembly is connected to the gate of the second cavity; the first hot runner assembly has a feed nozzle connected to an external injection molding machine; The middle mold is provided with a second hot runner assembly, and the runner of the second hot runner assembly is connected to the gate of the first cavity; During mold closing, the flow channels of the first hot runner assembly and the second hot runner assembly are connected to form a continuous flow channel structure, and the molten injection material enters the flow channel of the second hot runner assembly through the flow channel of the first hot runner assembly.

[0014] In conjunction with the third aspect, the present invention also provides a first specific embodiment of the third aspect, wherein, preferably, the intermediate mold is connected to a load-bearing structure, the load-bearing structure being configured to fix the intermediate mold to the frame or moving mechanism of the injection molding machine; The load-bearing structure includes a support plate, two bases, and two fixing blocks; the support plate is used to connect the frame or moving mechanism of the injection molding machine; the two bases are connected to the support plate, and the two bases are respectively spaced apart on both sides of the surface of the support plate; the bases are connected to adjusting pads; the two fixing blocks are respectively connected to the two bases, and the fixing blocks are bolted to the intermediate mold.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects: This invention provides a hot runner system for a stacked mold having a moving mold, a middle mold, and a fixed mold. The moving mold and the middle mold close together to form a first cavity, and the middle mold and the fixed mold close together to form a second cavity. The hot runner system includes a first hot runner assembly and a second hot runner assembly. The first hot runner assembly is disposed in the fixed mold, and its runner is connected to the gate of the second cavity. The second hot runner assembly is disposed in the middle mold, and its runner is connected to the gate of the first cavity. When the moving mold, middle mold, and fixed mold of the stacked mold are closed, the runners of the first hot runner assembly and the second hot runner assembly are connected to form a continuous runner structure, and the molten injection material enters the runner of the second hot runner assembly through the runner of the first hot runner assembly.

[0016] 1. This invention effectively optimizes the hot runner layout and material supply method of stacked molds by dividing the hot runner system into a first hot runner component and a second hot runner component, forming a continuous runner structure in the mold-closed state. This improves the balance of multi-cavity injection molding. In traditional centralized injection design, different cavities are prone to inconsistent flow resistance of molten plastic due to differences in geometry, runner length, and distribution position, resulting in uneven injection. With the solution of this invention, the molten injection material flows into the second hot runner component through the first hot runner component and is then distributed to each cavity sequentially, achieving more uniform material supply to each cavity and improving mold filling balance and product molding quality.

[0017] 2. This invention significantly reduces the structural complexity and overall weight of the middle mold by distributing the hot runner system between the fixed mold and the middle mold. Compared with the traditional method of centrally arranging hot runners in the middle mold, this solution reduces the overall weight of the mold, facilitating mold installation, disassembly, and maintenance; at the same time, it reduces the risk of middle mold eccentricity, wear, and failure, and improves the service life and operational stability of the mold.

[0018] 3. The continuous flow channel structure formed by this invention allows molten plastic to be sequentially delivered to each cavity through a unified feeding path, ensuring flow continuity while also taking into account the independent feeding characteristics of each cavity. This not only ensures stable molding of multi-layer cavities when producing injection molded parts of different geometries or sizes, but also improves the flexibility and adaptability of mold design, providing technical support for the production of diversified products.

[0019] In summary, by optimizing the layout and material supply path of the hot runner system, this invention maintains the high output advantage of stacked molds while effectively improving the balance, stability, and reliability of the injection molding process. This results in improved overall mold production efficiency, reduced unit part costs, and extended mold lifespan.

[0020] Furthermore, the technical solution of the present invention is also applicable to stacked molds configured with this hot runner system, thereby further optimizing the overall performance of the stacked mold. Attached Figure Description

[0021] Figure 1 A schematic diagram of a hot runner system provided by the present invention; Figure 2 A schematic diagram of the EE cross-section of a hot runner system provided by the present invention; Figure 3 A schematic diagram of the FF cross-section of a hot runner system provided by the present invention; Figure 4 A cross-sectional schematic diagram of a stacked mold provided by the present invention; In the picture: 100 - First hot runner assembly, 110 - First manifold plate, 120 - Feed nozzle, 130 - First needle valve injection nozzle, 140 - First needle valve connecting nozzle; 200 - Second hot runner assembly, 210 - Second manifold, 220 - Second needle valve injection nozzle, 230 - Second needle valve connecting nozzle; 10 - Moving mold, 20 - Middle mold, 30 - Fixed mold. Detailed Implementation

[0022] To facilitate understanding of the present invention, the technical solutions and advantages of the invention will be further described in detail below with reference to the accompanying drawings and embodiments. Any mechanisms or methods not elaborated in this invention can be referred to in the prior art. The specific structures and features of the present invention are illustrated below by way of example and should not be construed as limiting the present invention in any way. Furthermore, any of the technical features mentioned below (including implicit or disclosed features), as well as any technical features directly shown or implied in the figures, can be arbitrarily combined or deleted among these technical features to form more other embodiments that may not be directly or indirectly mentioned in this invention. The accompanying drawings show preferred embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of the present invention.

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.

[0024] In the following description, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0025] Furthermore, in this application, directional terms such as "upper," "lower," "left," "right," "horizontal," and "vertical" are defined relative to the indicated placement of components in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the placement of components in the drawings. In this application, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can refer to a mechanical or physical connection. It can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium. It can also be understood as physical contact and electrical conduction between components, or as a form of connection between different components in a circuit structure via physical lines capable of transmitting electrical signals, such as PCB copper foil or wires.

[0026] Currently, injection molding is one of the most widely used molding processes in the plastics product processing industry. With the expanding application of plastic products in packaging, daily necessities, and industrial products, the market demand for plastic products continues to grow, thus placing higher demands on production efficiency, cost control, and equipment resource utilization in the injection molding process.

[0027] Against this backdrop, stacked molds have gradually become an important technical means to improve injection molding production efficiency. Stacked molds, by setting up a multi-layered cavity structure between the moving and stationary molds, allow the injection molding machine to simultaneously mold multiple parts in a single injection cycle. This results in a near-multiplicative increase in part output per unit time with the increase in the number of cavity layers, without significantly increasing the clamping force of the injection molding machine. This structure can significantly improve the utilization rate of injection molding equipment and effectively reduce the production cost of individual parts, thus becoming an important technical direction for solving the problem of limited production efficiency of traditional single-layer molds.

[0028] However, most existing stack molds adopt a standard stack mold structure, with their injection system typically concentrated in the middle mold area, allowing injection from the middle mold to both side cavities simultaneously. When stack molds are used to produce parts with different front and rear mold structures or product shapes, this concentrated injection method often struggles to ensure injection balance between cavities. Furthermore, because the hot runner system is centrally located in the middle mold area, the middle mold structure is quite heavy, increasing the overall structural load on the mold and causing significant inconvenience for installation, disassembly, and maintenance during actual production. It is also prone to problems such as eccentricity and wear due to uneven stress, thus affecting the mold's service life and production stability.

[0029] Therefore, this application provides a hot runner system for a stacked mold having a moving mold, a middle mold, and a fixed mold. The moving mold and the middle mold close together to form a first cavity, and the middle mold and the fixed mold close together to form a second cavity. The hot runner system includes a first hot runner assembly and a second hot runner assembly. The first hot runner assembly is disposed in the fixed mold, and its runner is connected to the gate of the second cavity. The second hot runner assembly is disposed in the middle mold, and its runner is connected to the gate of the first cavity. When the moving mold, middle mold, and fixed mold of the stacked mold are closed, the runners of the first hot runner assembly and the second hot runner assembly are connected to form a continuous runner structure, and the molten injection material enters the runner of the second hot runner assembly through the runner of the first hot runner assembly.

[0030] This invention optimizes the layout and material supply path of the hot runner system, maintaining the high output advantage of stacked molds while effectively improving the balance, stability, and reliability of the injection molding process. This results in improved overall mold production efficiency, reduced unit part costs, and extended mold lifespan.

[0031] Figure 1 This is a schematic diagram of the structure of the hot runner system provided in the embodiments of this application, as shown below. Figure 1 As shown, this application embodiment provides a hot runner system for a stacked mold having a moving mold, a middle mold, and a fixed mold. The moving mold and the middle mold close together to form a first cavity, and the middle mold and the fixed mold close together to form a second cavity. Specifically, the hot runner system includes a first hot runner assembly 100 and a second hot runner assembly 200. The first hot runner assembly 100 is disposed in the fixed mold, and its runner is connected to the gate of the second cavity. The second hot runner assembly 200 is disposed in the middle mold, and its runner is connected to the gate of the first cavity. When the moving mold, middle mold, and fixed mold of the stacked mold are closed, the runners of the first hot runner assembly 100 and the second hot runner assembly 200 are connected to form a continuous runner structure, and the molten injection material enters the runner of the second hot runner assembly 200 through the runner of the first hot runner assembly 100.

[0032] In this embodiment, the hot runner system includes a first hot runner assembly 100 and a second hot runner assembly 200. The first hot runner assembly 100 is disposed in the fixed mold, and its runner is connected to the gate of the second cavity for conveying molten injection molding material from the injection molding machine to the second cavity. The second hot runner assembly 200 is disposed in the intermediate mold, and its runner is connected to the gate of the first cavity for conveying molten injection molding material to the first cavity.

[0033] Furthermore, when the stacked mold is in the closed state, the moving mold, the middle mold, and the fixed mold are in close contact with each other, and the flow channels of the first hot runner assembly 100 and the second hot runner assembly 200 are structurally connected to each other, thereby forming a continuous flow channel structure. Through this continuous flow channel structure, the molten injection molding material can first flow through the first hot runner assembly 100 located in the fixed mold, and further enter the second hot runner assembly 200 located in the middle mold, and then be distributed to the first cavity for injection molding through the second hot runner assembly 200.

[0034] Through the above structural design, the hot runner system in the stacked mold is no longer concentrated in the middle mold, but is instead arranged separately in the fixed mold and the middle mold, forming a connected material supply channel when the mold is closed. This ensures the continuous delivery of molten injection material between different cavities and makes the material supply path of each cavity more reasonable, thereby improving the mold filling stability during multi-cavity injection molding.

[0035] Furthermore, by placing the first hot runner assembly 100 in the fixed mold and the second hot runner assembly 200 in the intermediate mold, the hot runner system is distributed in the mold structure, which helps to reduce the complexity of the internal structure of the intermediate mold, reduce the overall weight of the intermediate mold, facilitate the assembly and maintenance of the mold, and improve the operational stability of the stacked mold in the long-term injection molding process.

[0036] like Figure 2 As shown, in one specific embodiment, the flow channels of the first hot runner assembly 100 and the second hot runner assembly 200 are respectively provided with control valves, which can switch between a first position and a second position. When the control valve is in the first position, the flow channel of the first hot runner assembly 100 is connected to the flow channel of the second hot runner assembly 200; when the control valve is in the second position, the connection between the flow channel of the first hot runner assembly 100 and the flow channel of the second hot runner assembly 200 is blocked.

[0037] Specifically, control valves are respectively provided in the flow channels of the first hot runner assembly 100 and the second hot runner assembly 200. The control valves are configured to switch between a first position and a second position to adjust the flow channel communication state between the first hot runner assembly 100 and the second hot runner assembly 200.

[0038] Specifically, when both control valves are in the first position, the flow channels of the first hot runner assembly 100 and the second hot runner assembly 200 are in communication. At this time, the molten injection material can flow along the flow channel of the first hot runner assembly 100 and further enter the flow channel of the second hot runner assembly 200, thereby conveying the molten injection material to the first cavity through the second hot runner assembly 200. In this state, the hot runner system forms a continuous feeding channel, enabling the molten injection material to be sequentially conveyed to cavities of different layers, achieving synchronous injection molding of multiple cavities.

[0039] When any control valve is switched to the second position, it blocks the flow channel, cutting off the connection between the flow channels of the first hot runner assembly 100 and the second hot runner assembly 200. In this state, the molten injection material flows only within its respective hot runner assembly, thus making the material supply between different hot runner assemblies independent. In this way, the flow channel connectivity can be adjusted according to different injection molding conditions. For example, during mold debugging, single-cavity production, or maintenance, the isolation of local flow channels can be achieved by closing the corresponding control valve.

[0040] By setting switchable control valves in the first hot runner assembly 100 and the second hot runner assembly 200, not only can flexible switching between continuous runner structure and independent runner structure be realized, but the adaptability of the hot runner system under different production conditions can also be improved, thereby enhancing the control accuracy and operational stability of the stacked mold in the injection molding process.

[0041] In specific implementation, the control valve adopts a needle valve type hot nozzle structure. Specifically, the flow channel of the first hot runner assembly 100 is provided with a plurality of first needle valve type connecting hot nozzles 140, and the flow channel of the second hot runner assembly 200 is provided with a plurality of second needle valve type connecting hot nozzles 230. During mold closing, the first needle valve type connecting hot nozzles 140 connect to the corresponding second needle valve type connecting hot nozzles 230, so that the flow channel of the first hot runner assembly 100 is connected to the flow channel of the second hot runner assembly 200.

[0042] In this embodiment, the control valve adopts a needle valve type hot nozzle structure. Specifically, the flow channel of the first hot runner assembly 100 is provided with a plurality of first needle valve type connecting hot nozzles 140, and the flow channel of the second hot runner assembly 200 is provided with a plurality of second needle valve type connecting hot nozzles 230. The first needle valve type connecting hot nozzles 140 and the second needle valve type connecting hot nozzles 230 are arranged in a one-to-one correspondence to form a mutually cooperating connection structure.

[0043] Furthermore, both the first needle valve type connecting hot nozzle 140 and the second needle valve type connecting hot nozzle 230 include an axially movable valve needle structure, which can move between an open position (i.e., the first position) and a closed position (i.e., the second position). When the valve needle is in the open position, the flow channel of the corresponding hot nozzle is in a conductive state; when the valve needle is in the closed position, the flow channel of the corresponding hot nozzle is closed by the valve needle, thereby realizing the control of the flow of molten injection molding material.

[0044] During the mold closing process of the stacked mold, as the moving mold, middle mold, and fixed mold gradually approach and complete the mold closing, the first needle valve type connecting hot nozzle 140 and the corresponding second needle valve type connecting hot nozzle 230 are connected, making their internal flow channels interconnected. This allows the flow channels of the first hot runner assembly 100 and the second hot runner assembly 200 to form a continuous flow channel structure. In this state, the molten injection material from the first hot runner assembly 100 can enter the corresponding second needle valve type connecting hot nozzle 230 through the first needle valve type connecting hot nozzle 140, and further enter the flow channel of the second hot runner assembly 200.

[0045] Furthermore, by setting multiple corresponding first needle valve type connecting hot nozzles 140 and second needle valve type connecting hot nozzles 230, the flow channels can be connected at multiple locations, thereby ensuring the stable delivery of molten injection material in different areas and improving the material supply balance and overall operational stability of the hot runner system in the stacked mold.

[0046] In some preferred embodiments, the first needle valve type connecting hot nozzle 140 and the second needle valve type connecting hot nozzle 230 are preferably located at the connection section of the two hot runner assemblies, facilitating installation and maintenance while reducing heat loss and material retention. Structurally, the first needle valve type connecting hot nozzle 140 and the second needle valve type connecting hot nozzle 230 can be pneumatically or hydraulically driven, enabling precise movement of the needle valve under high temperature and high pressure conditions, ensuring reliable flow channel sealing, preventing material backflow or leakage, thereby improving the stability of mold injection molding and product quality. Furthermore, the first needle valve type connecting hot nozzle 140 and the second needle valve type connecting hot nozzle 230 can be arranged according to the size of the mold cavity, with multiple first needle valve type connecting hot nozzles 140 and second needle valve type connecting hot nozzles 230 evenly distributed to ensure balanced injection pressure in the cavity and avoid localized insufficient flow or short-shot phenomena.

[0047] like Figure 1As shown, in a specific implementation, the first hot runner assembly 100 includes a first manifold 110, a plurality of first needle valve injection nozzles 130, and a plurality of first needle valve connecting nozzles 140. The first manifold 110 is disposed on the fixed mold and is used to distribute the molten injection material entering the hot runner system. The first manifold 110 is provided with a feed nozzle 120. The plurality of first needle valve injection nozzles 130 are disposed on the first manifold 110, and the first needle valve injection nozzles 130 are connected to the first manifold inside the first manifold 110; the first needle valve injection nozzles 130 are connected to the gate of the first cavity. Multiple first needle valve type hot nozzles 140 are disposed on the first manifold 110, and the first needle valve type hot nozzles 140 are connected to the first manifold channel inside the first manifold 110; when the mold is closed, the first needle valve type hot nozzles 140 are connected to the flow channel of the second hot runner assembly 200.

[0048] Specifically, the first manifold 110 is provided with a hot feed nozzle 120, which is used to connect with the nozzle of the injection molding machine, thereby introducing the molten injection material injected by the injection molding machine into the interior of the first manifold 110. A first flow channel is formed inside the first manifold 110. After the molten injection material enters the first flow channel through the hot feed nozzle 120, it can be flowed and transported within the first flow channel.

[0049] Furthermore, multiple first needle valve type injection nozzles 130 are disposed on the first manifold 110 and connected to the first manifold channel inside the first manifold 110. The outlet end of the first needle valve type injection nozzle 130 is connected to the gate of the corresponding cavity, so that the molten injection material distributed by the first manifold channel can be injected into the corresponding cavity through the corresponding first needle valve type injection nozzle 130, thereby completing the mold filling process in the injection molding process.

[0050] In addition, the first manifold 110 is also provided with a plurality of first needle valve type connecting hot nozzles 140. The plurality of first needle valve type connecting hot nozzles 140 are also connected to the first manifold channel inside the first manifold 110, so that the molten injection material can enter the first needle valve type connecting hot nozzles 140 from the first manifold channel. When the stacked mold is closed, the first needle valve type connecting hot nozzles 140 can be connected to the flow channel of the second hot runner assembly 200, so that the flow channel of the first hot runner assembly 100 and the flow channel of the second hot runner assembly 200 form a connected structure, so that the molten injection material can be transported from the first hot runner assembly 100 to the second hot runner assembly 200, realizing the material supply between different layer cavities.

[0051] like Figure 3As shown, in one specific embodiment, the first diverter plate 110 is an integral structure, including a connecting part located in the middle and two diverter parts respectively disposed at both ends of the connecting part; the connecting part is generally strip-shaped and has a main flow channel inside, and the connecting part is connected to the feed nozzle 120. Each diverter part has a branch flow channel inside, and the main flow channel and the two branch flow channels together constitute the first diverter channel of the first diverter plate 110. The diverter part is generally H-shaped, including two support arms arranged at intervals between each other and a transverse connecting arm connecting the two support arms, and the end of the connecting part is connected to the transverse connecting arm of the diverter part.

[0052] Among them, a first needle valve type connecting hot nozzle 140 is correspondingly disposed on the transverse connecting arm of the flow divider and is located at the connection between the transverse connecting arm and the connecting part; multiple first needle valve type connecting hot nozzles 140 are distributed around the first needle valve type connecting hot nozzle 140 on the two support arms.

[0053] In this application, the connecting section has a main flow channel, and the branch flow section has a branch flow channel. The main flow channel and the branch flow channel together form a complete flow distribution channel, which allows the molten plastic to be evenly distributed to each branch flow channel after entering from the hot feed nozzle 120, ensuring consistent melt pressure at each cavity gate. The H-shaped flow distribution structure can effectively shorten the difference in plastic flow path, reduce the risk of melt stagnation and uneven cooling, avoid warping or surface defects in the molded parts, and improve the quality and consistency of the parts.

[0054] On the other hand, the first manifold 110 adopts an integrated structure combining a central strip-shaped connecting section with H-shaped manifold sections at both ends. This structure can significantly optimize the flow path of molten plastic in the runner. The connecting section is equipped with a main flow channel, which can be directly connected to the injection molding machine's feed nozzle 120, allowing the molten plastic to enter the branch flow channels of the manifold section quickly and evenly, avoiding stagnation or uneven temperature during flow, and improving mold filling stability and product consistency.

[0055] The combination of the two support arms and the transverse connecting arm in the H-shaped flow divider not only provides structural stability but also ensures a reasonable spatial layout of the branch flow channels, which is beneficial for achieving uniform material supply to multiple cavities within a limited mold area. The direct connection between the branch flow channels and the main flow channel allows molten plastic to be rapidly distributed from the center to the gates of each cavity, reducing flow channel pressure loss and lowering the risk of thermal degradation, thus contributing to the molding of high-quality plastic products.

[0056] In this configuration, the arrangement of the first needle valve injection nozzle 130 and the first needle valve connecting nozzle 140 has significant advantages. The first needle valve injection nozzle 130 is directly connected to the cavity gate, enabling independent control and precise filling of each cavity. The first needle valve connecting nozzle 140 is positioned on the transverse connecting arm of the manifold and close to the connecting part, which helps to shorten the flow path of the molten plastic, reduce the runner length and bending angle, thereby reducing the filling pressure requirement and flow resistance. The needle valve nozzle structure itself can quickly open and close to control the plastic flow direction. Combined with the specific structure of the manifold, it can achieve precise flow control and pressure regulation under different production process conditions, ensuring the consistency of simultaneous filling of multiple cavities and the quality of product molding.

[0057] In summary, the overall structural design of the first manifold 110 not only optimizes the flow distribution and thermal balance of molten plastic, but also achieves controllability, rationality and efficiency of multi-cavity injection molding through the reasonable arrangement of needle valve injection nozzles and connecting nozzles, providing reliable technical support for the stable operation of complex stacked molds or multi-cavity injection molds.

[0058] In this specific embodiment, both the first needle valve injection nozzle 130 and the first needle valve connecting nozzle 140 adopt a cylinder-driven needle valve nozzle structure. The needle valve nozzle structure includes a needle valve body, a needle rod, a driving cylinder, and a mounting base. The needle valve body has a needle valve hole, and the needle rod slides axially along the needle valve hole. One end of the needle rod controls the opening and closing of the needle valve hole, and the other end is connected to the cylinder piston. When the cylinder piston is pressed within the cylinder, the needle rod moves along the needle valve hole, realizing the opening and closing action of the needle valve. The driving cylinder is mounted on the outer wall of the other side of the first distributor plate 110.

[0059] The needle valve body is fixed to the first manifold 110 via a mounting base, so that the needle rod end of the needle valve is aligned with the manifold channel inside the first manifold 110. Specifically, the needle rod end of the first needle valve injection nozzle 130 is aligned with the gate of the first cavity, ensuring that molten plastic can be smoothly injected into the first cavity from the manifold channel of the first manifold 110 through the needle valve. Meanwhile, the needle rod end of the first needle valve connecting nozzle 140 can be connected to the corresponding flow channel of the second hot runner system when the mold is closed, so as to form a continuous flow channel structure.

[0060] In the specific installation structure, the needle valve body is fixed to the first flow divider plate 110 by threads or locating pins to ensure that the needle valve does not shift during injection molding. The drive cylinder is fixed to the other side surface of the first flow divider plate 110 by a threaded connection or bracket, located above the needle valve body. The piston movement of the cylinder precisely controls the opening and closing of the needle rod along the axis of the needle valve, thereby realizing the opening and closing switching of the flow channel. This cylinder-driven needle valve hot nozzle structure can withstand the long-term action of high-temperature molten plastic and provides fast, repeatable, and stable opening and closing control.

[0061] like Figure 1 As shown, the second hot runner assembly 200 includes multiple second manifolds 210, multiple second needle valve injection nozzles 220, and multiple second needle valve connecting nozzles 230. Each second manifold 210 corresponds to one first needle valve connecting nozzle 140. The second needle valve injection nozzle 220 is disposed on the second manifold 210 and is connected to the second manifold inside the second manifold 210; the second needle valve injection nozzle 220 is connected to the gate of the second cavity. The second needle valve connecting nozzle 230 is disposed on the second manifold 210 and is connected to the second manifold inside the second manifold 210; during mold closing, the second needle valve connecting nozzle 230 connects to the flow channel of the first hot runner assembly 100.

[0062] In one specific embodiment, the second hot runner assembly 200 includes multiple second manifolds 210, multiple second needle valve injection nozzles 220, and multiple second needle valve connecting nozzles 230. Each second manifold 210 is correspondingly provided with a first needle valve connecting nozzle 140 to achieve a corresponding connection between the first hot runner assembly 100 and the second hot runner assembly 200. Each second manifold 210 has a second manifold inside, and the second needle valve injection nozzle 220 is disposed on the second manifold 210 and communicates with the second manifold, for uniformly conveying molten injection material from the second manifold 210 to the gate of the second cavity. During the injection molding process, the second needle valve injection nozzle 220 can control the time and flow rate of molten material flowing into the second cavity, thereby ensuring the injection uniformity of the second cavity and reducing defects such as porosity, flash, and weld lines.

[0063] Specifically, the second needle valve type connecting hot nozzle 230 is disposed on the second manifold plate 210 and communicates with the second manifold channel. In the mold closed state, the second needle valve type connecting hot nozzle 230 corresponds to the flow channel of the first hot runner assembly 100, allowing the molten injection material of the first hot runner assembly 100 to smoothly enter the second hot runner assembly 200, forming a continuous flow channel structure. The principle of this connection method is that, through the mechanical cooperation of the needle valve type connecting hot nozzle, the two sets of hot runner assemblies achieve rapid sealing and communication when the mold is closed, and automatically disconnect when the mold is opened, thereby preventing molten material backflow or leakage.

[0064] Through the above structural design, the second hot runner assembly 200 not only ensures stable injection molding in the second cavity, but also, through its connection with the first hot runner assembly 100, achieves continuous and efficient delivery of molten material in the multi-cavity injection molding system. This implementation improves injection accuracy, shortens injection cycle time, reduces material waste, and simultaneously ensures the reliability and repeatability of the hot runner system during mold closing and opening processes.

[0065] like Figure 1As shown, the second manifold 210 has an overall H-shaped structure, including two support arms spaced apart from each other and a transverse connecting arm connecting the two support arms. A second needle valve type connecting hot nozzle 230 is correspondingly disposed on the transverse connecting arm of the second manifold 210, and multiple second needle valve type injection hot nozzles 220 are distributed around the second needle valve type connecting hot nozzle 230 on the two support arms of the second manifold 210.

[0066] In some specific embodiments of this application, the second manifold 210 has an overall H-shaped structure, including two spaced-apart support arms and a transverse connecting arm connecting the two support arms. This structural design allows the second manifold 210 to rationally arrange the flow channels and hot nozzles while ensuring structural strength and rigidity, ensuring uniform distribution and stable flow of molten plastic within the manifold. The support arms provide spatial support for the flow channel layout.

[0067] A second needle valve type connecting hot nozzle 230 is correspondingly set on the transverse connecting arm, located at the center of the H-shaped structure. Multiple second needle valve type connecting hot nozzles 230 are distributed around the central connecting hot nozzle on the two support arms. This layout can shorten the path of molten plastic from the center of the manifold to each cavity, reduce flow resistance and pressure loss, and ensure the balance of filling speed and pressure.

[0068] With this H-shaped manifold structure, the arrangement of the second needle valve injection nozzle 220 and the connecting nozzle enables precise flow control during multi-cavity or stacked mold injection. The needle valve nozzle structure can be quickly opened and closed by a cylinder to control the plastic flow direction. Combined with the support arm and lateral connecting arm of the H-shaped manifold, it allows for flexible switching of flow channels, optimization of mold filling sequence, and reduction of melt residence time in multi-cavity injection molding, which is beneficial to improving product molding quality and consistency.

[0069] In some specific embodiments of this application, the first manifold 110 and the second manifold 210 form a continuous flow channel structure through needle valve-type connecting hot nozzles. The combined design of the two exhibits significant synergistic advantages in multi-cavity and stacked injection molding. The first manifold 110 adopts a strip-shaped and H-shaped combined structure with a central connecting part and two end manifolds. The connecting part has a main flow channel, and the manifolds have branch flow channels, forming a uniform first manifold. The second manifold 210 has an overall H-shaped structure. The transverse connecting arm carries the central needle valve-type connecting hot nozzle, and multiple needle valve-type connecting hot nozzles are evenly distributed on the two support arms, forming the second manifold.

[0070] Through the above structural combination, the first manifold 110 and the second manifold 210 can achieve efficient connection and uniform distribution of molten plastic across the manifold channels. The main channel and branch channels of the first manifold 110 uniformly guide the melt to the central connecting nozzle of the second manifold 210, and then multiple injection nozzles arranged by the support arms of the second manifold 210 further distribute the melt to each cavity. This combination shortens the melt flow path, reduces pressure loss, and ensures the filling speed and pressure balance of each cavity, thereby improving the molding quality and consistency of the injection molded products.

[0071] In one specific embodiment, in order to meet the injection material supply requirements of the first cavity and the second cavity in the stacked mold, the installation direction of various hot nozzles is set accordingly.

[0072] Specifically, the first needle valve type injection hot nozzle 130 and the first needle valve type connecting hot nozzle 140, which are disposed on the first manifold plate 110, have the same orientation. The first needle valve type injection hot nozzle 130 is positioned towards the gate direction of the first cavity to inject molten injection material into the first cavity; while the first needle valve type connecting hot nozzle 140 is positioned towards the intermediate mold direction to connect with the second hot runner assembly 200 when the mold is closed, thereby realizing the flow channel connection.

[0073] Accordingly, in the second hot runner assembly 200, the second needle valve injection nozzle 220 and the second needle valve connecting nozzle 230 are oriented in opposite directions. The second needle valve injection nozzle 220 is positioned towards the gate direction of the second cavity to deliver molten injection material into the second cavity; while the second needle valve connecting nozzle 230 is positioned towards the fixed mold direction to correspond to the first needle valve connecting nozzle 140 of the first hot runner assembly 100 when the mold is closed.

[0074] Furthermore, the first needle valve type connecting hot nozzle 140 and the second needle valve type connecting hot nozzle 230 are oriented opposite to each other. When the stacked mold is closed, the two can be connected to each other in the axial direction, so that the flow channel of the first hot runner assembly 100 and the flow channel of the second hot runner assembly 200 form a connected structure, so that the molten injection material can be transferred between the two hot runner assemblies to meet the injection molding requirements of the multi-layer cavity of the stacked mold.

[0075] like Figure 4 As shown in the embodiment of this application, a stacked mold is also provided, which includes the hot runner system described above.

[0076] In one specific embodiment, this application also provides a stacked mold, which includes a moving mold 10, a middle mold 20, and a fixed mold 30, and the aforementioned hot runner system is arranged between the middle mold and the fixed mold, and between the moving mold and the middle mold. Specifically, the moving mold and the middle mold form a first cavity when the mold is closed, and the middle mold and the fixed mold form a second cavity when the mold is closed; a first hot runner assembly is disposed in the fixed mold, and a second hot runner assembly is disposed in the middle mold.

[0077] The working principle of this stacked mold is as follows: When the mold is closed, the flow channel of the first hot runner assembly is connected to the flow channel of the second hot runner assembly through a needle valve-type connecting hot nozzle, forming a continuous molten injection material delivery path. The molten material is injected from the first manifold through the first needle valve-type injection hot nozzle into the first cavity, and simultaneously enters the second hot runner assembly through the first needle valve-type connecting hot nozzle, and is then injected into the second cavity through the second needle valve-type injection hot nozzle. This structure ensures that the two cavities can be injected synchronously or in a preset sequence, and can effectively control the flow direction, flow rate, and pouring time of the injection material.

[0078] Specifically, a stacked mold includes a moving mold, a middle mold, and a fixed mold that are stacked sequentially and can open and close relative to each other.

[0079] The moving mold includes a first mold core, the middle mold includes a second mold core and a third mold core, and the fixed mold includes a fourth mold core; the first mold core and the second mold core together form a first cavity for injection molding when the mold is closed; the third mold core and the fourth mold core together form a second cavity for injection molding when the mold is closed.

[0080] The fixed mold is provided with a first hot runner assembly, the runner of the first hot runner assembly is connected to the gate of the second cavity; the first hot runner assembly has a feed nozzle that is connected to an external injection molding machine.

[0081] The middle mold is equipped with a second hot runner assembly, and the runner of the second hot runner assembly is connected to the gate of the first cavity.

[0082] During mold closing, the runner of the first hot runner assembly is connected to the runner of the second hot runner assembly to form a continuous runner structure, and the molten injection material enters the runner of the second hot runner assembly through the runner of the first hot runner assembly.

[0083] In one specific embodiment, the stacked mold includes a moving mold, a middle mold, and a fixed mold stacked sequentially. The moving mold, the middle mold, and the fixed mold can perform relative opening and closing movements to complete the injection molding cycle.

[0084] Specifically, the moving mold includes a first mold core, the middle mold includes a second mold core and a third mold core, and the fixed mold includes a fourth mold core. When the mold is closed, the first and second mold cores cooperate and enclose each other to form a first cavity for injection molding; the third and fourth mold cores cooperate and enclose each other to form a second cavity for injection molding, thus enabling the stacked mold to form multiple cavities at different levels for injection molding.

[0085] Furthermore, a first hot runner assembly is provided on the fixed mold. The runner of the first hot runner assembly is connected to the gate of the second cavity for supplying molten injection molding material into the second cavity. The first hot runner assembly is also provided with a hot inlet nozzle for connecting to the nozzle of an external injection molding machine to introduce molten injection molding material supplied by the injection molding machine into the runner of the first hot runner assembly. A second hot runner assembly is provided on the intermediate mold. The runner of the second hot runner assembly is connected to the gate of the first cavity for supplying molten injection molding material into the first cavity.

[0086] When a stacked mold is closed, the runner of the first hot runner assembly can connect with the runner of the second hot runner assembly, forming a continuous runner structure. This allows molten injection material, fed from an external injection molding machine through a hot nozzle, to first enter the runner of the first hot runner assembly and then further into the runner of the second hot runner assembly, thus supplying material to different cavities. This structural design enables multi-cavity material delivery and injection molding in a stacked mold, improving molding efficiency and production stability.

[0087] Furthermore, during the mold opening process, the moving mold, middle mold, and fixed mold can undergo relative separation movements in a preset sequence. For example, after injection molding is completed and cooled, the moving mold first separates relative to the middle mold, opening the first cavity and completing the demolding of the corresponding product; subsequently, the middle mold separates relative to the fixed mold, opening the second cavity, thereby achieving the demolding of another layer of product. By rationally designing the mold opening sequence, interference between different cavities can be avoided, and it is beneficial to achieve smooth ejection of the product.

[0088] In terms of injection molding material supply, the first hot runner assembly is located in the fixed mold and connected to an external injection molding machine via a hot nozzle, allowing the molten injection material to first enter the runner inside the first hot runner assembly. The first hot runner assembly can directly supply molten injection material to the second cavity. Furthermore, when the mold is closed, its runner can connect with the runner of the second hot runner assembly located in the intermediate mold, forming a continuous supply channel. This allows the molten injection material to further enter the second hot runner assembly and ultimately be delivered to the gate of the first cavity.

[0089] The aforementioned flow channel connection structure enables a single injection molding machine to supply material to multiple cavities, allowing two cavities to complete the mold filling process within the same injection cycle. Furthermore, by incorporating needle valves in each hot runner, the feeding status of different cavities can be controlled according to actual production needs, such as sequential feeding, synchronous feeding, or partial shut-off, thereby improving the stability of the injection molding process and the quality of the molded product.

[0090] Furthermore, since the intermediate mold simultaneously supports the structure of two cavities and arranges the hot runners, its internal space utilization is relatively high. Therefore, by adopting a manifold structure and modularizing the second hot runner assembly, the complexity of the intermediate mold's internal structure can be effectively reduced, facilitating mold installation, maintenance, and replacement. Combined with the manifold design of the first hot runner assembly, this also allows for a balanced distribution of molten injection material among multiple cavities, thereby reducing problems such as uneven filling and excessive pressure loss.

[0091] Based on the above embodiments, in addition to enclosing and forming the cavity and arranging the hot runner components, the moving mold, the middle mold and the fixed mold can also be set with a variety of functional structures according to the actual needs of injection molding to realize functions such as mold guiding, mold locking and positioning, cooling and product ejection.

[0092] Firstly, regarding structural support and guidance, guiding mechanisms can be provided between the moving mold, the intermediate mold, and the fixed mold. For example, guide pillars and guide sleeves can be provided between the fixed mold and the intermediate mold, and between the intermediate mold and the moving mold, respectively, to guide and position each mold body during mold closing and opening, ensuring accurate alignment between the mold cores, thereby ensuring the sealing and molding accuracy of the first and second cavities during mold closing. Simultaneously, positioning blocks or conical positioning structures can be provided at the mold mating surfaces to further improve the positioning accuracy of the mold during mold closing and reduce the impact of misalignment on product quality.

[0093] Secondly, regarding temperature control, cooling channels can be separately installed inside the moving mold, intermediate mold, and fixed mold to introduce cooling media and regulate mold temperature. By arranging cooling water channels around the first, second, third, and fourth mold cores, the cavity areas can dissipate heat rapidly after injection molding, thereby shortening the cooling time of the product and improving injection molding efficiency. Simultaneously, considering the relatively large thickness of the intermediate mold in the stacked structure, multi-layered or surrounding cooling channels can be installed inside the intermediate mold to improve heat exchange efficiency and ensure uniform temperature distribution in each cavity area.

[0094] Furthermore, regarding product demolding, an ejection mechanism is typically provided on the moving mold side. Specifically, the moving mold may contain structures such as an ejector plate, ejector pins, and a reset mechanism, with the front end of the ejector pin corresponding to the product in the first cavity. After mold opening, the ejector plate, driven by the ejection mechanism of the injection molding machine, moves the ejector pins forward, thereby ejecting the product from the surface of the first mold core. After ejection, the ejector plate returns to its initial position under the action of the reset mechanism, ready for the next injection cycle.

[0095] For the second cavity forming area, a corresponding demolding mechanism can also be set on one side of the middle mold or the fixed mold. For example, an ejector assembly or push block structure can be set inside the middle mold so that the product in the second cavity can be smoothly ejected after the middle mold and the fixed mold are separated, thereby realizing the sequential demolding of the double-cavity product. In addition, the molding requirements of products with lateral structures or undercut structures can be met by setting inclined ejectors, sliders, or side core-pulling mechanisms.

[0096] In addition, regarding structural strength and installation, the moving mold, middle mold, and fixed mold typically include mold base plates, support plates, and fixing plates to mount the mold core and hot runner components, and to withstand the clamping force and injection pressure generated during injection molding. By setting support columns or reinforcing structures inside the mold base, the overall rigidity of the mold can be improved, reducing deformation caused by stress during injection molding, thereby ensuring the stability of the cavity dimensions and the quality of the product.

[0097] Through the above structural setup, the moving mold, middle mold, and fixed mold can not only work together to form a multi-layer cavity structure, but also play a role in guiding and positioning, temperature control, product demolding, and structural support, so that the stacked mold has good stability, reliability and production efficiency in the injection molding process.

[0098] In a preferred embodiment, the intermediate mold is connected to a load-bearing structure configured to fix the intermediate mold to the frame or moving mechanism of the injection molding machine; the load-bearing structure includes a support plate, two bases, and two fixing blocks; the support plate is used to connect to the frame or moving mechanism of the injection molding machine; the two bases are connected to the support plate, and the two bases are respectively spaced apart on both sides of the surface of the support plate; the bases are connected to adjusting pads; the two fixing blocks are respectively connected to the two bases, and the fixing blocks are bolted to the intermediate mold.

[0099] In a preferred embodiment, the intermediate mold is connected to a load-bearing structure configured to fix the intermediate mold to the frame or moving mechanism of the injection molding machine to support and position the intermediate mold, thereby ensuring the stability of the stacked mold during the mold opening and closing process.

[0100] Specifically, the load-bearing structure includes a support plate, two bases, and two fixing blocks. The support plate is used to connect to the frame or moving mechanism of the injection molding machine, thus serving as the basic mounting component of the entire load-bearing structure, supporting the weight of the intermediate mold and transferring the load to the injection molding machine structure. The two bases are connected to the support plate and are spaced apart on both sides of the support plate surface to form a support structure for both sides of the intermediate mold. By distributing the bases on both sides of the support plate, the overall stability of the support structure is improved, and the load generated by the intermediate mold during operation is more evenly distributed.

[0101] Furthermore, each base is equipped with an adjusting shim. The adjusting shim is used to fine-tune the installation height or horizontal position of the middle mold to compensate for installation errors or equipment assembly tolerances, thereby ensuring that the middle mold, moving mold, and fixed mold maintain a good alignment when the mold is closed, and improving the fitting accuracy of the mold.

[0102] In addition, the two fixing blocks are respectively connected to the two bases and fixed to the intermediate mold via bolts. The bolted connection between the fixing blocks and the intermediate mold reliably secures the intermediate mold to the load-bearing structure, preventing displacement due to stress during injection molding. This structure also facilitates mold installation and disassembly; when mold maintenance or replacement is required, the intermediate mold can be quickly disassembled by removing the bolts.

[0103] By setting up the above-mentioned load-bearing structure, the weight of the middle mold can be effectively supported and the installation stability of the stacked mold on the injection molding machine can be improved. At the same time, it is beneficial to improve the stress state of the mold, reduce the vibration or displacement of the mold during operation, thereby improving the stability of the injection molding process and the quality of the product.

[0104] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. For those skilled in the art, it will be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A hot runner system for a stacked mold having a moving mold, a middle mold, and a fixed mold, wherein the moving mold and the middle mold close together to form a first cavity, and the middle mold and the fixed mold close together to form a second cavity, characterized in that, The hot runner system includes: A first hot runner assembly is disposed in a fixed mold, and the runner of the first hot runner assembly is connected to the gate of the second cavity. The second hot runner assembly is disposed in the middle mold, and the runner of the second hot runner assembly is connected to the gate of the first cavity; In the case of the moving mold, middle mold and fixed mold of the stacked mold being closed, the flow channel of the first hot runner assembly is connected to the flow channel of the second hot runner assembly to form a continuous flow channel structure, and the molten injection material enters the flow channel of the second hot runner assembly through the flow channel of the first hot runner assembly.

2. A hot runner system according to claim 1, characterized in that: The flow channels of the first hot runner assembly and the second hot runner assembly are respectively provided with control valves, and the control valves can switch between a first position and a second position; When the control valve is in the first position, it connects the flow channel of the first hot runner assembly with the flow channel of the second hot runner assembly; when the control valve is in the second position, it blocks the connection between the flow channel of the first hot runner assembly and the flow channel of the second hot runner assembly.

3. A hot runner system according to claim 2, characterized in that: The control valve adopts a needle valve type hot nozzle structure. Specifically, the flow channel of the first hot runner assembly is provided with a plurality of first needle valve type connecting hot nozzles, and the flow channel of the second hot runner assembly is provided with a plurality of second needle valve type connecting hot nozzles. During mold closing, the first needle valve type connecting hot nozzle connects to the corresponding second needle valve type connecting hot nozzle, so that the flow channel of the first hot runner assembly is connected to the flow channel of the second hot runner assembly.

4. A hot runner system according to any one of claims 1 to 3, characterized in that, The first hot runner assembly includes: A first manifold plate is disposed on the fixed mold, and the first manifold plate is provided with a feeding hot nozzle; Multiple first needle valve type injection hot nozzles are disposed on the first manifold, and the first needle valve type injection hot nozzles are connected to the first manifold channel inside the first manifold; the first needle valve type injection hot nozzles are connected to the gate of the first cavity. Multiple first needle valve type hot nozzles are disposed on the first manifold, and the first needle valve type hot nozzles are connected to the first manifold channel inside the first manifold; when the mold is closed, the first needle valve type hot nozzles are connected to the flow channel of the second hot runner assembly.

5. A hot runner system according to claim 4, characterized in that: The first diverter plate is an integral structure, which includes a connecting part located in the middle and two diverter parts respectively disposed at both ends of the connecting part; the connecting part is generally strip-shaped and has a main channel inside, and the connecting part is connected to the feed nozzle; Each branch section has a branch flow channel inside, and the main flow channel and the two branch flow channels together form the first branch flow channel of the first branch plate; The diversion section has an overall H-shaped structure, including two support arms spaced apart from each other and a transverse connecting arm connecting the two support arms. The end of the connecting section is connected to the transverse connecting arm of the diversion section. One of the first needle valve type connecting hot nozzles is correspondingly set on the transverse connecting arm of the flow divider and is located at the connection between the transverse connecting arm and the connecting part; multiple first needle valve type connecting hot nozzles are distributed around the first needle valve type connecting hot nozzle on the two support arms.

6. A hot runner system according to claim 4, characterized in that: The second hot runner assembly includes multiple second manifolds, multiple second needle valve injection nozzles, and multiple second needle valve connecting nozzles, with one second manifold corresponding to one first needle valve connecting nozzle. The second needle valve injection hot nozzle is disposed on the second manifold, and the second needle valve injection hot nozzle is connected to the second manifold channel inside the second manifold; the second needle valve injection hot nozzle is connected to the gate of the second cavity; The second needle valve type hot nozzle is disposed on the second manifold, and the second needle valve type hot nozzle is connected to the second manifold channel inside the second manifold; when the mold is closed, the second needle valve type hot nozzle is connected to the flow channel of the first hot runner assembly.

7. A hot runner system according to claim 6, characterized in that: The second diverter plate has an overall H-shaped structure, including two support arms spaced apart from each other and a transverse connecting arm connecting the two support arms; A second needle valve type connecting hot nozzle is correspondingly set on the transverse connecting arm of the second manifold, and multiple second needle valve type injection hot nozzles are distributed around the second needle valve type connecting hot nozzle on the two support arms of the second manifold.

8. A stacking mold, characterized in that, The stacked mold includes the hot runner system as described in any one of claims 1 to 7.

9. The stacked mold according to claim 8, characterized in that: This includes a moving mold, a middle mold, and a fixed mold that are stacked sequentially and can open and close relative to each other; The intermediate mold is connected to a load-bearing structure, which is configured to fix the intermediate mold to the frame or moving mechanism of the injection molding machine. The load-bearing structure includes a support plate, two bases, and two fixing blocks; the support plate is used to connect the frame or moving mechanism of the injection molding machine; the two bases are connected to the support plate, and the two bases are respectively spaced apart on both sides of the surface of the support plate; the bases are connected to adjusting pads; the two fixing blocks are respectively connected to the two bases, and the fixing blocks are bolted to the intermediate mold.

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