Hot runner injection cavity mold

Abstract

The utility model discloses a hot runner injection cavity mould, including forming subassembly and injection assembly, forming subassembly includes injection mould, and the injection cavity is formed in injection mould, and the injection cavity has the gate, injection assembly includes hot nozzle, valve needle body, heat insulating sheet and valve needle seal glue ring, the runner cavity is formed in hot nozzle, and the runner cavity has runner outlet, and the runner outlet sets up close to the gate, and the valve needle body is movably worn in the runner cavity to control the opening and close of runner outlet, the valve needle body has valve needle head end, and valve needle head end can be by runner outlet and extend, and valve needle head end has first seal glue surface, valve needle seal glue ring sets up in one side of hot nozzle, and valve needle seal glue ring has seal glue passage in, and seal glue passage intercommunication gate and runner outlet, and the inner wall of seal glue passage forms second seal glue surface, first seal glue surface and second seal glue surface are adapted, and heat insulating sheet sets up between valve needle seal glue ring and hot nozzle, the utility model can reduce the temperature of valve needle head, promote the cooling of product glue mouth, avoid the gate and turn white, and draw silk.

Description

Technical Field

[0001] This utility model relates to the field of injection mold technology, specifically to a hot runner injection cavity mold. Background Technology

[0002] Hot runner injection molds are an advanced type of injection mold that incorporates a heating device inside the mold. This keeps the plastic molten throughout the entire runner from the injection machine nozzle to the mold cavity, preventing it from cooling and solidifying with the finished product.

[0003] In current hot runner injection molds, because the valve needle head is in direct contact with the gate, the excessive temperature of the valve needle head causes the temperature of the gate area in the mold cavity to rise. The high shear heat when the raw material is injected into the mold cavity leads to whitening and stringing at the gate area of ​​the product. Utility Model Content

[0004] In order to overcome the shortcomings of the existing technology, the purpose of this utility model is to provide a hot runner injection mold that can reduce the temperature of the valve needle head, promote the cooling of the product gate, and prevent the gate from turning white and stringing.

[0005] The objective of this utility model is achieved through the following technical solution: A hot runner injection mold, characterized in that it includes a molding component and an injection component; The molding component includes an injection mold, in which an injection cavity is formed, and the injection cavity has a gate; The injection molding assembly includes a hot nozzle, a valve needle body, a heat insulation sheet, and a valve needle sealing ring. A flow channel cavity is formed within the hot nozzle, and the flow channel cavity has a flow channel outlet located near the gate. The valve needle body is movably inserted into the flow channel cavity to control the opening and closing of the flow channel outlet. The valve needle body has a valve needle tip that can extend from the flow channel outlet and has a first sealing surface. The valve needle sealing ring is located on one side of the hot nozzle and has a sealing channel that connects the gate and the flow channel outlet. A second sealing surface is formed on the inner wall of the sealing channel. The first sealing surface and the second sealing surface are adapted to each other. The heat insulation sheet is located between the valve needle sealing ring and the hot nozzle.

[0006] In one optional embodiment, the injection molding assembly further includes a heating device, the heating device including a heating sleeve, and a plurality of heating wires disposed inside the heating sleeve; the heating sleeve is disposed circumferentially to the hot nozzle.

[0007] In one optional embodiment, the injection molding assembly further includes a driving device, which is connected to the valve needle body for transmission. The driving device drives the valve needle body to translate, so that the first sealing surface and the second sealing surface move closer or further apart, thereby controlling the opening or closing of the sealing channel and realizing the opening and closing of the flow channel outlet.

[0008] In one optional embodiment, the first sealing surface is an outer conical surface; the second sealing surface is an inner conical surface.

[0009] In one optional embodiment, the injection mold has a mating groove, and an installation groove is provided in the mating groove, the installation groove being connected to the gate.

[0010] In one optional embodiment, the hot nozzle is disposed in the mating groove, and the surface of the hot nozzle forms a heat-insulating gap with the inner wall of the mating groove.

[0011] In one optional embodiment, the valve needle sealing ring is detachably connected to the mounting groove.

[0012] In one optional embodiment, the heat insulation sheet is fitted into the mounting groove and pressed between the valve needle sealing ring and the hot nozzle; a passage is formed in the heat insulation sheet, and the passage connects the sealing channel and the flow channel outlet; the passage is adapted to the valve needle body.

[0013] In one alternative embodiment, the valve needle sealing ring is made of a hardened, wear-resistant material.

[0014] In one optional embodiment, the system further includes a mounting bracket on which an injection molding station is formed; the molding component is fixed to the top of the injection molding station, and the injection molding component is fixed to the bottom of the injection molding station.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model of a hot runner injection mold, by driving the valve needle body to move, causes its hardened valve needle tip to pass sequentially through the runner outlet and the heat insulation plate before being pressed into the sealing channel of the valve needle sealing ring. At this time, the first sealing surface and the second sealing surface are tightly attached, cutting off the path of molten material from the runner cavity into the injection cavity. This physical cutting ensures that there are no residual melt threads, and even if the plastic has a high viscosity, it cannot be pulled out, effectively avoiding the "stringing" phenomenon. By placing the heat insulation plate between the valve needle sealing ring and the hot nozzle, heat conduction between the valve needle sealing ring and the hot nozzle is blocked. When the valve needle tip is in close contact with the valve needle sealing ring, heat is quickly carried away through metal-to-metal contact conduction, effectively preventing the valve needle tip temperature from becoming too high and causing the temperature of the mold cavity gate to rise locally. This promotes the cooling of the product gate, reduces the slow solidification process of the plastic under shear, thereby reducing internal stress and avoiding the "whitening" phenomenon caused by stress concentration, resulting in smoother gate marks and higher quality products. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the hot runner injection mold of Example 1; Figure 2 This is a partial enlarged view of part A of the hot runner injection mold in Example 1.

[0017] In the diagram: 10. Molding component; 11. Injection mold; 111. Injection cavity; 112. Gate; 113. Insulation gap; 20. Injection component; 21. Hot nozzle; 211. Runner cavity; 212. Runner outlet; 22. Valve needle body; 221. Valve needle head; 23. Insulation sheet; 231. Passage port; 24. Valve needle sealing ring; 241. Sealing channel; 25. Heating device; 30. Mounting bracket. Detailed Implementation

[0018] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments. Unless otherwise specified, the materials and equipment used in this embodiment are all commercially available. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0019] In the description of this application, it should be understood that the terms "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In the description of this application, "a plurality of" means two or more, unless otherwise precisely specified.

[0020] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected," "linked," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a connection through an intermediary, or a connection within two elements or an interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0021] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product, or apparatus.

[0022] Example 1: Please refer to Figure 1-2 This embodiment provides a hot runner injection mold, including a molding component 10 and an injection molding component 20.

[0023] The molding component 10 includes an injection mold 11, in which an injection cavity 111 is formed. The injection cavity 111 has a gate 112, which is located at the bottom of the injection cavity 111. The gate 112 is inverted conical and serves as a channel for molten plastic to enter the injection cavity 111.

[0024] Injection assembly 20 includes a hot nozzle 21, a valve needle body 22, a heat insulation sheet 23, and a valve needle sealing ring 24. A flow channel cavity 211 is formed inside the hot nozzle 21, and the flow channel cavity 211 has a flow channel outlet 212, which is located near the gate 112. A valve needle body 22 is movably inserted into the flow channel cavity 211 to control the opening and closing of the flow channel outlet 212. The valve needle body 22 has a valve needle tip 221, which can extend out of the flow channel outlet 212. A first sealing surface is formed on the outer periphery of the valve needle tip 221. A valve needle sealing ring 24 is disposed on one side of the hot nozzle 21, and a sealing channel 241 is provided inside the valve needle sealing ring 24. The sealing channel 241 connects the gate 112 and the flow channel outlet 212. A second sealing surface is formed on the inner wall of the sealing channel 241. The first sealing surface and the second sealing surface are adapted to each other. A heat insulation sheet 23 is disposed between the valve needle sealing ring 24 and the hot nozzle 21.

[0025] Based on the above structure, in this embodiment, the hot runner injection mold moves upward under hydraulic or pneumatic drive via the valve needle body 22. The hard valve needle tip 221 passes through the runner outlet 212 and the heat insulation sheet 23 in sequence and is pressed into the sealing channel 241 of the valve needle sealing ring 24. At this time, the first sealing surface and the second sealing surface are tightly attached, cutting off the path of the molten material from the runner cavity 211 into the injection cavity 111. The physical cutting ensures that there are no residual melt strands. Even if the plastic viscosity is high, it cannot be pulled out, avoiding the "stringing" phenomenon. The heat insulation sheet 23 is disposed between the valve needle sealing ring 24 and the hot nozzle 21 to block the heat conduction between the valve needle sealing ring 24 and the hot nozzle 21. When the valve needle tip 221 is in close contact with the valve needle sealing ring 24, heat is quickly carried away through metal-to-metal contact conduction, preventing the temperature of the valve needle tip from rising too high and causing the temperature of the mold cavity gate 112 to rise locally. It can promote the cooling of the product gate, reduce the slow solidification process of plastic under shear, thereby reducing internal stress and avoiding the "whitening" phenomenon caused by stress concentration, making the product gate marks smoother and of higher quality.

[0026] Specifically, the injection molding assembly 20 also includes a heating device 25, which includes a heating sleeve and a plurality of heating wires inside the heating sleeve. The heating sleeve is disposed around the hot nozzle 21, and the material inside the flow channel cavity 211 is uniformly heated by the heating device 25.

[0027] The injection molding assembly 20 also includes a driving device, which is connected to the valve needle body 22. The driving device includes, but is not limited to, hydraulic, pneumatic or mechanical drive. The driving device drives the valve needle body 22 to move, so that the first sealing surface and the second sealing surface move closer or further apart, thereby controlling the opening or closing of the sealing channel 241 and realizing the opening and closing of the flow channel outlet 212.

[0028] Furthermore, in this embodiment, the first sealing surface is an outer conical surface, and the second sealing surface is an inner conical surface. Through the tight fit between the inner and outer conical surfaces, the material flow is physically cut off, achieving zero leakage.

[0029] The hot runner injection mold of this embodiment also includes a mounting bracket 30, on which an injection station is formed; the molding component 10 is fixed to the top of the injection station, and the injection component 20 is fixed to the bottom of the injection station. The mounting bracket 30 provides a mounting base for the molding component 10 and the injection component 20, and enables them to be smoothly aligned and connected.

[0030] The injection mold 11 has a mating groove at its bottom, and an installation groove is provided on the top of the inner wall of the mating groove. The installation groove is correspondingly provided with the gate 112 and is connected to the gate 112. A hot nozzle 21 is provided in the mating groove, and the surface of the hot nozzle 21 forms a heat insulation gap 113 with the inner wall of the mating groove to reduce the contact area and reduce heat conduction.

[0031] The valve needle sealing ring 24 is detachably connected to the mounting groove. The valve needle sealing ring 24 can be detachably connected to the mounting groove by means of threaded connection or fastener connection. The detachable and independently set valve needle sealing ring 24 can be easily replaced, thereby improving the service life of the hot runner injection mold.

[0032] The heat insulation sheet 23 is fitted into the mounting groove and pressed between the valve needle sealing ring 24 and the hot nozzle 21. A passage 231 is formed in the heat insulation sheet 23, which connects the sealing channel 241 and the flow outlet 212. The passage 231 is adapted to the valve needle body 22. In this way, the heat insulation sheet 23 is stably connected between the valve needle body 22 and the hot nozzle 21, providing a better heat insulation effect.

[0033] Injection mold 11 typically uses mold steels such as S136 and NAK80, emphasizing comprehensive polishability and toughness. In this embodiment, the valve needle sealing ring 24 is made of a special material with higher hardness and wear resistance, such as tungsten steel or powder high-speed steel, which has extremely high hardness and wear resistance. After special heat treatment, it achieves extremely high hardness, ensuring the performance of key friction pairs, thereby increasing the service life of the entire hot runner injection mold system by several times or even tens of times.

[0034] Although certain components and embodiments of this application have been illustrated and described, many modifications and alterations (e.g., variations in the size, dimensions, structure, shape and proportion of the various elements, installation arrangement, material use, color, orientation, etc.) will be conceived by those skilled in the art without actually departing from the scope and spirit of the claims.

[0035] Finally, it should be noted that the above embodiments are only preferred embodiments of this utility model and should not be used to limit the scope of protection of this utility model. Any non-substantial changes and substitutions made by those skilled in the art based on this utility model shall fall within the scope of protection claimed by this utility model.

Claims

1. A hot runner injection mold, characterized in that, Including molded components and injection molded components; The molding component includes an injection mold, in which an injection cavity is formed, and the injection cavity has a gate; The injection molding assembly includes a hot nozzle, a valve needle body, a heat insulation sheet, and a valve needle sealing ring. A flow channel cavity is formed within the hot nozzle, and the flow channel cavity has a flow channel outlet located near the gate. The valve needle body is movably inserted into the flow channel cavity to control the opening and closing of the flow channel outlet. The valve needle body has a valve needle tip that can extend from the flow channel outlet and has a first sealing surface. The valve needle sealing ring is located on one side of the hot nozzle and has a sealing channel that connects the gate and the flow channel outlet. A second sealing surface is formed on the inner wall of the sealing channel. The first sealing surface and the second sealing surface are adapted to each other. The heat insulation sheet is located between the valve needle sealing ring and the hot nozzle.

2. A hot runner injection mold according to claim 1, characterized in that, The injection molding assembly also includes a heating device, which includes a heating sleeve with a plurality of heating wires disposed inside the heating sleeve; the heating sleeve is disposed circumferentially to the hot nozzle.

3. A hot runner injection mold according to claim 1, characterized in that, The injection molding assembly also includes a driving device, which is connected to the valve needle body. The driving device drives the valve needle body to move horizontally, so that the first sealing surface and the second sealing surface move closer or further apart, thereby controlling the opening or closing of the sealing channel and realizing the opening and closing of the flow channel outlet.

4. A hot runner injection mold according to claim 1, characterized in that, The first sealing surface is an outer conical surface; the second sealing surface is an inner conical surface.

5. A hot runner injection mold according to claim 1, characterized in that, The injection mold has a mating groove, and an installation groove is provided in the mating groove, which is connected to the gate.

6. A hot runner injection mold according to claim 5, characterized in that, The hot nozzle is disposed in the docking groove, and the surface of the hot nozzle forms a heat insulation gap with the inner wall of the docking groove.

7. A hot runner injection mold according to claim 5, characterized in that, The valve needle sealing ring is detachably connected to the mounting groove.

8. A hot runner injection mold according to claim 7, characterized in that, The heat insulation sheet is fitted into the mounting groove and pressed between the valve needle sealing ring and the hot nozzle; a passage is formed in the heat insulation sheet, which connects the sealing channel and the flow channel outlet; the passage is adapted to the valve needle body.

9. A hot runner injection mold according to claim 7, characterized in that, The valve needle sealing ring is made of hardened wear-resistant material.

10. A hot runner injection mold according to claim 1, characterized in that, It also includes a mounting frame on which an injection molding station is formed; the molding component is fixed to the top of the injection molding station and the injection molding component is fixed to the bottom of the injection molding station.

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