A main sprue nozzle structure for injection mold

Abstract

The utility model relates to hot runner technology field and disclose a main nozzle structure for injection mold, including nozzle body, middle part insert and head insert, the inside of nozzle body is provided with first runner, the inside of middle part insert is provided with the second runner of first runner intercommunication, the inside of head insert is provided with the third runner of second runner intercommunication, be provided with anti -leakage flow -ball in the second runner, melt plastic flows into mould cavity along third runner, second runner and first runner in proper order, and the anti -leakage flow -ball is pushed into second runner when injection moulding, make that runner conduction, and the anti -leakage flow -ball is pushed back to third runner from second runner and realizes the closure to it when mould opening, and the runner mouth is blocked, prevent the melt in nozzle backflow and produce residual and overflow, guarantee the quality of next mould injection product.

Description

Technical Field

[0001] This utility model relates to the field of hot runner technology, specifically to a main nozzle structure for injection molds. Background Technology

[0002] In the stacked mold system, the main nozzle is directly connected to the injection molding machine's nozzle, forming the only channel for molten plastic to enter the mold. The tail of the main nozzle is fixedly installed in the middle of the hot runner plate by locking screws, forming a connecting bridge from the injection molding machine to the hot runner system. During injection, the molten plastic is ejected from the injection molding machine's nozzle, flows into the hot runner plate through the main nozzle, and is then distributed to the mold cavities of each layer.

[0003] For most hot runner stack mold systems, the limitation of insufficient injection distance usually requires lengthening the connection structure between the injection machine nozzle and the hot runner system to ensure that molten plastic is delivered from the hot runner system to the mold cavity. However, existing nozzles can cause decomposition and other adverse phenomena during long-distance injection, making it difficult to maintain the plastic in a molten state. Moreover, when the mold is opened and closed (when the injection machine nozzle and the hot runner system are open and closed), the inlet is exposed, which can lead to the problem of molten residual plastic flowing back and leaking, resulting in waste, affecting production efficiency and the quality of the plastic products obtained. Utility Model Content

[0004] The purpose of this utility model is to overcome the shortcomings of the prior art and provide a main nozzle structure for injection molds, which solves the problem of preventing the molten material in the nozzle from flowing back and leaving residue when the mold is opened and closed during the injection process, thus affecting the injection molded products of the next mold.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A main nozzle structure for injection molds includes a nozzle body, a middle insert, and a head insert connected sequentially along the axial direction. A first flow channel is formed on the inner side of the nozzle body. A second flow channel communicating with the first flow channel is formed on the inner side of the middle insert. A third flow channel communicating with the second flow channel is formed on the inner side of the head insert. A leak-proof guide ball is provided in the second flow channel. When the leak-proof guide ball moves into the third flow channel, it can close the third flow channel. When the leak-proof guide ball is located in the second flow channel, the second flow channel remains connected to the first flow channel.

[0006] Optionally, the second flow channel includes a guide section, a positioning section, and a diffusion section connected sequentially along the axial direction. The inner wall of the guide section is provided with a guide groove that communicates with the positioning section. The inner diameter of the positioning section is smaller than the outer diameter of the anti-leakage guide ball, and the guide section and the diffusion section are respectively connected to the third flow channel and the first flow channel.

[0007] Optionally, the third flow channel includes a direct current section and a limiting section. The direct current section is connected to the flow guiding section, and the limiting section is connected to the direct current section. The inner diameter of the direct current section is greater than or equal to the outer diameter of the anti-leakage flow guiding ball, and the inner diameter of the limiting section is smaller than the outer diameter of the anti-leakage flow guiding ball.

[0008] Optionally, the middle insert is detachably installed at the end of the nozzle body, and the head insert is detachably connected to the middle insert.

[0009] Optionally, a heating and temperature sensing component is provided on the outer side of the nozzle body, the middle insert, and the head insert.

[0010] Optionally, a protective sleeve is provided on the outer side of the nozzle body, the middle insert and the head insert, one end of the head insert extends to the outer side of the protective sleeve, and the heating and temperature sensing component is located on the inner side of the protective sleeve.

[0011] Optionally, a dustproof net is provided on the outer side of the protective sleeve.

[0012] Optionally, a guide sleeve is also provided on the outer side of the protective sleeve, and the guide sleeve is spaced apart from the dustproof net.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows: (1) Molten plastic flows into the mold cavity in sequence along the third runner, the second runner and the first runner. During injection, the molten material pushes the anti-leakage guide ball into the second runner. The runner opens the molten material into the first runner to ensure normal injection. When the mold is opened, the residual injection pressure in the runner is used to push the anti-leakage guide ball from the second runner to the third runner. After the anti-leakage guide ball enters the third runner, it seals the runner and blocks the runner opening to prevent the molten material in the nozzle from flowing back and generating residue and overflow, thus ensuring the quality of the injection molded product. (2) During injection molding, the anti-leakage guide ball enters the guide section and abuts against the port of the positioning section. At this time, the molten material enters the positioning section through the guide groove, and then flows along the positioning section to the diffusion section, and then enters the first flow channel. When the molten material passes through the guide groove and enters the diffusion section, the cross-sectional area increases, which can play the role of pressure reduction and throttling, preventing the plastic molten material from decomposing due to excessive connection distance, and improving the quality of injection molded products. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the main nozzle structure for injection molds in an embodiment of this utility model; Figure 2 This is a schematic diagram of the internal structure of the main nozzle structure for injection molds in an embodiment of this utility model; Figure 3 yes Figure 2Schematic diagram of the cross-sectional structure at section AA; Figure 4 This is an exploded structural diagram of the nozzle body, the middle insert, and the head insert in an embodiment of this utility model; Figure 5 This is a schematic diagram showing the position and structure of the nozzle body and the heating and temperature sensing component in an embodiment of this utility model; Figure 6 This is a schematic diagram of the structure of the anti-leakage guide ball located inside the head insert in this embodiment of the utility model; Figure 7 This is a schematic diagram of the structure of the anti-leakage guide ball located in the middle insert in this embodiment of the utility model; Figure 8 This is a schematic diagram of the main nozzle structure and the mold body position structure in an embodiment of this utility model; Figure 9 This is a schematic diagram showing the position of the main nozzle structure and the mounting block in an embodiment of this utility model; The components include: 1. Nozzle body; 101. First flow channel; 2. Middle insert; 201. Second flow channel; 211. Guide section; 212. Positioning section; 213. Diffusion section; 214. Guide groove; 202. First mounting hole; 3. Head insert; 301. Third flow channel; 311. Direct flow section; 312. Limiting section; 302. Second mounting hole; 4. Leak-proof guide ball; 5. Heating and temperature sensing component; 6. Protective sleeve; 7. Dustproof net; 8. Guide sleeve; 9. Shaft end retaining ring; 10. Mounting block; 11. End cap; 12. Mold body. Detailed Implementation

[0015] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. These drawings are simplified schematic diagrams, which are only used to illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0016] Example 1, as Figures 1-7 As shown, a main nozzle structure for injection molds includes a nozzle body 1, a middle insert 2, and a head insert 3. A first flow channel 101 is formed on the inner side of the nozzle body 1, a second flow channel 201 is formed on the inner side of the middle insert 2, and a third flow channel 301 is formed on the inner side of the head insert 3. The nozzle body 1, the middle insert 2, and the head insert 3 are connected sequentially along the axial direction. The first flow channel 101, the second flow channel 201, and the third flow channel 301 are also connected sequentially along the axial direction. The end of the nozzle body 1 away from the head insert 3 is connected to the mold body 12, and the end of the head insert 3 away from the nozzle body 1 can be connected to the nozzle of the injection molding machine. During injection, molten plastic is ejected from the nozzle of the injection molding machine, flows into the hot runner plate through the main nozzle, and is then distributed to each layer of the mold cavity. That is, the molten plastic flows into the mold cavity sequentially along the third flow channel 301, the second flow channel 201, and the first flow channel 101 for injection molding.

[0017] The second flow channel 201 is provided with a leak-proof guide ball 4. The leak-proof guide ball 4 can move axially between the second flow channel 201 and the third flow channel 301 under the drive of the residual pressure in the flow channel. When the leak-proof guide ball 4 moves into the third flow channel 301, it can close the third flow channel 301. When the leak-proof guide ball 4 moves into the second flow channel 201, the second flow channel 201 and the first flow channel 101 remain connected.

[0018] Specifically, during injection molding, the molten material pushes the anti-leakage guide ball 4 into the second runner 201. At this time, the second runner 201 and the first runner 101 remain connected, meaning the main runner is open, allowing the molten material to enter the first runner 101 and ensuring normal injection molding. When the mold opens, the residual injection pressure in the runner pushes the anti-leakage guide ball 4 from the second runner 201 back into the third runner 301. After entering the third runner 301, the anti-leakage guide ball 4 blocks the runner opening, sealing it off. This means the main runner is closed, preventing the molten material in the nozzle from flowing back and causing residue and overflow, thus achieving the anti-leakage function and ensuring the quality of the injection molded product.

[0019] As described above, the second flow channel 201 includes a guide section 211, a positioning section 212, and a diffuser section 213. The guide section 211 is connected to the third flow channel 301, and the diffuser section 213 is connected to the first flow channel 101. The guide section 211, the positioning section 212, and the diffuser section 213 are connected sequentially along the axial direction. A guide groove 214 is provided on the inner wall of the guide section 211. One end of the guide groove 214 extends into the positioning section 212, so that the guide groove 214 is connected to the positioning section 212. The inner diameter of the positioning section 212 is smaller than the outer diameter of the anti-leakage guide ball 4, and the inner diameter of the guide section 211 is larger than the outer diameter of the anti-leakage guide ball 4. The inner wall of the diffuser section 213 is a frustum, and its inner diameter gradually increases along the axial direction from the positioning section 212 to the first flow channel 101. The inner diameter of the end of the diffuser section 213 connected to the positioning section 212 is equal to the inner diameter of the positioning section 212.

[0020] When the anti-leakage guide ball 4 enters the guide section 211 of the second flow channel 201 under the driving force of injection pressure, it will abut against the port of the positioning section 212 to achieve a line seal. At this time, the first flow channel 101 and the third flow channel 301 are connected through the guide groove 214 and the diffuser section 213. The molten material enters the positioning section 212 through the guide groove 214, and then flows along the positioning section 212 to the diffuser section 213, and then enters the first flow channel 101. When the molten material passes through the guide groove 214 and enters the diffuser section 213, the cross-sectional area increases, which can play a role in reducing pressure and throttling, preventing the plastic molten material from decomposing due to excessive connection distance, and improving the quality of injection molded products.

[0021] Multiple guide channels 214 are provided, and the multiple guide channels 214 are arranged in a circular array around the axis of the second flow channel 201 to ensure that the molten material can smoothly enter the first flow channel 101.

[0022] The third flow channel 301 includes a direct flow section 311 and a limiting section 312. The limiting section 312 is connected to the direct flow section 311, and the direct flow section 311 is connected to the guide section 211. The injection molding machine nozzle is connected to the limiting section 312. The inner diameter of the direct flow section 311 is greater than or equal to the outer diameter of the anti-leakage guide ball 4, and the inner diameter of the limiting section 312 is less than the outer diameter of the anti-leakage guide ball 4.

[0023] When the inner diameter of the DC section 311 is larger than the outer diameter of the anti-leakage guide ball 4, it can promote the movement of the anti-leakage guide ball 4 in the DC section 311 until the anti-leakage guide ball 4 abuts against the port of the limiting section 312 to achieve a line seal, thereby closing the third flow channel 301, blocking the flow channel opening, and preventing overflow.

[0024] When the inner diameter of the DC section 311 is equal to the outer diameter of the anti-leakage guide ball 4, the anti-leakage guide ball 4 can also move within the DC section 311. At this time, the third flow channel 301 can be sealed by the line seal until it comes into contact with the port of the limiting section 312. This can both limit the flow and enhance the seal, thus improving the effect of preventing overflow.

[0025] Furthermore, the middle insert 2 is detachably installed at the end of the nozzle body 1, while the head insert 3 is detachably connected to the middle insert 2. The nozzle body 1, the middle insert 2, and the head insert 3 are all stepped shaft structures. The middle insert 2 has a first mounting hole 202 at the end near the nozzle body 1, and the head insert 3 has a second mounting hole 302 at the end near the middle insert 2. One end of the nozzle body 1 is inserted into the first mounting hole 202 to connect with the middle insert 2, and the end of the middle insert 2 away from the nozzle body 1 is inserted into the second mounting hole 302 to connect with the head insert 3. This connection adopts a detachable connection method, such as a threaded connection or an interference fit connection.

[0026] The length of the nozzle body 1 of this invention is greater than that of commonly available nozzles on the market. This extended design is intended to adapt to specific mold structures or production needs, such as scenarios where the front mold has a special, thick structure, or where the nozzle is connected over a long distance in inverted or stacked molds. The nozzle body 1 is made of a high-heat-resistant, high-tensile-strength, and corrosion-resistant stainless steel alloy material, and is located in the main body area of ​​the main nozzle structure and connected to the mold.

[0027] The head insert 3 is replaceable and its main inlet shape is customized according to customer requirements. It is made of high-hardness titanium alloy and is located at the head of the main nozzle structure to connect to the injection molding machine nozzle. The middle insert 2 is made of stainless steel and is located in the second part of the front end of the assembly. It adopts a special flow channel shape (such as adding a guide groove 214) to place the anti-leakage guide ball 4.

[0028] like Figures 1-7 As shown, a heating and temperature sensing component 5 is fitted on the outer side of the nozzle body 1, the middle insert 2, and the head insert 3. The heating and temperature sensing component 5 adopts existing technology and is fixedly connected to the nozzle body 1. It includes a heater and a temperature sensor and has the functions of heating and temperature sensing. Through the cooperation of the two functions, the plastic temperature in the corresponding area can be adjusted to maintain a constant temperature, so that the plastic remains in a molten state even during long-distance injection molding.

[0029] The nozzle body 1, the middle insert 2, and the head insert 3 are all covered with a protective sleeve 6. One end of the head insert 3 extends to the outside of the protective sleeve 6, and the heating and temperature sensing component 5 is located inside the protective sleeve 6. The protective sleeve 6 is made of stainless steel and its function is to protect the internal heater and temperature sensor (heating and temperature sensing component 5) from external impacts and the risk of contact with high temperatures.

[0030] The outer side of the protective sleeve 6 is fitted with a dustproof net 7 and a guide sleeve 8. The guide sleeve 8 and the dustproof net 7 are spaced apart. The dustproof net 7 is made of stainless steel and has the function of preventing the product from falling and getting burned when the mold is stacked. The guide sleeve 8 is made of bronze and plays an auxiliary guiding role when the mold is stacked. That is, the nozzle body 1, the middle insert 2, the head insert 3 and the heating and temperature sensing component 5 are as a whole and can move axially relative to the dustproof net 7 and the guide sleeve 8.

[0031] In addition, a shaft end retaining ring 9 is provided on the outer side of the head insert 3, which is fixed to the head insert 3 by a snap ring, and one end of the protective sleeve 6 is fitted on the outer side of the shaft end retaining ring 9, thereby playing the role of fixing the protective sleeve 6.

[0032] In Example 2, based on Example 1, this utility model also proposes a structure for assembling the main nozzle structure with the mold body 12.

[0033] like Figure 8 and Figure 9 As shown, the main nozzle is connected to the mold body 12 via the mounting block 10. The mounting block 10 is mounted on the mold body 12, and one end of the main nozzle extends through the mounting block 10 into the mold body 12 to achieve connection with its internal cavity.

[0034] Specifically, the inner side of the mounting block 10 has a through hole, both ends of the protective sleeve 6 extend through the through hole to the outer side of the mounting block 10, and the guide sleeve 8 is located at one end of the through hole and is fixedly connected to the mounting block 10 through the end cap 11, while the dustproof net 7 is located inside the through hole and is fixedly connected to the mounting block 10 through the flange.

[0035] In summary, this utility model proposes a main nozzle structure for injection molds, which enables pressure reduction and throttling of the molten plastic within the structure, as well as temperature control, maintaining the plastic in a molten state throughout long-distance injection molding processes. This reduces waste and improves production efficiency, resulting in high-quality plastic products. This structure is both simple and practical, overcoming the shortcomings of insufficient nozzle length, meeting the requirements of large systems, and ensuring stable transfer of molten plastic.

[0036] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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. Therefore, they should not be construed as limitations on this utility model.

[0037] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0038] Furthermore, 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 indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0039] Based on the preferred embodiments of this utility model described above, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A main nozzle structure for injection molds, characterized in that: The device includes a nozzle body, a middle insert, and a head insert connected sequentially along the axial direction. The nozzle body has a first flow channel on its inner side, the middle insert has a second flow channel communicating with the first flow channel on its inner side, and the head insert has a third flow channel communicating with the second flow channel on its inner side. A leak-proof guide ball is provided in the second flow channel. When the leak-proof guide ball moves into the third flow channel, it can close the third flow channel. When the leak-proof guide ball is located in the second flow channel, the second flow channel remains connected to the first flow channel.

2. The main nozzle structure for injection molds according to claim 1, characterized in that: The second flow channel includes a guide section, a positioning section, and a diffusion section that are connected sequentially along the axial direction. The inner wall of the guide section is provided with a guide groove that communicates with the positioning section. The inner diameter of the positioning section is smaller than the outer diameter of the anti-leakage guide ball. The guide section and the diffusion section are respectively connected to the third flow channel and the first flow channel.

3. The main nozzle structure for injection molds according to claim 2, characterized in that: The third flow channel includes a direct current section and a limiting section. The direct current section is connected to the flow guiding section, and the limiting section is connected to the direct current section. The inner diameter of the direct current section is greater than or equal to the outer diameter of the anti-leakage flow guiding ball, and the inner diameter of the limiting section is smaller than the outer diameter of the anti-leakage flow guiding ball.

4. The main nozzle structure for injection molds according to claim 1, characterized in that: The middle insert is detachably installed at the end of the nozzle body, and the head insert is detachably connected to the middle insert.

5. The main nozzle structure for injection molds according to claim 4, characterized in that: Heating and temperature sensing components are fitted on the outer sides of the nozzle body, the middle insert, and the head insert.

6. The main nozzle structure for injection molds according to claim 5, characterized in that: The nozzle body, the middle insert, and the head insert are all covered with protective sleeves. One end of the head insert extends to the outside of the protective sleeve, and the heating and temperature sensing component is located inside the protective sleeve.

7. The main nozzle structure for injection molds according to claim 6, characterized in that: The outer side of the protective sleeve is fitted with a dustproof net.

8. The main nozzle structure for injection molds according to claim 7, characterized in that: The protective sleeve is also fitted with a guide sleeve on its outer side, and the guide sleeve is spaced apart from the dustproof net.

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