An exhaust nozzle for preventing gas trapping and burning during injection molding

Abstract

The application discloses a gas-trapped and burned exhaust nozzle for injection molding, and relates to the technical field of injection molding, which comprises a nozzle body, a plurality of through holes are formed in the surface of the nozzle body, a cylinder is arranged in the through hole, a jet nozzle is fixedly arranged on one side of the nozzle body, an exhaust plate is arranged below the cylinder and in the through hole, a plurality of uniformly spaced exhaust holes are formed in the middle of the exhaust plate, and the exhaust holes are communicated with the main injection flow channel in the nozzle body; the application has the beneficial effects that: during the injection molding process, the air in the main injection flow channel can be quickly discharged outward through the uniformly distributed exhaust holes on the exhaust plate, local high temperature caused by the compression of trapped air is avoided, plastic melt burning is effectively prevented, product surface black spots and ablation marks are eliminated, the melt flow state is stabilized, molding defects such as material flowers, flow lines and welding marks are reduced, and the appearance quality and molding yield of products are significantly improved.

Description

Technical Field

[0001] This invention relates to an exhaust nozzle, and more particularly to an exhaust nozzle for injection molding that prevents trapped air from burning, belonging to the field of injection molding technology. Background Technology

[0002] In the injection molding process, the nozzle is a crucial component connecting the barrel and the mold cavity. Molten plastic must be injected into the mold through the nozzle to complete the product molding. For the injection molding of certain special materials, existing nozzles still have significant shortcomings in practical use: Firstly, enclosed spaces easily form inside and at the front end of the nozzle flow channel. When molten plastic is injected at high speed, air inside the flow channel cannot be expelled in time, resulting in trapped air. Under high temperature and pressure, the trapped air is rapidly compressed, generating localized high temperatures, which directly causes the plastic melt to scorch, resulting in black spots and ablation marks on the product surface, severely affecting the product's appearance and structural strength. Furthermore, trapped air disrupts the continuity of melt flow, causing the molten plastic to form turbulent and chaotic flow within the flow channel, which in turn produces defects such as flow marks, flow lines, and weld lines on the product surface, reducing the product's molding yield. Secondly, most existing nozzles have a single-channel structure without a specific venting design. Their venting capacity depends on the mold's venting groove. When the mold's venting groove is insufficient or blocked, the problem of trapped air cannot be effectively alleviated, limiting their applicability and making it difficult to meet the stable production needs of injection molding of special materials. Summary of the Invention

[0003] The purpose of this invention is to provide an injection nozzle for preventing trapped air and scorching during injection molding, thereby solving the following problems mentioned in the background art: First, the nozzle flow channel easily forms a closed space, trapping air when molten plastic is injected at high speed. Under high temperature and pressure, the trapped air is compressed, causing the plastic to scorch and black spots to appear on the product surface, affecting its appearance and strength. Trapped air also disrupts the continuity of melt flow, causing various defects on the product surface and reducing the molding yield. Second, most existing nozzles are single-channel without venting design, relying on the mold venting groove for venting. When the venting groove is insufficient or blocked, trapped air is difficult to alleviate, limiting its application range and making it difficult to meet the problem of stable production of special materials in injection molding.

[0004] To achieve the above objectives, the present invention provides the following technical solution: an venting nozzle for injection molding to prevent trapped air and scorching, comprising a nozzle body, wherein a plurality of through holes are formed on the surface of the nozzle body, a cylinder is provided inside the through holes, a spray nozzle is fixedly provided on one side of the nozzle body, an venting plate is provided below the cylinder and inside the through holes, a plurality of evenly spaced venting holes are formed in the middle of the venting plate, the venting holes are connected to the main injection flow channel inside the nozzle body, a sealing component is provided on the surface of the venting plate, a hexagonal bolt groove is formed at the top of the cylinder, and a sealing plug is provided above the hexagonal bolt groove.

[0005] As a preferred embodiment of the present invention, the number of exhaust holes is four, and the four exhaust holes are evenly distributed along the circumference of the nozzle body, and the diameter of the exhaust holes is 0.01-0.03mm.

[0006] As a preferred embodiment of the present invention, the bottom of the cylinder is provided with an external thread, and the inner wall of the through hole is provided with a threaded groove that is threadedly connected to the external thread.

[0007] As a preferred embodiment of the present invention, the sealing assembly includes a first sealing ring, which is fixedly installed on the top of the exhaust plate, and a second sealing ring is fixedly provided on the side of the top of the exhaust plate.

[0008] As a preferred embodiment of the present invention, the bottom end of the cylinder is provided with a washer, and the bottom end of the washer is provided with a first sealing groove and a second sealing groove corresponding to the first sealing ring and the second sealing ring.

[0009] As a preferred embodiment of the present invention, the bottom of the sealing plug is provided with a rotating assembly, the rotating assembly including a rotating seat, the rotating seat being disposed at the bottom of the sealing plug, and the bottom end of the rotating seat being fixedly connected to the surface of the nozzle body.

[0010] As a preferred embodiment of the present invention, the rotating base is provided with a rotating plate inside, and a support cap is fixedly provided at the top of the rotating plate, and the sealing plug is fixedly connected to the support cap.

[0011] As a preferred embodiment of the present invention, a strong magnetic column is fixedly provided on one side of the bottom end of the support cap, the strong magnetic column is magnetically connected to the nozzle body, and the sealing plug is made of rubber.

[0012] Compared with related technologies, the venting nozzle for injection molding that prevents trapped gas from burning has the following beneficial effects: During the injection molding process, the air in the main injection channel can be quickly discharged to the outside through the evenly distributed vent holes on the vent plate, avoiding the compression of trapped air and the generation of local high temperature, effectively preventing the plastic melt from burning, eliminating black spots and burning marks on the product surface, stabilizing the melt flow state, reducing molding defects such as material flow marks, flow lines, and weld lines, and significantly improving the product appearance quality and molding yield. This invention no longer relies entirely on mold venting channels for venting. Through its integrated independent venting channel, it maintains stable venting even when mold venting is insufficient or venting channels are blocked, significantly expanding the nozzle's applicability and meeting the injection molding needs of various special materials. Secondly, the rubber sealing plug, combined with the rotating assembly and strong magnetic column, can seal the through-hole when the machine is stopped, preventing impurities from entering and clogging the venting holes. The overall structure is easy to assemble and disassemble, and simple to maintain, improving injection molding stability and production efficiency while extending the nozzle's service life. Attached Figure Description

[0013] Figure 1 This is one of the structural schematic diagrams of the present invention; Figure 2 This is a schematic diagram of the exploded structure of the nozzle body of the present invention; Figure 3 This is an exploded structural diagram of the exhaust plate of the present invention; Figure 4 This is the second structural schematic diagram of the present invention; Figure 5 For the present invention Figure 4 A magnified structural diagram at point A; Figure 6 This is a schematic diagram of the rubber stopper structure of the present invention.

[0014] In the diagram: 1. Nozzle body; 2. Through hole; 3. Cylindrical; 4. Nozzle; 5. Exhaust plate; 6. Exhaust hole; 7. Sealing assembly; 701. First sealing ring; 702. Second sealing ring; 703. Washer; 8. Hexagonal bolt groove; 9. External thread; 10. Sealing plug; 11. Rotating assembly; 1101. Rotary seat; 1102. Rotating plate; 1103. Support cap; 1104. Strong magnetic column. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] Please see Figures 1-6 This invention provides an venting nozzle for injection molding to prevent trapped air and scorching, comprising a nozzle body 1, a plurality of through holes 2 on the surface of the nozzle body 1, a cylinder 3 inside the through holes 2, a spray nozzle 4 fixedly mounted on one side of the nozzle body 1, an venting plate 5 below the cylinder 3 and inside the through holes 2, a plurality of evenly spaced venting holes 6 in the middle of the venting plate 5, the venting holes 6 communicating with the main injection flow channel inside the nozzle body 1, a sealing component 7 on the surface of the venting plate 5, a hexagonal bolt groove 8 on the top of the cylinder 3, and a sealing plug 10 above the hexagonal bolt groove 8; By setting a through hole 2 with a cylinder 3 on the nozzle body 1, and integrating an exhaust plate 5 with an exhaust hole 6 inside the through hole 2, active and controllable gas discharge during injection molding can be achieved. During injection molding, trapped gas in the main injection channel can be quickly discharged through the exhaust hole 6 on the exhaust plate 5, avoiding melt scorching caused by gas compression and heating, and effectively eliminating black spots and burning marks on the product surface. At the same time, uniform venting can stabilize the melt flow state and reduce molding defects such as material flow marks, flow lines, and weld lines. The cylinder 3 can fix the installation state of the exhaust plate 5, and together with the sealing component 7, it can ensure the sealing between the exhaust plate 5 and the nozzle body 1 during use, playing a role in dust prevention. The hexagonal bolt groove 8 at the top provides a convenient operating position for the cylinder 3, facilitating installation and maintenance. The sealing plug 10 can seal the through hole 2 when the machine is stopped or not in operation, preventing impurities from entering the exhaust hole 6 and causing blockage, thus improving the reliability and service life of the structure.

[0017] There are four vent holes 6, and the four vent holes 6 are evenly distributed along the circumference of the nozzle body 1. The diameter of the vent holes 6 is 0.01-0.03mm. By setting four vent holes 6 and distributing them evenly around the circumference of the nozzle body 1, the gas in the main injection channel can be discharged evenly in the circumference, avoiding melt turbulence caused by poor local venting, ensuring uniform pressure distribution in the flow field, and further reducing the probability of trapped gas, scorching, and molding defects. The orifice diameter is set to 0.01-0.03mm, which can meet the need for rapid gas discharge during injection molding, and effectively prevent the overflow of molten plastic, preventing problems such as overflow and flash. It takes into account both venting efficiency and leak prevention performance, adapts to plastic materials with different flowability, and improves the versatility and practicality of the structure.

[0018] The bottom of the cylinder 3 is provided with an external thread 9, and the inner wall of the through hole 2 is provided with a threaded groove that is threadedly connected to the external thread 9. The cylinder 3 is threadedly connected to the threaded groove on the inner wall of the through hole 2 via the external thread 9 at its bottom. The axial position can be adjusted by rotating the cylinder 3. On the one hand, the contact pressure between the cylinder 3 and the vent plate 5 can be controlled by the screw depth of the cylinder 3, thereby adjusting the tightness of the fit of the vent plate 5 to meet the venting requirements under different injection pressures. On the other hand, the threaded connection structure has a self-locking function, which can prevent the cylinder 3 from loosening due to vibration during injection molding and ensure the working stability of the venting structure. At the same time, this connection method facilitates the disassembly and replacement of the cylinder 3 and the vent plate 5, simplifies the maintenance process, and reduces the later maintenance cost.

[0019] The sealing assembly 7 includes a first sealing ring 701, which is fixedly installed on the top of the exhaust plate 5. A second sealing ring 702 is fixedly provided on the side of the top of the exhaust plate 5. A washer 703 is provided at the bottom of the cylinder 3. A first sealing groove and a second sealing groove corresponding to the first sealing ring 701 and the second sealing ring 702 are opened at the bottom of the washer 703. The first sealing ring 701, the second sealing ring 702, and the corresponding sealing grooves on the gasket 703 form a double sealing structure: the cooperation of the first sealing ring 701 and the first sealing groove can achieve the sealing of the central area of ​​the vent plate 5, preventing the melt from leaking from the periphery of the vent hole 6; the cooperation of the second sealing ring 702 and the second sealing groove can achieve the sealing of the edge area of ​​the vent plate 5, blocking the leakage path of the melt along the gap between the vent plate 5 and the inner wall of the through hole 2. The double sealing structure greatly improves the leak-proof performance of the venting structure and effectively avoids product defects and equipment contamination caused by melt leakage during injection molding.

[0020] The bottom of the sealing plug 10 is provided with a rotating assembly 11, which includes a rotating seat 1101. The rotating seat 1101 is disposed at the bottom of the sealing plug 10, and the bottom end of the rotating seat 1101 is fixedly connected to the surface of the nozzle body 1. A rotating plate 1102 is rotatably provided inside the rotating seat 1101, and a support cap 1103 is fixedly provided at the top of the rotating plate 1102. The sealing plug 10 is fixedly connected to the support cap 1103. A strong magnetic column 1104 is fixedly provided on one side of the bottom end of the support cap 1103. The strong magnetic column 1104 is magnetically connected to the nozzle body 1. The sealing plug 10 is made of rubber. The sealing plug 10 can be easily opened, closed, and positioned by rotating component 11: In the injection molding working state, the rotating plate 1102 can be rotated to drive the support cap 1103 and the sealing plug 10 to disengage from the top of the through hole 2, keeping the through hole 2 open and not affecting the normal operation of the exhaust structure; In the shutdown or maintenance state, the rotating plate 1102 can be rotated to align the sealing plug 10 and insert it into the top of the through hole 2. The rubber sealing plug 10 can form an interference fit with the inner wall of the through hole 2 to close the through hole 2 and prevent impurities from entering and causing blockage of the exhaust hole 6; The strong magnetic column 1104 at the bottom of the support cap 1103 can be magnetically attracted to the nozzle body 1 to ensure that the sealing plug 10 is fixed in the closed state, avoiding the sealing plug 10 from falling off due to external force or vibration, thus improving the reliability of the structure.

[0021] When in use, the exhaust plate 5 with the sealing assembly 7 assembled is placed into the through hole 2 on the surface of the nozzle body 1. The position of the exhaust plate 5 is adjusted so that the several exhaust holes 6 in the middle of the exhaust plate 5 are fully connected with the main injection flow channel inside the nozzle body 1, so that the gas can be smoothly discharged. Then, align the external thread 9 at the bottom of cylinder 3 with the thread groove on the inner wall of through hole 2. Using a hexagonal bolt slot 8 at the top of cylinder 3, rotate cylinder 3 with a hexagonal wrench to slowly screw cylinder 3 into through hole 2 until the washer 703 at the bottom of cylinder 3 is completely fitted with the sealing component 7 at the top of exhaust plate 5. At this time, the first sealing groove and the second sealing groove at the bottom of washer 703 precisely match the first sealing ring 701 and the second sealing ring 702 respectively, forming a double sealing structure to ensure that there is no gap between exhaust plate 5 and nozzle body 1 and cylinder 3, thus preventing melt leakage. After assembly, the exhaust nozzle is installed in the corresponding position on the injection molding machine to ensure that the nozzle body 1 is precisely connected to the injection system of the injection molding machine and that the main injection flow channel is unobstructed. Before the injection work begins, rotate the support cap 1103 to drive the support cap 1103 and the sealing plug 10 to disengage from the top of the through hole 2, so that the through hole 2 remains open. At the same time, ensure that the strong magnetic column 1104 is demagnetized from the nozzle body 1 so as not to affect the normal operation of the exhaust structure. Then, the injection molding machine is started. The molten plastic enters the nozzle body 1 through the main injection channel and flows towards the nozzle 4 under the injection pressure. At this time, the trapped air in the main injection channel will be quickly discharged through the four circumferentially evenly distributed vent holes 6 on the vent plate 5 under the pressure, realizing the active and controllable discharge of gas, avoiding the problem of melt burning caused by gas compression and heating, and effectively eliminating black spots and burning marks on the product surface. At the same time, uniform venting can stabilize the melt flow state, reduce molding defects such as material flow marks, flow lines, and weld lines, and ensure the quality of injection molded products. When the injection molding work is completed or the machine needs to be stopped for maintenance, first turn off the injection molding machine. After the molten plastic in the main injection channel cools and solidifies, rotate the turntable 1102 to drive the support cap 1103 and the sealing plug 10 to the top of the through hole 2. Align the rubber sealing plug 10 and insert it into the through hole 2 so that the sealing plug 10 forms an interference fit with the inner wall of the through hole 2, thereby sealing the through hole 2. Fix the position of the sealing plug 10 to prevent it from falling off due to external force or vibration, prevent impurities from entering the vent hole 6 and causing blockage, and protect the venting structure.

[0022] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A venting nozzle for injection molding to prevent trapped gas from burning, comprising a nozzle body (1), characterized in that, The surface of the nozzle body (1) is provided with several through holes (2), and a cylinder (3) is provided inside the through holes (2). A spray nozzle (4) is fixed on one side of the nozzle body (1). An exhaust plate (5) is provided below the cylinder (3) and inside the through holes (2). Several evenly spaced exhaust holes (6) are provided in the middle of the exhaust plate (5). The exhaust holes (6) are connected to the main injection flow channel inside the nozzle body (1). A sealing component (7) is provided on the surface of the exhaust plate (5). A hexagonal bolt groove (8) is provided on the top of the cylinder (3). A sealing plug (10) is provided above the hexagonal bolt groove (8).

2. The venting nozzle for injection molding to prevent trapped gas from burning, as described in claim 1, is characterized in that: The number of exhaust holes (6) is four, and the four exhaust holes (6) are evenly distributed along the circumference of the nozzle body (1). The diameter of the exhaust holes (6) is 0.01-0.03mm.

3. The venting nozzle for injection molding to prevent trapped gas from burning, as described in claim 1, is characterized in that: The bottom of the cylinder (3) is provided with an external thread (9), and the inner wall of the through hole (2) is provided with a threaded groove that is threadedly connected to the external thread (9).

4. The venting nozzle for injection molding to prevent trapped gas from burning, as described in claim 1, is characterized in that: The sealing assembly (7) includes a first sealing ring (701), which is fixedly installed on the top of the exhaust plate (5), and a second sealing ring (702) is fixedly provided on the side of the top of the exhaust plate (5).

5. The venting nozzle for injection molding to prevent trapped gas from burning, as described in claim 1, is characterized in that: The bottom end of the cylinder (3) is provided with a washer (703), and the bottom end of the washer (703) is provided with a first sealing groove and a second sealing groove corresponding to the first sealing ring (701) and the second sealing ring (702).

6. The venting nozzle for injection molding to prevent trapped gas from burning, as described in claim 1, is characterized in that: The bottom of the sealing plug (10) is provided with a rotating assembly (11), which includes a rotating seat (1101). The rotating seat (1101) is located at the bottom of the sealing plug (10), and the bottom end of the rotating seat (1101) is fixedly connected to the surface of the nozzle body (1).

7. The venting nozzle for injection molding to prevent trapped gas from burning, as described in claim 6, is characterized in that: The rotating base (1101) has a rotating plate (1102) inside, and a support cap (1103) is fixedly provided at the top of the rotating plate (1102). The sealing plug (10) is fixedly connected to the support cap (1103).

8. The venting nozzle for injection molding to prevent trapped gas from burning, as described in claim 7, is characterized in that: A strong magnetic column (1104) is fixedly provided on one side of the bottom end of the support cap (1103). The strong magnetic column (1104) is magnetically connected to the nozzle body (1). The sealing plug (10) is made of rubber.

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