Anti-casting nozzle of injection molding machine

Abstract

The utility model relates to an anti-casting nozzle of an injection molding machine, which comprises a hollow nozzle main body and a nozzle head connected to the front end of the nozzle main body, a flow guide column is fixedly arranged in the nozzle head, a perforation is axially formed in the flow guide column, one end of the perforation is communicated with the outside, and the other end of the perforation is in threaded connection with a plug. A piston cavity is formed in the position, corresponding to the side hole, in the nozzle head, a piston ring is slidably arranged on the portion, located on the flow guide column, in the piston cavity, a spring cavity is formed in the side, away from the nozzle body, of the piston cavity, and a spring abutting against the piston ring is arranged in the spring cavity. Automatic opening and closing of a perforation passage are achieved through cooperation of the spring and the piston ring, melt can be smoothly injected into a mold under the action of injection molding pressure, the piston ring timely resets to seal a runner under the action of the spring after the pressure disappears, and the casting phenomenon generated by dead weight or excess pressure of the melt after injection molding is completed is effectively prevented.

Description

Technical Field

[0001] This utility model relates to the field of injection molding machine technology, specifically to an anti-drip nozzle for injection molding machines. Background Technology

[0002] Injection molding, as a core process in polymer material processing, relies heavily on the performance of its core equipment, the injection molding machine, which directly impacts product quality and production efficiency. The nozzle, a crucial connecting component between the injection system and the mold, is responsible for injecting molten plastic into the mold cavity at high speed and with precision. However, after the injection holding phase, the negative pressure generated by the screw retraction and residual melt pressure can cause uncontrolled flow (i.e., "flow phenomenon") from the nozzle tip, leading to material waste, nozzle blockage, or flow marks on the product surface. Utility Model Content

[0003] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide an anti-drip nozzle for injection molding machines.

[0004] The objective of this utility model can be achieved through the following technical solution: an anti-drip nozzle for an injection molding machine, comprising a hollow nozzle body and a nozzle head connected to the front end of the nozzle body, a guide column fixedly provided inside the nozzle head, an injection hole axially opened inside the guide column, one end of the injection hole communicating with the outside, and a plug threaded to the other end, a side hole communicating with the injection hole radially opened on the guide column near the plug, a piston chamber provided inside the nozzle head at the position corresponding to the side hole, a piston ring slidably provided inside the piston chamber on the guide column, a spring chamber provided on the side of the piston chamber away from the nozzle body, and a spring abutting against the piston ring inside the spring chamber.

[0005] Preferably, a heating sleeve is provided on the outer side of the nozzle body.

[0006] Preferably, a filter screen is provided between the nozzle body and the nozzle head.

[0007] Preferably, the filter screen has a funnel-shaped structure.

[0008] Preferably, the end wall of the spring cavity is provided with a gasket that abuts against the spring.

[0009] The beneficial effects of this utility model are: the automatic opening and closing of the injection passage is achieved through the cooperation of the spring and the piston ring. Under the action of injection pressure, the melt can be smoothly injected into the mold. After the pressure is removed, the piston ring is reset in time under the action of the spring to close the flow channel, which effectively prevents the melt from flowing due to its own weight or residual pressure after injection. Its structural design is reasonable and compact and does not require external power control. The mechanical structure has high reliability and is easy to maintain. Attached Figure Description

[0010] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the structure of an anti-drip nozzle for an injection molding machine according to the present invention.

[0012] Figure 2 This is a cross-sectional view of an anti-drip nozzle for an injection molding machine according to the present invention.

[0013] Figure 3 This is a schematic diagram of the nozzle head structure of an anti-drip nozzle for an injection molding machine according to the present invention.

[0014] Figure 4 This is another schematic diagram of the nozzle head structure of the anti-drip nozzle of an injection molding machine according to the present invention.

[0015] The labels in the diagram represent: 1. Nozzle body; 2. Nozzle head; 3. Guide column; 4. Injection hole; 5. Plug; 6. Side hole; 7. Piston chamber; 8. Piston ring; 9. Spring chamber; 10. Spring; 11. Heating jacket; 12. Filter screen; 13. Gasket. Detailed Implementation

[0016] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0017] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0018] The technical solution of this utility model will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0019] See Figures 1 to 4As shown, the structure of this utility model is as follows: an anti-drip injection nozzle for an injection molding machine, comprising a hollow nozzle body 1 and an injection head 2 connected to the front end of the nozzle body 1. A guide column 3 is fixedly provided inside the injection head 2, and an injection hole 4 is axially formed inside the guide column 3. One end of the injection hole 4 communicates with the outside, and the other end is threadedly connected to a plug 5. A side hole 6 communicating with the injection hole 4 is radially formed on the guide column 3 near the plug 5. A piston chamber 7 is provided inside the injection head 2 at a position corresponding to the side hole 6. The piston chamber 7 slides on the guide column 3. A piston ring 8 is provided, and a spring cavity 9 is located on the side of the piston chamber 7 away from the nozzle body 1. A spring 10, which abuts against the piston ring 8, is located inside the spring cavity 9. Specifically, during injection molding, the melt enters the nozzle body 1 under high pressure. This pressure pushes the piston ring 8 to slide along the guide column 3 towards the spring cavity 9, compressing the spring 10. The piston ring 8 moves backward, exposing the side hole 6 of the guide column 3 and connecting it to the flow channel of the nozzle body 1. The melt then enters the injection hole 4 inside the guide column 3 through the side hole 6 and is injected into the mold cavity through the front end of the injection hole 4. After injection molding is completed, the melt pressure disappears, and the spring 10 rebounds, pushing the piston ring 8 to slide back to its initial position. The piston ring 8 completely covers the side hole 6, cutting off the connection between the injection hole 4 and the flow channel. Simultaneously, the plug 5 at the end of the guide column 3 prevents the piston ring 8 from excessively slipping. This process controls the opening and closing of the melt passage through the linkage of pressure and spring 10, physically sealing the flow channel at the moment of injection completion to prevent residual melt from dripping from the injection hole 4 due to gravity or residual pressure, achieving precise flow control.

[0020] like Figure 1 , Figure 2 As shown, a heating sleeve 11 is provided on the outer side of the nozzle body 1. Specifically, the heating sleeve 11 continuously heats the nozzle body 1 and the internal flow channel to maintain the temperature stability of the melt when it flows through the nozzle, and avoids the melt from increasing viscosity or solidifying locally due to temperature drop. This ensures smooth and uniform melt flow, which can prevent cold material from clogging the injection hole 4 or side hole 6 and affecting injection accuracy. It can also prevent the melt residue from sticking to the inside of the nozzle due to cooling and shrinkage when the melt flow is cut off, further improving the reliability of the anti-spraying effect.

[0021] like Figure 2 As shown, a filter screen 12 is provided between the nozzle body 1 and the nozzle head 2. Specifically, the filter screen 12 intercepts impurities or incompletely melted particles in the melt, preventing them from entering the precision flow channel structure such as the guide column 3, side hole 6, and injection hole 4 inside the nozzle head 2. This avoids flow channel blockage or piston ring 8 jamming caused by particle accumulation, thereby ensuring the stable operation of the anti-casting mechanism. At the same time, it reduces product defects caused by impurities entering the mold, extends the service life of the internal components of the nozzle, and reduces the maintenance frequency.

[0022] Furthermore, the filter screen 12 has a funnel-shaped structure. The shape of the funnel can guide the direction of melt flow, making the melt flow smoother and reducing pressure loss.

[0023] like Figure 2 As shown, the end wall of the spring cavity 9 is provided with a gasket 13 that abuts against the spring 10. Specifically, the preload of the spring 10 can be adjusted by changing the thickness of the gasket 13, thereby adapting to melts with different flowability. This prevents leakage of low-viscosity melts due to insufficient sealing pressure of the piston ring 8 caused by insufficient preload of the spring 10, and avoids flow restriction of high-flowability melts due to excessive preload of the spring 10.

[0024] In practical use, during injection molding, the molten material enters the nozzle body 1 under high pressure. This pressure pushes the piston ring 8 along the guide column 3 towards the spring cavity 9, compressing the spring 10. The piston ring 8 moves backward, exposing the side hole 6 of the guide column 3 and connecting it to the flow channel of the nozzle body 1. The molten material then enters the injection hole 4 inside the guide column 3 through the side hole 6 and is injected into the mold cavity through the front end of the injection hole 4. After injection molding is complete, the molten material pressure disappears, and the spring 10 rebounds, pushing the piston ring 8 to slide back to its initial position. The piston ring 8 completely covers the side hole 6, cutting off the connection between the injection hole 4 and the flow channel. Simultaneously, the plug 5 at the end of the guide column 3 prevents the piston ring 8 from slipping excessively. This process controls the opening and closing of the molten material passage through the linkage of pressure and spring 10, physically sealing the flow channel at the moment of injection completion to prevent residual molten material from dripping from the injection hole 4 due to gravity or residual pressure, achieving precise flow control.

[0025] The present invention has been further described above with reference to specific embodiments. However, it should be understood that the specific description herein should not be construed as limiting the substance and scope of the present invention. Various modifications made by those skilled in the art to the above embodiments after reading this specification are all within the scope of protection of the present invention.

Claims

1. An anti-drip nozzle for an injection molding machine, characterized in that: The nozzle body (1) includes a hollow nozzle body and a nozzle head (2) connected to the front end of the nozzle body (1). A guide column (3) is fixedly provided inside the nozzle head (2). An injection hole (4) is opened in the guide column (3) along the axial direction. One end of the injection hole (4) is connected to the outside, and the other end is threaded to a plug (5). A side hole (6) communicating with the injection hole (4) is radially opened on the guide column (3) near the plug (5). A piston chamber (7) is provided in the nozzle head (2) at the position corresponding to the side hole (6). A piston ring (8) is slidably provided in the piston chamber (7) on the guide column (3). A spring chamber (9) is provided on the side of the piston chamber (7) away from the nozzle body (1). A spring (10) is provided in the spring chamber (9) to abut against the piston ring (8).

2. The anti-drip nozzle for an injection molding machine according to claim 1, characterized in that: A heating sleeve (11) is provided on the outside of the nozzle body (1).

3. The anti-drip nozzle for an injection molding machine according to claim 1, characterized in that: A filter screen (12) is provided between the nozzle body (1) and the nozzle head (2).

4. The anti-drip nozzle for an injection molding machine according to claim 3, characterized in that: The filter screen (12) has a funnel-shaped structure.

5. The anti-drip nozzle for an injection molding machine according to claim 1, characterized in that: The end wall of the spring cavity (9) is provided with a gasket (13) that abuts against the spring (10).

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