Nozzle ventilation structure and injection molding machine

Abstract

The invention discloses a nozzle ventilation structure and an injection molding machine, the nozzle ventilation structure comprises a nozzle, an exhaust part and a sleeve, the exhaust part comprises ventilation steel and a support pipe made of a high temperature resistant material, the ventilation steel is provided with a through hole, the support pipe sleeves the ventilation steel, one end of the support pipe abuts against the nozzle, and the other end of the support pipe abuts against the sleeve. The supporting pipe comprises a ventilation section and supporting sections at the two ends of the ventilation section, the inner walls of the supporting sections are tightly connected with the ventilation steel, and ventilation gaps are formed between the inner walls of the ventilation sections and the ventilation steel so that a ventilation cavity can be formed between the supporting pipe and the ventilation steel. The support tube is provided with a ventilation cavity, the support tube is provided with a ventilation hole at the support section, the ventilation hole is communicated with the ventilation cavity, the sleeve is provided with an exhaust hole, and the exhaust hole is communicated with the ventilation hole. The nozzle ventilation structure provided by the invention can completely avoid glue overflow while realizing an exhaust function.

Description

Technical Field

[0001] This invention relates to the field of injection molding, and more specifically to a nozzle venting structure and an injection molding machine. Background Technology

[0002] Currently, the injection nozzle of a plastic injection machine is simply the final channel for plastic material. The material is extruded from here into different plastic molds, ultimately forming different plastic products. However, the injection of plastic material into the mold also introduces gas into the mold, creating air bubbles within the molded product and affecting its quality. The traditional solution to this problem is to install a venting device inside the mold. However, this venting method has drawbacks such as complex structure, high implementation difficulty and cost, and poor interoperability between different molds, resulting in limited flexibility and versatility.

[0003] In response, the applicant previously designed a nozzle device with a venting function (refer to patent document CN219133021U). A venting component is set in the first guide cavity of the sleeve. When the plastic material passes through the first guide cavity of the sleeve and then through the second guide cavity of the venting component, the gas can be discharged through the first venting hole on the sleeve under the high internal pressure of injection molding in the sleeve. This allows the gas generated in the molten state of the plastic material to be discharged before being extruded into different molds, reducing the product defect rate and ensuring the quality of injection molded products.

[0004] However, after long-term use, it was found that a small number of products would overflow with glue. After long-term and repeated experiments, the inventor improved the above structure and obtained a new technical solution that can achieve the venting function while completely avoiding glue overflow. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention provides a nozzle venting structure and an injection molding machine, which can realize the venting function while completely avoiding glue overflow.

[0006] The technical solution adopted by this invention to solve its technical problem is: A nozzle venting structure includes a nozzle, an exhaust component, and a sleeve. The nozzle and sleeve are hollow. The inner cavity of the sleeve includes an interconnected mounting cavity and a first flow guiding cavity. The diameter of the mounting cavity is larger than the diameter of the first flow guiding cavity to form a stepped structure at their connection. One end of the nozzle is connected to the mounting cavity. The exhaust component is disposed in the mounting cavity, with one end connected to the nozzle and the other end connected to the first flow guiding cavity. A second flow guiding cavity is disposed within the exhaust component. The inner cavity of the nozzle forms a third flow guiding cavity. The first, second, and third flow guiding cavities are interconnected to form a flow guiding channel. The exhaust component includes a permeable steel and a support tube made of a high-temperature resistant material. The permeable steel has a through hole to form the second flow guide cavity. The support tube is sleeved on the permeable steel. One end of the support tube abuts against the nozzle, and the other end abuts against the side wall of the mounting cavity. The support tube includes a permeable section and support sections at both ends of the permeable section. The inner wall of the support section is tightly connected to the permeable steel. There is a permeable gap between the inner wall of the permeable section and the permeable steel to form a permeable cavity between the support tube and the permeable steel. The support tube has a permeable hole at the support section, and the permeable hole communicates with the permeable cavity. The sleeve has an exhaust hole, and the exhaust hole communicates with the permeable hole.

[0007] A further improved technical solution is that the breathable steel has a cylindrical structure, the second guide cavity is arranged along its axis, and the diameter of the second guide cavity is smaller than the diameter of the first guide cavity.

[0008] A further improved technical solution is that the support tube is a circular tube structure, and the two ends of the breathable steel are interference-fitted with the inner walls of the two support sections of the support tube.

[0009] A further improved technical solution is that the vent hole is a strip-shaped hole, and the length direction of the strip-shaped hole is parallel to the axial direction of the ventilated steel.

[0010] A further improved technical solution is that multiple air vents are provided, and the multiple air vents are evenly distributed along the circumference of the support tube.

[0011] A further improved technical solution is that the diameter of the support tube is smaller than the diameter of the mounting cavity, so that an exhaust gap is formed between the support tube and the mounting cavity.

[0012] A further improved technical solution is that the sleeve is provided with multiple vent holes, and the multiple vent holes are evenly spaced along the axial direction of the sleeve to form a row of vent holes, and the sleeve is evenly distributed with multiple rows of vent holes along its circumference.

[0013] A further improved technical solution is that the diameter of the second guide cavity is greater than or equal to the diameter of the first guide cavity and the third guide cavity at the end connected to them.

[0014] A further improved technical solution is that a spiral guide rod is provided in the second guide cavity on the breathable steel, and the diameter of the spiral guide rod is larger than the diameter of the third guide cavity.

[0015] The present invention also provides a technical solution: an injection molding machine, including the nozzle ventilation structure of the above-mentioned technical solution.

[0016] The beneficial effects of this invention are as follows: A high-temperature resistant support tube is fitted onto the ventilated steel. Even after the ventilated steel deforms, both ends of the support tube remain tightly connected to the nozzle and sleeve, achieving a surface seal and thus preventing glue overflow. Furthermore, the venting gap, vent holes, and exhaust holes form an exhaust channel. When the molten plastic flows in the second guide cavity, the air in the plastic can be expelled through the exhaust channel under the pressure within the guide channel. Thus, the nozzle of this invention achieves the exhaust function while completely preventing glue overflow, greatly improving the product's practicality and commercial value. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is a structural exploded view of a nozzle ventilation structure according to an embodiment of the present invention; Figure 2 This is a cross-sectional view of a nozzle ventilation structure according to an embodiment of the present invention; Figure 3 yes Figure 2 Enlarged view of a portion of point A in the middle; Figure 4 This is a schematic diagram of the exhaust component of a nozzle ventilation structure according to an embodiment of the present invention; Figure 5 This is a cross-sectional view of an exhaust component of a nozzle ventilation structure according to an embodiment of the present invention; Figure 6 yes Figure 5 Enlarged view of a section at point B in the middle; Figure 7 yes Figure 5 MM cross-section; Figure 8 yes Figure 5 NN cross-section view.

[0019] Reference numerals: 100, nozzle; 110, first connecting part; 120, injection hole; 130, third guide cavity; 200, sleeve; 210, second connecting part; 220, vent hole; 230, first guide cavity; 240, connection port; 250, mounting cavity; 300, venting component; 310, support tube; 311, center hole; 312, vent hole; 320, ventilated steel; 321, second guide cavity; 330, spiral guide rod; 410, venting gap; 420, venting gap. Detailed Implementation

[0020] The following will clearly and completely describe the concept, specific structure, and technical effects of the present invention in conjunction with embodiments and accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention. Furthermore, all connections / linkages involved in the patent do not simply refer to direct contact between components, but rather to the ability to form a better connection structure by adding or reducing connecting accessories according to specific implementation conditions. For example, fixed connections / fixed installations can use screw connections, bolt connections, pin connections, key connections, adhesive connections, mortise and tenon connections, welding, riveting, etc., as needed. For detachable connections, screw connections, bolt connections, threaded connections, snap-fit ​​connections, mortise and tenon connections, Velcro connections, etc., as needed. The various technical features in this invention can be combined interactively without contradicting each other.

[0021] Reference Figures 1-8 An embodiment of the present invention provides an exhaust structure for a nozzle 100, including a nozzle 100, an exhaust component 300, and a sleeve 200. The nozzle 100 and sleeve 200 are hollow. One end of the nozzle 100 is provided with a first connecting portion 110, and one end of the sleeve 200 is provided with a second connecting portion 210. The first connecting portion 110 has an external thread, and the second connecting portion 210 has an internal thread. The first connecting portion 110 and the second connecting portion 210 are threadedly connected. The inner cavity of the sleeve 200 includes an interconnected mounting cavity 250 and a first guide cavity 230. The diameter of the mounting cavity 250 is larger than the diameter of the first guide cavity 230 to form a stepped structure at the connection between the two. One end of the nozzle 100 is connected to the mounting cavity 250. The exhaust component 300 is disposed in the mounting cavity 250, and one end of the exhaust component 300 is connected to the nozzle 100, and the other end is connected to the first guide cavity 230. A second guide cavity 321 is disposed inside the exhaust component 300. The inner cavity of the nozzle 100 forms a third guide cavity 130. The first guide cavity 230, the second guide cavity 321 and the third guide cavity 130 communicate with each other to form a guide channel.

[0022] It can be understood that when the molten plastic material flows from the first guide cavity 230 of the sleeve 200 into the second guide cavity 321 of the venting component 300, and then from the second guide cavity 321 into the third guide cavity 130 of the nozzle 100, the air in the plastic material can be discharged from the venting component 300 under the action of air pressure in the guide channel. After the gas is removed, the plastic material is injected into different molds from the nozzle 100, reducing the defect rate of user products and ensuring the quality of injection molded products.

[0023] In a specific embodiment, refer to Figures 2-7 The exhaust component 300 includes a cylindrical permeable steel 320 and a tubular support tube 310 made of high-temperature resistant material. The permeable steel 320 has a through hole along its axis, which forms the second flow guide cavity 321. When the molten plastic flows in the second flow guide cavity 321, the gas in the molten plastic can be discharged from the permeable steel 320 under high pressure because the permeable steel 320 is a porous metal material with interconnected micropores evenly distributed inside.

[0024] Additionally, refer to Figure 2 , Figures 4-7 In this embodiment, the ventilated steel 320 is fixed in the central hole 311 of the support tube 310. One end of the support tube 310 abuts against the nozzle 100, and the other end abuts against the side wall of the mounting cavity 250. Specifically, the support tube 310 includes a ventilated section and a support section integrally formed at both ends of the ventilated section. The inner wall of the support section is tightly connected to the ventilated steel 320 (connected by interference fit). There is a ventilated gap 420 between the inner wall of the ventilated section and the ventilated steel 320, so that a ventilated cavity is formed between the support tube 310 and the ventilated steel 320. The width H2 of the ventilated gap 420 is 0.14mm. The support tube 310 is provided with a vent hole 312 at the support section. The vent hole 312 communicates with the ventilated cavity. The sleeve 200 is provided with an exhaust hole 220, which communicates with the vent hole 312.

[0025] Understandably, when the molten plastic flows in the second guide cavity 321, under high pressure, the gas in the molten plastic can be discharged from the vent steel 320. The gas enters the vent cavity and then is discharged from the vent hole 312. Since the exhaust hole 220 is connected to the vent hole 312, the gas is discharged from the exhaust hole 220 on the sleeve 200.

[0026] In this embodiment, the support tube 310 is made of high-temperature resistant materials, such as nickel-based / cobalt-based high-temperature alloys, molybdenum alloys, alumina ceramics, and silicon carbide ceramics, which can remain undeformed in high-temperature molten plastic environments. After more than three years of repeated research and experimentation, the inventors determined that the overflow of adhesive in the existing nozzle 100 device is caused by the slight deformation of the ventilated steel 320 under prolonged exposure to high temperatures. Specifically, the two ends of the ventilated steel 320 collapse inwards, resulting in insufficient contact between the two ends of the ventilated steel 320 and the nozzle 100 and sleeve 200, leading to adhesive overflow. Therefore, by fitting a high-temperature resistant support tube 310 onto the ventilated steel 320, even after deformation, the two ends of the support tube 310 remain tightly connected to the nozzle 100 and sleeve 200 (the surface roughness of the contact surface is Ra0.1-0.5μm, and the contact gap is less than 0.005mm), achieving a surface seal and thus preventing adhesive overflow.

[0027] In some embodiments, refer to Figure 1 , Figure 4 and Figure 8 The vent 312 is a strip-shaped hole, and the length direction of the strip-shaped hole is parallel to the axial direction of the vent steel 320, thereby improving the exhaust effect; preferably, multiple vents 312 are provided, and the multiple vents 312 are evenly distributed around the support tube 310 to further improve the exhaust effect and prevent gas from accumulating in the vent cavity.

[0028] In some embodiments, refer to Figure 2 and Figure 3 The diameter of the support tube 310 is smaller than the diameter of the mounting cavity 250, so that an exhaust gap 410 is formed between the support tube 310 and the side wall of the mounting cavity 250. The thickness H1 of the exhaust gap 410 is 0.07 mm, and the gas discharged from the vent hole 312 will first enter the exhaust gap 410. The sleeve 200 is provided with a plurality of exhaust holes 220. The plurality of vent holes 312 are evenly spaced along the axial direction of the sleeve 200 to form a row of exhaust holes 220. The sleeve 200 is evenly provided with multiple rows of exhaust holes 220 along its circumference to improve the exhaust effect of the exhaust holes 220 and prevent gas from accumulating in the exhaust gap 410.

[0029] Preferred, refer to Figure 5 The outer diameter of the support section of the support tube 310 is larger than the outer diameter of the vent section. The support section of the support tube 310 is connected to the side wall of the mounting cavity 250 by a transition fit. The exhaust gap 410 between the vent section and the side wall of the mounting cavity 250 forms an exhaust cavity. This facilitates the installation of the support tube 310 and ensures that the second guide cavity 321 is as coaxial as possible with the first guide cavity 230 and the third guide cavity 130, thereby improving the flow effect of the molten plastic material.

[0030] It is understood that in this embodiment, after the gas is discharged from the vent steel 320, it first enters the vent chamber to diffuse and then is discharged from the vent hole 312. Similarly, the gas discharged from the vent hole 312 first enters the exhaust chamber to diffuse and then is discharged from the exhaust hole 220. This can improve the gas discharge effect.

[0031] In some embodiments, refer to Figure 2 The diameter of the second flow guide cavity 321 is greater than or equal to the diameter of the first flow guide cavity 230 and the third flow guide cavity 130 connected to it. Specifically, the first flow guide cavity 230 is a conical cavity structure, and its tip is connected to the second flow guide cavity 321 through the connection port 240. The diameter of the second flow guide cavity 321 is greater than the diameter of the connection port 240. The third flow guide cavity 130 is connected to an injection hole 120, and the diameter of the injection hole 120 is smaller than the diameter of the third flow guide cavity 130. By setting the above-mentioned flow guide channels, the injection pressure can be increased.

[0032] In this embodiment, refer to Figure 1 and Figure 2 A spiral guide rod 330 is provided in the second guide cavity 321 on the ventilated steel 320. The length of the spiral guide rod 330 is equal to the length of the ventilated steel 320, and the diameter of the spiral guide rod 330 is greater than the diameter of the third guide cavity 130. In this way, when the molten plastic flows in the second guide cavity 321, the spiral guide rod 330 can improve the discharge effect of the gas inside the molten plastic, and further improve the quality of injection molded products.

[0033] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A nozzle venting structure, comprising a nozzle, an exhaust component, and a sleeve, wherein the nozzle and the sleeve are hollow, the inner cavity of the sleeve includes an interconnected mounting cavity and a first guide cavity, and the diameter of the mounting cavity is larger than the diameter of the first guide cavity to form a stepped structure at the connection between the two, one end of the nozzle is connected to the mounting cavity, the exhaust component is disposed in the mounting cavity, and one end of the exhaust component is connected to the nozzle, and the other end is connected to the first guide cavity, a second guide cavity is disposed within the exhaust component, and the inner cavity of the nozzle forms a third guide cavity, the first guide cavity, the second guide cavity, and the third guide cavity are interconnected to form a guide channel, characterized in that: The exhaust component includes a permeable steel and a support tube made of a high-temperature resistant material. The permeable steel has a through hole to form the second flow guide cavity. The support tube is sleeved on the permeable steel. One end of the support tube abuts against the nozzle, and the other end abuts against the side wall of the mounting cavity. The support tube includes a permeable section and support sections at both ends of the permeable section. The inner wall of the support section is tightly connected to the permeable steel. There is a permeable gap between the inner wall of the permeable section and the permeable steel to form a permeable cavity between the support tube and the permeable steel. The support tube has a permeable hole at the support section, and the permeable hole communicates with the permeable cavity. The sleeve has an exhaust hole, and the exhaust hole communicates with the permeable hole.

2. The nozzle ventilation structure according to claim 1, characterized in that: The breathable steel has a cylindrical structure, and the second flow guide cavity is arranged along its axis. The diameter of the second flow guide cavity is smaller than the diameter of the first flow guide cavity.

3. The nozzle ventilation structure according to claim 2, characterized in that: The support tube is a circular tube structure, and the two ends of the breathable steel are interference-fitted with the inner walls of the two support sections of the support tube.

4. The nozzle ventilation structure according to claim 3, characterized in that: The vent is a strip-shaped hole, and the length direction of the strip-shaped hole is parallel to the axial direction of the vent-permeable steel.

5. The nozzle ventilation structure according to claim 4, characterized in that: The ventilation holes are provided in multiple ways, and the multiple ventilation holes are evenly distributed along the circumference of the support tube.

6. The nozzle ventilation structure according to claim 5, characterized in that: The diameter of the support tube is smaller than the diameter of the mounting cavity, so that an exhaust gap is formed between the support tube and the mounting cavity.

7. The nozzle ventilation structure according to claim 6, characterized in that: The sleeve is provided with multiple vent holes, and the multiple vent holes are evenly spaced along the axial direction of the sleeve to form a row of vent holes. The sleeve is provided with multiple rows of vent holes evenly distributed along its circumference.

8. The nozzle ventilation structure according to claim 7, characterized in that: The diameter of the second guide cavity is greater than or equal to the diameter of the first guide cavity and the third guide cavity at the end connected to them.

9. The nozzle ventilation structure according to claim 8, characterized in that: A spiral guide rod is provided in the second guide cavity on the breathable steel, and the diameter of the spiral guide rod is larger than the diameter of the third guide cavity.

10. An injection molding machine, characterized in that: Includes the nozzle ventilation structure as described in any one of claims 1-9.

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