A ring air cooling structure of a pipe extrusion die

Abstract

The utility model discloses a kind of annular air cooling structures of pipe extrusion die, belong to plastic pipe forming technical field. Including: spiral body component, it is made of spiral body and spiral body sleeve, spiral flow passage is formed between spiral body and spiral body sleeve;Expansion body component, it is made of outer expansion body and inner expansion body, melt flow passage is formed between outer expansion body and inner expansion body, spiral flow passage and melt flow passage are communicated;Annular groove is set on the connecting end surface of spiral body sleeve and outer expansion body, annular groove is close to the butt joint area of spiral flow passage and melt flow passage;Spiral body sleeve is set with the gas passage of annular groove intercommunication;Air pipe, it is installed in each gas passage and is used to carry out air cooling heat dissipation to annular groove. By air pipe direct introduction cooling air to annular groove area is forced air cooling, make heat dissipation effect focus on shear and friction heat most concentrated key position, significantly shorten heat conduction path, substantially improve heat exchange efficiency, effectively inhibit melt temperature abnormal rise.

Description

Technical Field

[0001] This utility model belongs to the field of plastic pipe forming technology, specifically relating to a circumferential air-cooled structure for a pipe extrusion die. Background Technology

[0002] During the operation of a spiral plastic pipe extrusion die, the melt flows through the spiral channel and at its outlet (i.e., the area near the channel where the spiral outer sleeve meets the outer expansion body of the die), significant shearing and frictional heat are generated due to the combined effect of the spiral structure and the narrow gap.

[0003] To address the aforementioned issues, existing technologies typically employ cooling methods on the outer surface of the mold and the inner surface of the mold core. However, since the cooling location is far from the actual heat-generating area and relies on indirect heat conduction, the heat exchange efficiency is low, making it difficult to effectively control local temperature rise. This not only easily leads to excessively high melt temperatures but may also cause quality problems such as product deformation and uneven wall thickness, thus hindering the improvement of production efficiency. Utility Model Content

[0004] This invention addresses the aforementioned problems in the existing technology by proposing a circumferential air-cooling structure for pipe extrusion dies that can effectively cool the temperature at the outlet of the spiral flow channel.

[0005] This utility model can be achieved through the following technical solutions:

[0006] A circumferential air-cooled structure for a pipe extrusion die includes:

[0007] A helical assembly, which consists of a helical body and a helical outer sheath, with a helical flow channel formed between the helical body and the helical outer sheath;

[0008] An expander assembly, which consists of an outer expander and an inner expander, wherein a melt flow channel is formed between the outer expander and the inner expander, and the spiral flow channel is connected to the melt flow channel;

[0009] The outer sheath of the spiral is connected to the outer expander, and the spiral is connected to the inner expander;

[0010] An circumferential groove is provided on the connecting end face of the spiral outer sleeve and the outer expander, and the circumferential groove is close to the docking area of ​​the spiral flow channel and the melt flow channel;

[0011] The outer sheath of the spiral body has several gas channels, and each gas channel is connected to the circumferential groove.

[0012] Air ducts are installed in each of the gas channels and are used to provide air cooling for the circumferential grooves.

[0013] As a further improvement of this utility model, the circumferential groove is formed separately on the end face of the spiral outer sleeve, or separately on the end face of the outer expansion body, or simultaneously on the end faces of the spiral outer sleeve and the outer expansion body.

[0014] As a further improvement of this utility model, at least one annular groove is provided. When the number of grooves is set to multiple, each annular groove is concentrically arranged and connected to the gas channel.

[0015] As a further improvement of this utility model, a plurality of gas channels are circumferentially distributed in the outer sheath of the spiral body.

[0016] As a further improvement of this utility model, one of the air ducts is configured as an exhaust duct connected to an external exhaust fan, and the remaining air ducts are configured as air inlet ducts.

[0017] As a further improvement of this utility model, an air volume regulating valve is provided on the air duct, and the air volume regulating valve is connected to the control system signal.

[0018] As a further improvement of this utility model, the outer wall of the external expansion body is provided with a plurality of thermocouples arranged circumferentially, and the thermocouples are connected to the control system signal.

[0019] As a further improvement of this utility model, the control system controls the opening and closing of the air volume regulating valve in the corresponding area according to the temperature detected by the thermocouple.

[0020] As a further improvement of this utility model, the circumferential groove is provided with a plurality of ribs, which are in contact with the spiral outer sleeve and / or the outer expander.

[0021] As a further improvement of this utility model, the rib is made of metal.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. Achieve precise and efficient cooling of high-heat areas: An annular groove is set near the junction of the spiral flow channel outlet and the melt flow channel, and cooling air is directly introduced through the air duct for forced air cooling. This focuses the heat dissipation on the key parts where shear and frictional heat are most concentrated, significantly shortening the heat conduction path, greatly improving heat exchange efficiency, and effectively suppressing abnormal rises in melt temperature.

[0024] 2. Achieve dynamic temperature field balance through zoned control of air volume regulating valves: Each air duct is equipped with an air volume regulating valve linked to the control system. Combined with the real-time temperature feedback of thermocouples arranged circumferentially on the outer expansion body, the cooling air volume of different circumferential areas can be independently adjusted—cooling is enhanced in high-temperature areas and air volume is reduced in low-temperature areas, thereby dynamically balancing the circumferential temperature distribution of the mold, avoiding wall thickness deviation or surface defects caused by uneven cooling, and significantly improving product quality.

[0025] 3. Metal ribs enhance thermal conductivity and heat exchange capacity: Metal ribs are set in the circumferential groove to contact the spiral outer shell and / or the outer expansion body. This not only increases the heat exchange area in contact with the cooling airflow, but also, thanks to the excellent thermal conductivity of metal, quickly conducts the locally accumulated heat to the airflow, further enhancing the convective heat dissipation effect, improving the thermal response speed and temperature uniformity, and ensuring the pipe forming accuracy and stability. Attached Figure Description

[0026] Figure 1 This is a cross-sectional view of the pipe extrusion die of this utility model;

[0027] Figure 2 This is the utility model Figure 1 A magnified view of a section at point A in the middle;

[0028] Figure 3 This is a cross-sectional view of the spiral sheath of this utility model.

[0029] In the diagram, 100 represents the helical body; 110 represents the outer casing of the helical body; and 120 represents the helical flow channel.

[0030] 200, outer expander; 210, inner expander; 300, melt flow channel;

[0031] 300. Circumferential groove; 310. Rib;

[0032] 400. Air duct; 410. Air volume regulating valve. Detailed Implementation

[0033] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. The technical methods of the present invention will be further described, but the present invention is not limited to these embodiments.

[0034] like Figures 1-3 As shown, this utility model provides a circumferential air-cooled structure for a pipe extrusion die, comprising:

[0035] The spiral assembly consists of a spiral body 100 and a spiral outer sleeve 110, with a spiral flow channel 120 formed between the spiral body 100 and the spiral outer sleeve 110;

[0036] An expander assembly is composed of an outer expander 200 and an inner expander 210, with a melt flow channel 220 formed between the outer expander 200 and the inner expander 210, and a spiral flow channel 120 connected to the melt flow channel 220.

[0037] The outer spiral shell 110 is connected to the outer expander 200, and the spiral 100 is connected to the inner expander 210;

[0038] An circumferential groove 300 is provided on the connecting end face of the spiral outer sleeve 110 and the outer expander 200, and the circumferential groove 300 is close to the docking area of ​​the spiral flow channel 120 and the melt flow channel 220;

[0039] The spiral outer casing 110 has several gas channels, each of which is connected to the circumferential groove 300.

[0040] The air duct 400 is installed in each gas passage and is used for air cooling of the circumferential groove 300.

[0041] By setting an annular groove 300 near the docking area between the spiral flow channel 120 outlet and the melt flow channel 220 where the heat is most concentrated, and by directly introducing air through the air duct 400 for forced air cooling, the cooling effect is precisely applied to the key parts where high shear and high frictional heat are generated, significantly shortening the heat conduction path and achieving efficient and direct heat dissipation of local high-temperature areas.

[0042] Compared with the indirect cooling method far from the heat source in the existing technology, this structure greatly improves the heat exchange efficiency, effectively suppresses the abnormal rise of melt temperature, thereby improving the tube forming quality, reducing defects such as deformation and uneven wall thickness caused by overheating, and helping to improve extrusion speed and production efficiency.

[0043] Preferably, the circumferential groove 300 is formed separately on the end face of the spiral outer sleeve 110, or separately on the end face of the outer expander 200, or simultaneously on the end faces of the spiral outer sleeve 110 and the outer expander 200. This design allows for flexible selection of the processing method based on the mold assembly structure and cooling requirements.

[0044] When the circumferential groove 300 is only provided on the outer sleeve 110 of the spiral body, it is convenient for processing and maintenance;

[0045] When the circumferential grooves 300 are distributed on the two end faces of the spiral outer sleeve 110 and the outer expansion body 200, they can form an annular air cavity with better sealing and larger volume after assembly. This helps the cooling airflow to be distributed more evenly around the entire flow channel outlet area, further improving the uniformity of cooling and heat exchange efficiency, and effectively alleviating the problem of local overheating.

[0046] Preferably, at least one annular groove 300 is provided. When the number of grooves is set to multiple, each annular groove 300 is concentrically arranged and connected to the gas channel. By setting multiple concentric annular grooves 300, a multi-layer cooling air ring can be formed around the outlet of the spiral flow channel 120, expanding the cooling coverage area and enhancing the radial and axial heat conduction control capability of the high shear heating area.

[0047] Meanwhile, since each circumferential groove 300 is connected to the gas channel, it can ensure that the cooling airflow is evenly distributed, avoid uneven local cooling, thereby more effectively stabilizing the melt temperature field, improving the uniformity of pipe wall thickness and surface quality, and adapting to the cooling requirements of different specifications or process conditions.

[0048] Preferably, multiple gas channels are circumferentially distributed in the outer sleeve of the spiral body 110. This arrangement allows cooling air to be evenly introduced into the circumferential groove 300 from multiple circumferential directions, ensuring a more uniform distribution of cooling airflow within the annular cavity. This avoids uneven cooling or vortex dead zones caused by unilateral air intake, thereby effectively improving the heat dissipation consistency of the entire mold circumference and further suppressing temperature fluctuations caused by shear heat concentration in the outlet area of ​​the spiral flow channel 120. This is beneficial for improving the dimensional stability and appearance quality of the tube forming.

[0049] To achieve a more precise cooling effect, this air-cooled system is also equipped with an airflow regulation mechanism, as detailed below:

[0050] First, one duct 400 is set as an exhaust duct 400 connected to an external exhaust fan, and the remaining ducts 400 are set as air inlets 400. When the exhaust fan is activated, outside air is drawn into the area where the annular groove 300 is located through each air inlet duct 400, and finally drawn out from the exhaust duct 400. Through the continuous airflow in the annular groove 300, the heat in the annular groove 300 is carried away, thereby achieving a good heat dissipation effect on the area where the heat is most concentrated, the spiral flow channel 120 outlet and the melt flow channel 220 docking area.

[0051] Secondly, an air volume regulating valve 410 is installed on the air duct 400, and the air volume regulating valve 410 is connected to the control system signal.

[0052] Finally, the outer wall of the expansion body 200 is provided with multiple thermocouples arranged circumferentially. The thermocouples are connected to the control system signal. The control system controls the opening and closing of the corresponding area air volume regulating valve 410 according to the temperature detected by the thermocouples.

[0053] It is worth mentioning that this layout allows for flexible adjustment of the cooling intensity at corresponding locations based on the actual temperature distribution in different areas around the mold.

[0054] By increasing the airflow in areas with higher local temperatures and decreasing the airflow in areas with lower temperatures, differentiated and precise cooling of different areas can be achieved, resulting in a significant effect on constant temperature control of the mold.

[0055] It also supports overall coordinated adjustment to adapt to the needs of different production conditions or pipe specifications, thereby significantly improving the responsiveness and adaptability of the cooling system, further ensuring the uniformity and stability of the temperature field at the outlet of the melt flow channel 220, and effectively improving the quality of pipe forming.

[0056] This design not only significantly improves thermal response speed and cooling uniformity, but also actively suppresses local overheating caused by uneven material flow or process fluctuations, thereby ensuring the consistency of pipe wall thickness, surface smoothness and overall forming stability.

[0057] Preferably, the circumferential groove 300 is provided with a plurality of ribs 310, the ribs 310 are in contact with the spiral outer sleeve 110 and / or the outer expander 200, and keep the air passage unobstructed, and the ribs 310 are made of metal.

[0058] The main function of the rib 310 is to expand the heat exchange area inside the circumferential groove 300. At the same time, by utilizing the excellent thermal conductivity of the metal material, the heat inside the circumferential groove 300 is efficiently transferred to the cooling airflow. By increasing the solid surface area in contact with the cooling air, the convective heat transfer effect is enhanced, thereby removing the heat generated by local friction and shear more quickly and evenly, effectively suppressing abnormal rise in melt temperature, and improving the forming accuracy and surface quality of the pipe.

[0059] The technical means disclosed in this utility model are not limited to those described above, but also include technical solutions composed of any combination of the above technical features. The above are specific embodiments of this utility model. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications are also considered within the scope of protection of this utility model.

[0060] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0061] Furthermore, in this utility model, the use of terms such as "first," "second," and "a" is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. The terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise explicitly specified. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0062] The technical solutions of the various embodiments of this utility model can be combined with each other, but only if they can be implemented by those skilled in the art. 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 protection scope claimed by this utility model.

[0063] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A circumferential air-cooled structure for a pipe extrusion die, characterized in that, include: A helical assembly, which consists of a helical body and a helical outer sheath, with a helical flow channel formed between the helical body and the helical outer sheath; An expander assembly, which consists of an outer expander and an inner expander, wherein a melt flow channel is formed between the outer expander and the inner expander, and the spiral flow channel is connected to the melt flow channel; The outer sheath of the helical body is connected to the outer expander, and the helical body is connected to the inner expander; An circumferential groove is provided on the connecting end face of the spiral outer sleeve and the outer expander, and the circumferential groove is close to the docking area of ​​the spiral flow channel and the melt flow channel; The outer sheath of the spiral body has several gas channels, and each gas channel is connected to the circumferential groove. Air ducts are installed in each of the gas channels and are used to provide air cooling for the circumferential grooves.

2. The circumferential air-cooled structure of a pipe extrusion die according to claim 1, characterized in that, The circumferential groove is formed separately on the end face of the spiral outer sleeve, or separately on the end face of the outer expander, or simultaneously on the end faces of the spiral outer sleeve and the outer expander.

3. The circumferential air-cooled structure of a pipe extrusion die according to claim 1, characterized in that, At least one annular groove is provided. When the number of grooves is set to multiple, each annular groove is concentrically arranged and is connected to the gas channel.

4. The circumferential air-cooled structure of a pipe extrusion die according to claim 1, characterized in that, Multiple gas channels are circumferentially distributed within the outer sheath of the helical body.

5. The circumferential air-cooled structure of a pipe extrusion die according to claim 1, characterized in that, One of the air ducts is configured as an exhaust duct connected to an external exhaust fan, and the remaining air ducts are configured as air inlet ducts.

6. The circumferential air-cooled structure of a pipe extrusion die according to claim 1, characterized in that, The air duct is equipped with an air volume regulating valve, which is connected to the control system signal.

7. The circumferential air-cooled structure of a pipe extrusion die according to claim 6, characterized in that, The outer wall of the expansion body is provided with multiple thermocouples arranged circumferentially, and the thermocouples are connected to the control system signals.

8. The circumferential air-cooled structure of a pipe extrusion die according to claim 7, characterized in that, The control system controls the opening and closing of the airflow regulating valve in the corresponding area based on the temperature detected by the thermocouple.

9. The circumferential air-cooled structure of a pipe extrusion die according to claim 1, characterized in that, The circumferential groove is provided with a number of ribs, which are in contact with the outer sheath of the spiral body and / or the outer expander.

10. The circumferential air-cooled structure of a pipe extrusion die according to claim 9, characterized in that, The ribs are made of metal.

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