Plastic pipe extrusion die

Abstract

The application belongs to the technical field of plastic pipe production and discloses a plastic pipe extrusion die. The expanding die comprises a connecting part, a transition part and an expanding part. The connecting part is detachably connected to the end of the discharge port of the plastic extruder with adjustable inner diameter. The transition part is located at the end of the connecting part away from the discharge port of the plastic extruder with adjustable inner diameter. The expanding part is located at the end of the transition part away from the connecting part and is used for expanding the inner diameter of the plastic pipe. By reducing the inner diameter of the plastic extruder with adjustable inner diameter, the wall thickness of the extruded pipe is increased, thereby reducing the internal structural pressure of the plastic extruder with adjustable inner diameter. The pressure is shared externally by the expanding die. When the expanding die is replaced or repaired, the problem of the reduced service life of the extruder and the shortened maintenance cycle caused by the high pressure of the extruder for extruding the plastic pipe with small wall thickness for a long time is solved.

Description

Technical Field

[0001] This utility model belongs to the field of plastic pipe production technology, specifically relating to a plastic pipe extrusion mold. Background Technology

[0002] Currently, the main types of plastic pipes used in China are polyethylene (PE), polyvinyl chloride (PVC), and random copolymer polypropylene (PP-R). Extruders are typically used for the production of plastic pipes, and are a type of plastic machinery. Extruders can be classified into right-angle extruders and angled extruders based on the angle between the material flow direction at the die head and the screw centerline. Screw extruders rely on the pressure and shear force generated by the rotating screw to fully plasticize and uniformly mix the material, which is then formed through a die. Plastic extruders can be broadly classified into twin-screw extruders, single-screw extruders, and less common multi-screw extruders and screwless extruders.

[0003] In existing technologies, such as Chinese invention patent CN120134574B, a plastic pipe forming machine is disclosed. Specifically, this invention relates to the field of plastic pipe forming technology, specifically to a plastic pipe forming machine comprising a feeding device, a spiral extrusion device, an extrusion head, and a stretching and expanding device connected sequentially along the material travel direction. A traction device is provided on one side of the feeding port of the stretching and expanding device. This invention, through the arrangement of the extrusion head and the stretching and expanding device, can continuously complete the extrusion forming, diameter expansion, and biaxial orientation of plastic pipes, achieving continuous industrial production. Because the tensile strength and initial modulus in the orientation direction are significantly improved, and the elongation at break is reduced, it solves the problems of long production cycles and low production efficiency of existing large-diameter plastic pipes while ensuring the production quality of large-diameter plastic pipes.

[0004] However, in the process of extruding plastic pipes, when producing plastic pipes with smaller wall thicknesses, the extruder uses high pressure to extrude the pipes. Prolonged high pressure can lead to a reduction in the extruder's service life and a shorter maintenance cycle. Summary of the Invention

[0005] Based on this, this application provides a plastic pipe extrusion die to solve the problem that in the production of plastic pipes with small wall thickness, the extruder uses high pressure for extrusion, and prolonged high pressure will lead to a reduction in the service life of the extruder and a shorter maintenance cycle.

[0006] The technical solution to the above-mentioned technical problems in this application is as follows:

[0007] A plastic pipe extrusion die is disposed at the end of the discharge port of a plastic extruder with adjustable inner diameter. The die includes an expanding die comprising a connecting portion, a transition portion, and an expanding portion. The connecting portion is detachably connected to the end of the discharge port of the plastic extruder with adjustable inner diameter, and the axis of the connecting portion coincides with the axis of the discharge port of the plastic extruder with adjustable inner diameter. The transition portion is located at the end of the connecting portion away from the discharge port of the plastic extruder with adjustable inner diameter, and the outer diameter of the transition portion is the same as the inner diameter of the discharge port of the plastic extruder with adjustable inner diameter. The expanding portion is located at the end of the transition portion away from the connecting portion, and the expanding portion is used to expand the inner diameter of the plastic pipe.

[0008] Preferably, it further includes an auxiliary sleeve, which is fitted onto the expanding die and detachably connected to one end of the discharge port of the plastic extruder with adjustable inner diameter. The axis of the auxiliary sleeve coincides with the axis of the expanding die, and the inner diameter of the auxiliary sleeve is the same as the outer diameter of the plastic tube.

[0009] Preferably, an extension sleeve is detachably provided at the end of the auxiliary sleeve away from the discharge port of the plastic extruder with adjustable inner diameter, and the length of the extension sleeve is flush with the end of the expanded diameter portion away from the transition portion.

[0010] Preferably, the connecting part extends through the transition part and the enlarged diameter part, and is threadedly engaged with the end of the discharge port of the plastic extruder with adjustable inner diameter.

[0011] Preferably, a plurality of diameter-expanding blocks are detachably connected to the end of the diameter-expanding portion away from the transition portion, and the outer diameter of the plurality of diameter-expanding blocks increases sequentially in the direction away from the transition portion.

[0012] Preferably, a plurality of extension sleeves are provided, and adjacent extension sleeves are detachably connected by a connector. The extension sleeve at the end away from the auxiliary sleeve is flush with one end of the expansion block, and the inner diameter of the extension sleeve changes in the same way as the outer diameter of the expansion block.

[0013] Preferably, the connector is a connecting flange.

[0014] Preferably, the connector is a screw, the extended sleeve is provided with several through holes, the auxiliary sleeve is provided with a threaded hole, and the screw passes through the through holes and is connected to the threaded hole.

[0015] The technical solution adopted in this application can achieve the following beneficial effects:

[0016] By reducing the inner diameter of an adjustable-diameter plastic extruder, the wall thickness of the extruded material increases, thereby reducing the internal structural pressure of the extruder. Then, by using an expanding die, the inner diameter of the plastic tube is enlarged outside the extruder, further reducing the wall thickness. This ensures that the inner diameter and wall thickness of the plastic tube meet the requirements for the desired product. This reduces the internal pressure of the adjustable-diameter plastic extruder by distributing the pressure externally through the expanding die. During replacement and maintenance, only the expanding die needs to be repaired or replaced. This solves the problem of reduced extruder lifespan and shortened maintenance cycles caused by prolonged high-pressure extrusion when producing thin-walled plastic tubes. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall plastic tube extrusion mold of this application.

[0018] Figure 2 This is a partial schematic diagram of the plastic tube extrusion die of this application. Figure 1 .

[0019] Figure 3 This is a partial exploded view of the plastic pipe extrusion die of this application.

[0020] Figure 4 This is a partial schematic diagram of the plastic tube extrusion die of this application. Figure 2 .

[0021] Figure 5 This is a partial schematic diagram of the plastic tube extrusion die of this application. Figure 3 .

[0022] Figure 6 This is a partial side view of the plastic pipe extrusion die of this application. Figure 1 .

[0023] Figure 7 This is a cross-sectional view (AA) of the plastic pipe extrusion die of this application.

[0024] Figure 8 This is a partial schematic diagram of the plastic tube extrusion die of this application. Figure 4 .

[0025] Figure 9 This is a partial side view of the plastic pipe extrusion die of this application. Figure 2 .

[0026] Figure 10 This is a cross-sectional view of the plastic tube extrusion die of this application.

[0027] In the figure: 10 plastic extruder with adjustable inner diameter, threaded rod 100, expansion die 200, connecting part 210, transition part 220, expansion part 230, expansion block 300, long bolt 310, auxiliary sleeve 400, connecting ring 410, extension sleeve 420, guide channel 500. Detailed Implementation

[0028] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0029] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," "top," "bottom," "end," "top," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0031] Please see Figures 1 to 10 This application provides a plastic pipe extrusion die, disposed at the end of the discharge port of a plastic extruder 10 with adjustable inner diameter, comprising: a diameter expansion die 200, the diameter expansion die 200 including a connecting part 210, a transition part 220 and a diameter expansion part 230, the connecting part 210 being detachably connected to the end of the discharge port of the plastic extruder 10 with adjustable inner diameter, and the axis of the connecting part 210 coinciding with the axis of the discharge port of the plastic extruder 10 with adjustable inner diameter, the transition part 220 being located at the end of the connecting part 210 away from the discharge port of the plastic extruder 10 with adjustable inner diameter, and the outer diameter of the transition part 220 being the same as the inner diameter of the discharge port of the plastic extruder 10 with adjustable inner diameter; the diameter expansion part 230 being located at the end of the transition part 220 away from the connecting part 210, the diameter expansion part being used to expand the inner diameter of the plastic pipe.

[0032] Specifically, the plastic extruder 10 with adjustable inner diameter adopts, but is not limited to, the plastic extruder 10 with adjustable inner diameter of extrusion tube disclosed in CN214111393U; a threaded rod 100 is provided on its axis (center line of the horizontal plane of the extrusion tube), and a groove is provided in the connecting part 210, with threads in the groove. By aligning the groove with the threaded rod 100 and rotating it, a detachable connection can be made; the connecting part 210, the transition part 220 and the expansion part 230 are all integrally formed steel; the outer diameter of the transition part 220 is the same as the inner diameter of the extrusion tube; the end of the expansion part 230 with a smaller outer diameter is close to the transition part 220.

[0033] Furthermore, when manufacturing the plastic tube (extrusion tube), the inner diameter of the plastic extruder 10 with adjustable inner diameter of the extrusion tube is adjusted so that its inner diameter is smaller than the inner diameter of the plastic tube to be manufactured, and its wall thickness is greater than the wall thickness of the plastic tube to be manufactured; the outer diameter of the rotating connecting part 210 is the same as the inner diameter of the discharge port of the plastic extruder 10 with adjustable inner diameter of the extrusion tube, and the maximum outer diameter of the expanding part 230 is the same as the inner diameter of the plastic tube to be manufactured by the expanding die 200; the connecting part 210 of the expanding die 200 is detachably connected to the threaded rod 100, and during installation, the measuring part is adjusted. Test whether the expansion mold 200 is coaxial with the plastic extruder 10 with adjustable inner diameter of the extrusion tube. After installation, turn on the plastic extruder 10 with adjustable inner diameter of the extrusion tube. The plastic tube is extruded from the discharge port of the plastic extruder 10 with adjustable inner diameter of the extrusion tube and moves along the connecting part 210 to the transition part 220. Then, with the change angle of the expansion part 230, the inner diameter of the plastic tube is expanded, and at the same time, its wall thickness is thinned with the change of diameter. When the plastic tube leaves the expansion part 230, the inner diameter and wall thickness of the plastic tube meet the requirements of the inner diameter and wall thickness of the plastic tube to be produced.

[0034] The technical solution of the plastic tube extrusion die adopted in this application can achieve the following beneficial effects:

[0035] By reducing the inner diameter of the adjustable-diameter plastic extruder 10, the wall thickness of the extruded material increases, thereby reducing the internal structural pressure of the adjustable-diameter plastic extruder 10. Then, by setting an expanding die 200, the inner diameter of the plastic tube is enlarged outside the adjustable-diameter plastic extruder 10, reducing the wall thickness, so that the inner diameter and wall thickness of the plastic tube meet the requirements of the desired plastic tube. This reduces the internal structural pressure of the adjustable-diameter plastic extruder 10, and the pressure is distributed externally through the expanding die 200. During replacement and maintenance, only the expanding die 200 needs to be repaired or replaced. This solves the problem that in the production of plastic tubes with small wall thicknesses, the extruder uses high pressure for extrusion, which, over a long period, leads to a reduced extruder lifespan and shorter maintenance cycles.

[0036] Based on the above solution, the plastic pipe extrusion die provided in this application further includes an auxiliary sleeve 400. The auxiliary sleeve 400 is sleeved on the expansion die 200 and is detachably connected to one end of the discharge port of the plastic extruder 10 with adjustable inner diameter. The axis of the auxiliary sleeve 400 coincides with the axis of the expansion die 200, and the inner diameter of the auxiliary sleeve 400 is the same as the outer diameter of the plastic pipe.

[0037] Furthermore, the inner diameter of the auxiliary sleeve 400 is the same as the outer diameter of the plastic tube to be manufactured. One end of the auxiliary sleeve 400 is provided with a connecting ring 410, which has several holes. The discharge end of the plastic extruder 10 with adjustable inner diameter of the extrusion tube is provided with a connecting hole corresponding to the hole. The auxiliary sleeve 400 is detachably connected to the connecting hole by means of bolts passing through the holes, thereby fixing the auxiliary sleeve 400 to the discharge end of the plastic extruder 10 with adjustable inner diameter of the extrusion tube. The axis of the auxiliary sleeve 400 coincides with the axis of the expanding die 200. A guide channel 500 is formed between the auxiliary sleeve 400 and the expanding die 200. When the plastic tube enters the guide channel 500 from the discharge end of the plastic extruder 10 with adjustable inner diameter of the extrusion tube, it changes diameter along the direction of the guide channel 500. The wall thickness of the plastic tube is squeezed by the expanding die 200 and the auxiliary sleeve 400 in the guide channel 500, thereby making its wall thickness meet the wall thickness requirements of the plastic tube to be manufactured. By setting an auxiliary sleeve 400, the problem of uneven and inaccurate control of wall thickness when the inner diameter of the plastic tube is increased under the action of the expansion mold 200 is solved.

[0038] In another embodiment of this application, the connecting portion 210 passes through the transition portion 220 and the expanding portion 230, and is threadedly engaged with the end of the discharge port of the plastic extruder 10 with adjustable inner diameter. The connecting portion 210 has a threaded through hole that passes through the transition portion 220 and the expanding portion 230. A long threaded rod 100 extends from the end of the discharge port of the plastic extruder 10 with adjustable inner diameter. The long threaded rod 100 passes through the threaded through hole to detachably connect the expanding die 200 to the end of the discharge port of the plastic extruder 10 with adjustable inner diameter; the operation is simple and convenient, and it is easy to install and disassemble.

[0039] In another embodiment of this application, an extension sleeve 420 is detachably provided at the end of the auxiliary sleeve 400 away from the discharge port of the plastic extruder 10 with adjustable inner diameter. The length of the extension sleeve 420 is flush with the end of the expansion section 230 away from the transition section 220. A plurality of expansion blocks 300 are detachably connected to the end of the expansion section 230 away from the transition section 220, and the outer diameters of the expansion blocks 300 increase sequentially in the direction away from the transition section 220. A plurality of extension sleeves 420 are provided, and adjacent extension sleeves 420 are detachably connected by connectors. The end of the extension sleeve 420 away from the auxiliary sleeve 400 is flush with the end of the expansion block 300, and the inner diameter of the extension sleeve 420 changes in the same way as the outer diameter of the expansion block 300.

[0040] Specifically, the shape of the expanding block 300 is similar to that of the expanding portion 230 of the expanding mold 200, and the minimum outer diameter of the expanding block 300 is the same as the maximum outer diameter of the expanding portion 230 of the expanding mold 200. By setting multiple expanding blocks 300, the inner diameter of the plastic tube is increased, thereby improving the applicability of the expanding mold 200 and enabling it to be used for the production of plastic tubes with different inner diameters. Similarly, the length of the extension sleeve 420 is the same as the length of the expanding block 300, and the inner diameter of the extension sleeve 420 also changes with the change of the outer diameter of the expanding block 300. Furthermore, the circumferential extension line of the inner diameter of the extension sleeve 420 is parallel to the circumferential extension line of the outer diameter of the expansion block 300 (different wall thicknesses can be adjusted by replacing different extension sleeves 420); two adjacent expansion blocks 300 are threadedly connected to the pre-reserved hole of the expansion mold 200 by long bolts 310 passing through the expansion block 300; two adjacent extension sleeves 420 are detachably connected by connectors; by increasing the number of extension sleeves 420 and expansion blocks 300, the inner diameter and wall thickness of the plastic tube can be adjusted, thereby making it more adaptable and easier to operate.

[0041] In the above scheme, the connecting component is a connecting flange. By setting flanges at both ends of the extension sleeve 420, the connection is simple and convenient. Alternatively, the connecting component can be a screw, with several through holes on the extension sleeve 420 and threaded holes on the auxiliary sleeve 400. The screw passes through the through holes and connects with the threaded holes.

[0042] Obviously, the embodiments described above are only some embodiments of this application, not all embodiments. The accompanying drawings show preferred embodiments of this application, but do not limit the patent scope of this application. This application can be implemented in many different forms; rather, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this application's specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the scope of patent protection of this application.

[0043] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A plastic pipe extrusion die, disposed at the end of the discharge port of a plastic extruder with an adjustable inner diameter, characterized in that, include: An expanding die includes a connecting part, a transition part, and an expanding part. The connecting part is detachably connected to the end of the discharge port of the plastic extruder with adjustable inner diameter, and the axis of the connecting part coincides with the axis of the discharge port of the plastic extruder with adjustable inner diameter. The transition part is located at the end of the connecting part away from the discharge port of the plastic extruder with adjustable inner diameter, and the outer diameter of the transition part is the same as the inner diameter of the discharge port of the plastic extruder with adjustable inner diameter. The expanding part is located at the end of the transition part away from the connecting part, and the expanding part is used to expand the inner diameter of the plastic tube.

2. The plastic pipe extrusion die as described in claim 1, characterized in that, It also includes an auxiliary sleeve, which is fitted onto the expansion die and is detachably connected to one end of the discharge port of the plastic extruder with adjustable inner diameter. The axis of the auxiliary sleeve coincides with the axis of the expansion die, and the inner diameter of the auxiliary sleeve is the same as the outer diameter of the plastic tube.

3. The plastic pipe extrusion die as described in claim 2, characterized in that, An extension sleeve is detachably provided at the end of the auxiliary sleeve away from the discharge port of the plastic extruder with adjustable inner diameter. The length of the extension sleeve is flush with the end of the expanded diameter portion away from the transition portion.

4. The plastic pipe extrusion die as described in claim 1, characterized in that, The connecting part passes through the transition part and the enlarged diameter part, and is threadedly engaged with the end of the discharge port of the plastic extruder with adjustable inner diameter.

5. The plastic pipe extrusion die as described in claim 3, characterized in that, The end of the diameter-expanding section away from the transition section is detachably connected to several diameter-expanding blocks, and the outer diameter of the several diameter-expanding blocks increases sequentially in the direction away from the transition section.

6. The plastic tube extrusion die as described in claim 5, characterized in that, Several extension sleeves are provided, and adjacent extension sleeves are detachably connected by a connector. The extension sleeve at the end away from the auxiliary sleeve is flush with one end of the expansion block, and the inner diameter of the extension sleeve changes in the same way as the outer diameter of the expansion block.

7. The plastic tube extrusion die as described in claim 6, characterized in that, The connecting component is a connecting flange.

8. The plastic tube extrusion die as described in claim 6, characterized in that, The connector is a screw, the extended sleeve is provided with several through holes, the auxiliary sleeve is provided with threaded holes, and the screw passes through the through holes and is connected to the threaded holes.

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