Internal spiral hollow wall pipe extrusion die

Abstract

The utility model discloses an extrusion die for an internal spiral hollow wall pipe. The extrusion die mainly solves the technical problem that an existing extrusion die cannot form a pipe hollow wall and an internal spiral flow guide flange so as to achieve the mute effect of the pipe. The hollow cavity die is relatively fixed at a machine head of an extruder, the mouth die is relatively fixed with the hollow cavity die and is used for forming the outer wall of a pipe, and the core die is coaxially arranged with the hollow cavity die and is used for forming the inner wall of the pipe; the hollow cavity die comprises a positioning ring and a plurality of hole dies which are arranged along the inner edge of the positioning ring in a circumferential array mode through connecting ribs and used for forming hollow cavities in the pipe wall of the pipe, air inlet holes are formed in the positions, corresponding to the hole dies, of the outer edge of the positioning ring respectively, and air blowing holes communicated with the corresponding air inlet holes are formed in the ends of the hole dies respectively; the outer edge of the core mold is correspondingly provided with a material groove with the section matched with the section of the inner spiral flange to be formed. Therefore, the inner spiral hollow wall pipe can be extruded and molded, and a good drainage mute effect is achieved through the hollow cavity and the spiral flange.

Description

Technical Field

[0001] This application relates to the field of water supply and drainage technology, specifically to an extrusion die for an internally spiral hollow wall pipe. Background Technology

[0002] Silent drainage pipes are a type of piping system specifically designed to reduce noise generated during water flow and drainage. They are widely used in places where a quiet environment is required, such as buildings, residences, hotels, hospitals, and office buildings. Silent drainage pipes utilize special materials and designs, such as hollow walls and special sound-absorbing materials, to reduce the noise generated when water flows through the pipes.

[0003] Pipe production requires extrusion molding, and extruders typically consist of components such as a screw, barrel, die head, mandrel, and die. The screw is responsible for conveying, compressing, melting, and mixing the plastic granules; the barrel is equipped with a heating device to load the plastic granules, working closely with the screw, and heats the granules to a molten state via resistance wire heating or electromagnetic heating; the die head is the key part of the extrusion mold, responsible for plasticizing and distributing the molten plastic, ensuring it enters the forming section evenly; the mandrel is located inside the die head and forms the inner wall of the pipe; the die is the exit part of the extrusion mold, used to control the outer diameter and shape of the pipe, and the die material is generally the same as the die head, possessing high hardness and precision.

[0004] However, in the process of implementing the technical solutions in the embodiments of this application, the inventors of this application discovered that the molds corresponding to the existing pipe extruders can only achieve the extrusion molding of ordinary pipes, and cannot form a hollow cavity in the pipe wall and it is difficult to form an inner spiral flange on the inner edge of the pipe wall to reduce drainage noise.

[0005] The information disclosed in this background section is intended only to enhance the understanding of the background technology of this disclosure and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] In view of at least one of the above technical problems, this disclosure provides an internal spiral hollow wall pipe extrusion die, which mainly solves the technical problem that existing extrusion dies cannot form the hollow wall of the pipe and the internal spiral flow guide flange, thereby achieving the pipe's noise reduction effect.

[0007] According to one aspect of this disclosure, an extrusion die for an internally spiral hollow-walled pipe is provided, comprising a hollow cavity die fixed relative to the extruder die head, an orifice die fixed relative to the hollow cavity die for forming the outer wall of the pipe, and a core die coaxially disposed with the hollow cavity die for forming the inner wall of the pipe; the hollow cavity die includes a positioning ring and a plurality of orifice dies arranged circumferentially along the inner edge of the positioning ring by a connecting rib array for forming the hollow cavity of the pipe wall, wherein the outer edge of the positioning ring is provided with an air inlet corresponding to each orifice die, and each orifice die end is provided with an air blowing hole communicating with the corresponding air inlet; the outer edge of the core die is provided with a material groove whose cross-section matches the cross-section of the inner spiral flange to be formed.

[0008] In some embodiments of this disclosure, the die end is provided with a cavity groove that matches the hollow cavity die, and the hollow cavity die is fixed to the extruder head via the die.

[0009] In some embodiments of this disclosure, the core mold is connected to a drive mechanism for driving the core mold to rotate.

[0010] In some embodiments of this disclosure, the cross-section of the die is correspondingly serrated.

[0011] In some embodiments of this disclosure, the blowhole is provided at the edge end of each tooth surface of the serrated cross section of the die.

[0012] In some embodiments of this disclosure, each of the air holes in the mold is connected to the other, and the connecting rib is provided with an air passage that is connected to the air hole and the air inlet respectively.

[0013] In some embodiments of this disclosure, the connecting rib is fixed at the middle position of the corresponding end side of the die, and the thickness of the connecting rib is less than 2 mm.

[0014] One or more technical solutions provided in the embodiments of this disclosure have at least one of the following technical effects or advantages:

[0015] 1. By using a hollow cavity mold coaxially positioned at the gap between the core mold and the die, the hollow cavity in the pipe wall can be formed, thereby improving the noise reduction effect of the pipe.

[0016] 2. The air blowing holes at each hole of the hollow cavity mold can blow pressurized gas along the output direction of the pipe during the pipe extrusion molding process, thereby avoiding the material fusion at the tail of the hollow cavity mold and ensuring the forming effect of the hollow cavity in the pipe wall.

[0017] 3. A material groove is provided at the end of the core mold to form a flange of corresponding shape on the inner edge surface of the tube. Through the drive mechanism connected to the core mold, the core mold can be rotated uniformly along the axis, so that the position of the material groove changes along the circumference, thereby forming an inner spiral flange. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the cavity mold and core mold fitting together in one embodiment of this application.

[0019] In the above figures, 1 is the hollow cavity mold, 11 is the positioning ring, 12 is the hole mold, 13 is the air blowing hole, 14 is the air inlet hole, 2 is the core mold, and 21 is the material groove. Detailed Implementation

[0020] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inner", "outer", "vertical", "horizontal", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0021] To better understand the technical solution of this application, the above technical solution will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] To achieve the forming of hollow walls and inner spiral flanges in pipes, thereby achieving the effect of quiet drainage, this example discloses an extrusion die for inner spiral hollow wall pipes, which includes a hollow cavity die for forming the hollow cavity of the pipe wall, an orifice die for forming the outer wall of the pipe, and a core die for forming the inner wall and inner spiral flange of the pipe.

[0023] The die body is a hollow cylindrical structure. The inner diameter of this hollow cylinder matches the designed outer diameter of the pipe. By confining the injection molding material through the hollow cylinder, the outer wall of the pipe is formed. In this example, one end of the die is provided with a connecting flange, and the extruder head is provided with a flange seat that matches the connecting flange. Thus, the die can be reliably connected to the extruder head through the flange. After the material output from the extruder comes into contact with the smooth inner wall of the die, it forms the outer wall of the pipe that matches the inner diameter of the die.

[0024] In order to form a hollow cavity in the pipe wall to improve the sound insulation effect of the pipe, in this embodiment, see... Figure 1A hollow cavity mold 1 is fixedly installed at the extruder die head. In this example, the hollow cavity mold 1 includes a positioning ring 11 and several orifice molds 12 for forming hollow cavities in the pipe wall. The positioning ring 11 is used to fix the relative positions of each orifice mold 12 so that a hollow cavity is formed in the pipe wall during the material extrusion process. On the other hand, the positioning ring 11 is also used to fix the hollow cavity mold 1. Specifically, in this example, the end of the die with a connecting flange has an annular shoulder that matches the positioning ring 11 and forms a cavity. The height of the annular shoulder matches the thickness of the positioning ring 11, and the diameter of the annular shoulder also matches the diameter of the positioning ring 11. This allows the positioning ring 11, i.e., the hollow cavity mold 1, to be embedded in the end of the die. When the die is fixedly connected to the flange seat at the extruder die head through the connecting flange, the end face of the positioning ring of the hollow cavity mold 1 is in contact with the end face of the extruder die head. Thus, the hollow cavity mold 1 is fixed at the same time as the die. In this embodiment, the center of the annular shoulder at the end of the die passes through the central axis of the die, thereby enabling the hollow cavity die 1 embedded at the end of the die to be coaxially arranged with the die. In addition, the positioning ring 11 positions each hole die 12, so that each hole die 12 accurately forms a hollow cavity corresponding to the pipe wall.

[0025] In this embodiment, the perforated molds 12 of the hollow cavity mold 1 are arranged in a circumferential array along the inner edge of the positioning ring, thereby correspondingly forming the hollow cavities circumferentially distributed in the tube wall. For details, see [link to documentation]. Figure 1 In this example, the cross-section of the stencil 12 is serrated, thereby forming serrated hollow cavities at the pipe wall. This causes the sound waves to be continuously reflected within the serrated hollow cavities, increasing the sound wave reflection path and thus achieving the technical effect of weakening the sound wave energy and reducing drainage noise.

[0026] In this example, the wall of the hollow cavity near the center of the pipe is considered the inner wall, and the wall of the hollow cavity near the outer side of the pipe is considered the outer wall. Considering that the outer wall has a certain thickness, and that the outer wall is mainly formed through the gap between the inner edge of the positioning ring 11 and the die 12, it is not possible to directly fix each die 12 to the inner ring of the positioning ring 11. Otherwise, it would lead to the hollow cavity being exposed at the outer wall of the pipe or the outer wall not being able to be sealed. Therefore, in this embodiment, a connecting rib is used to connect the die 12 to the inner edge of the positioning ring 11. The connecting rib is fixed at the middle position of one side of the die 12, thereby ensuring the stability of the die under force. In addition, considering that the connecting rib must have a certain thickness, and that the connecting rib is located in the forming gap of the outer wall, to avoid the connecting rib from having an adverse effect on the forming of the outer wall, the thickness of the connecting rib is limited to less than 2 mm, and its length along the axial direction of the hollow cavity die is less than the thickness of the positioning ring 11. This allows the material extruded by the extruder to fuse again after passing through the connecting rib, thereby forming a closed outer wall.

[0027] However, there is a risk that the material after passing through the die 12 may re-fuse, which could prevent the hollow cavity at the pipe wall from being formed. Therefore, in this embodiment, see... Figure 1 Air holes 13 are provided at the ends of each die 12 furthest from the positioning ring 11. The air blown out through the air holes 13 prevents the material separated by the die 12 from re-merging, thereby ensuring the formation of a hollow cavity in the pipe wall. In addition, in this example, in order to ensure that the hollow cavity is serrated, air holes 13 are provided at the ends of the edges corresponding to the teeth of each serrated die. In some other embodiments, the cross-section of each air hole 13 is rectangular to ensure the effective forming of the serrated hollow cavity.

[0028] To achieve air supply to each air inlet 13, see the following in this embodiment: Figure 1 The outer edge of the positioning ring 11 is provided with air inlets 14 at the positions corresponding to the positions of each die 12. The air inlets 14 are connected to the connecting ribs on the inner edge surface of the positioning ring 11, and the connecting ribs are provided with air passages connected to them. The other end of the air passages is connected to the blowing holes 13 of each die. In this example, the blowing holes 13 at the die 12 are arranged in parallel, and one end of them is connected to the air passages of the connecting ribs, thereby forming an air flow channel between the air inlets 14 and the corresponding blowing holes 13.

[0029] Furthermore, in this embodiment, an annular air inlet groove is provided on the inner edge of the die corresponding to the position of each air inlet hole 14 of the hollow cavity die, and an air source interface connected to the air inlet groove is provided on the outer edge of the die. Thus, by connecting the air source interface to the air source, high-pressure gas enters the annular air inlet groove through the air source interface, and is then blown out through each air inlet hole 14 corresponding to each air blowing hole 13, thereby realizing the formation of the hollow cavity in the tube wall.

[0030] To achieve the forming of the inner edge of the pipe, in this embodiment, the extrusion die also includes a core mold, see [link to documentation]. Figure 1 The core mold 2 is a variable diameter structure, coaxially arranged with the hollow cavity mold and the die. Its end, passing through the hollow cavity mold, is used to form the inner wall of the pipe, and the outer diameter of this end matches the designed inner diameter of the pipe. Thus, through the combined action of the internal core mold 2 and the external die, an injection cavity is formed between them, thereby forming the pipe wall. The hollow wall is formed by the hollow cavity mold fixed between them. To form an inner spiral flange on the inner wall of the pipe, causing the water flowing through the pipe to form a swirling flow, thereby reducing potential energy and thus reducing noise, in this embodiment, see... Figure 1 A material groove 21 is provided at the outer edge of the end of the core mold 2. The cross section of the material groove matches the cross section of the inner spiral flange to be formed. The other end of the core mold 2 is connected to a drive mechanism. Under the drive of the drive mechanism, the core mold 2 rotates at a constant speed along its central axis, so that the material extruded from the material groove 21 forms the spiral flange on the inner wall of the tube.

[0031] Although some preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0032] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of its inventive concept. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A spiral hollow-walled tube extrusion die, characterized in that, The device includes a hollow cavity mold fixed to the extruder head, an orifice mold fixed to the hollow cavity mold for forming the outer wall of the pipe, and a core mold coaxially arranged with the hollow cavity mold for forming the inner wall of the pipe. The hollow cavity mold includes a positioning ring and a plurality of orifice molds arranged circumferentially along the inner edge of the positioning ring via connecting ribs for forming the hollow cavity of the pipe wall. The outer edge of the positioning ring is provided with air inlets corresponding to each orifice mold, and each orifice mold end is provided with an air blowing hole connected to the corresponding air inlet. The outer edge of the core mold is provided with a material groove whose cross-section matches the cross-section of the inner spiral flange to be formed.

2. The internal spiral hollow wall tube extrusion die according to claim 1, characterized in that, The die has a cavity groove at the corresponding end that matches the hollow cavity die, and the hollow cavity die is fixed to the extruder head by means of the die.

3. The internal spiral hollow wall tube extrusion die according to claim 1, characterized in that, The core mold is connected to a corresponding drive mechanism for driving the core mold to rotate.

4. The internal spiral hollow wall tube extrusion die according to claim 1, characterized in that, The cross-section of the die is serrated.

5. The internal spiral hollow wall tube extrusion die according to claim 1, characterized in that, The mold is provided with air holes at the edges of each tooth face corresponding to the sawtooth cross-section.

6. The internal spiral hollow wall tube extrusion die according to claim 5, characterized in that, Each of the air holes in the mold is connected to the corresponding air holes, and the connecting rib is provided with an air passage that is connected to the air holes and the air inlet holes respectively.

7. The internal spiral hollow wall tube extrusion die according to claim 1, characterized in that, The connecting rib is fixed at the middle position of the corresponding end side of the die, and the thickness of the connecting rib is less than 2mm.

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