PE double-layer pipe body and production process

Abstract

The invention discloses a PE double-layer pipe body and a production process, and belongs to the PE pipe technology, the PE double-layer pipe body comprises an inner-layer pipe body and an outer-layer pipe body, the inner-layer pipe body comprises a first guide part and a second guide part, and the first guide part and the second guide part are arranged on the same circumferential surface of the outer wall of the inner-layer pipe body; the outer-layer pipe body comprises a first guide part, a second guide part, a first connecting part and a second connecting part, the first guide part, the second guide part, the first connecting part and the second connecting part are arranged on the inner wall of the outer-layer pipe body, and the first guide part and the second guide part are arranged in the length direction of the outer-layer pipe body; and the first connecting part and the second connecting part are arranged on the same circumferential surface of the inner wall of the outer-layer pipe body. The PE double-layer pipe body provided by the invention is simple in structure, simple and efficient in connection mode and high in stability; meanwhile, the production process is simple, and the production efficiency can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of PE pipes, and particularly relates to a PE double-layer pipe body and a production process. Background Art

[0002] A PE pipe body is a polyethylene pipe, which is a plastic pipe with characteristics such as corrosion resistance, impact resistance, and long service life. It is widely used in various aspects of production and life. In order to meet the requirements of different conveying media or laying environments, the existing PE pipe bodies are generally divided into single-layer pipe bodies and double-layer pipe bodies. The production of double-layer pipe bodies is generally carried out by extrusion using a double-layer co-extrusion extruder. The double-layer co-extrusion extruder consists of several parts such as an extruder main body, a conveying device, a die head, a cooling water tank, a cutting device, and an automatic control system. The entire device can synchronously extrude two different materials.

[0003] However, the double-layer pipe bodies produced by double-layer co-extrusion in the current technology have the following defects: when extruded, the inner and outer pipe bodies are generally in a non-cured state, that is, the inner and outer pipe bodies have a certain deformation ability, which makes the overall connection of the inner and outer pipe bodies extremely unstable after curing. When connecting multiple pipe bodies, it is impossible to connect quickly and stably. Summary of the Invention

[0004] The purpose of the present invention is to solve some problems existing in the prior art, and a PE double-layer pipe body and a production process are proposed to achieve quick and stable connection when connecting multiple pipe bodies.

[0005] To achieve the above purpose, the technical solution of the present invention is as follows: A PE double-layer pipe body includes: An inner layer pipe body, the inner layer pipe body includes a first guiding member and a second guiding member, and the first guiding member and the second guiding member are arranged on the same circumferential surface of the outer wall of the inner layer pipe body; An outer layer pipe body, the outer layer pipe body is arranged outside the inner layer pipe body. The outer layer pipe body includes a first guiding portion and a second guiding portion. The first guiding portion and the second guiding portion are respectively adapted to the first guiding member and the second guiding member. The first guiding portion and the second guiding portion are arranged on the inner wall of the outer layer pipe body, and the first guiding portion and the second guiding portion are arranged along the length direction of the outer layer pipe body; The outer layer pipe body further includes a first connecting portion and a second connecting portion. The first connecting portion and the second connecting portion are respectively adapted to the first guiding member and the second guiding member. The first connecting portion and the second connecting portion are arranged on the inner wall of the outer layer pipe body, and the first connecting portion and the second connecting portion are respectively communicated with the first guiding portion and the second guiding portion. The first connecting portion and the second connecting portion are arranged on the same circumferential surface of the outer layer pipe body.

[0006] On the basis of the above solution, a first guide member inclined surface and a second guide member inclined surface are respectively provided on the first guide member and the second guide member; a first guide portion inclined surface and a second guide portion inclined surface are respectively provided on the first guide portion and the second guide portion, and the first guide portion inclined surface and the second guide portion inclined surface are respectively adapted to the first guide member inclined surface and the second guide member inclined surface.

[0007] Based on the above technical means: The adapted guide portion inclined surface and the guide member inclined surface can effectively improve the assembly efficiency of the inner tube body and the outer tube body.

[0008] On the basis of the above solution, the first guide member and the second guide member are spaced apart, and the first connecting portion and the second connecting portion are spaced apart.

[0009] Based on the above technical means: The spaced-apart first guide member and second guide member and the spaced-apart first connecting portion and second connecting portion ensure that when the first guide member and the second guide member move along the first connecting portion and the second connecting portion, the second guide member will not enter the first connecting portion, and the first guide member will not enter the second connecting portion, thereby preventing interference with the movement of the first guide member or the second guide member, and improving the assembly efficiency of the inner tube body and the outer tube body.

[0010] On the basis of the above solution, the number of the first guide members is equal to the number of the first connecting portions, and the number of the second guide members is equal to the number of the second connecting portions.

[0011] Based on the above technical means: Since the number of the first guide members is equal to the number of the first connecting portions, and the number of the second guide members is equal to the number of the second connecting portions, the first guide members and the first connecting portions, and the second guide members and the second connecting portions can be in one-to-one correspondence, improving the connection accuracy.

[0012] On the basis of the above solution, a gap is left between the inner tube body and the outer tube body.

[0013] Based on the above technical means: When the first guide member and the second guide member rotate into the first connecting portion and the second connecting portion and are fixedly connected, a gap is formed between the inner tube body and the outer tube body. When the inner tube body circulates a heat medium or other media, the gap can play roles such as heat insulation and oxygen isolation, improving the heat insulation, oxygen isolation and other effects of the PE double-layer tube body.

[0014] A production process of a PE double-layer tube body includes the following steps: S1: Flow molten polyethylene into a forming device respectively, let it stand and cool to obtain an inner tube body and an outer tube body in a solid state respectively. A plurality of first guiding members and a plurality of second guiding members are formed on the outer wall of the inner tube body, and a plurality of first guiding portions, a plurality of second guiding portions, a plurality of first connecting portions and a plurality of second connecting portions are formed on the inner wall of the outer tube body; S2: Align the first guiding member and the second guiding member with the first guiding portion and the second guiding portion respectively, and then insert one end of the inner tube body into the interior of the outer tube body; S3: Drive the inner tube body to move inside the outer tube body, and drive the outer tube body or the inner tube body to rotate circumferentially along the outer tube body or the inner tube body at a suitable position according to the actual situation, so that the first guiding member and the second guiding member are gradually connected to the first connecting portion and the second connecting portion respectively, so that the outer tube body and the inner tube body are stably connected, and plugs and sockets are formed at both ends; S4: Inject a foaming agent between the interlayers of the connected inner tube body and outer tube body, let it stand and cure to obtain a PE double-layer tube body; S5: Align the first guiding member and the second guiding member of one section of the PE double-layer tube body with the first guiding portion and the second guiding portion of another section of the PE double-layer tube body, and insert the plug of one section of the PE double-layer tube body into the socket of another section of the PE double-layer tube body until one section of the PE double-layer tube body abuts against another section of the PE double-layer tube body; S6: Drive one section of the PE double-layer tube body to rotate circumferentially along another section of the PE double-layer tube body, so that the first guiding member and the second guiding member of one section of the PE double-layer tube body are gradually connected to the first connecting portion and the second connecting portion of another section of the PE double-layer tube body respectively, so that the two sections of the PE double-layer tube body are stably connected; S7: Treat the connection part of the inner tube bodies of the two sections of the PE double-layer tube body at a temperature of 120°C - 125°C, so that the first guiding member and the second guiding member of one section of the PE double-layer tube body are in a molten state inside the first connecting portion and the second connecting portion of another section of the PE double-layer tube body, and let it stand and cool to fix the connection of the inner tube bodies of the two sections of the PE double-layer tube body; S8: Add a connecting member at the connection part of the outer tube bodies of the two sections of the PE double-layer tube body, and treat the connection part of the connecting member and the outer tube bodies of the two sections of the PE double-layer tube body at a temperature of 120°C - 140°C, so that the connection part is in a molten state; S9: Let it stand and cool to obtain a tube body after connecting multiple sections of the PE double-layer tube body.

[0015] On the basis of the above solution, further, one end of the PE double-layer tube body formed in step S4 is closed with a cap; Align the position where the foaming agent is injected with the first guiding portion and the second guiding portion, and inject the foaming agent along the extending direction of the first guiding portion and the second guiding portion.

[0016] Based on the above technical means: One end of the PE double-layer pipe body is closed with a cap to form a closed cavity, preventing the leakage of the foaming agent, ensuring stable foaming pressure, and enabling the foaming agent to fully fill the interlayer between the inner pipe body and the outer pipe body.

[0017] On the basis of the above solution, the cap is provided with an observation part, and the observation part is used to monitor the filling degree of the foaming agent at the other end in the interlayer of the PE double-layer pipe body when injecting the foaming agent.

[0018] Based on the above technical means: By integrating the observation part on the cap, visual monitoring and precise control of the foaming agent filling process are realized.

[0019] On the basis of the above solution, in the PE double-layer pipe body formed in step S4; Align the position where the foaming agent is filled with both ends of the first guiding part and the second guiding part, and inject the foaming agent simultaneously along both ends of the first guiding part and the second guiding part; When the foaming agent overflows at both ends of the PE double-layer pipe body, stop injecting.

[0020] Based on the above technical means: By injecting the foaming agent simultaneously from both ends of the first guiding part and the second guiding part of the PE double-layer pipe body, the foaming agent diffuses evenly along the interlayer between the inner pipe body and the outer pipe body, reducing problems such as local bubble aggregation or incomplete filling caused by unilateral injection.

[0021] On the basis of the above solution, the foaming agent includes polyurethane prepolymer.

[0022] Based on the above technical means: The foaming agent contains polyurethane prepolymer, which forms a tight bond with the PE pipe wall during the curing process, avoiding the problem of easy delamination of traditional physical foaming agents, and ensuring the interfacial bonding strength between the foaming layer and the inner and outer pipe bodies; the polyurethane foaming layer has excellent compressive strength and low density, effectively buffering external impact loads while ensuring the overall light weight of the pipe body; the polyurethane closed-cell structure significantly reduces the thermal conductivity coefficient and can effectively adapt to environments where low-temperature fluids are transported or temperature stability is required.

[0023] Compared with the prior art, the present invention has the following beneficial effects: 1. The PE double-layer tube body provided by the present invention is respectively provided with a first guiding member and a second guiding member on the inner-layer tube body, and a first guiding portion and a second guiding portion on the outer-layer tube body. When the inner-layer tube body is driven to penetrate into the inner part of the outer-layer tube body during the connection of the inner and outer tube bodies, the first guiding member moves along the first guiding portion; the outer-layer tube body is also provided with a first connecting portion and a second connecting portion. When the first guiding member moves to the first position, the outer-layer tube body rotates relative to the inner-layer tube body, so that the first guiding member and the second guiding member respectively rotate into the first connecting portion and the second connecting portion, thereby realizing the fixed connection of the inner and outer tube bodies. The PE double-layer tube body formed in the above way has a simple and efficient connection method and strong stability; at the same time, since the first guiding member and the second guiding member are arranged on the same circumferential surface of the outer wall of the inner-layer tube body, when the inner and outer layer tube bodies are connected, the first guiding member and the second guiding member can be driven to rotate into the first connecting portion and the second connecting portion together after the inner-layer tube body moves to the fixed position, eliminating the interference during the connection of the first guiding member, the second guiding member and the first connecting portion, the second connecting portion, improving the efficiency during assembly, and enhancing the stability of the connection between the inner and outer tube bodies.

[0024] 2. The production process of the PE double-layer tube body provided by the present invention forms a phased guiding mechanism by setting a first guiding member and a second guiding member on the outer wall of the inner-layer tube body and correspondingly setting a first connecting portion and a second connecting portion on the inner wall of the outer-layer tube body, ensuring that the inner-layer tube body can be axially inserted into the outer-layer tube body quickly and accurately, avoiding deflection or jamming, and realizing the circumferential fixation of the inner and outer layer tube bodies by rotating to connect the guiding member and the connecting portion, preventing relative displacement during subsequent foaming or use. This design significantly improves the assembly efficiency and at the same time reduces the difficulty of manual adjustment; different plugs and sockets can be configured according to actual needs, facilitating the seamless butt welding of subsequent multi-segment tube bodies; independent connecting pieces are used to weld two sections of the outer-layer tube body, which not only makes up for the defect that the foaming layer cannot be directly welded, but also forms an integral structure by hot melting, enhancing the impact resistance; this connection method solves the problems of poor sealing and insufficient durability caused by the traditional connection of PE tube bodies relying on adhesives or mechanical clamps. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a perspective view of the PE double-layer tube body of the present invention; Figure 2 is a perspective view of the inner-layer tube body of the present invention; Figure 3 is a perspective view of the outer-layer tube body of the present invention; Figure 4 is a perspective view of the connection of multi-segment PE double-layer tube bodies of the present invention; Figure 5 is a front view of the PE double-layer tube body of the present invention; Figure 6 is a schematic flow chart of the production method of the PE double-layer tube body of the present invention.

[0026] Reference numerals: 1. Inner tube body, 11. First guide member, 12. Second guide member, 13. First guide member inclined surface, 14. Second guide member inclined surface; 2. Outer tube body, 21. First guide portion, 22. Second guide portion, 23. First connection portion, 24. Second connection portion, 25. First guide portion inclined surface, 26. Second guide portion inclined surface; 3. Plug; 4. Socket. Detailed implementation manners

[0027] Here, exemplary embodiments will be described in detail, and examples thereof are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present application. On the contrary, they are merely examples of devices consistent with some aspects of the present application as detailed in the appended claims.

[0028] The terms used in the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. Unless otherwise defined, the technical terms or scientific terms used in the present application should be the ordinary meanings understood by those of ordinary skill in the art to which the present invention pertains. The terms "a" or "an" and the like used in the specification and claims of the present application do not also represent a limitation in quantity but mean that there is at least one. "Plurality" includes two, which is equivalent to at least two. The terms "comprising" or "including" and the like mean that the elements or items appearing before "comprising" or "including" cover the elements or items listed after "comprising" or "including" and their equivalents, and do not exclude other elements or items. The terms "connected" or "coupled" and the like are not limited to physical or mechanical connections and may include electrical connections, whether direct or indirect. The singular forms "a", "the" and "said" used in the specification and appended claims of the present application are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0029] As Figures 1-5As shown in the figure, one aspect of the present application provides a PE double-layer pipe body, which includes: an inner layer pipe body 1, the inner layer pipe body 1 includes a first guide member 11 and a second guide member 12, and the first guide member 11 and the second guide member 12 are arranged on the same circumferential surface of the outer wall of the inner layer pipe body 1; it further includes: an outer layer pipe body 2, the outer layer pipe body 2 is arranged outside the inner layer pipe body 1, the outer layer pipe body 2 includes a first guide portion 21 and a second guide portion 22, the first guide portion 21 and the second guide portion 22 are respectively adapted to the first guide member 11 and the second guide member 12, the first guide portion 21 and the second guide portion 22 are arranged on the inner wall of the outer layer pipe body 2, and the first guide portion 21 and the second guide portion 22 are arranged on the same circumferential surface of the outer layer pipe body 2.

[0030] According to this embodiment of the present invention, the first guide member 11 and the second guide member 12 are bumps fixedly arranged on the inner layer pipe body 1, the first guide portion 21 and the second guide portion 22 are grooves opened on the inner wall of the outer layer pipe body 2, and the bumps can move in the grooves to play a role in limiting and guiding.

[0031] In other embodiments of the present invention, the first guide member 11 and the second guide member 12 can also be slide rails, or other guiding structures detachably arranged on the inner layer pipe body 1, and no specific limitation is made here; the first guide portion 21 and the second guide portion 22 can also be chutes, or other connecting structures detachably arranged on the outer layer pipe body 2, and no specific limitation is made here. Those skilled in the art should understand that the specific shapes and structures of the first guide member 11 and the second guide member 12, and the first guide portion 21 and the second guide portion 22 are not limitations of the present invention.

[0032] It can be understood that the first guide member 11 and the second guide member 12 are arranged on the same circumferential surface of the outer wall of the inner layer pipe body 1, that is, the first guide member 11 and the second guide member 12 are arranged on the same circumferential surface perpendicular to the central axis of the inner layer pipe body 1.

[0033] Furthermore, the diameter of the inner layer pipe body 1 is smaller than the diameter of the outer layer pipe body 2, so that the inner layer pipe body 1 can penetrate into the inside of the outer layer pipe body 2. Further, the diameter of the inner layer pipe body 1 is smaller than the inner diameter of the outer layer pipe body 2, so that the inner layer pipe body 1 is more convenient to penetrate into the inside of the outer layer pipe body 2.

[0034] Furthermore, both the inner layer pipe body 1 and the outer layer pipe body 2 are made of polyethylene material. The melting point temperatures of the polyethylene materials used for the inner layer pipe body 1 and the outer layer pipe can be the same or different according to the specific use environment of the PE pipe body, and no specific limitation is made here.

[0035] Meanwhile, the outer tube body 2 further includes a first connection portion 23 and a second connection portion 24. The first connection portion 23 and the second connection portion 24 are respectively adapted to the first guide member 11 and the second guide member 12. The first connection portion 23 and the second connection portion 24 are provided on the inner wall of the outer tube body 2, and the first connection portion 23 and the second connection portion 24 are respectively communicated with the first guide portion 21 and the second guide portion 22. The first connection portion 23 and the second connection portion 24 are arranged along the same circumferential direction of the outer tube body 2.

[0036] According to this embodiment of the present invention, the first connection portion 23 and the second connection portion 24 are grooves formed on the inner wall of the outer tube body 2, and at least one end of the first connection portion 23 and the second connection portion 24 is communicated with the first guide portion 21 and the second guide portion 22, so as to facilitate the first guide member 11 and the second guide member 12 to enter the first connection portion 23 and the second connection portion 24 from the first guide portion 21 and the second guide portion 22.

[0037] In other embodiments of the present invention, the first connection portion 23 and the second connection portion 24 may also be chutes, or other connection structures detachably provided on the outer tube body 2, and no specific limitation is made here. Those skilled in the art should understand that the specific shapes and structures of the first connection portion 23 and the second connection portion 24 are not limitations of the present invention.

[0038] It is worth mentioning that the provided PE double-layer tube body is respectively provided with a first guide member 11 and a second guide member 12 on the inner tube body 1, and a first guide portion 21, a second guide portion 22, a first connection portion 23 and a second connection portion 24 on the outer tube body 2. When the inner and outer tube bodies are connected, the inner tube body 1 is driven to penetrate into the inner part of the outer tube body 2, and the first guide member 11 and the second guide member 12 respectively move along the first guide portion 21 and the second guide portion 22. When the first guide member 11 and the second guide member 12 move to a certain position (it can be a position where any one of the first guide member 11 and the second guide member 12 is aligned with the first connection portion 23 and the second connection portion 24), the outer tube body 2 rotates relative to the outer tube body 2, so that the first guide member 11 and the second guide member 12 rotate into the first connection portion 23 and the second connection portion 24, and the first guide member 11, the second guide member 12 are connected to the first connection portion 23 and the second connection portion 24, thereby realizing the fixed connection of the inner and outer tube bodies. The PE double-layer tube body formed in the above manner has a simple and efficient connection method and strong stability.

[0039] It is worth mentioning that since the first guiding member 11 and the second guiding member 12 are arranged on the same circumferential surface of the outer wall of the inner layer tube body 1, and the first connecting portion 23 and the second connecting portion 24 are arranged on the same circumferential surface of the inner wall of the outer layer tube body 2, when the inner and outer layer tube bodies 2 are connected, after the first guiding member 11 and the second guiding member 12 move to the fixed position together within the inner layer tube body 1, they are respectively driven to rotate into the first connecting portion 23 and the second connecting portion 24, reducing the interference between the first guiding member 11 and the second guiding member 12 or between the second guiding member 12 and the first guiding member 11 during rotation, and improving the efficiency during assembly; at the same time, since the first guiding member 11 and the second guiding member 12 can respectively rotate into the first connecting portion 23 and the second connecting portion 24, with double cooperation for fixation, the connection stability between the inner layer tube body 1 and the outer layer tube body 2 is further enhanced.

[0040] Please refer specifically to Figure 2 , on both sides of the first guiding member 11 and the second guiding member 12, there are respectively arranged a first guiding member inclined surface 13 and a second guiding member inclined surface 14; on both sides of the first guiding portion 21 and the second guiding portion 22, there are respectively arranged a first guiding portion inclined surface 25 and a second guiding portion inclined surface 26. The first guiding portion inclined surface 25 and the second guiding portion inclined surface 26 are respectively adapted to the first guiding member inclined surface 13 and the second guiding member inclined surface 14. The adaptation between the guiding member inclined surface and the guiding portion inclined surface plays a guiding role. The inclination angle of the inclined surface can enable the first guiding member 11 and the second guiding member 12 to generate a component force perpendicular to the inclined surface during movement, reducing the direct contact friction with the side wall, and compared with right-angle fitting, the inclined surface allows a larger assembly tolerance, reducing the assembly difficulty.

[0041] Furthermore, communication portions are respectively formed at the communication positions of the first guiding portion 21 and the first connecting portion 23, and the second guiding portion 22 and the second connecting portion 24, so as to allow the first guiding member 11 or the second guiding member 12 to pass through. When the first guiding portion 21, the first connecting portion 23, the second guiding portion 22, and the second connecting portion 24 are grooves or chutes, the communication portion is the position where the grooves or chutes intersect. When the inner layer tube body 1 and the outer layer tube body 2 are connected, after the first guiding member 11 and the second guiding member 12 move to the fixed position along the first guiding portion 21 and the second guiding portion 22, they can be directly driven to rotate into the first connecting portion 23 and the second connecting portion 24 from the communication portion, making the assembly efficiency higher.

[0042] Furthermore, the first guiding portion 21, the second guiding portion 22, the first connecting portion 23, and the second connecting portion 24 are all grooves, and the depth of the first guiding portion 21 is less than or equal to the depth of the first connecting portion 23, and the depth of the second guiding portion 22 is less than or equal to the depth of the second connecting portion 24. The guiding member can move along the guiding portion and can rotate along the connecting portion, improving the accuracy of assembly; the depth of the first guiding portion 21 is less than or equal to the depth of the first connecting portion 23, and the depth of the second guiding portion 22 is less than or equal to the depth of the second connecting portion 24, so that when the guiding member moves along the guiding portion to the communicating portion, without applying an external force, the sliding groove can more stably limit the movement of the guiding member, and further, when the guiding member is driven to rotate into the connecting portion, the connection between the guiding member and the connecting portion is more stable and reliable.

[0043] According to this embodiment of the present invention, the first guiding member 11 and the second guiding member 12 are arranged at intervals, and the first connecting portion 23 and the second connecting portion 24 are arranged at intervals. Both the first guiding member 11 and the second guiding member 12 are protrusions protruding from the outer wall of the inner layer tube 1, and the first guiding portion 21, the second guiding portion 22, the first connecting portion 23, and the second connecting portion 24 are all grooves. The protrusion structures are arranged on the same circumferential surface of the inner layer tube 1, so that both protrusion structures can be connected to the connecting portion after being driven to rotate.

[0044] It can be understood that in specific implementation, the second guiding member 12 is a strip-shaped protrusion extending along the circumferential direction of the inner layer tube 1, with a length less than half of the circumference of the inner circumferential surface of the inner layer tube 1. The first guiding member 11 is a rhombic protrusion arranged along the axial direction of the inner layer tube 1. The distance between the first guiding member 11 and the second guiding member 12 is one-fifth of the total length of the inner layer tube 1, forming a regular spaced arrangement.

[0045] It can be understood that the protrusion structure is integrally formed with the inner layer tube 1 and is made of the same polyethylene material.

[0046] Since both the first guiding member 11 and the second guiding member 12 are protrusions on the outer wall of the inner layer tube 1, the protrusions can move along the groove of the guiding portion or rotate along the groove of the connecting portion, improving the assembly efficiency; at the same time, because the first guiding member 11 and the second guiding member are arranged at intervals (spaced along the length direction), when the first guiding member 11 moves along the first guiding portion 21, the second guiding portion 22 will not enter the first guiding portion 21, and when the second guiding member 12 moves along the second guiding portion 22, the first guiding portion 21 will not enter the second guiding portion 22, thus interfering with the movement of the first guiding member 11 or the second guiding member 12, thereby improving the assembly efficiency of the inner layer tube 1 and the outer layer tube 2.

[0047] In other embodiments of the present invention, the first guiding member 11 is a slider, the second guiding member 12 is a slide bar, and the length of the first guiding member 11 is less than that of the second guiding member 12; the first guiding portion 21, the second guiding portion 22, the first connecting portion 23, and the second connecting portion 24 are all chutes.

[0048] It can be understood that the slider can be in the shape of a prism, a frustum of a cone, etc., and the slide bar can be a semi-cylindrical structure or a prism structure.

[0049] Since the main purpose of the first guiding member 11 being driven to move in the first connecting portion 23 is to quickly move to the fixed position between the inner tube body 1 and the outer tube body 2, therefore, when the first guiding member 11 is a slider and the second guiding member 12 is a slide bar, the frictional resistance between the first guiding member 11 and the second guiding member 12 and the first guiding portion 21 and the second guiding portion 22 during the driven movement in the first guiding portion 21 and the second guiding portion 22 can be reduced, thereby improving the connection efficiency between the inner tube body 1 and the outer tube body 2; and since the second guiding member 12 is a slide bar, when the second guiding member 12 is driven to rotate into the second connecting portion 24, the contact area between the second guiding member 12 and the second connecting portion 24 is larger, thus enhancing the connection stability between the inner tube body 1 and the outer tube body 2.

[0050] Furthermore, the spacing distance L1 between the first guiding member 11 and the second guiding member 12 is greater than or equal to the spacing distance L2 between the first guiding portion 21 and the second guiding portion 22, so that when the first guiding member 11 moves along the first guiding portion 21 and the second guiding member 12 moves along the second guiding portion 22, the first guiding member 11 and the second guiding member 12 can be unaffected by the outer walls of the first guiding portion 21 and the second guiding portion 22, preventing the outer walls from hindering the movement of the guiding members and causing the assembly efficiency to decrease.

[0051] Furthermore, the number of the first guiding members 11 is equal to that of the first connecting portions 23, and the number of the second guiding members 12 is equal to that of the second connecting portions 24. Since the number of the first guiding members 11 is equal to that of the first connecting portions 23 and the number of the first connecting portions 23 is equal to that of the second connecting portions 24, the first guiding member 11 and the first connecting portion 23, and the second guiding member 12 and the second connecting portion 24 can be in one-to-one correspondence, improving the connection accuracy.

[0052] Furthermore, when the first guiding member 11 and the second guiding member 12 rotate into the first connecting portion 23 and the second connecting portion 24 and are fixedly connected, a gap is formed between the inner tube body 1 and the outer tube body 2. When the inner tube body 1 circulates a heat medium or other media, the gap can play roles such as heat insulation and oxygen isolation, improving the heat insulation, oxygen isolation and other effects of the PE double-layer tube body.

[0053] For the PE double-layer pipe body provided by this application, when connecting the inner pipe body 1 and the outer pipe body 2, one end of the inner pipe 2 is placed at one end of the outer pipe body 2, aligning the first guiding member 11 with the first guiding portion 21, and the second guiding member 12 with the second guiding portion 22. Then, drive the inner pipe body 1 or the outer pipe body 2, so that the first guiding member 11 moves along the first guiding portion 21 and the second guiding member 12 moves along the second guiding portion 22. According to the actual use environment, the actual lengths of the PE double-layer pipe bodies are different. Therefore, multiple first guiding members 11, second guiding members 12, first guiding portions 21, second guiding portions 22, first connecting portions 23 and second connecting portions 24 are provided. When the guiding member moves along the guiding portion, when reaching the forming state of the inner and outer pipe bodies, rotate the inner pipe body 1 or the outer pipe body 2. At this time, the guiding member can enter the connecting portion through the communicating portion until the inner pipe body 1 or the outer pipe body 2 cannot rotate relative to each other, thereby forming a stable state of the first pipe body and the second pipe body, that is, forming a PE double-layer pipe body.

[0054] As Figure 6 shown, on the other hand, this application provides a production process for a PE double-layer pipe body. The production process of the PE double-layer pipe body includes the following steps: S1: Flow molten polyethylene into the forming device respectively, and after standing and cooling, obtain the inner pipe body 1 and the outer pipe body 2 in a solid state respectively. Multiple first guiding members 11 and multiple second guiding members 12 are formed on the outer wall of the inner pipe body 1, and multiple first guiding portions 21, multiple second guiding portions 22, multiple first connecting portions 23 and multiple second connecting portions 24 are formed on the inner wall of the outer pipe body 2; S2: Align the first guiding member 11 and the second guiding member 12 with the first guiding portion 21 and the second guiding portion 22 respectively, and then insert one end of the inner pipe body 1 into the interior of the outer pipe body 2; S3: Drive the inner pipe body 1 to move inside the outer pipe body 2, select a suitable position according to the actual situation, and drive the outer pipe body 2 or the inner pipe body 1 to rotate circumferentially along the outer pipe body 2 or the inner pipe body 1, so that the first guiding member 11 and the second guiding member 12 are gradually connected to the first connecting portion 23 and the second connecting portion 24 respectively, until the outer pipe body 2 and the inner pipe body 1 are stably connected, and mating plugs 3 and sockets 4 are formed at both ends; S4: Fill the foam agent between the interlayers of the connected inner pipe body 1 and outer pipe body 2, stand and cure to obtain the PE double-layer pipe body; S5: Align the first guiding member 11 and the second guiding member 12 of one section of the PE double-layer pipe body with the first guiding portion 21 and the second guiding portion 22 of another section of the PE double-layer pipe body, and insert the plug 3 of one section of the PE double-layer pipe body into the socket 4 of another section of the PE double-layer pipe body until one section of the PE double-layer pipe body and another section of the PE double-layer pipe body are in contact; S6: Rotate one section of the PE double-layer pipe body circumferentially along the other section of the PE double-layer pipe body, so that the first guide member 11 and the second guide member 12 of one section of the PE double-layer pipe body are gradually connected to the first connection portion 23 and the second connection portion 24 of the other section of the PE double-layer pipe body respectively, until the two sections of the PE double-layer pipe body are stably connected; S7: Treat the connection of the inner pipe bodies 1 of the two sections of the PE double-layer pipe body at a temperature of 120°C - 125°C, so that the first guide member 11 and the second guide member 12 of one section of the PE double-layer pipe body are in a molten state within the first connection portion 23 and the second connection portion 24 of the other section of the PE double-layer pipe body. After standing and cooling, the inner pipe bodies 1 of the two sections of the PE double-layer pipe body are fixedly connected; S8: Add a connecting member at the joint of the outer pipe bodies 2 of the two sections of the PE double-layer pipe body, and treat the joint of the connecting member and the outer pipe bodies 2 of the two sections of the PE double-layer pipe body at a temperature of 120°C - 140°C, so that the joint is in a molten state; S9: After standing and cooling, a pipe body after connecting multiple sections of the PE double-layer pipe body is obtained.

[0055] In the above production process of the PE double-layer pipe body, S1 mainly realizes the forming of the inner pipe body 1 and the outer pipe body 2. Specifically, polyethylene is heated to melt at any temperature between 120°C and 140°C and injected into the inner mold. After cooling, the inner pipe body 1 is formed, and a plurality of wedge-shaped first guiding members 11 and a plurality of trapezoidal second guiding members 12 are evenly distributed along the circumferential direction of its outer wall. The height of the guiding members is 1 mm - 3 mm. The outer pipe body 2 is made of the same material as the inner pipe body 1, and the inner wall is provided with a first guiding portion 21 matching the first guiding member 11, a first connecting portion 23, a second guiding portion 22 matching the second guiding member 12, and a second connecting portion 24. In S2 - S3, it is the preliminary assembly of the inner pipe body 1 and the outer pipe body 2. The front end of the inner pipe body 1 is introduced and inserted into the outer pipe body 2 at a uniform speed through a traction device or a hydraulic propulsion device. The first guiding member 11 and the second guiding member 12 slide along the axial first guiding portion 21 and the second guiding portion 22 until there is a distance L between the inner pipe body 1 and the outer pipe body 2 (the distance between two adjacent first guiding members 11 is L). Then, the circumferential rotation of the inner and outer pipe bodies is locked. The outer pipe body 2 is rotated at a uniform speed using a rotating machine or manually. The first guiding member 11 is screwed into the first connecting portion 23, and the second guiding member 12 is screwed into the second connecting portion 24. When filling the foaming agent in S5, the foaming agent can be a polyurethane foaming agent, or one of the physical foaming agents injected under nitrogen pressure or an epoxy resin foaming agent. In S6, it is the preliminary assembly of the PE double-layer pipe body. The plug 3 of one section of the PE double-layer pipe body is introduced into the socket 4 of another section of the PE double-layer pipe body. The first guiding member 11 and the second guiding member 12 of one section of the PE double-layer pipe body slide along the first guiding portion 21 and the second guiding portion 22 of another section of the PE double-layer pipe body until the two sections of the PE double-layer pipe body are in contact, and then the circumferential rotation of the PE double-layer pipe body is locked. S7 - S9: When connecting the inner pipe body 1 and the outer pipe body 2, a heating plate or an electrofusion method is used to melt the guiding member and the connecting portion so that the connection becomes a molten state and then cools to a fixed state. During this process, only the connection should be heated or electrofused to avoid large-area melting, which may cause a large amount of deformation at the connection of the inner and outer pipe bodies and result in structural failure.

[0056] When a large-diameter pipe body is required in the use environment, a bracket is used to support the outer pipe body 2. For the convenience of insertion and fixation, the first guiding member 11 and the second guiding member 12 have a certain elasticity to adapt to slight deformation during the insertion and fixation processes and ensure that the structure does not fail.

[0057] In other embodiments of the present invention, a plurality of dovetail-shaped first guiding members 11 and a plurality of hemispherical second guiding members 12 are provided on the outer wall of the inner pipe body 1; correspondingly, axial guide grooves and annular clamping grooves are provided on the inner wall of the outer pipe body 2, and the groove depth is 1 - 2.5 mm.

[0058] It can be understood that the surfaces of the first guiding member 11 and the second guiding member 12 are coated with a low-friction coefficient coating to ensure convenient assembly.

[0059] Understandably, the guiding member and the connecting portion can be provided with a sound feedback mechanism. When rotated until a "click" sound occurs, it means it has rotated to the fixed position.

[0060] In the above production process of the PE double-layer pipe body, by providing a first guiding member 11 and a second guiding member 12 on the outer wall of the inner-layer pipe body 1, and correspondingly providing a first guiding portion 21, a second guiding portion 22, a first connecting portion 23 and a second connecting portion 24 on the inner wall of the outer-layer pipe body 2, a phased guiding mechanism is formed; the guiding member moves along the extending direction of the guiding portion to ensure that the inner-layer pipe body 1 is axially inserted into the outer-layer pipe body 2 quickly and accurately, avoiding deflection or jamming; by rotation, the guiding member and the connecting portion are used to realize the circumferential fixation of the inner and outer layer pipe bodies 2, preventing relative displacement during subsequent foaming or use. This design significantly improves the assembly efficiency and at the same time reduces the difficulty of manual adjustment; after the foaming agent is filled into the interlayer of the inner and outer layer pipe bodies 2 and cured, the formed foaming layer has the functions of heat preservation, sound insulation and compressive resistance; the insertion and rotation type multi-section pipe connection method significantly improves the assembly efficiency and at the same time reduces the difficulty of manual adjustment; through the fusion connection of the guiding member and the connecting portion, the molecular-level fusion of the inner-layer pipe body 1 is realized, and the strength of the connection part is close to that of the pipe body itself, eliminating the risk of leakage; using an independent connecting member to weld two sections of the outer-layer pipe body 2 not only makes up for the defect that the foaming layer cannot be directly welded, but also forms an integral structure through hot melting to improve the impact resistance; this dual connection method solves the problems of poor sealing and insufficient durability caused by the traditional connection of PE pipe bodies relying on glue or mechanical clamps.

[0061] According to this embodiment of the present invention, one end of the PE double-layer pipe body formed in step S4 is closed with a cap; the position where the foaming agent is filled is aligned with the first guiding portion 21 and the second guiding portion 22, and the foaming agent is injected along the extending direction of the first guiding portion 21 and the second guiding portion 22. Closing one end of the PE double-layer pipe body with a cap forms a closed cavity, preventing the foaming agent from leaking, ensuring stable foaming pressure, and enabling the foaming agent to fully fill the interlayer between the inner-layer pipe body 1 and the outer-layer pipe body 2.

[0062] Understandably, the shape of the cap is adapted to that of the plug 3 or the socket 4.

[0063] Furthermore, the cap is provided with an observation portion. The cap can be made of transparent acrylic material. The observation portion is used to monitor the filling degree of the foaming agent at the other end in the interlayer of the PE double-layer pipe body when injecting the foaming agent. By integrating the observation portion on the cap, the visual monitoring and precise control of the foaming agent filling process are realized.

[0064] In other embodiments of the present invention, in the PE double-layer tube body formed in step S4; align the positions where the foaming agent is filled with both ends of the first guiding portion 21 and the second guiding portion 22, and inject the foaming agent simultaneously along both ends of the first guiding portion 21 and the second guiding portion 22; when the foaming agent overflows at both ends of the PE double-layer tube body, stop injecting. By injecting the foaming agent simultaneously from both ends of the first guiding portion 21 and the second guiding portion 22 of the PE double-layer tube body, the foaming agent is evenly diffused along the interlayer between the inner tube body 1 and the outer tube body 2, reducing the problems of local bubble aggregation or incomplete filling caused by unilateral injection.

[0065] Furthermore, the foaming agent includes a polyurethane prepolymer. The foaming agent contains a polyurethane prepolymer, which forms a tight bond with the PE pipe wall during the curing process, avoiding the problem of easy delamination of traditional physical foaming agents, and ensuring the interfacial bonding strength between the foaming layer and the inner and outer tube bodies; the polyurethane foaming layer has excellent compressive strength and low density, effectively buffering external impact loads while ensuring the overall light weight of the tube body; the polyurethane closed-cell structure significantly reduces the thermal conductivity coefficient, and can effectively adapt to the transportation of low-temperature fluids or environments where temperature stability is required.

[0066] It is worth mentioning that the injection amount of the foaming agent per unit time is less than or equal to the amount of the foaming agent flowing through the inner grooves of the first guiding portion 21 and the second guiding portion 22 per unit time. By precisely controlling the injection rate of the foaming agent and the flow capacity of the inner grooves of the first guiding portion 21 and the second guiding portion 22, precise control of the foaming injection of the PE double-layer tube body is achieved; by limiting the injection amount of the foaming agent per unit time ≤ the flow capacity of the first guiding portion 21 and the second guiding portion 22, the laminar flow state of the foaming agent in the guiding portion is ensured to be stable, avoiding uneven filling.

[0067] It is worth mentioning that a connector is added at the joint of the outer tube bodies 2 of two sections of the PE double-layer tube body, and the joint of the connector and the two outer tube bodies 2 is processed at a temperature of 120°C - 140°C to make the joint in a molten state; the connector is in interference fit with the two tube bodies, and the interference fit design causes a pre-tightening force to be generated between the inner tube body 1 and the outer tube body 2 before heating, making the joint formed by the molten material have better sealing performance after cooling and reducing the possibility of leakage.

[0068] Preferably, the connector is made of the same material as the inner tube body 1 or the outer tube body 2, such as polyethylene with the same melting temperature.

[0069] It is worth mentioning that at the joint of the inner tube body 1 of the two-section PE double-layer tube body, the guide piece and the connecting part are processed at a temperature of 120°C - 140°C, so that the guide piece is in a molten state within the connecting part. After standing and cooling, the inner tube body 1 is fixedly connected; it also includes adding a connecting piece to the first connecting part 23 and the second guiding part 22. When processing the guide piece and the connecting part at a temperature of 120°C - 140°C, the connecting piece is processed simultaneously to achieve the coordinated fusion of the inner and outer tube bodies 2 and improve the connection efficiency; at the same time, a connecting piece is added at the joint to make the material in a molten state at the tube body connection more, and it is more stable after cooling and fixing.

[0070] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A PE double-layer pipe body, characterized in that, Comprising: An inner tube body, the inner tube body includes a first guide member and a second guide member, and the first guide member and the second guide member are arranged on the same circumferential surface of the outer wall of the inner tube body; An outer tube body, the outer tube body is arranged outside the inner tube body, the outer tube body includes a first guide portion and a second guide portion, the first guide portion and the second guide portion are respectively adapted to the first guide member and the second guide member, the first guide portion and the second guide portion are arranged on the inner wall of the outer tube body, and the first guide portion and the second guide portion are arranged along the length direction of the outer tube body; The outer tube body further includes a first connection portion and a second connection portion, the first connection portion and the second connection portion are respectively adapted to the first guide member and the second guide member, the first connection portion and the second connection portion are arranged on the inner wall of the outer tube body, and the first connection portion and the second connection portion are respectively communicated with the first guide portion and the second guide portion, and the first connection portion and the second connection portion are arranged on the same circumferential surface of the outer tube body.

2. The PE double-layer tube body according to claim 1, wherein, A first guide member inclined surface and a second guide member inclined surface are respectively arranged on the first guide member and the second guide member; a first guide portion inclined surface and a second guide portion inclined surface are respectively arranged on the first guide portion and the second guide portion, and the first guide portion inclined surface and the second guide portion inclined surface are respectively adapted to the first guide member inclined surface and the second guide member inclined surface.

3. The PE double-layer tube body according to claim 1, wherein The first guide member and the second guide member are arranged at intervals, and the first connection portion and the second connection portion are arranged at intervals.

4. The PE double-layer pipe body according to claim 3, characterized in that, The number of the first guide members is equal to the number of the first connection portions, and the number of the second guide members is equal to the number of the second connection portions.

5. The PE double-layer tube body according to any one of claims 1-4, characterized in that, A gap is left between the inner tube body and the outer tube body.

6. A production process of a PE double-layer pipe body, characterized in that, Including the following steps: S1: Flowing molten polyethylene into a forming device respectively, standing and cooling to obtain the inner tube body and the outer tube body in a solid state respectively. A plurality of first guide members and a plurality of second guide members are formed on the outer wall of the inner tube body, and a plurality of first guide portions, a plurality of second guide portions, a plurality of first connection portions and a plurality of second connection portions are formed on the inner wall of the outer tube body; S2: Aligning the first guide member and the second guide member with the first guide portion and the second guide portion respectively, and then inserting one end of the inner tube body into the inside of the outer tube body; S3: Driving the inner tube body to move inside the outer tube body, and selecting a suitable position according to the actual situation to drive the outer tube body or the inner tube body to rotate circumferentially along the outer tube body or the inner tube body, so that the first guide member and the second guide member are gradually connected with the first connection portion and the second connection portion respectively, so that the outer tube body and the inner tube body are stably connected, and plugs and sockets are formed at both ends; S4: Filling a foaming agent between the interlayers of the connected inner tube body and the outer tube body, standing and curing to obtain a PE double-layer tube body; S5: Align the first guiding member and the second guiding member of one section of the PE double-layer tube body with the first guiding portion and the second guiding portion of the other section of the PE double-layer tube body, and insert the plug of one section of the PE double-layer tube body into the socket of the other section of the PE double-layer tube body until one section of the PE double-layer tube body abuts against the other section of the PE double-layer tube body; S6: Drive one section of the PE double-layer tube body to rotate circumferentially along the other section of the PE double-layer tube body, so that the first guiding member and the second guiding member of one section of the PE double-layer tube body are gradually connected to the first connecting portion and the second connecting portion of the other section of the PE double-layer tube body respectively, so that the two sections of the PE double-layer tube body are stably connected; S7: Treat the connection of the inner tube bodies of the two sections of the PE double-layer tube body at a temperature of 120°C - 125°C, so that the first guiding member and the second guiding member of one section of the PE double-layer tube body are in a molten state within the first connecting portion and the second connecting portion of the other section of the PE double-layer tube body. After standing and cooling, the inner tube bodies of the two sections of the PE double-layer tube body are fixedly connected; S8: Add a connecting member at the joint of the outer tube bodies of the two sections of the PE double-layer tube body, and treat the joint of the connecting member and the outer tube bodies of the two sections of the PE double-layer tube body at a temperature of 120°C - 140°C, so that the joint is in a molten state; S9: After standing and cooling, obtain the tube body after connecting multiple sections of the PE double-layer tube body.

7. The PE double-layer tube body according to claim 6, wherein, Seal one end of the PE double-layer tube body formed in step S4 with a cap; Align the position where the foaming agent is filled with the first guiding portion and the second guiding portion, and inject the foaming agent along the extending direction of the first guiding portion and the second guiding portion.

8. The PE double-layer pipe body according to claim 7, characterized in that, The cap is provided with an observation portion, and the observation portion is used to monitor the filling degree of the foaming agent at the other end in the interlayer of the PE double-layer tube body when injecting the foaming agent.

9. The PE double-layer pipe body according to claim 6, characterized in that, In the PE double-layer tube body formed in step S4; Align the position where the foaming agent is filled with both ends of the first guiding portion and the second guiding portion, and inject the foaming agent simultaneously along both ends of the first guiding portion and the second guiding portion; When the foaming agent overflows at both ends of the PE double-layer tube body, stop injecting.

10. The PE double-layer tube body according to claim 7 or 9, characterized in that, The foaming agent includes polyurethane prepolymer.

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