Flame-retardant anti-cracking HDPE (high-density polyethylene) double-wall corrugated pipe

Abstract

The utility model belongs to the technical field of corrugated pipes, and particularly relates to a flame-retardant anti-cracking HDPE double-wall corrugated pipe which comprises an outer pipe body in a corrugated pipe shape and an inner pipe body arranged in the outer pipe body, and a filling space is formed between the inner pipe body and the outer pipe body. The reinforcing layer is arranged in the filling space and divides the filling space into an outer space and an inner space; the expansion mechanism is arranged in the outer space; wherein the outer space is filled with polystyrene foam, the expansion mechanism is wrapped with the polystyrene foam, and a flame-retardant layer is arranged on the side, away from the inner space, of the reinforcing layer. The flame-retardant pipe has the beneficial effects that the flame-retardant layer is arranged on the side, away from the inner space, of the reinforcing layer, so that the flame-retardant performance of the whole pipe is effectively improved. And the flame-retardant layer can isolate a fire source and reduce the risk of fire spreading, so that fluid in the pipeline is protected from being influenced by the fire.

Description

Technical Field

[0001] The present application belongs to the technical field of corrugated pipes, and in particular relates to a flame-retardant and crack-resistant HDPE double-wall corrugated pipe. Background Art

[0002] Double-wall corrugated pipe is a new type of lightweight pipe made of high-density polyethylene. It has the characteristics of light weight, high pressure resistance, good toughness, fast construction, long life, etc. Its excellent pipe wall structure design greatly reduces the cost compared with other structures of pipes. It is widely used at home and abroad.

[0003] However, the existing double-wall corrugated pipes have low pressure and impact resistance. When impacted, they are easily deformed or even damaged, causing cracks in the corrugated pipes and reducing their service life. In addition, the existing double-wall corrugated pipes usually do not have flame retardant functions. When encountering flames, they are prone to continuous burning and have low safety.

[0004] The patent with publication number CN220134844U discloses a new type of compression-resistant HDPE double-wall corrugated pipe, which solves the problem of insufficient compression resistance of corrugated pipes. It includes an outer pipe body and an inner pipe body. The outer pipe body is in the shape of a corrugated pipe. A pressure-resistant layer is arranged between the outer pipe body and the inner pipe body. The pressure-resistant layer has compression-resistant ribs pressed against the wave crests of the outer pipe body and compression-resistant grooves fitted against the wave troughs of the outer pipe body. A reinforcement mechanism and a buffer mechanism are arranged between the pressure-resistant layer and the inner pipe body, and an elastic reset mechanism is arranged between the inner pipe body and the pressure-resistant layer.

[0005] The above patent improves the pressure resistance by setting a pressure-resistant layer and a reinforcing structure between the outer tube body and the inner tube body, and improves the impact resistance by a buffer layer, so that the corrugated tube is not easy to crack. However, in actual use, it does not have good flame retardant ability and is prone to safety accidents, which requires improvement. Utility Model Content

[0006] The purpose of this application is to provide a flame retardant and crack resistant HDPE double-wall corrugated pipe that can solve the above problems.

[0007] The purpose of this application is to provide a flame retardant and crack resistant HDPE double-wall corrugated pipe, comprising:

[0008] The outer tube body is in the shape of a corrugated tube.

[0009] An inner tube body is disposed inside the outer tube body and forms a filling space between the outer tube body;

[0010] A reinforcing layer is disposed in the filling space and divides the filling space into an outer space and an inner space;

[0011] An expansion mechanism is disposed in the outer space;

[0012] The outer space is filled with foamed rubber, the foamed rubber is wrapped around the expansion mechanism, and a flame retardant layer is arranged on the side of the reinforcement layer away from the inner space.

[0013] The above-mentioned design of a flame-retardant and crack-proof HDPE double-wall corrugated pipe further enhances its flame retardancy and crack resistance while retaining the advantages of traditional HDPE double-wall corrugated pipes. By setting a flame-retardant layer on the side of the reinforcement layer away from the inner space, the flame retardant performance of the entire pipe is effectively improved. The flame-retardant layer can isolate the fire source and reduce the risk of fire spread, thereby protecting the fluid inside the pipeline from the fire. The outer tube body is in the shape of a corrugated tube, which has good deformation resistance and crack resistance. In addition, the setting of the reinforcement layer divides the filling space into an outer space and an inner space, further enhancing the overall strength and stability of the pipe. The combined use of the expansion mechanism and the foaming glue can expand the foaming glue through the action of the expansion mechanism when the pipeline is cracked by external pressure or impact, and the foaming glue oozes out and foams to form a foam body at the cracks or holes. The foaming glue will solidify when it encounters moisture, thereby repairing the cracks and ensuring the sealing of the cracks and damage.

[0014] The HDPE material itself has excellent corrosion resistance, aging resistance and chemical stability, which enables the pipeline to operate stably for a long time in various environments. The addition of components such as flame retardant layer, reinforcement layer and expansion mechanism further enhances the performance of the pipeline, improves its safety and reliability, and significantly improves its overall flame retardancy and crack resistance.

[0015] Further, the expansion mechanism comprises:

[0016] An expansion tube is arranged in the outer space;

[0017] A gas injection pipe, one end of which is connected to the expansion pipe and the other end of which extends outside the outer pipe;

[0018] A support frame is arranged in the external space and connected to the expansion tube;

[0019] Wherein, the support frame is connected to the inner wall of the outer tube body.

[0020] The expansion tube is arranged in the external space. When the bellows is cracked or broken due to factors such as external pressure, the expansion tube expands and squeezes the foam glue, squeezes the foam glue to the broken part, fills the broken part, and prevents the bellows from further cracking. At the same time, the expansion tube is an elastic rubber expansion tube, which can maintain a stable expansion state for a long time. One end of the air injection pipe is connected to the expansion tube, and the other end extends outside the outer tube body, which is used to inject gas or other media into the expansion tube to expand it. Through the air injection pipe, the expansion degree of the expansion tube can be easily controlled to meet different needs. The support frame is arranged in the external space and connected to the expansion tube. Its main function is to fix the position of the expansion tube to prevent it from displacement or deformation during the expansion process. The support frame is also connected to the inner wall of the outer tube body, which further enhances the connection strength and stability between it and the pipeline as a whole.

[0021] In addition, in order to accurately detect whether the bellows is cracked, the present application may also provide a pressure sensor to further detect changes in pressure, thereby monitoring whether the entire bellows is cracked and ensuring technical treatment of the cracks.

[0022] Further: the gas injection pipe is provided with a sealing structure, and the sealing structure comprises:

[0023] A sealing head is arranged in the opening of the gas injection pipe, the outer wall of the sealing head is in contact with the inner wall of the gas injection pipe, the inner wall is stepped, and an air hole is arranged at the center of the sealing head;

[0024] The plug body comprises a gripping section, a connecting section and a sealing section which are connected in sequence, and the sealing section is in contact with the inner wall of the sealing head;

[0025] Wherein, an external thread is arranged on the inner wall of the sealing head, and an external thread matching the external thread is arranged on the connecting section.

[0026] The sealing head is arranged inside the opening of the gas injection pipe, and its outer wall is tightly fitted with the inner wall of the gas injection pipe, which can effectively prevent gas or liquid from leaking from the interface between the gas injection pipe and the external environment. The inner wall of the sealing head is designed to be stepped. Such a design not only increases the contact area with the sealing section of the plug body and improves the sealing effect, but also provides convenience for the installation and disassembly of the plug body. An air hole is arranged in the center of the sealing head to allow gas or medium to pass through when necessary. The plug body is connected in sequence by a holding section, a connecting section and a sealing section. The holding section is convenient for the user to hold and operate, and the connecting section is connected to the sealing head to ensure that the plug body can be fixed in the gas injection pipe. The sealing section is tightly fitted with the inner wall of the sealing head to form a seal. At the same time, an external thread is arranged on the connecting section, which is adapted to the external thread on the inner wall of the sealing head. The threaded connection method ensures a tight connection and reliable sealing between the plug body and the sealing head.

[0027] When it is necessary to inject gas or medium into the expansion tube, the user can unscrew the plug body through the holding section to expose the pores, thereby allowing gas or medium to pass through. After the injection is completed, the user only needs to screw the plug body back into the gas injection tube, and rotate the plug body to make the external thread on the connecting section tightly engage with the external thread on the inner wall of the sealing head, and the sealing section and the inner wall of the sealing head fit tightly to form a seal. The structure is simple, the operation is convenient and the sealing effect is good. The user only needs to rotate the plug body to complete the sealing and opening operations. The threaded connection and the stepped design ensure the reliable isolation of the gas injection tube from the external environment, improve the safety of the expansion mechanism, and prevent internal gas leakage.

[0028] Furthermore, the sealing structure further comprises:

[0029] An installation ring groove is arranged on the inner wall of the sealing head, and a first sealing ring is arranged on the installation ring groove;

[0030] A sealing member is arranged at the connection between the sealing head and the sealing section, and the cross section of the sealing member is in an "N" shape;

[0031] Wherein, a second sealing ring is arranged at the bending part of the sealing member.

[0032] The mounting ring groove is arranged on the inner wall of the sealing head for placing the first sealing ring. When the plug body is screwed into the gas injection pipe, the first sealing ring will be compressed and tightly attached to the inner wall of the sealing head and the outer surface of the plug body, thereby effectively preventing the leakage of gas or medium. The seal is arranged at the connection between the sealing head and the sealing section, and its cross section is designed in an "N" shape, so that the seal can produce greater deformation when under pressure, so as to better fit the surface of the sealing head and the sealing section and enhance the sealing effect. A second sealing ring is arranged at the bend of the seal. These second sealing rings are made of elastic material, which can further fill the gap between the seal and the sealing head and the sealing section, and improve the reliability of the seal. Through the multi-level sealing design, that is, the coordinated use of the first sealing ring, the seal and the second sealing ring, a multi-level sealing protection is achieved, which greatly reduces the leakage of gas, thereby ensuring the expansion effect and ensuring the normal filling of the foaming liquid when the bellows is broken.

[0033] During installation, the user only needs to screw the plug body into the gas injection pipe so that the first sealing ring and the "N"-shaped seal fit tightly with the sealing head. When the gas injection pipe needs to be opened, the user only needs to rotate the plug body in the opposite direction and pull it out of the gas injection pipe.

[0034] Furthermore, reinforcing ribs are arranged in the inner space, and the reinforcing ribs are arranged vertically and connected to the reinforcing layer.

[0035] The reinforcement ribs are vertically arranged in the inner space and connected to the reinforcement layer, so that the reinforcement ribs can directly enhance the strength of the reinforcement layer and transfer this strength to the entire pipeline. The reinforcement ribs are arranged vertically to effectively increase the pressure resistance and impact resistance of the pipeline, so that the pipeline can remain stable when subjected to external pressure or impact. When the pipeline is subjected to external forces such as uneven soil settlement, it can maintain good stability and reduce the risk of deformation and cracking.

[0036] Furthermore, the outer tube body is provided with an injection port, which is communicated with the external space and is used for injecting foam glue into the external space.

[0037] The injection port is set on the outer tube body and is directly connected to the outer space. The foam glue can directly enter the outer space of the corrugated tube through the injection port to fill and supplement the foam glue in the outer space. The foam glue is injected into the outer space through the injection port using a special injection device. During the injection process, the injection speed and pressure need to be controlled to ensure that the foam glue can be evenly distributed and fill the entire outer space.

[0038] The beneficial effects of this application are:

[0039] 1. By setting a flame retardant layer on the side of the reinforcement layer away from the inner space, the flame retardant performance of the entire pipe is effectively improved. The flame retardant layer can isolate the fire source and reduce the risk of fire spread, thereby protecting the fluid inside the pipeline from the impact of fire;

[0040] 2. The outer tube is in the shape of a corrugated tube, which has good resistance to deformation and cracking. In addition, the reinforcement layer is set to separate the filling space into outer space and inner space, further enhancing the overall strength and stability of the pipe;

[0041] 3. The combined use of the expansion mechanism and the foam glue can make the foam glue expand through the action of the expansion mechanism when the pipeline is cracked by external pressure or impact, and the foam glue will seep out and foam to form a foam body in the cracks or holes. The foam glue will solidify when it encounters moisture, thereby repairing the cracks and ensuring that the cracks and damaged parts are sealed. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a structural schematic diagram of the utility model;

[0043] Figure 2 It is a top view of the utility model;

[0044] Figure 3 It is a partial enlarged schematic diagram of the internal structure of the utility model;

[0045] Figure 4 yes Figure 3 A is an enlarged view of the middle image.

[0046] The reference numerals in the figure are: 100, outer tube body; 110, injection port; 200, inner tube body; 300, filling space; 310, outer space; 320, inner space; 330, foam; 340, reinforcing ribs; 400, reinforcing layer; 410, flame retardant layer; 500, expansion mechanism; 510, expansion tube; 520, air injection tube; 530, support frame; 600, sealing structure; 610, sealing head; 611, air hole; 620, plug body; 621, holding section; 622, connecting section; 623, sealing section; 630, mounting groove; 640, first sealing ring; 650, sealing element; 660, second sealing ring. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0048] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0049] The flame retardant and crack resistant HDPE double-wall corrugated pipe provided in the embodiment of the present application is described in detail below through specific embodiments and application scenarios in conjunction with the accompanying drawings.

[0050] Embodiment 1:

[0051] like Figures 1 to 3 As shown, the embodiment of the present application provides a flame retardant and crack resistant HDPE double-wall corrugated pipe, comprising:

[0052] The outer tube body 100 is in the shape of a corrugated tube.

[0053] The inner tube body 200 is disposed inside the outer tube body 100 and forms a filling space 300 with the outer tube body 100;

[0054] The reinforcing layer 400 is disposed in the filling space 300 and divides the filling space 300 into an outer space 310 and an inner space 320;

[0055] The expansion mechanism 500 is disposed in the outer space 310;

[0056] The outer space 310 is filled with foam glue 330 , and the foam glue 330 is wrapped around the expansion mechanism 500 . A flame retardant layer 410 is provided on the side of the reinforcement layer 400 away from the inner space 320 .

[0057] In some implementations of the embodiments of the present application, Figure 1 As shown, the above-mentioned flame-retardant and crack-resistant HDPE double-wall corrugated pipe design retains the advantages of traditional HDPE double-wall corrugated pipes while further enhancing its flame retardancy and crack resistance. By setting a flame-retardant layer 410 on the side of the reinforcing layer 400 away from the inner space 320, the flame retardant performance of the entire pipe is effectively improved. The flame-retardant layer 410 can isolate the fire source and reduce the risk of fire spread, thereby protecting the fluid inside the pipeline from the impact of the fire. The outer tube body 100 is in the shape of a corrugated tube, which itself has good resistance to deformation and cracking. In addition, the setting of the reinforcing layer 400 divides the filling space 300 into an outer space 310 and an inner space 320, further enhancing the overall strength and stability of the pipe. The combined use of the expansion mechanism 500 and the foam glue 330 can expand the foam glue 330 through the action of the expansion mechanism 500 when the pipeline is cracked due to external pressure or impact, and the foam glue 330 will seep out and foam to form a foam body in the cracks or holes. The foam glue 330 will solidify when it encounters moisture, thereby repairing the cracks and ensuring that the cracks and damaged parts are sealed.

[0058] The HDPE material itself has excellent corrosion resistance, aging resistance and chemical stability, so that the pipeline can operate stably for a long time in various environments. The addition of components such as the flame retardant layer 410, the reinforcement layer 400 and the expansion mechanism 500 further enhances the performance of the pipeline, improves its safety and reliability, and significantly improves its overall flame retardancy and crack resistance.

[0059] Furthermore, an injection port 110 is provided on the outer tube body 100 . The injection port 110 is communicated with the outer space 310 and is used for injecting the foaming glue 330 into the outer space 310 .

[0060] The injection port 110 is provided on the outer tube body 100 and is directly connected to the outer space 310. The foam glue 330 can directly enter the outer space 310 of the corrugated tube through the injection port 110 to achieve filling and replenishment of the foam glue 330 in the outer space 310. The foam glue 330 is injected into the outer space 310 through the injection port 110 using a dedicated injection device. During the injection process, the injection speed and pressure need to be controlled to ensure that the foam glue 330 can be evenly distributed and fill the entire outer space 310.

[0061] Embodiment 2:

[0062] The embodiment of the present application provides a flame retardant and crack resistant HDPE double-wall corrugated pipe. In addition to the above-mentioned technical features, the flame retardant and crack resistant HDPE double-wall corrugated pipe of the embodiment of the present application also includes the following technical features.

[0063] like Figure 3 and Figure 4 As shown, the expansion mechanism 500 includes:

[0064] An expansion tube 510 is disposed in the outer space 310;

[0065] A gas injection pipe 520, one end of which is connected to the expansion pipe 510, and the other end of which extends outside the outer tube body 100;

[0066] A support frame 530 is disposed in the outer space 310 and connected to the expansion tube 510;

[0067] The support frame 530 is connected to the inner wall of the outer tube body 100 .

[0068] In the embodiment of the present application, the expansion tube 510 is arranged in the outer space 310. When the bellows is cracked or broken due to factors such as external pressure, the expansion tube 510 expands and squeezes the foam glue 330, squeezes the foam glue 330 to the broken part, fills the broken part, and prevents the bellows from further cracking. At the same time, the expansion tube 510 is an elastic rubber expansion tube 510, which can maintain a stable expansion state for a long time. One end of the gas injection tube 520 is connected to the expansion tube 510, and the other end extends to the outside of the outer tube body 100, which is used to inject gas or other media into the expansion tube 510 to expand it. Through the gas injection tube 520, the expansion degree of the expansion tube 510 can be conveniently controlled to meet different needs. The support frame 530 is arranged in the outer space 310 and connected to the expansion tube 510. Its main function is to fix the position of the expansion tube 510 to prevent it from displacement or deformation during the expansion process. The support frame 530 is also connected to the inner wall of the outer tube body 100, further enhancing the connection strength and stability between it and the entire pipeline.

[0069] In addition, in order to accurately detect whether the bellows is cracked, the present application may also provide a pressure sensor to further detect changes in pressure, thereby monitoring whether the entire bellows is cracked and ensuring technical treatment of the cracks.

[0070] Embodiment 3:

[0071] The embodiment of the present application provides a flame retardant and crack resistant HDPE double-wall corrugated pipe. In addition to the above-mentioned technical features, the flame retardant and crack resistant HDPE double-wall corrugated pipe of the embodiment of the present application also includes the following technical features.

[0072] like Figure 3 and Figure 4 As shown,

[0073] Further: A sealing structure 600 is provided on the gas injection pipe 520, and the sealing structure 600 includes:

[0074] The sealing head 610 is disposed in the opening of the gas injection pipe 520. The outer wall of the sealing head 610 is in contact with the inner wall of the gas injection pipe 520. The inner wall is stepped, and an air hole 611 is disposed at the center of the sealing head 610.

[0075] The plug body 620 includes a gripping section 621, a connecting section 622 and a sealing section 623 which are connected in sequence, and the sealing section 623 is in contact with the inner wall of the sealing head 610;

[0076] The inner wall of the sealing head 610 is provided with an external thread, and the connecting section 622 is provided with an external thread matching the external thread.

[0077] In the embodiment of the present application, the sealing head 610 is arranged inside the opening of the gas injection tube 520, and its outer wall is closely fitted with the inner wall of the gas injection tube 520, which can effectively prevent gas or liquid from leaking from the interface between the gas injection tube 520 and the external environment. The inner wall of the sealing head 610 is designed to be stepped, which not only increases the contact area with the sealing section 623 of the plug body 620 and improves the sealing effect, but also facilitates the installation and removal of the plug body 620. An air hole 611 is provided at the center of the sealing head 610 to allow gas or medium to pass through when necessary. The plug body 620 is formed by connecting the holding section 621, the connecting section 622 and the sealing section 623 in sequence. The holding section 621 is convenient for the user to hold and operate, and the connecting section 622 is connected to the sealing head 610 to ensure that the plug body 620 can be fixed in the gas injection tube 520. The sealing section 623 is closely fitted with the inner wall of the sealing head 610 to form a seal. At the same time, by providing an external thread on the connecting section 622, it is adapted to the external thread on the inner wall of the sealing head 610. The threaded connection ensures a tight connection and reliable sealing between the plug body 620 and the sealing head 610.

[0078] When it is necessary to inject gas or medium into the expansion tube 510, the user can unscrew the plug body 620 through the holding section 621 to expose the air hole 611, thereby allowing the gas or medium to pass through. After the injection is completed, the user only needs to screw the plug body 620 back into the gas injection tube 520, and rotate the plug body 620 to make the external thread on the connecting section 622 tightly engage with the external thread on the inner wall of the sealing head 610, and the sealing section 623 tightly fits with the inner wall of the sealing head 610, thereby forming a seal. The structure is simple, the operation is convenient and the sealing effect is good. The user only needs to rotate the plug body 620 to complete the sealing and opening operations. The threaded connection and the stepped design ensure the reliable isolation of the gas injection tube 520 from the external environment, improve the safety of the expansion mechanism 500, and prevent internal gas leakage.

[0079] Furthermore, the sealing structure 600 further includes:

[0080] The mounting ring groove 630 is provided on the inner wall of the sealing head 610, and a first sealing ring 640 is provided on the mounting ring groove 630;

[0081] The sealing member 650 is disposed at the connection between the sealing head 610 and the sealing section 623, and the cross section of the sealing member 650 is in an "N" shape;

[0082] Wherein, a second sealing ring 660 is disposed at each bending portion of the sealing member 650 .

[0083] The mounting ring groove 630 is arranged on the inner wall of the sealing head 610 for placing the first sealing ring 640. When the plug body 620 is screwed into the gas injection pipe 520, the first sealing ring 640 will be compressed and tightly attached to the inner wall of the sealing head 610 and the outer surface of the plug body 620, thereby effectively preventing the leakage of gas or medium. The sealing member 650 is arranged at the connection between the sealing head 610 and the sealing section 623. Its cross section is designed in an "N" shape, so that the sealing member 650 can produce greater deformation when subjected to pressure, so as to better fit the surface of the sealing head 610 and the sealing section 623 and enhance the sealing effect. Second sealing rings 660 are arranged at the bends of the sealing members 650. These second sealing rings 660 are made of elastic material, which can further fill the gap between the sealing member 650 and the sealing head 610 and the sealing section 623, thereby improving the reliability of the seal. Through the multi-level sealing design, that is, the coordinated use of the first sealing ring 640, the sealing member 650 and the second sealing ring 660, multi-level sealing protection is achieved, which greatly reduces gas leakage, thereby ensuring the expansion effect and ensuring the normal filling of the foaming liquid when the bellows ruptures.

[0084] During installation, the user only needs to screw the plug body 620 into the gas injection tube 520 so that the first sealing ring 640 and the "N"-shaped seal 650 fit tightly with the sealing head 610. When the gas injection tube 520 needs to be opened, the user only needs to rotate the plug body 620 in the opposite direction and pull it out of the gas injection tube 520.

[0085] Embodiment 4:

[0086] The embodiment of the present application provides a flame retardant and crack resistant HDPE double-wall corrugated pipe. In addition to the above-mentioned technical features, the flame retardant and crack resistant HDPE double-wall corrugated pipe of the embodiment of the present application also includes the following technical features.

[0087] like Figure 3 As shown, a reinforcing rib 340 is disposed in the inner space 320 , and the reinforcing rib 340 is vertically disposed and connected to the reinforcing layer 400 .

[0088] In the embodiment of the present application, the reinforcing rib 340 is vertically arranged in the inner space 320 and connected to the reinforcing layer 400, so that the reinforcing rib 340 can directly enhance the strength of the reinforcing layer 400 and transfer this strength to the entire pipeline. The reinforcing rib 340 is vertically arranged to effectively increase the pressure resistance and impact resistance of the pipeline, so that the pipeline can remain stable when subjected to external pressure or impact. When the pipeline is subjected to external forces such as uneven soil settlement, it can maintain good stability and reduce the risk of deformation and cracking.

[0089] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0090] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A flame retardant and crack resistant HDPE double-wall corrugated pipe, characterized by: include: An outer tube body (100), the outer tube body (100) is in the shape of a corrugated tube; An inner tube body (200) is disposed inside the outer tube body (100) and forms a filling space (300) with the outer tube body (100); A reinforcing layer (400) is disposed in the filling space (300) and divides the filling space (300) into an outer space (310) and an inner space (320); An expansion mechanism (500) is disposed in the outer space (310); The outer space (310) is filled with foam glue (330), the foam glue (330) is wrapped around the outside of the expansion mechanism (500), and a flame retardant layer (410) is provided on the side of the reinforcement layer (400) away from the inner space (320).

2. The flame-retardant and crack-resistant HDPE double-wall corrugated pipe according to claim 1, characterized in that: The expansion mechanism (500) comprises: An expansion tube (510) is disposed in the outer space (310); A gas injection pipe (520), one end of which is connected to the expansion pipe (510) and the other end of which extends outside the outer pipe body (100); A support frame (530) is disposed in the outer space (310) and connected to the expansion tube (510); The support frame (530) is connected to the inner wall of the outer tube body (100).

3. The flame retardant and crack resistant HDPE double-wall corrugated pipe according to claim 2, characterized in that: The gas injection pipe (520) is provided with a sealing structure (600), and the sealing structure (600) comprises: A sealing head (610) is arranged in the opening of the gas injection pipe (520), the outer wall of the sealing head (610) is in contact with the inner wall of the gas injection pipe (520), the inner wall is in a stepped shape, and an air hole (611) is arranged at the center of the sealing head (610); The plug body (620) comprises a gripping section (621), a connecting section (622) and a sealing section (623) which are connected in sequence, and the sealing section (623) is in contact with the inner wall of the sealing head (610); The inner wall of the sealing head (610) is provided with an external thread, and the connecting section (622) is provided with an external thread matching the external thread.

4. The flame retardant and crack resistant HDPE double-wall corrugated pipe according to claim 3, characterized in that: The sealing structure (600) further comprises: An installation ring groove (630) is arranged on the inner wall of the sealing head (610), and a first sealing ring (640) is arranged on the installation ring groove (630); A sealing member (650) is arranged at the connection between the sealing head (610) and the sealing section (623), and the cross section of the sealing member (650) is in an "N" shape; Wherein, a second sealing ring (660) is provided at the bending part of the sealing member (650).

5. The flame retardant and crack resistant HDPE double-wall corrugated pipe according to claim 4, characterized in that: A reinforcing rib (340) is disposed in the inner space (320), and the reinforcing rib (340) is vertically disposed and connected to the reinforcing layer (400).

6. The flame retardant and crack resistant HDPE double-wall corrugated pipe according to claim 5, characterized in that: The outer tube body (100) is provided with an injection port (110), which is in communication with the outer space (310) and is used for injecting the foaming glue (330) into the outer space (310).

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