Flame resistant bellows

Abstract

The utility model relates to a kind of flame-retardant corrugated pipes, including inner tube, intermediate barrier layer and outer sheath, still be equipped with wave crest and wave trough on inner tube, intermediate barrier layer is covered and is set in inner tube outer layer, outer sheath is covered in intermediate barrier layer outer layer, it is equipped with adhesive layer between inner tube and intermediate barrier layer, intermediate barrier layer is fixedly connected by adhesive layer and inner tube.The design of the utility model, effectively blocks high temperature interlayer gap penetration, so that the flame-retardant corrugated pipe can still maintain structural stability under high temperature environment, and layer and layer are not easy to separate.

Description

Technical Field

[0001] This utility model relates to the field of pipeline components, and in particular to the field of flame-retardant corrugated pipe. Background Technology

[0002] A bellows is a flexible tubular component with an axially corrugated structure, widely used in fluid transport, electrical insulation, mechanical protection, and thermal expansion and contraction compensation. Its structural characteristics endow it with excellent flexibility, bending, and sealing performance, making it valuable in automotive, construction, electronics, and industrial equipment. To meet the safety requirements of specific operating environments, some applications require bellows to have flame-retardant properties to reduce fire risk and improve system safety.

[0003] Currently, most common flame-retardant corrugated pipes are made from polymer materials with added flame retardants through extrusion molding, and their corrugated structure is usually a single layer. However, in practical applications, the flame-retardant effect of such corrugated pipes under high temperature or open flame conditions mainly relies on the chemical flame-retardant mechanism of the material itself. Once the outer layer material undergoes localized carbonization or melting, it may affect the integrity of the overall structure, and the pipe layers are prone to separation, thereby weakening its sustained flame-retardant ability and physical protection function. In addition, a single material system has certain limitations in balancing flexibility, weather resistance, and high-efficiency flame-retardant performance, making it difficult to meet the needs of complex working conditions. Therefore, it is necessary to develop a newer, more cost-effective technology that can meet multiple performance requirements under complex working conditions to solve the above problems. Utility Model Content

[0004] The purpose of this invention is to provide a flame-retardant corrugated pipe to address the problem in the prior art where the flame-retardant effect of corrugated pipes under high-temperature or open-flame conditions mainly relies on the chemical flame-retardant mechanism of the material itself. Once the outer layer material undergoes localized carbonization or melting, it may affect the integrity of the overall structure, making it easy for the pipe layers to separate, thereby weakening its sustained flame-retardant capability and physical protective function. Furthermore, single-material systems have certain limitations in balancing flexibility, weather resistance, and high-efficiency flame-retardant performance, making it difficult to meet the needs of complex working conditions.

[0005] This utility model provides the following technical solution: a flame-retardant corrugated pipe, comprising an inner tube, a middle barrier layer, and an outer sheath. The inner tube is further provided with crests and troughs. The middle barrier layer covers the outer layer of the inner tube, and the outer sheath covers the outer layer of the middle barrier layer. An adhesive layer is provided between the inner tube and the middle barrier layer, and the middle barrier layer is fixedly connected to the inner tube through the adhesive layer.

[0006] Preferably, the adhesive layer is an ethylene-vinyl acetate copolymer-based colloid.

[0007] Preferably, the intermediate barrier layer is further provided with folded portions at both ends, and the folded portions are wrapped around the ends of the inner tube.

[0008] Preferably, a raised structure is provided on the inner side of the outer sheath.

[0009] Preferably, the outer sheath is further provided with a flow guide groove, the cross-sectional shape of which is a trapezoidal shape that is wider at the top and narrower at the bottom.

[0010] Preferably, an antistatic coating is also provided inside the inner tube.

[0011] Preferably, the inner tube is made of a polyolefin elastomer material.

[0012] Preferably, the intermediate barrier layer is made of cross-woven glass fibers.

[0013] Preferably, the outer sheath is made of polyamide.

[0014] Preferably, the antistatic coating is conductive carbon black or fluororubber.

[0015] Compared with the prior art, the beneficial effects of this utility model are: 1. This utility model discloses a flame-retardant corrugated pipe, comprising an inner tube, a middle barrier layer, and an outer sheath. The inner tube has corrugations and troughs. The middle barrier layer covers the outer layer of the inner tube, and the outer sheath covers the outer layer of the middle barrier layer. An adhesive layer is provided between the inner tube and the middle barrier layer, and the middle barrier layer is fixedly connected to the inner tube via the adhesive layer. The corrugations and troughs ensure that the flame-retardant corrugated pipe does not experience localized stress concentration when bent. The middle barrier layer effectively maintains its physical barrier function at high temperatures, preventing high-temperature penetration. The adhesive layer forms a continuous and closed bonding section between the inner tube and the middle barrier layer, effectively preventing high-temperature penetration along the interlayer gaps. This allows the flame-retardant corrugated pipe to maintain structural stability in high-temperature environments, preventing layer-to-layer separation and enabling it to withstand complex working conditions at high temperatures.

[0016] 2. The flame-retardant corrugated pipe of this invention has an adhesive layer made of ethylene-vinyl acetate copolymer-based colloid. Ethylene-vinyl acetate copolymer-based colloid has good heat-sealing properties and can effectively prevent high temperatures from penetrating along the interlayer gaps.

[0017] 3. The flame-retardant corrugated pipe of this utility model has folded portions at both ends of the intermediate barrier layer, which are wrapped around the ends of the inner tube. The folded portions can effectively prevent the ends of the intermediate barrier layer from delaminating or warping under external force, ensuring the sealing and structural continuity of the ends of the flame-retardant corrugated pipe.

[0018] 4. The flame-retardant corrugated pipe of this utility model has a raised structure on the inner side of the outer sheath. The outer sheath forms a mechanical interlock with the intermediate barrier layer through the raised structure, which significantly improves the peeling ability between the outer sheath and the intermediate barrier layer.

[0019] 5. The flame-retardant corrugated pipe of this utility model is further provided with a guide groove on the outer sheath. The cross-sectional shape of the guide groove is a trapezoidal shape that is wider at the top and narrower at the bottom. The guide groove can guide the pyrolysis gas to escape in an orderly manner along the axial direction in high temperature or fire environments, avoiding local pressure accumulation that could cause the outer layer to bulge and rupture, and effectively maintaining the sealing performance and overall structural integrity of the flame-retardant corrugated pipe.

[0020] 6. The flame-retardant corrugated pipe of this utility model also has an antistatic coating inside the inner tube. This can effectively prevent the accumulation of static electricity due to friction during the transportation of flammable fluids or the laying of cables, avoid sparks caused by electrostatic discharge, and improve safety in use.

[0021] 7. The flame-retardant corrugated pipe of this utility model has an inner tube made of polyolefin elastomer material. Polyolefin elastomer material meets the mechanical strength requirements while retaining sufficient elastic deformation capacity.

[0022] 8. The flame-retardant corrugated pipe of this utility model has an intermediate barrier layer made of cross-woven glass fibers. Glass fibers have good tensile strength and are not prone to melting and dripping at high temperatures. The cross-weaving gives the intermediate barrier layer high strength, thus enabling the intermediate barrier layer to maintain its physical barrier function in high-temperature environments.

[0023] 9. The flame-retardant corrugated pipe of this utility model has an outer sheath made of polyamide. Polyamide has low thermal conductivity and can effectively block heat transfer.

[0024] 10. The flame-retardant corrugated pipe of this utility model has an antistatic coating made of conductive carbon black or fluororubber. Conductive carbon black or fluororubber has good antistatic properties. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a three-dimensional schematic diagram of the flame-retardant corrugated pipe of this utility model; Figure 2 This is a partial enlargement of the flame-retardant corrugated pipe of this utility model. Figure 1 ; Figure 3This is a partial enlargement of the flame-retardant corrugated pipe of this utility model. Figure 2 ; Figure 4 This is a cross-sectional view of the flame-retardant corrugated pipe of this utility model; Figure 5 This is a partial enlargement of the flame-retardant corrugated pipe of this utility model. Figure 3 ; Figure 6 This is a three-dimensional schematic diagram of the outer sheath of the flame-retardant corrugated pipe of this utility model; Figure 7 This is a partial enlargement of the flame-retardant corrugated pipe of this utility model. Figure 4 .

[0027] In the attached figures, 1 is the inner tube, 11 is the crest, 12 is the trough, and 13 is the antistatic coating; 2 is the intermediate barrier layer, 21 is the folded part; 3 is the outer sheath, 31 is the raised structure, 32 is the guide groove; and 4 is the adhesive layer. Detailed Implementation

[0028] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0029] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0030] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between the components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0031] In the description of this application, it should be understood that the terms "upper", "lower", "side", "front", "rear", etc., indicate the orientation or positional relationship based on the installation orientation or positional relationship, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0032] In the description of this application, it should be noted that the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0033] It should also be noted that in the embodiments of this application, the same reference numerals are used to represent the same component or part. For the same part in the embodiments of this application, the reference numerals may only be used to mark one part or component as an example. It should be understood that the reference numerals are also applicable to other identical parts or components.

[0034] Furthermore, in this application, the technical features described in an open-ended manner include both closed technical solutions composed of the listed features and open technical solutions that include the listed features.

[0035] To further understand the utility model content, features, and effects of this application, the following embodiments are provided, and detailed descriptions are given below in conjunction with the accompanying drawings: like Figure 1-7 As shown, the flame-retardant corrugated pipe includes an inner tube 1, a middle barrier layer 2, and an outer sheath 3. The inner tube 1 is further provided with crests 11 and troughs 12. The middle barrier layer 2 covers the outer layer of the inner tube 1, and the outer sheath 3 covers the outer layer of the middle barrier layer 2. An adhesive layer 4 is provided between the inner tube 1 and the middle barrier layer 2, and the middle barrier layer 2 is fixedly connected to the inner tube 1 through the adhesive layer 4. In this embodiment, the crests and troughs ensure that the inner tube does not experience localized stress concentration when bent. The middle barrier layer effectively maintains its physical barrier function at high temperatures, preventing high-temperature penetration. The adhesive layer forms a continuous and closed adhesive cross-section between the inner tube and the middle barrier layer, effectively preventing high-temperature penetration along the interlayer gaps. This allows the flame-retardant corrugated pipe to maintain structural stability even at high temperatures, preventing the layers from easily separating. The outer sheath provides protection on the outermost layer, blocking heat transfer. Of course, it is not limited to this. It can be any other material that can enable the flame-retardant corrugated pipe to maintain structural stability in high-temperature environments and prevent the layers from separating.

[0036] Specifically, adhesive layer 4 is an ethylene-vinyl acetate copolymer-based colloid. In this embodiment, the ethylene-vinyl acetate copolymer-based colloid has good heat-sealing properties, effectively preventing high-temperature penetration along the interlayer gaps while ensuring high bonding strength between the intermediate barrier layer and the inner tube. However, it is not limited to this; any other material capable of effectively preventing high-temperature penetration along the interlayer gaps while ensuring high bonding strength between the intermediate barrier layer and the inner tube can be used.

[0037] Specifically, such as Figure 5 As shown, folded portions 21 are provided at both ends of the intermediate barrier layer 2, and the folded portions 21 are wrapped around the ends of the inner tube 1. In this embodiment, the folded portions wrapped around the ends of the inner tube can effectively prevent the ends of the intermediate barrier layer from delaminating or warping under external force, ensuring the sealing and structural continuity of the ends of the flame-retardant corrugated pipe. Of course, it is not limited to this; other methods that can prevent the intermediate barrier layer from delaminating or warping can be used.

[0038] Specifically, such as Figure 6 , 7 As shown, a protruding structure 31 is provided on the inner side of the outer sheath 3. In this embodiment, the protruding structure is hemispherical in shape, and the outer sheath forms a mechanical interlocking structure with the intermediate barrier layer through the protruding structure, which significantly improves the peeling ability between the intermediate barrier layers of the outer sheath. Of course, it is not limited to this, and any other structure that can improve the peeling ability between the intermediate barrier layers of the outer sheath can be used.

[0039] Specifically, such as Figure 2 As shown, a flow channel 32 is also provided on the outer sheath 3. The cross-sectional shape of the flow channel 32 is a trapezoidal shape that is wider at the top and narrower at the bottom. In this embodiment, the flow channel is axially arranged on the surface of the outer sheath and extends through the length of the flame-retardant bellows. Eight flow channels are arranged around the circumference of the outer sheath. The flow channels can guide the pyrolysis gas to escape in an orderly manner along the axial direction in high temperature or fire environments, avoiding local pressure accumulation that could cause the outer layer to bulge and rupture. This can effectively maintain the sealing performance and overall structural integrity of the flame-retardant bellows. Of course, it is not limited to this; any other channel capable of guiding the pyrolysis gas to escape in an orderly manner along the axial direction in high temperature or fire environments can be used.

[0040] Specifically, such as Figure 3 As shown, an antistatic coating 13 is also provided inside the inner tube 1. In this embodiment, the antistatic coating can prevent the accumulation of static electricity due to friction during the transportation of flammable fluids or the laying of cables, avoiding sparks caused by electrostatic discharge and improving safety. Of course, it is not limited to this; it can be any coating that can prevent sparks caused by electrostatic discharge.

[0041] Specifically, the material of the inner tube 1 is a polyolefin elastomer. In this embodiment, the polyolefin elastomer material can be chosen so that the inner tube meets both mechanical strength requirements and retains sufficient elastic deformation capacity. Of course, it is not limited to this; it can be any other material that can meet both mechanical strength requirements and retain sufficient elastic deformation capacity.

[0042] Specifically, the intermediate barrier layer 2 is made of cross-woven glass fibers. In this embodiment, the diameter of the glass fibers is eight to twelve micrometers, and the weaving density is forty to sixty warp and weft yarns per square centimeter. After weaving, the porosity of the intermediate barrier layer is controlled between 30% and 50%. This design allows the intermediate barrier layer to maintain high tensile strength even at high temperatures and prevents it from melting and dripping. Thus, it can maintain its physical barrier function and prevent heat penetration even at high temperatures. Of course, it is not limited to this; it can be anything that maintains its physical barrier function and prevents heat penetration even at high temperatures.

[0043] Specifically, the outer sheath 3 is made of polyamide. In this embodiment, polyamide has low thermal conductivity, which can effectively block heat transfer. Of course, it is not limited to this; other materials that can effectively block heat transfer can also be used.

[0044] Specifically, the antistatic coating 13 is conductive carbon black or fluororubber. In this embodiment, the antistatic coating is conductive carbon black, or an antistatic coating is fluororubber, or an antistatic coating is a mixture of conductive carbon black and fluororubber. By selecting the materials, the inner tube has good antistatic properties, which can prevent static electricity buildup caused by friction during the transportation of flammable fluids or cable laying, avoid sparks caused by electrostatic discharge, and improve safety. Of course, it is not limited to this; it can be any material that can prevent sparks caused by electrostatic discharge.

[0045] Working principle: When the flame-retardant corrugated pipe is exposed to high temperature, the outer sheath has low thermal conductivity, which can isolate heat from being transferred inward. Even if the outer sheath cracks locally due to high temperature, the middle barrier layer can still maintain the overall shape and structure of the pipe, ensuring the thermal seal inside the pipe and preventing heat from penetrating into the internal cables or fluids. The inner tube, with the high elasticity of polyolefin elastomer, maintains structural stability under repeated bending or vibration conditions and is not easy to crack. The adhesive layer and the raised structure work together to ensure that the layers do not peel off under thermal cycling or mechanical stress. The flow channel effectively guides pyrolysis gas and avoids a sudden increase in internal pressure. The antistatic coating eliminates the risk of static electricity. The folded part ensures the integrity of the end.

[0046] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0047] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A flame-retardant corrugated pipe, characterized in that: It includes an inner tube (1), a middle barrier layer (2) and an outer sheath (3). The inner tube (1) is also provided with a peak (11) and a trough (12). The middle barrier layer (2) is covered and disposed on the outer layer of the inner tube (1). The outer sheath (3) is covered on the outer layer of the middle barrier layer (2). An adhesive layer (4) is provided between the inner tube (1) and the middle barrier layer (2). The middle barrier layer (2) is fixedly connected to the inner tube (1) through the adhesive layer (4).

2. The flame-retardant corrugated pipe according to claim 1, characterized in that: The adhesive layer (4) is an ethylene-vinyl acetate copolymer-based colloid.

3. The flame-retardant corrugated pipe according to claim 1 or 2, characterized in that: Folded portions (21) are provided at both ends of the intermediate barrier layer (2), and the folded portions (21) are wrapped around the ends of the inner tube (1).

4. The flame-retardant corrugated pipe according to claim 3, characterized in that: A protruding structure (31) is provided on the inner side of the outer sheath (3).

5. The flame-retardant corrugated pipe according to claim 4, characterized in that: The outer sheath (3) is also provided with a flow guide groove (32), and the cross-sectional shape of the flow guide groove (32) is a trapezoidal shape that is wider at the top and narrower at the bottom.

6. The flame-retardant corrugated pipe according to claim 4 or 5, characterized in that: An antistatic coating (13) is also provided inside the inner tube (1).

7. The flame-retardant corrugated pipe according to claim 6, characterized in that: The inner tube (1) is made of polyolefin elastomer material.

8. The flame-retardant corrugated pipe according to claim 7, characterized in that: The intermediate barrier layer (2) is made of cross-woven glass fibers.

9. The flame-retardant corrugated pipe according to claim 8, characterized in that: The outer sheath (3) is made of polyamide.

10. The flame-retardant corrugated pipe according to any one of claims 7-9, characterized in that: The antistatic coating (13) is conductive carbon black or fluororubber.

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