Fuel rubber tube with optimized gear-shaped surface structure and preparation method thereof

Abstract

The invention discloses a fuel oil rubber pipe with an optimized gear-shaped surface structure, which comprises a fluororubber inner pipe layer, a nitrile rubber middle layer and an ethylene acrylate rubber outer pipe layer which are sequentially arranged from inside to outside, and the thickness ratio of the fluororubber inner pipe layer to the nitrile rubber middle layer to the ethylene acrylate rubber outer pipe layer is 1: 1.5: 1; wherein a plurality of outer convex ribs are arranged on the surface of the ethylene acrylate rubber outer pipe layer in the circumferential direction, and the outer convex ribs are arranged in the axis direction of the ethylene acrylate rubber outer pipe layer. The invention further discloses a preparation method of the fuel rubber pipe with the optimized gear-shaped surface structure. Compared with the prior art, the safety problem caused by the fact that an existing fuel pipe with the smooth outer surface is inconvenient to fix and prone to abrasion is solved.

Description

Technical Field

[0001] The invention relates to the technical field of rubber tube vulcanization molding, and in particular to a fuel rubber tube with an optimized gear-shaped surface structure and a preparation method thereof. Background Art

[0002] Automobile fuel pipes are mainly used to provide gasoline circulation pipelines to provide power fuel for automobiles. In existing automobile fuel systems, the performance of fuel pipes has an important impact on the stability of the entire system.

[0003] Traditional fuel pipe designs often use a smooth outer surface structure. This design may cause the pipe body to wear or loosen due to factors such as friction and vibration during long-term use, thereby affecting safety. Summary of the invention

[0004] The purpose of the present invention is to provide a fuel rubber hose with an optimized gear-shaped surface structure and a preparation method thereof, so as to solve the safety problems caused by the inconvenience of fixing and easy wear of the existing fuel hose with a smooth outer surface.

[0005] In order to achieve the above-mentioned object, on the one hand, the present invention discloses a fuel rubber hose with an optimized gear-shaped surface structure, comprising a fluororubber inner tube layer, a nitrile rubber middle layer and an ethylene acrylate rubber outer tube layer arranged in sequence from the inside to the outside, wherein the thickness ratio of the fluororubber inner tube layer, the nitrile rubber middle layer and the ethylene acrylate rubber outer tube layer is 1:1.5:1;

[0006] The surface of the ethylene acrylate rubber outer tube layer is provided with a plurality of circumferentially arranged external convex ribs, and the external convex ribs are arranged along the axial direction of the ethylene acrylate rubber outer tube layer.

[0007] On the other hand, the present invention also discloses a method for preparing the fuel rubber hose having the optimized gear-shaped surface structure as described above, comprising the following steps:

[0008] S1, inner tube layer mixing: taking raw material components of the fluororubber inner tube layer, adding them into the first internal mixer for melt blending, and rolling the discharged materials into sheets through an open mixer and cooling them to obtain an inner tube layer film;

[0009] S2, middle layer mixing: taking the raw material components of the nitrile rubber middle layer, adding them into the second internal mixer for melt blending, and rolling them into sheets through an open mixer and cooling them after discharge to obtain the middle layer rubber sheet;

[0010] S3, outer tube layer mixing: taking the raw material components of the ethylene acrylate rubber outer tube layer, adding them into the third internal mixer for melt blending, and rolling them into sheets through an open mixer and cooling them after discharge to obtain the outer tube layer film;

[0011] S4, co-extrusion: the inner tube layer film, the middle layer film and the outer tube layer film are respectively fed into three extruders, and mixed and extruded through the same three-layer composite die head to obtain a fuel tube blank;

[0012] S5. Vulcanization: The fuel pipe blank is sent to the vulcanization tank for molding and vulcanization. After being taken out and cooled, the finished fuel pipe is obtained.

[0013] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0014] 1. In the present invention, the fuel rubber hose adopts a multi-layer structure formed by one-step extrusion. The outer convex ribs on the surface of the outer ethylene acrylate rubber outer tube layer make the cross section of the fuel rubber hose present a gear-like structure. On the one hand, when the surface of the fuel rubber hose is worn, the outer convex ribs are worn first, which can prevent the fuel rubber hose from being damaged and leaking. On the other hand, the surface roughness of the fuel rubber hose can be improved, which is convenient for bundling and fixing. Therefore, the fuel rubber hose with an optimized gear-like surface structure can effectively solve the safety problems caused by the inconvenience of fixing and easy wear of the existing fuel hose with a smooth outer surface.

[0015] 2. In the present invention, the fuel rubber tube is extruded in one step, and the nitrile rubber middle layer between the fluororubber inner tube layer and the ethylene acrylate rubber outer tube layer can effectively improve the bonding quality of the three-layer material because NBR rubber has excellent oil resistance and high wear resistance, heat resistance and strong adhesion. At the same time, the thickness ratio of the fluororubber inner tube layer, the nitrile rubber middle layer and the ethylene acrylate rubber outer tube layer is 1:1.5:1, which is convenient for the bonding of the fluororubber inner tube layer, the ethylene acrylate rubber outer tube layer and the nitrile rubber middle layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 The schematic diagram of the structure of a fuel rubber hose with an optimized gear-shaped surface structure.

[0018] Figure 2 for Figure 1 A partial enlarged view of point A in the middle.

[0019] Legend:

[0020] 1. Fluorine rubber inner tube layer; 11. Second self-fastening protrusion; 2. Nitrile rubber middle layer; 3. Ethylene acrylate rubber outer tube layer; 31. External convex rib; 32. First self-fastening protrusion. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0024] In the description of the embodiments of the present invention, it should be noted that the terms "upper", "inner", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0025] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] Example 1

[0027] On the one hand, the present invention provides a fuel rubber hose with an optimized gear-shaped surface structure, comprising a fluororubber inner tube layer 1, a nitrile rubber middle layer 2 and an ethylene acrylate rubber outer tube layer 3 arranged in sequence from the inside to the outside, wherein the thickness ratio of the fluororubber inner tube layer 1, the nitrile rubber middle layer 2 and the ethylene acrylate rubber outer tube layer 3 is 1:1.5:1;

[0028] The surface of the ethylene acrylate rubber outer tube layer 3 is provided with a plurality of circumferentially arranged external ribs 31 , and the external ribs 31 are arranged along the axial direction of the ethylene acrylate rubber outer tube layer 3 .

[0029] The fluororubber inner tube layer 1 comprises the following components in parts by weight: 100 parts of peroxide fluororubber, 20 parts of fluoroplastic, 2 parts of vulcanizing agent, and 2 parts of accelerator.

[0030] The nitrile rubber intermediate layer 2 comprises the following components in parts by weight: 100 parts of nitrile rubber, 50 parts of polybutene, 0.1 parts of vulcanizing agent, and 0.15 parts of antioxidant.

[0031] The ethylene acrylate rubber outer tube layer 3 includes the following components in parts by weight: 120 parts of AEM rubber, 60 parts of carbon black N990, 7 parts of ether plasticizer, 0.6 parts of mold release agent, 3 parts of antioxidant, 1.6 parts of di-o-tolyguanidine, and 1.5 parts of peroxide DCPO.

[0032] On the other hand, the present invention provides a method for preparing the above-mentioned fuel rubber hose with an optimized gear-shaped surface structure, comprising the following steps:

[0033] S1, inner tube layer mixing: taking the raw material components of the fluororubber inner tube layer 1, adding them into the first internal mixer for melt blending, and rolling them into sheets through an open mixer and cooling them after discharge to obtain the inner tube layer film;

[0034] S2, intermediate layer mixing: taking the raw material components of the nitrile rubber intermediate layer 2, adding them into the second internal mixer for melt blending, and rolling them into sheets through an open mixer and cooling them after discharge to obtain an intermediate layer rubber sheet;

[0035] S3, outer tube layer mixing: taking the raw material components of the ethylene acrylate rubber outer tube layer 3, adding them into the third internal mixer for melt blending, and rolling them into sheets through an open mixer and cooling them to obtain an outer tube layer film;

[0036] S4, co-extrusion: the inner tube layer film, the middle layer film and the outer tube layer film are respectively fed into three extruders, and mixed and extruded through the same three-layer composite die head to obtain a fuel tube blank;

[0037] S5. Vulcanization: The fuel pipe blank is sent to the vulcanization tank for molding and vulcanization. After being taken out and cooled, the finished fuel pipe is obtained.

[0038] Working principle: The fuel rubber hose is extruded in one step, with a nitrile rubber middle layer 2 between the fluororubber inner tube layer 1 and the ethylene acrylate rubber outer tube layer 3. Since NBR rubber has excellent oil resistance and high wear resistance, heat resistance and strong adhesion, the bonding quality of the three layers of materials can be effectively improved. At the same time, the thickness ratio of the fluororubber inner tube layer 1, the nitrile rubber middle layer 2 and the ethylene acrylate rubber outer tube layer 3 is 1:1.5:1, which is convenient for the fluororubber inner tube layer 1, the ethylene acrylate rubber outer tube layer 3 and the nitrile rubber middle layer 2 to be bonded.

[0039] The fuel rubber hose adopts a multi-layer structure formed by one-step extrusion. Among them, the outer convex ribs on the surface of the outer ethylene acrylate rubber outer tube layer make the cross-section of the fuel rubber hose present a gear-like structure. On the one hand, when the surface of the fuel rubber hose is worn, the outer convex ribs are worn first, which can prevent the fuel rubber hose from being damaged or leaking. On the other hand, the surface roughness of the fuel rubber hose can be increased, which is convenient for bundling and fixing. Therefore, the fuel rubber hose with an optimized gear-like surface structure can effectively solve the safety problems caused by the inconvenience of fixing and easy wear of existing fuel pipes with smooth outer surfaces. The fluororubber inner tube layer 1 can effectively prevent the fuel or fuel vapor in the fuel rubber hose from penetrating out of the pipeline, thereby avoiding pollution. The ethylene acrylate rubber outer tube layer 3 effectively prevents the fuel rubber hose from being damaged due to the good environmental stress cracking resistance of the AEM rubber.

[0040] Example 2

[0041] On the one hand, the present invention provides a fuel rubber hose with an optimized gear-shaped surface structure, comprising a fluororubber inner tube layer 1, a nitrile rubber middle layer 2 and an ethylene acrylate rubber outer tube layer 3 arranged in sequence from the inside to the outside, wherein the thickness ratio of the fluororubber inner tube layer 1, the nitrile rubber middle layer 2 and the ethylene acrylate rubber outer tube layer 3 is 1:1.5:1;

[0042] The surface of the ethylene acrylate rubber outer tube layer 3 is provided with a plurality of circumferentially arranged external ribs 31 , and the external ribs 31 are arranged along the axial direction of the ethylene acrylate rubber outer tube layer 3 .

[0043] The fluororubber inner tube layer 1 comprises the following components in parts by weight: 100 parts of peroxide fluororubber, 20 parts of fluoroplastic, 2 parts of vulcanizing agent, and 2 parts of accelerator.

[0044] The nitrile rubber intermediate layer 2 comprises the following components in parts by weight: 100 parts of nitrile rubber, 50 parts of polybutene, 0.1 parts of vulcanizing agent, and 0.15 parts of antioxidant.

[0045] The ethylene acrylate rubber outer tube layer 3 comprises the following components in parts by weight: 100 parts of AEM rubber, 40 parts of carbon black N990, 5 parts of ether plasticizer, 0.5 parts of release agent, 1 part of antioxidant, 1.5 parts of di-o-tolylguanidine, and 0.3 parts of peroxide DCP.

[0046] On the other hand, the present invention provides a method for preparing the above-mentioned fuel rubber hose with an optimized gear-shaped surface structure, comprising the following steps:

[0047] S1, inner tube layer mixing: taking the raw material components of the fluororubber inner tube layer 1, adding them into the first internal mixer for melt blending, and rolling them into sheets through an open mixer and cooling them after discharge to obtain the inner tube layer film;

[0048] S2, intermediate layer mixing: taking the raw material components of the nitrile rubber intermediate layer 2, adding them into the second internal mixer for melt blending, and rolling them into sheets through an open mixer and cooling them after discharge to obtain an intermediate layer rubber sheet;

[0049] S3, outer tube layer mixing: taking the raw material components of the ethylene acrylate rubber outer tube layer 3, adding them into the third internal mixer for melt blending, and rolling them into sheets through an open mixer and cooling them to obtain an outer tube layer film;

[0050] S4, co-extrusion: the inner tube layer film, the middle layer film and the outer tube layer film are respectively fed into three extruders, and mixed and extruded through the same three-layer composite die head to obtain a fuel tube blank;

[0051] S5. Vulcanization: The fuel pipe blank is sent to the vulcanization tank for molding and vulcanization. After being taken out and cooled, the finished fuel pipe is obtained.

[0052] Example 3

[0053] On the one hand, the present invention provides a fuel rubber hose with an optimized gear-shaped surface structure, comprising a fluororubber inner tube layer 1, a nitrile rubber middle layer 2 and an ethylene acrylate rubber outer tube layer 3 arranged in sequence from the inside to the outside, wherein the thickness ratio of the fluororubber inner tube layer 1, the nitrile rubber middle layer 2 and the ethylene acrylate rubber outer tube layer 3 is 1:1.5:1;

[0054] The surface of the ethylene acrylate rubber outer tube layer 3 is provided with a plurality of circumferentially arranged external ribs 31 , and the external ribs 31 are arranged along the axial direction of the ethylene acrylate rubber outer tube layer 3 .

[0055] The fluororubber inner tube layer 1 comprises the following components in parts by weight: 120 parts of peroxide fluororubber, 30 parts of fluoroplastic, 2 parts of vulcanizing agent, and 2 parts of accelerator.

[0056] The nitrile rubber intermediate layer 2 comprises the following components in parts by weight: 100 parts of nitrile rubber, 50 parts of polybutene, 0.1 parts of vulcanizing agent, and 0.15 parts of antioxidant.

[0057] The ethylene acrylate rubber outer tube layer 3 comprises the following components in parts by weight: 120 parts of AEM rubber, 60 parts of carbon black N990, 7 parts of ether plasticizer, 0.6 parts of release agent, 3 parts of antioxidant, 1.6 parts of di-o-tolylguanidine, and 0.5 parts of peroxide DCP.

[0058] On the other hand, the present invention provides a method for preparing the above-mentioned fuel rubber hose with an optimized gear-shaped surface structure, comprising the following steps:

[0059] S1, inner tube layer mixing: taking the raw material components of the fluororubber inner tube layer 1, adding them into the first internal mixer for melt blending, and rolling them into sheets through an open mixer and cooling them after discharge to obtain the inner tube layer film;

[0060] S2, intermediate layer mixing: taking the raw material components of the nitrile rubber intermediate layer 2, adding them into the second internal mixer for melt blending, and rolling them into sheets through an open mixer and cooling them after discharge to obtain an intermediate layer rubber sheet;

[0061] S3, outer tube layer mixing: taking the raw material components of the ethylene acrylate rubber outer tube layer 3, adding them into the third internal mixer for melt blending, and rolling them into sheets through an open mixer and cooling them to obtain an outer tube layer film;

[0062] S4, co-extrusion: the inner tube layer film, the middle layer film and the outer tube layer film are respectively fed into three extruders, and mixed and extruded through the same three-layer composite die head to obtain a fuel tube blank;

[0063] S5. Vulcanization: The fuel pipe blank is sent to the vulcanization tank for molding and vulcanization. After being taken out and cooled, the finished fuel pipe is obtained.

[0064] Example 4

[0065] On the one hand, the present invention provides a fuel rubber hose with an optimized gear-shaped surface structure, comprising a fluororubber inner tube layer 1, a nitrile rubber middle layer 2 and an ethylene acrylate rubber outer tube layer 3 arranged in sequence from the inside to the outside, wherein the thickness ratio of the fluororubber inner tube layer 1, the nitrile rubber middle layer 2 and the ethylene acrylate rubber outer tube layer 3 is 1:1.5:1;

[0066] The surface of the ethylene acrylate rubber outer tube layer 3 is provided with a plurality of circumferentially arranged external ribs 31 , and the external ribs 31 are arranged along the axial direction of the ethylene acrylate rubber outer tube layer 3 .

[0067] The fluororubber inner tube layer 1 comprises the following components in parts by weight: 120 parts of peroxide fluororubber, 30 parts of fluoroplastic, 2 parts of vulcanizing agent, and 2 parts of accelerator.

[0068] The nitrile rubber intermediate layer 2 comprises the following components in parts by weight: 110 parts of nitrile rubber, 60 parts of polybutene, 0.15 parts of vulcanizing agent, and 0.18 parts of antioxidant.

[0069] The ethylene acrylate rubber outer tube layer 3 includes the following components in parts by weight: 120 parts of AEM rubber, 60 parts of carbon black N990, 7 parts of ether plasticizer, 0.6 parts of mold release agent, 3 parts of antioxidant, 1.6 parts of di-o-tolyguanidine, and 1.5 parts of peroxide DCPO.

[0070] On the other hand, the present invention provides a method for preparing the above-mentioned fuel rubber hose with an optimized gear-shaped surface structure, comprising the following steps:

[0071] S1, inner tube layer mixing: taking the raw material components of the fluororubber inner tube layer 1, adding them into the first internal mixer for melt blending, and rolling them into sheets through an open mixer and cooling them after discharge to obtain the inner tube layer film;

[0072] S2, intermediate layer mixing: taking the raw material components of the nitrile rubber intermediate layer 2, adding them into the second internal mixer for melt blending, and rolling them into sheets through an open mixer and cooling them after discharge to obtain an intermediate layer rubber sheet;

[0073] S3, outer tube layer mixing: taking the raw material components of the ethylene acrylate rubber outer tube layer 3, adding them into the third internal mixer for melt blending, and rolling them into sheets through an open mixer and cooling them to obtain an outer tube layer film;

[0074] S4, co-extrusion: the inner tube layer film, the middle layer film and the outer tube layer film are respectively fed into three extruders, and mixed and extruded through the same three-layer composite die head to obtain a fuel tube blank;

[0075] S5. Vulcanization: The fuel pipe blank is sent to the vulcanization tank for molding and vulcanization. After being taken out and cooled, the finished fuel pipe is obtained.

[0076] Example 5

[0077] This embodiment further provides the following improved technical solutions based on the above embodiment: Figure 1-2 In step S4, the three-layer composite die is a three-layer self-fastening composite co-extrusion die. When the inner tube layer film, the middle layer film and the outer tube layer film are extruded by the extruder, they are fed from the three feed ports of the three-layer self-fastening composite co-extrusion die respectively. In the extruded fuel pipe blank, a first self-fastening protrusion 32 is formed on the inner wall of the ethylene acrylate rubber outer tube layer 3, a first self-fastening groove whose shape matches the first self-fastening protrusion 32 is provided on the outer wall of the nitrile rubber middle layer 2, a second self-fastening protrusion 11 is formed on the outer wall of the fluororubber inner tube layer 1, and a second self-fastening groove whose shape matches the second self-fastening protrusion 11 is provided on the inner wall of the nitrile rubber middle layer 2, thereby further improving the bonding quality of the fluororubber inner tube layer 1, the nitrile rubber middle layer 2 and the ethylene acrylate rubber outer tube layer 3.

[0078] The three materials are fed separately from three feed ports, the materials are merged, and extruded through a self-fastening die and a self-fastening mandrel to form a three-layer self-fastening composite pipe.

[0079] Specifically, the outer tube layer rubber material enters the outer layer material flow channel and is formed into an outer layer tube through a self-fastening die; the middle layer rubber material enters the middle layer material flow channel and is extruded to form a middle layer tube; the inner tube layer rubber material enters the inner layer material flow channel and is formed into an inner layer tube.

[0080] Example 6

[0081] This embodiment further provides the following improved technical solutions based on the above embodiments: the first self-fastening protrusions 32 and the external convex ribs 31 are staggered to effectively ensure the thickness of the ethylene acrylate rubber outer tube layer 3 and avoid deformation and rupture of the ethylene acrylate rubber outer tube layer 3.

[0082] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A fuel rubber hose with an optimized gear-shaped surface structure, characterized in that: It comprises a fluororubber inner tube layer, a nitrile rubber middle layer and an ethylene acrylate rubber outer tube layer which are arranged in sequence from the inside to the outside, and the thickness ratio of the fluororubber inner tube layer, the nitrile rubber middle layer and the ethylene acrylate rubber outer tube layer is 1:1.5:1; Wherein, a plurality of circumferentially arranged external convex ribs are provided on the surface of the ethylene acrylate rubber outer tube layer, and the external convex ribs are arranged along the axial direction of the ethylene acrylate rubber outer tube layer.

2. The fuel rubber hose with an optimized gear-shaped surface structure according to claim 1, characterized in that: The fluororubber inner tube layer comprises the following components in parts by weight: 100-120 parts of peroxide fluororubber, 10-40 parts of fluoroplastic, 0.5-3 parts of vulcanizing agent, and 0.5-3 parts of accelerator.

3. The fuel rubber hose with an optimized gear-shaped surface structure according to claim 1, characterized in that: The nitrile rubber middle layer comprises the following components in parts by weight: 90 to 110 parts of nitrile rubber, 40 to 70 parts of polybutene, 0.1 to 0.7 parts of vulcanizing agent, and 0.1 to 0.2 parts of antioxidant.

4. The fuel rubber hose with an optimized gear-shaped surface structure according to claim 1, characterized in that: The ethylene acrylate rubber outer tube layer comprises the following components in parts by weight: 100-120 parts of AEM rubber, 30-80 parts of carbon black N990, 5-15 parts of ether plasticizer, 0.5-1.0 parts of release agent, 1-3 parts of antioxidant, 1.5-2.0 parts of di-o-tolylguanidine, and 3-1 parts of peroxide DCPO.

5. A method for preparing a fuel rubber hose having an optimized gear-shaped surface structure as claimed in any one of claims 1 to 4, characterized in that: The following steps are involved: S1, inner tube layer mixing: taking raw material components of the fluororubber inner tube layer, adding them into the first internal mixer for melt blending, and rolling the discharged materials into sheets through an open mixer and cooling them to obtain an inner tube layer film; S2, middle layer mixing: taking the raw material components of the nitrile rubber middle layer, adding them into the second internal mixer for melt blending, and rolling them into sheets through an open mixer and cooling them after discharge to obtain the middle layer rubber sheet; S3, outer tube layer mixing: taking the raw material components of the ethylene acrylate rubber outer tube layer, adding them into the third internal mixer for melt blending, and rolling them into sheets through an open mixer and cooling them after discharge to obtain the outer tube layer film; S4, co-extrusion: the inner tube layer film, the middle layer film and the outer tube layer film are respectively fed into three extruders, and mixed and extruded through the same three-layer composite die head to obtain a fuel tube blank; S5. Vulcanization: The fuel pipe blank is sent to the vulcanization tank for molding and vulcanization. After being taken out and cooled, the finished fuel pipe is obtained.

6. The method for preparing a fuel rubber hose having an optimized gear-shaped surface structure according to claim 5, characterized in that: In the step S4, the three-layer composite die is a three-layer self-fastening composite co-extrusion die. When the inner tube layer film, the middle layer film and the outer tube layer film are extruded by the extruder, they are fed from the three feed ports of the three-layer self-fastening composite co-extrusion die respectively. In the extruded fuel pipe blank, a first self-fastening protrusion is formed on the inner wall of the ethylene acrylate rubber outer tube layer, a first self-fastening groove whose shape matches the first self-fastening protrusion is provided on the outer wall of the nitrile rubber middle layer, a second self-fastening protrusion is formed on the outer wall of the fluororubber inner tube layer, and a second self-fastening groove whose shape matches the second self-fastening protrusion is provided on the inner wall of the nitrile rubber middle layer.

7. The method for preparing a fuel rubber hose having an optimized gear-shaped surface structure according to claim 6, characterized in that: The first self-locking protrusion and the external convex rib are arranged in a staggered manner.

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