Multi-layer composite fuel pipe

Abstract

The utility model discloses a multi-layer composite fuel pipe, which relates to the technical field of fuel pipes and comprises a high-temperature resistant layer, a barrier layer and an inner barrier layer which are sequentially arranged from outside to inside, and every two adjacent layers are bonded through a bonding layer or directly bonded. The fuel pipe is formed by compositing the high-temperature-resistant layer and the double-blocking layer, has the advantages of being resistant to impact, corrosion and permeation, high in high-low temperature alternating resistance, low in cost and free of oligomer precipitation, the double-blocking layer has the double-blocking effect on oil gas, fuel can be effectively prevented from permeating to the outside of the pipe, the national standard requirement is met, and the fuel pipe is suitable for large-scale popularization and application. And small molecule additives and low polymers in the outer layer material can be effectively prevented from entering the pipe to form precipitates to block the pipeline.

Description

Technical Field

[0001] The utility model relates to the technical field of fuel pipes, in particular to a multi-layer composite fuel pipe. Background Art

[0002] Currently, the fuel pipes used in passenger vehicles are mostly single-layer or multi-layer polymer pipes. Their wall structure strength, impact resistance, corrosion resistance, impermeability, high and low temperature resistance, low precipitation, etc. cannot meet the requirements of current high-performance vehicles. They are prone to deformation when colliding with objects such as stones, and are prone to aging under high and low temperature alternating use due to seasons or long-term operation of the engine. Moreover, they cannot effectively prevent the penetration of fuel and its evaporates, making it difficult to meet the requirements of higher impermeability international standards. It is easy to cause environmental pollution due to the penetration and volatilization of fuel and its evaporates, and the service life of the pipe body is relatively low, which is not conducive to improving the overall performance of the vehicle.

[0003] Although the current multi-layer pipes are effectively blocked using ethylene-vinyl alcohol copolymer (EVOH), the EVOH material is relatively special. Its processing temperature is low, and when co-extruded with other materials, it is extremely easy to degrade due to temperature during the processing, resulting in a decline in mechanical properties. At the same time, the inner barrier layer of the pipe directly contacts the fuel, and a lot of oligomers and plasticizers will precipitate. The increase in precipitates is likely to cause pipeline blockage and affect fuel supply. Therefore, vehicles with higher requirements for the fuel system need to improve the existing fuel pipe structure to overcome the above defects. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a multi-layer composite fuel pipe to solve the problems existing in the above-mentioned prior art, so that the fuel pipe has a double-barrier effect on oil and gas and is resistant to high temperatures.

[0005] To achieve the above purpose, the utility model provides the following solutions:

[0006] The utility model provides a multi-layer composite fuel pipe, which includes a high-temperature resistant layer, a barrier layer, and an inner barrier layer arranged in sequence from outside to inside. Adjacent two layers are bonded through an adhesive layer or directly bonded.

[0007] Preferably, the high-temperature resistant layer includes any one of polyphthalamide, polyphenylene sulfide, and polyamide.

[0008] Preferably, the barrier layer includes any one of ethylene-vinyl alcohol copolymer, polyvinylidene fluoride, ethylene-tetrafluoroethylene polymer, and polyamide engineering plastics.

[0009] Preferably, the inner barrier layer includes any one of polyvinylidene fluoride materials, ethylene-tetrafluoroethylene polymers, and polyamide engineering plastics.

[0010] Preferably, the adhesive layer comprises an adhesive.

[0011] Preferably, the thickness of the high-temperature resistant layer is 0.4 mm - 0.5 mm.

[0012] Preferably, the thickness of the barrier layer is 0.1 mm - 0.2 mm.

[0013] Preferably, the thickness of the inner barrier layer is 0.1 mm - 0.2 mm.

[0014] Preferably, the thickness of the adhesive layer is 0.1 mm - 0.2 mm.

[0015] Preferably, the wall thickness of the multi-layer composite fuel pipe is not greater than 2 mm, and it is integrally formed by a co-extrusion process.

[0016] The present utility model has achieved the following technical effects compared with the prior art:

[0017] The fuel pipe of the present utility model is multi-layer composite of a high-temperature resistant layer and a double barrier layer, and has the characteristics of strong impact resistance, corrosion resistance, penetration resistance, high and low temperature alternating resistance, low cost and no oligomer precipitation. The double barrier layer has a double barrier effect on oil and gas, can effectively prevent fuel from penetrating to the outside of the pipe, meets the national standard requirements, and can also effectively prevent small molecule additives and oligomers in the outer layer material from entering the pipe to form precipitates and block the pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is the first structural schematic diagram of the multi-layer composite fuel pipe in the embodiment of the present utility model;

[0020] Figure 2 It is the second structural schematic diagram of the multi-layer composite fuel pipe in the embodiment of the present utility model;

[0021] Figure 3 It is the third structural schematic diagram of the multi-layer composite fuel pipe in the embodiment of the present utility model;

[0022] Figure 4 It is the fourth structural schematic diagram of the multi-layer composite fuel pipe in the embodiment of the present utility model;

[0023] In the figure: 1 - high-temperature resistant layer, 2 - barrier layer, 3 - inner barrier layer, 4 - adhesive layer. Detailed implementation manners

[0024] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

[0025] The purpose of the present utility model is to provide a multi-layer composite fuel pipe to solve the problems existing in the prior art, so that the fuel pipe has a double-layer barrier effect on oil and gas and is resistant to high temperatures.

[0026] In order to make the above objects, features and advantages of the present utility model more obvious and understandable, the present utility model will be further described in detail below in conjunction with the drawings and specific implementation manners.

[0027] Embodiment 1

[0028] As shown in Figures 1 to 4 , in this embodiment, a multi-layer composite fuel pipe is provided, which includes a high-temperature resistant layer 1, a barrier layer 2, and an inner barrier layer 3 arranged in sequence from outside to inside. The adjacent two structural layers are bonded through an adhesive layer 4 or directly bonded (by material modification). The pipe wall in this embodiment adopts a composite layer structure. The outermost layer is the high-temperature resistant layer 1, and the material can be selected from PPA / PPS / PA612 resin. This material has excellent physical, thermal and electrical properties, long-term high-temperature resistance performance, excellent chemical resistance, high heat distortion temperature (HDT), high flexural modulus and other properties, and the highest tolerance temperature reaches 130 °C. It can be used for the oil pipeline in the long-term high-temperature environment around the engine, and can also be used as a fuel vapor pipeline; the middle layer is the barrier layer 2, and the material can be selected from EVOH / PVDF / ETFE / PA9T. Its remarkable characteristics are excellent barrier properties to fuel and excellent processability. In addition, its transparency, gloss, mechanical strength, stretchability, wear resistance, cold resistance and surface strength are all very excellent; the innermost layer is also a barrier layer, and the material can be selected from PVDF / ETFE / PA9T. It has good chemical corrosion resistance, high temperature resistance, oxidation resistance, weather resistance, radiation resistance, and also has special properties such as piezoelectricity, dielectricity, and pyroelectricity. The double-layer barrier layer design of this pipe has a double-layer barrier effect on oil and gas, can effectively prevent fuel from penetrating to the outside of the pipe, meet the national standard requirements; and avoid small molecule additives and oligomers in the outer layer material from entering the inside of the pipe to form precipitates and block the pipeline.

[0029] As an alternative solution, in this embodiment, the high-temperature resistant layer 1 includes any one of polyphthalamide or polyphenylene sulfide and polyamide.

[0030] As an alternative, in this embodiment, the barrier layer 2 comprises any one of ethylene-vinyl alcohol copolymer, polyvinylidene fluoride, ethylene-tetrafluoroethylene polymer, and polyamide engineering plastics.

[0031] As an alternative, in this embodiment, the inner barrier layer 3 comprises any one of polyvinylidene fluoride material, ethylene-tetrafluoroethylene polymer, and polyamide engineering plastics. The design of the double-layer barrier can effectively prevent small molecule additives and oligomers in the outer layer material, or external impurities and oxygen from entering the inside of the tube, and also prevent oil and gas molecules from leaking out.

[0032] As an alternative, in this embodiment, the adhesive layer 4 comprises an adhesive, which can be an epoxy resin adhesive, a cyanate ester adhesive, an acid anhydride adhesive, a polyurethane adhesive, a polyamide adhesive, and a hot melt adhesive.

[0033] As an alternative, in this embodiment, the thickness of the high-temperature resistant layer 1 is 0.4 mm - 0.5 mm.

[0034] As an alternative, in this embodiment, the thickness of the barrier layer 2 is 0.1 mm - 0.2 mm.

[0035] As an alternative, in this embodiment, the thickness of the inner barrier layer 3 is 0.1 mm - 0.2 mm.

[0036] As an alternative, in this embodiment, the thickness of the adhesive layer 4 is 0.1 mm - 0.2 mm.

[0037] As an alternative, in this embodiment, the wall thickness of the multi-layer composite fuel pipe is not greater than 2 mm, and it is formed by co-extrusion process at one time. This not only saves costs, but also realizes environmental protection and energy conservation, and has great application potential.

[0038] The pipe structure of this embodiment realizes the combined application of multiple materials, and can effectively achieve the functions of multiple materials. For example, there are 3 material options for the high-temperature resistant layer 1 material, 4 material options for the middle barrier layer 2, and 3 material options for the inner barrier layer 3. Multiple materials can be selected and arranged in combination, and can meet the pipeline requirements under different conditions according to needs; at the same time, the material of the high-temperature resistant layer 1 also has excellent impact resistance, wear resistance, ozone resistance, aging resistance, light resistance and many other excellent properties. Among them, the materials of each layer can be reasonably matched according to requirements. If the raw materials of the high-temperature resistant layer 1 and the two barrier layers are all selected as low-cost materials, the production cost can be reduced; when used as a vehicle fuel pipe, the overall performance of the vehicle can be enhanced and improved. In addition to being used as a vehicle fuel vapor pipeline, it can also be used as a conveying pipeline for other liquids and gases.

[0039] Embodiment 2

[0040] AsFigure 1 As shown, the structural layer of this embodiment includes a high-temperature resistant layer 1, an adhesive layer 4, a barrier layer 2, an adhesive layer 4, and an inner barrier layer 3.

[0041] Among them, the material of the high-temperature resistant layer 1 is polyphthalamide (PPA) or polyphenylene sulfide (PPS) or polyamide 612 (PA612). The middle barrier layer 2 is made of ethylene-vinyl alcohol copolymer (EVOH) or polyvinylidene fluoride (PVDF) or ethylene-tetrafluoroethylene polymer (ETFE) or polyamide engineering plastics (PA9T). The inner barrier layer 3 is made of polyvinylidene fluoride material (PVDF) or ethylene-tetrafluoroethylene polymer (ETFE) or polyamide engineering plastics PA9T.

[0042] Embodiment Three

[0043] As Figure 2 shown, the structural layer of this embodiment includes a high-temperature resistant layer 1, an adhesive layer 4, a barrier layer 2, and an inner barrier layer 3. The two barrier layers in this embodiment can achieve direct adhesion through the improvement of material properties, but the relative cost will increase at the same time.

[0044] Embodiment Four

[0045] As Figure 3 shown, the structural layer of this embodiment includes a high-temperature resistant layer 1, a barrier layer 2, an adhesive layer 4, and an inner barrier layer 3.

[0046] In this embodiment, the high-temperature resistant layer 1 and the barrier layer 2 can achieve direct adhesion between the material of the high-temperature resistant layer 1 and the middle barrier layer 2 through the improvement of material properties, but the relative cost will increase at the same time.

[0047] Embodiment Five

[0048] As Figure 4 shown, the structural layer of this embodiment includes a high-temperature resistant layer 1, a barrier layer 2, and an inner barrier layer 3.

[0049] In this embodiment, the high-temperature resistant layer 1 and the barrier layer 2, and between the two barrier layers can all achieve direct adhesion through the improvement of material properties, but the relative cost will increase.

[0050] In the present utility model, specific examples are used to elaborate on the principle and implementation manner of the present utility model. The descriptions of the above embodiments are only used to help understand the method and its core idea of the present utility model; at the same time, for those of ordinary skill in the art, according to the idea of the present utility model, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present utility model.

Claims

1. A multi-layer composite fuel pipe, characterized in that: It includes a high-temperature resistant layer, a barrier layer and an inner barrier layer which are arranged from outside to inside in sequence, and the adjacent two structural layers are bonded by an adhesive layer or directly bonded; the high-temperature resistant layer includes any one of polyphthalamide or polyphenylene sulfide and polyamide; the inner barrier layer includes any one of polyvinylidene fluoride material, ethylene-tetrafluoroethylene polymer and polyamide engineering plastics; the adhesive layer includes an adhesive.

2. The multi-layer composite fuel pipe according to claim 1, wherein: The barrier layer includes any one of ethylene-vinyl alcohol copolymer, polyvinylidene difluoride, ethylene-tetrafluoroethylene polymer and polyamide engineering plastics.

3. The multi-layer composite fuel pipe according to claim 1, characterized in that: The thickness of the high-temperature resistant layer is 0.4 mm - 0.5 mm.

4. The multi-layer composite fuel pipe according to claim 1, wherein: The thickness of the barrier layer is 0.1 mm - 0.2 mm.

5. The multi-layer composite fuel pipe according to claim 1, wherein: The thickness of the inner barrier layer is 0.1 mm - 0.2 mm.

6. The multi-layer composite fuel pipe according to claim 1, characterized in that: The thickness of the adhesive layer is 0.1 mm - 0.2 mm.

7. The multi-layer composite fuel pipe according to claim 1, characterized in that: The wall thickness of the multi-layer composite fuel pipe is not greater than 2 mm and it is formed by a co-extrusion process in one step.

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