Automobile water pipe multilayer thermal insulation structure and preparation method thereof

Abstract

The present application relates to a kind of automobile water pipe multilayer insulation structure and preparation method thereof, structure includes: automobile water pipe body, and the multilayer insulation body integrally formed with automobile water pipe body;Multilayer insulation body includes sequentially from inside to outside, adhering layer, insulation core layer and protective layer;Method includes: step one: by extruder forming automobile water pipe body;Step two: in the same production line or series production line, by multiple co-extrusion machine sequentially in the water pipe body outer wall co-extrusion covering adhering layer, insulation core layer and protective layer, form integrally formed multilayer insulation body;Step three: to the composite pipe material after forming is cooled and shaped;The present application aims at solving the existing split type insulation sleeve easy to crack, poor insulation effect and inconvenient maintenance and other problems, fundamentally avoids interlayer peeling and bending crack, significantly improves insulation efficiency, structural integrity and service life, especially suitable for compact space, pipeline complex automobile cooling system and air conditioning system.

Description

Technical Field

[0001] This invention relates to the field of automotive parts manufacturing technology, and in particular to a multi-layer insulation structure for automotive water pipes and its preparation method. Background Technology

[0002] Automotive engine coolant hoses and air conditioning pipes are key components of a vehicle's thermal management system. They operate in harsh environments, enduring long-term high and low temperature cycles, vibration, oil contamination, and mechanical stress. To prevent excessive heat loss or external heat intrusion and to ensure system efficiency, these pipes are typically insulated.

[0003] Existing technologies mostly use independent foam rubber sleeves, which are manually fitted onto the outside of the water pipes after installation. This method has inherent drawbacks: First, there is an assembly gap between the sleeve and the water pipe, forming an air thermal bridge and severely weakening the insulation effect; second, the independent sleeve has poor material uniformity and interfacial bonding, making it prone to cracking due to stress concentration at pipe bends; third, its wear resistance and oil resistance are insufficient, resulting in a short lifespan in the engine compartment; finally, the split structure is cumbersome to install and requires complete replacement during maintenance, leading to high maintenance costs.

[0004] Therefore, there is an urgent need in this field for an integrated insulation solution that can be firmly bonded to the water pipe body and has excellent thermal insulation performance, bending toughness and long-term durability. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a multi-layer thermal insulation structure for automotive water pipes and its preparation method.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] A multi-layer insulation structure for automotive water pipes includes an automotive water pipe body and a multi-layer insulation body integrally formed with the automotive water pipe body.

[0008] The multi-layer insulation body comprises, from the inside out, an adhesive layer, an insulation core layer, and a protective layer.

[0009] Preferably, the bonding layer material is elastic silicone rubber.

[0010] Preferably, the insulation core material is flame-retardant microporous polyurethane foam or environmentally friendly centrifugal glass wool.

[0011] Preferably, the protective layer material is wear-resistant polyvinyl chloride or ethylene propylene diene monomer (EPDM) rubber.

[0012] Preferably, at the curved section of the car water pipe body, the multi-layer insulation body has an integrally formed annular pleated structure to accommodate bending deformation.

[0013] A method for preparing an automotive water pipe insulation structure includes the following steps:

[0014] Step 1: Form the car water pipe body using an extruder;

[0015] Step 2: On the same or tandem production line, multiple co-extrusion machines are used to co-extrude and coat the outer wall of the water pipe body with an adhesive layer, an insulation core layer, and a protective layer in sequence, forming an integrally molded multi-layer insulation body;

[0016] Step 3: Cool and set the formed composite pipe.

[0017] Preferably, the bonding layer material forms an interface bond with the car water pipe body material in a molten state, and is then wrapped by its own elasticity after cooling.

[0018] Preferably, during the molding process of the insulation core layer, when the insulation core layer material is flame-retardant microporous polyurethane foam, foaming and co-extrusion are carried out simultaneously, while the foaming ratio and temperature are controlled.

[0019] Preferably, in step three, an annular pleated structure is formed by hot pressing with a mold at the curved section of the car water pipe body.

[0020] Beneficial effects:

[0021] 1. Integration and reliability: The multi-layer structure is formed in one step through co-extrusion process, with strong interlayer bonding, no risk of falling off, and the structural life is synchronized with the water pipe body.

[0022] 2. Superior thermal insulation: The seamless bonding layer greatly reduces contact thermal resistance, and combined with the low thermal conductivity insulation core layer, the overall thermal insulation performance is significantly better than that of the split kit.

[0023] 3. Exceptional flexibility: The elastic design of the overall material and the introduction of ring-shaped pleats allow the structure to bend freely with the water pipes without breaking, adapting to any complex engine compartment layout.

[0024] 4. Permanent durability: The outer protective layer provides a robust barrier for the fragile internal insulation material, enabling the product to withstand long-term vibration, abrasion, and chemical corrosion. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0026] Figure 2 This is a schematic diagram of the overall structure of the present invention.

[0027] In the diagram: 1. Car water pipe body; 2. Adhesive layer; 3. Insulation core layer; 4. Protective layer. Detailed Implementation

[0028] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0029] like Figure 1-2 As shown: The present invention provides a multi-layer insulation structure for automotive water pipes, including an automotive water pipe body 1 and a multi-layer insulation body integrally formed with the automotive water pipe body 1.

[0030] The multi-layer insulation body consists of an adhesive layer 2, an insulation core layer 3, and a protective layer 4, from the inside out.

[0031] The bonding layer 2 is made of elastic silicone rubber. This layer is made of elastic silicone rubber with a preferred thickness of 0.5-1mm. It is directly fused to the outer wall of the car water pipe body 1, and its high elasticity and adhesion achieve a seamless bond at the molecular level, completely eliminating the interfacial air layer.

[0032] The insulation core layer 3 is made of flame-retardant microporous polyurethane foam or environmentally friendly centrifugal glass wool. This layer is made of flame-retardant microporous polyurethane foam or environmentally friendly centrifugal glass wool, with a thickness of preferably 3~5mm and a thermal conductivity preferably not higher than 0.03W / (m·℃). As the main insulation layer, its closed-cell structure can effectively suppress convection and radiation heat transfer.

[0033] The protective layer 4 is made of abrasion-resistant polyvinyl chloride or EPDM rubber. This layer is made of abrasion-resistant polyvinyl chloride or EPDM rubber, with a preferred thickness of 1~1.5mm. It provides mechanical protection for the overall structure and has excellent scratch resistance, oil resistance and UV resistance.

[0034] At the bend in the main body 1 of the automotive water pipe, an annular pleated structure is integrally formed on the multi-layer insulation to accommodate bending deformation. This annular pleated structure can freely expand and contract during bending, thereby releasing stress, preventing fatigue cracks in the insulation layer, and thus adapting to the bending deformation of the pipe.

[0035] This invention also provides a method for preparing an automotive water pipe insulation structure, comprising the following steps:

[0036] Step 1: Form the car water pipe body 1 using an extruder;

[0037] Step 2: On the same production line or in series production lines, multiple co-extrusion machines are used to co-extrude and coat the outer wall of the water pipe body with the bonding layer 2, the insulation core layer 3 and the protective layer 4 in sequence to form an integral multi-layer insulation body;

[0038] Step 3: Cool and set the formed composite pipe.

[0039] The bonding layer 2 material forms an interface bond with the car water pipe body 1 material in the molten state, and is wrapped by its own elasticity after cooling.

[0040] During the molding process of the insulation core layer 3, when the material of the insulation core layer 3 is flame-retardant microporous polyurethane foam, foaming and co-extrusion are carried out simultaneously, while the foaming ratio and temperature are controlled. This step can ensure that the foam cells are uniform and fine.

[0041] In step three, an annular pleated structure is formed by hot pressing with a mold at the curved section of the car water pipe body 1.

[0042] Taking the one-piece molded insulated water pipe used in the cooling circuit of an automotive turbocharger as an example, the specific manufacturing process is as follows:

[0043] Base pipe manufacturing: First, the automotive water pipe body 1, made of EPDM rubber (ethylene propylene diene monomer rubber), is formed by extrusion.

[0044] Co-extrusion Molding: Subsequently, on the same or tandem production line, multiple co-extrusion machines sequentially form each functional layer: Adhesive Layer 2: A 0.8mm thick elastic silicone rubber is directly co-extruded and coated onto the outer wall of the automotive water pipe body 1. This layer material forms a strong interfacial bond with the EPDM base pipe in the molten state, and after cooling, it tightly wraps the pipe due to its own elasticity. Insulation Core Layer 3: Immediately, a foamed prepolymer (such as flame-retardant microporous polyurethane foam) is co-extruded onto the outer wall of the adhesive layer 2, forming a 4mm thick foam insulation layer with a thermal conductivity of 0.028W / (m·℃). The foaming process is controlled synchronously with the co-extrusion process to ensure uniform and fine cell structure. Protective Layer 4: Finally, a 1.2mm thick weather-resistant PVC is co-extruded and coated onto the outer wall of the insulation core layer 3, forming a smooth and tough outer protective shell.

[0045] Post-processing and bending: After the extruded composite pipe is cooled and shaped, it is hot-pressed in the part that needs to be bent to give the pipe the preset bending ability.

[0046] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-layer insulation structure for automotive water pipes, characterized in that, It includes the main body of the car water pipe and a multi-layer insulation body integrally formed with the main body of the car water pipe; The multi-layer insulation body comprises, from the inside out, an adhesive layer, an insulation core layer, and a protective layer.

2. The multi-layer insulation structure for automotive water pipes as described in claim 1, characterized in that, The bonding layer material is elastic silicone rubber.

3. The multi-layer insulation structure for automotive water pipes as described in claim 2, characterized in that, The insulation core material is flame-retardant microporous polyurethane foam or environmentally friendly centrifugal glass wool.

4. The multi-layer insulation structure for automotive water pipes as described in claim 3, characterized in that, The protective layer material is wear-resistant polyvinyl chloride or EPDM rubber.

5. The multi-layer insulation structure for automotive water pipes as described in claim 4, characterized in that, At the bend of the car water pipe body, the multi-layer insulation body has an integrally formed annular pleated structure to accommodate bending deformation.

6. A method for preparing an automotive water pipe insulation structure as described in any one of claims 1 to 5, characterized in that, Includes the following steps: Step 1: Form the car water pipe body using an extruder; Step 2: On the same or tandem production line, multiple co-extrusion machines are used to co-extrude and coat the outer wall of the water pipe body with an adhesive layer, an insulation core layer, and a protective layer in sequence, forming an integrally molded multi-layer insulation body; Step 3: Cool and set the formed composite pipe.

7. The method for preparing the automotive water pipe insulation structure as described in claim 6, characterized in that, The bonding layer material forms an interface bond with the car water pipe body material in the molten state, and is wrapped by its own elasticity after cooling.

8. The method for preparing the automotive water pipe insulation structure as described in claim 7, characterized in that, During the molding process of the insulation core layer, when the insulation core layer material is flame-retardant microporous polyurethane foam, foaming and co-extrusion are carried out simultaneously, while the foaming ratio and temperature are controlled.

9. The method for preparing the automotive water pipe insulation structure as described in claim 8, characterized in that, In step three, an annular pleated structure is formed by hot pressing with a mold at the curved section of the car water pipe body.

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