Double-layer composite rubber pipe for new energy automobile cooling pipeline

Abstract

The invention relates to the technical field of new energy automobile rubber pipes, in particular to a double-layer composite rubber pipe for a new energy automobile cooling pipeline. The outer rubber layer comprises components in parts by weight; and the inner rubber layer comprises components in parts by weight. The two rubber layers with different hardness are integrally formed, although the reinforcing layer is removed, the performance can be guaranteed by improving the hardness, the tensile strength of the rubber material and other indexes, and meanwhile the problem that a traditional pipeline is prone to delaminating is fundamentally solved. The cost is reduced, the production efficiency is improved, and meanwhile, the quality problems of conductive short circuit, influence on in-vehicle signal transmission and the like caused by leakage of a cooling medium due to the rubber pipe delamination problem are solved. A traditional linkage production line is replaced, the process is simple, the production efficiency can be greatly improved, and fusion and size consistency of inner and outer rubber layers are better achieved. The machine head does not need to be manually adjusted back and forth, the wall thickness is uniform, new energy automobile cooling system pipeline optimization can be met, and a new energy automobile can conveniently achieve a pipeline connection mode of a quick connector.

Description

Technical Field

[0001] The invention relates to the technical field of new energy vehicle hoses, and in particular to a double-layer composite hose used for a cooling pipeline of a new energy vehicle. Background Art

[0002] As the global environmental situation becomes increasingly severe, my country is gradually moving towards new energy, and governments at all levels have gradually formulated a series of policies and regulations on energy conservation and emission reduction. As a functional product that cools key components such as batteries and electronic controls, the cooling system of new energy vehicles plays a very important role in the vehicle's endurance, cooling and thermal management systems.

[0003] At present, low-pressure cooling pipe hoses mostly adopt a composite structure of "inner rubber + fiber reinforcement layer + outer rubber". Since this structure can achieve a bursting pressure of more than 1Mpa, it has been widely used in fuel vehicles and new energy vehicles in some special scenarios. However, in actual application, since the fiber skeleton is used as a reinforcement layer in the middle of the composite structure, this structural product has disadvantages such as complex process and poor stability of bonding strength indicators. In addition, when the car is in a dynamic driving state, the more complex the structure, the more likely it is to cause delamination problems. The delamination problem of the hose will directly lead to leakage of the cooling medium or even rupture of the hose, causing a conductive short circuit, affecting the signal transmission in the car, and causing major safety problems.

[0004] Publication No. CN117106262A discloses a TPV material for automobile cooling pipes. The rubber phase in the patented material system uses a rubber system shared by EPDM rubber and butyl rubber to improve the overall resilience of TPV, thereby improving the compression permanent deformation performance, that is, better sealing. However, the operating temperature of TPV material hoses cannot exceed 70°C, while the operating temperature of low-pressure hoses in the cooling system of the new energy field is 80--45°C, so TPV materials are not fully applicable to the cooling system of new energy vehicles.

[0005] In addition, nylon tubes are often used in the prior art, but nylon tubes have problems such as becoming brittle and not corrosion-resistant after long-term use. Summary of the invention

[0006] The purpose of the present invention is to provide a double-layer composite hose for the cooling pipeline of new energy vehicles, which can reduce material costs and simplify production processes by expanding the applicable temperature range of the hose and improving its adaptability to high and low temperature pulses while preventing delamination and leakage.

[0007] To achieve the above object, the double-layer composite rubber hose for the cooling pipeline of new energy vehicles provided by the present invention is made of EPDM rubber sheets of an outer rubber layer and an inner rubber layer through double-layer composite co-extrusion into a tube embryo, and saturated steam vulcanization molding, characterized in that the outer rubber layer comprises the following components by weight: 25-30 parts of K8570c brand EPDM original rubber, 75-80 parts of 2470C brand EPDM original rubber, 5-6 parts of zinc oxide, 1-1.2 parts of stearic acid, 1-1.2 parts of antioxidant RD, 1.5-1.7 parts of polyethylene wax, 3-3. 5 parts, SL-3020 adhesive 5-6 parts, N550 carbon black 60-65 parts, N330 carbon black 10-15 parts, clay or heavy calcium carbonate 30-35 parts, YL-101 composite flame retardant 58-60 parts, paraffin oil 10-12 parts, accelerator DM: 1.0-1.2 parts, accelerator Bz: 1.0-1.2 parts, accelerator CZ: 1.5-2 parts, accelerator TMTD: 0.5-0.6 parts, accelerator TRA: 0.5-0.7 parts, accelerator DTDM: 1.0-1.2 parts, sulfur 1.3-1.5 parts;

[0008] The inner rubber layer comprises the following ingredients in parts by weight: 80-85 parts of 6470C brand EPDM rubber, 20-25 parts of butyl rubber 1751, 1.0-1.2 parts of stearic acid, 1-1.2 parts of antioxidant MBZ, 1-1.2 parts of antioxidant RD, 65-70 parts of N550 carbon black, 10-12 parts of polybutene, 7.5-8 parts of crosslinking agent DCP (40% content), 1.0-1.2 parts of auxiliary crosslinking agent TMPT (trimethylolpropane trimethacrylate), and 0.5-0.7 parts of auxiliary crosslinking agent TAlC.

[0009] Furthermore, the outer rubber layer includes the following ingredients in parts by weight: 25 parts of K8570c brand EPDM rubber, 75 parts of 2470C EPDM rubber, 5 parts of zinc oxide, 1 part of stearic acid, 1 part of antioxidant RD, 1.5 parts of polyethylene wax, 3 parts of BN-1 tackifying resin, 5 parts of SL-3020 adhesive, 60 parts of N550 carbon black, 10 parts of N330 carbon black, 30 parts of clay or heavy calcium carbonate, 58 parts of YL-101 composite flame retardant, 10 parts of paraffin oil, 1.0 part of accelerator DM, 1.0 part of accelerator Bz, 1.5 parts of accelerator CZ, The accelerator TMTD: 0.5 parts, the accelerator TRA: 0.5 parts, the accelerator DTDM: 1.0 parts, and the sulfur: 1.3 parts; the inner rubber layer comprises the following components in parts by weight: 80 parts of 6470C brand EPDM rubber, 20 parts of butyl rubber 1751, 1.0 parts of stearic acid, 1 part of antioxidant MBZ, 1 part of antioxidant RD, 65 parts of N550 carbon black, 10 parts of polybutene, 7.5 parts of crosslinking agent DCP (40% content), 1.0 parts of auxiliary crosslinking agent TMPT (trimethylolpropane trimethacrylate), and 0.5 parts of auxiliary crosslinking agent TAlC.

[0010] Furthermore, the outer rubber layer is made of a rubber compound with a Shore A hardness of 80±5HA.

[0011] Furthermore, the inner rubber layer is made of a rubber compound with a Shore A hardness of 70±5HA.

[0012] Furthermore, the ratio of the outer rubber layer to the inner rubber layer in terms of thickness unit is 2:1.

[0013] Furthermore, the wall thickness of the double-layer composite hose is 3-6 mm.

[0014] The present invention also provides a method for preparing a double-layer composite hose for a cooling pipeline of a new energy vehicle, which is characterized by comprising the following steps:

[0015] S1 weighs the raw materials: use the automatic batching system to batch the ingredients according to the rubber recipe;

[0016] S2 Mixing: Use a fully automatic rubber mixing center to prepare EPDM pipe rubber and keep it at constant temperature and humidity for 8-48 hours according to process requirements;

[0017] S3 double-layer composite co-extrusion: two rubber extruders are used to produce tube blanks with two heads in one extrusion molding process, and they are automatically cut into required lengths for standby use;

[0018] S4 vulcanization: Use a special molding mold surface to coat an environmentally friendly water-soluble release agent, take the above-mentioned tube embryo for embryo swallowing molding, and put the semi-finished product into the vulcanization car for vulcanization; use a gas vulcanization tank for high-temperature steam vulcanization, the vulcanization conditions are a vulcanization pressure of 0.7Mpa and a vulcanization time of 60min.

[0019] S5 Cleaning and Packaging: After demoulding, use a special cleaning machine to clean according to the process requirements, use special tooling to cut the tube head, and after completing the logo engraving as required, use special dust caps to seal both ends to obtain the finished hose.

[0020] Furthermore, the constant temperature and humidity conditions are temperature 20±3°C & humidity 50±10%RH.

[0021] The double-layer composite hose for the cooling pipeline of new energy vehicles provided by the present invention has the following positive effects:

[0022] 1. In the prior art, the pipeline system containing a reinforcement layer can withstand a greater bursting pressure, which is mainly for fuel vehicles, especially heavy trucks. However, the pressure of the hose of the cooling system of new energy vehicles is relatively small, generally 0.3-0.4 MPa. The method of the present invention creatively uses two rubber layers with different hardness to form an integral part. Although the reinforcement layer is removed, the performance can be guaranteed by improving the hardness and tensile strength of the rubber material, and at the same time, the problem of easy delamination of traditional pipes is fundamentally solved.

[0023] 2. The method of the present invention adopts a two-layer pure glue process, which reduces costs and improves production efficiency. It also solves the quality problems such as conductive short circuit caused by leakage of cooling medium due to delamination of the hose, affecting the transmission signal in the car.

[0024] 3. The inner rubber layer of the method of the present invention adopts a rubber material with a Shore A hardness of 70±5HA to improve the sealing performance, and the outer rubber layer adopts a rubber material with a Shore A hardness of 80±5HA to improve the tensile strength and surface wear resistance of the hose.

[0025] 4. The production equipment is changed from the original linkage production line of two rubber extruders and a knitting machine or winding machine in the middle to a one-time extrusion molding process using two rubber extruders, thereby obtaining a low-pressure rubber hose with a composite structure of two layers with different hardnesses. The method of the present invention replaces the traditional linkage production line, has a simple process, can greatly improve production efficiency, and better achieves the fusion of the inner and outer layers of rubber and the dimensional consistency.

[0026] 5. The composite rubber hose of the invention method can achieve a wall thickness of 3-6mm, and since there is no need to manually adjust the machine head, the wall thickness is uniform, which can meet the optimization of the pipeline of the cooling system of new energy vehicles and facilitate the new energy vehicles to realize the pipeline connection method of quick-connect connectors. DETAILED DESCRIPTION

[0027] The present invention is further described below by way of examples.

[0028] Example:

[0029] The double-layer composite hose for the cooling pipeline of new energy vehicles provided by the present invention is made of EPDM rubber sheets of an outer rubber layer and an inner rubber layer through double-layer composite co-extrusion to form a tube embryo, and is formed by saturated steam vulcanization, wherein the ratio of the outer rubber layer to the inner rubber layer in terms of unit thickness is 2:1.

[0030] The outer rubber layer includes the following ingredients in parts by weight: 25 parts of K8570c brand ethylene propylene diene monomer rubber (referred to as EPDM rubber), 75 parts of 2470C ethylene propylene diene monomer rubber, 5 parts of zinc oxide, 1 part of stearic acid, 1 part of antioxidant RD, 1.5 parts of polyethylene wax, 3 parts of BN-1 tackifying resin, 5 parts of SL-3020 adhesive, 60 parts of N550 carbon black, 10 parts of N330 carbon black, 30 parts of clay or heavy calcium carbonate, 58 parts of YL-101 composite flame retardant, 10 parts of paraffin oil, 1.0 part of accelerator DM, 1.0 part of accelerator Bz, 1.5 parts of accelerator CZ, 0.5 part of accelerator TMTD, 0.5 part of accelerator TRA, 1.0 part of accelerator DTDM, and 1.3 parts of sulfur.

[0031] The inner rubber layer comprises the following ingredients in parts by weight: 80 parts of 6470C brand EPDM rubber, 20 parts of butyl rubber 1751, 1.0 parts of stearic acid, 1 part of antioxidant MBZ, 1 part of antioxidant RD, 65 parts of N550 carbon black, 10 parts of polybutene, 7.5 parts of crosslinking agent DCP (40% content), 1.0 part of auxiliary crosslinking agent TMPT (trimethylolpropane trimethacrylate), and 0.5 part of auxiliary crosslinking agent TAlC.

[0032] The inner rubber layer is made of EPDM rubber with a Shore A hardness of 70±5HA to improve the sealing performance, and the outer rubber layer is made of Shore A hardness of 80±5HA to improve the strength and surface wear resistance of the hose. The wall thickness of the double-layer composite hose is 3-6mm.

[0033] The embodiment of the present invention also provides a method for preparing a double-layer composite hose for a cooling pipeline of a new energy vehicle, which is characterized by comprising the following steps:

[0034] S1 weighs the raw materials and uses the automatic batching system to batch the outer rubber layer and the inner rubber layer according to the rubber recipe. The weighing accuracy is controlled at ±0.1g to ensure the stability of its physical and mechanical properties;

[0035] S2 Mixing, use the fully automatic rubber mixing center to prepare EPDM pipe rubber, and park it under constant temperature and humidity conditions of 20±3℃ and 50±10%RH for 8-48 hours according to the process requirements;

[0036] S3 double-layer composite co-extrusion, using two rubber extruders with two heads to produce tube blanks in one extrusion molding process, and automatically cut them into required lengths for standby use;

[0037] S4 vulcanization, use a special molding mold surface coated with an environmentally friendly water-soluble release agent, then use the parked tube embryo to swallow the embryo molding, put the semi-finished product into the vulcanization car for vulcanization; then use the gas vulcanization tank for high-temperature steam vulcanization, the vulcanization conditions are vulcanization pressure of 0.7Mpa, and vulcanization time of 60min.

[0038] S5 is cleaned, packaged and demoulded, and then cleaned using a special cleaning machine according to the process requirements. Special tooling is used to cut the tube heads. After the logo is engraved as required, special dust caps are used to seal both ends.

[0039] Table 1 Comparison of performance indicators of the embodiment and conventional pipeline products with reinforcement layer

[0040]

[0041]

[0042] The examples in Table 1 are performance index comparisons of the hose products made by the above-mentioned inventive method and the traditional pipe products with a reinforcement layer. The performance tests of the examples and the comparative examples are carried out in accordance with national standards.

[0043] By comparing the data in the table, it can be seen that compared with the traditional pipeline products with reinforced layers, the hose product obtained in this embodiment has excellent comprehensive performance such as hardness, low temperature resistance, sealing and low temperature pressure change. Especially in the comparison of high and low temperature pulse experiments, the method of the present invention can achieve the sealing performance of the high temperature pulse experiment while better realizing the sealing performance of the low temperature pulse experiment. The pipeline product with a reinforced layer leaks at -45℃*0.07~0.2Mpa*10Hz*24h, while the product of the present invention still has no leakage at -45℃*0.07~0.2Mpa*10Hz*72h, which fully reflects the advantages of this patent under low temperature conditions.

[0044] It should be noted that the specific embodiments of the present invention have been described in detail. For those skilled in the art, various obvious changes to the present invention without departing from the spirit and scope of the present invention are within the protection scope of the present invention.

Claims

1. A double-layer composite hose for the cooling pipeline of new energy vehicles, which is made of EPDM rubber sheets of an outer rubber layer and an inner rubber layer through double-layer composite co-extrusion to form a tube embryo, and saturated steam vulcanization molding, characterized in that: The outer rubber layer comprises the following ingredients in parts by weight: 25-30 parts of K8570c brand EPDM rubber, 75-80 parts of 2470C brand EPDM rubber, 5-6 parts of zinc oxide, 1-1.2 parts of stearic acid, 1-1.2 parts of antioxidant RD, 1.5-1.7 parts of polyethylene wax, 3-3.5 parts of BN-1 tackifying resin, 5-6 parts of SL-3020 adhesive, 60-65 parts of N550 carbon black, 10-15 parts of N330 carbon black, 30-35 parts of clay or heavy calcium carbonate, 58-60 parts of YL-101 composite flame retardant, 10-12 parts of paraffin oil, 1.0-1.2 parts of accelerator DM, 1.0-1.2 parts of accelerator Bz, 1.0-1.2 parts of accelerator CZ. .5-2 parts, accelerator TMTD: 0.5-0.6 parts, accelerator TRA: 0.5-0.7 parts, accelerator DTDM: 1.0-1.2 parts, sulfur 1.3-1.5 parts; the inner rubber layer includes the following ingredients in parts by weight: 6470C brand EPDM original rubber 80-85 parts, butyl rubber 1751: 20-25 parts, stearic acid 1.0-1.2 parts, antioxidant MBZ: 1-1.2 parts, antioxidant RD: 1-1.2 parts, N550 carbon black 65-70 parts, polybutene 10-12 parts, crosslinking agent DCP (40% content): 7.5-8 parts, co-crosslinking agent TMPT: 1.0-1.2 parts, co-crosslinking agent TAlC: 0.5-0.7 parts.

2. The double-layer composite hose for the cooling pipeline of new energy vehicles according to claim 1 is also characterized in that: The outer rubber layer includes the following ingredients in parts by weight: 25 parts of K8570c brand EPDM rubber, 75 parts of 2470C EPDM rubber, 5 parts of zinc oxide, 1 part of stearic acid, 1 part of antioxidant RD, 1.5 parts of polyethylene wax, 3 parts of BN-1 tackifying resin, 5 parts of SL-3020 adhesive, 60 parts of N550 carbon black, 10 parts of N330 carbon black, 30 parts of clay or heavy calcium carbonate, 58 parts of YL-101 composite flame retardant, 10 parts of paraffin oil, 1.0 parts of accelerator DM, 1.0 parts of accelerator Bz, Accelerator CZ: 1.5 parts, accelerator TMTD: 0.5 parts, accelerator TRA: 0.5 parts, accelerator DTDM: 1.0 parts, sulfur 1.3 parts; the inner rubber layer includes the following components in parts by weight: 80 parts of 6470C brand EPDM rubber, 20 parts of butyl rubber 1751, 1.0 parts of stearic acid, 1 part of antioxidant MBZ, 1 part of antioxidant RD, 65 parts of N550 carbon black, 10 parts of polybutene, 7.5 parts of crosslinking agent DCP (40% content), 1.0 parts of auxiliary crosslinking agent TMPT (trimethylolpropane trimethacrylate), and 0.5 parts of auxiliary crosslinking agent TAlC.

3. The double-layer composite hose for the cooling pipeline of new energy vehicles according to claim 1 is also characterized in that: The outer rubber layer is made of rubber compound with a Shore A hardness of 80±5HA.

4. The double-layer composite hose for the cooling pipeline of new energy vehicles according to claim 1 is also characterized in that: The inner rubber layer is made of rubber compound with a Shore A hardness of 70±5HA.

5. The double-layer composite hose for the cooling pipeline of new energy vehicles according to claim 2 is also characterized in that: The ratio of the outer rubber layer to the inner rubber layer is 2:1 in terms of thickness unit.

6. The double-layer composite hose for the cooling pipeline of new energy vehicles according to claim 1 is also characterized in that: The wall thickness of the double-layer composite hose is 3-6 mm.

7. The double-layer composite hose for the cooling pipeline of new energy vehicles according to claim 1 is also characterized in that: The preparation method is as follows: S1 weighs the raw materials: use the automatic batching system to batch the ingredients according to the rubber recipe; S2 Mixing: Use a fully automatic rubber mixing center to prepare EPDM pipe rubber and keep it at constant temperature and humidity for 8-48 hours according to process requirements; S3 double-layer composite co-extrusion: two rubber extruders are used to produce tube blanks with two heads in one extrusion molding process, and they are automatically cut into required lengths for standby use; S4 vulcanization: Use a special molding mold surface to coat an environmentally friendly water-soluble release agent, take the above-mentioned tube embryo for embryo swallowing molding, and put the semi-finished product into the vulcanization car for vulcanization; use a gas vulcanization tank for high-temperature steam vulcanization, the vulcanization conditions are a vulcanization pressure of 0.7Mpa and a vulcanization time of 60min. 8.S5 Cleaning and Packaging: After demoulding, use a special cleaning machine to clean according to the process requirements, use special tooling to cut the tube head, and after completing the logo engraving as required, use special dust caps to seal both ends to obtain the finished hose.

9. The double-layer composite hose for the cooling pipeline of new energy vehicles according to claim 7 is also characterized in that: The constant temperature and humidity conditions are 20±3°C and 50±10%RH.

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