A High-Temperature-Resistant Cable for Electric Vehicle Chargers and Its Preparation Method

Abstract

The present invention provides a high-temperature resistant cable for an electric vehicle charging pile and a preparation method thereof, relating to the technical field of cable processing. The high-temperature resistant cable for an electric vehicle charging pile includes an outer sheath and a central core disposed inside the outer sheath. A layer of inner sheath is disposed inside the outer sheath. The central core is disposed at the center inside the inner sheath. A plurality of auxiliary cores are disposed between the central core and the inner sheath. An insulating layer is wrapped around the outer portions of the auxiliary cores and the central core. A filling layer is filled between the outer portion of the insulating layer and the inner sheath. The inner sheath, the outer sheath, and the insulating layer are all made by extrusion of high-temperature resistant materials such as high-density polyethylene, polyamide resin, silicone rubber, polyimide powder, nano-aluminum oxide, and flame retardant. The present invention overcomes the deficiencies of the prior art, ensures the safety and stability of the cable during use, guarantees the overall high-temperature resistant performance of the cable through the high-temperature resistant material, and ensures the safety of new energy vehicles during fast charging.

Description

Technical Field

[0001] The present invention relates to the technical field of cable processing, and particularly relates to a high-temperature resistant cable for an electric vehicle charging pile and a preparation method thereof. Background Art

[0002] The exhaust emissions of fuel vehicles have become the primary cause of urban pollution. The emission of a large amount of pollutants has led to frequent occurrences of smoggy weather in major cities in recent years. In order to reduce vehicle exhaust pollution emissions, promoting new energy electric vehicles is an important solution at this stage. To facilitate the use of new energy electric vehicles, charging piles have now been installed in various parking lots to ensure the use of new energy vehicles.

[0003] There are two usage modes for the cables used in the charging system of new energy electric vehicles: one is to be placed on the electric vehicle and used in different environments following the vehicle; the other is to be installed on the charging pile and mainly used in environments such as parking lots, garages, and roadside. And the charging speed of new energy vehicles is an important factor restricting the development of electric vehicles. High-power charging is the mainstream trend of future development. Fast charging can significantly shorten the charging time, but a large current will inevitably bring heat generation problems. The accumulation of a large amount of heat will not only accelerate the aging of the cable insulation or sheath but may even damage the cable, posing a threat to the life and property of users. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a high-temperature resistant cable for an electric vehicle charging pile and a preparation method thereof. By providing multiple protections for the inner core of the cable, the safety and stability of the cable during use are ensured. At the same time, through a special high-temperature resistant material, the overall high-temperature resistant performance of the cable is guaranteed, ensuring the safety of new energy vehicles during fast charging.

[0005] To achieve the above objectives, the technical solution of the present invention is realized through the following technical means:

[0006] A high-temperature resistant cable for an electric vehicle charging pile, comprising an outer sheath and a central core disposed inside the outer sheath. A layer of inner sheath is disposed inside the outer sheath. The central core is disposed at the center inside the inner sheath. A plurality of auxiliary cores are disposed between the central core and the inner sheath. Insulation layers are wrapped around the auxiliary cores and the central core, and a filling layer is filled between the outer layer of the insulation layer and the inner sheath.

[0007] Preferably, a shielding layer is disposed between the outer sheath and the inner sheath.

[0008] Preferably, a filling core is disposed between two auxiliary cores.

[0009] A preparation method of a high-temperature resistant cable for an electric vehicle charging pile, comprising the following steps:

[0010] ① Preparation of high-temperature resistant material: After heating high-density polyethylene and nano-aluminum oxide to 150 °C for mixing and modification, polyimide powder, polyamide resin, flame retardant, compatibilizer, and silicone rubber are added and mixed and stirred at 180 °C for 2 h, followed by irradiation modification. Then, accelerator, plasticizer, and silane coupling agent are added, and the mixture is kneaded and extruded to obtain the high-temperature resistant material for standby;

[0011] ② Conductor treatment: Annealed copper wire is selected as the conductor. Multiple conductors are stranded and then wrapped with non-woven fabric. After that, the stranded conductors are extruded with the above-mentioned high-temperature resistant material on the outside to obtain the core for standby;

[0012] ③ Filler treatment: Polypropylene filling rope is selected as the filling material. Multiple polypropylene filling ropes are stranded and the outside is wrapped with non-woven fabric to form a large filler for standby;

[0013] ④ Cable stranding: Multiple above-mentioned cores, large fillers, and ordinary polypropylene filling ropes are arranged and stranded, and then extruded with the above-mentioned high-temperature resistant material to obtain the preformed cable for standby;

[0014] ⑤ Cable forming: The outside of the above-mentioned preformed cable is braided into a shielding mesh layer with annealed copper wire, and then extruded with the above-mentioned high-temperature resistant material on the outside of the shielding mesh layer to obtain the high-temperature resistant cable.

[0015] Preferably, the weights of each substance in step ① are: 40 - 50 parts of high-density polyethylene, 10 - 12 parts of polyamide resin, 8 - 10 parts of silicone rubber, 4 - 6 parts of polyimide powder, 1 - 2 parts of nano-aluminum oxide, 1.5 - 2 parts of flame retardant, 1 - 2 parts of compatibilizer, 0.8 - 1.2 parts of accelerator, 1 - 3 parts of plasticizer, and 2 - 3 parts of silane coupling agent.

[0016] Preferably, in step ①, 60Co source is used for irradiation, and the irradiation dose is 200 kGy.

[0017] Preferably, the kneading method in step ① is to knead at 180 °C for 40 min first, then knead at 190 °C for 30 min, and then knead at 150 °C for 2 h.

[0018] Preferably, the flame retardant is one or a combination of ammonium polyphosphate, antimony oxide, and zinc borate.

[0019] Preferably, the extrusion thickness of the high-temperature resistant material in step ② is 0.4 mm ± 0.1 mm, the extrusion thickness of the high-temperature resistant material in step ④ is 0.6 mm ± 0.1 mm, and the extrusion thickness of the high-temperature resistant material in step ⑤ is 4.5 ± 0.3 mm.

[0020] The present invention provides a high-temperature resistant cable for electric vehicle chargers and its preparation method. Compared with the prior art, the advantages are as follows:

[0021] (1) The present invention adopts a mode in which multiple auxiliary cores surround the central core, and at the same time, an auxiliary filling layer and a filling core are arranged during this process, effectively ensuring the stability of the cable line, reducing the power transmission pressure of a single core, and at the same time effectively separating each group of cores to prevent the temperature at the joint from being too high due to excessive closeness of multiple groups of cores, resulting in uneven heat aging inside the cable and reducing the occurrence of potential safety hazards.

[0022] (2) The present invention prepares a high-temperature resistant material as the protective material of the cable. Among them, high-density polyethylene is mixed with nano-aluminum oxide for preliminary modification, and then polyimide powder, polyamide resin, flame retardant, silicone rubber, etc. are continuously mixed for radiation modification, effectively improving the heat resistance of the material and ensuring the safety of the charging cable for new energy vehicles during fast charging. Description of the Drawings

[0023] Figure 1 It is a schematic cross-sectional view of the cable of the present invention.

[0024] 1. Outer sheath; 2. Shielding layer; 3. Inner sheath; 4. Central core; 5. First auxiliary core; 6. Filling core; 7. Insulation layer; 8. Filling layer. Detailed Embodiments

[0025] To make the objectives, 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 embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0026] Embodiment 1:

[0027] Preparation of the high-temperature resistant material:

[0028] 1. Preparation of materials: Prepare 40 parts of high-density polyethylene, 10 parts of polyamide resin, 8 parts of silicone rubber, 4 parts of polyimide powder, 1 part of nano-aluminum oxide, 1.5 parts of antimony oxide, 1 part of compatibilizer MAH, 0.8 part of accelerator EP-184, 1 part of dimethyl phthalate, and 2 parts of silane coupling agent A151 according to weight parts.

[0029] 2. Preliminary modification: Mix high-density polyethylene and nano-aluminum oxide and heat them to 150 °C, mix and modify them at a stirring speed of 1200 r / min for 20 min, then add polyimide powder, mix polyamide resin, antimony oxide, compatibilizer MAH, and silicone rubber, heat them to 180 °C, and stir them with a mixer for 2 h. 60Irradiation modification was carried out with a Co source and an irradiation dose of 200 kGy. Then, accelerator EP-184, dimethyl phthalate, and silane coupling agent A151 were added. The mixture was kneaded in a kneader at 180 °C for 40 min, then at 190 °C for 30 min, and then at 150 °C for 2 h. Finally, it was extruded to obtain the high-temperature resistant material.

[0030] Example 2:

[0031] Preparation of high-temperature resistant material:

[0032] 1. Preparation of materials: Prepare 50 parts by weight of high-density polyethylene, 12 parts of polyamide resin, 10 parts of silicone rubber, 6 parts of polyimide powder, 2 parts of nano-aluminum oxide, 2 parts of antimony oxide, 2 parts of compatibilizer MAH, 1.2 parts of accelerator EP-184, 3 parts of dimethyl phthalate, and 3 parts of silane coupling agent A151.

[0033] 2. Preliminary modification: Heat the mixture of high-density polyethylene and nano-aluminum oxide to 150 °C and mix and modify it at a stirring speed of 1200 r / min for 20 min. Then add polyimide powder and mix polyamide resin, antimony oxide, compatibilizer MAH, and silicone rubber and heat to 180 °C. Stir with a kneader for 2 h, and use 60 Irradiation modification was carried out with a Co source and an irradiation dose of 200 kGy. Then, accelerator EP-184, dimethyl phthalate, and silane coupling agent A151 were added. The mixture was kneaded in a kneader at 180 °C for 40 min, then at 190 °C for 30 min, and then at 150 °C for 2 h. Finally, it was extruded to obtain the high-temperature resistant material.

[0034] Example 3:

[0035] Preparation of high-temperature resistant material:

[0036] 1. Preparation of materials: Prepare 45 parts by weight of high-density polyethylene, 11 parts of polyamide resin, 9 parts of silicone rubber, 5 parts of polyimide powder, 1.5 parts of nano-aluminum oxide, 1.8 parts of antimony oxide, 1.5 parts of compatibilizer MAH, 1 part of accelerator EP-184, 2 parts of dimethyl phthalate, and 2.5 parts of silane coupling agent A151.

[0037] 2. Preliminary modification: Heat the mixture of high-density polyethylene and nano-aluminum oxide to 150 °C and mix and modify it at a stirring speed of 1200 r / min for 20 min. Then add polyimide powder and mix polyamide resin, antimony oxide, compatibilizer MAH, and silicone rubber and heat to 180 °C. Stir with a kneader for 2 h, and use 60Irradiation modification was carried out with a Co source and an irradiation dose of 200 kGy. Then, accelerator EP-184, dimethyl phthalate, and silane coupling agent A151 were added. The mixture was kneaded in a kneader at 180 °C for 40 min, then at 190 °C for 30 min, and then at 150 °C for 2 h. Finally, it was extruded to obtain the high-temperature resistant material.

[0038] Example 4:

[0039] Preparation of high-temperature resistant cable for electric vehicle charging piles:

[0040] 1. Annealed copper wires were used as conductors. Multiple conductors were stranded and then wrapped with non-woven fabric. Then, the stranded conductors were extruded with the high-temperature resistant material obtained in Example 3 above to form an insulating layer 7. The thickness of the insulating layer 7 was 0.4 mm ± 0.1 mm. The number of conductors in each group was set according to actual needs. In this example, the cross-sectional area of the core material after final extrusion was 70 mm 2 for the central core 4, and the cross-sectional area was 40 mm 2 for the auxiliary core 5;

[0041] 2. Polypropylene filling ropes were selected as the filling material. Multiple polypropylene filling ropes were stranded and wrapped with non-woven fabric on the outside to form a large filling material as the filling core 6 for standby;

[0042] 3. Multiple auxiliary cores 5 were arranged around the central core 4, and a filling core 6 was placed between every two auxiliary cores 5. Then, the voids were filled with polypropylene filling ropes to form a filling layer 8. Then, the outside was extruded with the high-temperature resistant material obtained in Example 3 to form an inner sheath 3. The thickness of the inner sheath 3 was 0.6 mm ± 0.1 mm. An annealing copper wire was used to braid a mesh layer structure on the outside of the inner sheath 3 to form a shielding layer 2. Then, a layer of the high-temperature resistant material obtained in Example 3 was extruded on the outside of the shielding layer 2 as the outer sheath 1. The thickness of the outer sheath 1 was 4.5 ± 0.3 mm, and a high-temperature resistant cable for electric vehicle charging piles was obtained.

[0043] Comparative Example 1:

[0044] Preparation of cable material:

[0045] 1. Preparation of materials: 45 parts of high-density polyethylene, 11 parts of polyamide resin, 9 parts of silicone rubber, 5 parts of polyimide powder, 1.8 parts of antimony oxide, 1.5 parts of compatibilizer MAH, 1 part of accelerator EP-184, 2 parts of dimethyl phthalate, and 2.5 parts of silane coupling agent A151 were prepared according to weight parts.

[0046] 2. Preliminary modification: The high-density polyethylene was added to the polyimide powder and mixed with the polyamide resin, antimony oxide, compatibilizer MAH, and silicone rubber. The temperature was raised to 180 °C, and it was stirred with a kneader for 2 h.60 The Co source was used for irradiation modification at an irradiation dose of 200 kGy, and then accelerator EP-184, dimethyl phthalate, and silane coupling agent A151 were added. The mixture was kneaded in a kneader at 180 °C for 40 min, then at 190 °C for 30 min, and then at 150 °C for 2 h, and then extruded to obtain a high-temperature resistant material.

[0047] Comparative Example 2:

[0048] Preparation of cable material:

[0049] 1. Preparation of materials: Prepare 45 parts by weight of high-density polyethylene, 11 parts of polyamide resin, 9 parts of silicone rubber, 5 parts of polyimide powder, 1.5 parts of nano-aluminum oxide, 1.8 parts of antimony oxide, 1.5 parts of compatibilizer MAH, 1 part of accelerator EP-184, 2 parts of dimethyl phthalate, and 2.5 parts of silane coupling agent A151.

[0050] 2. Preliminary modification: The high-density polyethylene was mixed with nano-aluminum oxide and heated to 150 °C, and mixed and modified at a stirring speed of 1200 r / min for 20 min. Then, polyimide powder, polyamide resin, antimony oxide, compatibilizer MAH, and silicone rubber were added and heated to 180 °C. Stirred in a kneader for 2 h, and then accelerator EP-184, dimethyl phthalate, and silane coupling agent A151 were added. The mixture was kneaded in a kneader at 180 °C for 40 min, then at 190 °C for 30 min, and then at 150 °C for 2 h, and then extruded to obtain a high-temperature resistant material.

[0051] Comparative Example 3:

[0052] Preparation of cable material:

[0053] 1. Preparation of materials: Prepare 45 parts by weight of high-density polyethylene, 11 parts of polyamide resin, 9 parts of silicone rubber, 5 parts of polyimide powder, 1.8 parts of antimony oxide, 1.5 parts of compatibilizer MAH, 1 part of accelerator EP-184, 2 parts of dimethyl phthalate, and 2.5 parts of silane coupling agent A151.

[0054] 2. Preliminary modification: The high-density polyethylene was added to the polyimide powder, and polyamide resin, antimony oxide, compatibilizer MAH, and silicone rubber were mixed and heated to 180 °C. Stirred in a kneader for 2 h, and then accelerator EP-184, dimethyl phthalate, and silane coupling agent A151 were added. The mixture was kneaded in a kneader at 180 °C for 40 min, then at 190 °C for 30 min, and then at 150 °C for 2 h, and then extruded to obtain a high-temperature resistant material.

[0055] Detection:

[0056] The high-temperature resistance of the materials prepared in the above Examples 1-3 and Comparative Examples 1-3 was detected. The materials of each group were made into a thickness of 5 mm and thermally oxidized at 135 °C for 168 h. The mechanical properties and surface resistance of each group of materials before and after treatment were detected respectively. The results are shown in the following table:

[0057]

[0058] As can be seen from the above table, the materials prepared in Examples 1-3 have good high-temperature resistance, and the use of nano-alumina and radiation modification can effectively improve the high-temperature resistance of the materials, as well as improve the mechanical properties and service safety of the materials.

[0059] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0060] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A preparation method of a high-temperature resistant cable for an electric vehicle charging pile, characterized in that: The preparation method includes the following steps: ① Preparation of high-temperature resistant material: After heating the mixture of high-density polyethylene and nano-aluminum oxide to 150 °C for mixing and modification, polyimide powder, polyamide resin, flame retardant, compatibilizer, and silicone rubber are added and mixed and stirred at 180 °C for 2 h, and then irradiated and modified with 60 a Co source, and the irradiation dose is 200 kGy. Then, accelerator, plasticizer, and silane coupling agent are added for mixing and extrusion to obtain the high-temperature resistant material for standby; and the weight of each substance is: 40-50 parts of high-density polyethylene, 10-12 parts of polyamide resin, 8-10 parts of silicone rubber, 4-6 parts of polyimide powder, 1-2 parts of nano-aluminum oxide, 1.5-2 parts of flame retardant, 1-2 parts of compatibilizer, 0.8-1.2 parts of accelerator, 1-3 parts of plasticizer, and 2-3 parts of silane coupling agent; ② Conductor treatment: Select annealed copper wire as the conductor, twist multiple conductors, wrap them with non-woven fabric, and then extrude the wrapped conductor with the above-mentioned high-temperature resistant material to obtain a core for standby; ③ Filler treatment: Select polypropylene filling rope as the filling material, twist multiple polypropylene filling ropes, and wrap the outside with non-woven fabric to form a large filler for standby; ④ Cable stranding: Arrange multiple above-mentioned cores, large fillers, and ordinary polypropylene filling ropes, twist them, and extrude them with the above-mentioned high-temperature resistant material to obtain a preformed cable for standby; ⑤ Cable forming: Weave the outside of the above-mentioned preformed cable with annealed copper wire to form a shielding mesh layer, and then extrude the outside of the shielding mesh layer with the above-mentioned high-temperature resistant material to obtain a high-temperature resistant cable.

2. The preparation method of a high-temperature resistant cable for an electric vehicle charging pile according to claim 1, characterized in that: In the step ①, the mixing method is to mix at 180°C for 40 minutes first, then mix at 190°C for 30 minutes, and then mix at 150°C for 2 hours.

3. The preparation method of a high-temperature resistant cable for an automotive charging pile according to claim 1, characterized in that: The flame retardant is one or a combination of antimony oxide and zinc borate.

4. The preparation method of a high-temperature resistant cable for an automotive charging pile according to claim 1, characterized in that: In the step ②, the extrusion thickness of the high-temperature resistant material is 0.4mm ± 0.1mm, in the step ④, the extrusion thickness of the high-temperature resistant material is 0.6mm ± 0.1mm, and in the step ⑤, the extrusion thickness of the high-temperature resistant material is 4.5 ± 0.3mm.

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