A high voltage cable for new energy vehicles

Abstract

A new energy vehicle high-voltage cable, characterized in that: the conductor is woven from a plurality of wires and rolled into a rectangular structure, each wire is formed with a first heat dissipation hole evenly spaced along its length; the insulating layer is made of a heat-vulcanized silicone rubber compound; the first tape layer is made of a composite copper foil tape; the braided layer is made of tinned copper wire, and is coated on the outside of the first tape layer through a braiding process, and the tinned copper wire is formed with a plurality of second heat dissipation holes evenly spaced along its length; the second tape layer is made of ePTFE tape; the third tape layer is made of copper foil Mylar tape; the sheath is made of silicon carbide composite silicone rubber material. The above-mentioned new energy vehicle high-voltage cable has the advantages of good heat dissipation performance, light weight, good comprehensive shielding performance, strong bending performance, good impact resistance and earthquake resistance.

Description

Technical Field

[0001] The present invention relates to a cable, and in particular to a high-voltage cable for new energy vehicles. Background Art

[0002] With the whirlwind popularity of new energy vehicles in China, national and local policy incentives for new energy vehicles, coupled with strict license plate controls and restrictions on traditional fuel vehicles in super first-tier cities such as Beijing, Shanghai, Guangzhou, Shenzhen and Hangzhou, have promoted the rapid development of new energy vehicles in my country.

[0003] Due to the increasingly rapid requirements for charging of new energy pure electric vehicles and the increasingly higher requirements for subsequent mileage after charging, the previous slow charging new energy charging and large-section and high-current new energy charging modes have encountered great technical challenges in terms of new energy charging timeliness, super-weighting and humanized operation convenience.

[0004] First of all, the high voltage and high current charging of new energy pure electric vehicles will put pressure on the weight of the charging gun to overload the new energy vehicles, which is very inconvenient to use. Generally, the weight of an EV car charging cable including the charging gun exceeds 20KG.

[0005] Secondly, when new energy pure electric vehicles meet the requirements of high voltage and high current, the heat dissipation bottleneck of the high-voltage pack, high-voltage box and high-voltage wire of the new energy vehicle battery is always severe, which directly affects the service life of the high-voltage battery, lithium battery and other energy batteries, and there are great hidden dangers to safe driving. In addition, replacing the battery is also a considerable high cost.

[0006] In order to improve the heat dissipation capacity of new energy vehicle batteries and fast charging, solve the bottleneck problem of lightweight normal charging for the general public, solve the battery heat loss and turbine loss caused by conductor heating in the process of high current, high voltage and fast charging, increase the compressive strength and bending strength of conventional copper conductors, solve the energy loss caused by the cable itself when the vehicle vibrates with high intensity, enhance the sound absorption and sound insulation effect of the vehicle, and enhance the shielding effect of the cable against high-frequency electromagnetic waves. In view of this, it is of great significance to focus on human and financial resources to develop a self-cooling new energy vehicle high-voltage cable product.

[0007] As an emerging type of liquid-cooled charging pile wire and cable, its biggest advantage is that it solves the problem of heat generation during fast charging, but the total weight has not been reduced much. In terms of overall weight and conductor cost, it still faces practical problems that need to be solved.

[0008] Furthermore, all current automotive high-voltage cables have two main structures: single-insulation structure with oxygen-free copper stranded multi-strand compact conductor + cross-linked PE material insulation, or oxygen-free copper stranded multi-strand compact conductor + gas phase high-resilient mixed flame-retardant silicone rubber; double-insulation structure with oxygen-free copper stranded multi-strand compact conductor + gas phase high-resilient mixed flame-retardant silicone rubber insulation (or single-sided aluminum foil) + high-shielded braided structure + high-temperature resistant aluminum foil Mylar shielding tape + gas phase high-resilient mixed flame-retardant silicone rubber sheath; whether it is single-insulation or double-insulation single-shielded and double-shielded structure cables, there are serious material and structural shortcomings in lightweight structural cost design and heat dissipation performance design (the overall weight of copper conductors is heavy, and the cost has always been high; fast-charging cables heat up, which directly affects the service life of automotive high-voltage cables and indirectly reduces the life span of rechargeable batteries).

[0009] Therefore, the material development, process development, structure development, production equipment development, and major function or product performance verification of a self-cooling new energy vehicle high-voltage cable all require revolutionary technological innovation and improvement. Summary of the invention

[0010] In order to overcome the shortcomings of the background technology, the present invention provides a new energy vehicle high-voltage cable.

[0011] The technical solution adopted by the present invention is: a new energy vehicle high-voltage cable, comprising a cable core, a second tape layer, a third tape layer, and a sheath arranged in sequence from the inside to the outside; the cable core comprises 4 core wires, each of which comprises a conductor, an insulating layer, a first tape layer, and a braided layer arranged in sequence from the inside to the outside;

[0012] The conductor is woven from a plurality of wires and rolled into a rectangular structure, and each wire is provided with first heat dissipation holes evenly spaced along its length;

[0013] The insulating layer is made of heat-cured silicone rubber compound and is formed outside the conductor through an extrusion process;

[0014] The first wrapping tape layer is made of composite copper foil tape and is wrapped around the insulating layer by a wrapping process;

[0015] The braided layer is made of tinned copper wire and is coated outside the first wrapping layer through a braiding process. The tinned copper wire is formed with a plurality of second heat dissipation holes evenly spaced along its length direction;

[0016] The second tape layer is made of ePTFE tape and is coated on the outside of the cable core by a dragging process;

[0017] The third wrapping tape layer is made of copper foil Mylar tape and is wrapped outside the second wrapping tape layer by a drag wrapping process;

[0018] The sheath is made of silicon carbide composite silicone rubber material and is formed outside the third wrapping layer through an extrusion process.

[0019] The wire is made of nickel-plated oxygen-free copper alloy, and its cross section is a rectangular structure with a thickness of 0.52 mm, a width of 0.52 mm and rounded corners. The aperture of the first heat dissipation hole is 0.2 mm, and the spacing between adjacent first heat dissipation holes is 7.8 mm.

[0020] The conductor comprises 24 wires, and the processing method of the conductor comprises the following steps:

[0021] Step 1: 24 wires are braided by a 36-spindle heavy-duty braiding machine with a braiding pitch of 36 mm and a braiding angle of 45 degrees. After the braiding is completed, the wires are collected first;

[0022] Step 2: Pay out the woven semi-finished product obtained in step 1, and calender the woven semi-finished product into a flat rectangular structure of 0.49 mm thick and 1.98 mm wide through a rectangular calendering mold with a thickness of 0.49 mm and a width of 1.98 mm, and then wind it up after calendering.

[0023] The composite copper foil tape comprises a copper foil tape, one side of which is coated with a heat dissipation coating, and the other side is adhered with a release film by gluing. The size of the composite copper foil tape is 13-15 mm wide, 0.05-0.11 mm thick, and has a shielding rate of 125%.

[0024] The cross section of the tinned copper wire is a rectangular structure with a width of 0.52 mm and a thickness of 0.52 mm. The aperture of the second heat dissipation hole is 0.2 mm, and the spacing between adjacent second heat dissipation holes is 7.8 mm.

[0025] The braiding pitch of the braided layer is 38 mm, the braiding angle is 45 degrees, and the shielding rate is above 90%.

[0026] The dimensions of the ePTFE tape are 15-18 mm wide, 0.05-0.4 mm thick, and a shielding rate of 135%.

[0027] The dimensions of the copper foil Mylar tape are 20-25 mm wide, 0.035 mm thick, and a shielding rate of 125%.

[0028] The SiC powder addition ratio of the silicon carbide composite silicone rubber material is 0.035%.

[0029] The beneficial effects of the present invention are:

[0030] 1. The conductor wires and the tinned copper wires of the braided layer are formed with evenly spaced heat dissipation holes in the length direction. The conductor has a large specific surface area. During high-power and high-current charging, when heat flows through, its large specific surface area causes the fluid dispersed in it to produce complex three-dimensional flow, thus having a higher self-heat dissipation capacity; secondly, the composite copper foil tape, copper foil Mylar tape, and silicon carbide composite silicone rubber materials have good heat dissipation performance. High heat dissipation performance materials are selected from the inside to the outside, so that the heat dissipation efficiency is improved automatically during the fast charging process;

[0031] 2. The conductor wires and the tinned copper wires of the braided layer are formed with evenly spaced heat dissipation holes in the length direction, which realizes easy normal weight reduction, greatly reduces the overall weight and realizes lightweight design;

[0032] 3. Composite copper foil tape, ePTFE tape, copper foil Mylar tape, and silicon carbide composite silicone rubber materials have good comprehensive shielding performance and bending performance, and can meet the practical requirements of new energy vehicle batteries and high-voltage space wiring in narrow spaces;

[0033] 4. Each core wire is provided with an independent braided layer, which realizes the function of independent signal isolation and independent unidirectional rapid transmission between the core wires. At the same time, due to the existence of heat dissipation holes, when the high-frequency electromagnetic field passes through, it will generate an induced electromotive force and form an induced eddy current, which will offset the eddy current magnetic field in the opposite direction of the original magnetic field, thereby achieving a reliable shielding effect of the electromagnetic field and achieving a good electromagnetic wave shielding effect;

[0034] 5. Since the conductor is rolled into a rectangle, each core wire is also rectangular, and the force-bearing area is large. When the vehicle is running at high speed and vibrating, the combined resistance from the four corners and eight sides of the rectangle can be resolved, so that each core wire is evenly stressed, achieving the purpose of shock absorption and balance. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of the structure of a high-voltage cable for new energy vehicles according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0037] like Figure 1 As shown, a new energy vehicle high-voltage cable includes a cable core, a second tape layer 5, a third tape layer 6, and a sheath 7 arranged in sequence from the inside to the outside. The cable core includes 4 core wires, and each core wire includes a conductor 1, an insulating layer 2, a first tape layer 3, and a braided layer 4 arranged in sequence from the inside to the outside.

[0038] The wire is made of nickel-plated oxygen-free copper alloy, and its cross-section is a rectangular structure with a thickness of 0.52 mm, a width of 0.52 mm and rounded corners. Each wire is formed with first heat dissipation holes evenly spaced along its length. The aperture of the first heat dissipation holes is 0.2 mm, and the spacing between adjacent first heat dissipation holes is 7.8 mm.

[0039] The conductor 1 comprises 24 wires, and the processing method of the conductor comprises the following steps:

[0040] Step 1: 24 wires are braided by a 36-spindle heavy-duty braiding machine with a braiding pitch of 36 mm and a braiding angle of 45 degrees. After the braiding is completed, the wires are collected first;

[0041] Step 2: Pay out the braided semi-finished product obtained in step 1, and roll the braided semi-finished product through a rectangular rolling forming die with a thickness of 0.49 mm and a width of 1.98 mm to form a flat rectangular structure with a thickness of 0.49 mm and a width of 1.98 mm, and then wind up the braided semi-finished product after rolling.

[0042] Among them, before entering the rectangular calendering forming die, the braided semi-finished product can first pass through the first positioning rectangular die and the second pressing and shaping die to ensure the calendering forming quality.

[0043] The conductor 1 has the characteristics of corrosion resistance, high modulus, small thermal expansion coefficient, good electrical and thermal conductivity, strong impact resistance, and at the same time, a first heat dissipation hole is provided to increase the specific surface area, improve the heat dissipation performance, and has vibration absorption and sound absorption performance.

[0044] The insulating layer 2 is made of heat-vulcanized silicone rubber compound and is formed outside the conductor 1 through an extrusion process. The heat-vulcanized silicone rubber compound is resistant to salt spray corrosion, atmospheric ozone, sunlight, and special outdoor high temperature environments. It has high tensile strength and high tear strength, excellent comprehensive performance, good mechanical strength, excellent electrical properties, and meets ROHS10 and REACH environmental performance tests.

[0045] The first wrapping layer 3 is made of composite copper foil and is wrapped around the insulating layer 2 by a drag wrapping process. The composite copper foil includes a copper foil, one side of which is coated with a heat dissipation coating and the other side is glued with a release film. The size of the composite copper foil is 13-15 mm wide, 0.05-0.11 mm thick, and has a shielding rate of 125%. It has the advantages of strong adhesion, good heat dissipation effect, and excellent shielding performance.

[0046] The braided layer 4 is made of tinned copper wire, and the cross-section of the tinned copper wire is a rectangular structure with a width of 0.52mm and a diameter of 0.52mm. The tinned copper wire is formed with a number of evenly spaced second heat dissipation holes along its length. The aperture of the second heat dissipation holes is 0.2mm, and the spacing between adjacent second heat dissipation holes is 7.8mm.

[0047] The tinned copper wire is coated on the outside of the first wrapping layer 3 by a braiding process, the braiding pitch of the braided layer 4 is 38 mm, the braiding angle is 45 degrees, and the shielding rate is above 90%.

[0048] The braided layer 4 has the characteristics of corrosion resistance, high modulus, and small thermal expansion coefficient, good electrical and thermal conductivity, and strong impact resistance. At the same time, a second heat dissipation hole is arranged to increase the specific surface area, improve the heat dissipation performance, and has vibration and sound absorption performance, and has excellent electromagnetic energy heat dissipation effect.

[0049] The second tape layer 5 is made of ePTFE tape and is coated on the outside of the cable core by a dragging process. The ePTFE tape is soft and smooth, has a low dielectric constant, and has excellent temperature resistance. It can be used for a long time in a high-voltage battery pack of a car and in a high temperature range in summer. It has low dielectric loss, thin thickness, low density, light weight, high and low temperature resistance, corrosion resistance, friction resistance, good wear resistance, and uniform density.

[0050] The third wrapping layer 6 is made of copper foil Mylar tape, and is coated on the outside of the second wrapping layer 5 through a drag wrapping process. The copper foil Mylar tape includes copper foil, and the surface of the copper foil is bonded to a PET polyester film through an adhesive. It has low surface oxygen characteristics, and also has high strength, high flexibility and ductility, good conductivity, good heat dissipation, and a comprehensive application effect of good surface gloss.

[0051] The sheath 7 is made of silicon carbide composite silicone rubber material and is formed outside the third wrapping layer 6 through an extrusion process, wherein the SiC powder added in the silicon carbide composite silicone rubber material is 0.035%, which greatly improves the heat dissipation capacity of the wire structure.

[0052] The above-mentioned sheath 7 is resistant to ozone, aging, ultraviolet radiation, high and low temperature, pulling, and flexure, and has a small shrinkage rate; due to the addition of a certain proportion of Sic powder, the thermal conductivity of the sheath itself is greatly improved, the thermal resistance value of the sheath is reduced, and the temperature resistance effect is higher; and the performance of the sheath's breakdown voltage resistance is increased. Secondly, the high resilience and compression deformation resistance of the sheath are increased. According to the results of the on-site spark test, the sheath can withstand a maximum spark voltage of more than 15KV, fully meeting the UL VW-1 flame retardant requirements and ROHS10 items and REACH environmental protection performance testing.

[0053] The above-mentioned new energy vehicle high voltage cables are mainly used in new energy vehicles and new energy vehicle charging piles, and their advantages are:

[0054] 1. The conductor wires and the tinned copper wires of the braided layer are formed with evenly spaced heat dissipation holes in the length direction. The conductor has a large specific surface area. During high-power and high-current charging, when heat flows through, its large specific surface area causes the fluid dispersed in it to produce complex three-dimensional flow, thus having a higher self-heat dissipation capacity; secondly, the composite copper foil tape, copper foil Mylar tape, and silicon carbide composite silicone rubber materials have good heat dissipation performance. High heat dissipation performance materials are selected from the inside to the outside, so that the heat dissipation efficiency is improved automatically during the fast charging process;

[0055] 2. The conductor wires and the tinned copper wires of the braided layer are formed with evenly spaced heat dissipation holes in the length direction, which realizes easy normal weight reduction, greatly reduces the overall weight and realizes lightweight design;

[0056] 3. Composite copper foil tape, ePTFE tape, copper foil Mylar tape, and silicon carbide composite silicone rubber materials have good comprehensive shielding performance and bending performance, and can meet the practical requirements of new energy vehicle batteries and high-voltage space wiring in narrow spaces;

[0057] 4. Each core wire is provided with an independent braided layer, which realizes the function of independent signal isolation and independent unidirectional rapid transmission between the core wires. At the same time, due to the existence of heat dissipation holes, when the high-frequency electromagnetic field passes through, it will generate an induced electromotive force and form an induced eddy current, which will offset the eddy current magnetic field in the opposite direction of the original magnetic field, thereby achieving a reliable shielding effect of the electromagnetic field and achieving a good electromagnetic wave shielding effect;

[0058] 5. Since the conductor is rolled into a rectangle, each core wire is also rectangular, and the force-bearing area is large. When the vehicle is running at high speed and vibrating, the combined resistance from the four corners and eight sides of the rectangle can be resolved, so that each core wire is evenly stressed, achieving the purpose of shock absorption and balance.

[0059] Technical personnel should note that although the present invention has been described according to the above specific implementation methods, the inventive concept of the present invention is not limited to this invention, and any modification using the inventive concept will be included in the scope of protection of this patent.

Claims

1. A new energy vehicle high voltage cable, comprising a cable core, a second tape layer, a third tape layer, and a sheath arranged in sequence from the inside to the outside; characterized in that: The cable core comprises four core wires, each core wire comprising a conductor (1), an insulating layer (2), a first tape layer (3), and a braided layer (4) which are arranged in sequence from the inside to the outside; The conductor (1) is woven from a plurality of wires and rolled into a rectangular structure, the cross section of the wires being a quasi-rectangular structure with a thickness of 0.52 mm, a width of 0.52 mm and rounded corners, and each wire is formed with first heat dissipation holes evenly spaced along its length direction; The insulating layer (2) is made of a heat-vulcanized silicone rubber compound and is formed outside the conductor (1) through an extrusion process; The first wrapping tape layer (3) is made of a composite copper foil tape and is wrapped around the outside of the insulating layer (2) by a wrapping process; The braided layer (4) is made of tinned copper wire and is coated on the outside of the first wrapping layer (3) through a braiding process, and the tinned copper wire is formed with a plurality of second heat dissipation holes evenly spaced along its length direction; The second tape layer (5) is made of ePTFE tape and is coated on the outside of the cable core by a dragging process; The third wrapping tape layer (6) is made of copper foil Mylar wrapping tape and is wrapped around the second wrapping tape layer (5) by a drag wrapping process; The sheath (7) is made of silicon carbide composite silicone rubber material and is formed outside the third wrapping layer (6) through an extrusion process.

2. The new energy vehicle high voltage cable according to claim 1, characterized in that: The wire is made of nickel-plated oxygen-free copper alloy, the diameter of the first heat dissipation hole is 0.2 mm, and the spacing between adjacent first heat dissipation holes is 7.8 mm.

3. The new energy vehicle high voltage cable according to claim 1 or 2, characterized in that: The conductor (1) comprises 24 wires, and the conductor processing method comprises the following steps: Step 1: 24 wires are braided by a 36-spindle heavy-duty braiding machine with a braiding pitch of 36 mm and a braiding angle of 45 degrees. After the braiding is completed, the wires are collected first; Step 2: Pay out the braided semi-finished product obtained in step 1, and calender the braided semi-finished product into a flat rectangular structure with a thickness of 0.49 mm and a width of 1.98 mm through a rectangular calendering die with a thickness of 0.49 mm and a width of 1.98 mm, and then take up the wire after calendering.

4. The new energy vehicle high voltage cable according to claim 1, characterized in that: The composite copper foil tape comprises a copper foil tape, one side of which is coated with a heat dissipation coating, and the other side is adhered with a release film by gluing. The size of the composite copper foil tape is 13 to 15 mm wide, 0.05 to 0.11 mm thick, and has a shielding rate of 125%.

5. The new energy vehicle high voltage cable according to claim 1, characterized in that: The cross section of the tinned copper wire is a rectangular structure with a width of 0.52 mm and a thickness of 0.52 mm. The diameter of the second heat dissipation hole is 0.2 mm, and the spacing between adjacent second heat dissipation holes is 7.8 mm.

6. The new energy vehicle high voltage cable according to claim 1 or 5, characterized in that: The braiding pitch of the braided layer (4) is 38 mm, the braiding angle is 45 degrees, and the shielding rate is above 90%.

7. The new energy vehicle high voltage cable according to claim 1, characterized in that: The dimensions of the ePTFE tape are 15 to 18 mm wide, 0.05 to 0.4 mm thick, and a shielding rate of 135%.

8. The new energy vehicle high voltage cable according to claim 1, characterized in that: The dimensions of the copper foil Mylar tape are 20-25 mm wide, 0.035 mm thick, and a shielding rate of 125%.

9. The new energy vehicle high voltage cable according to claim 1, characterized in that: The SiC powder addition ratio of the silicon carbide composite silicone rubber material is 0.035%.

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