Direct current liquid cooling charging cable and preparation method thereof

Abstract

The invention provides a direct current liquid cooling charging cable and a preparation method thereof, and relates to the technical field of electric vehicle charging cables, the cable comprises two power lines, a protection line and a liquid return pipe are arranged in a gap between the two power lines, and auxiliary power lines are arranged in gaps between the two power lines and the protection line. A control line and a signal line are respectively arranged in gaps between the two power lines and the liquid return pipe, filling pieces are arranged in gaps among the power lines, the protection line, the auxiliary power line, the control line, the signal line and the liquid return pipe, the power lines, the protection line, the auxiliary power line, the control line, the signal line, the liquid return pipe and the filling pieces are wrapped by a wrapping tape to form a wire core group, and an outer sheath is sleeved outside the wire core group. The hollow pipeline and the liquid return pipe are arranged in the conductor, the cable conductor is kept at a low temperature in the charging process through the liquid cooling technology, damage to a charging pile and a charging cable caused by heating of the conductor is overcome, the high-power rapid charging capacity of an electric vehicle is achieved, and the charging time of the electric vehicle is shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle charging cables, and in particular to a direct current liquid-cooled charging cable and a preparation method thereof. Background Art

[0002] In recent years, the new energy vehicle market has developed rapidly. Buses, taxis, logistics vehicles and shared cars have an urgent need for high-power fast charging, which shortens charging time, reduces operating costs and improves operating efficiency, directly leading to increased operating revenue. However, the small number of public charging parking spaces, low power battery range and long charging time are still key factors restricting the development of new energy vehicles; especially on highways, users hope to shorten charging time and reduce waiting, and the demand for fast charging is more urgent. Therefore, how to improve vehicle range and shorten charging time has become an industry consensus.

[0003] The electric vehicle charging cable is a carrier for transmitting electric energy between the electric vehicle and the charging pile. To achieve high-power fast charging of electric vehicles, not only the car battery is acceptable, but also the current sharing and control of the charging pile can be satisfied, but also a charging cable with high current transmission capacity is required. The high-power charging cables on the market are oil-cooled and water-cooled according to the different cooling media. Oil cooling is to design the insulation layer into an oil pipe, directly immerse the conductor part in oil, and increase the current carrying capacity through the circulation and heat dissipation of the insulating oil. This form of cable has a complex structure and high requirements for the conductor insulation material and structure. Another type is a water-cooled cable, which is to add some water pipes inside the cable. The cooling medium is a non-insulated liquid, which can be pure water or antifreeze, etc. The heat generated by the cable is conducted through the contact between the insulation and the water pipe. This conduction method is for the cable to enter the liquid, and then the heat is taken away by the circulation of the liquid. This is not the effect of direct cooling of the conductor. To this end, a better structure, better cooling effect, and high-power charging cable are designed to make up for the shortcomings of the existing technology. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a DC liquid-cooled charging cable and a preparation method thereof, so as to solve the defect of insufficient heat dissipation of the existing charging cable under high-power charging conditions. By adding a liquid return pipe inside the conductor and adopting liquid cooling technology, the cable conductor is kept at a low temperature during the charging process, and the damage to the charging pile, charging cable, and charging gun caused by the heating of the conductor is overcome, thereby realizing the high-power fast charging capability of the electric vehicle and shortening the charging time of the electric vehicle.

[0005] The technical solution adopted by the present invention is: A DC liquid-cooled charging cable, comprising two power lines, the two power lines are symmetrically arranged about the central axis of the cable, a protective line and a liquid return pipe are respectively arranged in the gap between the two power lines, an auxiliary power line is arranged in the gap between the two power lines and the protective line, a control line and a signal line are respectively arranged in the gap between the two power lines and the liquid return pipe, a filling piece is arranged in the gap between the power line, the protective line, the auxiliary power line, the control line, the signal line, and the liquid return pipe, the power line, the protective line, the auxiliary power line, the control line, the signal line, the liquid return pipe, and the filling piece are wrapped with a first wrapping tape to form a wire core group, and an outer sheath is arranged outside the wire core group.

[0006] Preferably, in the DC liquid-cooled charging cable, the power line comprises a hollow pipe, a first conductor, and a first insulating layer arranged in sequence from the inside to the outside; the hollow pipe comprises a first inner layer and a first outer layer arranged outside the first inner layer, the first conductor is made of metallic copper, and the cross-sectional area of ​​the first conductor is 50-240 mm 2 The first insulating layer is made of polyolefin rubber, and the thickness of the first insulating layer is 1.4 to 2.6 mm; the first conductor is formed by twisting a plurality of first strands, and the first strand is formed by twisting a first soft copper single wire with a diameter of 0.10 to 0.15 mm.

[0007] The hollow pipe adopts a two-layer structure, with the inner layer being made of non-metallic material and the outer layer being protected by metal material. The double-layer structure can withstand higher hydraulic pressure and temperature, while also ensuring the flexibility and plasticity of the pipe. The first conductor structure adopts a Category 6 soft conductor structure, which is twisted around the outer periphery of the hollow pipe to form the first conductor.

[0008] Preferably, in the DC liquid-cooled charging cable, the protective wire comprises a second conductor and a second insulating layer arranged outside the second conductor, and the cross-sectional area of ​​the second conductor is 35-240 mm 2 The structure of the second conductor is a Class 6 soft conductor structure, and the material of the second insulating layer is polyolefin rubber; the second conductor is formed by twisting multiple second strands, and the second strands are formed by twisting second soft copper single wires with a diameter of 0.10 to 0.15 mm.

[0009] Preferably, in the DC liquid-cooled charging cable, the auxiliary power line comprises a third conductor and a third insulating layer arranged outside the third conductor, and the cross-sectional area of ​​the third conductor is 2.5-6 mm 2 The structure of the third conductor is a Class 6 soft conductor structure, and the material of the third insulating layer is polyolefin rubber; the third conductor is formed by twisting multiple third strands, and the third strand is formed by twisting third soft copper single wires with a diameter of 0.10 to 0.15 mm.

[0010] The polyolefin rubber may be a polyolefin rubber mixture such as polyvinyl chloride, thermoplastic elastomer, ethylene propylene rubber, etc.

[0011] Preferably, in the DC liquid-cooled charging cable, the control line includes a first wire core, a second wrapping tape, and a sheath layer arranged in sequence from the inside to the outside; the first wire core is formed by twisting 2 to 6 core wires, and the core wire includes a fourth conductor and a fourth insulating layer arranged outside the fourth conductor.

[0012] Preferably, in the DC liquid-cooled charging cable, the fourth conductor is made of copper and has a cross-sectional area of ​​0.5 to 2.5 mm 2 The fourth conductor is formed by twisting a plurality of fourth strands of wire, and the fourth strand of wire is formed by twisting a fourth soft copper single wire with a diameter of 0.10 to 0.15 mm.

[0013] Preferably, in the DC liquid-cooled charging cable, the signal line includes a second core and a shielding layer arranged outside the second core, the second core is formed by twisting 2 to 3 pairs of data lines, the data line is formed by twisting two single-core wires, and the single-core wire includes a fifth conductor and a fifth insulating layer arranged outside the fifth conductor.

[0014] Preferably, in the DC liquid-cooled charging cable, the fifth conductor is made of metallic copper, the fifth conductor is made of fifth soft copper single wire with a diameter of 0.10-0.15 mm, and the cross-sectional area of ​​the fifth conductor is 0.25-1.0 mm 2 .

[0015] Preferably, in the DC liquid-cooled charging cable, the liquid return pipe is a hose, and the liquid return pipe includes a second inner layer and a second outer layer arranged on the outer periphery of the second inner layer.

[0016] The second inner layer is made of non-metallic material, and the second outer layer is made of metallic material. The liquid return conveying capacity of the liquid return pipe is more than 2.2 times that of the hollow pipe.

[0017] The present invention also provides a method for preparing a DC liquid-cooled charging cable, which comprises the following steps: Step S1. The first outer layer is sleeved on the outer periphery of the first inner layer to form a hollow tube, and the first soft copper single wire with a diameter of 0.10-0.15 mm is twisted into a cross-sectional area of ​​2.5-6 mm. 2 The first strands are formed by concentrically twisting the first strands in layers around the outer periphery of the hollow pipe to form a first conductor, and then a first insulating layer is extruded around the outer periphery of the first conductor to obtain a power line; Step S2: twist the second soft copper wire with a diameter of 0.10-0.15 mm into a cross-sectional area of ​​2.5-6 mm 2 The second strand of wire, then 2.5 ~ 6mm2 The plurality of second strands are layered and coaxially twisted to form a second conductor, and finally a second insulating layer is extruded around the outer periphery of the second conductor to obtain a protective wire; Step S3. Twist the third soft copper wire with a diameter of 0.10-0.15 mm into a wire with a cross-sectional area of ​​0.3-0.5 mm 2 The third strand of wire, then 0.3~0.5mm 2 A plurality of third strands are coaxially twisted to form a third conductor, and a third insulating layer is extruded around the outer periphery of the third conductor to obtain an auxiliary power line; Step S4. Twisting a fourth soft copper single wire with a diameter of 0.10 to 0.15 mm into a fourth strand, and then concentrically twisting a plurality of fourth strands to form a fourth conductor, wherein the cross-sectional area of ​​the fourth conductor is 0.5 to 2.5 mm 2 , a fourth insulating layer is extruded around the outer periphery of the fourth conductor to form a core wire, and 2 to 6 core wires are twisted to form a first wire core, and then a second wrapping tape is wrapped around the first wire core, and finally a sheath layer is wrapped around the second wrapping tape to obtain a control wire; Step S5. Twist the fifth soft copper wire with a diameter of 0.10-0.15 mm into a cross-sectional area of ​​0.25-1.0 mm 2 The fifth conductor is then extruded with a fifth insulating layer around the outer periphery of the fifth conductor to form a single core wire, and two single core wires are twisted together to form a data wire, and then 2 to 3 pairs of data wires are twisted together to form a second wire core, and finally a shielding layer is braided outside the second wire core to obtain a signal wire; Step S6. The second inner layer is covered with a second outer layer to form a liquid return pipe; Step S7. Twist the power line, protection line, auxiliary power line, control line, signal line, and liquid return pipe into a circular cable core, and fill the gaps between the power line, protection line, auxiliary power line, control line, signal line, and liquid return pipe in the circular cable core with fillers, then wrap a first wrapping tape around the outside of the circular cable core to form a core group, and finally extrude a sheath around the core group to obtain a DC liquid-cooled charging cable.

[0018] Advantages of the present invention: The DC liquid-cooled charging cable and preparation method thereof of the present invention provide a hollow pipe and a liquid return pipe inside the conductor and adopt liquid cooling technology to keep the cable conductor at a relatively low temperature during the charging process, thereby overcoming the damage of the conductor heating to the charging pile, charging cable, and charging gun, thereby achieving high-power rapid charging capability for electric vehicles and shortening the charging time of electric vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of the DC liquid-cooled charging cable of the present invention.

[0020] Figure 2 It is a schematic diagram of the cross-sectional structure of the DC liquid-cooled charging cable of the present invention.

[0021] Figure 3 It is a schematic diagram of the cross-sectional structure of the power line of the DC liquid-cooled charging cable of the present invention.

[0022] Figure 4 It is a schematic diagram of the cross-sectional structure of the DC liquid-cooled charging cable protection line of the present invention.

[0023] Figure 5 It is a schematic diagram of the cross-sectional structure of the auxiliary power line of the DC liquid-cooled charging cable of the present invention.

[0024] Figure 6 It is a schematic diagram of the cross-sectional structure of the DC liquid-cooled charging cable control line of the present invention.

[0025] Figure 7 It is a schematic diagram of the cross-sectional structure of the DC liquid-cooled charging cable signal line of the present invention.

[0026] Figure 8 It is a schematic diagram of the cross-sectional structure of the liquid return pipe of the DC liquid-cooled charging cable of the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with specific drawings and embodiments.

[0028] Example 1 A DC liquid-cooled charging cable, characterized in that it comprises two power lines 1, the two power lines 1 are symmetrically arranged about the central axis of the cable, a protection line 2 and a liquid return pipe 6 are respectively arranged in the gap between the two power lines 1, an auxiliary power line 3 is arranged at the gap between the two power lines 1 and the protection line 2, a control line 4 and a signal line 5 are respectively arranged at the gap between the two power lines 1 and the liquid return pipe 6, a filling piece 7 is arranged at the gap between the power line 1, the protection line 2, the auxiliary power line 3, the control line 4, the signal line 5, and the liquid return pipe 6, the power line 1, the protection line 2, the auxiliary power line 3, the control line 4, the signal line 5, and the liquid return pipe 6, the power line 1, the protection line 2, the auxiliary power line 3, the control line 4, the signal line 5, the liquid return pipe 6, and the filling piece 7 are wrapped by a first wrapping tape 8 to form a wire core group, an outer sheath 9 is arranged outside the wire core group, and the outer sheath 9 plays a role in protecting the cable.

[0029] The power line 1 includes a hollow pipe 1-1, a first conductor 1-2, and a first insulating layer 1-3 arranged in sequence from the inside to the outside; the hollow pipe 1-1 includes a first inner layer 1-1-1 and a first outer layer 1-1-2 arranged outside the first inner layer 1-1-1, the first conductor 1-2 is made of metal copper, and the cross-sectional area of ​​the first conductor 1-2 is 50 mm 2 The material of the first insulating layer 1-3 is thermoplastic elastomer TPE, and the thickness of the first insulating layer 1-3 is 1.45 mm; the first conductor 1-2 is composed of multiple cross-sectional areas of 2.5mm 2The first strand 1-2-2 is twisted together by twisting a first soft copper single wire 1-2-1 with a diameter of 0.10 mm.

[0030] The power line 1 hollow pipe 1-1 adopts a double-layer stainless steel hose, the first inner layer 1-1-1 adopts EPDM with an inner diameter of 3mm and a wall thickness of 0.5mm as the inner tube, the first outer layer 1-1-2 adopts a 304 stainless steel double-buckle hose with an inner diameter of 4mm and an outer diameter of 6mm as a protective tube, and EPDM is used as the inner tube of the first inner layer 1-1-1 to facilitate the flow and sealing of the coolant. The first outer layer 1-1-2 adopts a 304 stainless steel double-buckle hose to withstand higher hydraulic pressure and ensure the flexibility and plasticity of the hollow pipe 1-1, as well as the thermal conductivity between the coolant and the first conductor 1-2; the material of the first insulating layer 1-3 is thermoplastic elastomer TPE, and the thickness of the first insulating layer 1-3 is 1.4 mm. The two power lines 1 are identified by insulating layers of different colors, and the first insulating layers 1-3 are identified by blue and brown respectively.

[0031] The protection line 2 includes a second conductor 2-1 and a second insulating layer 2-2 arranged outside the second conductor 2-1. The cross-sectional area of ​​the second conductor 2-1 is 35 mm 2 The material of the second insulating layer 2-2 is thermoplastic elastomer TPE; the second conductor 2-1 is composed of multiple 2.5mm 2 The second strand is twisted 2-1-2, the 2.5mm 2 The second strand 2-1-2 is formed by twisting a second soft copper single wire 2-1-1 with a diameter of 0.10 mm.

[0032] The material of the second conductor 2-1 is metallic copper, the thickness of the second insulating layer 2-2 is 1.45 mm, and the second insulating layer 2-2 is identified by a combination of green and yellow colors.

[0033] The auxiliary power line 3 includes a third conductor 3-1 and a third insulating layer 3-2 arranged outside the third conductor 3-1. The cross-sectional area of ​​the third conductor 3-1 is 2.5 mm 2 The third insulating layer 3-2 is made of thermoplastic elastomer TPE; the third conductor 3-1 is composed of multiple conductors with a cross-sectional area of ​​0.3 mm 2 The third strand 3-1-2 is twisted, and the third strand 3-1-2 is twisted from a third soft copper single wire 3-1-1 with a diameter of 0.10 mm. The third conductor 3-1 is made of metallic copper, and the thickness of the third insulating layer 3-2 is 0.7 mm. In order to facilitate the identification of the auxiliary power line 3, the third insulating layer 3-2 of one core auxiliary power line 3 is gray, and the third insulating layer 3-2 of the other core auxiliary power line 3 is black, and different colors of insulating layers are used for identification.

[0034] The control line 4 includes a first core 4-1, a second wrapping tape 4-2, and a sheath layer 4-3 which are arranged in sequence from the inside to the outside; the first core 4-1 is formed by twisting three core wires 4-1-1, the core wire 4-1-1 includes a fourth conductor 4-1-11 and a fourth insulating layer 4-1-12 arranged outside the fourth conductor 4-1-11, and in order to facilitate identification of the core wire 4-1-1, the fourth insulating layer 4-1-12 adopts a different color.

[0035] The material of the fourth conductor 4-1-11 is metal copper, and the copper cross-sectional area of ​​the fourth conductor 4-1-11 is 0.5mm 2 , which is formed by twisting multiple fourth strands 4-1-111, and the fourth strand 4-1-111 is twisted by twisting fourth soft copper single wires 4-1-110 with a diameter of 0.15 mm.

[0036] The fourth conductor 4-1-11 is made of metallic copper, the fourth insulating layer 4-1-12 is 0.6 mm thick, the first core 4-1 is formed by twisting three core wires 4-1-1, and in order to easily distinguish the fourth conductor 4-1-11, the three core wires 4-1-1 are twisted and tied with a second wrapping tape 4-2 to bundle the core wires 4-1-1. The sheath layer 4-3 is made of ethylene propylene rubber, which plays a role in protecting the control line core.

[0037] The signal line 5 includes a second core 5-1 and a shielding layer 5-2 arranged outside the second core 5-1. The second core 5-1 is formed by twisting two pairs of data lines 5-1-2. The data line 5-1-2 is formed by twisting two single-core wires 5-1-1. The single-core wire 5-1-1 includes a fifth conductor 5-1-11 and a fifth insulating layer 5-1-12 arranged outside the fifth conductor 5-1-11. The material of the fifth conductor 5-1-11 is metallic copper. The fifth conductor 5-1-11 is twisted with a fifth soft copper single wire 5-1-110 with a diameter of 0.10 mm. The cross-sectional area of ​​the fifth conductor 5-1-11 is 0.25 mm. 2 .

[0038] The material of the fifth conductor 5-1-11 is metallic copper, the material of the fifth insulating layer 5-1-12 is polyethylene PE, the single core wire 5-1-1 is identified by color spectrum, two single core wires 5-1-1 are twisted into a data wire 5-1-2, the second core 5-1 has two pairs of data wires 5-1-2, the two pairs of data wires 5-1-2 are first twisted and then cabled to form the second core 5-1, and the shielding layer 5-2 is made of copper wire braided with a diameter of 0.10 mm.

[0039] The liquid return pipe 6 is a hose, and includes a second inner layer 6 - 1 and a second outer layer 6 - 2 arranged on the outer periphery of the second inner layer 6 - 1 .

[0040] The second inner layer 6-1 uses EPDM rubber with an inner diameter of 5mm and a wall thickness of 0.5mm as the inner tube, and the second outer layer 6-2 uses a 304 stainless steel double-buckle hose with an inner diameter of 6mm and an outer diameter of 8mm as the protective tube. The return liquid conveying capacity of the return liquid pipe 6 is 2.8 times the conveying capacity of the hollow pipe 1-1 of the power line 1. EPDM rubber is used as the inner tube of the second inner layer 6-1, which is convenient for the flow and sealing of the coolant. The second outer layer 6-2 uses a 304 stainless steel double-buckle hose to withstand higher hydraulic pressure and ensure the flexibility and plasticity of the return liquid pipe 6.

[0041] The method for preparing the DC liquid-cooled charging cable of this embodiment includes the following steps: Step S1. The first outer layer 1-1-2 is sleeved on the outer periphery of the first inner layer 1-1-1 to form a hollow tube 1-1, and the first soft copper single wire 1-2-1 with a diameter of 0.10 mm is twisted into a cross-sectional area of ​​2.5 mm 2 The first strand 1-2-2 is formed, and a plurality of first strands 1-2-2 are layered and coaxially twisted on the outer periphery of the hollow pipe 1-1 to form a first conductor 1-2, and then a first insulating layer 1-3 is extruded around the outer periphery of the first conductor 1-2 to obtain a power line 1; Step S2. Twist the second soft copper wire 2-1-1 with a diameter of 0.10 mm into a cross-sectional area of ​​2.5 mm 2 The second strand 2-1-2 will then have a cross-sectional area of ​​2.5 mm 2 The plurality of second strands 2-1-2 are layered and coaxially twisted to form a second conductor 2-1, and finally a second insulating layer 2-2 is extruded around the outer periphery of the second conductor 2-1 to obtain a protective wire 2; Step S3. Twist the third soft copper wire 3-1-1 with a diameter of 0.10 mm into a wire with a cross-sectional area of ​​0.3 mm 2 The third strand 3-1-2, then 0.3mm 2 A plurality of third strands 3-1-2 are coaxially twisted to form a third conductor 3-1, and a third insulating layer 3-2 is extruded around the outer periphery of the third conductor 3-1 to obtain an auxiliary power line 3; Step S4. Twist the fourth soft copper single wire 4-1-110 with a diameter of 0.10 mm into a fourth strand 4-1-111, and then concentrically twist a plurality of fourth strands 4-1-111 to form a fourth conductor 4-1-11, the copper cross-sectional area of ​​the fourth conductor 4-1-11 being 0.5 mm 2 , a fourth insulating layer 4-1-12 is extruded around the outer periphery of the fourth conductor 4-1-11 to form a core wire 4-1-1, the fourth insulating layers 4-1-12 of the three core wires 4-1-1 are distinguished by light blue, black and brown respectively, and the three core wires 4-1-1 are twisted to form a first core wire 4-1, and then a second wrapping tape 4-2 is twisted outside the first core wire 4-1, and finally a sheath layer 4-3 is coated outside the second wrapping tape 4-2 to obtain a control wire 4; Step S5. Twist the fifth soft copper wire 5-1-110 with a diameter of 0.10 mm into a cross-sectional area of ​​0.25 mm 2 The fifth conductor 5-1-11 is then extruded with a fifth insulating layer 5-1-12 around the outer periphery of the fifth conductor 5-1-11 to form a single core wire 5-1-1, and two single core wires 5-1-1 are twisted to form a data wire 5-1-2, and then two pairs of data wires 5-1-2 are twisted to form a second wire core 5-1, and finally a shielding layer 5-2 is braided outside the second wire core 5-1 to obtain a signal wire 5; Step S6. The second outer layer 6-2 is disposed outside the second inner layer 6-1 to form a liquid return pipe 6; Step S7. The power line 1, the protection line 2, the auxiliary power line 3, the control line 4, the signal line 5, and the return liquid pipe 6 are twisted into a circular cable core, and asbestos fibers are filled as fillers 7 in the gaps between the power line 1, the protection line 2, the auxiliary power line 3, the control line 4, the signal line 5, and the return liquid pipe 6 in the circular cable core to keep the relative positions of the components unchanged, so that the cable core structure is rounded, and the compression resistance and toughness of the cable are enhanced. Then, a first wrapping tape 8 is wrapped around the outside of the circular cable core to form a core group, and finally, a thermoplastic elastomer TPE is extruded outside the core group as a sheath 9 to protect the cable, and a 2×(50mm 2 +Ø6.0mm)+1×35mm 2 +2×2.5mm 2 +3×0.5mm 2 +2×(2×0.25mm 2 )+Ø8.0mm DC liquid-cooled charging cable, suitable for fast charging systems with DC 1000V, maximum current of 500A and below.

[0042] Example 2 A DC liquid-cooled charging cable, characterized in that it comprises two power lines 1, the two power lines 1 are symmetrically arranged about the central axis of the cable, a protection line 2 and a liquid return pipe 6 are respectively arranged in the gap between the two power lines 1, an auxiliary power line 3 is arranged at the gap between the two power lines 1 and the protection line 2, a control line 4 and a signal line 5 are respectively arranged at the gap between the two power lines 1 and the liquid return pipe 6, a filling piece 7 is arranged at the gap between the power line 1, the protection line 2, the auxiliary power line 3, the control line 4, the signal line 5, and the liquid return pipe 6, the power line 1, the protection line 2, the auxiliary power line 3, the control line 4, the signal line 5, and the liquid return pipe 6, the power line 1, the protection line 2, the auxiliary power line 3, the control line 4, the signal line 5, the liquid return pipe 6, and the filling piece 7 are wrapped by a first wrapping tape 8 to form a wire core group, an outer sheath 9 is arranged outside the wire core group, and the outer sheath 9 plays a role in protecting the cable.

[0043] The power line 1 includes a hollow pipe 1-1, a first conductor 1-2, and a first insulating layer 1-3 arranged in sequence from the inside to the outside; the hollow pipe 1-1 includes a first inner layer 1-1-1 and a first outer layer 1-1-2 arranged outside the first inner layer 1-1-1, the first conductor 1-2 is made of metal copper, and the cross-sectional area of ​​the first conductor 1-2 is 185mm 2 ; The material of the first insulating layer 1-3 is ethylene propylene rubber, and the thickness of the first insulating layer 1-3 is 2.6 mm; the first conductor 1-2 is composed of multiple cross-sectional areas of 6 mm 2 The first strand 1-2-2 is twisted together, and the first strand 1-2-2 is twisted together from a first soft copper single wire 1-2-1 with a diameter of 0.15 mm.

[0044] The power line 1 hollow pipe 1-1 adopts a double-layer stainless steel hose, the first inner layer 1-1-1 adopts EPDM rubber with an inner diameter of 5mm and a wall thickness of 0.5mm as the inner tube, and the first outer layer 1-1-2 adopts a 304 stainless steel double-buckle hose with an inner diameter of 6mm and an outer diameter of 8mm as a protective tube. EPDM rubber is used as the inner tube of the first inner layer 1-1-1 to facilitate the flow and sealing of the coolant. The first outer layer 1-1-2 adopts a 304 stainless steel double-buckle hose to withstand higher hydraulic pressure and ensure the flexibility and plasticity of the hollow pipe 1-1, as well as the thermal conductivity between the coolant and the first conductor 1-2; the first insulating layer 1-3 is made of EPDM rubber, and the two power lines 1 are identified by first insulating layers of different colors, and the first insulating layers 1-3 are identified by blue and brown respectively.

[0045] The protection line 2 includes a second conductor 2-1 and a second insulating layer 2-2 arranged outside the second conductor 2-1. The cross-sectional area of ​​the second conductor 2-1 is 150 mm 2 The second insulating layer 2-2 is made of ethylene propylene rubber; the second conductor 2-1 is made of multiple 6mm 2 The second strand is twisted 2-1-2, the 6mm 2 The second strand 2-1-2 is formed by twisting a second soft copper single wire 2-1-1 with a diameter of 0.15 mm.

[0046] The material of the second conductor 2-1 is metallic copper, the thickness of the second insulating layer 2-2 is 2.6 mm, and the second insulating layer 2-2 is identified by a combination of green and yellow colors.

[0047] The auxiliary power line 3 includes a third conductor 3-1 and a third insulating layer 3-2 arranged outside the third conductor 3-1. The cross-sectional area of ​​the third conductor 3-1 is 6 mm 2 The third insulating layer 3-2 is made of ethylene propylene rubber; the third conductor 3-1 is composed of multiple strands with a cross-sectional area of ​​0.5mm 2The third strand 3-1-2 is twisted into a Class 6 soft conductor structure. The third strand 3-1-2 is twisted from a third soft copper single wire 3-1-1 with a diameter of 0.15 mm. The third conductor 3-1 is made of metallic copper. The thickness of the third insulating layer 3-2 is 1.0 mm. In order to facilitate the identification of the auxiliary power line 3, the third insulating layer 3-2 of the auxiliary power line 3 of one core is gray, and the third insulating layer 3-2 of the auxiliary power line 3 of the other core is black, and different colors of insulating layers are used for identification.

[0048] The control line 4 includes a first core 4-1, a second wrapping tape 4-2, and a sheath layer 4-3, which are arranged in sequence from the inside to the outside; the first core 4-1 is formed by twisting 6 core wires 4-1-1, and the core wire 4-1-1 includes a fourth conductor 4-1-11 and a fourth insulating layer 4-1-12 arranged outside the fourth conductor 4-1-11. In order to facilitate the identification of the core wire 4-1-1, the fourth insulating layer 4-1-12 adopts a different color.

[0049] The material of the fourth conductor 4-1-11 is copper, and the cross-sectional area of ​​the fourth conductor 4-1-11 is 2.5 mm 2 , which is formed by twisting multiple fourth strands 4-1-111, and the fourth strand 4-1-111 is twisted by twisting fourth soft copper single wires 4-1-110 with a diameter of 0.15 mm.

[0050] The fourth conductor 4-1-11 is made of metallic copper, the fourth insulating layer 4-1-12 is 0.8 mm thick, the first core 4-1 is formed by twisting 6 core wires 4-1-1, and the 6 core wires 4-1-1 are twisted and bound with a second wrapping tape 4-2 to form a bundled core 4-1. The sheath layer 4-3 is made of ethylene propylene rubber, which plays a role in protecting and controlling the core wires.

[0051] The signal line 5 includes a second core 5-1 and a shielding layer 5-2 arranged outside the second core 5-1. The second core 5-1 is formed by twisting two pairs of data lines 5-1-2. The data line 5-1-2 is formed by twisting two single-core wires 5-1-1. The single-core wire 5-1-1 includes a fifth conductor 5-1-11 and a fifth insulating layer 5-1-12 arranged outside the fifth conductor 5-1-11. The material of the fifth conductor 5-1-11 is metallic copper. The fifth conductor 5-1-11 is twisted with a fifth soft copper single wire 5-1-110 with a diameter of 0.15 mm. The cross-sectional area of ​​the fifth conductor 5-1-11 is 1.5 mm. 2 .

[0052] The material of the fifth conductor 5-1-11 is metallic copper, the material of the fifth insulating layer 5-1-12 is cross-linked polyethylene XLPE, the single core wire 5-1-1 is identified by color, two single core wires 5-1-1 are twisted into a data wire 5-1-2, the second core 5-1 has two pairs of data wires 5-1-2, the two pairs of data wires 5-1-2 are first twisted and then cabled to form the second core 5-1, and the material of the shielding layer 5-2 is copper wire with a diameter of 0.10 mm.

[0053] The liquid return pipe 6 is a hose, and includes a second inner layer 6 - 1 and a second outer layer 6 - 2 arranged on the outer periphery of the second inner layer 6 - 1 .

[0054] The second inner layer 6-1 uses EPDM rubber with an inner diameter of 7.5mm and a wall thickness of 0.5mm as the inner tube, and the second outer layer 6-2 uses a 304 stainless steel double-buckle hose with an inner diameter of 8.5mm and an outer diameter of 11mm as the protective tube. The return liquid conveying capacity of the return liquid pipe 6 is 2.25 times the conveying capacity of the hollow pipe 1-1 of the power line 1. EPDM rubber is used as the inner tube of the second inner layer 6-1, which is convenient for the flow and sealing of the coolant. The second outer layer 6-2 uses a 304 stainless steel double-buckle hose to withstand higher hydraulic pressure and ensure the flexibility and plasticity of the return liquid pipe 6.

[0055] The method for preparing the DC liquid-cooled charging cable of this embodiment comprises the following steps: Step S1. The first outer layer 1-1-2 is sleeved on the outer periphery of the first inner layer 1-1-1 to form a hollow tube 1-1, and the first soft copper single wire 1-2-1 with a diameter of 0.15 mm is twisted into a cross-sectional area of ​​2.5 mm 2 The first strand 1-2-2 is formed, and a plurality of first strands 1-2-2 are layered and coaxially twisted on the outer periphery of the hollow pipe 1-1 to form a first conductor 1-2, and then a first insulating layer 1-3 is extruded around the outer periphery of the first conductor 1-2 to obtain a power line 1; Step S2. Twist the second soft copper wire 2-1-1 with a diameter of 0.15 mm into a cross-sectional area of ​​6 mm 2 The second strand 2-1-2, then the cross-sectional area is 6mm 2 The plurality of second strands 2-1-2 are layered and coaxially twisted to form a second conductor 2-1, and finally a second insulating layer 2-2 is extruded around the outer periphery of the second conductor 2-1 to obtain a protective wire 2; Step S3. Twist the third soft copper wire 3-1-1 with a diameter of 0.15 mm into a wire with a cross-sectional area of ​​0.5 mm 2 The third strand 3-1-2, then 0.5mm 2 A plurality of third strands 3-1-2 are coaxially twisted to form a third conductor 3-1, and a third insulating layer 3-2 is extruded around the outer periphery of the third conductor 3-1 to obtain an auxiliary power line 3; Step S4. Twist the fourth soft copper single wire 4-1-110 with a diameter of 0.15 mm into a fourth strand 4-1-111, and then concentrically twist a plurality of fourth strands 4-1-111 to form a fourth conductor 4-1-11, wherein the copper cross-sectional area of ​​the fourth conductor 4-1-11 is 2.5 mm 2 , a fourth insulating layer 4-1-12 is extruded around the outer periphery of the fourth conductor 4-1-11 to form a core wire 4-1-1. In order to facilitate the distinction of the fourth conductor 4-1-11, the fourth insulating layers 4-1-12 of the six core wires 4-1-1 are distinguished by yellow, green, blue, black, brown and gray respectively. The six core wires 4-1-1 are twisted to form a first core wire 4-1, and then a second wrapping tape 4-2 is twisted outside the first core wire 4-1. Finally, the sheath layer 4-3 is covered outside the second wrapping tape 4-2 to obtain a control wire 4; Step S5. Twist the fifth soft copper wire 5-1-110 with a diameter of 0.15 mm into a cross-sectional area of ​​1.0 mm 2 The fifth conductor 5-1-11 is then extruded with a fifth insulating layer 5-1-12 around the outer periphery of the fifth conductor 5-1-11 to form a single core wire 5-1-1, and two single core wires 5-1-1 are twisted to form a data wire 5-1-2, and then three pairs of data wires 5-1-2 are twisted to form a second wire core 5-1, and finally a shielding layer 5-2 is braided outside the second wire core 5-1 to obtain a signal wire 5; Step S6. The second outer layer 6-2 is disposed outside the second inner layer 6-1 to form a liquid return pipe 6; Step S7. The power line 1, the protection line 2, the auxiliary power line 3, the control line 4, the signal line 5, and the liquid return pipe 6 are twisted into a circular cable core, and asbestos fibers are filled as fillers 7 in the gaps between the power line 1, the protection line 2, the auxiliary power line 3, the control line 4, the signal line 5, and the liquid return pipe 6 in the circular cable core to keep the relative positions of the components unchanged, so that the cable core structure is rounded, and the compression resistance and toughness of the cable are enhanced. Then, a first wrapping tape 8 is wrapped around the outside of the circular cable core to form a core group, and finally, ethylene propylene rubber is extruded outside the core group as a sheath 9 to protect the cable, and a 2×(185mm 2 +Ø8.0mm)+1×150mm 2 +2×6mm 2 +6×2.5mm 2 +3×(2×1.0mm 2 )+Ø11.0mm DC liquid-cooled charging cable, suitable for fast charging systems with DC 1000V, maximum current 1500A capacity and below.

[0056] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A DC liquid-cooled charging cable, characterized in that: The invention comprises two power lines (1), the two power lines (1) are symmetrically arranged about the central axis of the cable, a protective line (2) and a liquid return pipe (6) are respectively arranged in the gap between the two power lines (1), an auxiliary power line (3) is arranged in the gap between the two power lines (1) and the protective line (2), a control line (4) and a signal line (5) are respectively arranged in the gap between the two power lines (1) and the liquid return pipe (6), a filling piece (7) is arranged in the gap between the power line (1), the protective line (2), the auxiliary power line (3), the control line (4), the signal line (5), and the liquid return pipe (6), and the power line (1), the protective line (2), the auxiliary power line (3), the control line (4), the signal line (5), the liquid return pipe (6), and the filling piece (7) are wrapped with a first wrapping tape (8) to form a wire core group, and an outer sheath (9) is arranged outside the wire core group.

2. The DC liquid-cooled charging cable according to claim 1, characterized in that: The power line (1) comprises a hollow pipe (1-1), a first conductor (1-2), and a first insulating layer (1-3) which are arranged in sequence from the inside to the outside; the hollow pipe (1-1) comprises a first inner layer (1-1-1) and a first outer layer (1-1-2) arranged outside the first inner layer (1-1-1); the material of the first conductor (1-2) is metallic copper; and the cross-sectional area of ​​the first conductor (1-2) is 50 to 240 mm 2 The first insulating layer (1-3) is made of polyolefin rubber and has a thickness of 1.4 to 2.6 mm. The first conductor (1-2) is formed by twisting a plurality of first strands (1-2-2), and the first strands (1-2-2) are formed by twisting a first soft copper single wire (1-2-1) with a diameter of 0.10 to 0.15 mm.

3. The DC liquid-cooled charging cable according to claim 1, characterized in that: The protective wire (2) comprises a second conductor (2-1) and a second insulating layer (2-2) arranged outside the second conductor (2-1); the cross-sectional area of ​​the second conductor (2-1) is 35 to 240 mm 2 The material of the second insulating layer (2-2) is polyolefin rubber; the second conductor (2-1) is formed by twisting a plurality of second strands (2-1-2), and the second strands (2-1-2) are formed by twisting second soft copper single wires (2-1-1) with a diameter of 0.10 to 0.15 mm.

4. The DC liquid-cooled charging cable according to claim 1, characterized in that: The auxiliary power line (3) comprises a third conductor (3-1) and a third insulating layer (3-2) arranged outside the third conductor (3-1); the cross-sectional area of ​​the third conductor (3-1) is 2.5 to 6 mm 2 The third insulating layer (3-2) is made of polyolefin rubber; the third conductor (3-1) is formed by twisting a plurality of third strands (3-1-2); the third strands (3-1-2) are formed by twisting third soft copper single wires (3-1-1) with a diameter of 0.10 to 0.15 mm.

5. The DC liquid-cooled charging cable according to claim 1, characterized in that: The control line (4) comprises a first wire core (4-1), a second wrapping tape (4-2), and a sheath layer (4-3) which are arranged in sequence from the inside to the outside; the first wire core (4-1) is formed by twisting 2 to 6 core wires (4-1-1), and the core wire (4-1-1) comprises a fourth conductor (4-1-11) and a fourth insulating layer (4-1-12) arranged outside the fourth conductor (4-1-11).

6. The DC liquid-cooled charging cable according to claim 5, characterized in that: The material of the fourth conductor (4-1-11) is metal copper, and the cross-sectional area of ​​the fourth conductor (4-1-11) is 0.5-2.5 mm 2 The fourth conductor (4-1-11) is formed by twisting a plurality of fourth strands (4-1-111), and the fourth strands (4-1-111) are formed by twisting fourth soft copper single wires (4-1-110) with a diameter of 0.10 to 0.15 mm.

7. The DC liquid-cooled charging cable according to claim 1, characterized in that: The signal line (5) comprises a second wire core (5-1) and a shielding layer (5-2) arranged outside the second wire core (5-1); the second wire core (5-1) is formed by twisting 2 to 3 pairs of data wires (5-1-2); the data wire (5-1-2) is formed by twisting two single-core wires (5-1-1); the single-core wire (5-1-1) comprises a fifth conductor (5-1-11) and a fifth insulating layer (5-1-12) arranged outside the fifth conductor (5-1-11).

8. The DC liquid-cooled charging cable according to claim 7, characterized in that: The material of the fifth conductor (5-1-11) is metallic copper. The fifth conductor (5-1-11) is formed by twisting fifth soft copper single wires (5-1-110) with a diameter of 0.10 to 0.15 mm. The cross-sectional area of ​​the fifth conductor (5-1-11) is 0.25 to 1.0 mm. 2 .

9. The DC liquid-cooled charging cable according to claim 1, characterized in that: The liquid return pipe (6) is a circular hose, and comprises a second inner layer (6-1) and a second outer layer (6-2) arranged on the outer periphery of the second inner layer (6-1).

10. The method for preparing a DC liquid-cooled charging cable according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step S1. The first outer layer (1-1-2) is sleeved on the outer periphery of the first inner layer (1-1-1) to form a hollow tube (1-1), and the first soft copper single wire (1-2-1) with a diameter of 0.10 to 0.15 mm is twisted into a cross-sectional area of ​​2.5 to 6 mm. 2 A first strand (1-2-2) is formed, and a plurality of first strands (1-2-2) are layered and coaxially twisted around the outer periphery of a hollow pipe (1-1) to form a first conductor (1-2), and then a first insulating layer (1-3) is extruded around the outer periphery of the first conductor (1-2) to obtain a power line (1); Step S2. Twist the second soft copper wire (2-1-1) with a diameter of 0.10-0.15 mm into a cross-sectional area of ​​2.5-6 mm 2 The second strand (2-1-2), then 2.5 ~ 6mm 2 A plurality of second strands (2-1-2) are twisted coaxially in layers to form a second conductor (2-1), and finally a second insulating layer (2-2) is extruded around the outer periphery of the second conductor (2-1) to obtain a protective wire (2); Step S3. Twist the third soft copper wire (3-1-1) with a diameter of 0.10-0.15 mm into a cross-sectional area of ​​0.3-0.5 mm 2 The third strand (3-1-2), then 0.3~0.5mm 2 A plurality of third strands (3-1-2) are coaxially twisted to form a third conductor (3-1), and a third insulating layer (3-2) is extruded around the outer periphery of the third conductor (3-1) to obtain an auxiliary power line (3); Step S4. Twisting a fourth soft copper single wire (4-1-110) with a diameter of 0.10 to 0.15 mm into a fourth strand (4-1-111), and then concentrically twisting a plurality of fourth strands (4-1-111) into a fourth conductor (4-1-11), wherein the cross-sectional area of ​​the fourth conductor (4-1-11) is 0.5 to 2.5 mm 2 , a fourth insulating layer (4-1-12) is extruded around the outer periphery of the fourth conductor (4-1-11) to form a core wire (4-1-1), and 2 to 6 core wires (4-1-1) are twisted to form a first wire core (4-1), and then a second wrapping tape (4-2) is wrapped around the first wire core (4-1), and finally a sheath layer (4-3) is wrapped around the second wrapping tape (4-2) to obtain a control wire (4); Step S5. Twist the fifth soft copper wire (5-1-110) with a diameter of 0.10-0.15 mm into a cross-sectional area of ​​0.25-1.0 mm 2 A fifth conductor (5-1-11) is provided, and then a fifth insulating layer (5-1-12) is extruded around the outer periphery of the fifth conductor (5-1-11) to form a single core wire (5-1-1), and two single core wires (5-1-1) are twisted together to form a data wire (5-1-2), and then 2 to 3 pairs of data wires (5-1-2) are twisted together to form a second wire core (5-1), and finally a shielding layer (5-2) is braided outside the second wire core (5-1) to obtain a signal wire (5); Step S6. The second outer layer (6-2) is disposed outside the second inner layer (6-1) to form a liquid return pipe (6); Step S7. The power line (1), the protection line (2), the auxiliary power line (3), the control line (4), the signal line (5), and the liquid return pipe (6) are twisted into a circular cable core, and the gaps between the power line (1), the protection line (2), the auxiliary power line (3), the control line (4), the signal line (5), and the liquid return pipe (6) in the circular cable core are filled with a filler (7), and then a first wrapping tape (8) is wrapped around the outside of the circular cable core to form a wire core group, and finally a sheath (9) is extruded outside the wire core group to obtain a DC liquid-cooled charging cable.

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