A wire drawing process for the copper conductor of a liquid-cooled ultra-fast charging pile cable

Abstract

The present invention discloses a wire drawing process for the copper conductor of a liquid-cooled ultra-fast charging pile cable, including a copper wire drawing process, and the copper wire drawing process specifically includes a wire drawing speed control process and the concentration of wire drawing oil. By adding an appropriate dose of antioxidant, copper sulfate is used, which is usually used to form a protective oxide film to prevent the oxidation of copper materials. Ethylenediamine is used, which is commonly used as a corrosion inhibitor to slow down the corrosion rate of copper. Copper phosphate is used, which can be used as a rust inhibitor to form a protective oxide film. Preservatives and surfactants are used to improve the adhesion and corrosion resistance of the coating, forming a protective film on the surface of the copper wire to isolate the air and reduce the oxidation of the copper wire. At the same time, the antioxidant can also reduce the friction on the surface of the copper wire, reduce wear, improve the wire drawing efficiency and product quality, and avoid the problem that during the production process of copper wire drawing, the copper wire will rub against components such as dies and guide wheels, resulting in an increase in the surface temperature of the copper wire and easy oxidation.

Description

Technical Field

[0001] The present invention relates to the technical field of cable copper conductor production, and specifically to a wire drawing process for a liquid-cooled ultra-fast charging pile cable copper conductor. Background Art

[0002] Liquid-cooled ultra-fast charging technology is an advanced charging technology. By adopting liquid cooling technology in charging equipment, it can charge more quickly and efficiently. The liquid-cooled ultra-fast charging technology solves the problem that heat dissipation and high-power charging cannot be achieved simultaneously, and speeds up the charging speed. During the charging process, a large amount of heat is generated by high-power current. If the heat cannot be dissipated in time, it will damage the battery and the charging pile. Conventional charging piles use air-cooling modules for heat dissipation, and the amount of heat that can be taken away is limited. The liquid-cooled ultra-fast charging technology adds a liquid-cooling channel between the cable and the charging gun. The coolant or oil-cooled insulating oil in it completes the circulation under the push of a power pump, taking away more heat, which means that the power of the charging pile can be further increased. In addition, the liquid-cooled ultra-fast charging technology also has the characteristics of high efficiency, stability and safety, and is applicable to various types of batteries, including lithium-ion batteries, nickel-metal hydride batteries, etc.

[0003] The liquid-cooled charging pile sets up a special liquid circulation channel between the cable and the charging gun. A coolant for heat dissipation is added to the channel, and the coolant is pushed to circulate by a power pump to take away the heat generated during the charging process, so as to improve the cable transmission power and achieve high-power charging.

[0004] Compared with the traditional direct ventilation heat dissipation method, liquid-cooled heat dissipation can completely isolate the inside and outside of the module, avoiding the direct contact between the internal electronic devices and dust, salt spray, water vapor, flammable and explosive gases, etc. in the outside world, and can improve the protection level to IP65, with better safety.

[0005] At present, in the process of copper wire drawing production for the cable copper conductor of liquid-cooled ultra-fast charging piles, the control effects of the existing technology on the wire drawing speed, the concentration, temperature and PH value of the wire drawing oil, adding a suitable dose of antioxidant, and the wire feeding and take-up tension parameters during the copper wire stranding production process are not particularly good, which is not conducive to maintaining the stability of the process and affects the consistency of product quality. Therefore, we need to provide a wire drawing process for the cable copper conductor of liquid-cooled ultra-fast charging piles. Generally, it is necessary to comprehensively consider various factors such as copper wire material, product specifications, die conditions, wire drawing oil performance, and equipment performance, and find a suitable production speed balance point to achieve the best combination of production efficiency, product quality and stable equipment operation. Summary of the Invention

[0006] (1) Technical Problems to be Solved

[0007] In view of the deficiencies of the prior art, the present invention provides a wire drawing process for a liquid-cooled ultra-fast charging pile cable copper conductor, which solves the problems raised in the above background.

[0008] (2) Technical Solution

[0009] To achieve the above object, the present invention provides the following technical solution: A wire drawing process for the copper conductor of a liquid-cooled ultra-fast charging pile cable, including a copper wire drawing process, and the copper wire drawing process specifically includes a wire drawing speed control process, and the control of the concentration, temperature and pH value of the wire drawing oil, and specifically includes the following method steps:

[0010] Step 1: Use a wire drawing machine set to draw the copper conductor material into a single wire. Take the copper conductor material as the wire feed, and draw it into a copper single wire through a wire drawing machine set with a round core.

[0011] Step 2: Through a stranding machine, arrange several copper single wires obtained in Step 1 around the round core wire and strand them into a wire blank, so that the arc surfaces of the copper single wires face the round core wire. Then, pre-twist the copper single wires. The copper single wires rotate around their own wire shafts to ensure that the small arc surfaces of the copper single wires face the core wire. Finally, each copper single wire and the core wire converge at the forming and bunching die and are stranded to form a copper wire blank.

[0012] Step 3: When using a double-head wire drawing machine for wire drawing, the concentration of the wire drawing oil is 15-19%; the temperature of the wire drawing oil is 35-45°C; the pH value of the wire drawing oil is 8.5-9.5; when using a multi-head wire drawing machine for wire drawing, the concentration of the wire drawing oil is 4-8%; the temperature of the wire drawing oil is 35-45°C; the pH value of the wire drawing oil is 8.5-9.5.

[0013] Step 4: Put the copper wire blank into an annealing furnace and heat it up to 300-330°C, keep it warm for 6-10 hours, and then let it stand and cool naturally to room temperature to become a semi-finished copper wire.

[0014] Step 5: Wrap an inner insulating layer, a protective layer, and an insulating sheath around the semi-finished copper wire. After passing the electrical detection, it is a copper wire conductor.

[0015] Preferably, the diameter of the copper single wire is 0.20-1.8 mm, the speed of the wire drawing machine set is controlled at 22-26 m / s, and the wire drawing machine set can use a double-head wire drawing machine or a multi-head wire drawing machine.

[0016] Preferably, the rotation angle of the copper single wire around its own wire shaft is 180°-360°, and the pre-twist direction is opposite to the stranding rotation direction.

[0017] Preferably, in Step 2, the stranding pitch diameter ratio of the outermost layer of strands is 8:20, and the stranding pitch diameter ratio of each layer of strands gradually increases from the outside to the inside, and the difference in the stranding pitch diameter ratio between adjacent two layers is 3:8.

[0018] Preferably, in the second step, a copper conductor with a specification of 186 / 0.20AS (1*30 + 6*26) and a threading method of 2*6&8+2*7 / 1+6 is used. When bunch-stranding, the wire release tension of each bus bar is 15N ± 5N, and the wire take-up tension is 30N ± 5N; when double-stranding, the wire release tension of each bus bar is 35N ± 5N, and the wire take-up tension is 100N ± 5N.

[0019] Preferably, in the fourth step, specifically, the wire blank is placed in a preheated annealing furnace and heated to 310 - 330°C, held for 2 - 3 hours, then heated to 340 - 370°C and held for 2 hours. Then, the wire blank after heating is cooled at a rate of 12 - 20°C per 0.1 hour to a temperature of 250 - 270°C and held for 2 - 3 hours. Finally, the wire blank is taken out of the annealing furnace and left to cool naturally to room temperature to obtain a semi-finished copper wire.

[0020] Preferably, in the fourth step, by adding a suitable dose of antioxidant to the original annealing liquid formulation, a protective film is formed on the surface of the copper wire to isolate air and reduce the oxidation of the copper wire; at the same time, the antioxidant also reduces the friction on the surface of the copper wire, reduces wear, and improves the drawing efficiency and product quality.

[0021] Preferably, the antioxidant comprises raw materials in the following weight ratio: sulfate compound 1% - 10%, organic amine compound 0.5% - 5%, phosphate compound 0.1% - 2%, mixture of preservative and surfactant 0.1% - 1%.

[0022] Preferably, the sulfate compound is preferably copper sulfate, the organic amine compound is preferably ethylenediamine, and the phosphate compound is preferably copper phosphate.

[0023] Preferably, when using a double-head drawing machine, the daily antioxidant addition amount is 150 ml / day in winter (January - May and October - December) and 300 ml / day in summer (June - September); when using a multi-head drawing machine, the daily antioxidant addition amount is 400 ml.

[0024] (III) Beneficial Effects

[0025] Compared with the prior art, the present invention provides a wire drawing process for the copper conductor of a liquid-cooled ultra-fast charging pile cable, having the following beneficial effects:

[0026] 1. For this wire drawing process of the copper conductor of the liquid-cooled ultra-fast charging pile cable, when using a double-head drawing machine to produce 1.8 mm copper wire, the best wire drawing speed is 23 - 26 m / s, and when using a multi-head drawing machine to produce 0.20 mm copper wire, the wire drawing speed needs to be controlled at 22 - 26 m / s.

[0027] 2. The wire drawing process of the copper conductor of the liquid-cooled super-charging pile cable effectively controls the wire drawing oil concentration, wire drawing oil temperature and wire drawing oil pH value of the double-head wire drawing machine and the multi-head wire drawing machine to effectively avoid the problem that when the concentration is too high, the viscosity of the wire drawing oil may increase, the resistance in the wire drawing process may increase, the wire drawing energy consumption may increase, the surface quality of the product may be affected, and there may be problems such as unevenness. When the concentration is too low, the lubrication effect is not good, which may easily cause greater friction between the copper wire and the mold and other components, resulting in scratches, heating and even wire breakage on the copper wire surface; the cooling effect is insufficient and the heat generated by friction cannot be effectively taken away. If the temperature is too high, the wire drawing oil will oxidize and volatilize, affecting the wire drawing quality; if the temperature is too low, the viscosity of the wire drawing oil will increase, affecting the wire drawing efficiency. Good control of the pH value is conducive to inhibiting the production of bacteria. If the pH value is too high, the alkalinity of the wire drawing oil will increase, affecting the wire drawing efficiency; if the pH value is too low, the acidity of the wire drawing oil will increase, affecting the wire drawing quality.

[0028] 3. The wire drawing process of the copper conductor of the liquid-cooled super-charging pile cable reasonably adjusts the pay-off and take-up tension according to the material, wire diameter, twisting structure and other factors of the copper wire to avoid different pay-off tensions affecting: A. Twisting uniformity: If the pay-off tension is unstable, the pay-off speeds of each copper wire will be inconsistent, resulting in uneven twisting. B. Conductor deformation: Too much pay-off tension may cause the copper wire to be overstretched and deformed; too little tension may cause the copper wire to be loose and the twisting to be loose. C. Product quality: It will affect the roundness, tightness and other quality indicators of the conductor after twisting. Different take-up tensions will affect: A. Appearance quality: Too much take-up tension will cause the stranded wire to be overstretched, the wire diameter will become smaller, and there will be problems such as strand jumping and burrs; too little take-up tension may cause the stranded wire to be loose and the wire arrangement to be uneven. B. Electrical performance: The take-up tension will affect the electrical properties of the stranded wire, such as resistance and inductance. Too much take-up tension may cause the copper wire to deform, resulting in increased resistance; too little take-up tension may make the structure of the stranded conductor unstable, affecting performance such as inductance.

[0029] 4. The wire drawing process of the copper conductor of the liquid-cooled super charging pile cable increases the appropriate amount of antioxidant, uses copper sulfate, which is usually used to form a protective oxide film to prevent oxidation of copper materials, uses ethylenediamine, which is often used as a corrosion inhibitor to slow down the corrosion rate of copper, and uses copper phosphate, which can be used as a rust inhibitor to form a protective oxide film. Preservatives and surfactants are used to improve the adhesion and corrosion resistance of the coating, and form a protective film on the surface of the copper wire to isolate the air and reduce the oxidation of the copper wire. At the same time, the antioxidant can also reduce the friction on the surface of the copper wire, reduce wear, improve wire drawing efficiency and product quality, and avoid friction between the copper wire and components such as molds and guide wheels during the copper wire drawing production process, which causes the surface temperature of the copper wire to rise and easily cause oxidation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings. Among them:

[0031] Figure 1 It is a tabular view of the copper wire quality parameters of the copper wires with different lengths of the present invention at the same wire drawing speed.

[0032] Figure 2 It is a view of the copper wire mass fraction parameters of the 1.8 mm long copper wire of the present invention under the concentration, temperature and pH value of the wire drawing oil respectively.

[0033] Figure 3 It is a view of the copper wire mass fraction parameters of the 0.20 mm long copper wire of the present invention under the concentration, temperature and pH value of the wire drawing oil respectively. Specific Embodiments

[0034] The following will combine the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0035] Embodiment 1:

[0036] A wire drawing process for the copper conductor of a liquid-cooled ultra-fast charging pile cable includes a copper wire drawing process. The copper wire drawing process specifically includes a wire drawing speed control process, and the control of the concentration, temperature and pH value of the wire drawing oil. The specific method steps are as follows:

[0037] Step 1: Use a wire drawing machine set to draw the copper conductor material into a single wire. Take the copper conductor material as the wire feeding, and draw it into a copper single wire through a wire drawing machine set with a round core. The diameter of the copper single wire is 0.20 mm, the speed of the wire drawing machine set is controlled at 22 m / s, and the wire drawing machine set can use a double-head wire drawing machine or a multi-head wire drawing machine;

[0038] Step 2: Use a stranding machine to arrange and strand several copper single wires obtained in Step 1 around a round core wire to form a wire blank, with the arc surfaces of the copper single wires facing the round core wire. Then, pre-twist the copper single wires. The copper single wires rotate 180° around their own wire shafts, and the pre-twist direction is opposite to the stranding rotation direction, ensuring that the small arc surfaces of the copper single wires face the core wire. Finally, all the copper single wires and the core wire converge at the forming bunching die and are stranded to form a copper wire blank. The stranding pitch diameter ratio of the outermost layer of strands is 8:20, and the stranding pitch diameter ratios of each layer of strands gradually increase from the outside to the inside, with the difference in stranding pitch diameter ratios between adjacent two layers being 3:8. For a copper conductor with a specification of 186 / 0.20AS (1*30 + 6*26) and a threading method of 2*6&8 + 2*7 / 1 + 6, the wire release tension of each bus bar during bunch stranding is 15N ± 5N, and the take-up tension is 30N ± 5N; during double stranding, the wire release tension of each bus bar per shaft is 35N ± 5N, and the take-up tension is 100N ± 5N;

[0039] Step 3: When using a double-head wire drawing machine for wire drawing, the concentration of the wire drawing oil is 15%; the temperature of the wire drawing oil is 35°C; the pH value of the wire drawing oil is 8.5; when using a multi-head wire drawing machine for wire drawing, the concentration of the wire drawing oil is 4%; the temperature of the wire drawing oil is 35°C; the pH value of the wire drawing oil is 8.5;

[0040] Step 4: Put the copper wire blank into an annealing furnace and heat it up to 300°C, with a holding time of 6h, and then let it stand and cool naturally to room temperature to become a semi-finished copper wire. Specifically, put the wire blank into a pre-heated annealing furnace and heat it up to 310°C, hold for 2h, then heat it up to 340°C and hold for 2h. Then, cool the wire blank that has completed heating at a cooling rate of 12°C per 0.1h until it reaches a temperature of 250°C and hold for 2h. Finally, take out the wire blank from the annealing furnace and let it stand and cool naturally to room temperature to obtain a semi-finished copper wire. By adding an appropriate dose of antioxidant to the original annealing liquid formulation, a protective film can be formed on the surface of the copper wire to isolate the air and reduce the oxidation of the copper wire. At the same time, the antioxidant can also reduce the friction on the surface of the copper wire, reduce wear, and improve the wire drawing efficiency and product quality. The antioxidant includes the following raw materials in parts by weight: 1% of sulfate compounds, 0.5% of organic amine compounds, 0.1% of phosphate compounds, and 0.1% of a mixture of preservatives and surfactants. The sulfate compounds are preferably copper sulfate, the organic amine compounds are preferably ethylenediamine, and the phosphate compounds are preferably copper phosphate. When using a double-head wire drawing machine, the daily antioxidant addition amount is 150 ml / day in winter (January - May and October - December) and 300 ml / day in summer (June - September); when using a multi-head wire drawing machine, the daily antioxidant addition amount is 400 ml;

[0041] Step 5: Wrap an inner insulating layer, a protective layer, and an insulating sheath around the semi-finished copper wire. After passing the electrical detection, it is a copper wire conductor.

[0042] Example 2:

[0043] A wire drawing process for the copper conductor of a liquid-cooled ultra-fast charging pile cable includes a copper wire drawing process. The copper wire drawing process specifically includes a wire drawing speed control process, and the control of the concentration, temperature, and pH value of the wire drawing oil. The specific method steps are as follows:

[0044] Step 1: Use a wire drawing machine set to draw the copper conductor material into single wires. The copper conductor material is used as the wire feedstock and is drawn into copper single wires through a wire drawing machine set with a round core. The diameter of the copper single wire is 1 mm, and the speed of the wire drawing machine set is controlled at 23 m / s. The wire drawing machine set can use a double-head wire drawing machine or a multi-head wire drawing machine;

[0045] Step 2: Use a stranding machine to arrange and strand several copper single wires obtained in Step 1 around a round core wire to form a wire blank. Make the arc surfaces of the copper single wires face the round core wire, and then pre-twist the copper single wires. The copper single wires rotate around their own wire shafts by an angle of 230°. The pre-twist direction is opposite to the stranding rotation direction to ensure that the small arc surfaces of the copper single wires face the core wire. Finally, the copper single wires and the core wire converge at the forming and bunching die and are stranded to form a copper wire blank. The stranding pitch diameter ratio of the outermost layer of strands is 8:20, and the stranding pitch diameter ratios of each layer of strands gradually increase from the outside to the inside. The difference in the stranding pitch diameter ratio between adjacent layers is 3:8; For a copper conductor with a specification of 186 / 0.20AS (1*30 + 6*26) and a threading method of 2*6&8 + 2*7 / 1 + 6, the wire release tension of each bus bar during bunch stranding is 15 N ± 5 N, and the take-up tension is 30 N ± 5 N; During double stranding, the wire release tension of each bus bar per shaft is 35 N ± 5 N, and the take-up tension is 100 N ± 5 N;

[0046] Step 3: When using a double-head wire drawing machine for wire drawing, the concentration of the wire drawing oil is 16%; the temperature of the wire drawing oil is 40 °C; the pH value of the wire drawing oil is 9; When using a multi-head wire drawing machine for wire drawing, the concentration of the wire drawing oil is 5%; the temperature of the wire drawing oil is 40 °C; the pH value of the wire drawing oil is 9;

[0047] Step 4: Put the copper wire blank into an annealing furnace, heat it up to 310°C, keep it warm for 7 hours, and then let it stand and cool naturally to room temperature to become a semi-finished copper wire. Specifically, put the wire blank into a preheated annealing furnace, heat it up to 315°C, keep it for 2.5 hours, then heat it up to 350°C and keep it for 2 hours. Then, let the wire blank with the temperature increase completed cool down at a rate of 15°C per 0.1 hour until the temperature reaches 260°C, and keep it warm for 2.5 hours. Finally, take out the wire blank from the annealing furnace and let it stand and cool naturally to room temperature to obtain a semi-finished copper wire. By adding an appropriate dose of antioxidant to the original annealing liquid formulation, a protective film can be formed on the surface of the copper wire to isolate the air and reduce the oxidation of the copper wire. At the same time, the antioxidant can also reduce the friction on the surface of the copper wire, reduce wear, improve the drawing efficiency and product quality. The antioxidant includes the following raw materials in parts by weight: 5% of sulfate compounds, 1% of organic amine compounds, 1% of phosphate compounds, 0.5% of a mixture of preservatives and surfactants. The sulfate compound is preferably copper sulfate, the organic amine compound is preferably ethylenediamine, and the phosphate compound is preferably copper phosphate. When using a double-head drawing machine, the daily antioxidant addition amount is 150 ml / day in winter (January - May and October - December) and 300 ml / day in summer (June - September). When using a multi-head drawing machine, the daily antioxidant addition amount is 400 ml.

[0048] Step 5: Wrap an inner insulating layer, a protective layer, and an insulating sheath around the semi-finished copper wire. After passing the electrical detection, it is a copper wire conductor.

[0049] Example 3:

[0050] A wire drawing process for a liquid-cooled ultra-fast charging pile cable copper conductor includes a copper wire drawing process. The copper wire drawing process specifically includes a wire drawing speed control process, and the control of the concentration, temperature, and pH value of the wire drawing oil. The specific method steps are as follows:

[0051] Step 1: Use a wire drawing machine set to draw the copper conductor material into a single wire. Take the copper conductor material as the wire feed and draw it into a single copper wire through a wire drawing machine set with a round core. The diameter of the single copper wire is 1.7 mm, the speed of the wire drawing machine set is controlled at 25 m / s, and the wire drawing machine set can be a double-head drawing machine or a multi-head drawing machine.

[0052] Step 2: Use a stranding machine to arrange and strand several copper single wires obtained in Step 1 around a round core wire to form a wire blank, with the arc surfaces of the copper single wires facing the round core wire. Then, pre-twist the copper single wires. The copper single wires rotate around their own wire shafts by an angle of 300°. The pre-twist direction is opposite to the stranding rotation direction to ensure that the small arc surfaces of the copper single wires face the core wire. Finally, the copper single wires and the core wire converge at the forming bunching die and are stranded to form a copper wire blank. The stranding pitch diameter ratio of the outermost layer of strands is 8:20, and the stranding pitch diameter ratios of each layer of strands gradually increase from the outside to the inside, with the difference in stranding pitch diameter ratios between adjacent two layers being 3:8. For a copper conductor with a specification of 186 / 0.20AS (1*30 + 6*26) and a threading method of 2*6&8 + 2*7 / 1 + 6, the wire release tension of each bus bar during bunch stranding is 15N ± 5N, and the take-up tension is 30N ± 5N; during double stranding, the wire release tension of each bus bar per shaft is 35N ± 5N, and the take-up tension is 100N ± 5N;

[0053] Step 3: When using a double-head wire drawing machine for wire drawing, the concentration of the wire drawing oil is 18%; the temperature of the wire drawing oil is 44°C; the pH value of the wire drawing oil is 9.3; when using a multi-head wire drawing machine for wire drawing, the concentration of the wire drawing oil is 7%; the temperature of the wire drawing oil is 44°C; the pH value of the wire drawing oil is 9.3;

[0054] Step 4: Place the copper wire blank in an annealing furnace and heat it up to 328°C, with a holding time of 9h, and then let it stand and cool naturally to room temperature to become a semi-finished copper wire. Specifically, place the wire blank in a pre-heated annealing furnace and heat it up to 328°C, hold for 2.8h, then heat up to 360°C and hold for 2h. Then, cool the wire blank that has completed the heating process at a cooling rate of 18°C per 0.1h until it reaches a temperature of 360°C and holds for 2.8h. Finally, take out the wire blank from the annealing furnace and let it stand and cool naturally to room temperature to obtain a semi-finished copper wire. By adding an appropriate dose of antioxidant to the original annealing liquid formulation, a protective film can be formed on the surface of the copper wire to isolate the air and reduce the oxidation of the copper wire. At the same time, the antioxidant can also reduce the friction on the surface of the copper wire, reduce wear, and improve the wire drawing efficiency and product quality. The antioxidant includes the following raw materials in parts by weight: 9% of sulfate compounds, 4% of organic amine compounds, 1.8% of phosphate compounds, and 0.8% of a mixture of preservatives and surfactants. The sulfate compound is preferably copper sulfate, the organic amine compound is preferably ethylenediamine, and the phosphate compound is preferably copper phosphate. When using a double-head wire drawing machine, the daily antioxidant addition amount is 150ml / day in winter (January - May and October - December) and 300ml / day in summer (June - September); when using a multi-head wire drawing machine, the daily antioxidant addition amount is 400ml;

[0055] Step 5: Wrap an inner insulating layer, a protective layer, and an insulating sheath around the semi-finished copper wire. After passing the electrical detection, it is a copper wire conductor.

[0056] Example 4:

[0057] A wire drawing process for the copper conductor of a liquid-cooled ultra-fast charging pile cable, including a copper wire drawing process, and the copper wire drawing process specifically includes a wire drawing speed control process, and the control of the concentration, temperature and pH value of the wire drawing oil. The specific method steps are as follows:

[0058] Step 1: Use a wire drawing machine set to draw the copper conductor material into single wires. The copper conductor material is used as the wire feed, and it is drawn into copper single wires through a wire drawing machine set with a round core. The diameter of the copper single wire is 1.8 mm, the speed of the wire drawing machine set is controlled at 26 m / s, and the wire drawing machine set can use a double-head wire drawing machine or a multi-head wire drawing machine;

[0059] Step 2: Use a stranding machine to arrange and strand several copper single wires obtained in Step 1 around the round core wire to form a wire blank. Make the arc surfaces of the copper single wires face the round core wire, and then pre-twist the copper single wires. The copper single wire rotates 360° around its own wire shaft, and the pre-twist direction is opposite to the stranding rotation direction, ensuring that the small arc surface of the copper single wire faces the core wire. Finally, the copper single wires and the core wire converge at the forming parallel wire die and are stranded to form a copper wire blank. The stranding pitch diameter ratio of the outermost layer of stranded wires is 8:20, and the stranding pitch diameter ratio of each layer of stranded wires gradually increases from the outside to the inside, and the difference in the stranding pitch diameter ratio between adjacent two layers is 3:8; For a copper conductor with a specification of 186 / 0.20AS (1*30 + 6*26) and a wire threading method of 2*6&8 + 2*7 / 1 + 6, the wire feeding tension of each bus bar during bunch stranding is 15 N ± 5 N, and the wire taking-up tension is 30 N ± 5 N; During double stranding, the wire feeding tension of each bus bar per shaft is 35 N ± 5 N, and the wire taking-up tension is 100 N ± 5 N;

[0060] Step 3: When using a double-head wire drawing machine for wire drawing, the concentration of the wire drawing oil is 19%; the temperature of the wire drawing oil is 45 °C; the pH value of the wire drawing oil is 9.5; when using a multi-head wire drawing machine for wire drawing, the concentration of the wire drawing oil is 8%; the temperature of the wire drawing oil is 45 °C; the pH value of the wire drawing oil is 9.5;

[0061] Step 4: Place the copper wire blank in an annealing furnace and heat it up to 330°C, with a holding time of 10 hours, and then let it stand and cool naturally to room temperature to become a semi-finished copper wire. Specifically, place the wire blank in a preheated annealing furnace and heat it up to 330°C, hold for 3 hours, then heat it up to 370°C and hold for 2 hours. Then, cool the wire blank that has completed the heating process at a cooling rate of 20°C per 0.1 hour until it reaches a temperature of 270°C and hold for 3 hours. Finally, take out the wire blank from the annealing furnace and let it stand and cool naturally to room temperature to obtain a semi-finished copper wire. By adding an appropriate dose of antioxidant to the original annealing liquid formulation, a protective film can be formed on the surface of the copper wire to isolate the air and reduce the oxidation of the copper wire. At the same time, the antioxidant can also reduce the friction on the surface of the copper wire, reduce wear, and improve the drawing efficiency and product quality. The antioxidant includes the following raw materials in parts by weight: 10% of sulfate compounds, 5% of organic amine compounds, 2% of phosphate compounds, and 1% of a mixture of preservatives and surfactants. The sulfate compound is preferably copper sulfate, the organic amine compound is preferably ethylenediamine, and the phosphate compound is preferably copper phosphate. When using a double-head drawing machine, the daily antioxidant addition amount is 150 ml / day in winter (January - May and October - December) and 300 ml / day in summer (June - September). When using a multi-head drawing machine, the daily antioxidant addition amount is 400 ml.

[0062] Step 5: Wrap an inner insulating layer, a protective layer, and an insulating sheath around the semi-finished copper wire. After passing the electrical property test, it becomes a copper wire conductor.

[0063] Experimental Example 1:

[0064] On the basis of Examples 1, 2, 3, and 4, adjust the drawing speed while keeping the rest the same. Referring to the methods of the above examples, compare the quality of the copper wire obtained in the above experimental examples with that of the examples, and the results are as Figure 1 shown. See Figure 1 It can be found that after adjusting the drawing speed, the best drawing speed for the double-head large drawing machine when producing 1.8 mm copper wire is 23 - 26 m / s, and the best drawing speed for the multi-head drawing machine when producing 0.20 mm copper wire needs to be controlled at 22 - 26 m / s.

[0065] Experimental Example 2:

[0066] On the basis of Examples 1, 2, and 3, change the values of the concentration, temperature, and pH value of the drawing oil while keeping the rest the same. Referring to the methods of the above examples, compare the quality of the copper wire obtained in the above experimental examples with that of the examples, and the results are as Figure 2 、 3 shown. See Figure 2 、 3It can be found that when changing the values of the concentration, temperature and pH value of the wire drawing oil, if a double-head wire drawing machine is used for wire drawing, the concentration of the wire drawing oil is 19%; the temperature of the wire drawing oil is 45°C; the pH value of the wire drawing oil is 9.5, which is the best; if a multi-head wire drawing machine is used for wire drawing, the concentration of the wire drawing oil is 8%; the temperature of the wire drawing oil is 45°C; the pH value of the wire drawing oil is 9.5, which is the best.

[0067] Judgment criterion: By comparing the copper wire conductors obtained in Examples 1, 2, 3, 4 and Experimental Examples 1 and 2, the quality of the wire drawing of the copper conductor can be evaluated.

[0068] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A wire drawing process for a liquid-cooled supercharging pile cable copper conductor, comprising a copper wire drawing process, wherein the copper wire drawing process specifically comprises a wire drawing speed control process, and controls the concentration, temperature and pH value of the wire drawing oil, and is characterized in that: The specific steps include the following: Step 1: Use a wire drawing unit to draw a single wire from the copper conductor material, use the copper conductor material as the wire to pay off the wire, and draw it into a copper single wire through a wire drawing unit that draws a round core; use a double-head wire drawing machine for wire drawing, wherein the wire drawing oil concentration is 15-19%; the wire drawing oil temperature is 35-45°C; the wire drawing oil pH value is 8.5-9.5; Wherein, the diameter of the copper single wire is 0.20 mm, the speed of the wire drawing unit is controlled at 22 m / s, and the wire drawing unit adopts a double-head wire drawing machine; or, the diameter of the copper single wire is 1 mm, the speed of the wire drawing unit is controlled at 23 m / s, and the wire drawing unit adopts a double-head wire drawing machine; or, the diameter of the copper single wire is 1.7 mm, the speed of the wire drawing unit is controlled at 25 m / s, and the wire drawing unit adopts a double-head wire drawing machine; or, the diameter of the copper single wire is 1.8 mm, the speed of the wire drawing unit is controlled at 26 m / s, and the wire drawing unit adopts a double-head wire drawing machine; Step 2: Arrange the several copper single wires obtained in step 1 around the round core wire and twist them into a conductor blank by a twisting machine, so that the arc surface of each copper single wire faces the round core wire, and then pre-twist the copper single wire, rotate the copper single wire around its own wire axis, and ensure that the small arc surface of the copper single wire faces the core wire. Finally, each copper single wire and the core wire are combined at a forming and twisting die, and twisted to form a copper conductor blank; Step 3, placing the copper wire blank in an annealing furnace and heating it to 300-330°C for 6-10 hours, and then standing and naturally cooling it to room temperature to become a copper wire semi-finished product, wherein an antioxidant is added to the annealing solution, and the antioxidant comprises the following raw materials in weight proportions: 1%-10% of sulfate compounds, 0.5%-5% of organic amine compounds, 0.1%-2% of phosphate compounds, and 0.1%-1% of a mixture of a preservative and a surfactant; the sulfate compound is copper sulfate, the organic amine compound is ethylenediamine, and the phosphate compound is copper phosphate; Step 4: Wrap the inner insulation layer, protective layer and insulating sheath on the outside of the copper wire semi-finished product, and it will be a copper wire conductor if it passes the electrical test.

2. The wire drawing process of the copper conductor of the liquid-cooled supercharging pile cable according to claim 1 is characterized in that: The copper single wire rotates around its own wire axis at an angle of 180° to 360°, and the pre-twisting direction is opposite to the rotation direction of the stranded wire.

3. The wire drawing process of the copper conductor of the liquid-cooled supercharging pile cable according to claim 1 is characterized in that: In the step 2, the twisted pitch diameter ratio of the outermost layer of twisted wire is 8:20, the twisted pitch diameter ratio of each layer of twisted wire gradually increases from the outside to the inside, and the difference in twisted pitch diameter ratio between two adjacent layers is 3:

8.

4. The wire drawing process of the copper conductor of the liquid-cooled supercharging pile cable according to claim 1 is characterized in that: In the step 2, the copper conductor with a specification of 186 / 0.20AS (1*30+6*26) and a threading method of 2*6&8+2*7 / 1+6 is twisted with a pay-off tension of 15N±5N for each busbar and a take-up tension of 30N±5N; the pay-off tension of each busbar axis during re-twisting is 35N±5N, and the take-up tension is 100N±5N.

5. The wire drawing process of the copper conductor of the liquid-cooled supercharging pile cable according to claim 1, characterized in that: In the step 3, specifically, the conductor blank is placed in a preheated annealing furnace and heated to 310-330° C., maintained for 2-3 hours, then heated to 340-370° C., maintained for 2 hours, and then the conductor blank that has been heated is cooled to a temperature of 250-270° C. at a cooling rate of 12-20° C. per 0.1 hour, and maintained for 2-3 hours. Finally, the conductor blank is taken out of the annealing furnace and allowed to stand and naturally cool to room temperature to obtain a copper conductor semi-finished product.

6. The wire drawing process of the copper conductor of the liquid-cooled supercharging pile cable according to claim 1, characterized in that: In the step three, by adding a suitable amount of antioxidant to the original annealing solution, a protective film is formed on the surface of the copper wire to isolate the air and reduce the oxidation of the copper wire; at the same time, the antioxidant also reduces the friction on the surface of the copper wire, reduces wear, and improves wire drawing efficiency and product quality.

7. The wire drawing process of the copper conductor of the liquid-cooled supercharging pile cable according to claim 6 is characterized in that: If a double-head wire drawing machine is used, the daily amount of antioxidant added is: 150ml / day from January to May, 150ml / day from October to December, and 300ml / day from June to September; if a multi-head wire drawing machine is used, the daily amount of antioxidant added is 400ml / day.

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