Ultrafine alloy wire for automobile and preparation method thereof

Abstract

The invention relates to the technical field of automobile wires, in particular to a superfine alloy wire for an automobile and a preparation method thereof, and the method comprises the steps: obtaining a plurality of aluminum wires and steel core wires; electroplating a copper layer on the steel core wire to obtain a copper-clad steel wire, and determining whether the drawing process of the copper-clad steel wire is stable or not based on the fluctuation of the wire diameter; whether steel component permeation exists in the copper layer or not is determined based on the copper content or the iron content of the scrapes; adjusting the current density based on the ratio or determining whether the electroplating process is qualified or not according to the coating distribution uniformity of the copper-clad steel wire after wire drawing; a plurality of groups of copper-clad aluminum wires are twisted through a wire bunching machine and wrap the copper-clad steel wires in a surrounding manner to form a circular conductor structure; determining whether the twisting coating process is qualified based on the composite morphology index so as to adjust the production speed or the tensile tension according to the relative difference; and the circular conductor structure is coated with polyvinyl chloride, crosslinked polyethylene and fluoroplastic through an extruding machine to obtain an insulating layer. According to the invention, the structural stability of the superfine alloy wire for the automobile is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of automotive wires, and particularly to an ultra-fine alloy wire for automobiles and a preparation method thereof. Background Art

[0002] With the rapid development of the automotive industry, especially the popularization of electric vehicles and hybrid vehicles, the requirements for wires are increasing day by day. In automotive circuits, ultra-fine alloy wires have become an ideal choice to replace traditional wires due to their excellent electrical conductivity, high strength, and good corrosion resistance. However, there are many challenges in the preparation process of ultra-fine alloy wires, such as the stability of the wire drawing process, the quality of the electroplated layer, the uniformity of stranding and coating, etc. Especially in the wire drawing and electroplating processes, due to the limitations of material properties and process parameters, it is very difficult to achieve stable wire drawing and high-quality electroplated layers, which not only affects the performance of the wires, but also increases the production cost and the difficulty of quality control.

[0003] Chinese Patent Application Publication No.: CN118866475A discloses a preparation process of a high-voltage-resistant cable for new energy vehicles. This process includes the following steps: Step 1, raw material preparation: placing the required metal conductors on the pay-off reel; Step 2, wire drawing: starting the wire drawing machine, gradually drawing the thick metal conductor through the die to reach the required wire diameter specification; Step 3, stranding; Step 4, insulation extrusion; Step 5, cabling; Step 6, take-up. The stranded cable is positioned and guided by the traction assembly, so that multiple wire cores gather inside the traction assembly to facilitate cabling; at the same time, the traction assembly and the take-up assembly rotate in opposite directions, and the surface of the cabled cable is rubbed by the traction assembly, which can remove burrs, protrusions or uneven parts on the surface of the cable, and the thickness of the friction can also be adjusted, so as to be applicable to cables of different materials. However, the following problems exist in the prior art: In the prior art, during the wire drawing process, there is a lack of monitoring and precise control of the wire drawing process, resulting in low stability of the wire drawing process, and thus the problem of low structural stability of the ultra-fine alloy wire for automobiles. Summary of the Invention

[0004] Therefore, the present invention provides an ultra-fine alloy wire for automobiles and a preparation method thereof to overcome the problems in the prior art that during the wire drawing process, there is a lack of monitoring and precise control of the wire drawing process, resulting in low stability of the wire drawing process, and thus the problem of low structural stability of the ultra-fine alloy wire for automobiles.

[0005] To achieve the above object, the present invention provides a preparation method of an ultra-fine alloy wire for automobiles, including: Obtaining a plurality of aluminum wires and steel core wires; Electroplating a copper layer on the steel core wire to obtain a copper-clad steel wire, drawing the copper-clad steel wire through a wire drawing machine, and determining whether the wire drawing process of the copper-clad steel wire is stable based on the wire diameter fluctuation of the copper-clad steel wire; Collect the surface scrapings of the copper-clad steel wire when the wire drawing process is unstable, and determine whether there is steel component penetration inside the copper layer based on the copper content or iron content of the scrapings; Under the condition of determining the existence of steel component penetration, adjust the current density based on the ratio of the copper content to the preset copper content or determine whether the electroplating process is qualified according to the coating distribution uniformity of the copper-clad steel wire after wire drawing; Electroplate a copper layer on the aluminum wire to obtain a copper-clad aluminum wire, and twist and surround multiple groups of the copper-clad aluminum wires outside the copper-clad steel wire with stable wire drawing process through a bunching machine to form a circular conductor structure; Determine whether the stranding and coating process is qualified based on the composite morphology index of the circular conductor structure, and adjust the production speed or drawing tension according to the relative difference between the composite morphology index and the preset composite morphology index; Coat polyvinyl chloride, cross-linked polyethylene, and fluoroplastics outside the circular conductor structure through an extruder to obtain an insulating layer.

[0006] Further, determine that the wire drawing process of the copper-clad steel wire is unstable based on the comparison result that the wire diameter fluctuation of the copper-clad steel wire during wire drawing is greater than the preset wire diameter fluctuation, and determine that there is steel component penetration inside the copper layer according to the comparison result that the copper content of the scrapings under the first layer of detection method is greater than or equal to the preset copper content; Wherein, the first layer of detection method is to scrape the surface copper layer to a depth of 50% of the copper layer thickness from several sampling points, collect the scrapings of each sampling point respectively and detect whether they contain steel.

[0007] Further, under the condition of determining that there is steel component penetration inside the copper layer, the process of adjusting the current density includes: Divide the copper content by the preset copper content; Set several adjustment coefficients corresponding to the corresponding ratio; Increase the electroplating current density based on several of the adjustment coefficients; Set the corresponding relationship between the corresponding ratio and the increased electroplating current density to adjust the current density.

[0008] Further, determine that the wire drawing process of the copper-clad steel wire is unstable based on the comparison result that the wire diameter fluctuation of the copper-clad steel wire during wire drawing is greater than the preset wire diameter fluctuation, and determine that there is steel component penetration inside the copper layer according to the comparison result that the iron content of the scrapings under the second layer of detection method is greater than or equal to the preset iron content; Wherein, the second layer of detection method is to scrape the copper layer from several sampling points until the steel core wire is just exposed, collect the scrapings of each sampling point respectively and detect whether they contain steel.

[0009] Further, it is determined that the electroplating process is unqualified based on the comparison result that the coating distribution uniformity of the copper-clad steel wire after wire drawing is less than or equal to a preset coating distribution uniformity.

[0010] Further, under the condition of determining that the electroplating process is unqualified, the process of adjusting the electroplating temperature or stirring speed of the electroplating process includes: Taking the absolute value after subtracting the coating distribution uniformity from the preset coating distribution uniformity; Based on the comparison result that the absolute difference is less than or equal to a preset absolute difference, it is determined to increase the stirring speed with a preset stirring speed adjustment coefficient; Based on the comparison result that the absolute difference is greater than the preset absolute difference, it is determined to increase the electroplating temperature with a preset electroplating temperature adjustment coefficient.

[0011] Further, it is determined that the electroplating process is qualified but the wire drawing process is unqualified based on the comparison result that the coating distribution uniformity of the copper-clad steel wire after wire drawing is less than or equal to a preset coating distribution uniformity.

[0012] Further, under the condition of determining that the electroplating process is qualified but the wire drawing process is unqualified, the process of adjusting the parameters of the wire drawing machine includes: Subtracting the coating distribution uniformity from the preset coating distribution uniformity; Based on the comparison result that the difference is less than or equal to a preset difference, it is determined to reduce the drawing speed of the wire drawing machine with a first preset drawing speed adjustment coefficient; Based on the comparison result that the difference is greater than the preset difference, it is determined to reduce the drawing speed of the wire drawing machine with a second preset drawing speed adjustment coefficient.

[0013] Further, based on the comparison result that the composite morphology index of the circular conductor structure is less than or equal to the composite morphology index threshold, it is determined to be less than or equal to the composite morphology index threshold, and according to the comparison result of the relative difference between the composite morphology index threshold and the composite morphology index and a preset relative difference, it is determined to increase the production speed of the bunching machine with a preset production speed adjustment coefficient or reduce the drawing tension of the wire drawing machine with a preset drawing tension adjustment coefficient.

[0014] On the other hand, the present invention also provides an extremely fine alloy wire for automobiles, including: A copper-clad steel wire, which is used as a conductor to transmit electric energy; A copper-clad aluminum wire, which is coated outside the copper-clad steel wire to protect the copper-clad steel wire; An insulating layer, which is coated outside the copper-clad aluminum wire to provide electrical isolation for the alloy wire.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows. By monitoring the stability of the copper-clad steel wire drawing process, the present invention can timely detect and solve the wire diameter fluctuation problem caused by unstable wire drawing, ensuring the quality of the copper-clad steel wire. By collecting the surface scraps of the copper-clad steel wire during the unstable wire drawing process and analyzing whether there is steel component penetration inside the copper layer, the purity and performance of the material are guaranteed, providing a more reliable conductive basis for the wire. After electroplating a copper layer on an aluminum wire to obtain a copper-clad aluminum wire, it is stranded and wrapped around the outside of the copper-clad steel wire with stable wire drawing to form a circular conductor structure. By monitoring the composite morphology index of the circular conductor structure, the qualification of the stranding and wrapping process is accurately evaluated, and the production speed or drawing tension is adjusted according to the evaluation result to optimize the tightness and uniformity of the conductor structure, improving the mechanical strength of the wire and ensuring the stability of current transmission, thereby improving the structural stability of the ultra-fine alloy wire for automobiles.

[0016] Furthermore, the present invention determines the wire drawing stability by monitoring the wire diameter fluctuation during the copper-clad steel wire drawing process; when it is unstable, scraps are collected to detect the steel component penetration inside the copper layer; according to the detection result, the electroplating current density is adjusted, ensuring the wire drawing quality of the copper-clad steel wire and the purity of the copper layer, avoiding the performance degradation caused by the steel component penetration. At the same time, according to the detection result of the scraps, the electroplating current density is adjusted to optimize the electroplating process, improving the conductive performance and structural stability of the wire.

[0017] Furthermore, the present invention determines the steel component penetration situation inside the copper layer by detecting the iron content of the scraps in the second layer, evaluates the electroplating process based on the uniformity of the coating distribution, and adjusts the electroplating temperature or stirring speed when it is unqualified, accurately judging the steel component penetration situation inside the copper layer, avoiding the wire performance degradation caused by the steel component penetration, evaluating the qualification of the electroplating process based on the uniformity of the coating distribution, ensuring the quality and uniformity of the electroplating layer, providing a stable conductive performance for the wire. When the electroplating process is unqualified, the electroplating temperature or stirring speed is adjusted according to the deviation of the coating distribution uniformity, improving the quality of the electroplating layer and the overall performance of the wire, guaranteeing the wire quality and performance, and improving the structural stability of the wire.

[0018] Furthermore, when the electroplating process is qualified but the wire drawing process is unqualified, the present invention adjusts the drawing speed of the wire drawing machine according to the difference between the coating distribution uniformity and the preset value, ensuring the stability and controllability of the wire drawing process, avoiding the wire quality problems caused by improper wire drawing speed, and improving the production efficiency and stability of the wire.

[0019] Furthermore, in the present invention, a bunching machine is used to twist and wrap the copper-clad aluminum wire around the outside of a stable copper-clad steel wire to form a circular conductor structure. The stranding and wrapping process is evaluated based on the composite morphology index. When it is unqualified, the production speed or the drawing tension is adjusted to ensure the stability and quality of the circular conductor structure. The composite morphology index, as an evaluation index, comprehensively reflects the morphological characteristics of the conductor structure, thereby accurately judging the qualification of the stranding and wrapping process, optimizing the tightness and uniformity of the conductor structure, and improving the stability of current transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a flowchart of a method for preparing an ultra-fine alloy wire for an automobile according to an embodiment of the present invention; Figure 2 is a flowchart of determining whether the wire drawing process of the copper-clad steel wire is stable according to an embodiment of the present invention; Figure 3 is a flowchart of determining whether the electroplating process is qualified according to an embodiment of the present invention; Figure 4 is a structural diagram of an ultra-fine alloy wire for an automobile according to an embodiment of the present invention; In the figure, 1 is a copper-clad steel wire; 2 is a copper-clad aluminum wire; 3 is an insulating layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] In order to make the objectives and advantages of the present invention clearer, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and do not limit the protection scope of the present invention.

[0023] It should be noted that the data in this embodiment are all obtained through comprehensive analysis and evaluation of the historical test data and the corresponding historical test results in the three months before this test by the present invention. Those skilled in the art can understand that the determination method of the present invention for a single above-mentioned parameter can be to select the value with the highest proportion according to the data distribution as the preset standard parameter, use weighted summation to obtain the value as the preset standard parameter, substitute each historical data into a specific formula and use the value obtained by this formula as the preset standard parameter or other selection methods, as long as it satisfies that the present invention can clearly define different specific situations in the single-item determination process through the obtained values.

[0024] Please refer to Figure 1 shown, which is a flowchart of a method for preparing an ultra-fine alloy wire for an automobile according to an embodiment of the present invention.

[0025] An embodiment of the present invention provides a method for preparing an ultra-fine alloy wire for an automobile, including: Step S1, obtaining a plurality of aluminum wires and a steel core wire; Step S2, electroplating a copper layer on the steel core wire to obtain a copper-clad steel wire, drawing the copper-clad steel wire through a wire drawing machine, and determining whether the wire drawing process of the copper-clad steel wire is stable based on the wire diameter fluctuation of the copper-clad steel wire; Step S3, collecting the surface scraps of the copper-clad steel wire when the wire drawing process is unstable, and determining whether there is steel component penetration inside the copper layer based on the copper content or iron content of the scraps; Step S4, under the condition of determining that there is steel component penetration, adjusting the current density based on the ratio of the copper content to the preset copper content or determining whether the electroplating process is qualified according to the coating distribution uniformity of the copper-clad steel wire after wire drawing; Step S5, electroplating a copper layer on the aluminum wire to obtain a copper-clad aluminum wire, and stranding and winding multiple groups of the copper-clad aluminum wires around the copper-clad steel wire with a stable wire drawing process to form a circular conductor structure; Step S6, determining whether the stranding and winding process is qualified based on the composite morphology index of the circular conductor structure, and adjusting the production speed or the drawing tension according to the relative difference between the composite morphology index and the preset composite morphology index; Step S7, coating polyvinyl chloride, cross-linked polyethylene, and fluoroplastics on the outside of the circular conductor structure through an extruder to obtain an insulating layer.

[0026] During the implementation process, the thickness of the electroplated copper layer is 0.2 mm, the copper content of the copper layer is 99.95%, the volume ratio of copper in the copper-clad steel wire is 40%-60%, preferably 50%, the volume ratio of copper in the copper-clad aluminum wire is 20%-40%, preferably 30%. The value range and the preferred value of the volume ratio of copper can be determined according to the actual situation, and no specific limitation is made here and will not be elaborated further.

[0027] Specifically, by monitoring the stability of the wire drawing process of the copper-clad steel wire, the present invention can timely detect and solve the problem of wire diameter fluctuation caused by unstable wire drawing, ensure the quality of the copper-clad steel wire, and by collecting the surface scraps of the copper-clad steel wire when the wire drawing process is unstable, analyze whether there is steel component penetration inside the copper layer, which guarantees the purity and performance of the material, provides a more reliable conductive foundation for the wire. After electroplating a copper layer on the aluminum wire to obtain a copper-clad aluminum wire, it is stranded and wound around the copper-clad steel wire with a stable wire drawing process to form a circular conductor structure. By monitoring the composite morphology index of the circular conductor structure, accurately evaluating the qualification of the stranding and winding process, and adjusting the production speed or the drawing tension according to the evaluation result, the tightness and uniformity of the conductor structure are optimized, the mechanical strength of the wire is improved, and the stability of current transmission is ensured, thereby improving the structural stability of the ultra-fine alloy wire for an automobile.

[0028] Specifically, a copper layer is electroplated on the steel core wire to obtain a copper-clad steel wire, and the copper-clad steel wire is drawn by a wire drawing machine.

[0029] During the implementation process, the current density range in the electroplating process is 10 A / dm² - 15 A / dm², and the preferred value is 12 A / dm². The temperature range of the electroplating solution is 45°C - 55°C, and the preferred value is 50°C. The stirring speed range of the electroplating bath is 280 rpm - 320 rpm, and the preferred value is 300 rpm. The value of the current density is obtained by taking the average of the current densities when several cables were qualified in the past. The temperature of the electroplating solution is obtained by taking the average of the electroplating solution temperatures when several cables were qualified in the past. The value range and preferred value of the stirring speed can be determined according to the actual situation, and no specific limitation is made here and will not be elaborated further.

[0030] During the implementation process, the drawing speed range of the wire drawing machine is 5 m / min - 15 m / min, and the preferred value is 10 m / min. The tensile tension range is 80 N - 100 N, and the preferred value is 90 N. During the implementation, the value range and preferred value of the drawing speed and tensile tension can be determined according to the actual situation. The wire drawing machine is one of a straight-through wire drawing machine or an inverted wire drawing machine, and no specific limitation is made here and will not be elaborated further.

[0031] Please refer to Figure 2 as shown, which is a flowchart for determining whether the copper-clad steel wire drawing process is stable in an embodiment of the present invention.

[0032] Specifically, in the embodiment of the present invention, under the condition of determining the drawing of the copper-clad steel wire, it is determined whether the copper-clad steel wire drawing process is stable according to the comparison result between the wire diameter fluctuation of the copper-clad steel wire during the drawing process and the preset wire diameter fluctuation; When the wire diameter fluctuation is less than or equal to the preset wire diameter fluctuation, it is determined that the copper-clad steel wire drawing process is stable; When the wire diameter fluctuation is greater than the preset wire diameter fluctuation, it is determined that the copper-clad steel wire drawing process is unstable.

[0033] In the embodiment of the present invention, the preset wire diameter fluctuation value is 0.01 mm, and the preset wire diameter fluctuation is obtained by taking the maximum value of the wire diameter fluctuations when several copper-clad steel wire drawing processes were stable in the past. However, the above value is not limited to this, and those skilled in the art can also adjust this value according to actual needs.

[0034] During the implementation process, a laser diameter gauge is used to take several detection points on the copper-clad steel wire, and the wire diameter fluctuation is the ratio of the sum of the absolute values of the vertical offset distances of the wire diameters of all detection points relative to the horizontal plane to the number of detection points.

[0035] Specifically, under the condition that it is determined that the wire drawing process of the copper-clad steel wire is unstable, a number of sampling points are selected on the surface of the drawn copper-clad steel at a preset interval of 2 cm, and the area of the sampling points ranges from 0.5 mm 2 -2 mm 2 , preferably 1 mm 2 . For the first layer detection method, the surface copper layer of the sampling point is scraped to a depth of 50% of the copper layer thickness, and the scrapings of each sampling point are collected and detected for the presence of steel; for the second layer detection method, the copper layer of the sampling point is scraped off until the steel core wire is just exposed, and the scrapings of each sampling point are collected and detected for the presence of steel, that is, the iron content is detected. Among them, the detection means is EDX detection or chemical titration method, which is not specifically limited here and will not be elaborated further.

[0036] Specifically, under the condition of determining the first layer detection method, it is determined whether there is steel component penetration inside the copper layer according to the comparison result between the copper content of the scrapings and the preset copper content; When the copper content is less than the preset copper content, it is determined that there is steel component penetration inside the copper layer; When the copper content is greater than or equal to the preset copper content, it is determined that there is steel component penetration inside the copper layer.

[0037] In the embodiment of the present invention, the preset copper content is 99.95%, and the preset copper content is the copper content of the copper layer, but the above value is not limited to this, and those skilled in the art can also adjust this value according to actual needs.

[0038] Specifically, under the condition that it is determined by the first layer detection method that there is steel component penetration inside the copper layer, the adjustment of the current density is determined according to the comparison result between the ratio of the copper content to the preset copper content and the preset ratio; When the ratio is less than or equal to the preset ratio, it is determined to increase the current density of electroplating to the corresponding value with the first preset current density adjustment coefficient of 1.05; When the ratio is greater than the preset ratio, it is determined to increase the current density of electroplating to the corresponding value with the second preset current density adjustment coefficient of 1.09; The ratio is the ratio of the copper content to the preset copper content, In the embodiment of the present invention, the preset ratio is 0.95, but the above value is not limited to this, and those skilled in the art can also adjust this value according to actual needs.

[0039] In the embodiments of the present invention, the increased current density is the product of a preset current density adjustment coefficient and the current density. The preset current density adjustment coefficient includes a first preset current density adjustment coefficient with a value of 1.05 and a second preset current density adjustment coefficient with a value of 1.09. To ensure that the adjusted current density meets the actual requirements and the adjustment range is not too large, the adjustment coefficient is correspondingly set to control the adjustment range.

[0040] Specifically, the present invention monitors the wire diameter fluctuation during the drawing process of the copper-clad steel wire to determine the drawing stability. When it is unstable, it collects chips to detect the penetration of the steel component inside the copper layer. According to the detection results, it adjusts the electroplating current density, which ensures the drawing quality of the copper-clad steel wire and the purity of the copper layer, avoids the performance degradation caused by the penetration of the steel component. At the same time, adjusting the electroplating current density according to the chip detection results optimizes the electroplating process and improves the electrical conductivity and structural stability of the wire.

[0041] Specifically, in the embodiments of the present invention, under the condition of determining the second-layer detection, it determines whether there is penetration of the steel component inside the copper layer according to the comparison result between the iron content of the chip and the preset iron content. When the iron content is less than or equal to the preset iron content, it is determined that there is no penetration of the steel component inside the copper layer. When the iron content is greater than or equal to the preset iron content, it is determined that there is penetration of the steel component inside the copper layer.

[0042] In the embodiments of the present invention, the preset iron content is 0.05%. The iron content is obtained by taking the average value of the iron contents in a number of historical cases where it is determined that there is penetration of the steel component inside the copper layer. However, the above value is not limited to this, and those skilled in the art can also adjust this value according to actual needs.

[0043] Please refer to Figure 3 as shown, which is the flowchart for the embodiments of the present invention to determine whether the electroplating process is qualified.

[0044] Specifically, in the embodiments of the present invention, under the condition of determining the second-layer detection and the penetration of the steel component inside the copper layer, it determines whether the electroplating process is qualified according to the comparison result between the coating distribution uniformity of the copper-clad steel wire after drawing and the preset coating distribution uniformity. When the coating distribution uniformity is less than or equal to the preset coating distribution uniformity, it is determined that the electroplating process is unqualified. When the coating distribution uniformity is greater than the preset coating distribution uniformity, it is determined that the electroplating process is qualified but the drawing process is unqualified.

[0045] In the embodiments of the present invention, the preset coating distribution uniformity value is 0.93. The preset coating distribution uniformity is obtained by taking the average value of the coating distribution uniformities qualified in a number of historical electroplating processes. However, the above value is not limited to this, and those skilled in the art can also adjust this value according to actual needs.

[0046] During the implementation process, the coating distribution uniformity is the standard deviation of the scraping thickness and the copper layer thickness at a number of sampling points.

[0047] Specifically, in the embodiments of the present invention, under the condition that the electroplating process is determined to be unqualified, the electroplating temperature or the stirring speed is determined according to the comparison result of the absolute difference between the coating distribution uniformity and the preset coating distribution uniformity and the preset absolute difference; When the absolute difference is less than or equal to the preset absolute difference, it is determined to increase the stirring speed to the corresponding value with a preset stirring speed adjustment coefficient of 1.15; When the absolute difference is greater than the preset absolute difference, it is determined to increase the electroplating temperature to the corresponding value with a preset electroplating temperature adjustment coefficient of 1.12; The absolute difference is the absolute difference between the coating distribution uniformity and the preset coating distribution uniformity.

[0048] In the embodiments of the present invention, the preset absolute difference value is 0.25. However, the above value is not limited to this, and those skilled in the art can also adjust this value according to actual needs.

[0049] In the embodiments of the present invention, the increased stirring speed is the product of the stirring speed and the preset stirring speed adjustment coefficient, and the preset stirring speed adjustment coefficient value is 1.15; the increased electroplating temperature is the product of the electroplating temperature and the preset electroplating temperature adjustment coefficient, and the preset electroplating temperature adjustment coefficient value is 1.12. To ensure that the adjusted stirring speed and electroplating temperature meet the actual requirements, the adjustment range should not be too large, so the adjustment coefficient is correspondingly set to control the adjustment range.

[0050] Specifically, the present invention determines the penetration of the steel component in the copper layer by detecting the iron content in the second-layer scraping, evaluates the electroplating process based on the coating distribution uniformity, adjusts the electroplating temperature or the stirring speed when it is unqualified, accurately judges the penetration of the steel component inside the copper layer, avoids the decline of the wire performance caused by the penetration of the steel component, evaluates the qualification of the electroplating process based on the coating distribution uniformity, ensures the quality and uniformity of the electroplating layer, provides stable electrical conductivity for the wire, and when the electroplating process is unqualified, adjusts the electroplating temperature or the stirring speed according to the deviation of the coating distribution uniformity, improves the quality of the electroplating layer and the overall performance of the wire, guarantees the quality and performance of the wire, and improves the structural stability of the wire.

[0051] Specifically, under the condition that the electroplating process is qualified but the wire drawing process is unqualified in the embodiments of the present invention, the parameters of the wire drawing machine are determined according to the comparison result between the difference between the coating distribution uniformity and the preset coating distribution uniformity and a preset difference value; When the difference value is less than or equal to the preset difference value, it is determined that the drawing speed of the wire drawing machine is reduced to a corresponding value with a first preset drawing speed adjustment coefficient of 0.96; When the difference value is greater than the preset difference value, it is determined that the drawing speed of the wire drawing machine is reduced to a corresponding value with a second preset drawing speed adjustment coefficient of 0.93; The difference value is the difference between the coating distribution uniformity and the preset coating distribution uniformity.

[0052] In the embodiments of the present invention, the preset difference value is taken as 0.05, but the above value is not limited to this, and those skilled in the art can also adjust this value according to actual needs.

[0053] In the embodiments of the present invention, the reduced drawing speed is the product of the preset drawing speed adjustment coefficient. The preset drawing speed adjustment coefficient includes a first preset drawing speed adjustment coefficient with a value of 0.96 and a second preset drawing speed adjustment coefficient with a value of 0.93. To ensure that the adjusted drawing speed meets the actual requirements and the adjustment range should not be too large, the adjustment coefficient is correspondingly set to control the adjustment range.

[0054] Specifically, in the present invention, when the electroplating process is qualified but the wire drawing process is unqualified, the drawing speed of the wire drawing machine is adjusted according to the difference between the coating distribution uniformity and the preset value, ensuring the stability and controllability of the wire drawing process, avoiding wire quality problems caused by improper wire drawing speed, and improving the production efficiency and stability of the wire.

[0055] Specifically, a copper layer is electroplated on the aluminum wire to obtain a copper-clad aluminum wire, and multiple groups of the copper-clad aluminum wires are stranded by a bunching machine and wound around the outside of the copper-clad steel wire with a stable wire drawing process to form a circular conductor structure.

[0056] In the embodiments of the present invention, the host rotation speed range of the bunching machine is 100 rpm - 150 rpm, preferably 120 rpm, and the production speed range is 100 m / min - 120 m / min, preferably 110 m / min. In practice, the value range and preferred value of the host rotation speed and production speed can be determined according to the actual situation. The type of the bunching machine is one of a single-wire bunching machine or a multi-filament bunching machine, which is not specifically limited here and will not be elaborated further.

[0057] Specifically, under the condition that a circular conductor structure is determined to be formed in the embodiments of the present invention, it is determined whether the stranding and winding process is qualified according to the comparison result between the composite morphology index of the circular conductor structure and the composite morphology index threshold; When the composite morphology index is less than or equal to the composite morphology index threshold, it is determined that the stranding and covering process is unqualified; When the composite morphology index is greater than the composite morphology index threshold, it is determined that the stranding and covering process is qualified.

[0058] In the embodiment of the present invention, the value of the composite morphology index threshold is 0.85, but the above value is not limited thereto, and those skilled in the art can also adjust the value according to actual needs.

[0059] In the implementation process, the composite morphology index is the product of the cross-sectional ellipticity of the round conductor structure and the proportion of the stranding gap area, and both the cross-sectional area ellipticity and the stranding gap area are obtained by a laser diameter gauge.

[0060] Specifically, in the embodiment of the present invention, under the condition that it is determined that the stranding and covering process is unqualified, the production speed or the drawing tension is determined according to the comparison result between the relative difference between the composite morphology index threshold and the composite morphology index and a preset relative difference; When the relative difference is less than or equal to the preset relative difference, it is determined that the production speed of the bunching machine is increased to the corresponding value with a preset production speed adjustment coefficient of 1.06; When the relative difference is greater than the preset relative difference, it is determined that the drawing tension of the wire drawing machine is reduced to the corresponding value with a preset drawing tension adjustment coefficient of 0.94 The relative difference is the relative difference between the composite morphology index threshold and the composite morphology index.

[0061] In the embodiment of the present invention, the value of the preset relative difference is 0.1, but the above value is not limited thereto, and those skilled in the art can also adjust the value according to actual needs.

[0062] In the embodiment of the present invention, the increased production speed is the product of the production speed and the preset production speed adjustment coefficient, and the value of the preset production speed adjustment coefficient is 1.06; the reduced drawing tension is the product of the drawing tension and the preset drawing tension adjustment coefficient, and the value of the preset drawing tension adjustment coefficient is 0.94. To ensure that the adjusted production speed and drawing tension meet the actual requirements, the adjustment range should not be too large, so the adjustment coefficient is correspondingly set to control the adjustment range.

[0063] Specifically, the present invention twists and covers the copper-clad aluminum wire on the outside of the stable copper-clad steel wire through a bunching machine to form a round conductor structure, evaluates the stranding and covering process based on the composite morphology index, and adjusts the production speed or the drawing tension when it is unqualified, ensuring the stability and quality of the round conductor structure. The composite morphology index, as an evaluation index, comprehensively reflects the morphological characteristics of the conductor structure, thus accurately judging the qualification of the stranding and covering process, optimizing the tightness and uniformity of the conductor structure, and improving the stability of current transmission.

[0064] Please refer to Figure 4 as shown, which is the structural diagram of the ultra-fine alloy wire for automobiles in the embodiment of the present invention.

[0065] The embodiment of the present invention also provides an ultra-fine alloy wire for automobiles, including: A copper-clad steel wire, which is used as a conductor to transmit electric energy; A copper-clad aluminum wire, which is coated outside the copper-clad steel wire to protect the copper-clad steel wire; An insulating layer, which is coated outside the copper-clad aluminum wire to provide electrical isolation for the alloy wire.

[0066] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present invention.

[0067] The above are only the preferred embodiments of the present invention and are not used to limit the present invention; for those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing an ultra-fine alloy wire for automobiles, characterized in that, Including: Obtaining a plurality of aluminum wires and steel core wires; Electroplating a copper layer on the steel core wire to obtain a copper-clad steel wire, drawing the copper-clad steel wire through a wire drawing machine, and determining whether the drawing process of the copper-clad steel wire is stable based on the wire diameter fluctuation of the copper-clad steel wire; Collecting the surface scrapings of the copper-clad steel wire when the drawing process is unstable, and determining whether there is steel component penetration inside the copper layer based on the copper content or iron content of the scrapings; Under the condition of determining that there is steel component penetration, adjusting the current density based on the ratio of the copper content to the preset copper content or determining whether the electroplating process is qualified according to the coating distribution uniformity of the copper-clad steel wire after drawing; Electroplating a copper layer on the aluminum wire to obtain a copper-clad aluminum wire, stranding multiple groups of the copper-clad aluminum wires through a bunching machine and winding and covering them outside the copper-clad steel wire with a stable drawing process to form a circular conductor structure; Determining whether the stranding and covering process is qualified based on the composite morphology index of the circular conductor structure, and adjusting the production speed or drawing tension according to the relative difference between the composite morphology index and the preset composite morphology index; Coating polyvinyl chloride, cross-linked polyethylene, and fluoroplastics outside the circular conductor structure through an extruder to obtain an insulating layer.

2. The method for preparing an ultra-fine alloy electric wire for an automobile according to claim 1, wherein Determining that the drawing process of the copper-clad steel wire is unstable based on the comparison result that the wire diameter fluctuation of the copper-clad steel wire during the drawing process is greater than the preset wire diameter fluctuation, and determining that there is steel component penetration inside the copper layer according to the comparison result that the copper content of the scrapings under the first layer of detection method is greater than or equal to the preset copper content; Wherein, the first layer of detection method is to scrape the surface copper layer from several sampling points to a depth of 50% of the copper layer thickness, collect the scrapings of each sampling point respectively, and detect whether steel is contained therein.

3. The method for preparing an ultra-fine alloy electric wire for automobiles according to claim 2, characterized in that, Under the condition of determining that there is steel component penetration inside the copper layer, the process of adjusting the current density includes: Dividing the copper content by the preset copper content; Setting several adjustment coefficients corresponding to the corresponding ratio; Increasing the electroplating current density based on several of the adjustment coefficients; Setting the corresponding relationship between the corresponding ratio and the increased electroplating current density to adjust the current density.

4. The method for preparing an ultra-fine alloy wire for an automobile according to claim 1, characterized in that, Determining that the drawing process of the copper-clad steel wire is unstable based on the comparison result that the wire diameter fluctuation of the copper-clad steel wire during the drawing process is greater than the preset wire diameter fluctuation, and determining that there is steel component penetration inside the copper layer according to the comparison result that the iron content of the scrapings under the second layer of detection method is greater than or equal to the preset iron content; Wherein, the second layer of detection method is to scrape the copper layer from several sampling points until the steel core wire is just exposed, collect the scrapings of each sampling point respectively, and detect whether steel is contained therein.

5. The method for preparing an ultra-fine alloy wire for automobiles according to claim 4, characterized in that, Determining that the electroplating process is unqualified based on the comparison result that the coating distribution uniformity of the copper-clad steel wire after drawing is less than or equal to the preset coating distribution uniformity.

6. The method for preparing an ultra-fine alloy electric wire for an automobile according to claim 5, wherein Under the condition of determining that the electroplating process is unqualified, the process of adjusting the electroplating temperature or stirring speed of the electroplating process includes: Taking the absolute value after subtracting the coating distribution uniformity from the preset coating distribution uniformity; Determining to increase the stirring speed with a preset stirring speed adjustment coefficient based on the comparison result that the absolute difference is less than or equal to the preset absolute difference; Determining to increase the electroplating temperature with a preset electroplating temperature adjustment coefficient based on the comparison result that the absolute difference is greater than the preset absolute difference.

7. The method for preparing an ultra-fine alloy electric wire for automobiles according to claim 4, wherein, Determine that the electroplating process is qualified but the wire drawing process is unqualified based on the comparison result that the coating distribution uniformity of the copper-clad steel wire after wire drawing is less than or equal to the preset coating distribution uniformity.

8. The method for preparing an ultra-fine alloy electric wire for automobiles according to claim 7, characterized in that, Under the condition of determining that the electroplating process is qualified but the wire drawing process is unqualified, the process of adjusting the parameters of the wire drawing machine includes: Subtract the coating distribution uniformity from the preset coating distribution uniformity; Based on the comparison result that the difference is less than or equal to the preset difference, determine to reduce the drawing speed of the wire drawing machine with the first preset drawing speed adjustment coefficient; Based on the comparison result that the difference is greater than the preset difference, determine to reduce the drawing speed of the wire drawing machine with the second preset drawing speed adjustment coefficient.

9. The method for preparing an ultra-fine alloy electric wire for an automobile according to claim 1, characterized in that Based on the comparison result that the composite morphology index of the circular conductor structure is less than or equal to the composite morphology index threshold, determine to be less than or equal to the composite morphology index threshold, and according to the comparison result of the relative difference between the composite morphology index threshold and the composite morphology index and the preset relative difference, determine to increase the production speed of the bunching machine with the preset production speed adjustment coefficient or reduce the drawing tension of the wire drawing machine with the preset drawing tension adjustment coefficient.

10. An ultra-fine alloy wire for automobiles, which is prepared by using the method for preparing an ultra-fine alloy wire for automobiles according to any one of claims 1-9, is characterized in that, Including: A copper-clad steel wire, which is used as a conductor to transmit electric energy; A copper-clad aluminum wire, which is coated on the outside of the copper-clad steel wire to protect the copper-clad steel wire; An insulating layer, which is coated on the outside of the copper-clad aluminum wire to provide electrical isolation for the alloy wire.

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