Drawing die set for metal wire rod and method for optimizing the same

Abstract

The application discloses a wire drawing die set of metal wires and an optimization method thereof. The wire drawing die set comprises a middle drawing die group, a small drawing die group and a micro drawing die group. The compression ratio of each pass of each die group is within a preset range, and the number of dies is less than that of conventional wire drawing die sets. The wire outlet diameter of each pass of each die group is sequentially reduced, and the wire outlet diameter of a previous pass is equal to the wire inlet diameter of a subsequent pass. The wire outlet diameter of the last pass of the middle drawing die group is equal to the wire inlet diameter of the first pass of the small drawing die group, and the wire outlet diameter of the last pass of the small drawing die group is equal to the wire inlet diameter of the first pass of the micro drawing die group. Compared with the conventional wire drawing die set, the wire drawing die set provided by the application effectively reduces the number of dies, reduces the manufacturing cost of the wire drawing die set, reduces the friction loss between the metal wires and the dies and the tower wheels and the additional energy consumption of the metal wires in the wire drawing process, reduces the total power consumption in the wire drawing process, and effectively reduces the wire drawing cost of the metal wires.

Description

Technical Field

[0001] This invention relates to the technical field of metal material processing and forming, specifically to a metal wire drawing die assembly and its optimization method. Background Technology

[0002] Copper-clad aluminum wire, with an aluminum core and a concentric copper layer, combines the conductivity of copper with the lightweight and low-cost advantages of aluminum. It is widely used in high-frequency signal transmission, precision electronic components, lightweight motors, transformers, and industrial cables. Under high-frequency transmission conditions, based on the skin effect, the surface copper layer is equivalent to a pure copper conductor, meeting conductivity and solderability requirements, while the aluminum core achieves significant weight reduction and cost reduction. With the development of emerging industries such as 5G communication, new energy vehicles, and aerospace, the demand for micro-gauge copper-clad aluminum wire is increasing daily.

[0003] Currently, copper-clad aluminum wire drawing from conventional diameters to micro-gauges generally employs a segmented, multi-pass drawing process. Due to limitations in the bonding strength of the copper-aluminum composite interface and the work hardening characteristics of the material, the reduction in diameter per pass is limited. In production, large deformation is broken down into independent processes such as large-to-medium drawing, small drawing, and micro drawing. Each process is equipped with a corresponding number of drawing dies to gradually reduce the aperture to the target wire diameter.

[0004] However, the existing copper-clad aluminum wire drawing process has the following shortcomings. First, it has high energy consumption. The intermediate drawing process needs to overcome significant deformation resistance, requiring high drive power and resulting in significant energy consumption. Second, it consumes a large number of dies. Each pass requires high-precision dies, and the number of dies increases cumulatively as the wire diameter decreases. The intermediate drawing process requires large die diameters, high precision, and high wear resistance, leading to high unit costs and replacement and maintenance expenses. Third, the intermediate drawing process involves many passes and takes a long time, affecting the overall line efficiency.

[0005] How to solve the problems of high mold wear and high electricity costs has become a technical challenge that urgently needs to be addressed in this field. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a metal wire drawing die set, including a medium drawing die set, a small drawing die set, and a micro drawing die set; The compression ratios of each pass in the medium-length drawing die group, the small-length drawing die group, and the micro-length drawing die group are within the corresponding preset ranges; The wire exit diameters of the medium drawing die group, small drawing die group, and micro drawing die group decrease sequentially, and the wire exit diameter of the previous pass is equal to the wire inlet diameter of the adjacent next pass. In the medium drawing die group, the final pass exit hole diameter is equal to the first pass inlet hole diameter in the small drawing die group, and in the small drawing die group, the final pass exit hole diameter is equal to the first pass inlet hole diameter in the micro drawing die group.

[0007] Preferably, the compression ratio of the first pass of the intermediate drawing die group is 1.08 to 1.09; the compression ratio of the intermediate passes is 1.255 to 1.262; and the compression ratio of the final pass is 1.248 to 1252. The compression ratio of the first pass of the small drawing die group is 1.13 to 1.14; the compression ratio of the intermediate passes is 1.175 to 1.185; and the compression ratio of the final pass is 1.1 to 1.12. The compression ratio of the first pass of the micro-extrusion die group is 1.2 to 1.25; the compression ratio of the intermediate passes is 1.125 to 1.135; and the compression ratio of the final pass is 1.10 to 1.11.

[0008] Preferably, the first compression ratio in the intermediate drawing die group is 1.085; The intermediate compression ratios in the middle drawing die group are, in sequence, 1.26; The final compression ratio in the middle drawing die group is 1.25.

[0009] Preferably, the compression ratio of the first pass of the small drawing die group is 1.1367; the compression ratio of the intermediate passes is 1.18; and the compression ratio of the final pass is 1.11. The compression ratio of the first pass of the micro-drawing die group is 1.2041; the compression ratio of the intermediate passes is 1.13; and the compression ratio of the final pass is 1.1048.

[0010] Preferably, the final pass wire exit diameter of the intermediate drawing die group is 1.4 mm to 1.5 mm.

[0011] Preferably, the wire exit diameter of the final die of the intermediate drawing die group is 1.45 mm.

[0012] Preferably, the mold core of the medium-stretch die group is made of polycrystalline diamond; The mold cores of the small mold-pulling group are made of single-crystal diamond or natural diamond; The core of the molds used by the micro-pulling mold group is made of natural diamond or polycrystalline diamond.

[0013] The present invention also provides an optimization method for a metal wire drawing die assembly, comprising the following steps: S1, obtain the initial wire diameter and target wire diameter of the metal wire, and match a set of initial mold group parameters from the preset mold group parameter library; S2, adjust the final pass wire exit diameter A of the medium drawing die group, the first pass wire inlet diameter B of the small drawing die group, and the compression ratio of the corresponding dies of the medium drawing die group, small drawing die group, and micro drawing die group in the initial die group parameters to obtain the adjusted initial die group parameters, so that the number of dies in the subsequently obtained optimized wire drawing die group is less than the number of dies in the initial die group, under the premise of meeting the same metal wire drawing process requirements. S3. Based on the first pass inlet diameter, the last pass outlet diameter, and the compression ratio of the medium drawing die group, small drawing die group, and micro drawing die group in the adjusted initial die group parameters, calculate the number of dies in the medium drawing die group, small drawing die group, and micro drawing die group and the inlet and outlet diameters of each die to obtain the optimized parameters of the initial die group. S4. Based on the initial mold set optimization parameters, manufacture the molds corresponding to each pass, and assemble each mold into an optimized mold set suitable for metal wire drawing according to the preset mold matching sequence.

[0014] Preferably, step S2 specifically includes: S21, increase the final pass wire exit diameter A of the medium drawing die group, and simultaneously adjust the first pass wire inlet diameter B of the small drawing die group, wherein the wire exit diameter A is equal to the wire inlet diameter B; S22, reduce the compression ratio of the first pass of the medium drawing die group and increase the compression ratio of the intermediate passes; S23, Increase the compression ratio of the first pass and the compression ratio of the intermediate passes in the small drawing die group; S24, Increase or maintain the first and intermediate compression ratios of the micro-drawing die group.

[0015] Preferably, step S4 specifically includes: S41, based on the number of dies in the medium drawing die group, the small drawing die group, and the micro drawing die group, the inlet diameter, outlet diameter, and compression ratio of each die, manufacture the medium drawing dies for each pass of the medium drawing die group, the small drawing dies for each pass of the small drawing die group, and the micro drawing dies for each pass of the micro drawing die group. S42, according to the preset mold assembly sequence, the intermediate drawing mold, the small drawing mold, and the micro drawing mold of each pass are assembled into corresponding intermediate drawing mold groups, small drawing mold groups, and micro drawing mold groups respectively. S43, assemble the medium drawing die group, small drawing die group and micro drawing die group in sequence into an optimized die group suitable for metal wire drawing.

[0016] The beneficial effects of this invention are as follows: The wire drawing die set provided by this invention has a smaller number of dies than conventional wire drawing die sets in the prior art, because the compression ratio of each pass in each die group is set within a corresponding preset range. This means that in the wire drawing process, without affecting the wire drawing quality and efficiency, the number of dies is effectively reduced compared to the matching conventional wire drawing die set. The reduction in the number of dies effectively reduces the manufacturing cost of the wire drawing die set. At the same time, in the wire drawing process, it can directly reduce the friction loss between the wire and the die and the roller, as well as the additional energy consumption generated by the repeated bending and straightening of the wire, thereby reducing the total power consumption of the wire drawing process and ultimately effectively reducing the manufacturing cost of wire drawing.

[0017] The optimization method for metal wire drawing die sets provided by this invention adjusts the final pass wire exit diameter A of the first die group, the first pass wire inlet diameter B of the second die group, and the compression ratio of the corresponding die in each die group in the initial die set parameters to obtain adjusted initial die set parameters. This ensures that the number of dies in the subsequently optimized drawing die set is less than the number of dies in the initial die set, while meeting the same metal wire drawing process requirements. This reduces the number of dies in each die group compared to the selected initial die set, thereby lowering the manufacturing cost of the optimized drawing die set. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the preparation method of the washing and care composition of the present invention.

[0019] Figure 2 This is a detailed flowchart of the process for S2 in the diagram.

[0020] Figure 3 yes Figure 1 A detailed flowchart of the S4 process.

[0021] Figure 4 This is a schematic diagram of the metal wire drawing die assembly of the present invention.

[0022] Figure 5 This is a schematic diagram of the structure of a conventional wire drawing die assembly in the existing technology. Detailed Implementation

[0023] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be described below in conjunction with specific embodiments.

[0024] See Figure 1 , Figure 1 This is a schematic flowchart of the optimization method for the metal wire drawing die assembly of the present invention. The optimization method for the metal wire drawing die assembly provided by the present invention includes the following steps: S10: Obtain the initial wire diameter and target wire diameter of the metal wire, and match a set of initial mold group parameters from the preset mold group parameter library.

[0025] Preferably, the initial mold group parameters include parameters for the medium-length drawing mold group, the small-length drawing mold group, and the micro-drawing mold group. The parameters for the medium-length drawing mold group include, but are not limited to: the number of molds in the medium-length drawing mold group, and the inlet diameter, outlet diameter, compression ratio, and reduction rate of each mold. The parameters for the small-length drawing mold group include, but are not limited to: the number of molds in the small-length drawing mold group, and the inlet diameter, outlet diameter, compression ratio, and reduction rate of each mold. The parameters for the micro-drawing mold group include, but are not limited to: the number of molds in the micro-drawing mold group, and the inlet diameter, outlet diameter, compression ratio, and reduction rate of each mold.

[0026] S20, adjust the final pass wire exit diameter A of the medium drawing die group, the first pass wire inlet diameter B of the small drawing die group, and the compression ratio of the corresponding dies of the medium drawing die group, small drawing die group, and micro drawing die group in the initial die group parameters to obtain the adjusted initial die group parameters, so that the number of dies in the subsequently obtained optimized wire drawing die group is less than the number of dies in the initial die group, under the premise of meeting the same metal wire drawing process requirements.

[0027] The purpose of adjusting the outlet diameter A, outlet diameter B, and the compression ratio of the corresponding dies in step S20 is to design an optimized wire drawing die set that ensures both the quality and efficiency of wire drawing while reducing the number of dies. To determine the quality of wire drawing, the compression ratio of the dies in the drawing die set must be within an appropriate range and increased within that range. This allows for a reduction in the number of dies while maintaining the same initial inlet diameter and final outlet diameter for the entire drawing die set.

[0028] In step S20, if the initial mold group parameters include the parameters of the medium drawing mold group, the small drawing mold group, and the micro drawing mold group, then the first mold group parameter is the parameter of the medium drawing mold group, and the second mold group parameter is the parameter of the small drawing mold group. That is, the outlet diameter A is the outlet diameter of the last pass of the medium drawing mold group; and the inlet diameter B is the outlet diameter of the last pass of the small drawing mold group.

[0029] See Figure 2 , Figure 2 This is a detailed flowchart illustrating step S20 in the diagram. The steps in S20 specifically include: S21, increase the final pass wire exit diameter A of the medium drawing die group, and simultaneously adjust the first pass wire inlet diameter B of the small drawing die group, wherein the wire exit diameter A is equal to the wire inlet diameter B; S22, reduce the compression ratio of the first pass of the medium drawing die group and increase the compression ratio of the intermediate passes; S23, Increase the compression ratio of the first pass and the compression ratio of the intermediate passes in the small drawing die group; S24, Increase or maintain the first and intermediate compression ratios of the micro-drawing die group.

[0030] In this invention, the parameters that need to be adjusted need to be preset. Generally, the compression ratio of the first and intermediate passes of each die group can be preset, but the compression ratio of the final pass cannot be preset and needs to be adjusted according to the actual situation. One of the objectives of this invention is to provide a wire drawing die group that can ensure the quality and efficiency of metal wire drawing while requiring fewer dies, thereby reducing the manufacturing cost of the wire drawing die group. In metal wire drawing dies, the price of medium-sized drawing dies is generally higher than that of micro-drawing dies, and the price of micro-drawing dies is slightly higher than that of small drawing dies. This is because medium-sized drawing dies use thicker and heavier blanks and require more material, resulting in higher prices; micro-drawing dies are more expensive due to the difficulty of ultra-precision machining; and small drawing dies are relatively cheaper due to mature technology, large-scale standardized production, and lower prices.

[0031] Specifically, this invention reduces the number of dies in the final pass of the intermediate drawing die group by increasing the final pass wire exit diameter in the intermediate drawing die group parameters and appropriately increasing the intermediate pass compression ratio of the intermediate drawing die group while ensuring wire drawing quality under the intermediate drawing conditions.

[0032] Furthermore, in the metal wire drawing process, to ensure the quality of the drawn metal wire and achieve stable continuous production, it is necessary to control the workload of the die head of the metal wire drawing system. The initial compression ratio of the intermediate drawing die group affects the workload of the die head; when the initial compression ratio of the intermediate drawing die group decreases, the corresponding single-pass deformation decreases, the drawing force decreases, and the torque and power required by the die head motor also decrease, thus reducing the workload of the die head. Conversely, increasing the initial compression ratio of the intermediate drawing die group increases the workload of the die head. Therefore, this invention reduces the workload of the die head by decreasing the initial compression ratio of the intermediate drawing die group.

[0033] For small die-drawing groups, the number of dies can be reduced by appropriately increasing the compression ratio of the first pass and the compression ratio of the intermediate passes.

[0034] Metal wires undergo numerous drawing passes during the intermediate and minor drawing processes, resulting in significant work hardening and low tensile strength. Even a slight increase in the compression ratio makes them prone to breakage. Simultaneously, the hardened surface layer constitutes a large volume, and due to its extremely low plasticity, it is highly susceptible to micro-cracks that propagate rapidly under drawing stress, leading to wire breakage. Therefore, the compression ratio of the micro-drawing die group cannot be adjusted excessively. This invention addresses this by appropriately increasing the compression ratio of the first and intermediate passes to reduce the number of dies; alternatively, the original compression ratio can be maintained, keeping the original number of dies and the compression ratio of each pass intact; or, adaptive fine-tuning can be made according to actual conditions.

[0035] S30. Based on the first pass inlet diameter, last pass outlet diameter, and compression ratio of the medium drawing die group, small drawing die group, and micro drawing die group in the adjusted initial die group parameters, calculate the number of dies in the medium drawing die group, small drawing die group, and micro drawing die group, and the inlet and outlet diameters of each die, to obtain the optimized parameters of the initial die group.

[0036] The steps in S30 specifically include the following processing: For the intermediate drawing die group, calculate the inlet and outlet diameters of the first pass based on the initial wire diameter and the compression ratio of the first pass. Calculate the number of intermediate dies and the inlet and outlet diameters of each die based on the outlet diameters of the first and last passes, as well as the compression ratios of the intermediate passes. Determine the inlet diameter and compression ratio of the last pass in the intermediate passes based on the outlet diameter of the last pass in the group, thus obtaining the number of dies in the group and the inlet, outlet, and compression ratios of each die.

[0037] For a small die group, the first pass exit diameter is determined based on the first pass inlet diameter B and the first pass compression ratio. The first pass exit diameter is the second pass inlet diameter. Based on the second pass inlet diameter, the last pass exit diameter, and the intermediate pass compression ratios, the inlet and outlet diameters of the intermediate passes, as well as the number of intermediate pass dies, are calculated. Based on the last pass exit diameter of the intermediate passes and the last pass exit diameter of the group, the inlet diameter and compression ratio of the last pass are calculated, thus obtaining the number of dies in the group and the inlet / outlet diameter and compression ratio of each die.

[0038] For small drawing die groups, if the calculated final pass compression ratio is too low, the final pass exit hole diameter can be appropriately reduced to ensure that the final determined final pass compression ratio meets the small drawing process requirements. Simultaneously, the first pass inlet hole diameter of the micro drawing die group should also be reduced.

[0039] For the micro-drawing die group, based on the final determined inlet and outlet diameters of the first pass, the outlet diameter of the last pass, the compression ratio of the first pass, and the compression ratios of the intermediate passes, calculate the inlet and outlet diameters of the first and intermediate passes, as well as the number of intermediate passes dies. Based on the outlet diameter of the last intermediate pass and the outlet diameter of the last pass of the group, determine the inlet diameter and compression ratio of the last pass of the group, thus obtaining the number of dies for the group and the inlet and outlet diameters and compression ratios of each die.

[0040] The final optimized parameters for the initial die set obtained above include the following three sets of data: 1. The number of dies in the medium-length drawing die group and the inlet and outlet diameters and compression ratio of each die. 2. The number of dies in the small-length drawing die group and the inlet and outlet diameters and compression ratio of each die. 3. The number of dies in the micro-drawing die group and the inlet and outlet diameters and compression ratio of each die.

[0041] S40: Based on the initial mold set optimization parameters, manufacture molds corresponding to each pass, and assemble each mold into an optimized mold set suitable for metal wire drawing according to the preset mold matching sequence.

[0042] See Figure 3 , Figure 3 yes Figure 1 A detailed flowchart illustrating the process of S40. The steps of S4 specifically include: S41, based on the number of dies in the medium drawing die group, the small drawing die group, and the micro drawing die group, the inlet diameter, outlet diameter, and compression ratio of each die, manufacture the medium drawing dies for each pass of the medium drawing die group, the small drawing dies for each pass of the small drawing die group, and the micro drawing dies for each pass of the micro drawing die group.

[0043] S42, according to the preset die assembly sequence, assemble the intermediate drawing die, the small drawing die, and the micro drawing die of each pass into corresponding intermediate drawing die groups, small drawing die groups, and micro drawing die groups respectively.

[0044] S43, assemble the medium drawing die group, small drawing die group and micro drawing die group in sequence into an optimized die group suitable for metal wire drawing.

[0045] Now, taking the optimization of a drawing die set for copper-clad aluminum wire with an initial wire diameter of 3 mm and a target wire diameter of 0.09 mm as an example, the optimization method of the drawing die set for metal wire of the present invention will be further explained.

[0046] First, the initial wire diameter of 3 mm and the target wire diameter of 0.09 mm are obtained. A set of initial die group parameters is then matched from a pre-set die parameter library. These initial die group parameters include: intermediate drawing die group parameters, small drawing die group parameters, and micro drawing die group parameters. Specifically, the intermediate drawing die group parameters include: first pass wire inlet diameter of 3 mm, last pass wire outlet diameter of 1 mm, 17 dies, a compression ratio of 1.14, and a reduction rate of 12.44%. The small drawing die group parameters include: first pass wire inlet diameter of 1 mm, last pass wire outlet diameter of 0.4 mm, 24 dies, a compression ratio of 1.079, and a reduction rate of 7.4%. The micro drawing die group parameters include: first pass wire inlet diameter of 0.4 mm, last pass wire outlet diameter of 0.09 mm, 24 dies, a compression ratio of 1.131, and a reduction rate of 11.58%.

[0047] Then, based on preset values, the final pass wire exit diameter in the parameters of the intermediate drawing die group was adjusted from 1 mm to 1.45 mm. Correspondingly, the first pass wire inlet diameter in the parameters of the small drawing die group was also adjusted from 1 mm to 1.45 mm. The first pass compression ratio of the intermediate drawing die group was adjusted from 1.14 to 1.085, and the intermediate pass compression ratio was adjusted from 1.14 to 1.26. The first pass compression ratio of the small drawing die group was adjusted from 1.079 to 1.1367, and the intermediate pass compression ratio was adjusted from 1.079 to 1.18. The first pass compression ratio of the micro drawing die group was adjusted from 1.131 to 1.2041, and the intermediate pass compression ratio was adjusted from 1.131 to 1.13. That is, the intermediate pass compression ratio of the micro drawing die group was not adjusted.

[0048] For the intermediate drawing die group, based on the first pass inlet diameter of 3 mm and the first pass die compression ratio of 1.085, the first pass inlet diameter of 3 mm, outlet diameter of 2.88 mm, and compression ratio of 1.085 were calculated and determined, thus defining the first pass die parameters for the intermediate drawing die group. Then, based on the first pass outlet diameter of 2.88 mm, the intermediate pass compression ratio of 1.26, and the final pass outlet diameter of 1.45 mm, the number of intermediate passes dies, and the inlet / outlet diameter and compression ratio of each die were calculated and determined. The specific calculation results are shown in Table 1. During the specific calculation process, when calculating the die parameters for the 7th pass, it was found that if the 6th pass outlet diameter was used as the 7th pass inlet diameter, the 7th pass outlet diameter, calculated using the 7th pass inlet diameter and the pre-adjusted compression ratio of 1.26, was less than 1.45 mm, which is less than the final pass outlet diameter of the intermediate drawing die group. If the compression ratio does not change significantly compared to other passes without altering the final pass's outlet diameter, the pre-adjusted final pass outlet diameter is retained. In this embodiment, the final pass outlet diameter of the intermediate drawing die group (1.45) is used as the outlet diameter for the 7th pass. Then, based on the inlet and outlet diameters of the 7th pass, the compression ratio for the 7th pass is calculated to be 1.25. The final optimized parameters for the intermediate drawing die group are shown in Table 1.

[0049] Table 1: Optimization Parameters for the Medium-Draw Die Group

[0050] For the small drawing die group, based on the first pass inlet diameter of 1.45 mm, the first pass compression ratio of 1.1367, and the intermediate pass compression ratio of 1.18, the parameters of the first pass die, the number of intermediate pass dies, and the parameters of each intermediate pass die were calculated and determined. The specific calculation results are shown in Table 2. During the calculation process, when calculating the parameters for the 15th pass die, it was found that if the 15th pass outlet diameter was used as the 16th pass inlet diameter, and the 16th pass inlet diameter was calculated using the pre-adjusted compression ratio of 1.18, the 16th pass outlet diameter would be less than 0.4 mm. If the compression ratio was determined based on the 16th pass inlet diameter and 0.4 mm as the 16th pass outlet diameter, the compression ratio might be too small to meet the requirements of the small drawing process. At this point, the exit hole diameter of the final pass (pass 16) of the small drawing die group can be appropriately reduced, for example, by adjusting the exit hole diameter of pass 16 to 0.398 mm. Simultaneously, the inlet hole diameter of the first pass of the micro-drawing die group should also be adjusted to 0.398 mm. Based on the inlet and outlet hole diameters of pass 16, the compression ratio of pass 16 is calculated to be 1.11, which meets the requirements of the small drawing process. The final optimized parameters for the small drawing die group are shown in Table 2.

[0051] Table 2: Optimization Parameters for Small Die Pulling Group

[0052] For the micro-drawing die group, based on the first pass inlet diameter of 0.398 mm, the first pass compression ratio of 1.2041, the intermediate pass compression ratio of 1.13, and the final pass outlet diameter of 0.09 mm, the parameters of the first pass die, the number of intermediate pass dies, and the parameters of each intermediate pass die were calculated and determined. The specific calculation results are shown in Table 3. During the calculation process, when calculating the parameters for the 24th pass die, it was found that if the outlet diameter of the 23rd pass was used as the inlet diameter of the 24th pass, the outlet diameter of the 24th pass, calculated using the inlet diameter of the 24th pass and the pre-adjusted compression ratio of 1.13, was less than 0.09 mm, which is smaller than the final pass outlet diameter of the micro-drawing die group. However, this final pass outlet diameter, as the target wire diameter, cannot be changed. Therefore, the final pass wire diameter of the micro-drawing die group (0.09) needs to be used as the pass wire diameter for the 24th pass. Then, based on the pass wire diameters of the 24th pass, the compression ratio of the 24th pass is calculated to be 1.1048, which meets the requirements of the micro-drawing process. The final optimized parameters for the micro-drawing die group are shown in Table 3.

[0053] Table 3: Optimization Parameters for the Micro-Die Group

[0054] Finally, based on the number of dies in the medium-drawing die group, the inlet and outlet diameters of each die, and the compression ratio, the medium-drawing dies for each pass are manufactured. Based on the number of dies in the small-drawing die group, the inlet and outlet diameters of each die, and the compression ratio, the small-drawing dies for each pass are manufactured. Based on the number of dies in the micro-drawing die group, the inlet and outlet diameters of each die, and the compression ratio, the micro-drawing dies for each pass are manufactured. The medium-drawing dies for each pass are assembled into a medium-drawing die group according to a preset die-matching sequence. The small-drawing dies for each pass are assembled into a small-drawing die group according to a preset die-matching sequence. The micro-drawing dies for each pass are assembled into a micro-drawing die group according to a preset die-matching sequence. Then, the medium-drawing die group, the small-drawing die group, and the micro-drawing die group are assembled sequentially into an optimized wire drawing die group for metal wire.

[0055] The optimized wire drawing die assembly of this invention is installed in a continuous wire drawing process system. The process system, along the direction of process travel, sequentially includes a wire feeding device, an inlet guide wheel, a lubrication and cooling device, various levels of wire drawing dies composed of the aforementioned optimized die assembly, a tower wheel / winch drive mechanism, an outlet guide wheel, and a wire take-up device.

[0056] In specific applications, copper-clad aluminum wire of the same batch and specification with an initial wire diameter of 3 mm is selected. Under conventional wire drawing process conditions (the temperature of the wire drawing lubricant is controlled at 40-50℃ and the cooling water flow rate is 100 L / min), the copper-clad aluminum wire is passed through a multi-stage optimized wire drawing die set for continuous stretching. Finally, it is wound up to obtain the finished copper-clad aluminum wire corresponding to Example 1 with a target diameter of 0.09 mm.

[0057] For comparative verification, in the same process system described above, only the optimized wire drawing die set was replaced with the original wire drawing die set. The same copper-clad aluminum wire and process parameters were used for wire drawing, and finally the finished copper-clad aluminum wire with a target diameter of 0.09 mm was obtained by winding.

[0058] To demonstrate that the copper-clad aluminum wire produced using the optimized drawing die set provided by this invention fully meets the drawing quality requirements and subsequent process standards, the following performance indicators were tested on the finished copper-clad aluminum wires of Example 1 and Comparative Example 1. All tests were conducted at room temperature (25±2℃), and the test results are shown in Table 4.

[0059] Table 4:

[0060] According to the test results shown in Table 4, after applying the optimized wire drawing die set of the present invention, the wire diameter deviation, out-of-roundness, surface roughness, tensile strength, elongation and torsional performance of the finished copper-clad aluminum metal wire are all at the same level as the die set before optimization, and fully meet the national standard for the process requirements of incoming materials.

[0061] To verify the impact of the optimized wire drawing die set provided by this invention on production efficiency, various efficiency indicators were statistically analyzed by online monitoring of the systems corresponding to Example 1 and Comparative Example 1 under continuous production conditions. Specific detection and statistical methods are shown in Table 5.

[0062] Table 5:

[0063] According to the test results shown in Table 5, after adopting the optimized wire drawing die set of the present invention, the wire drawing speed can remain at the original high level. Moreover, due to the optimization of the die structure, the stress state is improved, the wire breakage rate is significantly reduced, and the output per shift is slightly increased.

[0064] To verify the outstanding effect of the optimized wire drawing die set provided by the present invention in reducing material and energy consumption, a special test was conducted on die wear and power consumption, as shown in Table 6.

[0065] Table 6:

[0066] As shown in Table 6, the test results indicate that this invention effectively reduces mold hole wear and decreases the frequency of mold replacement and repair by optimizing the stress distribution and frictional heat dissipation conditions in the mold working area. The energy savings from restarting due to reduced friction and fewer broken wires result in lower power consumption per unit product.

[0067] In summary, the optimized wire drawing die set provided by this invention, applied to a metal wire drawing process system, significantly reduces the number of dies compared to traditional conventional die sets, directly lowering die manufacturing costs. Simultaneously, the reduction in the number of online dies also reduces the consumption of auxiliary materials such as lubricants and coolants. Secondly, the finished metal wire exhibits wire diameter accuracy, surface quality, tensile strength, and elongation that meet or exceed the levels of traditional conventional dies, fully complying with industry acceptance standards. Furthermore, high-speed wire drawing efficiency is maintained, and the rate of wire breakage downtime is significantly reduced. In addition, the reduced number of dies allows for a more reasonable load on each die set, which is beneficial for die protection and extends the replacement cycle.

[0068] See Figure 4 , Figure 4 This is a schematic diagram of the metal wire drawing die assembly of the present invention. See also... Figure 4 The wire drawing die group 10 includes a medium drawing die group 11, a small drawing die group 12, and a micro drawing die group 13. Within a preset range corresponding to the compression ratio of each pass in the medium drawing die group 11, the small drawing die group 12, and the micro drawing die group 13, the wire exit diameter of each pass decreases sequentially, and the wire exit diameter of the previous pass is equal to the wire inlet diameter of the adjacent next pass. The wire exit diameter of the last pass in the medium drawing die group 11 is equal to the wire inlet diameter of the first pass in the small drawing die group 12, and the wire exit diameter of the last pass in the small drawing die group 12 is equal to the wire inlet diameter of the first pass in the micro drawing die group 13.

[0069] The wire drawing die set provided by this invention is suitable for metal wires with an initial wire diameter of 3 mm and a target wire diameter of 0.09 mm. Specifically, the first pass wire inlet diameter in the intermediate drawing die set 11 is 3 mm, and the final pass wire outlet diameter in the micro-drawing die set 13 is 0.09 mm. See also... Figure 5 , Figure 5This is a schematic diagram of the structure of a conventional wire drawing die group in the prior art. Specifically, the conventional wire drawing die group 20 matched with it in the prior art includes a medium drawing die group 21, a small drawing die group 22, and a micro drawing die group 23. The medium drawing die group 21 has a first-pass wire inlet diameter of 3 mm and a last-pass wire outlet diameter of 1 mm, with 17 dies, specifically including the 1st-pass medium drawing die, the 2nd-pass medium drawing die... the 16th-pass medium drawing die, and the 17th-pass medium drawing die, with a compression ratio of 1.14. The small drawing die group 22 has a first-pass wire inlet diameter of 1 mm and a last-pass wire outlet diameter of 0.4 mm, with 24 dies, specifically including the 1st-pass small drawing die, the 2nd-pass small drawing die... the 23rd-pass small drawing die, and the 24th-pass small drawing die, with a compression ratio of 1.079. The first pass inlet diameter of the micro-drawing die group 23 is 0.4 mm, the last pass outlet diameter is 0.09 mm, and the number of dies is 24, specifically including the first pass micro-drawing die, the second pass micro-drawing die... the 23rd pass micro-drawing die, and the 24th pass micro-drawing die, with a compression ratio of 1.131.

[0070] In the wire drawing die group for metal wire provided by the present invention, the compression ratio of the first pass of the intermediate drawing die group 11 is 1.08 to 1.09; the compression ratio of the intermediate passes is 1.255 to 1.262; and the compression ratio of the last pass is 1.248 to 1252.

[0071] The compression ratio of the first pass of the above-mentioned drawing die group 10 is relatively small, much smaller than that of other passes. With this setting, the metal wire deforms smoothly in the die hole of the first pass, and the stress on each part is uniform. It will not generate excessive stress peaks in local areas, which is conducive to ensuring the uniformity of the internal structure of the metal wire. At the same time, the scraping and squeezing of the surface of the metal wire during the drawing process is relatively gentle, which is conducive to protecting the surface quality of the metal wire.

[0072] In order to ensure the quality of metal wire drawing and achieve stable continuous production, it is necessary to control the working load of the wire drawing system head.

[0073] Reducing the initial compression ratio of the intermediate drawing die group 11 can decrease the workload of the die head. As the initial compression ratio of the intermediate drawing die group 11 decreases, the corresponding single-pass deformation decreases, the drawing force decreases, and the torque and power required by the die head motor also decrease, thus reducing the workload of the die head.

[0074] In this invention, the wire exit diameter of the final die of the intermediate drawing die group is 1.4 mm to 1.5 mm, preferably 1.45 mm. Compared with the corresponding wire drawing die group 20 in the prior art, the final wire exit diameter of the intermediate drawing die group 21 is increased. Based on the increased wire inlet diameter and the pre-set appropriate compression ratio, the number of dies is reduced. The reduction in the number of dies in the intermediate drawing process can reduce the auxiliary operation time such as compression die threading, die adjustment, die repair, and wire breakage recovery while maintaining the same output and quality of metal wire drawing, thereby improving the production efficiency of the intermediate drawing process.

[0075] The final pass compression ratio of the small drawing die group 12 is 1.1 to 1.12, and the compression ratios of the remaining passes are 1.175 to 1.185. Although the first pass wire inlet diameter of the small drawing die group 12 in this invention is larger than that of the first pass wire inlet diameter in the conventional small drawing die group 22, the final calculated number of dies is appropriately reduced compared to the conventional wire drawing die group because the compression ratios of each pass of the small drawing die group 12 are appropriately increased (the compression ratio setting must ensure the wire drawing output and wire drawing quality of the same metal wire).

[0076] The compression ratio of the final pass of the micro-drawing die group 12 is 1.1 to 1.105, and the compression ratio of the remaining passes is 1.125 to 1.135. The compression ratio of the final pass in the medium-drawing die group 11, small-drawing die group 12, and micro-drawing die group 12 of this invention cannot be guaranteed to be consistent with the compression ratios of the other passes in the corresponding die group; it needs to be determined based on the exit hole diameter of the previous pass and the exit hole diameter of the corresponding final pass in the corresponding die group.

[0077] In the wire drawing die set 10 provided by this invention, the die core of the medium drawing die set 11 is made of polycrystalline diamond. The die core of the small drawing die set 12 is made of monocrystalline diamond or natural diamond. The die core of the micro drawing die set 12 is made of natural diamond or polycrystalline diamond.

[0078] See Figure 4This invention provides an embodiment 1 of a wire drawing die group 10 for metal wires. In this embodiment 1, the compression ratio of the first pass of the intermediate drawing die group 11 is 1.085, the compression ratio of each intermediate pass is 1.26, and the compression ratio of the final pass is 1.25. It includes a total of 7 intermediate drawing dies, specifically the 1st intermediate drawing die, the 2nd intermediate drawing die…the 6th intermediate drawing die, and the 7th intermediate drawing die. Specific parameters are shown in Table 1. The compression ratio of the final pass of the small drawing die group 12 is 1.11, and the compression ratio of the remaining passes is 1.18. It includes a total of 16 small drawing dies, specifically the 1st small drawing die, the 2nd small drawing die…the 15th small drawing die, and the 16th small drawing die. Specific parameters are shown in Table 2. The compression ratio of the final pass of the micro-drawing die group 13 is 1.1048, and the compression ratio of the remaining passes is 1.13. It includes a total of 24 micro-drawing dies, specifically the first pass micro-drawing die, the second pass micro-drawing die, ... the 23rd pass micro-drawing die, and the 24th pass micro-drawing die. For specific parameters, please refer to Table 3.

[0079] The wire drawing die set 10 provided in this embodiment 1 is obtained by the above-mentioned optimization method of the wire drawing die set for metal wires. The test results of various performance indicators in the specific application of the wire drawing process are shown in Tables 4, 5 and 6, and will not be repeated here.

[0080] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A wire drawing die assembly for metal wire, characterized in that, This includes medium-sized drawing die group, small drawing die group, and micro drawing die group; The compression ratios of each pass in the medium-length drawing die group, the small-length drawing die group, and the micro-length drawing die group are within the corresponding preset ranges; The wire exit diameters of the medium drawing die group, small drawing die group, and micro drawing die group decrease sequentially, and the wire exit diameter of the previous pass is equal to the wire inlet diameter of the adjacent next pass. In the medium drawing die group, the final pass exit hole diameter is equal to the first pass inlet hole diameter in the small drawing die group, and in the small drawing die group, the final pass exit hole diameter is equal to the first pass inlet hole diameter in the micro drawing die group.

2. The wire drawing die assembly for metal wire according to claim 1, characterized in that, The compression ratio of the first pass of the intermediate drawing die group is 1.08 to 1.09; the compression ratio of the intermediate passes is 1.255 to 1.262; and the compression ratio of the final pass is 1.248 to 1252. The compression ratio of the first pass of the small drawing die group is 1.13 to 1.14; the compression ratio of the intermediate passes is 1.175 to 1.185; and the compression ratio of the final pass is 1.1 to 1.

12. The compression ratio of the first pass of the micro-extrusion die group is 1.2 to 1.25; the compression ratio of the intermediate passes is 1.125 to 1.135; and the compression ratio of the final pass is 1.10 to 1.

11.

3. The wire drawing die assembly for metal wire according to claim 2, characterized in that, The first compression ratio in the medium-length drawing die group is 1.085; The intermediate compression ratios in the middle drawing die group are, in sequence, 1.26; The final compression ratio in the middle drawing die group is 1.

25.

4. The wire drawing die assembly for metal wires according to claim 2, characterized in that, The compression ratio of the first pass of the small die group is 1.1367; the compression ratio of the intermediate passes is 1.18; and the compression ratio of the final pass is 1.

11. The compression ratio of the first pass of the micro-drawing die group is 1.2041; the compression ratio of the intermediate passes is 1.13; and the compression ratio of the final pass is 1.1048.

5. The wire drawing die assembly for metal wires according to claim 1, characterized in that, The final pass exit hole diameter of the medium drawing die group is 1.4 mm to 1.5 mm.

6. The wire drawing die assembly for metal wires according to claim 5, characterized in that, The wire exit hole diameter of the final die in the middle drawing die group is 1.45 mm.

7. The wire drawing die assembly for metal wire according to any one of claims 1 to 6, characterized in that, The mold core of the medium-stretch die group is made of polycrystalline diamond; The mold cores of the small mold-pulling group are made of single-crystal diamond or natural diamond; The core of the molds used by the micro-pulling mold group is made of natural diamond or polycrystalline diamond.

8. An optimization method for a metal wire drawing die assembly, characterized in that, Includes the following steps: S1, obtain the initial wire diameter and target wire diameter of the metal wire, and match a set of initial mold group parameters from the preset mold group parameter library; S2, adjust the final pass wire exit diameter A of the medium drawing die group, the first pass wire inlet diameter B of the small drawing die group, and the compression ratio of the corresponding dies of the medium drawing die group, small drawing die group, and micro drawing die group in the initial die group parameters to obtain the adjusted initial die group parameters, so that the number of dies in the subsequently obtained optimized wire drawing die group is less than the number of dies in the initial die group, under the premise of meeting the same metal wire drawing process requirements. S3. Based on the first pass inlet diameter, the last pass outlet diameter, and the compression ratio of the medium drawing die group, small drawing die group, and micro drawing die group in the adjusted initial die group parameters, calculate the number of dies in the medium drawing die group, small drawing die group, and micro drawing die group and the inlet and outlet diameters of each die to obtain the optimized parameters of the initial die group. S4. Based on the initial mold set optimization parameters, manufacture the molds corresponding to each pass, and assemble each mold into an optimized mold set suitable for metal wire drawing according to the preset mold matching sequence.

9. The method for optimizing the metal wire drawing die set according to claim 8, characterized in that, The steps in S2 specifically include: S21, increase the final pass wire exit diameter A of the medium drawing die group, and simultaneously adjust the first pass wire inlet diameter B of the small drawing die group, wherein the wire exit diameter A is equal to the wire inlet diameter B; S22, reduce the compression ratio of the first pass of the medium drawing die group and increase the compression ratio of the intermediate passes; S23, Increase the compression ratio of the first pass and the compression ratio of the intermediate passes in the small drawing die group; S24, Increase or maintain the first and intermediate compression ratios of the micro-drawing die group.

10. The method for optimizing the metal wire drawing die assembly according to claim 8, characterized in that, The steps in S4 specifically include: S41, based on the number of dies in the medium drawing die group, the small drawing die group, and the micro drawing die group, the inlet diameter, outlet diameter, and compression ratio of each die, manufacture the medium drawing dies for each pass of the medium drawing die group, the small drawing dies for each pass of the small drawing die group, and the micro drawing dies for each pass of the micro drawing die group. S42, according to the preset mold assembly sequence, the intermediate drawing mold, the small drawing mold, and the micro drawing mold of each pass are assembled into corresponding intermediate drawing mold groups, small drawing mold groups, and micro drawing mold groups respectively. S43, assemble the medium drawing die group, small drawing die group and micro drawing die group in sequence into an optimized die group suitable for metal wire drawing.

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