A method and system for continuous drawing and densification of copper wire

Abstract

This invention relates to the field of metal processing technology, and more particularly to a method and system for continuous drawing and densification of copper wire. The method includes: setting a coolant channel in a drawing die; introducing a first cooling medium into the coolant channel during the drawing process, and continuously monitoring the temperature difference of the first cooling medium; when the temperature difference is less than a set threshold, reducing the temperature of the first cooling medium, and simultaneously activating a spray device to spray a second cooling medium onto the copper wire moving from the drawing die; wherein the temperature of the second cooling medium is lower than the temperature of the first cooling medium, and the temperature of the first cooling medium, after being reduced, is higher than the temperature of the second cooling medium. This invention, by monitoring the inlet and outlet temperature difference and setting a threshold, can accurately determine the thermal load status of the cooling system, avoiding energy waste or insufficient cooling in traditional fixed cooling modes; when the temperature difference is lower than the threshold, dual cooling is triggered in conjunction, breaking through the thermal management bottleneck of a single cooling method, ensuring that the copper wire is prevented from softening during the drawing process, and guaranteeing the densification effect.

Description

Technical Field

[0001] This invention relates to the field of metal processing technology, and in particular to a method and system for continuous drawing and densification of copper wire. Background Technology

[0002] Copper wire can be continuously drawn to compress internal defects, thereby improving the density of its microstructure and enhancing its mechanical properties.

[0003] During drawing, the copper wire experiences intense friction with the inner wall of the die, generating frictional heat. During plastic deformation of the copper wire, energy consumed by lattice slip and dislocation movement is partially converted into deformation heat. If the cooling system is inefficient, this frictional and deformation heat cannot dissipate in time, leading to a significant increase in the local temperature of the copper wire. The strength and yield stress of copper decrease exponentially with increasing temperature. At high temperatures, atomic mobility increases, dislocation slip resistance decreases, and the material undergoes thermal softening.

[0004] Closing internal defects such as pores and microcracks requires high hydrostatic pressure, i.e., triaxial compressive stress. The sources include the radial compressive force of the die on the copper wire and the lateral pressure converted from the axial drawing force. After the material softens, the drawing force required for the same amount of deformation decreases, and the radial compressive force weakens accordingly. At high temperatures, the fluidity of copper increases, and the stress is more easily released through plastic relaxation, resulting in a decrease in hydrostatic pressure level. This makes the driving force for pressing defects insufficient, and under such circumstances, the densification goal to be achieved by drawing often cannot be achieved. Summary of the Invention

[0005] This invention provides a method and system for continuous drawing and densification of copper wire, which can effectively solve the problems in the background art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for densifying copper wire through continuous drawing includes:

[0008] Coolant channels are incorporated into the drawing die;

[0009] During the drawing process, a first cooling medium is introduced into the coolant channel, and the temperature difference of the first cooling medium at the outlet and inlet of the coolant channel is continuously monitored.

[0010] When the temperature difference is less than a set threshold, the temperature of the first cooling medium is reduced, and at the same time, the spray device is turned on at the outlet of the drawing die to spray the second cooling medium onto the copper wire moving out of the drawing die.

[0011] Wherein, the temperature of the second cooling medium is lower than the temperature of the first cooling medium, and the temperature of the first cooling medium, after decreasing, is higher than the temperature of the second cooling medium.

[0012] Furthermore, the first cooling medium and the second cooling medium are the same medium, and the first cooling medium reduces the temperature by mixing with the second cooling medium.

[0013] Furthermore, when the temperature difference is less than a set threshold, the action of reducing the temperature of the first cooling medium is performed after 0.1 to 2 seconds.

[0014] A continuous drawing densification system for copper wire includes:

[0015] The drawing die is provided with a coolant flow channel for the first cooling medium to circulate;

[0016] The temperature monitoring module monitors the temperature difference between the first cooling medium at the outlet and inlet of the coolant flow channel;

[0017] A spraying device is installed at the outlet of the drawing die for spraying a second cooling medium onto the copper wire;

[0018] The control module acquires the temperature difference, and when the temperature difference is less than a set threshold, issues a cooling command for the first cooling medium and simultaneously starts the spray device.

[0019] The medium supply module provides a first cooling medium and a second cooling medium, respectively.

[0020] Wherein, the temperature of the second cooling medium is lower than the temperature of the first cooling medium, and the temperature of the first cooling medium, after decreasing, is higher than the temperature of the second cooling medium.

[0021] Furthermore, the first cooling medium and the second cooling medium are made of the same material;

[0022] The drawing die is also provided with an auxiliary medium flow channel, which is connected to the coolant flow channel;

[0023] The auxiliary medium channel is used to introduce the second cooling medium into the coolant channel to reduce the temperature of the first cooling medium in the channel.

[0024] Furthermore, when the temperature difference is less than a set threshold, the cooling command of the first cooling medium is issued after 0.1 to 2 seconds.

[0025] Furthermore, the coolant flow channel includes at least two flow branches, one end of each flow branch is connected by a first annular branch, and the other end is connected by a second annular branch. The first annular branch and the second annular branch are respectively connected to the inlet and the outlet.

[0026] The drawing die is also provided with an auxiliary medium flow channel, which is an annular flow channel that is coaxial with and connected to the first annular branch, and has an annular open end;

[0027] The spraying device has a ring structure with a protruding stop ring. The sidewall of the stop ring is embedded in the auxiliary medium flow channel. The third annular branch inside the spraying device is connected to the spraying position and the auxiliary medium flow channel through the first hole and the second hole, respectively.

[0028] When the second cooling medium flows into the third annular branch, the spraying device opens the connection position between the second hole and the auxiliary medium flow channel by moving relative to the drawing die; otherwise, the connection position is closed.

[0029] Furthermore, the drawing die includes a main body, and an inner ring and an outer ring disposed at one end of the main body;

[0030] A first annular branch and an auxiliary medium flow channel are formed between the inner and outer annular bodies through a stepped surface transition;

[0031] The second hole in the spray device is positioned facing the stepped surface. When the spray device is in contact with the stepped surface, the second hole is blocked by the stepped surface, thus closing the connection position.

[0032] Furthermore, the second cooling medium flowing out from the second orifice applies pressure to the stepped surface, and the spray device moves under the reaction force to open the connecting position.

[0033] Furthermore, a limit device and a reset device are provided between the drawing die and the spraying device;

[0034] The limiting device is used to limit the maximum distance of movement of the spraying device relative to the drawing die;

[0035] When the spraying stops, the reset device applies force to the spraying device relative to the drawing die to reset it, thereby closing the connection position.

[0036] The technical solution of this invention can achieve the following technical effects:

[0037] In this invention, by monitoring the temperature difference between the inlet and outlet of the cooling medium and setting a threshold, the thermal load status of the cooling system can be accurately determined, avoiding energy waste or insufficient cooling in the traditional fixed cooling mode; when the temperature difference is lower than the threshold, dual cooling is triggered in a linkage manner, breaking through the thermal management bottleneck of a single cooling method, ensuring that the copper wire is always in a suitable temperature window during the drawing process, ensuring that the copper wire is prevented from softening during the drawing process, and ensuring the densification effect.

[0038] In the dual cooling process, the temperature of the first cooling medium is reduced first, so that the heat absorption of the front stage is appropriately increased, thereby sharing the cooling pressure of the rear stage and realizing the redistribution of heat load. On the one hand, it can effectively reduce the cooling consumption of the spray device, and on the other hand, it can avoid the risk of thermal shock. The temperature fluctuation of the copper wire is reduced by staged cooling, reducing the internal stress concentration of the material and reducing the micro-cracks on the surface of the copper wire caused by sudden cooling. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a flowchart of the continuous drawing and densification method for copper wire in Example 1;

[0041] Figure 2 This is a framework diagram of the copper wire continuous drawing densification system in Example 2;

[0042] Figure 3 A schematic diagram of the combined structure of the drawing die and the spraying device;

[0043] Figure 4 for Figure 3 A decomposition diagram of the composite structure at the first angle;

[0044] Figure 5 for Figure 3 A schematic diagram of the decomposition of the composite structure at the second angle;

[0045] Figure 6 A schematic diagram of the drawing die (including a partial sectional view);

[0046] Figure 7 This is a schematic diagram of the distribution plate in the spray device;

[0047] Figure 8 This is a schematic diagram of the mixing process of the first and second cooling media;

[0048] Figure 9 This is a diagram illustrating the transition of the location from off to on.

[0049] Figure 10 for Figure 9 A magnified view of a section at point A in the middle;

[0050] Figure label:

[0051] 1. Drawing die; 2. Spraying device;

[0052] 11. Flow branch; 12. First annular branch; 13. Second annular branch; 14. Auxiliary medium flow channel; 15. Inlet; 16. Outlet; 17. Base; 18. End cap; 19. Inner ring; 110. Outer ring; 111. Stepped surface; 112. Magnetic ring; 21. Flow stop ring; 22. Third annular branch; 23. First hole; 24. Second hole; 25. Distribution plate; 26. Cover. Detailed Implementation

[0053] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0054] Example 1:

[0055] like Figure 1 As shown, a method for densifying copper wire through continuous drawing includes:

[0056] Coolant channels are incorporated into the drawing die;

[0057] During the drawing process, a first cooling medium is introduced into the coolant channel, and the temperature difference of the first cooling medium at the outlet and inlet of the coolant channel is continuously monitored.

[0058] When the temperature difference is less than the set threshold, the temperature of the first cooling medium is reduced, and at the same time, the spray device is turned on at the exit of the drawing die to spray the second cooling medium onto the copper wire moving out of the drawing die.

[0059] The temperature of the second cooling medium is lower than that of the first cooling medium, and the temperature of the first cooling medium is higher than that of the second cooling medium after it decreases.

[0060] In this embodiment, by monitoring the temperature difference between the inlet and outlet of the cooling medium and setting a threshold, the thermal load status of the cooling system can be accurately determined, avoiding energy waste or insufficient cooling in traditional fixed cooling modes. When the temperature difference is lower than the threshold, dual cooling is triggered in conjunction, breaking through the thermal management bottleneck of a single cooling method and ensuring that the copper wire is always within a suitable temperature window during the drawing process. Specifically, the heat generated during the drawing process is absorbed by the mold, suppressing frictional heat and deformation heat sources. When this part of the cooling effect is insufficient, spray cooling directly acts on the surface of the copper wire to eliminate residual heat and prevent softening.

[0061] Under normal operating conditions, cooling is achieved solely through the coolant flow channel, allowing for relatively energy-efficient operation. Under high heat load conditions, dual cooling is implemented. In the dual cooling process, the temperature of the first cooling medium is reduced to appropriately increase the heat absorption of the preceding stage, thereby sharing the cooling pressure of the subsequent stage and redistributing the heat load. This effectively reduces the cooling consumption of the spray device and avoids the risk of thermal shock. The staged cooling reduces the temperature fluctuation of the copper wire, reduces internal stress concentration in the material, and reduces the formation of microcracks on the surface of the copper wire due to sudden cooling.

[0062] In practice, the setting threshold of temperature difference and the determination of the temperature of the first and second cooling media need to be based on the linkage design of thermodynamic principles and process parameters, or the empirical values ​​already used in actual production can be carefully adjusted.

[0063] As a preferred embodiment of the above, the first cooling medium and the second cooling medium are the same medium, and the temperature of the first cooling medium is reduced by mixing with the second cooling medium.

[0064] This optimization method can improve heat exchange efficiency, avoid phase change interference from homogeneous media, prevent heat transfer efficiency decay caused by mixing heterogeneous media, and maintain the stability of heat conduction in the cooling channel. Using the same medium allows for a single medium circulation system, only requiring control of branches with different temperatures, thereby simplifying the cooling medium supply architecture and reducing equipment maintenance costs. The mixing method enables rapid adjustment of the first cooling medium temperature, adapting to dynamic heat load changes in the drawing process.

[0065] During implementation, the first and second cooling media can be deionized water-based corrosion inhibitors. Of course, this is just a conventional choice. Other media that meet the usage requirements under specific environments are also within the scope of protection of this invention.

[0066] As a preferred embodiment of the above, when the temperature difference is less than the set threshold, the action of reducing the temperature of the first cooling medium is performed after 0.1 to 2 seconds, thereby avoiding false triggering caused by instantaneous thermal interference. During the drawing process, sudden fluctuations in local frictional heat, such as copper chips jamming the mold, may cause the temperature difference to drop instantaneously, but in reality, the continuous cooling failure state is not reached. By delaying and filtering instantaneous interference, the triggering action only responds to the continuous thermal load exceeding the limit.

[0067] Example 2

[0068] like Figure 2 As shown, a continuous drawing densification system for copper wire includes:

[0069] The drawing die is provided with a coolant flow channel for the first cooling medium to circulate;

[0070] The temperature monitoring module monitors the temperature difference of the first cooling medium at the outlet and inlet of the coolant flow channel;

[0071] A spraying device is installed at the outlet of the drawing die and is used to spray a second cooling medium onto the copper wire.

[0072] The control module acquires the temperature difference, and when the temperature difference is less than a set threshold, it issues a cooling command for the first cooling medium. This cooling can be achieved by activating a cooling device, such as a heat exchanger, and simultaneously activating a spray device.

[0073] The medium supply module provides a first cooling medium and a second cooling medium, respectively.

[0074] The temperature of the second cooling medium is lower than that of the first cooling medium, and the temperature of the first cooling medium is higher than that of the second cooling medium after it decreases.

[0075] In this embodiment, the first cooling medium and the second cooling medium are made of the same material; the drawing die is also provided with an auxiliary medium flow channel, which is connected to the coolant flow channel; the auxiliary medium flow channel is used to introduce the second cooling medium into the coolant flow channel to reduce the temperature of the first cooling medium in the flow channel.

[0076] As a preferred embodiment, when the temperature difference is less than a set threshold, the cooling command of the first cooling medium is issued after 0.1 to 2 seconds.

[0077] The technical effects achieved in this embodiment are the same as those in Embodiment 1, and will not be repeated here.

[0078] Example 3

[0079] The main system form in this embodiment is the same as that in Embodiment 2, except that the drawing die and spraying device adopt the following structural forms:

[0080] like Figures 3-10 As shown, the coolant flow channel includes at least two flow branches 11. One end of each flow branch 11 is connected by a first annular branch 12, and the other end is connected by a second annular branch 13. The first annular branch 12 and the second annular branch 13 are respectively connected to the inlet 15 and the outlet 16. During implementation, the movement direction of the copper wire is opposite to the setting direction of the inlet 15 and the outlet 16, thereby ensuring that the first cooling medium and the copper wire exchange heat in opposite directions.

[0081] The drawing die 1 is also provided with an auxiliary medium flow channel 14, which is an annular flow channel that is coaxial with and connected to the first annular branch 12, and has an annular open end;

[0082] The spray device 2 has a ring structure and a protruding stop ring 21. The side wall of the stop ring 21 is embedded in the auxiliary medium flow channel 14. The third annular branch 22 inside the spray device 2 is connected to the spray position and the auxiliary medium flow channel 14 through the first hole 23 and the second hole 24 respectively. The flow path direction and number of the first hole 23 and the second hole 24 can be set according to actual needs.

[0083] When the second cooling medium flows into the third annular branch 22, the spray device 2 opens the connection position between the second hole 24 and the auxiliary medium flow channel 14 by moving relative to the drawing die 1; otherwise, the connection position is closed.

[0084] This preferred embodiment provides a partial system structure that enables the first cooling medium to reduce its temperature by mixing with the second cooling medium, as described in Embodiment 1. Through the combination of the drawing die 1 and the spraying device 2, the mixing of the second and first cooling media and the spraying operation can be achieved simultaneously. Specifically, under normal circumstances, the flow of the first cooling medium proceeds normally. When the second cooling medium does not flow into the third annular branch 22, the connection between the second hole 24 and the auxiliary medium flow channel 14 is closed, and the first annular branch 12 is in a relatively closed state.

[0085] When the second cooling medium flows in and causes pressure to be obtained in the third annular branch 22, on the one hand, the third annular branch 22 supplies coolant to the spray position through the first hole 23, and on the other hand, the connection position is opened, and the second cooling medium flowing in through the second hole 24 will mix with the first cooling medium through the auxiliary medium flow channel 14 and the first annular branch 12, thereby achieving the technical effect to be achieved in the above embodiment 1.

[0086] As a preferred embodiment of the above, the drawing die 1 includes a main body, and an inner ring 19 and an outer ring 110 disposed at one end of the main body;

[0087] A first annular branch 12 and an auxiliary medium flow channel 14 are formed between the inner ring body 19 and the outer ring body 110 through a stepped surface 111;

[0088] The second hole 24 in the spray device 2 is set facing the step surface 111. When the spray device 2 is in contact with the step surface 111, the second hole 24 is blocked by the step surface 111 and the connection position is closed.

[0089] This embodiment provides a specific structural form, the main body of which consists of an end cap 18 and a base 17, respectively providing a second annular branch 13 and a flow branch 11. An inner ring body 19 and an outer ring body 110 are fixedly installed with the main body. A coaxial first annular branch 12 and an auxiliary medium flow channel 14 formed in the middle accommodate the open end of one end of the flow branch 11. The spray device 2 is obtained by combining a distribution plate 25 with a flow-stopping ring 21 and a cover 26, forming a third annular branch 22 between them. This split design ensures the manufacturability of the product structure.

[0090] During installation, the flow-stop ring 21 of the spray device 2 is inserted into the auxiliary medium flow channel 14 through the annular open end of the auxiliary medium flow channel 14. The sidewall of the auxiliary medium flow channel 14 is sealed and fitted tightly to the sidewall of the auxiliary medium flow channel 14, and the sealing relationship is required to be unbroken with the movement of the spray device 2 relative to the drawing die 1, thereby preventing leakage of the second cooling medium. After the above installation process is completed, the auxiliary medium flow channel 14 can guide the movement of the spray device 2 through its sidewall, thereby ensuring the stability of its movement and making the opening and closing of the connection position smoother.

[0091] As the optimal way to open the connection position, the second cooling medium flowing out from the second hole 24 applies pressure to the step surface 111, and the spray device 2 moves under the reaction force to open the connection position.

[0092] This method requires no additional power, effectively reducing implementation costs. For example... Figure 8 The diagram shows a schematic representation of the mixing process between the first and second cooling media. Figure 9 The diagram shows the Unicom location switching from off to on.

[0093] Of course, in order to better achieve the above optimization, a limit device and a reset device are provided between the drawing die 1 and the spraying device 2; the limit device is used to limit the movement limit distance of the spraying device 2 relative to the drawing die 1; the reset device applies force to the spraying device 2 relative to the drawing die 1 to reset it when the spraying stops, so as to close the connection position.

[0094] In this preferred embodiment, the stability of the combined structure of the drawing die 1 and the spraying device 2 can be ensured by setting a limiting device, thus preventing separation. Regarding the structure of the limiting device, there are various forms available in the prior art. For example, a mechanical blocking structure can be fixedly set on the drawing die 1, and when the spraying device 2 moves to the limit position, it stops moving by touching the mechanical blocking structure.

[0095] Regarding the reset device, since stepless adjustment of the movement distance is not required in this embodiment, and only switching between closing and opening at a set distance is needed, a magnetic structure can be adopted. For example, magnetic rings 112 are respectively provided on the end faces of the outer ring 110 and the distribution plate 25 facing each other. The magnetic strength is such that the second cooling medium flowing out of the second hole 24 can apply pressure to the step surface 111 to open the connection position. When the pressure is released, the two are attached by magnetic attraction to close the connection position. Of course, this is only an example of the structure of a reset device. Methods such as spring reset are also within the protection scope of this invention.

[0096] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A copper wire continuous drawing densification system characterized by, The application relates to a copper wire drawing device, comprising the following parts: a drawing die provided with a cooling liquid flow channel for flowing a first cooling medium; a temperature monitoring module for monitoring the temperature difference of the first cooling medium at the outlet and the inlet of the cooling liquid flow channel; a spraying device arranged at the outlet of the drawing die for spraying a second cooling medium to the copper wire; a control module for acquiring the temperature difference and issuing a temperature reduction command of the first cooling medium when the temperature difference is less than a set threshold value, and simultaneously starting the spraying device; a medium supply module for respectively supplying the first cooling medium and the second cooling medium; wherein the temperature of the second cooling medium is lower than the temperature of the first cooling medium, and the temperature of the first cooling medium after being reduced is higher than the temperature of the second cooling medium; the cooling liquid flow channel comprises at least two flow channels, one end of each flow channel is connected through a first annular branch, and the other end is connected through a second annular branch, and the first annular branch and the second annular branch are connected to the inlet and the outlet respectively; the drawing die is further provided with an auxiliary medium flow channel, the auxiliary medium flow channel is an annular flow channel coaxial with the first annular branch and connected thereto, and has an annular open end; the spraying device is in a ring structure and protrudes with a flow-stopping ring, the side wall of the flow-stopping ring is embedded in the auxiliary medium flow channel, and a third annular branch in the spraying device is connected to the spraying position and the auxiliary medium flow channel through a first hole and a second hole respectively; when the second cooling medium flows into the third annular branch, the spraying device opens the connection position between the second hole and the auxiliary medium flow channel through movement relative to the drawing die, otherwise the connection position is closed.

2. The copper wire continuous drawing densification system of claim 1, wherein, the first cooling medium and the second cooling medium are of the same material; the auxiliary medium flow channel is used for flowing the second cooling medium into the cooling liquid flow channel to reduce the temperature of the first cooling medium in the flow channel.

3. The copper wire continuous drawing densification system of claim 1, wherein, when the temperature difference is less than the set threshold value, the temperature reduction command of the first cooling medium is issued after 0.1-2 seconds.

4. The copper wire continuous drawing densification system of claim 1, wherein, the drawing die comprises a main body, an inner ring body and an outer ring body arranged at one end of the main body; the inner ring body and the outer ring body form a first annular branch and an auxiliary medium flow channel through a stepped surface; the second hole in the spraying device is arranged towards the stepped surface, and when the spraying device is in contact with the stepped surface, the second hole is blocked by the stepped surface to close the connection position.

5. The copper wire continuous drawing densification system of claim 4, wherein, the second cooling medium flowing out of the second hole presses the stepped surface, and the spraying device moves under the reaction force to open the connection position.

6. The copper wire continuous drawing densification system of claim 4, wherein, a limiting device and a resetting device are arranged between the drawing die and the spraying device; the limiting device is used for limiting the movement limit distance of the spraying device relative to the drawing die; the resetting device exerts a force on the spraying device relative to the drawing die to reset when the spraying is stopped, so as to close the connection position.

7. A method of continuous drawing densification of copper wire using the continuous drawing densification system of any one of claims 1 to 6, characterized in that, the application further relates to a copper wire drawing method, comprising the following steps: flowing the first cooling medium into the cooling liquid flow channel during the drawing process, and continuously monitoring the temperature difference of the first cooling medium at the outlet and the inlet of the cooling liquid flow channel. when the temperature difference is less than a set threshold, the first cooling medium temperature is lowered, and a spraying device at an outlet of the drawing die is opened to spray the second cooling medium to the copper wire moving out of the drawing die; wherein the second cooling medium temperature is lower than the first cooling medium temperature, and the first cooling medium temperature after being lowered is higher than the second cooling medium temperature.

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