A drawing die for multiple drawing of copper clad aluminum bar

Abstract

The utility model discloses a kind of drawing die for drawing copper-clad aluminium bar multiple times, it is related to bimetallic composite material processing die field, including mould core;The mould core is provided with trapezoidal groove structure's drawing groove, and the lower end opening of drawing groove is less than its upper end opening;In drawing groove, inclined surface a, vertical surface b and inclined surface c are sequentially arranged, wherein, the inclined direction of inclined surface c and inclined surface a is opposite, and when copper-clad aluminium bar extends into drawing groove and lower end is attached on second inclined surface a, annular oil channel is formed between copper-clad aluminium bar and the inner wall of drawing groove, and annular oil channel is communicated with oil groove.The utility model adopts the mode of three mould core combinations, so that copper-clad aluminium composite busbar can experience three times plastic deformation and shaping in one drawing process, and overall shrinkage rate can be controlled within 54% or 75%, compared with the mode of multiple drawing of traditional single die, die replacement frequency is reduced by 2 / 3, and processing efficiency is significantly improved.

Description

Technical Field

[0001] This utility model relates to the field of bimetallic composite material processing molds, and in particular to a drawing mold for repeatedly drawing copper-clad aluminum busbars. Background Technology

[0002] The copper-clad aluminum composite busbar is composed of a core aluminum and a cladding copper layer. Its billet is made by horizontal continuous casting direct composite forming technology. After multiple rolling and drawing deformations, a finished copper-clad aluminum composite busbar with a certain size is obtained.

[0003] The processing technology has the following problems: after rolling, it is necessary to change the drawing die 3 to 15 times to draw the product to the required finished size. It has problems such as low processing efficiency, cumbersome operation, high energy consumption in product processing, and the need for multiple intermediate annealing for work hardening.

[0004] Therefore, it is necessary to propose a drawing die for multiple drawing of copper-clad aluminum busbars to solve the above problems. Utility Model Content

[0005] The purpose of this invention is to provide a drawing die for multiple drawing of copper-clad aluminum busbars. Through the three-core drawing die design, the frequency of die replacement is reduced by 2 / 3, the processing efficiency is increased by three times, and the energy consumption is reduced by 50%.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a drawing die for repeatedly drawing copper-clad aluminum busbars, comprising several die cores; The mold core is provided with a trapezoidal groove structure for drawing, and the lower opening of the drawing groove is smaller than its upper opening and allows the copper-clad aluminum busbar to pass through. The drawing groove is provided with an inclined surface a, a vertical surface b and an inclined surface c in sequence, wherein the inclined surface c and the inclined surface a have opposite inclination directions. Several mold cores are combined and used from top to bottom, with the maximum outer diameter decreasing sequentially. An oil groove is provided on the inner wall of the drawing groove between two adjacent die cores; When the copper-clad aluminum busbar extends into the drawing groove and its lower end is attached to the second inclined surface a, an annular oil channel is formed between it and the inner wall of the drawing groove. The annular oil channel is connected to the oil groove.

[0007] Preferably, when several mold cores are used in combination, a mold sleeve with a conical cylindrical structure is fitted on the outside, and the mold cores and the mold sleeve are fixed together by screws; The mold sleeve is provided with an oil outlet and an oil inlet, and the two ends of the oil groove are respectively connected to the oil outlet and the oil inlet.

[0008] Preferably, the mold core is configured as three, and the three mold cores are, from top to bottom, 1# drawing die, 2# drawing die and 3# drawing die.

[0009] Preferably, the lengths of the No. 1 drawing die, No. 2 drawing die and No. 3 drawing die are set within the range of 35 to 60 mm; the distance between adjacent die cores (1) is set within the range of 3 to 10 mm.

[0010] Preferably, the die angles of the No. 1 drawing die, the No. 2 drawing die, and the No. 3 drawing die are all 9°, and the tension angle of the inclined surface c is all 8°.

[0011] Preferably, the length of inclined surface a is 17mm, the length of vertical surface b is 5mm, and the length of inclined surface c is 3mm.

[0012] The technical effects and advantages of this utility model are as follows: (1) This utility model adopts a combination of several mold cores, so that the copper-clad aluminum composite busbar can undergo several plastic deformations and shapings in one drawing process. The overall shrinkage rate can be controlled within 54% or 75%. Compared with the traditional single mold drawing method, the frequency of mold replacement is reduced by 2 / 3, and the processing efficiency is significantly improved by three times. (2) The size of the die core can be flexibly designed according to the finished product requirements. The drawing raw materials of different sizes can vary within a certain range, reducing the inventory of intermediate material specifications and further improving production efficiency. (3) By reducing the number of times the mold is changed, the downtime and energy consumption caused by frequent mold changes are reduced, and energy consumption is significantly reduced; (4) The special structural design of the mold core makes the copper-clad aluminum composite busbar subject to bidirectional pulling force during the drawing process. This bidirectional force distribution helps the copper-clad aluminum composite busbar to deform evenly during the drawing process, thereby improving the quality of the product. (5) Based on the setting of external heating holes and internal heating holes, the copper-clad aluminum busbar can be heated during the drawing process without tempering, and can be drawn multiple times continuously, thereby improving the drawing processing efficiency. (6) The inclined surface c is located in the rectangular frame groove formed in the drawing groove. When heated, the flame is transmitted along the rectangular frame groove, which can evenly heat the lower side of the copper-clad aluminum busbar. (7) This utility model is not only applicable to the drawing of copper-clad aluminum composite busbars, but also to the drawing process of non-ferrous and ferrous metal composite materials such as copper, aluminum, and steel. It has wide applicability and can meet the processing needs of different metal materials. Attached Figure Description

[0013] Figure 1 This is a cross-sectional view of a single mold core in Embodiment 1 of this utility model.

[0014] Figure 2This is a three-dimensional structural diagram of the drawing die used for multiple drawing of copper-clad aluminum busbars in Embodiment 1 of this utility model.

[0015] Figure 3 This is a cross-sectional view of the drawing die used for multiple drawing of copper-clad aluminum busbars in Embodiment 1 of this utility model.

[0016] Figure 4 This is a schematic diagram of the drawing die used for multiple drawing of copper-clad aluminum busbars in Embodiment 2 of this utility model.

[0017] Figure 5 This is a schematic diagram of another perspective of the drawing die used for multiple drawing of copper-clad aluminum busbars in Embodiment 2 of this utility model.

[0018] Figure 6 This is a three-dimensional structural cross-sectional view of the drawing die used for multiple drawing of copper-clad aluminum busbars in Embodiment 2 of this utility model.

[0019] Figure 7 This is a cross-sectional view of the planar structure of the drawing die used for multiple drawing of copper-clad aluminum busbars in Embodiment 2 of this utility model.

[0020] Figure 8 This is a schematic diagram of the structure of the copper-clad aluminum strip pulling mold of this utility model.

[0021] Figure 9 This is a schematic diagram of the external heating hole structure of this utility model.

[0022] Figure 10 This is a schematic diagram of the annular oil passage structure of this utility model.

[0023] Figure 11 This is a schematic diagram of the structure of the annular oil passage of this utility model when used in conjunction with the oil supply system.

[0024] In the diagram: 1. Mold core; 2. Mold sleeve; 3. Drawing groove; 4. Oil outlet; 5. Oil tank; 6. Oil inlet; 7. Circulation pipe; 8. Oil pump; 9. Electric cooling box; 10. Oil tank; 11. Filter box; 101. External heating hole; 102. Internal heating hole; 103. First pair of connecting pipes; 104. Second pair of connecting pipes; 105. Connecting hole; 106. Circular groove; 5. Circular oil passage. Detailed Implementation

[0025] Example 1 This utility model provides, for example Figures 1-3 The image shows a drawing die used for multiple drawing operations on copper-clad aluminum busbars.

[0026] A drawing die is a tool used in metal processing. It applies tensile force to metal materials to achieve plastic deformation, thereby processing the metal materials into industrial products of the desired shape and size. Existing drawing dies typically include the following components: First, the working cone, usually set in a trumpet shape with a gentle angle, serves to guide the wire smoothly into the die hole, reduce stress concentration caused by impact or bending, and prevent the wire from jamming or breaking. It is also the main area where the metal material undergoes plastic deformation during the drawing process. Its cone angle parameter is usually controlled within the range of 55-70 degrees.

[0027] Second, the sizing zone is a key area for ensuring the dimensional accuracy of the material after drawing, and its length directly affects the dimensional accuracy of the product.

[0028] Third, the exit area ensures that the deformed metal material is smoothly discharged from the mold.

[0029] The working principle of drawing dies is based on the plastic deformation of metals. When metal material passes through a tapered die orifice under axial tensile force, plastic deformation occurs, the cross-sectional area decreases, and a continuous product with the same geometry as the die orifice is obtained. The specific process is as follows: 1. Fixing and clamping: Fix one end of the raw material to be drawn (such as metal rod, tube or wire) to the chuck of the drawing machine.

[0030] 2. Tension application: The power system of the drawing machine (such as motor, hydraulic system, etc.) starts to work, generating sufficient tension to make the material pass through the die under the action of tension.

[0031] 3. Deformation through the die: When the material passes through the die, the shape and size of the die hole determine the shape and size of the material after drawing; the material undergoes plastic deformation when passing through the die, and its internal grain structure is also elongated along the drawing direction, thereby changing the material's strength and other properties.

[0032] In this invention, a drawing groove 3 is provided on the mold core 1, which penetrates both the upper and lower surfaces of the mold core 1. The drawing groove 3 is provided with an inclined surface a, a vertical surface b, and an inclined surface c from top to bottom. When it is necessary to draw the copper-clad aluminum composite busbar, the copper-clad aluminum composite busbar is inserted from the inclined surface a. After being guided and squeezed by the inclined surface a, it undergoes plastic deformation. After plastic deformation, the copper-clad aluminum composite busbar passes through the vertical surface b. After passing through the vertical surface b for a certain length, the copper-clad aluminum composite busbar is basically shaped. Finally, the copper-clad aluminum composite busbar is discharged from the inclined surface c. The inclined surfaces a and c have opposite inclination directions, which ensures that the copper-clad aluminum composite busbar can smoothly enter and exit the drawing groove 3.

[0033] In the actual drawing process of copper-clad aluminum composite busbars, if the shrinkage rate of a single drawing of a soft copper-clad aluminum composite busbar exceeds 25%, it is prone to drawing breakage. If the shrinkage rate of a single drawing of a hard copper-clad aluminum composite busbar exceeds 18%, it is also prone to drawing breakage. Therefore, multiple drawing operations are required to finally form the copper-clad aluminum composite busbar. It usually requires 3 to 15 drawing operations with different drawing dies to achieve the required finished size. This process has problems such as low processing efficiency, cumbersome operation, high energy consumption in product processing, and the need for multiple intermediate annealing processes for work hardening.

[0034] Therefore, refer to Figure 2 and Figure 3 As shown in the figure, the present invention is provided with a mold sleeve 2. The interior of the mold sleeve 2 adopts a combination and configuration of three mold cores 1, which reduces the frequency of mold replacement by 2 / 3, increases the processing efficiency by three times, and can significantly reduce energy consumption. Moreover, the size of the drawing material is no longer a single size but can be adjusted according to the arrangement and combination of the mold cores 1. The size of the drawing material can vary within a certain range, reducing the inventory of intermediate material specifications.

[0035] Specifically, the mold sleeve 2 has a conical cylindrical structure, and three mold cores 1 are installed inside the mold sleeve 2. Each mold core 1 is conical in shape and has a drawing groove 3 that penetrates both the upper and lower surfaces. The maximum outer diameter of the three mold cores 1 decreases sequentially. The drawing groove 3 also has an inclined surface a, a vertical surface b, and an inclined surface c sequentially arranged within it. The lower end of the inclined surface c of the upper mold core 1 aligns perfectly with the upper end of the inclined surface a of the lower mold core 1. When the copper-clad aluminum composite busbar extends from the upper end of the drawing groove 3, it first undergoes plastic deformation due to extrusion via the inclined surface a of the upper mold core 1, and then is shaped by the vertical surface b of the upper mold core 1, thus improving the copper-clad aluminum composite... The dimensional accuracy of the busbar is ultimately achieved by exiting through the inclined surface c on the upper mold core 1. When the copper-clad aluminum composite busbar exits from the inclined surface c on the upper mold core 1, it enters the inclined surface a on the middle mold core 1 for secondary extrusion and plastic deformation. In other words, the copper-clad aluminum composite busbar in this invention can undergo three plastic deformation and shaping processes at once, and release the extrusion stress through the inclined surface c. The shrinkage rate in each mold core 1 is controlled within 18% or 25%, and the overall shrinkage rate after passing through three mold cores 1 can be controlled within 54% or 75%. It is also less prone to pull-out breakage. The frequency of mold replacement is reduced by 2 / 3, the processing efficiency is increased by three times, and energy consumption can be significantly reduced.

[0036] It should be noted that the mold core 1 and the mold sleeve 2 can be fixed with screws or other fixing methods, which are common connection methods in the prior art and will not be described in detail here; those skilled in the art can also combine three, four or more mold cores 1 for use according to actual needs.

[0037] Furthermore, this utility model also provides an oil outlet 4 and an oil inlet 6 on the die sleeve 2, and an oil groove 5 on the inner wall of the drawing groove 3. The oil groove 5 is located between two adjacent die cores 1, and the two ends of the oil groove 5 are connected to the oil outlet 4 and the oil inlet 6 respectively. Lubricant can be added to the oil groove 5 through the oil inlet 6 to ensure that there is a smooth transition surface between the copper-clad aluminum composite busbar and the inner wall of the drawing groove 3, and to ensure sufficient lubrication before the copper-clad aluminum composite busbar contacts the die core 1, thereby reducing frictional heat and wear and improving the surface finish of the copper-clad aluminum composite busbar. Since the oil groove 5 is located between two adjacent die cores 1, the lubricant can be blocked in the oil groove 5 after the copper-clad aluminum composite busbar is drawn into the drawing groove 3, and will not leak at once. As the copper-clad aluminum composite busbar is pushed forward, the lubricant is gradually scraped and carried into the space between the copper-clad aluminum composite busbar and the inner wall of the drawing groove 3 by the copper-clad aluminum composite busbar, avoiding the waste caused by excessive use.

[0038] It should be noted that at least one layer of lubricant should be applied to the inner wall of the drawing groove 3 before the copper-clad aluminum composite busbar extends into the drawing groove 3, so as to facilitate lubrication when the copper-clad aluminum composite busbar initially enters the drawing groove 3.

[0039] The lubricant can be a paste-like lubricant based on a combination of soaps and fatty substances, which can be injected into the oil tank 5 at once to supply the drawing die for a longer period of use and reduce the number of replacements.

[0040] As an extension, this invention can also be applied to the drawing process of non-ferrous and ferrous metal composite materials such as copper, aluminum, and steel to improve drawing efficiency.

[0041] In this embodiment, the three-core drawing die is used. Each core 1 corresponds to a drawing die. From top to bottom, they are drawing die #1, drawing die #2, and drawing die #3. The length of each drawing die is set to L, which is kept within the range of 35 to 60 mm. The distance between adjacent cores 1 can be set to d, which is kept within the range of 3 to 10 mm. The length of the die sleeve 2 is set to (3L+2d) mm. The taper of the core 1 and the taper of the die sleeve 2 are set to be the same, which is 4 to 10°.

[0042] Table 1: Table of Die Drawing Parameters

[0043] Based on the information shown in the table above, after the copper-clad aluminum workpiece passes through the head once, the head can pass through three dies at once and enter the clamp for continuous drawing.

[0044] After the first drawing process using drawing die #1, the dimensions are: Width is: Thickness: ; After the second drawing process using drawing die #2, the dimensions are: width Thickness: ; After the third drawing pass using drawing die #3, the dimensions are: width Thickness: ; Based on the above, in this embodiment, when the dimensions of the raw material copper-clad aluminum workpiece are: width 48mm and thickness 10mm, after the first drawing process using drawing die #1, the dimensions are: Width is: mm; thickness is: mm; of which, the diameter of the small end of the mold is 109 mm, the plastic deformation rate in the width direction is 6.25%, and the plastic deformation rate in the thickness direction is 15.00%.

[0045] After the second drawing process using drawing die #2, the dimensions are: width mm, thickness: mm; of which, the diameter of the small end of the mold is 105 mm, the plastic deformation rate in the width direction is 6.67%, and the plastic deformation rate in the thickness direction is 17.65%.

[0046] After the third drawing pass using drawing die #3, the dimensions are: width mm, thickness: mm; of which, the diameter of the small end of the mold is 109 mm, the plastic deformation rate in the width direction is 4.76%, and the plastic deformation rate in the thickness direction is 14.29%.

[0047] In the above embodiments, the mold taper is 6°, the mold angle is 9°, the expansion angle of the outlet (inclined surface c) is 8°, the length of the deformation zone (inclined surface a) is 17mm, the length of the sizing zone (vertical surface b) is 5mm, and the outlet length is 3mm. The lengths of the outlet, deformation zone, and sizing zone are defined along the height direction of the mold core 1.

[0048] Therefore, using 48*10mm copper-clad aluminum as the raw material blank, after one head-making and die-through, it is drawn through three die cores in a single drawing process to achieve plastic deformation and then drawn to a 40*6mm specification.

[0049] In summary, this invention solves the problems of low deformation rate of a single drawing die, complex process flow, and low drawing efficiency caused by matching multiple specifications of products with multiple specifications of dies. It can effectively increase production capacity and reduce production energy consumption. At the same time, it can solve the problem of the drawing force of a single die penetrating from the entire outlet direction to the inlet direction. The drawing force of the No. 2 and No. 3 drawing dies penetrates from both the outlet and inlet directions, which is beneficial to metal deformation and improves product quality. That is, the drawing force acts on the copper-clad aluminum composite busbar not only from the inlet direction of the die, but also from the outlet direction. This bidirectional force distribution helps the copper-clad aluminum composite busbar to deform evenly during the drawing process, thereby improving product quality.

[0050] Example 2 This utility model provides, for example Figures 4-9 The drawing die shown is used for multiple drawing of copper-clad aluminum busbars. It includes a core 1, which is a conical structure with a smaller diameter at the lower end and a larger diameter at the upper end. A drawing groove 3 is provided on the core 1, penetrating its upper and lower surfaces. The inner wall of the drawing groove 3 also has an inclined surface a, a vertical surface b, and an inclined surface c. The inclined surfaces a, b, and c are arranged in groups from top to bottom. Multiple groups of inclined surfaces a, b, and c are distributed along the height direction of the core 1. The interior of the core 1 also includes... There are multiple annular grooves 106, which surround the outer periphery of the drawing groove 3. An inner heating hole 102 is provided on the inclined surface c, and the inner heating hole 102 is connected to the corresponding annular groove 106. The multiple annular grooves 106 are connected to each other through a connecting hole 105. A first pair of connecting pipes 103 and a second pair of connecting pipes 104 are respectively provided on the upper and lower sides of the mold core 1. The first pair of connecting pipes 103 and the second pair of connecting pipes 104 are respectively connected to the corresponding annular grooves 106 above and below.

[0051] During operation, the first pair of connecting pipes 103 are connected to an external flame gun or other flame-generating device, and the second pair of connecting pipes 104 are connected to an exhaust gas treatment device. After the copper-clad aluminum busbar is preheated, it is inserted from above the drawing groove and drawn sequentially through multiple inclined surfaces a and vertical surfaces b. The flame that enters the annular groove 106 through the first pair of connecting pipes 103 will be sprayed onto the outer surface of the copper-clad aluminum busbar from the inclined surface c through the internal heating hole 102, heating the copper-clad aluminum busbar so that it can be drawn into shape in one go without the need for multiple tempering and drawing, thus improving efficiency. Furthermore, due to the special structure inside the mold core 1, it can undergo multiple drawing processes, reducing deformation and the need for tempering and preheating, making it highly practical.

[0052] It should be noted that multiple sets of sequentially distributed inclined surfaces a, vertical surfaces b, and inclined surfaces c can be set in the drawing groove according to actual needs to produce copper-clad aluminum busbars of different sizes.

[0053] For example, when generating copper-clad aluminum busbars with more than three drawing cycles, an external heating hole 101 is provided at the upper end of the mold core 1. The external heating hole 101 is connected to the uppermost annular groove 106 of the mold core 1. The end of the external heating hole 101 away from the annular groove 106 is inclined towards the center of the drawing groove 3. During operation, the copper-clad aluminum busbar heated to a red-hot state is first inserted into the drawing groove 3 from above. The copper-clad aluminum busbar is drawn through the first set of inclined surfaces a, vertical surfaces b, and inclined surfaces c. After being drawn through three sets of inclined surfaces a, vertical surfaces b, and inclined surfaces c, the heat of the copper-clad aluminum busbar decreases, and the drawing difficulty increases significantly. It needs to be tempered to a red-hot state before it can continue to be drawn. However, in this utility model, based on the setting of the external heating hole 101 and the internal heating hole 102, the copper-clad aluminum busbar can be heated during the drawing process without tempering, and it can be drawn multiple times continuously, improving the processing efficiency of drawing.

[0054] Working principle: When the lower end of the copper-clad aluminum busbar just passes through the vertical surface b at the corresponding position, part of the flame is ejected from the inner heating hole 102 to heat the lower side of the copper-clad aluminum busbar; the inclined surface c is located in the rectangular frame groove formed in the drawing groove 3. During heating, the flame is transmitted along the rectangular frame groove, which can evenly heat the lower side of the copper-clad aluminum busbar; another part of the flame is ejected from the outer heating hole 101, and the flame acts on the outer surface of the copper-clad aluminum busbar located outside the drawing groove 3; the two flames heat the section of the copper-clad aluminum busbar that is about to be drawn, ensuring that the copper-clad aluminum busbar can be continuously drawn.

[0055] Example 3 refer to Figure 10 and Figure 11 As shown, when the copper-clad aluminum busbar extends into the drawing groove 3 and its lower end is attached to the second inclined surface a, an annular oil passage 501 is formed between it and the inner wall of the drawing groove 3. The annular oil passage 501 is connected to the oil groove 5. Oil can be supplied to the annular oil channel 501 through an external oil supply system. The oil supply system includes a circulation pipe 7, an oil pump 8, an electric cooling box 9, an oil tank 10, and a filter box 11. The circulation pipe 7 is connected between the corresponding oil outlet 4 and oil inlet 6. The oil pump 8, the electric cooling box 9, the oil tank 10, and the filter box 11 are arranged sequentially on the circulation pipe 7. When the oil pump 8 is started, the oil in the oil tank 10 can be drawn into the annular oil channel 501 to supply oil to the outer surface of the copper-clad aluminum busbar without leakage, thus avoiding waste.

[0056] To ensure better shaping and drawing of the copper-clad aluminum busbar as it moves downwards into the drawing groove 3, an electric cooling box 9 can be used to cool the oil supplied to the annular oil passage 501. When the oil pump 8 is continuously running, the oil enters the annular oil passage 501 sequentially through the electric cooling box 9, the circulation pipe 7, and the oil outlet 4, and then returns to the oil tank 10 sequentially through the oil inlet 6, the circulation pipe 7, and the filter box 11. This achieves a circulating supply of oil, cooling and shaping the copper-clad aluminum busbar that has just passed the inclined surface a and the vertical surface b, reducing the phenomenon of expansion and enlargement of the copper-clad aluminum busbar immediately after drawing.

[0057] Furthermore, the oil is filtered as it passes through filter box 11, ensuring its long-term usability.

[0058] It should be noted that the filter box 11 is a common filter mechanism used for filtering oil on the market, and can use an activated carbon filter element. The electric cooling box 9 is used to cool the oil and is also common on the market. The oil pump 8 is an LK-60-220AC oil pump.

[0059] When the oil supply system is used in conjunction with the drawing die for multiple drawing of copper-clad aluminum busbars in Example 1, the copper-clad aluminum busbars can only be drawn a maximum of three times before tempering is required. When the oil supply system is used in conjunction with the drawing die for multiple drawing of copper-clad aluminum busbars in Example 2, the copper-clad aluminum busbars are reheated during the drawing process, allowing for repeated heating and cooling of the copper-clad aluminum busbars for drawing. This not only enables the copper-clad aluminum busbars to be shaped faster but also improves the drawing efficiency of the copper-clad aluminum busbars.

Claims

1. A drawing die for repeatedly drawing copper-clad aluminum busbars, characterized in that: Includes several mold cores (1); The core (1) is provided with a trapezoidal groove structure drawing groove (3), the lower opening of the drawing groove (3) is smaller than its upper opening and allows the copper-clad aluminum busbar to pass through; The drawing groove (3) is provided with an inclined surface a, a vertical surface b and an inclined surface c in sequence, wherein the inclined surface c and the inclined surface a have opposite inclination directions; Several mold cores (1) are used in combination from top to bottom with their maximum outer diameter decreasing sequentially; An oil groove (5) is provided on the inner wall of the drawing groove (3) between two adjacent mold cores (1); When the copper-clad aluminum busbar extends into the drawing groove (3) and its lower end is attached to the second inclined surface a, an annular oil channel (501) is formed between it and the inner wall of the drawing groove (3). The annular oil channel (501) is connected to the oil groove (5).

2. A drawing die for multiple drawing of copper-clad aluminum busbars according to claim 1, characterized in that: When several mold cores (1) are used in combination, a mold sleeve (2) with a conical cylindrical structure is fitted on the outside, and the mold cores (1) and the mold sleeve (2) are fixed together by screws; The mold sleeve (2) is provided with an oil outlet (4) and an oil inlet (6), and the two ends of the oil groove (5) are respectively connected to the oil outlet (4) and the oil inlet (6).

3. A drawing die for multiple drawing of copper-clad aluminum busbars according to claim 2, characterized in that: The mold core (1) is set to three, and the three mold cores (1) are, from top to bottom, 1# drawing mold, 2# drawing mold and 3# drawing mold.

4. A drawing die for multiple drawing of copper-clad aluminum busbars according to claim 3, characterized in that: The lengths of the No. 1 drawing die, No. 2 drawing die and No. 3 drawing die are set within the range of 35 to 60 mm; the distance between adjacent die cores (1) is set within the range of 3 to 10 mm.

5. A drawing die for multiple drawing of copper-clad aluminum busbars according to claim 4, characterized in that: The die angles of the No. 1 drawing die, No. 2 drawing die, and No. 3 drawing die are all 9°, and the tension angle of the inclined surface c is all 8°.

6. A drawing die for multiple drawing of copper-clad aluminum busbars according to claim 4, characterized in that: The length of inclined surface a is 17mm, the length of vertical surface b is 5mm, and the length of inclined surface c is 3mm.

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