Flow balance control method and system for double-bar feeding continuous extrusion of special-shaped copper material

Abstract

The present application relates to non-ferrous metal plastic working technical field, specifically to a flow balance control method and system for double-rod feeding continuous extrusion of special-shaped copper material, drawing a drawing into modeling software for digital processing, establishing a coordinate system for centroid calculation; automatically selecting equal-diameter or unequal-diameter double-rod scheme; adjusting the installation height of a die to make the Y coordinate of the double-rod center coincide with the Y coordinate of the entity centroid to obtain a double-rod feeding position; in cooperation with the double-rod feeding position, designing an asymmetric flow guide system for local flow regulation, and based on flow stability and balance setting, carrying out whole-process process parameter collaborative optimization; using finite element software to simulate metal flow, importing the optimized process parameters into a simulation model to verify the standard, and carrying out on-site debugging and parameter solidification, the method solves the filling problem of large-wall-thickness special-shaped copper material through the "centroid matching + die flow guide + process collaboration" three-in-one technical scheme, significantly improves product quality, material utilization and production efficiency.

Description

Technical Field

[0001] This invention relates to the field of non-ferrous metal plastic processing technology, and in particular to a flow balance control method and system for continuous extrusion of irregularly shaped copper materials using a twin-bar feeder. Background Technology

[0002] Continuous extrusion technology is an advanced copper processing technique with advantages such as short process flow, high material utilization, and good product performance. It is widely used in fields such as wires and cables, busbars, and electrical connectors. With the rapid development of industries such as new energy vehicles and high-voltage power transmission and transformation, the demand for copper materials with complex cross-sections and large wall thicknesses has increased dramatically.

[0003] To increase production capacity, the industry generally adopts twin-bar feeding continuous extrusion technology, but existing continuous extrusion technology has the following unresolved pain points: Extremely low flow balance accuracy: Traditional methods rely entirely on worker experience to adjust the relative positions of the two rods, lacking quantitative design standards. The deviation between the flow center and the profile centroid typically exceeds 2mm, leading to severe flow deviation. This manifests as incomplete filling and dimensional errors on one side, while the other side exhibits excessive flash, resulting in significant material waste.

[0004] Products with large wall thickness differences cannot be produced: For irregularly shaped copper materials with a wall thickness ratio greater than 5:1, the centroid offset of the cross section usually exceeds the adjustable range of the double rod equal diameter feed. The existing equal diameter double rod solution cannot achieve flow balance at all, and can only adopt the costly and inefficient milling processing method.

[0005] Long design cycle and high trial molding cost: There is no standardized design process. Each new product needs to be repeatedly tested 3-5 times. The cost of each trial molding exceeds 20,000 yuan. The design cycle is as long as 1-2 months, which seriously affects the market response speed.

[0006] Ignoring vertical alignment: Focusing only on horizontal flow balance and completely ignoring the alignment of the vertical centroid with the center of the double rods leads to uneven wall thickness and bending deformation of the profile, requiring additional straightening processes and increasing production costs.

[0007] The flow guiding system is disconnected from the feeding system: the design of the flow guiding cavity and the working belt is not optimized in coordination with the dual rod feeding position. Even if the dual rod position is correct, uneven wall thickness and folding defects will occur due to the difference in local flow resistance.

[0008] The disconnect between process parameters and flow balance: Process parameters are treated as independent variables and are not optimized in conjunction with the twin-bar feed position and die design. Fluctuations in parameters such as temperature, pressure, and speed directly lead to flow imbalance, and the industry lacks process parameter control standards for flow balance. Summary of the Invention

[0009] The purpose of this invention is to provide a flow balance control method and system for continuous extrusion of irregularly shaped copper materials using a dual-bar feeding system, aiming to solve the filling problem of copper materials with large wall thickness and different shapes, and improve product quality, material utilization and production efficiency.

[0010] To achieve the above objectives, in a first aspect, the present invention provides a flow balance control method for continuous extrusion of irregularly shaped copper materials using a dual-bar feeder, comprising the following steps: Import CAD drawings into 3D modeling software for digital processing, and establish a unified coordinate system for centroid calculation. Based on the centroid offset and equipment parameters, the system automatically selects a double-bar scheme with equal or unequal diameters. Adjust the vertical installation height of the mold so that the Y coordinate of the center of the double rods coincides with the Y coordinate of the centroid of the solid, and obtain the feeding position of the double rods; In coordination with the dual-bar feeding position, an asymmetric flow guiding system is designed to adjust the local flow rate, and the process parameters of the entire process are optimized in a coordinated manner based on the stable and balanced flow rate setting. The finite element method (FEM) software was used to simulate metal flow. The optimized process parameters were imported into the simulation model to verify the standard, and on-site debugging and parameter solidification were carried out.

[0011] The required accuracy for the centroid calculation is as follows: Total cross-sectional area A: ±0.1 mm²; Solid centroid X-coordinate Xc: ±0.05mm; Solid centroid Y-coordinate Yc: ±0.05mm; Maximum wall thickness Tmax, minimum wall thickness Tmin, and wall thickness ratio K, where K = Tmax / Tmin; when the wall thickness ratio K > 5, a dual-rod feeding scheme with unequal diameters is selected.

[0012] The deviation between the Y-coordinate of the center of the two rods and the Y-coordinate of the centroid of the solid shall not exceed ±0.2mm.

[0013] The collaborative optimization of process parameters throughout the entire process includes temperature parameter control, speed and pressure parameter control, and parameter differentiation settings for products with different wall thickness ratios.

[0014] Secondly, the present invention also provides a flow balance control system for continuous extrusion of shaped copper materials using a dual-bar feeder, which is applied to the flow balance control method for continuous extrusion of shaped copper materials using a dual-bar feeder as described in the first aspect above.

[0015] The present invention discloses a flow balance control method for continuous extrusion of irregularly shaped copper materials using a dual-rod feeding system. This method involves importing CAD drawings into 3D modeling software for digital processing, establishing a unified coordinate system for centroid calculation, automatically selecting a dual-rod scheme with equal or unequal diameters based on centroid offset and equipment parameters, adjusting the vertical installation height of the mold to ensure the Y-coordinate of the dual-rod center coincides with the Y-coordinate of the solid centroid, thus obtaining the dual-rod feeding position, and designing an asymmetric flow guiding system for local flow regulation in conjunction with the dual-rod feeding position. Based on a stable and balanced flow setting, the method also optimizes the entire process parameters collaboratively. Finally, finite element method software is used to simulate metal flow, importing the optimized process parameters into the simulation model for verification, and performing on-site debugging and parameter solidification. This method, through a three-in-one technical solution of "centroid matching + mold flow guiding + process collaboration," solves the filling problem of copper materials with large wall thicknesses and significant improvements in product quality, material utilization, and production efficiency. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0017] Figure 1 This is a flowchart of the flow balance control method for continuous extrusion of irregularly shaped copper materials using a dual-bar feeding system provided by the present invention. Detailed Implementation

[0018] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0019] Please see Figure 1 In a first aspect, the present invention provides a flow balance control method for continuous extrusion of irregularly shaped copper materials using a dual-bar feeder, comprising the following steps: S1 imports CAD drawings into 3D modeling software for digital processing and establishes a unified coordinate system for centroid calculation. In this embodiment of the invention, CAD drawings are imported into 3D modeling software, all annotations and auxiliary lines are deleted, and only the outline of the solid section is retained. A single closed solid region is created using the region command, ensuring no overlap, no gaps, and no redundant line segments. A unified coordinate system is established: with the lower left corner of the profile section as the origin (0,0), the X-axis is horizontal to the right, and the Y-axis is vertically upward. The following parameters are accurately calculated using the mass attribute command, with the following accuracy requirements: Total cross-sectional area A: ±0.1 mm²; Solid centroid X-coordinate Xc: ±0.05mm; Solid centroid Y-coordinate Yc: ±0.05mm; Maximum wall thickness Tmax, minimum wall thickness Tmin, and wall thickness ratio K, where K = Tmax / Tmin; when the wall thickness ratio K > 5, a dual-rod feeding scheme with unequal diameters is selected.

[0020] S2 automatically selects a double-rod scheme with equal or unequal diameters based on the centroid offset and equipment parameters. In this embodiment of the invention, the feasibility of the equal diameter scheme is determined as follows: When Xc-D / 2≥5mm and Xc+D / 2≤W-5mm (D is the center distance between the two rods of the equipment, and W is the total width of the profile), the equal diameter double rod scheme is adopted.

[0021] Formula for calculating the position of two rods: X1 = Xc - D / 2; X2 = Xc + D / 2; Y1=Y2=Yc; Where X1 and X2 are the X coordinates of the centers of the left and right rods, and Y1 and Y2 are the Y coordinates of the centers of the left and right rods.

[0022] Calculation of unequal diameter schemes: When the equal diameter scheme is not feasible, the unequal diameter two-bar scheme is adopted: First, determine the optimal X position of the two rods, keeping the center distance D constant, so that the two rods are distributed as symmetrically as possible on both sides of the centroid.

[0023] Calculate the diameter ratio based on the flow balance equation: Q1 / Q2=A1 / A2=(D1²) / (D2²)=(Xc-X1) / (X2-Xc); Where Q1 and Q2 are the flow rates of the left and right rods, A1 and A2 are the cross-sectional areas of the left and right rods, and D1 and D2 are the diameters of the left and right rods.

[0024] Choose the standard copper rod diameter that is closest to the calculated value; a diameter error of ≤2% is acceptable.

[0025] S3 Adjust the vertical installation height of the mold so that the Y coordinate of the center of the double rods coincides with the Y coordinate of the centroid of the solid, and obtain the feeding position of the double rods; In this embodiment of the invention, the vertical installation height of the mold is adjusted so that the Y-coordinate of the center of the double rods completely coincides with the Y-coordinate of the centroid of the solid, with a deviation not exceeding ±0.2mm. Precise adjustment is achieved by adding or removing stainless steel shims with a precision of 0.1mm between the mold and the mounting plate.

[0026] S4 works in conjunction with the dual-bar feed position to design an asymmetric flow guiding system for local flow regulation, and optimizes the entire process parameters based on the stable and balanced flow setting. In this embodiment of the invention, the thick-walled side is optimized: the width of the flow guide cavity is increased by 20%-30%, the length is shortened by 10%-15%, and a pre-storage tank with a depth of 2-4 mm and a width equivalent to the wall thickness is designed to reduce flow resistance and increase flow rate.

[0027] Thin-walled side optimization: The width of the flow guide cavity is reduced by 10-15%, the length is increased by 20-30%, and a flow barrier with a height of 1-2mm is designed to increase flow resistance and reduce flow rate.

[0028] Differentiated work belt design: Maximum wall thickness: Working zone length 1.5~2mm; Minimum wall thickness: Working zone length 3.5~4.5mm; At sharp corners: the working belt is shortened by 10-20%; At rounded corners: the working belt is lengthened by 10-15%; All process parameters are set and controlled to ensure stable and balanced flow. Temperature parameter control (affects metal deformation resistance and fluidity)

[0029] Key control points include: The mold must be preheated in sections, with a temperature difference of ≤5℃ between the left and right sides; The extrusion roller is cooled by circulating oil to ensure that the temperature of the two feed troughs is the same. The copper rod is preheated using induction heating to ensure uniform temperature throughout the entire rod.

[0030] Speed ​​and pressure parameter control (affects feed rate and deformation degree)

[0031] Key control points include: The dual rods employ an independent hydraulic clamping system, equipped with closed-loop pressure control; The extrusion rollers are driven by a servo motor to ensure stable rotation speed; The traction machine adopts closed-loop speed control, which is synchronized with the speed of the extrusion wheel in real time.

[0032] Differentiated setting of process parameters for products with different wall thickness ratios: For products with a wall thickness ratio K > 5:1: use the upper limit of extrusion temperature (520 / 550℃) and the lower limit of extrusion speed (6 / 8m / min) to ensure that the thick-walled area is fully filled; for products with a wall thickness ratio K < 5:1: use the lower limit of extrusion temperature (480 / 520℃) and the upper limit of extrusion speed (8 / 12m / min) to improve production efficiency.

[0033] S5 uses finite element software to simulate metal flow, imports optimized process parameters into the simulation model to verify the standard, and performs on-site debugging and parameter solidification.

[0034] In this embodiment of the invention, Deform-3D or Qform finite element software is used to simulate metal flow, and optimized process parameters are imported into the simulation model to verify the standards. The time difference between filling all parts of the mold cavity is ≤0.05s; Speed ​​deviation at each point of profile exit ≤ ±5%; The pressure distribution in the mold cavity is uniform, with no local high-pressure areas (>1000MPa) or low-pressure areas (<500MPa); The dual-bar feeding speed is consistent, with no significant difference in speed. Based on the simulation results, fine-tune the dimensions of the guide cavity, the length of the working zone, and the process parameters. The adjustment amount for each step is: Flow guide cavity size: 0.5~1mm; Working belt length: 0.2~0.3mm; Extrusion temperature: 10℃; Extrusion speed: 1m / min.

[0035] On-site commissioning and parameter solidification: Install the double-rod guide sleeve and mold according to the calculation results, and preheat to the specified temperature.

[0036] Perform a low-speed trial extrusion (3~5m / min), and fine-tune the position of the double rods according to the condition of the flash: Excessive burr on the left and insufficient fill on the right: shift both rods to the right by 0.5mm. Excessive burr on the right side and insufficient fill on the left side: shift the entire double rod to the left by 0.5mm; Excessive flash on the upper side and insufficient filling on the lower side: The entire mold was moved upward by 0.3mm; Gradually increase the extrusion speed to the normal level, measure the wall thickness of each part of the profile, fine-tune the working belt length and process parameters, and when the product dimensional tolerance meets ±0.1mm and there are no defects in 100 meters of continuous production, solidify all process parameters and form a standard operating procedure.

[0037] Secondly, the present invention also provides a flow balance control system for continuous extrusion of shaped copper materials using a dual-bar feeder, which is applied to the flow balance control method for continuous extrusion of shaped copper materials using a dual-bar feeder as described in the first aspect above.

[0038] To better understand this technical solution, the following embodiments are provided for further explanation: Example 1: No. 1 irregular copper material (46×30mm, wall thickness ratio 6.3:1) Cross-sectional parameter calculation: The total cross-sectional area A = 684 mm², centroid coordinates (Xc = 30.2 mm, Yc = 15.8 mm), maximum wall thickness 19 mm, minimum wall thickness 3 mm, and wall thickness ratio 6.3:1 were obtained through CAD calculation.

[0039] Solution evaluation: The center distance between the two rods of the equipment is D=40mm, Xc+D / 2=50.2mm>46mm (total width of the profile), so the equal diameter solution is not feasible, and the unequal diameter solution is adopted.

[0040] Calculation of the position and diameter of the two rods: Take X1=12mm, X2=52mm (center distance 40mm), flow ratio Q1 / Q2=0.835, diameter ratio D1 / D2=0.914, the right rod is φ20mm, and the left rod is a standard rod of φ18mm.

[0041] Vertical alignment: Adjust the mold installation height so that the Y-coordinate of the double rod center is 15.8mm.

[0042] The flow guiding system is designed as follows: the width of the flow guiding cavity on the right side is 2.5 times larger than that on the left side, and a pre-storage trough with a depth of 3 mm and a width of 18 mm is designed; a flow barrier with a height of 1.5 mm is designed at the left inlet; the length of the working belt is designed according to Table 1.

[0043] Table 1. Process Parameter Design:

[0044] Simulation verification: filling time difference 0.03s, outlet speed deviation ±3.2%, pressure distribution uniform, and consistent dual-rod feeding speed.

[0045] Production results: wall thickness tolerance ±0.08mm, no filling defects, 55% reduction in flash weight, 95.2% material utilization rate, and no quality issues after 12 hours of continuous production.

[0046] Example 2: No. 2 irregular copper material (65×38.5mm, wall thickness ratio 5:1) Cross-sectional parameters calculation: Total cross-sectional area A = 2276 mm², centroid coordinates (Xc = 37.5 mm, Yc = 19.2 mm), maximum wall thickness 27.5 mm, minimum wall thickness 5.5 mm, wall thickness ratio 5:1.

[0047] Scheme determination: Xc-D / 2=17.5mm≥5mm, Xc+D / 2=57.5mm≤65mm, adopt the equal diameter double rod scheme.

[0048] Calculation of the positions of the two rods: X1=17.5mm, X2=57.5mm, Y1=Y2=19.2mm, both rods are φ20mm.

[0049] Vertical alignment: Adjust the mold installation height so that the Y coordinate of the double rod center is 19.2mm.

[0050] The flow guiding system design is as follows: the tip of the flow splitter cone is located on the centroid line with a cone angle of 35°; the hollow area corresponds to an appropriately narrowed flow guiding cavity; the working zone length is designed according to Table 2.

[0051] Table 2 Process Parameter Design:

[0052] Simulation verification: filling time difference 0.02s, outlet speed deviation ±2.8%, pressure distribution uniform, and consistent dual-rod feeding speed.

[0053] Production results: wall thickness tolerance ±0.07mm, no folding defects, burr weight reduced by 48%, material utilization rate 95.8%, and no quality problems after 15 hours of continuous production.

[0054] Table 3. Working belt length design for the two embodiments.

[0055] This method, through precise centroid calculation, quantified dual-rod position design, and stable process parameter control, keeps the deviation between the flow center and centroid within ±0.1mm, completely solving the flow deviation problem inherent in empirical methods. The combination of equal and unequal diameters can solve the filling problem of irregularly shaped copper materials with wall thickness ratios as high as 10:1, filling the technological gap in continuous extrusion production of products with large wall thickness differences. The standardized design process shortens the new product design cycle from 1-2 months to 1-2 weeks and reduces the number of trial runs from 3-5 to 1-2, significantly reducing trial run costs and ensuring stable wall thickness tolerances. The precision is controlled within ±0.1mm, eliminating defects such as incomplete filling, folds, and cracks. The yield rate has increased from 85% to over 98%, and flash has been reduced by more than 50%. Material utilization has increased from the traditional 85% to 95%, saving more than 100kg of raw materials per ton of product. The extrusion speed has increased from the traditional 5 / 8m / min to 8 / 12m / min. The dual-bar feeding capacity is more than 80% higher than that of the single-bar feeding. The closed-loop control of the entire process parameters extends the continuous production time from the traditional 4 / 6 hours to 8 / 10 hours, reducing the number of downtime adjustments.

[0056] The above-disclosed embodiments are merely preferred embodiments of the flow balance control method and system for continuous extrusion of irregularly shaped copper materials using a dual-bar feeding system, and should not be construed as limiting the scope of this application. Those skilled in the art can understand that implementing all or part of the above embodiments and making equivalent changes in accordance with the claims of this application still fall within the scope of this application.

Claims

1. A flow balance control method for continuous extrusion of irregularly shaped copper materials using a dual-bar feeding system, characterized in that, Includes the following steps: Import CAD drawings into 3D modeling software for digital processing, and establish a unified coordinate system for centroid calculation. Based on the centroid offset and equipment parameters, the system automatically selects a double-bar scheme with equal or unequal diameters. Adjust the vertical installation height of the mold so that the Y coordinate of the center of the double rods coincides with the Y coordinate of the centroid of the solid, and obtain the feeding position of the double rods; In coordination with the dual-bar feeding position, an asymmetric flow guiding system is designed to adjust the local flow rate, and the process parameters of the entire process are optimized in a coordinated manner based on the stable and balanced flow rate setting. The finite element method (FEM) software was used to simulate metal flow. The optimized process parameters were imported into the simulation model to verify the standard, and on-site debugging and parameter solidification were carried out.

2. The flow balance control method for continuous extrusion of irregularly shaped copper materials using a dual-bar feeder as described in claim 1, characterized in that, The required accuracy for centroid calculation is as follows: Total cross-sectional area A: ±0.1 mm²; Solid centroid X-coordinate Xc: ±0.05mm; Solid centroid Y-coordinate Yc: ±0.05mm; Maximum wall thickness Tmax, minimum wall thickness Tmin, and wall thickness ratio K, where K = Tmax / Tmin; when the wall thickness ratio K > 5, a dual-rod feeding scheme with unequal diameters is selected.

3. The flow balance control method for continuous extrusion of irregularly shaped copper materials using a dual-bar feeder as described in claim 1, characterized in that, The deviation between the Y-coordinate of the center of the two rods and the Y-coordinate of the centroid of the solid shall not exceed ±0.2mm.

4. The flow balance control method for continuous extrusion of irregularly shaped copper materials using a dual-bar feeder as described in claim 1, characterized in that, The collaborative optimization of process parameters throughout the entire process includes temperature parameter control, speed and pressure parameter control, and parameter differentiation settings for products with different wall thickness ratios.

5. A flow balance control system for continuous extrusion of shaped copper materials using a dual-bar feeder, applicable to the flow balance control method for continuous extrusion of shaped copper materials using a dual-bar feeder as described in any one of claims 1-4.

Images