High-precision punch-forging composite process and intelligent trimming method

Abstract

The present application relates to the technical field of aluminum alloy wheel hub manufacturing, and particularly relates to a high-precision impact-forging composite process and intelligent trimming method, which comprises three parts of blank preparation and parameter optimization, multi-stage forging composite treatment and intelligent trimming. By optimizing key processes such as sawing precision, preheating uniformity, forging parameter dynamic adjustment, cooling and cold spinning trajectory planning, the product performance and consistency are significantly improved. The present application can reduce the influence of human operation on quality, reduce energy consumption and material waste, solve the problems of unstable hole edge quality and stress concentration in the traditional process, and is suitable for high-end aluminum alloy wheel hub production, and has strong universality and application value.

Description

Technical Field

[0001] This invention belongs to the field of aluminum alloy wheel manufacturing technology, specifically a high-precision stamping and forging composite process and intelligent dressing method. Background Technology

[0002] Currently, the production process of aluminum alloy wheels plays a crucial role in the automotive manufacturing industry. Its core processes include key steps such as billet sawing, billet preheating, multi-stage forging, punching forging, cooling, and cold spinning. Taking Maisun forged wheels as an example, quality control is emphasized from the source of the aluminum material. Each aluminum bar is inspected by an ultrasonic flaw detector, and an intelligent system automatically intercepts defective products. The aluminum bars are then cut into millimeter-level standard aluminum discs and uniformly quenched in a 480℃ intelligent temperature-controlled heating furnace, laying the foundation for subsequent forging processes.

[0003] In the core manufacturing process of the wheel hub, a combination of forward and reverse forging is used to achieve a balance between strength and lightweight. Specifically, the first forging process uses forward forging to press an aluminum ingot into the mold cavity at a speed of 15mm per second, completing the recombination of metal molecules under thousands of tons of pressure and precisely shaping the initial blank. The second forging process uses reverse forging to form a dense structure of metal material through bidirectional flow. The third forging process further optimizes the grain arrangement, bringing the spoke structure to an ideal state. Subsequently, an 800-ton press is used to finish the blank, and high-pressure water mist is used for rapid cooling to ensure precise locking of the cold working temperature window.

[0004] However, existing technologies still have certain limitations in practical applications. First, during the billet sawing stage, the cutting accuracy of traditional equipment for aluminum bars is greatly affected by tool wear and operating parameters, which may lead to reduced material utilization in subsequent forging processes. Second, during billet preheating, although intelligent temperature-controlled furnaces can provide a uniform heating environment, slight fluctuations in furnace temperature distribution may occur in batch production, thus affecting the consistency of the metal structure. Furthermore, in the 6000T forging stage, due to the relatively low tonnage of the equipment, the stress distribution during billet forming may not be uniform enough, resulting in localized porosity in the internal structure.

[0005] In the 12,000T rough and finish forging stages, although the 10,000-ton press can effectively improve metal density, there is still room for improvement in the matching degree between die design and actual working conditions. Especially in the forming process of complex-shaped wheel hubs, the metal flow within the die cavity may not fully meet the design requirements, potentially leading to micro-cracks or surface defects. In the 1,000T punching forging stage, the accuracy of the punching position and edge quality are easily affected by equipment rigidity and operating parameters, thus limiting the overall performance of the product.

[0006] Cooling and cold spinning, as post-processing steps, also present challenges. During cooling, if the spray angle and flow distribution of the high-pressure water mist are not precisely optimized, it may lead to an excessive temperature gradient on the surface of the blank, thus affecting the grain refinement effect. In the cold spinning stage, although the dual-roller spinning machine can significantly improve the density of the metal fiber structure, the movement trajectory and pressure distribution of the rollers need further optimization to avoid local stress concentration problems.

[0007] In actual large-scale production, the following shortcomings still exist: First, the efficiency of the connection between each process is low, which increases the production cycle; second, the level of equipment automation needs to be improved, and more manual intervention may introduce quality fluctuations; third, for high-end application scenarios, such as high-performance racing cars or new energy vehicle wheels, the precision and consistency of existing processes cannot fully meet the requirements.

[0008] In summary, the existing aluminum alloy wheel manufacturing process still has room for improvement in stages such as billet sawing, preheating, multi-stage forging, punching forging, cooling, and cold spinning. Technological innovation is needed to further improve product quality and production efficiency in order to meet the growing market demand for high-performance wheels. Summary of the Invention

[0009] This invention addresses the shortcomings of existing aluminum alloy wheel manufacturing processes, including billet sawing, preheating, multi-stage forging, punching and forging, cooling, and cold spinning. It proposes a high-precision stamping and forging composite process and an intelligent finishing method. By optimizing parameter matching and equipment design for key processes, this invention reduces the impact of human intervention on product quality, improves the efficiency of connections between processes, and simultaneously reduces energy consumption and material waste during production. The process is highly stable and easy to implement on-site.

[0010] The present invention discloses a high-precision stamping and forging composite process and intelligent dressing method, the specific steps of which are as follows: A high-precision stamping and forging composite process and intelligent dressing method includes the following steps: S1. Billet preparation and parameter optimization: S11) Precision control of billet sawing: A dual-axis linkage CNC cutting machine is adopted, the cutting tool is made of cemented carbide, and the tool wear status is monitored in real time; the cutting speed V is set according to the diameter D of the aluminum rod, and the formula is V=K×D / T, where K is the cutting speed correction coefficient, the value of K ranges from 0.8 to 1.2, and T is the tool life (unit: hours); the perpendicularity error of the end face of the cut aluminum rod is ≤0.05mm, and the surface roughness R is ≤0.05mm. a ≤1.6μm; S12) Improved uniformity of billet preheating: A zoned temperature-controlled heating furnace is adopted, which is divided into an upper heating zone and a lower heating zone. Each heating zone is equipped with an independent temperature control module. By adjusting the power of the upper heating zone and the lower heating zone, the temperature gradient ΔT in the furnace is kept ≤5℃, and the billet is uniformly preheated within the range of 480℃±5℃. S13) Dynamic adjustment of forging parameters: The pressure P1 in the 6000T forging stage and the pressure P2 in the 12000T rough forging stage satisfy the relationship P2=P1×(1+α), where α is the pressure increment coefficient, and the value range is 0.3~0.5. S2, multi-stage forging composite treatment, used for forgings with spoke structures: S21) 6000T forging billet: A conical mold is used, and the mold cavity angle θ1 is set to 15°~20°. The angle β between the metal flow direction in the center area of ​​the billet and the center line of the mold cavity satisfies the relationship β=θ1 / 2, ensuring that β≤10°; the billet is gradually pressed into the mold cavity at a speed of 10mm per second. S22)12000T rough forging: adopts two-way die forging technology. The die cavity is divided into a forward die forging zone and a reverse die forging zone. The metal flow rates V1 and V2 in the two zones satisfy the relationship V1=V2×(1+γ), where γ is the metal flow rate difference coefficient, and the value range is 0.1~0.2. S23) 12000T precision forging: Set the path length of metal flow in the mold cavity to L1, and the length of the spoke structure to L2, satisfying the proportional relationship L1 / L2=1.2~1.5; S24) 1000T punching forging: A floating punch is used, and the gap δ between the punch and the die is set to 0.02mm~0.05mm; the punching position accuracy is controlled by the punch motion trajectory, and the punch motion trajectory equations are X=A×sin(ωt) and Y=B×cos(ωt), where X and Y represent the instantaneous coordinates of the punch in the horizontal plane, t represents time, A represents the amplitude in the X direction, B represents the amplitude in the Y direction, when A = B, the trajectory is a circle, when A ≠ B, the trajectory is an ellipse, and ω is the angular frequency; S3, Intelligent Trimming: S31) Cooling uniformity optimization: A high-pressure water mist spray system is adopted, and the nozzles are arranged in a ring array. The number of nozzles N and the diameter of the aluminum rod D satisfy the relationship N=π×D / d, where d is the nozzle spacing; the surface temperature gradient of the billet ΔT≤10℃; S32) Cold spinning trajectory planning: A dual-wheel synchronous spinning machine is adopted. The roller motion trajectory is controlled by the ellipse equation. The roller motion trajectory equation is x² / a²+y² / b²=1, where a and b are the major and minor axes of the ellipse, respectively.

[0011] Furthermore, in step S11) of controlling the sawing accuracy of the blank, the tool life (unit: hours) T ≥ 50 hours.

[0012] Furthermore, in step S12) improving the uniformity of billet preheating, the temperature gradient ΔT inside the furnace does not exceed 3°C.

[0013] Furthermore, in step S24) 1000T punching forging, the gap δ between the punch and the die is preferably 0.03mm~0.04mm.

[0014] Furthermore, in step S32) cold spinning trajectory planning, the ratio of the major semi-axis a to the minor semi-axis b of the ellipse is 1.2~1.3.

[0015] Furthermore, in step S11) controlling the sawing accuracy of the blank, the correction coefficient K for the cutting speed V is preferably 1.0.

[0016] Furthermore, in step S21) of the 6000T forging billet, the mold cavity angle θ1 is 18°.

[0017] Furthermore, in step S22) 12000T rough forging, the metal flow rate difference coefficient γ is 0.15.

[0018] Furthermore, in step S31) cooling uniformity optimization, the nozzle spacing d ranges from 9mm to 13mm.

[0019] Furthermore, it also includes step S4, online quality monitoring and closed-loop correction: S41) After 6000T forging billet, 12000T rough forging, 12000T precision forging and 1000T punching forging, the three-dimensional point cloud data of the forging is acquired in real time by a laser contour scanner, and compared with the preset CAD model to calculate the local dimensional deviation Δd. S42) When Δd exceeds the preset threshold, the deviation signal is fed back to the dynamic adjustment module for forging parameters in step S13 to automatically correct the pressure increment coefficient α of the next forging. The correction formula is: Where β is the correction gain coefficient, with a value ranging from 0.01 to 0.05; S43) Store the deviation data in the process database for periodic updates of the recommended values ​​for tool life T and pressure increment coefficient α.

[0020] The present invention provides a high-precision stamping and forging composite process and intelligent finishing method. By optimizing the parameter matching and equipment design of key processes such as billet sawing, preheating, multi-stage forging, punching forging, cooling and cold spinning, it achieves efficient connection between processes, reduces the impact of human operation on product quality, and improves product performance and consistency.

[0021] The following beneficial effects can be obtained by using the high-precision stamping and forging composite process and intelligent dressing method of the present invention: The process design is reasonable, the parameter settings are scientific, no additional equipment investment is required, it is safe, reliable and easy to implement on site, meets the manufacturing needs of high-end aluminum alloy wheels, and reduces material consumption; By optimizing the billet sawing and preheating process, the quality fluctuations caused by insufficient equipment precision in traditional processes have been reduced, creating favorable conditions for standardized operations. 3. Through multi-stage forging composite processing, the internal density of the billet and the optimization of grain arrangement are organically combined, which improves the strength and toughness of the product; by adopting intelligent correction technology, through the optimization of cooling uniformity and cold spinning trajectory planning, the surface quality and internal structure performance of the product are significantly improved. 4. By using a floating punch design and elliptical trajectory planning, the problems of unstable punch edge quality and local stress concentration in traditional processes are solved, thus improving the overall performance of the product. It has strong versatility and has certain reference and application value for the improvement of domestic aluminum alloy wheel hub production processes. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating the framework of the high-precision stamping and forging composite process and intelligent dressing method in this invention. Figure 2 This is an overall flowchart of the high-precision stamping and forging composite process and intelligent dressing method in this invention. Detailed Implementation

[0023] The high-precision stamping and forging composite process and intelligent finishing method of the present invention achieves efficient connection between each process by optimizing the parameter matching and equipment design of key processes such as billet sawing, preheating, multi-stage forging, punching forging, cooling and cold spinning, thereby reducing the impact of human operation on product quality.

[0024] The high-precision stamping and forging composite process and intelligent finishing method of the present invention achieves efficient connection between each process by optimizing the parameter matching and equipment design of key processes such as billet sawing, preheating, multi-stage forging, punching forging, cooling and cold spinning, thereby reducing the impact of human operation on product quality.

[0025] S1. In the billet preparation and parameter optimization stage: S11) First, the sawing precision of the billet is controlled. The dual-axis linkage CNC cutting equipment is the core equipment for billet sawing. Its blades are made of cemented carbide and equipped with a blade wear monitoring module. The module monitors the blade wear status in real time. It is installed on the blade clamping device of the cutting equipment and is in direct contact with the blade. It is used to collect data on the wear status of the blade surface in real time and transmit it to the control system. The cutting speed V is set according to the diameter D of the aluminum rod, and the calculation formula is V=K×D / T, where K is the cutting speed correction coefficient, and the value of K ranges from 0.8 to 1.2. In this embodiment, the cutting speed correction coefficient K is preferably 1.0, and T is the tool life (unit: hours), with a tool life (unit: hours) T≥50 hours. During the cutting process, the dual-axis linkage CNC cutting equipment drives the moving platform in the X and Y axes through two sets of servo motors to achieve precise cutting of the aluminum rod. After cutting, the perpendicularity error of the aluminum rod end face is controlled within ≤0.05mm, and the surface roughness Ra≤1.6μm. This structural design ensures stability during the cutting process while avoiding dimensional deviations caused by tool wear. S12) Improved Billet Preheating Uniformity: A zoned temperature-controlled heating furnace is used in the billet preheating uniformity improvement stage. This furnace is divided into upper and lower heating zones. Each heating zone is equipped with an independent temperature control module. This module collects real-time temperature data via temperature sensors and feeds it back to the control system to adjust the heating power. By adjusting the power of the upper and lower heating zones, the temperature gradient ΔT within the furnace is kept ≤5℃, allowing the billet to be uniformly preheated within a range of 480℃±5℃. In this embodiment, the temperature gradient ΔT within the furnace does not exceed 3℃ during the billet preheating uniformity improvement. This zoned temperature control design effectively solves the problem of uneven temperature distribution in traditional heating furnaces and improves the billet preheating quality. S13) Dynamic adjustment of forging parameters: The pressure P1 in the 6000T forging stage and the pressure P2 in the 12000T rough forging stage satisfy the relationship P2=P1×(1+α), where α is the pressure increment coefficient, and the value range is 0.3~0.5.

[0026] S2, multi-stage forging composite treatment, used for forgings with spoke structures: In the multi-stage forging process, the billet undergoes four consecutive processes: 6000T forging, 12000T rough forging, 12000T precision forging, and 1000T punching forging. S21) 6000T Forging Billet: In the 6000T forging billet stage, a conical mold is used. The billet is placed in the conical mold 6 for compaction. The mold cavity angle θ1 is set to 15°~20°. In this embodiment, the mold cavity angle θ1 is preferably 18°. The angle β between the metal flow direction in the central region of the billet and the center line of the mold cavity satisfies the relationship β=θ1 / 2, ensuring that β≤10°. The billet is gradually compacted in the mold cavity at a speed of 10mm per second. During the compaction process, the pressure P1 is provided by the hydraulic system, and the pressure value is dynamically adjusted according to the material characteristics of the billet. S22), 12000T rough forging: After entering the 12000T rough forging stage, a two-way die forging technology is adopted. The die cavity is divided into a forward die forging zone and a reverse die forging zone. The metal flow rates V1 and V2 in the two zones satisfy the relationship V1=V2×(1+γ), where γ is the metal flow rate difference coefficient, and the value of γ ranges from 0.1 to 0.2. In this embodiment, the metal flow rate difference coefficient γ is preferably 0.15. This two-way die forging design allows the billet metal to form a dense structure in the two-way flow, and the spokes begin to take shape. S23), 12000T precision forging: Subsequently, the billet enters the 12000T precision forging stage. The path length of the metal flow in the mold cavity is set to L1, and the length of the spoke structure is set to L2, satisfying the ratio L1 / L2=1.2~1.5 to ensure that the spoke structure reaches the ideal state. S24), 1000T Punching Forging: Finally, a floating punch is used in the 1000T punching forging stage. The gap δ between the floating punch and the die is set to 0.02mm~0.05mm, preferably 0.03mm~0.04mm. The punching position accuracy is controlled by the punch motion trajectory. The equations of the punch motion trajectory are X=A×sin(ωt) and Y=B×cos(ωt), where X and Y represent the instantaneous coordinates of the punch in the horizontal plane, t represents time, A represents the amplitude in the X direction, and B represents the amplitude in the Y direction. When A=B, the trajectory is a circle; when A ≠ B, the trajectory is an ellipse, and ω is the angular frequency. The design of the floating punch significantly improves the quality of the punched edge, avoiding the burrs and cracks common in traditional punching processes.

[0027] S3, Intelligent Trimming: In this embodiment, the intelligent trimming stage includes cooling uniformity optimization and cold spinning trajectory planning as follows: S31) Cooling Uniformity Optimization: In the cooling uniformity optimization process, a high-pressure water mist spray system is adopted, with the nozzles arranged in a ring array. The number of nozzles N and the diameter D of the aluminum rod satisfy the relationship N=π×D / d, where d is the nozzle spacing. The value of d ranges from 9mm to 13mm. The ring array nozzle arrangement ensures that the surface temperature gradient ΔT of the billet is ≤10℃, resulting in a significant grain refinement effect. S32) Cold Spinning Trajectory Planning: In the cold spinning trajectory planning stage, a dual-wheel synchronous spinning machine is used. The roller motion trajectory is controlled by an ellipse equation, which is x² / a² + y² / b² = 1, where a and b are the major and minor axes of the ellipse, respectively, and the ratio of the major axis a to the minor axis b is 1.2 to 1.3. Elliptical trajectory planning makes the roller motion trajectory smoother and avoids the problem of local stress concentration.

[0028] Based on the above embodiments, step S4, online quality monitoring and closed-loop correction are also included: S41) After 6000T forging billet, 12000T rough forging, 12000T precision forging and 1000T punching forging, the three-dimensional point cloud data of the forging is acquired in real time by a laser contour scanner, and compared with the preset CAD model to calculate the local dimensional deviation Δd. S42) When Δd exceeds the preset threshold, the deviation signal is fed back to the dynamic adjustment module for forging parameters in step S13 to automatically correct the pressure increment coefficient α of the next forging. The correction formula is: Where β is the correction gain coefficient, with a value ranging from 0.01 to 0.05; S43) Store the deviation data in the process database for periodic updates of the recommended values ​​for tool life T and pressure increment coefficient α.

[0029] The equipment and process parameters at each stage described above work together to form the complete technical solution of this invention. For example, the dual-axis linkage CNC cutting equipment and the zoned temperature-controlled heating furnace are seamlessly connected through an automated control system, ensuring the continuity of the billet from sawing to preheating. The design of the conical die and floating punch reflects the synergistic effect between the multi-stage forging and punching forging processes, ensuring the uniformity of stress distribution during the billet forming process. The combination of the high-pressure water mist spraying system and the dual-wheel synchronous spinning machine further improves the surface quality and internal microstructure of the product.

[0030] The specific embodiments of this invention achieve high precision and intelligent operation in the aluminum alloy wheel hub production process by optimizing the equipment structure and process parameters of each step. The connection relationships, positional relationships, and mutual cooperation relationships between various equipment and components are clear and well-defined, ensuring the stability and operability of the process flow.

Claims

1. A high-precision stamping and forging composite process and intelligent dressing method, characterized in that, Includes the following steps: S1. Billet preparation and parameter optimization: S11) Precision control of billet sawing: A dual-axis linkage CNC cutting machine is adopted, the cutting tool is made of cemented carbide, and the tool wear status is monitored in real time; the cutting speed V is set according to the diameter D of the aluminum rod, and the formula is V=K×D / T, where K is the cutting speed correction coefficient, the value of K ranges from 0.8 to 1.2, and T is the tool life (unit: hours); the perpendicularity error of the end face of the cut aluminum rod is ≤0.05mm, and the surface roughness R is ≤0.05mm. a ≤1.6μm; S12) Improved uniformity of billet preheating: A zoned temperature-controlled heating furnace is adopted, which is divided into an upper heating zone and a lower heating zone. Each heating zone is equipped with an independent temperature control module. By adjusting the power of the upper heating zone and the lower heating zone, the temperature gradient ΔT in the furnace is kept ≤5℃, and the billet is uniformly preheated within the range of 480℃±5℃. S13) Dynamic adjustment of forging parameters: The pressure P1 in the 6000T forging stage and the pressure P2 in the 12000T rough forging stage satisfy the relationship P2=P1×(1+α), where α is the pressure increment coefficient, and the value range is 0.3~0.

5. S2, multi-stage forging composite treatment, used for forgings with spoke structures: S21) 6000T forging billet: A conical mold is used, and the mold cavity angle θ1 is set to 15°~20°. The angle β between the metal flow direction in the center area of ​​the billet and the center line of the mold cavity satisfies the relationship β=θ1 / 2, ensuring that β≤10°; the billet is gradually pressed into the mold cavity at a speed of 10mm per second. S22)12000T rough forging: adopts two-way die forging technology. The die cavity is divided into a forward die forging zone and a reverse die forging zone. The metal flow rates V1 and V2 in the two zones satisfy the relationship V1=V2×(1+γ), where γ is the metal flow rate difference coefficient, and the value range is 0.1~0.

2. S23) 12000T precision forging: Set the path length of metal flow in the mold cavity to L1, and the length of the spoke structure to L2, satisfying the proportional relationship L1 / L2=1.2~1.5; S24) 1000T punching forging: A floating punch is used, and the gap δ between the punch and the die is set to 0.02mm~0.05mm; the punching position accuracy is controlled by the punch motion trajectory, and the punch motion trajectory equations are X=A×sin(ωt) and Y=B×cos(ωt), where X and Y represent the instantaneous coordinates of the punch in the horizontal plane, t represents time, A represents the amplitude in the X direction, B represents the amplitude in the Y direction, when A = B, the trajectory is a circle, when A ≠ B, the trajectory is an ellipse, and ω is the angular frequency; S3, Intelligent Trimming: S31) Cooling uniformity optimization: A high-pressure water mist spray system is adopted, and the nozzles are arranged in a ring array. The number of nozzles N and the diameter of the aluminum rod D satisfy the relationship N=π×D / d, where d is the nozzle spacing; the surface temperature gradient of the billet ΔT≤10℃; S32) Cold spinning trajectory planning: A dual-wheel synchronous spinning machine is adopted. The roller motion trajectory is controlled by the ellipse equation. The roller motion trajectory equation is x² / a²+y² / b²=1, where a and b are the major and minor axes of the ellipse, respectively.

2. The high-precision stamping and forging composite process and intelligent dressing method according to claim 1, characterized in that, In step S11), the sawing accuracy control of the blank is such that the tool life (unit: hours) T ≥ 50 hours.

3. The high-precision stamping and forging composite process and intelligent dressing method according to claim 1, characterized in that, In step S12) improving the uniformity of billet preheating, the temperature gradient ΔT inside the furnace shall not exceed 3℃.

4. The high-precision stamping and forging composite process and intelligent dressing method according to claim 1, characterized in that, In step S24) 1000T punching forging, the gap δ between the punch and the die is preferably 0.03mm~0.04mm.

5. The high-precision stamping and forging composite process and intelligent dressing method according to claim 1, characterized in that, In step S32) cold spinning trajectory planning, the ratio of the major semi-axis a to the minor semi-axis b of the ellipse is 1.2~1.

3.

6. The high-precision stamping and forging composite process and intelligent dressing method according to claim 1, characterized in that, In step S11), the correction coefficient K for the cutting speed V is preferably 1.0, which is used to control the cutting accuracy of the blank.

7. The high-precision stamping and forging composite process and intelligent dressing method according to claim 1, characterized in that, In step S21) of the 6000T forging billet, the mold cavity angle θ1 is 18°.

8. The high-precision stamping and forging composite process and intelligent dressing method according to claim 1, characterized in that, In step S22) 12000T rough forging, the metal flow rate difference coefficient γ is 0.

15.

9. The high-precision stamping and forging composite process and intelligent dressing method according to claim 1, characterized in that, In step S31) Cooling uniformity optimization, the nozzle spacing d ranges from 9mm to 13mm.

10. The high-precision stamping and forging composite process and intelligent dressing method according to claim 1, characterized in that, It also includes step S4, online quality monitoring and closed-loop correction: S41) After 6000T forging billet, 12000T rough forging, 12000T precision forging and 1000T punching forging, the three-dimensional point cloud data of the forging is acquired in real time by a laser contour scanner, and compared with the preset CAD model to calculate the local dimensional deviation Δd. S42) When Δd exceeds the preset threshold, the deviation signal is fed back to the dynamic adjustment module for forging parameters in step S13 to automatically correct the pressure increment coefficient α of the next forging. The correction formula is: Where β is the correction gain coefficient, with a value ranging from 0.01 to 0.05; S43) Store the deviation data in the process database for periodic updates of the recommended values ​​for tool life T and pressure increment coefficient α.

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