A high-precision aluminum profile hot extrusion forming and straightening collaborative control method

Abstract

The application discloses a high-precision aluminum profile hot extrusion forming and straightening collaborative control method and relates to the aluminum profile processing technical field.The method comprises the following steps: S1, constructing an extrusion die and an extrusion-straightening collaborative process model based on a profile three-dimensional model; S2, monitoring the extrusion force and the discharging temperature in real time during the extrusion, and dynamically adjusting the extrusion speed and the online cooling intensity; S3, before the profile straightening, acquiring an initial shape deviation through online detection, and adaptively calculating optimal stretching straightening parameters; and S4, detecting after the straightening, and storing the whole process data into a database to optimize the model.The application further relates to an extrusion die for realizing the method.The application reduces defects from the source and realizes adaptive correction through the collaborative control of the extrusion and straightening processes, significantly improves the size and shape precision of the aluminum profile, enhances the production stability, and reduces the waste product rate.

Description

Technical Field

[0001] This invention relates to the field of aluminum profile processing technology, specifically to a manufacturing method for improving the dimensional and shape accuracy of aluminum profiles by synergistically controlling extrusion process parameters and online straightening process parameters. Background Technology

[0002] Aluminum profiles are widely used in construction, transportation, electronics, and other fields due to their advantages such as lightweight, high strength, and corrosion resistance. Hot extrusion is the main process for producing aluminum profiles. However, during the extrusion process, various defects can easily occur due to improper die design, improper setting of extrusion process parameters (such as temperature and speed), and poor control of the cooling and straightening process after extrusion.

[0003] Based on existing technology, common drawbacks include: 1) Dimensional accuracy defects: such as twisting, flaring / joining, thickness difference, flatness, etc. These defects mainly stem from uneven metal flow within the mold cavity, mold elastic deformation, and uneven cooling after demolding.

[0004] 2) Surface and microstructure defects: such as streaks, poor welding, coarse grain rings, etc. These defects are closely related to the quality of the ingot, the condition of the die working zone, extrusion temperature and speed.

[0005] Traditional production methods typically treat extrusion molding and subsequent stretching and straightening as two separate processes. The extrusion process focuses primarily on profile forming, while dimensional and shape correction is entirely dependent on the stretching and straightening process. This approach has significant drawbacks: 1) Limited correction capability: For severe twisting, bending and other defects generated during the extrusion process, it is difficult to completely eliminate them by simply relying on stretching and straightening, or it may require a very large amount of stretching, which may lead to a decrease in the mechanical properties of the profile or the generation of new defects (such as orange peel).

[0006] 2) Unstable precision: Due to the inherent instability of the extrusion process, the initial state of the profiles entering the straightening process fluctuates greatly, making it difficult to guarantee the dimensional and shape precision of the final product.

[0007] 3) Lack of coordination: There is no effective linkage and feedback between the extrusion parameters and the straightening parameters, making it impossible to achieve optimized control of the entire process.

[0008] Therefore, there is an urgent need for a method that can coordinate the extrusion molding and straightening processes to reduce defects at the source and achieve high-precision online correction in order to solve the above-mentioned technical problems. Summary of the Invention

[0009] To address the aforementioned problems, this invention provides a high-precision method for the coordinated control of hot extrusion forming and straightening of aluminum profiles.

[0010] Specifically, it includes the following steps: S1 analyzes the cross-sectional characteristics of the target aluminum profile based on a three-dimensional digital model, and constructs an initial digital model of the extrusion die and an extrusion-straightening collaborative process model; the extrusion-straightening collaborative process model defines the extrusion temperature (T). ex ), extrusion speed (V) ex ), online cooling intensity (C) on The tensile ratio (ε) and tensile speed (V) of the tension leveling machine st The initial mapping relationship between the straightening roll reduction (δ) and the straightening roll reduction (δ).

[0011] During the extrusion process, S2 applies gradient heating to the ingot, ensuring that the temperature at the front end of the ingot is higher than that at the rear end, while controlling the temperature of the extrusion cylinder to be lower than that of the ingot; it also monitors the extrusion pressure (P) and the discharge temperature (T) in real time. out ), and dynamically adjust the extrusion speed (V) based on monitoring data. ex ) and online cooling intensity (C on ).

[0012] Before the profiles enter the tension straightening machine, S3 uses an online detection system to scan the initial curvature and torsion of the profiles to obtain initial shape deviation data (D). initial The parameters are input into the collaborative process model, and the stretching straightening machine straightens the profile according to the calculated optimal parameters.

[0013] S4 performs final accuracy testing on the straightened profile and stores the initial shape deviation data, final shape deviation data, and corresponding extrusion and straightening process parameters of the entire production process as a set of data in the process database for optimizing the collaborative process model.

[0014] Specifically, in step S2, the dynamic adjustment of the online cooling intensity (C) on Specifically, it includes: For aluminum alloy profiles that are prone to developing coarse grain rings, the ingot heating temperature should be controlled within the range of 480-500℃, and the corresponding extrusion speed should be matched.

[0015] For flat or hollow profiles, non-contact cooling methods such as air cooling or mist cooling are used to prevent black spots from forming on the profile surface.

[0016] Specifically, step S2 also includes: The system monitors fluctuations in extrusion pressure (P) in real time and automatically fine-tunes the extrusion speed (V) when it detects sawtooth-like pressure fluctuations that indicate the formation of bite marks or stop marks. ex This is to restore the smoothness of metal flow.

[0017] During the extrusion process, nitrogen gas is sprayed into the exit of the die working zone for protection to prevent oxidation of the working zone surface, thereby reducing the generation of pits and burrs.

[0018] Specifically, step S2 further includes controlling the dimensional fit gap between the extrusion cylinder and the extrusion pad to be between 0.2 mm and 0.5 mm, so as to prevent air from being drawn into the ingot during the extrusion process and forming bubbles or peeling defects.

[0019] The length of the extrusion residue should be controlled to be no less than 10% of the ingot diameter to ensure that oxides and impurities on the surface of the ingot are trapped in the residue and prevented from flowing into the product to form oxide streaks or extrusion tails.

[0020] Specifically, in step S3, the adaptive calculation of the optimal tension straightening parameters includes: Based on the alloy properties and profile condition, a critical elongation threshold is set. Under the premise of ensuring the elimination of unevenness, the actual elongation is controlled to be lower than the threshold to prevent orange peel defects from forming on the profile surface.

[0021] When the initial shape deviation data (D) initial When the twisting is spiral, the front and rear clamps of the tensioning machine are controlled to generate a relative rotation angle, and an axial tensile force is applied for correction.

[0022] Specifically, the actual stretching rate is controlled within the range of -1.5% to +0.5% of the optimal stretching and straightening parameters.

[0023] Specifically, step S3 also includes: for channel or I-shaped profiles, dynamically adjusting the lateral auxiliary device of the stretching machine or the roll gap of the subsequent roller straightener according to the flaring or closing trend after demolding.

[0024] An extrusion die for achieving a method of coordinated control of high-precision aluminum profile hot extrusion forming and straightening.

[0025] Specifically, this includes a mold working strip, the length of which is designed differently based on the predicted metal flow rate. The working strip length is increased in areas with high metal flow rate, and the working strip length is decreased or a flow-promoting angle is set in areas with low metal flow rate.

[0026] Specifically, the cutting edge of the mold working belt is sharp, and the surface of the working belt is uniformly nitrided.

[0027] Specifically, the extrusion die is a flow-dividing combination die. For hollow profiles, the welding cavity structure of the flow-dividing combination die is optimized, and the flow-dividing ratio and welding chamber depth are adjusted to ensure complete welding of the metal flow. The flow-dividing ratio is in the range of 2.5 to 4.0 to ensure sufficient aluminum supply in the welding cavity and prevent poor welding.

[0028] Specifically, the diameter of the diversion hole and the outer circle of the extruded profile in the diversion combination mold is smaller than the inner diameter of the extrusion cylinder, and the single-sided allowance is at least 13mm, so as to prevent the surface metal of the ingot from being rolled into the product and forming impurity defects.

[0029] It has the following beneficial effects: (1) By coordinating the extrusion and straightening processes, this invention can not only reduce defects at the source by optimizing process parameters during the extrusion stage, but also perform adaptive correction based on the real-time status of the profile during the straightening stage, which significantly improves the final dimensional accuracy and shape accuracy of the aluminum profile.

[0030] (2) The dynamic optimization control of the extrusion process of the present invention ensures the stability of the output material quality, provides good initial conditions for the subsequent straightening process, and greatly enhances the stability of the entire production process.

[0031] (3) By introducing online detection, feedback control and model self-learning mechanism, this invention realizes intelligent and closed-loop control of the production process, reduces the dependence on human experience, and can continuously optimize the process.

[0032] (4) The effective collaborative control of the present invention can avoid the straightening process from being unable to correct due to excessive extrusion defects, or the profile performance decline and surface defects (such as orange peel) caused by excessive stretching, thereby effectively reducing the scrap rate. Detailed Implementation

[0033] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0034] To provide a clearer understanding of the technical features, objectives, and beneficial effects of this invention, the technical solutions of this invention are selected and described in detail below. Obviously, the described embodiments are only a portion of the embodiments of this invention, not all of them, and should not be construed as limiting the scope of implementation of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this invention.

[0035] Example 1 This embodiment provides a high-precision method for the coordinated control of hot extrusion forming and straightening of aluminum profiles.

[0036] The high-precision aluminum profile hot extrusion forming and straightening coordinated control method described in this embodiment includes the following steps: S1: Based on the three-dimensional digital model of the target aluminum profile, analyze its cross-sectional characteristics, and construct the initial digital model of the extrusion die and the extrusion-straightening collaborative process model. S1.1: Obtain a three-dimensional digital model of the target aluminum profile and analyze its cross-sectional characteristics to identify key areas such as thin-walled, thick-walled, and cantilevered sections that are prone to uneven metal flow.

[0037] S1.2: Based on the cross-sectional features, establish an initial digital model of the extrusion die, and pre-determine the die working zone length distribution and the flow guide cavity structure.

[0038] S1.3: Construct an initial collaborative control model for extrusion process parameters and straightening process parameters. This model defines the extrusion temperature (T... ex ), extrusion speed (V) ex ), online cooling intensity (C) on The tensile ratio (ε) and tensile speed (V) of the tension leveling machine st) The initial mapping relationship between the straightening roll reduction (δ) and the straightening roll reduction.

[0039] S2: During the extrusion process, the extrusion pressure (P) and discharge temperature (T) are monitored in real time. out ), and dynamically adjust the extrusion speed (V) based on monitoring data. ex ) and online cooling intensity (C on) ; S2.1: Based on the initial collaborative control model, set the initial process parameters for the extruder, heating furnace, and online cooling device.

[0040] S2.2: During the extrusion process, monitor the extrusion pressure (P) and discharge temperature (T) in real time. out ).

[0041] S2.3: The monitored extrusion pressure (P) and discharge temperature (T) out The extrusion speed (V) is compared with the preset target value, and the extrusion speed is dynamically fine-tuned through the feedback controller. ex ) and online cooling intensity (C on This is to ensure the stability of metal flow.

[0042] S3: Before the profile enters the tension straightening machine, the initial shape deviation data (D) of the profile is obtained through an online detection system. initial The parameters are input into the collaborative process model to adaptively calculate the optimal stretching and straightening parameters. S3.1: Before the profile enters the tension straightening machine, the initial curvature and torsion of the profile are scanned by an online vision inspection system to obtain initial shape deviation data (D). initial ).

[0043] S3.2: Transfer the initial shape deviation data (D) initial The input is fed into the cooperative control model, which adaptively calculates the optimal stretching ratio (ε) and stretching speed (V) based on the type and magnitude of the deviation.st ) and the amount of pressure applied to each straightening roller (δ).

[0044] S3.3: The tension straightening machine straightens the profile according to the calculated optimal parameters.

[0045] S4: Perform final precision testing on the straightened profile, and store the process parameters and test results of the entire production process into the process database for optimizing the collaborative process model.

[0046] S4.1: Perform final accuracy testing on the straightened profile to obtain final shape deviation data (Dfinal).

[0047] S4.2: (D) initial) (D) final The data, along with the corresponding extrusion and straightening process parameters, is stored in the process database as a set of data.

[0048] S4.3: Utilize machine learning algorithms to periodically train the data in the process database, optimize the extrusion-straightening collaborative process model, and continuously improve its prediction and control accuracy.

[0049] In this embodiment, in step S2, gradient heating is applied to the ingot so that the temperature at the front end of the ingot is higher than that at the rear end, and the temperature of the extrusion cylinder is controlled to be lower than that of the ingot.

[0050] In this embodiment, in step S2, the dynamic adjustment of the online cooling intensity (C) on Specifically, it includes: For aluminum alloy profiles that are prone to producing coarse grain rings, the ingot heating temperature should be controlled within the range of 480-500℃, and the corresponding extrusion speed should be matched accordingly. For flat or hollow profiles, non-contact cooling methods such as air cooling or mist cooling are used to prevent black spots from forming on the profile surface.

[0051] In this embodiment, step S2 further includes: The system monitors fluctuations in extrusion pressure (P) in real time and automatically fine-tunes the extrusion speed (V) when it detects sawtooth-like pressure fluctuations that indicate the formation of bite marks or stop marks. ex To restore the smoothness of metal flow; During the extrusion process, nitrogen gas is sprayed into the exit of the die working zone for protection to prevent oxidation of the working zone surface, thereby reducing the generation of pits and burrs.

[0052] In this embodiment, step S2 further includes: The dimensional clearance between the extrusion cylinder and the extrusion pad is controlled between 0.2mm and 0.5mm to prevent air from being drawn into the ingot during the extrusion process, forming bubbles or peeling defects. The length of the extrusion residue should be controlled to be no less than 10% of the ingot diameter to ensure that oxides and impurities on the surface of the ingot are trapped in the residue and prevented from flowing into the product to form oxide streaks or extrusion tails.

[0053] In this embodiment, step S3, the adaptive calculation of the optimal tension straightening parameters specifically includes: Based on the alloy properties and profile condition, a critical elongation threshold is set. Under the premise of ensuring the elimination of unevenness, the actual elongation is controlled to be lower than the threshold to prevent orange peel defects from forming on the profile surface. When the initial shape deviation data (D) initial When the twisting is spiral, the front and rear clamps of the tensioning machine are controlled to generate a relative rotation angle, and an axial tensile force is applied for correction.

[0054] In this embodiment, the actual stretching rate is controlled within the range of -1.5% to +0.5% of the optimal stretching and straightening parameters.

[0055] In this embodiment, step S3 further includes: for channel-shaped or I-shaped profiles, dynamically adjusting the lateral auxiliary device of the stretching machine or the roller gap of the subsequent roller straightener according to the flaring or closing trend after demolding.

[0056] Example 2 This embodiment is a specific implementation of the method for producing a complex cross-section building profile of 6063 aluminum alloy using the high-precision aluminum profile hot extrusion forming and straightening coordinated control method of the present invention.

[0057] In this embodiment, the method for coordinated control of hot extrusion forming and straightening of a complex cross-section building profile made of 6063 aluminum alloy includes the following steps: Model Construction (S1): First, the profile cross-section was analyzed, revealing a long cantilever structure that could lead to uneven metal flow. Based on this, a flow-dividing combination die was designed, and the working zone at the corresponding cantilever position was pre-extended. Simultaneously, an initial collaborative model was established, setting the initial extrusion temperature to 480℃, the extrusion speed to 3m / min, and the online air-cooling intensity to medium.

[0058] Extrusion Control (S2): After extrusion begins, the system monitors the extrusion pressure in real time. When an upward trend in extrusion pressure is detected, the controller automatically fine-tunes the extrusion speed to 2.8 m / min. Simultaneously, due to the high discharge temperature, the air-cooling fan speed is automatically increased. Through dynamic adjustments, a stable flow of profiles is ensured, and no obvious twisting is observed upon visual inspection after discharge.

[0059] Straightening Control (S3): Before the profile enters the stretching machine, the vision system detects a slight S-shaped lateral bend and a twist of 0.5° / m. After receiving the data, the collaborative model calculates the optimal parameters: a stretching rate of 1.2%, and controls the straightening rollers to apply a specific amount of pressure to the two opposite apex positions of the S-shaped bend.

[0060] Closed-loop feedback (S4): Final inspection showed that the straightness and torsion of the profile were within tolerance range. All parameters and inspection results from this production were recorded for subsequent model optimization.

[0061] In this embodiment, it was found that by using this method, the yield of this batch of profiles was increased from 92% to over 98% using the traditional method, and both dimensional and shape accuracy met high standards.

[0062] Example 3 This embodiment is a specific implementation of the method for producing 6061 aluminum alloy industrial profiles (prone to coarse grain rings) using the high-precision aluminum profile hot extrusion forming and straightening coordinated control method of the present invention.

[0063] In this embodiment, the steps of the hot extrusion forming and straightening coordinated control method for producing 6061 aluminum alloy industrial profiles are the same as in Embodiment 1.

[0064] In this embodiment, given that 6061 alloy is prone to producing coarse grain rings, the S1 model sets the ingot heating temperature to be strictly controlled at 490°C.

[0065] In this embodiment, a higher extrusion speed is used, and deformation heat compensation temperature is utilized to ensure that the outlet temperature reaches the solution temperature.

[0066] In this embodiment, the depth of the coarse grain ring at the tail of the profile was controlled within 3mm, which meets the requirements of military-grade standards.

[0067] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A method for coordinated control of hot extrusion forming and straightening of high-precision aluminum profiles, characterized in that, Includes the following steps: S1 analyzes the cross-sectional characteristics of the target aluminum profile based on a three-dimensional digital model, and constructs an initial digital model of the extrusion die and an extrusion-straightening collaborative process model; the extrusion-straightening collaborative process model defines the extrusion temperature (T). ex ), extrusion speed (V) ex ), online cooling intensity (C) on The tensile ratio (ε) and tensile speed (V) of the tension leveling machine st The initial mapping relationship between the straightening roll reduction (δ) and the straightening roll reduction (δ). During the extrusion process, S2 applies gradient heating to the ingot, ensuring that the temperature at the front end of the ingot is higher than that at the rear end, while controlling the temperature of the extrusion cylinder to be lower than that of the ingot; it also monitors the extrusion pressure (P) and the discharge temperature (T) in real time. out ), and dynamically adjust the extrusion speed (V) based on monitoring data. ex ) and online cooling intensity (C on ); Before the profiles enter the tension straightening machine, S3 uses an online detection system to scan the initial curvature and torsion of the profiles to obtain initial shape deviation data (D). initial The calculated optimal parameters are input into the collaborative process model, and the tension straightening machine straightens the profile according to the calculated optimal parameters. S4 performs final accuracy testing on the straightened profile and stores the initial shape deviation data, final shape deviation data, and corresponding extrusion and straightening process parameters of the entire production process as a set of data in the process database for optimizing the collaborative process model.

2. The method for coordinated control of high-precision aluminum profile hot extrusion forming and straightening according to claim 1, characterized in that, In step S2, the dynamic adjustment of the online cooling intensity (C) on Specifically, it includes: For aluminum alloy profiles that are prone to producing coarse grain rings, the ingot heating temperature should be controlled within the range of 480-500℃, and the corresponding extrusion speed should be matched accordingly. For flat or hollow profiles, non-contact cooling methods such as air cooling or mist cooling are used to prevent black spots from forming on the profile surface.

3. The method for coordinated control of high-precision aluminum profile hot extrusion forming and straightening according to claim 1, characterized in that, Step S2 also includes: The system monitors fluctuations in extrusion pressure (P) in real time and automatically fine-tunes the extrusion speed (V) when it detects sawtooth-like pressure fluctuations that indicate the formation of bite marks or stop marks. ex To restore the smoothness of metal flow; during the extrusion process, nitrogen gas is sprayed into the exit of the die working strip for protection to prevent oxidation of the working strip surface, thereby reducing the generation of pits and burr defects.

4. The method for coordinated control of high-precision aluminum profile hot extrusion forming and straightening according to claim 1, characterized in that, In step S2, the method further includes controlling the dimensional fit gap between the extrusion cylinder and the extrusion pad to be between 0.2 mm and 0.5 mm, so as to prevent air from being drawn into the ingot during the extrusion process and forming bubbles or peeling defects. The length of the extrusion residue should be controlled to be no less than 10% of the ingot diameter to ensure that oxides and impurities on the surface of the ingot are trapped in the residue and prevented from flowing into the product to form oxide streaks or extrusion tails.

5. The method for coordinated control of high-precision aluminum profile hot extrusion forming and straightening according to claim 1, characterized in that, In step S3, the adaptive calculation of the optimal tension straightening parameters specifically includes: Based on the alloy properties and profile condition, a critical elongation threshold is set. Under the premise of ensuring the elimination of unevenness, the actual elongation is controlled to be lower than the threshold to prevent orange peel defects from forming on the profile surface. When the initial shape deviation data (D) initial When the twisting is spiral, the front and rear clamps of the tensioning machine are controlled to generate a relative rotation angle, and an axial tensile force is applied for correction.

6. The high-precision aluminum profile hot extrusion forming and straightening coordinated control method according to claim 5, characterized in that, The actual stretching rate is controlled within the range of -1.5% to +0.5% of the optimal stretching and straightening parameters.

7. The method for coordinated control of high-precision aluminum profile hot extrusion forming and straightening according to claim 1, characterized in that, Step S3 also includes: for channel or I-shaped profiles, dynamically adjusting the lateral auxiliary device of the stretching machine or the roll gap of the subsequent roller straightener according to the flaring or closing trend after demolding.

8. An extrusion die for implementing the high-precision aluminum profile hot extrusion forming and straightening coordinated control method according to any one of claims 1-7, characterized in that, The mold includes a working strip, the length of which is designed differently based on the predicted metal flow rate. The length of the working strip is increased in areas with high metal flow rate, and decreased in areas with low metal flow rate or a flow-promoting angle is set. The cutting edge of the mold working strip is sharp, and the surface of the working strip is uniformly nitrided.

9. The extrusion die according to claim 8, which realizes a method for coordinated control of high-precision aluminum profile hot extrusion forming and straightening, is characterized in that, The extrusion die is a flow-dividing combination die. For hollow profiles, the welding cavity structure of the flow-dividing combination die is optimized, and the flow-dividing ratio and welding chamber depth are adjusted to ensure complete welding of the metal flow. The flow-dividing ratio is in the range of 2.5 to 4.0 to ensure sufficient aluminum supply in the welding cavity and prevent poor welding. The diameter of the circumscribed circle of the shunting die and the extruded profile is smaller than the inner diameter of the extrusion cylinder, with a single-sided allowance of at least 13mm, to prevent the surface metal of the ingot from being rolled into the product and forming defects.