Aluminum profile straightening method using aluminum bar as raw material

Abstract

The application is a kind of aluminum profile straightening processing method taking aluminum bar as raw material, relates to the aluminum profile processing technical field, and comprises: raw material pretreatment, extrusion molding, straightening scheme determination and precision detection.In the application, a whole-process quality control system is constructed from raw material pretreatment to post-treatment storage; the straightening scheme relies on characteristic parameterization, accurate pressure regulation, matching pressure maintenance, targeted stress release and solves the problem of stress concentration of special-shaped cross section; the precision detection covers multi-dimensional shape and position tolerance and defects, and the data is fully traced back to provide support for quality closed-loop control; the post-treatment standardizes surface protection and storage to prevent performance degradation; the whole process is coordinated, and the straightness, stress uniformity and dimensional accuracy of the aluminum profile are greatly improved to meet the demand of high-end fields for high-quality profiles.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aluminum profile processing, in particular to an aluminum profile straightening processing method taking aluminum bars as raw materials. BACKGROUND

[0002] In the modern industrial system, aluminum profiles are widely used in many fields such as building curtain walls, rail transit, electronic equipment frames, etc. due to their light weight, high strength, easy processing and other advantages. With the continuous improvement of product precision and performance requirements in various industries, the control of aluminum profile processing quality is becoming increasingly critical. The straightening process, as the core link of determining the straightness and stress distribution of aluminum profiles, directly affects the assembly accuracy and service life of downstream products. However, the existing aluminum profile straightening processing method taking aluminum bars as raw materials still has many shortcomings in the whole process control, which restricts the further improvement of aluminum profile quality.

[0003] In the core straightening link, the existing technology lacks customized straightening strategies for profiles with different cross-sectional characteristics (such as thin-walled, thick-walled, and irregular cross-sections), and the universal straightening parameters are difficult to adapt to the stress concentration and force transmission dead angle problems of complex cross-sections;

[0004] At the same time, the stress detection means is single, which cannot accurately locate the high stress area and dynamically adjust the straightening parameters, resulting in uneven residual stress distribution of the straightened profile, affecting the long-term stability of the product;

[0005] In addition, the precision detection relies mainly on manual or conventional equipment, with limited detection dimensions and poor data traceability, making it difficult to form a closed loop of whole-process quality control. Unstandardized operation in the post-processing and storage link also causes qualified profiles to lose the precision advantage accumulated in the early processing due to surface corrosion and improper storage deformation. Therefore, there is an urgent need for a whole-process optimization method covering raw material pretreatment, extrusion molding, straightening control, precision detection, and post-processing storage to systematically solve the quality pain points in aluminum profile straightening processing and meet the demand for high-precision and high-performance aluminum profiles in high-end manufacturing fields.

[0006] Therefore, there is a need for an aluminum profile straightening processing method taking aluminum bars as raw materials to address the aforementioned problems. SUMMARY

[0007] The present application relates to the technical field of aluminum profile processing, in particular to an aluminum profile straightening processing method taking aluminum bars as raw materials.

[0008] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0009] An aluminum profile straightening processing method taking aluminum bars as raw materials, comprising:

[0010] Raw material pretreatment: through screening, cleaning the surface of aluminum bar and preheating as needed, eliminate inherent defects of raw materials, provide qualified billet for subsequent processing;

[0011] Extrusion molding: the aluminum bar is extruded into a specific cross-section profile and cooled and shaped, the molding quality is controlled to reduce the difficulty of subsequent straightening;

[0012] Straightening scheme determination: customized straightening scheme, stress detection technology and equipment calibration specification are carried out, the profile adaptation scheme of the straightening machine equipment is refined, three-dimensional stress imaging is introduced for pre-detection and positioning, and the equipment calibration cycle of the straightening process is introduced;

[0013] Precision detection: the dimensional accuracy, geometric tolerance and surface quality of the profile are detected through multiple dimensions to verify the straightening effect and record the data for traceability.

[0014] Preferably, the raw material pretreatment specifically includes the following parts:

[0015] Check whether there are casting defects on the surface of the aluminum bar;

[0016] Use a laser diameter gauge to measure along the length of the aluminum bar at a preset length; when detecting straightness, place the aluminum bar on a precision detection platform and measure the maximum bending amount;

[0017] Detect whether there are defects inside the aluminum bar; perform hardness sampling inspection on key batches of aluminum bars;

[0018] Grind the surface of the aluminum bar with thick oxide skin to expose the metal matrix;

[0019] Soak the aluminum bar in a weak alkaline cleaning solution to remove surface grease;

[0020] Use a box-type resistance furnace or a continuous heating furnace for heating.

[0021] Preferably, the extrusion molding specifically includes the following parts:

[0022] Use an induction heating furnace to heat the aluminum bar to avoid extrusion cracking caused by local overheating; reduce the temperature difference between the aluminum bar and the mold;

[0023] Select a hydraulic extruder;

[0024] Low-speed extrusion, gradually increase the speed after the aluminum bar fills the mold cavity, keep the extrusion speed and pressure stable, and monitor the profile outlet temperature in real time;

[0025] For simple cross-section profiles, use a water cooling tank to cool; for complex profiled profiles, use forced air cooling, and blow evenly to the profile surface through multiple air nozzles;

[0026] After cooling, limit the deformation of the profile through the sizing roller group, and the spacing between the sizing rollers matches the cross-sectional size of the profile.

[0027] Preferably, the straightening scheme is determined, specifically including the following parts:

[0028] Adapting appropriate straightening solutions based on profile characteristics:

[0029] Multi-point stress scanning of the profile is performed to generate a stress cloud map. When the local stress exceeds the preset standard, it is marked as a straightening mark area. Based on the characteristics of the straightening mark area, the corresponding straightening operation is matched.

[0030] The parallelism of the straightening rollers is checked monthly using a laser interferometer, and if the deviation exceeds the limit, it is calibrated by adjusting the fine-tuning bolts; the pressure sensor is calibrated quarterly using a standard force gauge; the straightened profile is placed in a constant temperature aging chamber to release residual stress, and then a second straightness test is performed.

[0031] Preferably, when the local stress exceeds a preset standard, it is marked as a straightening mark area, and a corresponding straightening operation is matched based on the characteristics of the straightening mark area. The process includes:

[0032] Obtain the number of corners in the straightening marking area and the angle of each corner. Sort the angles of each corner in ascending order of size and extract the angle of the smallest corner, which is recorded as the marking angle. Divide 180° by the marking angle, and then divide the result by the total number of corners to obtain the final corner occupancy.

[0033] The corner parameter value is calculated by multiplying the number of corners by 5 and the corner occupancy.

[0034] Obtain the number of cavities in the straightening marking area, as well as the depth and wall thickness of each cavity. Take half the depth of each cavity and divide it by the wall thickness. Sort the resulting values ​​in descending order of magnitude, extract the values ​​greater than 1, count the number of values, and divide by the number of cavities to obtain the cavity degree.

[0035] Obtain the maximum and minimum wall thickness of each cavity in the straightening marking area, and divide the maximum wall thickness by the minimum wall thickness to obtain the wall thickness ratio.

[0036] The corner parameter value, cavity size, and wall thickness ratio are weighted and summed, and the resulting value is summed with the preset basic compensation coefficient to obtain the feature compensation coefficient.

[0037] Preferably, the pressure matching based on the feature compensation coefficient includes:

[0038] ;

[0039] in,

[0040] Basic straightening pressure;

[0041] This represents the maximum initial stress that can be detected within the straightening marking area;

[0042] The characteristic compensation coefficient;

[0043] This is the final straightening pressure.

[0044] Preferably, the preset range of multiple threshold values, and each threshold value range corresponds to a holding time, are used to match the feature compensation coefficient with the range of multiple threshold values ​​to obtain the holding time corresponding to the feature compensation coefficient.

[0045] Preferably, the accuracy detection specifically includes the following parts:

[0046] For long profiles, a laser collimator is used, with the laser beam as the reference line. The deviation between the profile surface and the reference line is measured by a sensor, and the location and value of the maximum bending point are recorded. For short profiles, a precision marble platform is placed, and a dial indicator is used to measure the straightness error at preset intervals along the length of the profile.

[0047] A coordinate measuring machine is used to scan the profile section to obtain key dimensions, which are then compared with the drawings to determine whether they are up to standard.

[0048] The two ends of the profile are fixed on a special fixture, and the torsion angle of the profile in the free state is measured by a torque sensor;

[0049] A flatness tester is used to place the profile on a vacuum adsorption platform. The surface is scanned by a grating sensor to generate a flatness error cloud map and determine whether it is qualified.

[0050] In terms of appearance, the surface of the profile is irradiated with strong light to check for indentations, scratches, and cracks caused during the straightening process; in terms of internal defects, for critical load-bearing profiles, an eddy current flaw detector is used to check for micro-cracks near the surface caused by straightening.

[0051] Preferably, the post-processing and storage involves: surface protection of qualified profiles, cutting and processing as needed, and then storing them according to specifications to ensure performance and avoid deformation.

[0052] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0053] 1. This invention constructs a full-process quality control system from raw material pretreatment to post-processing and storage; the straightening scheme relies on characteristic parameterized precise pressure adjustment and matching pressure holding to release stress in a targeted manner, solving the problem of stress concentration in irregular cross-sections; precision detection covers multi-dimensional geometric tolerances and defects, with full data traceability, providing support for closed-loop quality control; post-processing standardizes surface protection and storage to prevent performance degradation; the entire process is coordinated, significantly improving the straightness, stress uniformity, and dimensional accuracy of aluminum profiles, meeting the demand for high-quality profiles in high-end fields.

[0054] 2. This invention transforms empirical processes into data-driven models through dynamic matching of characteristic compensation coefficients with pressure and holding time. New materials / batch models can quickly calculate adaptation parameters without repeated trial and error. Equipment linkage enables automated diversion and data traceability, reducing human intervention errors and management costs. Standardized and parameterized operations from raw materials to finished products improve production consistency and stability, and reduce defect rates. Overall efficiency is improved, helping enterprises reduce costs and increase efficiency, enhance market competitiveness, and meet the efficient and flexible production needs of modern industry. Attached Figure Description

[0055] Further details, features, and advantages of this application are disclosed in the following description of exemplary embodiments in conjunction with the accompanying drawings, in which:

[0056] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0057] Several embodiments of this application will now be described in more detail with reference to the accompanying drawings to enable those skilled in the art to implement this application. This application may be embodied in many different forms and for various purposes and should not be limited to the embodiments set forth herein. These embodiments are provided to make this application thorough and complete, and to fully convey the scope of this application to those skilled in the art. The embodiments described do not limit this application.

[0058] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It will be further understood that terms such as those defined in commonly used dictionaries shall be interpreted as having a meaning consistent with their meaning in the relevant field and / or the context of this specification, and shall not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0059] Example 1

[0060] Its specific implementation method is combined with the appendix Figure 1 Please provide a detailed explanation.

[0061] Appendix Figure 1The flowchart of an aluminum profile straightening process using aluminum rods as raw materials, provided for an embodiment of the present invention, illustrates the complete steps from raw material pretreatment to post-treatment and storage.

[0062] Please see Figure 1 A method for straightening aluminum profiles using aluminum rods as raw materials, comprising the following parts:

[0063] Raw material pretreatment: By screening, cleaning the surface of aluminum rods and preheating as needed, inherent defects in the raw materials are eliminated, providing qualified billets for subsequent processing;

[0064] Specifically, it includes the following parts:

[0065] Use high-definition visual inspection equipment (resolution ≥ 12 million pixels) or manual visual inspection to check whether there are casting defects such as cracks (deep > 0.5 mm must be removed), shrinkage cavities, bubbles, and inclusions (such as metal oxide particles) on the surface of aluminum bars; when checking the oxide scale thickness, use an eddy current thickness gauge to measure it. If the oxide scale thickness exceeds 50 μm, it must be cleaned, otherwise it will lead to increased wear of the die during extrusion.

[0066] Regarding diameter deviation, a laser diameter gauge (accuracy ±0.01mm) is used to measure along the length of the aluminum rod with a preset length as the reference to ensure that the diameter deviation is within ±0.3mm (adjusted according to the profile specifications); when checking straightness, the aluminum rod is placed on a precision testing platform (flatness ≤0.02mm / m), and the maximum bending amount is measured with a dial indicator. Aluminum rods with bending >1mm / m need to be marked separately, and the correction force should be increased during subsequent straightening.

[0067] Ultrasonic flaw detectors (frequency 2~5MHz) are used to detect whether there are defects such as porosity and segregation (uneven distribution of alloying elements) inside the aluminum bars. The flaw detection results must comply with GB / T6519~2016 "Ultrasonic Testing Method for Wrought Aluminum Alloy Products". Hardness sampling tests (Brinell hardness tester HBW2.5 / 187.5) are conducted on key batches of aluminum bars to ensure that the hardness fluctuation range is ≤±5HBW, so as to avoid rebound after straightening due to uneven material.

[0068] For aluminum rods with thick oxide scale, use a belt polisher (80~120 mesh) to polish the surface at a speed of 10~15m / min to remove the surface layer with a thickness of 30~50μm, exposing the bright metal substrate; after polishing, use compressed air (pressure 0.4~0.6MPa) to blow away the surface dust to prevent residual particles from entering subsequent processes;

[0069] Prepare a weakly alkaline cleaning solution (e.g., 5% sodium carbonate plus 2% sodium phosphate solution, temperature 50~60℃), immerse the aluminum rod for 5~10 minutes to remove surface oil (residual oil content must be ≤5mg / m², verified by fluorescence detection method); after cleaning, rinse 2~3 times with deionized water, and then dry with hot air (temperature 80~100℃, time 3~5 minutes) to ensure surface moisture content ≤0.5%;

[0070] Heating is carried out using a box-type resistance furnace or a continuous heating furnace, with a temperature control accuracy of ±5℃ and a furnace temperature uniformity of ≤±10℃ (to avoid local overheating).

[0071] For high-strength alloys such as 6061 and 7075, the preheating temperature is 120~180℃, and the holding time is 1~2 hours (adjusted according to the diameter of the aluminum rod; for every 50mm increase in diameter, the holding time is extended by 30 minutes). The heating rate is ≤5℃ / min to avoid internal stress caused by thermal shock; the cooling method is to cool down with the furnace to below 50℃ to prevent hardness rebound caused by rapid cooling.

[0072] Extrusion molding: aluminum rods are extruded into profiles with specific cross-sections and cooled to set the shape, controlling the molding quality to reduce the difficulty of subsequent straightening;

[0073] Specifically, it includes the following parts:

[0074] The aluminum rod is heated in an induction heating furnace to 400~500℃ (lower limit for 1 series pure aluminum, upper limit for 7 series alloys), with a temperature uniformity of ±10℃ to avoid extrusion cracking caused by local overheating; for die heating, the die is preheated to 300~400℃ to reduce the temperature difference between the aluminum rod and the die, thereby reducing extrusion resistance and die wear.

[0075] A hydraulic extrusion press is selected (the tonnage is selected according to the size of the profile cross-section, usually 500~3000 tons), the extrusion speed is adjustable (0.5~5m / min), and the pressure control accuracy is ±1MPa; in terms of mold design, the surface roughness of the cavity Ra≤0.8μm is used to ensure the smooth surface of the profile; for irregular cross-sections, a guide mold is required to reduce uneven metal flow.

[0076] During the initial stage, extrusion is carried out at a low speed (0.5~1m / min). After the aluminum rod fills the mold cavity, the speed is gradually increased to avoid cross-sectional deformation in the initial stage. During the stabilization stage, the extrusion speed and pressure are kept stable, and the profile exit temperature is monitored in real time by an infrared thermometer (controlled within 500~550℃) to prevent overheating and resulting grain coarsening.

[0077] For simple cross-section profiles (such as round bars and square tubes), a water cooling tank (water temperature 20~30℃) is used for cooling, with the profile immersed to a depth of 50~100mm and a cooling length of 3~5m, to ensure that the temperature drops rapidly from the extrusion temperature to below 100℃; for complex irregular profiles, forced air cooling (fan speed 15~20m / s) is used, with multiple sets of air nozzles blowing evenly onto the profile surface to avoid warping caused by excessively rapid local cooling;

[0078] After cooling, the profile deformation is restricted by a set of shaping rollers (made of wear-resistant cast iron with chrome plating). The spacing between the shaping rollers matches the profile cross-sectional dimensions (gap ≤ 0.1mm) to ensure the accuracy of the cross-sectional dimensions.

[0079] Straightening scheme determination: Starting from customized straightening schemes for different profiles, stress detection technology and equipment calibration specifications, refine the profile adaptation scheme of the straightening machine equipment, introduce three-dimensional stress imaging for pre-detection and positioning, and adjust the equipment calibration cycle of the straightening process to improve straightening accuracy and stability;

[0080] Specifically, it includes the following parts:

[0081] Adapting appropriate straightening solutions based on profile characteristics:

[0082] For thin-walled pipes (wall thickness 0.5~1mm), the roller straightener adopts a flexible straightening mode, with the upper roller pressure controlled at 5~10kN and the straightening speed at 8~10m / min to avoid crushing. For thick-walled profiles (wall thickness ≥5mm), an enhanced straightening program is activated, adding two sets of auxiliary pressure rollers and gradually increasing the pressure reduction (each increase of 0.05mm) to ensure full release of internal stress. The pressure straightener's pressure head adopts a detachable design, and is equipped with 30+ types of special pressure heads for irregular cross-sections. During replacement, quick calibration is achieved using positioning pins (tolerance H7 / g6), with a positioning error ≤0.02mm.

[0083] X-ray stress analyzer is used to perform multi-point stress scanning on the profile to generate stress cloud map. When the local stress is greater than the preset standard, it is marked as a straightening mark area. Based on the characteristics of the straightening mark area, the corresponding straightening operation is matched.

[0084] The process includes:

[0085] Obtain the number of corners in the straightening marking area and the angle of each corner. Sort the angles of each corner in ascending order of size and extract the angle of the smallest corner, which is recorded as the marking angle. Divide 180° by the marking angle, and then divide the result by the total number of corners to obtain the final corner occupancy.

[0086] The corner parameter value is calculated by multiplying the number of corners by 5 and the corner occupancy.

[0087] The number of corners divided by 5 is a preset standard threshold, which can be modified according to the actual situation;

[0088] In irregular cross-sections, the smallest corner (acute angle) is the area of ​​most significant stress concentration (where metal flow is most severely impeded and residual stress is highest). By sorting the angles in ascending order to extract the smallest angle, the straightening difficulties can be directly identified.

[0089] Avoid vague judgments based on average angles or random angle selection. For example, in a profile with a 90° angle and two 60° corners, the 60° acute angle is the core of stress concentration, and it is more effective to compensate for the pressure by prioritizing it.

[0090] The corner octane is calculated by dividing 180 by the marked angle (reflecting sharpness) and then by the total number of corners (reflecting distribution density). This transforms the empirical rule that the sharper and more numerous the corners, the more difficult it is to release stress into a calculable numerical value.

[0091] The relationship between quantitative geometric features and process difficulty is important. For example, the angular footprint of five 60° corners (180 divided by 60 divided by 5 equals 0.6) is much larger than that of three 120° corners (180 divided by 120 divided by 3 equals 0.5), which requires a higher compensation coefficient to make process adjustments more justifiable.

[0092] Obtain the number of cavities in the straightening marking area, as well as the depth and wall thickness of each cavity. Take half the depth of each cavity and divide it by the wall thickness. Sort the resulting values ​​in descending order of magnitude, extract the values ​​greater than 1, count the number of values, and divide by the number of cavities to obtain the cavity degree.

[0093] The depth-to-width ratio of a single cavity is calculated by dividing half the depth by the wall thickness (the depth of half is an empirical value to balance the stress characteristics at the cavity entrance and in the middle). Then, values ​​>1 are filtered in descending order to accurately identify deep and narrow cavities (these types of cavities have high resistance to force transmission and are prone to stress dead zones).

[0094] It can distinguish between shallow cavities (easy to straighten) and deep, narrow cavities (difficult to straighten). For example, a shallow cavity (1 / 2 depth divided by wall thickness equals 0.8) and a deep, narrow cavity (1 / 2 depth divided by wall thickness equals 1.5) will not affect compensation, while the latter needs to be weighted more heavily to avoid over-straightening / under-straightening caused by cutting all cavities in the same way.

[0095] The cavity degree is obtained by dividing the number of values ​​greater than 1 by the total number of cavities. The proportion of deep and narrow cavities is converted into a quantitative parameter. For example, if there are 2 deep and narrow cavities out of 3 cavities, the cavity degree is 2 / 3≈0.67, which intuitively reflects the proportion of areas where force transmission is obstructed.

[0096] It can quantify the impact of cavity structure complexity on straightening. For example, multi-cavity thin-walled profiles (such as automotive heat pipes) have high cavity complexity and require higher compensation pressure to penetrate the cavity, making process adjustments more in line with actual needs.

[0097] Obtain the maximum and minimum wall thickness of each cavity in the straightening marking area, and divide the maximum wall thickness by the minimum wall thickness to obtain the wall thickness ratio.

[0098] The ratio of maximum wall thickness to minimum wall thickness directly reflects the difference in wall thickness. The larger the ratio (e.g., 3:1), the more likely there are areas of large local rigidity differences in the profile (thick-walled areas are difficult to deform, while thin-walled areas are prone to over-straightening).

[0099] Early identification of deformation risks, such as profiles with a wall thickness ratio of 2.5, requires higher pressure in thick-walled areas to straighten them, while pressure needs to be controlled in thin-walled areas to avoid cracking. Differential compensation can be achieved through parameter weighting.

[0100] The corner parameter value, cavity size, and wall thickness ratio are weighted and summed, and the resulting value is summed with the preset basic compensation coefficient to obtain the feature compensation coefficient.

[0101] This includes: pre-setting weighting factors for corner parameters, cavity size, and wall thickness ratio; multiplying the corner parameters, cavity size, and wall thickness ratio with their corresponding weighting factors and summing the results; and summing the resulting values ​​with the basic compensation coefficient to obtain the feature compensation coefficient.

[0102] The basic compensation coefficient is set according to the material of the profile. For example, it is 1.0 for 6-series alloys and 1.2 for 7-series alloys, because high-strength alloys require higher pressure.

[0103] Corner parameters (corner stress), cavity size (force transmission resistance), and wall thickness ratio (risk of uneven deformation) are linked by weights to transform the multi-dimensional defects of complex cross sections into a single compensation coefficient, which is directly related to the straightening pressure.

[0104] For example, the basic compensation coefficient of 7-series alloys (high strength) is 1.2. If there are sharp corners (high corner parameter value), deep and narrow cavities (high cavity degree), and uneven wall thickness (large ratio), the weighted compensation coefficient is further improved, which can accurately adapt to extreme scenarios with hard materials and many structural defects.

[0105] The pressure corresponding to the feature compensation coefficient matching includes:

[0106] ;

[0107] in,

[0108] The basic straightening pressure (set according to the cross-sectional area of ​​the profile, such as 50kN for a 50×50mm cross-section);

[0109] This represents the maximum initial stress that can be detected within the straightening marking area; the higher the stress, the greater the pressure increase.

[0110] K is the characteristic compensation coefficient; to avoid overcorrection, the maximum value of K is set to 2.5 (corresponding to a pressure increase of ≤150%).

[0111] Limit K to ≤ 2.5 (corresponding to a pressure increase of ≤ 150%) to prevent excessive pressure caused by abnormal characteristic parameters (such as too many sharp corners), which could crush the profile or generate new residual stress.

[0112] For example, for extreme irregular cross-sections (eight acute-angled deep cavities), even if the calculated K value reaches 3.0, it is forced to be executed as 2.5 to ensure that the profile is under-crimped rather than over-crimped, reducing the risk of scrapping;

[0113] For the final straightening pressure;

[0114] If residual stress > 50 MPa is detected in the target area after straightening, according to Corrections are made to ensure that stress release meets the standards; even if there are deviations in the initial pressure calculation, a closed-loop detection and correction system can be used to ensure that the final residual stress is ≤50MPa, thus protecting the mechanical properties of the profile.

[0115] Basic straightening pressure The base pressure is set according to the cross-sectional area (e.g., 50kN for 50×50mm), standardizing the rule that the larger the cross-section, the greater the straightening force required, and avoiding excessive pressure for small cross-sections or insufficient pressure for large cross-sections.

[0116] For example, a 30kN base pressure is used for small cross-section thin-walled profiles (such as 30×30mm) to ensure straightening effect while avoiding crushing the profile; a 100kN base pressure is used for large cross-section thick-walled profiles (such as 100×100mm) to ensure that the force can penetrate the interior.

[0117] Increased pressure By calculating the increase using a characteristic compensation coefficient and the maximum initial stress, a precise linkage between higher stress and greater pressure can be achieved; for example... =150MPa (high stress) and K=2.0, increase = (2-1)×150 / 100=1.5, total pressure = ×2.5, powerfully releases high stress;

[0118] It addresses stress concentration areas in a targeted manner, avoiding the problem of unstraightened high-stress areas and over-straightened low-stress areas caused by uniform pressure. It is especially suitable for irregular cross-sections (where there are large stress differences at corners and cavities).

[0119] Pressure calculation modeling (input section, stress, K value to output pressure) eliminates the need for repeated trial straightening when producing new materials / new batches. Directly substitute into the formula for calculation, reducing production line downtime for debugging.

[0120] Especially for multi-variety, small-batch irregular profiles (such as customized door and window profiles), the process parameters can be quickly switched to improve the flexibility of the production line;

[0121] Multiple threshold ranges are preset, and each threshold range corresponds to a holding time. The feature compensation coefficient is matched with the ranges of the multiple thresholds to obtain the holding time corresponding to the feature compensation coefficient.

[0122] Different characteristic compensation coefficients correspond to different degrees of stress concentration and force transmission difficulty in the profiles:

[0123] Low K value (e.g., K=1.0~1.5): The stress distribution of the profile is relatively uniform, the resistance to force transmission is small, and the holding time can be short (e.g., 5~8s), avoiding excessive holding time and energy waste.

[0124] High K value (e.g., K=2.0~2.5): The profile has complex features such as sharp corners and deep and narrow cavities, and the stress release is slow. It is necessary to extend the pressure holding time (e.g., 12~18s) to ensure that the force penetrates into the deep area;

[0125] By covering the continuous change of K value with a threshold range, the pressure holding time is upgraded from a one-size-fits-all approach to a gradient adaptation, so that the pressure holding action fits the actual stress release requirements of the profile.

[0126] When straightening aluminum profiles, there is a time lag in the transmission of force from the surface to the interior (especially in complex cross-sections, where force is easily blocked by cavities and corners); a high K value corresponds to a longer holding time, which essentially allows sufficient time for stress release.

[0127] For example, for deep cavity profiles (K=2.2), holding the pressure for 15 seconds allows the force to gradually penetrate the cavity, avoiding the situation where the pressure is sufficient but the time is too short to straighten the surface and leave residual internal stress.

[0128] By compensating for time delays, the spatial lag in force transmission is made up to ensure that stress is released evenly from the surface to the core of the profile.

[0129] Once the relationship between the preset threshold and the holding time is established, operators no longer need to adjust the holding time based on experience.

[0130] Simply calculate the characteristic compensation coefficient K to automatically match the holding time (e.g., if K=1.8 falls within the range of [1.7~2.0], directly call 12s holding time).

[0131] Especially for new employees or scenarios involving switching between multiple product types, this reduces the cycle from trial pressure testing to rework and shortens the production line debugging cycle;

[0132] The laser bending tester is linked with the robot loading and unloading system. When the robot detects out-of-tolerance profiles, it automatically moves them to the rework area. Qualified products go directly into the straightening machine, realizing fully automated diversion of the entire process.

[0133] The parallelism of the straightening rollers is checked monthly using a laser interferometer. If the deviation exceeds the limit, it is calibrated using fine-tuning bolts (adjustment accuracy 0.005mm / division). The pressure sensor is calibrated quarterly using a standard force gauge (accuracy ±0.1%FS) to ensure that the pressure display error is ≤1%. After straightening, the profile is placed in a constant temperature aging chamber (temperature 25±2℃, humidity 50±5%) for 24 hours to release residual stress. Then, a second straightness test is performed to ensure stability (deformation ≤0.1mm / m within 24 hours).

[0134] Precision inspection: The dimensional accuracy, geometric tolerances and surface quality of the profiles are inspected from multiple dimensions to verify the straightening effect and record the data for traceability;

[0135] Specifically, it includes the following parts:

[0136] For long profiles (length > 3m), a laser collimator (measurement range 0~10m, accuracy ±0.01mm / m) is used. The laser beam is used as a reference line, and the deviation between the profile surface and the reference line is measured by a sensor. The location and value of the maximum bending point are recorded. For short profiles (length < 3m), they are placed on a precision marble platform (flatness 0.01mm / m), and a dial indicator (accuracy 0.01mm) is used to measure the straightness at preset intervals along the length of the profile. The straightness error is calculated (≤0.5mm / m is acceptable).

[0137] A coordinate measuring machine (CMM) with a measuring range of 500×500×500mm and an accuracy of ±0.005mm is used to scan the profile cross-section to obtain key dimensions (such as diameter, wall thickness, and outline dimensions of irregular cross-sections). These dimensions are then compared with the drawings, and the tolerances must be controlled within ±0.1mm (±0.05mm for precision parts). For pipes, the uniformity of the inner diameter, outer diameter, and wall thickness must be checked. A wall thickness micrometer (accuracy 0.01mm) is used to measure at four quadrant points on the same cross-section, and a wall thickness difference ≤0.1mm is considered acceptable.

[0138] The two ends of the profile are fixed to a special fixture, and the torsion angle of the profile in free state is measured by a torque sensor (twist degree ≤ 0.5° per meter length is qualified); for irregular profiles, the images of the cross sections at both ends can be taken by an image measuring instrument (magnification 50~200 times), and the offset angle of the cross section center line can be compared to calculate the amount of torsion.

[0139] A flatness tester is used to place the profile on a vacuum adsorption platform. The surface is scanned by a grating sensor to generate a flatness error cloud map. A flatness of ≤0.2mm / m is considered acceptable.

[0140] In terms of appearance, the profile surface is irradiated with strong light (illuminance ≥ 5000 lux) to check for indentations (depth > 0.05 mm, requiring rework), scratches (length > 5 mm, requiring treatment), and cracks (any visible crack is considered unqualified) caused during the straightening process. In terms of internal defects, for critical load-bearing profiles, an eddy current flaw detector (frequency 1~10MHz) is used to detect whether there are micro-cracks caused by straightening near the surface (depth 0~5 mm).

[0141] All test data (straightness, dimensional tolerances, surface defects, etc.) are automatically stored in the database, linked to the profile batch number, straightening equipment number, and operator information, and can be traced by scanning a code (retention period ≥ 3 years).

[0142] Post-processing and storage: Qualified profiles are surface protected, cut and processed as needed, and then stored according to specifications to ensure performance and avoid deformation.

[0143] include:

[0144] Surface protection treatments include anodizing, spraying, and passivation.

[0145] Anodizing: Suitable for profiles requiring corrosion resistance. The process involves degreasing, pickling, anodizing, and sealing.

[0146] Spray coating treatment: During powder coating, the profile surface is phosphated (to form a phosphate film and enhance the adhesion of the coating), and then the powder coating is electrostatically sprayed. The curing temperature is 180~200℃ and the time is 15~20 minutes. The coating adhesion must reach level 1 in GB / T9286 (no peeling in the cross-cut test).

[0147] Passivation treatment: For profiles stored for a short period of time, chromate passivation (concentration 5~10%, temperature 20~30℃, time 1~2 minutes) or chromium-free passivation (environmentally friendly, such as zirconium salt passivation) is used to form a protective film to prevent surface oxidation and discoloration (no rust after salt spray test ≥48 hours).

[0148] Cutting and deep processing include: high-precision sawing machines (such as metal circular saws, saw blade speed 3000~5000rpm), cutting accuracy ±0.1mm (length tolerance), cut perpendicularity ≤0.05mm / 100mm, avoiding profile bending caused by cutting vibration. Laser cutting machines (suitable for irregular cross-sections) with cutting speed 1~5m / min, heat-affected zone ≤0.1mm, preventing thermal deformation from affecting straightening accuracy;

[0149] Chamfer (0.5×45°) or flatten the ends of the cut profiles to remove burrs (burr height ≤0.05mm) and avoid scratching the surface during handling;

[0150] The storage warehouse temperature should be controlled between 15~30℃, and the relative humidity ≤60%. Direct sunlight and ground dampness should be avoided (a moisture-proof mat should be laid on the ground, with a height ≥100mm). Long profiles (>6m) should be stored on horizontal racks (rack flatness ≤0.5mm / m), with 3~5 support blocks (spacing ≤1.5m) under each profile to prevent sagging and bending. Short profiles (<6m) should be stored on vertical racks, fixed at the bottom and limited by elastic clamps at the top to prevent tipping and collision.

[0151] Each batch of profiles is labeled with its specifications, batch number, straightening date, test results, and storage period (usually ≤6 months; if it exceeds this period, the straightness must be retested).

[0152] The above formulas are all dimensionless calculations. The formulas are derived from software simulations based on a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation.

[0153] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

[0154] It should be noted that, in this document, the use of relational terms such as "first" and "second" is merely for distinguishing one entity or operation from another, and does not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0155] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0156] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0157] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0158] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0159] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0160] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0161] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A method for straightening aluminum profiles using aluminum rods as raw materials, characterized in that, Comprise: Raw material pretreatment: through screening, cleaning the surface of aluminum bar and preheating as needed, eliminate inherent defects of raw materials, provide qualified billet for subsequent processing; Extrusion molding: the aluminum bar is extruded into a specific cross-sectional profile and cooled and shaped, the molding quality is controlled to reduce the difficulty of subsequent straightening; Straightening scheme determination: from different profile customized straightening scheme, stress detection technology and equipment calibration specification, refine the profile adaptation scheme of straightening machine equipment, introduce three-dimensional stress imaging for pre-detection and positioning, equipment calibration cycle in the straightening process, improve the straightening precision and stability; Adapt the corresponding straightening scheme based on the characteristics of the profile: Multi-point stress scanning is performed on the profile to generate a stress cloud map. When the local stress is greater than the preset standard, mark it as a straightening marked area. Match the corresponding straightening operation based on the characteristics of the straightening marked area; When the local stress is greater than the preset standard, mark it as a straightening marked area. Match the corresponding straightening operation based on the characteristics of the straightening marked area. The process includes: Obtain the number of corners of the straightening marked area and the angle of each corner. Arrange the angles of each corner in ascending order according to size, and extract the smallest corner angle, denoted as the marker angle. Divide 180° by the marker angle, and divide the resulting value by the total number of corners to obtain the angle fraction. Multiply the value obtained by dividing the number of corners by 5 by the angle fraction to obtain the angle parameter value. The number of corners divided by 5, where 5 is a preset standard threshold, which can be modified according to actual conditions. Obtain the number of cavities of the straightening marked area, as well as the depth and wall thickness of each cavity. Divide the depth of each cavity by the wall thickness to obtain the value, and arrange the values in descending order according to the numerical value. Extract the values greater than 1, and divide the number by the number of cavities to obtain the cavity fraction. Obtain the maximum wall thickness and minimum wall thickness of each cavity of the straightening marked area, and divide the maximum wall thickness by the minimum wall thickness to obtain the wall thickness ratio. Weighted sum of the angle parameter value, cavity fraction and wall thickness ratio, and sum of the resulting value and the preset basic compensation coefficient to obtain the feature compensation coefficient. Match the corresponding pressure based on the feature compensation coefficient, including: ； Wherein, to the base straightening pressure; to straighten the maximum initial stress detectable within the marked area; characteristic compensation coefficient; final straightening pressure; Accuracy detection: detect the dimensional accuracy, geometric tolerance and surface quality of the profile through multi-dimensional detection to verify the straightening effect and record the data for traceability.

2. The method of claim 1, wherein the aluminum bar is a 6N (99.9999%) aluminum bar. Raw material pretreatment, specifically including the following parts: Check if there are casting defects on the surface of the aluminum bar; Use a laser diameter gauge to measure the length of the aluminum bar along the length direction with a preset length as the reference. When detecting straightness, place the aluminum bar on a precision detection platform and measure the maximum bending amount; Detect if there are defects inside the aluminum bar; perform hardness sampling inspection on key batches of aluminum bars; Grind the surface of the aluminum bar with thick oxide skin to expose the metal matrix; Prepare a weak alkaline cleaning solution to soak the aluminum bar and remove surface oil; Use a box-type resistance furnace or a continuous heating furnace for heating.

3. The method of claim 1, wherein the aluminum bar is a 6N (99.9999%) aluminum bar. Extrusion molding, specifically including the following parts: Use an induction heating furnace to heat the aluminum bar to avoid local overheating and cracking during extrusion; reduce the temperature difference between the aluminum bar and the mold; Select a hydraulic extruder; Low-speed extrusion, after the aluminum rod fills the mold cavity, gradually increase the speed, keep the extrusion speed and pressure stable, real-time monitoring of the profile outlet temperature; For simple cross-section profiles, water cooling tank cooling is adopted, for complex profile, forced air cooling is adopted, through multiple groups of air nozzles uniformly blowing to the profile surface; After cooling, the profile deformation is limited by the sizing roller group, and the spacing between the sizing rollers is matched with the profile cross-sectional size.

4. The method of claim 1, wherein the aluminum bar is a 6N (99.9999%) aluminum bar. Based on the profile characteristics, the corresponding straightening scheme is adapted, which also includes: The parallelism of the straightening roller is detected by laser interferometer every month, and the deviation is adjusted by fine tuning screw when the deviation exceeds the limit; the pressure sensor is calibrated by standard dynamometer every quarter; the straightened profile is placed in a constant temperature aging room for standing, and after releasing the residual stress, the straightness is detected again.

5. The method of claim 1, wherein the aluminum bar is a 6N (99.9999%) aluminum bar. The value range of multiple threshold values is preset, and the value range of each threshold value corresponds to a holding time, and the feature compensation coefficient is matched with the value range of the multiple threshold values to obtain the holding time corresponding to the feature compensation coefficient.

6. The method of claim 1, wherein the aluminum bar is a 6N00 aluminum bar. Precision detection, specifically including the following parts: Long profiles, i.e. profiles with a length greater than 3m, use a laser collimator, with a laser beam as a reference line, and measure the deviation of the profile surface from the reference line through a sensor, record the maximum bending point position and value; short profiles, i.e. profiles with a length less than 3m, are placed on a precision marble platform, and a dial gauge is used to measure once every preset distance along the length of the profile, and the straightness error is calculated; Use a three-coordinate measuring machine to scan the profile cross-section, obtain the key dimensions, and compare with the drawing to determine whether it is qualified; Fix the profile at both ends on a special fixture, and measure the torsion angle of the profile in a free state through a torque sensor; Use a flatness detector, place the profile on a vacuum suction platform, scan the surface through a grating sensor, generate a flatness error cloud map, and determine whether it is qualified; In terms of appearance, shine a strong light on the profile surface to check for indentation, scratches, and cracks caused during straightening; In terms of internal defects, for key load-bearing profiles, use an eddy current flaw detector to detect whether there are micro-cracks caused by straightening near the surface.

7. The method of claim 1, wherein the aluminum bar is a 6N (99.9999%) aluminum bar. Post-processing and storage: surface protection, on-demand cutting processing, and storage according to specifications to ensure performance and prevent deformation.

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