Automobile swing arm production method

Abstract

The invention relates to the technical field of automobile part manufacturing, and discloses an automobile swing arm production method which comprises the three steps of machining semi-finished product preparation, sizing material forming semi-finished product preparation and finished product assembling and warehousing. The machined semi-finished product is obtained through blank preparation, rough and finish machining, drilling and inspection; a sizing material forming semi-finished product is obtained through raw material screening, banburying, pre-forming, vulcanization forming, automatic trimming, AI automatic assembling, AI visual inspection and performance testing, AI assembling and visual inspection are in cooperative linkage, and assembling parameters are adjusted in real time according to the detection result; and finished product assembly and inspection are completed after the two semi-finished products are prepared in parallel. According to the invention, the problems of low positioning precision, poor detection efficiency and lack of cooperation in existing production are solved, the product qualification rate and the production efficiency are greatly improved, and the large-scale high-precision production requirement is met.

Description

Technical Field

[0001] This invention relates to the field of automotive parts manufacturing technology, and in particular to an integrated production method for automotive control arms. Background Technology

[0002] As a core load-bearing component of the chassis suspension system, the manufacturing precision and assembly quality of the automotive control arm directly affect the vehicle's driving stability and safety.

[0003] The current production of automotive control arms mostly adopts a hybrid model of machining, manual assembly, and traditional testing, with significant deficiencies in the assembly and testing stages after the rubber molding process.

[0004] In terms of assembly, traditional processes rely on manual labor or a single robotic arm to assemble rubber-molded components and metal connectors. This results in problems such as low positioning accuracy, high randomness in assembly sequence, and insufficient component fit, which can easily lead to uneven stress on the swing arm and shorten its service life. In the inspection stage, manual visual inspection or single-dimensional optical inspection is often used, which is inefficient, has a high error rate, and cannot provide real-time feedback of inspection results to the assembly stage for parameter correction. At the same time, the assembly and inspection stages in the existing process are independent of each other and lack a collaborative mechanism, causing defective products to flow to subsequent processes, increasing production costs, and making it difficult to meet the needs of large-scale, high-precision production. Summary of the Invention

[0005] This invention aims to solve at least one of the following technical problems existing in the current production process of automotive swing arms: low positioning accuracy of assembly after rubber molding, lack of unified standard for assembly sequence, and insufficient fit of parts; low detection efficiency, single detection dimension, and high misjudgment rate; lack of coordination between assembly and detection links, and the inability of detection results to guide the adjustment of assembly parameters in real time; serial production processes lead to long cycle time, making it difficult to meet the needs of large-scale high-precision production.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A method for producing automotive control arms, characterized by comprising the following steps: Step 1: Preparation of semi-finished products by machining. The process involves blank preparation, rough machining, fine machining, drilling, and semi-finished product inspection to obtain semi-finished products by machining. Step 2: Preparation of semi-finished rubber molding products. The process involves raw material screening, rubber mixing, pre-forming, vulcanization molding, automated trimming, AI automated assembly, AI visual inspection and performance testing to obtain semi-finished rubber molding products. Step 3: Finished product assembly and warehousing, which involves semi-finished product assembly, post-assembly inspection, and warehousing of the finished swing arm. Step one and step two are carried out in parallel. The results of the AI ​​visual inspection in step two are fed back to the AI ​​automated assembly process in real time to adjust the assembly parameters.

[0007] In a preferred embodiment of the present invention, step one includes the following steps: Step 1-1: Blank preparation: Select raw materials and form them using a die forging process. After cooling, the blank is obtained. Steps 1-2: Rough machining, rough machining of the blank's outer diameter, end face and steps, leaving machining allowance; Steps 1-3: Machining and finishing, performing finishing on key mating surfaces and mounting hole positioning surfaces of the workpiece after rough machining; Steps 1-4: Drilling, drilling holes in the finished workpiece and then reaming and deburring. Steps 1-5: Semi-finished product inspection. A comprehensive inspection is carried out on the workpiece after drilling. If it passes the inspection, a semi-finished machined product is obtained.

[0008] In a preferred embodiment of the present invention, step two includes the following steps: Step 2-1: Raw material screening, the raw materials for rubber compound are tested and screened according to their indicators; Step 2-2: Rubber compound internal mixing. The rubber raw materials and compounding agents are put into the internal mixer in proportion and mixed in stages with controlled temperature. After passing through the open mill, the mixture is cooled and stored. Steps 2-3: Pre-forming, the thinned rubber material is placed into the pre-forming mold for cold pressing and then visual inspection is performed; Steps 2-4: Vulcanization molding. Place the pre-formed rubber compound into the vulcanization mold and vulcanize it using a flat vulcanizing machine. After cooling, remove the rubber compound parts. Steps 2-5: Automated trimming, using a robotic trimming system to remove burrs and flash from the rubber parts; Steps 2-6: AI-automated assembly, which achieves the assembly of adhesive components and metal connectors through multi-station collaboration; Steps 2-7: AI visual inspection, which involves acquiring multi-angle images and comparing features of the assembled workpiece, and providing feedback on the inspection results; Steps 2-8: Performance testing. Mechanical properties and assembly reliability tests are conducted on the workpieces that pass the AI ​​vision inspection. After passing the tests, the semi-finished product with rubber molding is obtained.

[0009] In a preferred embodiment of the present invention, the raw material of the rubber compound in step 2-1 is nitrile rubber or a blend of natural rubber and nitrile rubber.

[0010] In a preferred embodiment of the present invention, the compounding agents in step 2-2 include vulcanizing agents, accelerators, reinforcing agents, softeners, antioxidants, and activators. The temperature of the first stage of internal mixing is controlled at 80 to 90 degrees Celsius, and the mixing time is 3 to 4 minutes. The temperature of the second stage is controlled at 110 to 120 degrees Celsius, and the mixing time is 2 to 3 minutes. The rotor speed of the internal mixer is 40 to 60 revolutions per minute, the mixing pressure is 0.6 to 0.8 MPa, the thin pass thickness of the open mill is 2 to 3 mm, and the number of thin passes is 3 to 4.

[0011] In a preferred embodiment of the present invention, the vulcanizing agent is sulfur, and its addition amount is 1.5% to 2.5% of the mass of the rubber raw materials; the accelerator is a compound of thiazole accelerator and sulfenamide accelerator, the mass ratio of thiazole accelerator to sulfenamide accelerator is 1:1.5, and the total addition amount is 0.8% to 1.2% of the mass of the rubber raw materials; the reinforcing agent is N330 type high abrasion-resistant carbon black, and its addition amount is 30% to 40% of the mass of the rubber raw materials; The softener is dioctyl phthalate, and the addition amount is 5% to 8% of the mass of the rubber raw materials; the activator is a compound of zinc oxide and stearic acid, wherein the addition amount of zinc oxide is 3% to 5% of the mass of the rubber raw materials, and the addition amount of stearic acid is 1% to 2% of the mass of the rubber raw materials; the antioxidant is a compound of amine antioxidant and phenolic antioxidant, the mass ratio of amine antioxidant to phenolic antioxidant is 1:1, and the total addition amount is 1.0% to 1.5% of the mass of the rubber raw materials.

[0012] In a preferred embodiment of the present invention, the addition process of the compounding agent in step 2-2 is as follows: First, the rubber raw material is put into a mixer for preheating and plasticizing; then, zinc oxide is added from the reinforcing agent, antioxidant, and activator, and the mixture is mixed for 3 minutes at 80 to 90 degrees Celsius and a rotor speed of 40 revolutions per minute; next, a softener is added, and the mixture is mixed for 2 minutes at 85 to 95 degrees Celsius; finally, stearic acid is added from the vulcanizing agent, accelerator, and activator, and the mixture is mixed for 2 to 3 minutes at 90 to 100 degrees Celsius and a rotor speed of 50 to 60 revolutions per minute.

[0013] In a preferred embodiment of the present invention, in step 2-2, the viscosity change of the compound is monitored in real time by the torque sensor of the internal mixer. When the torque value stabilizes at 30 to 40 N·m, the internal mixing process is ended. The roller temperature is controlled at 60 to 70 degrees Celsius during the thin pass of the open mill. After the thin pass, the rubber compound is cooled to room temperature and stored for no more than 24 hours.

[0014] In a preferred embodiment of the present invention, the molding pressure in steps 2-3 is 10 to 15 MPa, and the molding time is 2 to 3 minutes.

[0015] In a preferred embodiment of the present invention, the vulcanization temperature in steps 2-4 is 150 to 160 degrees Celsius, the vulcanization pressure is 20 to 25 MPa, and the vulcanization time is 15 to 20 minutes. The vulcanization time is adjusted according to the thickness of the rubber component. For every 1 mm increase in thickness, the vulcanization time is extended by 1 to 2 minutes. The rubber component is removed after the mold is cooled to below 80 degrees Celsius.

[0016] Compared with the prior art, the present invention has the following significant advantages: By pre-setting assembly logic, multi-station orderly operation, and parameter database support, the assembly actions of rubber components and metal connectors follow a unified standard, avoiding the randomness brought about by manual operation or single robotic arm operation, improving the consistency of component positioning and bonding, and reducing the problem of uneven force distribution caused by improper assembly.

[0017] Employing multi-angle image acquisition and feature comparison technology, it covers multiple dimensions of inspection items such as positioning status, fit, and fastening appearance. Compared with traditional manual visual inspection or single-dimensional inspection, it can more comprehensively identify potential defects and reduce misjudgments caused by inspection limitations.

[0018] Establish a linkage mechanism between assembly and testing. Testing results can be fed back to the assembly stage in a timely manner. Adjust the corresponding process parameters for different types of assembly problems to reduce the flow of defective products to subsequent processes and reduce rework and material waste.

[0019] By adopting a parallel operation mode of machining and rubber molding, combined with a flexibly accessible parameter database, it can adapt to the production needs of different models of automotive swing arms without major equipment adjustments, thus improving the ease of production line switching.

[0020] By controlling the process parameters at each stage of rubber compound preparation, standardizing the assembly process, and conducting multiple inspections and tests, the mechanical properties of the rubber compound components and the overall connection reliability of the swing arm are kept stable, reducing product performance differences caused by production fluctuations. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall steps of the automobile swing arm production method of the present invention; Figure 2 This is a schematic diagram showing the breakdown of the sub-steps in the process of preparing semi-finished products by machining according to the present invention; Figure 3 This is a schematic diagram showing the breakdown of the sub-steps in the preparation of the semi-finished rubber compound of the present invention. Figure 4 This is a breakdown diagram of the sub-steps of the finished product assembly and warehousing process of the present invention; Figure 5 A schematic diagram of the automotive lower suspension arm structure produced for the application of this invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0024] As attached Figure 1 As shown, the present invention provides a method for producing automotive swing arms, which includes the following steps: Step 1: preparation of semi-finished products by machining, i.e., the preparation process from blank to semi-finished product; Step 2: preparation of semi-finished products by molding rubber, i.e., the preparation process from raw materials to semi-finished products; Step 3: assembly and warehousing of finished products, i.e., the assembly, inspection and warehousing process of the two semi-finished products.

[0025] like Figure 2 As shown, step one further includes the following steps: Step 1-1: Blank Preparation. Select materials such as high-quality carbon structural steel (e.g., No. 45) as the raw material for the blank. Based on the dimensions and mechanical performance requirements of the automotive swing arm, use a die forging process to form the blank. Schematic, during die forging, control the forging temperature at 1100 to 1150 degrees Celsius, the forging pressure at 800 to 1000 MPa, and the holding time at that temperature for 30 to 40 minutes to ensure a uniform internal structure and the absence of cracks and porosity defects in the blank. After forging, use natural cooling to cool the blank to room temperature to avoid rapid cooling that could generate internal stress.

[0026] Steps 1-2: Rough Machining. Fix the cooled blank onto the fixture of the CNC lathe. Following the rough machining process, sequentially rough machine the outer diameter, end face, and steps of the swing arm body. In a non-restrictive rough machining process, use carbide cutting tools, controlling the cutting speed to 80-100 m / min, the feed rate to 0.2-0.3 mm / rpm, and the depth of cut to 3-5 mm. The purpose of rough machining is to remove oxide scale and excess material from the blank surface, making the workpiece shape and dimensions close to the design requirements, while reserving a 2-3 mm machining allowance for subsequent finishing.

[0027] Steps 1-3: Machining and Finishing. After rough machining, the workpiece is finished to ensure the dimensional accuracy and surface quality of the swing arm. The rough-machined workpiece is transferred to a machining center, where key mating surfaces and mounting hole positioning surfaces of the swing arm are machined sequentially using processes such as finish milling and finish grinding. In a schematic finishing process, the cutting parameters are adjusted, controlling the cutting speed to 120 to 150 meters per minute, the feed rate to 0.1 to 0.15 millimeters per revolution, and the depth of cut to 0.5 to 1 millimeter.

[0028] Steps 1-4: Drilling. Drilling is performed on the finished workpiece according to the assembly requirements of the automotive control arm. A CNC drilling machine is used, equipped with positioning fixtures to ensure drilling position accuracy. Before drilling, the drilling position is pre-marked. During a schematic drilling process, the drill bit speed is controlled at 1500 to 2000 rpm, and the feed rate is 0.1 to 0.12 mm per rpm. After drilling, a reamer is used to ream the hole, ensuring the hole diameter tolerance is within ±0.01 mm and the hole wall surface roughness Ra ≤ 1.6 micrometers. Simultaneously, the workpiece is deburred after drilling to remove burrs from the hole opening and edges to prevent scratching other components during assembly.

[0029] Steps 1-5: Semi-finished Product Inspection. A combination of general-purpose measuring tools and specialized inspection tools is used to conduct a comprehensive inspection of the drilled workpiece. Inspection items include the workpiece's external dimensions, the flatness and parallelism of key mating surfaces, and the position and diameter of mounting holes. If the inspection is satisfactory, the workpiece is considered a semi-finished product and transferred to the semi-finished product storage area for later use. If the inspection fails, the non-conforming items are marked, and the workpiece is returned to the corresponding machining process for rework. After rework, the workpiece is inspected again until it passes. If rework is not possible, the workpiece is scrapped.

[0030] Step two is the preparation process from raw materials to semi-finished products, such as... Figure 3 As shown, step two includes the following steps: Step 2-1: Raw Material Screening. Nitrile rubber is selected as the raw material for the rubber compound. Based on the oil resistance, wear resistance, and mechanical performance requirements of the automotive swing arm components, the raw materials are screened. Indicatively, the screening indicators include Mooney viscosity, tensile strength, and elongation at break, with Mooney viscosity controlled between 40 and 60, tensile strength ≥ 18 MPa, and elongation at break ≥ 500%. Simultaneously, impurities in the raw materials are tested to ensure that the impurity content is ≤ 0.5%, avoiding any impact on the molding quality of the rubber compound.

[0031] Step 2-2: Rubber Compound Internal Mixing. The selected qualified rubber raw materials and compounding agents are fed into an internal mixer according to a preset ratio for internal mixing. Preferably, the internal mixing process employs a segmented temperature control method. The first segment is controlled at 80 to 90 degrees Celsius for 3 to 4 minutes to ensure the compounding agents are evenly dispersed in the rubber compound. The second segment is controlled at 110 to 120 degrees Celsius for 2 to 3 minutes to promote the chemical reaction between the rubber compound and the compounding agents. More preferably, during the internal mixing process, the rotor speed of the internal mixer is controlled at 40 to 60 revolutions per minute, and the mixing pressure is 0.6 to 0.8 MPa. After internal mixing, the rubber compound is discharged and subjected to a thin pass using an open mill. The thin pass thickness is 2 to 3 mm, and the number of passes is 3 to 4 times to further improve the uniformity of the rubber compound.

[0032] In a more preferred embodiment of the present invention, the compounding agent includes a vulcanizing agent, an accelerator, a reinforcing agent, a softening agent, an antioxidant, and an activator.

[0033] Schematic illustration: Sulfur is selected as the primary vulcanizing agent, with an addition amount of 1.5% to 2.5% of the raw material mass of the rubber compound. Sulfur is chosen as the vulcanizing agent primarily because of its moderate vulcanization efficiency, stable crosslinking effect, and good compatibility with nitrile rubber, which can meet the mechanical performance requirements of the rubber compound components in the working environment of automotive swing arms. Thiazole accelerators, such as 2-mercaptobenzothiazole, are used in combination with sulfenamide accelerators, such as N-cyclohexyl-2-benzothiazole sulfenamide, with a total addition amount of 0.8% to 1.2% of the raw material mass of the rubber compound, wherein the mass ratio of thiazole accelerator to sulfenamide accelerator is 1:1.5. Thiazole accelerators can accelerate the vulcanization reaction rate and shorten the vulcanization time, while sulfenamide accelerators have the characteristic of delaying the initiation of vulcanization, which can prevent early vulcanization of the rubber compound during internal mixing or subsequent processing. When used in combination, the two can ensure the efficiency of the vulcanization reaction and improve the safety and stability of the vulcanization process, ensuring that the rubber compound forms a uniform cross-linked structure during vulcanization molding.

[0034] High-abrasion-resistant carbon black, such as N330 type, is selected as the main reinforcing agent, with an addition amount of 30% to 40% of the raw material weight of the rubber compound. Dioctyl phthalate (DOP) is selected as a softener, with an addition amount of 5% to 8% of the raw material weight of the rubber compound. Dioctyl phthalate has good plasticizing effect, which can reduce the interaction forces between rubber molecules, improve the softness and processing performance of the rubber compound, and make the rubber compound easier to flow and fill the mold cavity during mixing, preforming, and vulcanization, while avoiding cracks caused by excessive hardness during processing. An amine antioxidant, such as N-phenyl-β-naphthylamine, and a phenolic antioxidant, such as 2,6-di-tert-butyl-p-cresol, are compounded, with a total addition amount of 1.0% to 1.5% of the raw material weight of the rubber compound, and a mass ratio of 1:1. Automotive swing arm rubber components are subject to the effects of oxygen, temperature changes, and mechanical stress during use, which can easily lead to aging and degradation, resulting in performance decline. Amine antioxidants offer excellent protection against thermo-oxidative aging and ozone aging, while phenolic antioxidants effectively inhibit thermal aging and fatigue aging of rubber compounds. The combined use of the two can achieve synergistic protection, extend the service life of rubber components, and ensure that they maintain stable performance throughout the vehicle's service life.

[0035] Zinc oxide and stearic acid were selected as activators, with zinc oxide added at 3% to 5% of the raw material mass and stearic acid added at 1% to 2%. Zinc oxide can react with accelerators to generate an active vulcanization accelerator system, increasing the rate and efficiency of the vulcanization reaction, while enhancing the crosslinking density and mechanical properties of the rubber compound. Stearic acid, as a co-activator, can improve the dispersibility of zinc oxide in the rubber compound, further enhancing the activation effect, and also acts as a lubricant, improving the processing fluidity of the rubber compound.

[0036] The specific process for adding compounding agents is as follows: First, the selected qualified nitrile rubber raw materials are put into a mixer for preheating and plasticizing to soften the rubber compound initially; then, the reinforcing agent (high abrasion-resistant carbon black), antioxidant (amine and phenol compound), and zinc oxide from the activator are added, and the mixer is continued for 3 minutes. During this stage, the rotor speed of the mixer is controlled at 40 revolutions per minute, and the temperature is maintained at 80 to 90 degrees Celsius to ensure that the solid compounding agents are evenly dispersed in the rubber compound; next, the softener (dioctyl phthalate) is added, and the mixer is mixed for 2 minutes. The temperature is maintained between 85 and 95 degrees Celsius to allow the liquid compounding agents to fully penetrate into the gaps between rubber molecules, further improving the softness of the rubber compound. Finally, the vulcanizing agent (sulfur), accelerator (thiazole and sulfenamide compound), and stearic acid from the activator are added, and the mixture is continued to be intensively mixed for 2 to 3 minutes. During this stage, the temperature is strictly controlled between 90 and 100 degrees Celsius to avoid premature vulcanization of the rubber compound due to excessive temperature. At the same time, the rotor speed is increased to 50 to 60 revolutions per minute to ensure that the active compounding agents are evenly distributed and form a stable mixing system with the rubber compound.

[0037] The mixing process employs a combination of segmented temperature and pressure control. The first segment maintains a temperature of 80-90 degrees Celsius and a mixing pressure of 0.6 MPa, primarily to ensure uniform dispersion of various compounding agents in the rubber compound and prevent localized aggregation that could negatively impact its performance. The second segment maintains a temperature of 110-120 degrees Celsius and increases the mixing pressure to 0.7-0.8 MPa. In this stage, the synergistic effect of temperature and pressure promotes a preliminary chemical reaction between rubber molecules and compounding agents, laying the foundation for subsequent vulcanization. During the mixing process, a torque sensor in the mixer monitors the viscosity changes of the compound in real time. When the torque value stabilizes within a preset range, such as 30-40 N·m, it indicates that the rubber compound has been uniformly mixed, and the mixing process can be terminated.

[0038] Furthermore, after the internal mixing is completed, the compound is discharged from the internal mixer and immediately fed into an open mill for thin-pass processing. During thin-pass processing, the roll gap of the open mill is adjusted to 2 to 3 mm, the roll temperature is controlled at 60 to 70 degrees Celsius, and the thin-pass process is repeated 3 to 4 times. After each thin-pass process, the rubber compound is folded in half and fed back into the open mill. Through repeated shearing and crushing, the internal agglomeration structure of the rubber compound is further broken down, improving the dispersion uniformity of the compounding agents, and reducing the Mooney viscosity of the rubber compound, making subsequent preforming processes easier. The compounded rubber compound after thin-pass processing needs to be cooled to room temperature and then stored in a dry and ventilated environment for no more than 24 hours to prevent moisture absorption or premature vulcanization, ensuring stable subsequent processing performance.

[0039] Steps 2-3: Pre-forming. Based on the designed shape and dimensions of the molded component, the thinned rubber compound is placed into a pre-forming mold for pre-forming. The pre-forming mold uses a cold-press molding method, controlling the molding pressure at 10 to 15 MPa and the molding time at 2 to 3 minutes. During pre-forming, ensure the rubber compound fills the mold cavity to avoid air bubbles or material shortages. After pre-forming, remove the pre-formed rubber compound from the mold for visual inspection, removing surface impurities and excess rubber. Qualified pre-formed rubber compounds are then transferred to the vulcanization molding process.

[0040] Steps 2-4: Vulcanization. Place the pre-formed rubber compound into the vulcanization mold and vulcanize it using a flat vulcanizing machine. During vulcanization, control the vulcanization temperature at 150-160 degrees Celsius, the vulcanization pressure at 20-25 MPa, and the vulcanization time at 15-20 minutes. The vulcanization time is adjusted according to the thickness of the rubber compound part; for every 1 mm increase in thickness, extend the vulcanization time by 1-2 minutes. After vulcanization, wait for the mold to cool to below 80 degrees Celsius before removing the vulcanized rubber compound part to avoid deformation caused by high temperature removal.

[0041] Steps 2-5: Automated Trimming. A robotic trimming system is used to automatically trim the vulcanized rubber parts, removing burrs and flash from the edges. First, a vision positioning device locates the rubber parts, determining the trimming position and range. Then, based on the positioning results, the robot, carrying a dedicated trimming tool, trims along a preset path. High-speed steel tools are used, with a cutting speed controlled at 200-300 meters per minute and a feed rate of 0.05-0.1 millimeters per revolution. During the trimming process, a dust extraction device promptly removes rubber debris to prevent it from adhering to the part surface. After trimming, a preliminary visual inspection is performed on the parts to ensure there are no residual burrs, flash, or tool scratches. Once qualified, the parts are transferred to the AI ​​automated assembly process.

[0042] Steps 2-6: AI-automated assembly. This involves assembling adhesive components and metal connectors through multi-station collaboration and pre-set assembly logic. Specifically, it includes the following sub-steps: Step 2-6-1: Assembly and Positioning of Workpieces. The trimmed rubber components and pre-sized metal connectors are conveyed to the assembly station via a dedicated conveyor belt system at a speed controlled between 0.5 and 1 meter per minute. A positioning fixture is installed at the assembly station, equipped with multiple positioning pins and clamping devices. After the rubber components and metal connectors are conveyed to the positioning fixture, the clamping devices automatically clamp and fix the workpieces, ensuring that they do not shift during assembly.

[0043] Step 2-6-2: Assembly Sequence Planning and Parameter Presetting. Based on the assembly relationship between the rubber components and metal connectors of the automotive swing arm, the preset assembly sequence is as follows: first install the locating pins, then bond the rubber components to the metal connectors, and finally tighten them. Simultaneously, preset parameters for each assembly action are set, including a locating pin insertion speed of 5 to 10 mm / s and an insertion depth of ±0.01 mm; a bonding pressure of 5 to 8 MPa and a bonding time of 2 to 3 seconds; and a tightening torque of 15 to 20 N·m. These parameters are stored according to the design requirements of different automotive swing arm models, forming a parameter database. During assembly, the corresponding parameters can be automatically retrieved based on the workpiece model.

[0044] The foundation of AI-automated assembly lies in the establishment of an assembly parameter database covering different models of automotive swing arms. This database includes positioning accuracy requirements, assembly sequence logic, and motion parameter standards for various workpieces, such as insertion speed, bonding pressure, and fastening torque. Furthermore, the database is continuously updated and improved based on qualified data collected during the production process. After workpiece loading and positioning is completed in step 2-6-1, the AI ​​system autonomously retrieves the parameter database by reading the workpiece's model identifier (such as a QR code or laser-etched mark) and matches the corresponding assembly parameter combination, eliminating the need for manual input or adjustment. For example, when the conveyed workpiece is a rubber component and metal connector of a swing arm for a compact car model, the AI ​​system can automatically call upon parameters such as a positioning pin insertion speed of 8 mm / s, a bonding pressure of 6 MPa, and a fastening torque of 18 N·m for that model, ensuring the compatibility of assembly parameters for different workpiece models and enabling flexible switching between multiple product types.

[0045] Step 2-6-3: Multi-station collaborative assembly. Three collaborative assembly stations are set up to complete the installation of positioning pins, component fitting, and fastening actions, respectively. The positioned workpieces are transported sequentially to each assembly station via conveyor belt. Each station is equipped with a dedicated assembly robotic arm, and the robotic arms achieve collaborative linkage through signal interaction.

[0046] At the locating pin installation station, the robotic arm grasps the locating pin and inserts it into the locating hole of the rubber component according to preset parameters. After insertion, a pressure sensor detects whether the insertion pressure is within the preset range. If the pressure is abnormal, assembly stops and an alarm signal is issued. At the component bonding station, the robotic arm slowly moves the metal connector closer to the rubber component and completes bonding according to the preset bonding pressure and time. During bonding, a displacement sensor detects the bonding displacement to ensure proper bonding. At the fastening station, the robotic arm carries a torque wrench to complete the fastening action according to the preset fastening torque. After fastening, a torque sensor detects whether the fastening torque is qualified. If it is qualified, it proceeds to the next process; if it is not qualified, it is fastened a second time. If the second fastening is still not qualified, it is judged as a defective assembly.

[0047] In the multi-station collaborative assembly process of step 2-6-3, each assembly station is equipped with a pressure sensor, a displacement sensor, and a torque sensor. The AI ​​system collects the detection data from each sensor in real time and compares it with preset thresholds in the parameter database. For example, at the positioning pin installation station, when the robotic arm inserts the positioning pin, the pressure sensor provides real-time feedback on the insertion pressure data. The AI ​​system compares this data with a preset normal pressure range (e.g., 3-5 MPa): if the data is within the range, the insertion is deemed qualified, and the AI ​​system sends a signal to the conveyor belt to transport the workpiece to the next bonding station; if the data is below 3 MPa, the AI ​​system determines that the insertion is not in place and immediately sends a supplementary insertion signal to the robotic arm, which then performs the insertion action again; if the data is above 5 MPa, the AI ​​system determines that there is a jam, issues an alarm signal, stops the assembly, and records the abnormal data.

[0048] In each assembly stage of steps 2-6-3, the AI ​​system not only collects sensor data in real time but also establishes a database of correspondences between anomaly types and adjustment solutions. Specifically, when the torque sensor at the fastening station detects a fastening torque of 13 N·m (below the preset range of 15-20 N·m), the AI ​​system first identifies the anomaly as insufficient torque. It then autonomously searches the adjustment solution database, determines the adjustment strategy to increase the torque output to 17 N·m, and re-executes the fastening action. If the torque after re-fastening still does not meet the standard, the AI ​​system further searches the solution database, determines that the problem may be a defect in the threads of the metal connector, issues a signal to replace the connector, and controls the feeding mechanism to automatically deliver a new connector, re-executeing the assembly process.

[0049] Step 2-6-4: Initial Fixing After Assembly. After fastening, the workpiece is transported to the initial fixing station, where a temporary fixing device is used to secure the assembled components, preventing loosening or displacement during transfer to the inspection station. The temporary fixing device uses pneumatic clamping with a clamping pressure of 3 to 5 MPa and a clamping time of 1 to 2 minutes. Once the workpiece is stable, the clamping device is released, and the workpiece is transported to the AI ​​vision inspection station.

[0050] Steps 2-7: AI Visual Inspection. This involves detecting assembly quality through multi-angle image acquisition and feature comparison, and coordinating with the assembly process. Specifically, it includes the following sub-steps: Step 2-7-1: Inspection Station Layout and Image Acquisition Device Debugging. Four image acquisition stations are set up to acquire images of the assembled workpiece from four angles: front, back, left, and right. Each acquisition station is equipped with a high-definition industrial camera, lens, and light source. A ring-shaped LED light source is used to ensure uniform illumination of the acquisition area and avoid shadows affecting inspection accuracy. The industrial camera parameters are debugged, including setting the resolution to 2048×1536 pixels, the frame rate to 30 frames per second, and the exposure time to 10 to 20 microseconds, ensuring that the acquired images are clear and detailed.

[0051] Step 2-7-2: Establishing the Inspection Feature Library. Based on the quality standards for automotive swing arm assembly, key inspection features are extracted, including deviations in the installation position of locating pins, the fitting gap between rubber components and metal connectors, and the appearance of fastening parts. By acquiring a large number of multi-angle images of qualified assembled workpieces, these key inspection features are extracted and stored to establish a qualified feature library. Simultaneously, images of various common non-conforming products are collected, and non-conforming features are extracted and a non-conforming feature library is established to provide a basis for subsequent feature comparison.

[0052] Step 2-7-3: Multi-angle Image Acquisition and Preprocessing. The preliminarily fixed workpiece is conveyed to the detection area through the conveyor line, and the industrial cameras at the four image acquisition stations synchronously acquire multi-angle images of the workpiece. After the acquisition is completed, the images are preprocessed. First, grayscale processing is performed to convert the color image into a grayscale image to reduce the amount of data. Then, noise reduction processing is carried out, and the median filter algorithm is used to remove the noise in the image. Finally, image enhancement processing is performed to enhance the contrast of the image and make the detection features clearer.

[0053] Step 2-7-4: Feature Comparison and Quality Judgment. The detection features in the preprocessed multi-angle images are compared with the features in the qualified feature library one by one, and the feature similarity is calculated. If the similarity of all detection features is ≥95%, it is determined that the assembly quality is qualified. If there is a detection feature similarity <95%, the feature is extracted and compared with the unqualified feature library to determine the unqualified type. The specific judgment rules are as follows: If the deviation of the installation position of the positioning pin exceeds ±0.03 mm, it is determined as positioning unqualified; if the fitting gap between the rubber component and the metal connector exceeds 0.1 mm, it is determined as fitting unqualified; if there are scratches, deformations or torque unqualified in the fastening part, it is determined as fastening unqualified.

[0054] Step 2-7-5: Detection Result Feedback and Processing. The detection result is fed back to the control system of the AI automated assembly process in real time. If it is determined as qualified, the workpiece is conveyed to the test station; if it is determined as unqualified, the corresponding adjustment signal is sent according to the unqualified type.

[0055] Among them, when it is positioning unqualified, the control system adjusts the positioning parameters of the positioning tooling and performs positioning and assembly again. When it is fitting unqualified, the fitting pressure and time parameters are adjusted. When it is fastening unqualified, the fastening torque parameters are adjusted. After the adjustment is completed, the unqualified workpiece is reassembled and detected again. If the re-detection is qualified, it enters the test station. If it is still unqualified after three reassemblies and detections, it is determined as a scrap and transferred to the scrap area for processing. At the same time, the unqualified information is recorded in the production management system, including the unqualified type, occurrence time, workpiece model involved, etc., to provide data support for subsequent production optimization.

[0056] After the inspection in step 2-7-5 is completed, the inspection results (pass / fail and the type of failure) will be fed back to the AI ​​automated assembly control system in real time. If a deviation in the installation position of the positioning pin is detected, the AI ​​system will analyze the positioning parameters and detection deviation data of the batch of workpieces and autonomously calculate the adjustment amount: for example, if the actual position of the positioning pin is detected to be 0.02 mm to the left, the AI ​​system will automatically adjust the positioning pin installation reference of the positioning fixture to the left by 0.01 mm and update the parameter database to ensure that the positioning accuracy of subsequent batches of workpieces is corrected; if a large number of defective products with excessive mating gaps are detected (such as 3 consecutive pieces), the AI ​​system will judge that the mating parameters are not suitable enough, and autonomously adjust the mating pressure to the upper middle of the preset range (such as adjusting the original preset 5-8 MPa to 6.5-8 MPa), and record the assembly effect after adjustment. Through the accumulation of data from multiple batches, the parameter settings are gradually optimized to improve the assembly pass rate.

[0057] Steps 2-8: Performance Testing. Workpieces that pass AI vision inspection are transported to the performance testing station to test the mechanical properties and assembly reliability of the rubber components.

[0058] The testing items include the tensile strength, compression set, aging resistance, and connection strength of the assembled components. Tensile strength is tested using a tensile testing machine at a speed of 50 mm / min; compression set is tested using a compression testing machine at a pressure of 10 MPa for 24 hours; aging resistance is tested using an aging chamber at 100°C for 72 hours; and connection strength is tested using a tensile testing machine perpendicular to the connection surface until the components separate, recording the maximum separation force. If all tests meet the design requirements, the product is considered a semi-finished product and transferred to the semi-finished product storage area for later use; if any test item fails, the product is considered defective and transferred to the scrap area.

[0059] It should be noted that the automated trimming, AI-powered automated assembly, and AI-based visual inspection described in step two above have already been successfully implemented in the mass production of automotive rubber components (such as bushings, seals, and shock absorbers). The specific industrial robot hardware and AI system software are not the focus of this invention. Currently, mainstream six-axis industrial robots (such as the ABB IRB 1200 and KUKAKR C4) have achieved a repeatability of ±0.01 mm and a trajectory repeatability of ±0.02 mm, fully meeting the precision requirements for trimming the flash of rubber bushings (the flash width of rubber bushings is typically 0.5-2 mm, with a trimming tolerance of ±0.1 mm). The robot can import the 3D model of the bushing in advance through offline programming (OLP) to plan a continuous cutting path that conforms to the flash contour, with a path resolution of up to 0.01 mm, ensuring that the tool cuts along the flash and avoids damage to the bushing body. In the stage where the visual positioning device determines the trimming position, the collaborative operation of industrial vision systems (such as the Keyence IV2 series and Cognex In-Sight series) and robots is relied upon, which is the standard configuration for current automotive parts processing. The vision system automatically identifies the contour, position, and thickness of the flash by capturing two-dimensional / three-dimensional images of the bushing, and transmits the coordinate data to the robot control system in real time. It performs minor compensation (compensation amount ≤0.05 mm) on the preset path, which can effectively cope with the minor deformation of the bushing after vulcanization molding (usually ≤0.1 mm), and avoid trimming omissions or over-cutting caused by individual differences in workpieces.

[0060] like Figure 4 As shown, step three includes the following steps: Step 3-1: Semi-finished product assembly. The machined semi-finished products prepared in Step 1 and the rubber molding semi-finished products prepared in Step 2 are transported to the finished product assembly station and positioned and assembled using special assembly fixtures.

[0061] First, the machined semi-finished product is fixed to the lower mold of the assembly fixture. Then, a robotic arm picks up the rubber-molded semi-finished product and places it on the machined semi-finished product according to the preset assembly position and orientation. During assembly, the assembly speed is controlled at 10 to 15 millimeters per second to avoid damage to the parts due to excessive speed. After assembly, the two semi-finished products are connected as one unit using bolts. The tightening torque is controlled at 25 to 30 N·m according to design requirements. The tightening sequence is symmetrical to ensure a uniform and firm connection.

[0062] Step 3-2: Post-assembly inspection. A comprehensive inspection is conducted on the assembled automotive control arm, including checks on dimensions, assembly clearances, connection strength, and appearance quality.

[0063] The external dimensions are inspected using a coordinate measuring machine with an accuracy of ±0.01 mm to ensure that all dimensions are within the design tolerance range; the assembly gaps are inspected using feeler gauges, requiring the assembly gaps to be ≤0.1 mm; the connection strength is tested using a tensile testing machine with a sampling ratio of 5% of each batch of products, and the maximum separation force is tested to be ≥5000 N; the appearance quality is inspected using a combination of visual inspection and AI vision inspection to detect defects such as cracks, scratches, deformation, and adhesive peeling on the surface of the finished product.

[0064] If all inspection items pass, the finished product is deemed qualified; if there are any unqualified items, they are marked as unqualified and returned to the semi-finished product assembly process for rework. After rework, they are re-inspected until they pass; if rework is not possible, they are scrapped.

[0065] Step 3-3: Finished Control Arm Warehousing. The inspected and qualified finished automotive control arms are cleaned and rust-proofed. Cleaning is done using ultrasonic cleaning for 5 to 10 minutes to remove oil and impurities from the surface. Rust prevention is achieved by spraying rust-preventive oil to ensure the finished products do not rust during storage. After treatment, the finished products are packaged.

[0066] In the optimal embodiment of this invention, steps one and two are performed in parallel, respectively preparing two types of semi-finished products to provide qualified parts for the final assembly in step three. Within step two, from raw material selection to vulcanization molding into rubber components, automated trimming provides qualified rubber components for assembly. AI-automated assembly assembles the rubber components with metal connectors. AI visual inspection monitors assembly quality in real time and provides feedback for adjustments. Performance testing ensures the usability of the semi-finished rubber components. Each sub-step progresses sequentially, forming a closed-loop production process for the semi-finished rubber components. Within step three, semi-finished product assembly is the core step. Post-assembly inspection provides final control over the quality of the finished product. Only qualified products can be stored; those that fail inspection are reworked, ensuring the quality of products entering the warehouse.

[0067] Figure 5 An automotive lower suspension arm is shown, and the following describes the process of producing the automotive lower suspension arm using the method described in this invention.

[0068] Step 1: Machining and Preparing Semi-finished Metal Body. This step completes the machining of the metal body of the automotive lower suspension arm. Its structure includes bushing mounting holes, connecting holes, load-bearing arms, etc., as detailed below: Blank preparation. High-quality carbon structural steel (No. 45) was selected as the raw material, and the suspension arm blank was formed using a die forging process. The forging temperature was controlled at 1120 degrees Celsius, the forging pressure at 1100 MPa, and the holding time at 38 minutes. After forging, the blank was allowed to cool naturally to room temperature, the surface oxide scale was removed, and after visual inspection to ensure there were no cracks or flash, it was transferred to the machining process.

[0069] Rough machining. Fix the blank in the CNC milling machine fixture and perform the rough machining process: First, rough mill the bearing arm shape of the suspension arm at a cutting speed of 95 m / min, a feed rate of 0.25 mm / revolution, a depth of cut of 4.5 mm, and leave a finishing allowance of 2.5 mm; then rough drill the pre-holes of each connecting hole and bushing mounting hole at a drill speed of 1500 rpm and a feed rate of 0.12 mm / revolution, with the pre-hole diameter being 2 mm smaller than the finished size.

[0070] Finishing. The rough-machined workpiece is transferred to a five-axis machining center for finishing: First, the bushing mounting surface and connecting mating surface of the suspension arm are precision milled at a cutting speed of 140 m / min, a feed rate of 0.1 mm / s, and a depth of cut of 0.8 mm, controlling the flatness of the mating surface to ≤0.03 mm and the surface roughness Ra to ≤0.8 micrometers; then, the bushing mounting hole is precision bored at a boring bar speed of 2000 rpm and a feed rate of 0.08 mm / s, ensuring a hole diameter tolerance of ±0.02 mm and a hole coaxiality of ≤0.01 mm; finally, the connecting hole is precision reamed at a reamer speed of 800 rpm and a feed rate of 0.05 mm / s, ensuring a hole position accuracy of ±0.02 mm.

[0071] Surface treatment. The finished metal body undergoes powder coating: first, degreasing and phosphating pretreatment is performed to remove surface oil and rust; then, an epoxy resin coating is sprayed on, with a coating thickness of 13 micrometers; finally, it is cured at 180 degrees Celsius for 20 minutes to enhance the corrosion resistance of the body.

[0072] Steps 1-5: Semi-finished product inspection. A coordinate measuring machine (CMM) is used to inspect the key dimensions of the main body: the diameter, position, and coaxiality of the bushing mounting holes, and the flatness of the mating surfaces. A hardness tester is used to test the hardness of the main body (HB235). The quality of the coating is visually inspected. If all items pass inspection, the metal main body is considered a semi-finished product and transferred to the semi-finished product storage area for later use. If any items fail inspection, the product is returned to the corresponding machining process for rework; if rework is not possible, it is scrapped.

[0073] Step Two: Rubber Bushing Molding, AI Assembly, and Visual Inspection. This step completes the fabrication of the rubber bushing, as well as the AI-automated assembly and visual inspection of the bushing and the metal body. The specific steps are as follows: Raw material selection for rubber compounds. A blend of natural rubber and nitrile rubber (mass ratio 1:1) was selected as the bushing raw material to meet the cushioning and wear resistance requirements of the suspension arm. The screening criteria included Mooney viscosity of 50 (ML1+4, 100℃), tensile strength ≥19 MPa, elongation at break ≥500%, and impurity content ≤0.4%.

[0074] Step 2-2: Rubber compound internal mixing. Add the blended rubber and compounding agents to the internal mixer in the following proportions: sulfur is used as the vulcanizing agent, with an addition amount of 2.2% of the rubber compound mass; a thiazole and sulfenamide compound is used as the accelerator, with an addition amount of 1.2%; high-abrasion-resistant carbon black N330 is used as the reinforcing agent, with an addition amount of 38%; paraffin oil is used as the softener, with an addition amount of 8%; an amine and phenol compound is used as the antioxidant, with an addition amount of 1.5%; and a zinc oxide and stearic acid compound is used as the activator, with zinc oxide added at 4.5% and stearic acid added at 1.8%.

[0075] Internal mixing process: First, add the blended rubber and preheat and plasticize for 2 minutes at a temperature of 80 degrees Celsius. Then, add carbon black, antioxidant, and zinc oxide and mix for 3 minutes at a temperature of 90 degrees Celsius, with the internal mixer rotor speed at 45 rpm. Next, add paraffin oil and mix for 2 minutes at a temperature of 95 degrees Celsius. Finally, add sulfur, accelerator, and stearic acid and mix for 2.5 minutes at a temperature of 100 degrees Celsius, with the rotor speed at 55 rpm. After internal mixing, the uniformity is judged by torque. When the torque stabilizes at 40 N·m, it indicates that the rubber compound is uniformly mixed. Then, the rubber compound is fed into an open mill for thin-pass processing. The open mill roll gap is adjusted to 2.5 mm, and the thin-pass process is repeated 4 times. After processing, cool to room temperature for later use.

[0076] Pre-forming and vulcanization. The compounded rubber is placed into the bushing pre-forming mold and cold-pressed into a cylindrical structure for the suspension arm bushing. The molding pressure is 14 MPa, and the molding time is 2.5 minutes, ensuring that the rubber fills the cavity without air bubbles. The pre-formed rubber is then placed into the vulcanization mold and vulcanized using a flat vulcanizing machine: the temperature is controlled at 160 degrees Celsius, the pressure is controlled at 24 MPa, and the vulcanization time is 20 minutes. After vulcanization, the mold is allowed to cool to below 70 degrees Celsius before the vulcanized rubber bushing is removed to avoid deformation of the component due to high temperature during removal.

[0077] Automated trimming. A robotic trimming system is used to automatically trim the vulcanized rubber bushings, removing burrs and flash from the edges of the parts. First, a vision positioning device is used to locate the rubber bushing and determine the trimming position and range. Then, an industrial robot, equipped with a high-speed steel cutter, trims the bushing along a preset path, with a cutting speed controlled at 280 meters per minute and a feed rate controlled at 0.08 millimeters per revolution. During the trimming process, a dust extraction device is used to promptly remove rubber debris generated during trimming, preventing debris from adhering to the surface of the parts. After trimming, the parts undergo a preliminary visual inspection to ensure there are no residual burrs, flash, or cutter scratches. Once qualified, the parts are transferred to the AI ​​automated assembly process.

[0078] AI-automated assembly. This step achieves precise assembly of the rubber bushing and the metal body. The specific steps are as follows: Workpiece loading and positioning. The semi-finished metal body and rubber bushing are conveyed to the assembly station via a dedicated loading mechanism. The loading sequence is metal body, then rubber bushing, with a conveying speed controlled at 0.8 meters per minute. The positioning fixture at the assembly station is equipped with positioning pins and a pneumatic clamping device. The metal body is automatically clamped after it reaches its position, with a positioning accuracy controlled at ±0.02 mm. The rubber bushing is picked up by the loading robotic arm and pre-positioned above the bushing mounting holes on the body, aligned with the mounting reference.

[0079] Assembly parameter retrieval. The AI ​​system reads the model identification on the metal body (such as the laser-etched part number), autonomously searches the suspension arm assembly parameter database, and retrieves the parameters for the corresponding model: bushing pressing force is 13.5 MPa, pressing speed is 8 mm / s, and the flatness deviation between the bushing end face and the main body mounting surface after pressing is ≤0.03 mm.

[0080] Multi-station collaborative assembly. Two collaborative stations are set up: Station 1 is for bushing pre-positioning, where a robotic arm drives a positioning rod to insert into the inner hole of the bushing, ensuring that the bushing is coaxial with the mounting hole of the main body; Station 2 is for bushing pressing, where a pressing robotic arm carries a pressing head to press the bushing into the mounting hole of the main body along the coaxial direction. Pressure sensors provide real-time feedback on the pressing force, and displacement sensors simultaneously detect the pressing depth. The AI ​​system compares the real-time data with preset parameters: if the pressing force is within 13.5 MPa and the depth meets the standard, the pressing is deemed qualified, and the conveyor belt is controlled to transport the workpiece to the AI ​​vision inspection station; if the pressing force is lower than 13.5 MPa, the AI ​​system controls the robotic arm to increase the pressing force to 14 MPa and re-press; if the pressing force is higher than 13.5 MPa, it is determined to be an interference with the mounting hole, an alarm is issued, and assembly stops.

[0081] After assembly, auxiliary fixation is performed. After pressing, a pneumatic clamp is used to gently press the end face of the bushing, with the clamping pressure controlled at 4 MPa and the clamping time at 1.5 minutes, to prevent the bushing from loosening during transfer.

[0082] AI visual inspection. This step detects the assembly quality of the bushing and the main body and feeds back to the assembly process. Specific sub-steps include: Inspection station and equipment debugging. Four image acquisition stations are set up (front, back, left, and right). Each acquisition station is equipped with a high-definition industrial camera, lens, and ring LED light source. The industrial camera resolution is set to 2048×1536 pixels, the frame rate is set to 30 frames per second, and the exposure time is set to 15 microseconds to ensure uniform lighting in the acquisition area and clear features such as bushing flatness and hole position deviation.

[0083] Establishment of the detection feature library. According to the qualified standards for the assembly quality of the automotive lower suspension arm, key detection features are extracted: the flatness deviation between the end face of the bushing and the main body mounting surface ≤ 0.03 mm, the clearance between the bushing and the mounting hole ≤ 0.02 mm, and no deformation of the main body connection hole. By collecting multi-angle images of a large number of qualified assembled workpieces, these key detection features are extracted and stored to establish a qualified feature library; at the same time, images of various common unqualified products are collected, unqualified features are extracted, and an unqualified feature library is established to provide a basis for subsequent feature comparison.

[0084] Multi-angle image acquisition and preprocessing. The workpiece after preliminary fixation is conveyed to the detection area through a conveyor line, and industrial cameras at four image acquisition stations synchronously acquire multi-angle images of the workpiece. After the acquisition, the images are preprocessed: first, grayscale processing is performed to convert the color image into a grayscale image to reduce the data volume; then, noise reduction processing is carried out, and the median filter algorithm is used to remove the noise in the image, with the filter window size set to 3×3; finally, image enhancement processing is performed to improve the contrast of the image and make the detection features clearer.

[0085] Feature comparison and determination. The detection features in the preprocessed multi-angle images are compared with the features in the qualified feature library one by one, and the feature similarity is calculated. If the similarity of all detection features is ≥ 95%, it is determined that the assembly quality is qualified; if there is a detection feature similarity < 95%, then this feature is extracted and compared with the unqualified feature library to determine the unqualified type: if the flatness deviation between the end face of the bushing and the main body mounting surface exceeds 0.03 mm, it is determined that the flatness is unqualified; if the clearance between the bushing and the mounting hole exceeds 0.02 mm, it is determined that the clearance exceeds the standard; if the main body connection hole is deformed, it is determined that the hole position is deformed.

[0086] Result feedback and processing. The detection results are real-time feedback to the control system of the AI automated assembly process: if it is determined to be qualified, the workpiece is conveyed to the test station; if it is determined to be unqualified, corresponding adjustment signals are sent according to the unqualified type: when the flatness is unqualified, adjust the alignment angle of the positioning tooling; when the clearance exceeds the standard, adjust the pressing force to 14 MPa; when the hole position is deformed, feedback to the machining process in step one to correct the drilling parameters. After the adjustment, the unqualified workpieces are reassembled and detected again. If the re-detection is qualified, they enter the test station; if they are still unqualified after three re-assemblies and detections, they are determined to be scrap products and transferred to the scrap area for processing. At the same time, the unqualified information is recorded in the production management system, including the unqualified type, occurrence time, workpiece model involved, etc., to provide data support for subsequent production optimization.

[0087] Performance testing. The workpieces qualified by AI vision detection are conveyed to the performance test station to test the mechanical properties and assembly reliability of the rubber bushings. The testing process will not be elaborated here.

[0088] Finally, the finished product is assembled and put into storage.

[0089] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0090] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for producing an automotive swing arm, characterized in that, Includes the following steps: Step 1: Preparation of semi-finished products by machining. The process involves blank preparation, rough machining, fine machining, drilling, and semi-finished product inspection to obtain semi-finished products by machining. Step 2: Preparation of semi-finished rubber molding products. The process involves raw material screening, rubber mixing, pre-forming, vulcanization molding, automated trimming, AI automated assembly, AI visual inspection and performance testing to obtain semi-finished rubber molding products. Step 3: Finished product assembly and warehousing, which involves semi-finished product assembly, post-assembly inspection, and warehousing of the finished swing arm. Step one and step two are carried out in parallel. The results of the AI ​​visual inspection in step two are fed back to the AI ​​automated assembly process in real time to adjust the assembly parameters.

2. The method for producing an automotive swing arm according to claim 1, characterized in that, Step one includes the following steps: Step 1-1: Blank preparation: Select raw materials and form them using a die forging process. After cooling, the blank is obtained. Steps 1-2: Rough machining, rough machining of the blank's outer diameter, end face and steps, leaving machining allowance; Steps 1-3: Machining and finishing, performing finishing on key mating surfaces and mounting hole positioning surfaces of the workpiece after rough machining; Steps 1-4: Drilling, drilling holes in the finished workpiece and then reaming and deburring. Steps 1-5: Semi-finished product inspection. A comprehensive inspection is carried out on the workpiece after drilling. If it passes the inspection, a semi-finished machined product is obtained.

3. The method for producing an automotive swing arm according to claim 2, characterized in that, Step two includes the following steps: Step 2-1: Raw material screening, the raw materials for rubber compound are tested and screened according to their indicators; Step 2-2: Rubber compound internal mixing. The rubber raw materials and compounding agents are put into the internal mixer in proportion and mixed in stages with controlled temperature. After passing through the open mill, the mixture is cooled and stored. Steps 2-3: Pre-forming, the thinned rubber material is placed into the pre-forming mold for cold pressing and then visual inspection is performed; Steps 2-4: Vulcanization molding. Place the pre-formed rubber compound into the vulcanization mold and vulcanize it using a flat vulcanizing machine. After cooling, remove the rubber compound parts. Steps 2-5: Automated trimming, using a robotic trimming system to remove burrs and flash from the rubber parts; Steps 2-6: AI-automated assembly, which achieves the assembly of adhesive components and metal connectors through multi-station collaboration; Steps 2-7: AI visual inspection, which involves acquiring multi-angle images and comparing features of the assembled workpiece, and providing feedback on the inspection results; Steps 2-8: Performance testing. Mechanical properties and assembly reliability tests are conducted on the workpieces that pass the AI ​​vision inspection. After passing the tests, the semi-finished product with rubber molding is obtained.

4. The method for producing an automotive swing arm according to claim 3, characterized in that, The raw material for the rubber compound in step 2-1 is nitrile rubber or a blend of natural rubber and nitrile rubber.

5. The method for producing an automotive swing arm according to claim 4, characterized in that, The compounding agents in step 2-2 include vulcanizing agents, accelerators, reinforcing agents, softeners, antioxidants, and activators. The temperature of the first stage of internal mixing is controlled at 80 to 90 degrees Celsius, and the mixing time is 3 to 4 minutes. The temperature of the second stage is controlled at 110 to 120 degrees Celsius, and the mixing time is 2 to 3 minutes. The rotor speed of the internal mixer is 40 to 60 revolutions per minute, the mixing pressure is 0.6 to 0.8 MPa, the thin pass thickness of the open mill is 2 to 3 mm, and the number of thin passes is 3 to 4.

6. The method for producing an automotive swing arm according to claim 5, characterized in that, The vulcanizing agent is sulfur, and its addition amount is 1.5% to 2.5% of the mass of the rubber raw materials; the accelerator is a compound of thiazole accelerator and sulfenamide accelerator, with a mass ratio of thiazole accelerator to sulfenamide accelerator of 1:1.5, and the total addition amount is 0.8% to 1.2% of the mass of the rubber raw materials; the reinforcing agent is N330 high abrasion-resistant carbon black, and its addition amount is 30% to 40% of the mass of the rubber raw materials; the softening agent is phthalic acid. Dioctyl formate is added at a rate of 5% to 8% of the mass of the rubber raw materials; the activator is a compound of zinc oxide and stearic acid, wherein the amount of zinc oxide added is 3% to 5% of the mass of the rubber raw materials, and the amount of stearic acid added is 1% to 2% of the mass of the rubber raw materials; the antioxidant is a compound of amine antioxidant and phenolic antioxidant, wherein the mass ratio of amine antioxidant to phenolic antioxidant is 1:1, and the total amount added is 1.0% to 1.5% of the mass of the rubber raw materials.

7. The method for producing an automotive swing arm according to claim 6, characterized in that, The process of adding compounding agents in step 2-2 is as follows: First, put the rubber raw materials into a mixer for preheating and plasticizing; then add zinc oxide from the reinforcing agent, antioxidant, and activator, and mix for 3 minutes at 80 to 90 degrees Celsius and a rotor speed of 40 revolutions per minute; next, add the softener and mix for 2 minutes at 85 to 95 degrees Celsius; finally, add stearic acid from the vulcanizing agent, accelerator, and activator, and mix for 2 to 3 minutes at 90 to 100 degrees Celsius and a rotor speed of 50 to 60 revolutions per minute.

8. The method for producing an automotive swing arm according to claim 7, characterized in that, In step 2-2, the viscosity change of the compound is monitored in real time by the torque sensor of the internal mixer. When the torque value stabilizes at 30 to 40 N·m, the internal mixing process ends. The roller temperature is controlled at 60 to 70 degrees Celsius during the thin pass of the open mill. After the thin pass, the rubber compound is cooled to room temperature and stored for no more than 24 hours.

9. The method for producing an automotive swing arm according to claim 8, characterized in that, In steps 2-3, the pre-forming pressure is 10 to 15 MPa, and the forming time is 2 to 3 minutes.

10. The method for producing an automotive swing arm according to claim 9, characterized in that, In steps 2-4, the vulcanization temperature is 150 to 160 degrees Celsius, the vulcanization pressure is 20 to 25 MPa, and the vulcanization time is 15 to 20 minutes. The vulcanization time is adjusted according to the thickness of the rubber part. For every 1 mm increase in thickness, the vulcanization time is extended by 1 to 2 minutes. After the mold cools to below 80 degrees Celsius, the rubber part is removed.

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