Machining method of integrated metal automobile wheel

Abstract

The invention discloses a machining method for an integrated metal automobile wheel, and relates to the technical field of the automobile industry. The machining method comprises the steps that S1, blanking is conducted, and a round metal blank is obtained; s2, multi-pass profiling is carried out, and a bidirectional taper material, an accurate angle material and an inwards-concave spoke plane are sequentially formed through three-time profiling procedures; s3, a reference system is prepared, and a center positioning hole and an asymmetric process pin hole are synchronously machined in one-time punching; s4, rim preforming is conducted, and rim protrusions are machined by adopting a shoveling and rotating technology on the basis of reference positioning; s5, rim final forming is conducted, specifically, the protrusions are formed into rims through rolling; s6, performance regulation and control spinning is conducted, specifically, the center of the spoke is rolled and strengthened, and directional wall thickness reduction is conducted on the rim; and S7, all machining is completed on the same standard. By means of the method, real weldless integrated forming can be achieved, production is simplified, and accurate standard unification, active performance regulation and control and reasonable material distribution can be achieved in the whole technological process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile industry, and particularly relates to a processing method of an integrated metal automobile wheel. BACKGROUND

[0002] In the field of automobile industry, as a key safety component, the manufacturing process of the wheel is directly related to the driving safety and overall performance of the vehicle. At present, the mainstream manufacturing method of automobile steel wheels is to process the spokes and the rim as two independent parts respectively, and then combine them into a whole through welding process. Although this process route of separate manufacturing and welding is mature and widely used, it has some inherent drawbacks. First, the welding process forms a closed annular weld at the connection between the spoke and the rim, which is prone to become a stress concentration point. Under the action of long-term complex alternating load, fatigue cracks may occur, which poses a potential safety risk. Second, this process requires the establishment of two independent production lines for the spoke and the rim, as well as an assembly and welding line, which requires a large investment in equipment, occupies a large area, has a long production process, and consumes a lot of energy. At the same time, it involves welding operations, which puts higher requirements on the production environment and management. In addition, the problems of product qualification rate caused by the variety of materials, increased logistics cost and welding quality fluctuations cannot be ignored due to separate manufacturing. Therefore, the industry has been exploring technical solutions to realize the integrated forming of the wheel, in order to fundamentally eliminate the weld hidden danger, simplify the production process, and improve the consistency and reliability of the product.

[0003] However, the existing integrated forming technology, such as single spinning or profiling process, although can realize the integrity of the structure, still faces challenges in actual application. On the one hand, the simple integrated forming process is not accurate enough in controlling the material flow, wall thickness distribution and forming of key parts such as the center of the spoke and the rim, which may lead to insufficient local strength or redundant weight of the product, making it difficult to balance lightweight and high strength, high rigidity requirements; on the other hand, the entire manufacturing process involves multiple processes, and if there is no unified, precise and error-proof positioning reference system, cumulative errors may easily occur during process conversion, seriously affecting the dimensional accuracy of the final product, especially the positioning accuracy of the bolt circle diameter (PCD) and the center hole, and further affecting the dynamic balance performance and installation precision of the wheel. At the same time, how to actively intervene and optimize the material organization and performance of the key parts of the wheel while ensuring efficient production, and realize equal strength design, is also a problem that the existing process has not been able to solve well.

[0004] Therefore, how to develop a processing method for integrated metal automobile wheels that can not only achieve true seamless integrated molding and simplify production, but also achieve precise benchmark unification, proactive performance control and reasonable material distribution throughout the entire process, thereby further improving the overall performance and manufacturing efficiency of the product while ensuring structural safety and reliability, has become a technical problem that urgently needs to be solved by people in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a processing method for integrated metal automobile wheels, which not only achieves true seamless integrated molding and simplifies production, but also enables precise benchmark unification, proactive performance control, and reasonable material distribution throughout the entire process. This further improves the overall performance and manufacturing efficiency of the product while ensuring structural safety and reliability.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: This invention discloses a method for processing an integrated metal automobile wheel, comprising the following steps: S1. Blanking: Obtaining a round metal billet; S2, Multi-channel Sub-pressure Type: S21. First pressing: The blank is pressed using a press with a tapered shrinking pressing mold, so that the upper cylinder wall is inclined inward at 25-60 degrees and the lower cylinder wall is inclined outward at 25-60 degrees to obtain a preliminary tapered material; S22. Second pressing: The initial conical material is pressed again to increase the inward tilt angle of its upper part to 50-90 degrees, resulting in a secondary conical material; S23. Spoke preforming: The top of the secondary conical material is pressed to form a spoke plane with an inward concavity of 10°-15° and an inward concavity depth of 30-45mm; S3. Reference system preparation: After the multi-pass pressing, a composite mold is used to press the formed blank once, and the center positioning hole and several asymmetrically distributed process pin holes are processed simultaneously to form a unique, error-proof reference system. S4. Rim preforming: After the reference system is prepared, it is positioned by combining the central positioning hole and the process pin hole. A raised ring is machined on the rim part of the blank using a shovel-turning process. This raised ring serves as the preforming part of the rim. S5. Final forming of the rim: The blank with the protrusions obtained in step S4 is rolled to form the protrusions into a rim. S6. Performance-Controlled Spinning: The blank from step S5 is clamped in a spinning machine and positioned using the central positioning hole and process pin hole for spinning. During this stage, the path and pressure of the spinning wheel are controlled by a CNC program to achieve at least one of the following objectives: (a) The central area of ​​the wheel spokes of the billet is locally and repeatedly rolled to densify the material and refine the grains in that area; (b) Directional and unequal thickness reduction is performed on different parts of the rim so that the wall thickness of non-critical stress areas is reduced to achieve weight reduction, while the wall thickness of critical stress areas that cooperate with the tire is maintained or increased. S7. Machining: In subsequent turning, milling, drilling, and reaming processes, the central positioning hole and process pin hole are always used for combined positioning to machine the wheel's center hole, bolt hole, air hole, and valve core hole.

[0007] Preferably, in the performance-controlled spinning process described in step S6, a high-frequency induction heating device is integrated, which is configured to perform instantaneous and precise heating only in the local area in front of the spinning wheel where plastic deformation is about to occur.

[0008] Preferably, the high-frequency induction heating device includes a high-frequency induction generator, an induction coil connected to the generator, and a control unit for controlling and adjusting heating parameters; the induction coil is installed in front of the spinning wheel of the spinning machine, and its position and angle are configured to match the movement path of the spinning wheel to ensure that the narrow strip area about to be deformed is heated through heating in a very short time before the spinning wheel contacts the workpiece.

[0009] Preferably, the heating temperature of the high-frequency induction heating is controlled within a range that significantly improves the plasticity of the material but is below its recrystallization temperature, and the workpiece body is kept at a low temperature.

[0010] Preferably, in step S3, the number of asymmetrically distributed process pin holes is set to three or four.

[0011] Preferably, in steps S21 and S22, the pressure of the molding process is set to 10-20 MPa, and the molding speed is set to 33-60 mm / s.

[0012] Preferably, in step S4, the shovel wheel used in the shovel-spinning process has a working surface shape that is adapted to the cross-sectional shape of the protruding target.

[0013] Preferably, in step S6, the key stress-bearing area includes the bead seat and the root of the rim.

[0014] Preferably, the circular metal billet is made of steel.

[0015] Compared with the prior art, the beneficial technical effects of the present invention are as follows: 1) This invention uses a wheel rim forming process that combines multi-stage pressing with shovel spinning and rolling. It also innovatively processes a unified reference system with error prevention function on a stable semi-finished product in one go. This ensures that all processes from wheel rim pre-forming to final machining are based on the same reference positioning, completely eliminating the cumulative error caused by reference conversion. This results in extremely high positional accuracy for key wheel dimensions such as bolt hole distribution circle and center hole, thereby ensuring excellent dynamic balance performance and installation reliability of the product. At the same time, the error prevention design effectively avoids manual clamping errors and improves the consistency and efficiency of mass production. 2) After the rim is finally shaped, this invention introduces a CNC performance-controlled spinning process integrating a high-frequency induction heating device. This device can instantly and accurately heat the narrow deformation zone in front of the spinning wheel, significantly reducing the material deformation resistance and equipment load. On this basis, the center of the spoke is repeatedly rolled by a CNC program to achieve grain refinement and microstructure densification, and directional wall thickness reduction is implemented in different parts of the rim to achieve the same strength design of the wheel. This not only significantly improves the load-bearing strength and fatigue resistance of the spoke mounting surface, but also effectively reduces the overall weight of the wheel while ensuring the safe thickness of key stress areas such as the bead seat, achieving a unity of high strength and lightweight. 3) This invention revolutionizes the traditional wheel manufacturing process. Through a complete and collaborative process chain, including multi-stage pressing, standardized manufacturing, pre-forming by shovel spinning, final forming by roll forming, and performance-controlled spinning, it successfully manufactures seamless, integrated steel wheels. This fundamentally eliminates potential safety hazards such as cracks and stress concentration caused by welding. At the same time, the method is compact, reducing equipment investment and space occupation. Through proactive material performance control and precise forming control, the final product has comprehensive advantages such as structural integrity, safety and reliability, lighter weight, and longer lifespan, thus comprehensively enhancing the product's market competitiveness. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings.

[0017] Figure 1 This is a process flow diagram of a method for processing an integrated metal automobile wheel according to the present invention. Detailed Implementation

[0018] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present 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 only used to explain the present invention and are not intended to limit the present invention.

[0019] like Figure 1 As shown, a method for processing an integrated metal automobile wheel includes the following steps: S1. Blanking: Obtaining a round metal billet; S2, Multi-channel Sub-pressure Type: S21. First pressing: The blank is pressed using a press with a tapered shrinking pressing mold, so that the upper cylinder wall is inclined inward at 25-60 degrees and the lower cylinder wall is inclined outward at 25-60 degrees to obtain a preliminary tapered material; S22. Second pressing: The initial conical material is pressed again to increase the inward tilt angle of its upper part to 50-90 degrees, resulting in a secondary conical material; S23. Spoke preforming: The top of the secondary conical material is pressed to form a spoke plane with an inward concavity of 10°-15° and an inward concavity depth of 30-45mm; Specifically, the multi-stage pressing process is carried out in stages on a hydraulic press. The first pressing uses an initial tapered mold to form a circular blank into a preliminary tapered material with an inclination angle of 25-60 degrees on both the upper and lower cylinder walls, forming a transitional shape with bidirectional tapering. The second pressing uses a final tapered mold to increase the inclination angle of the upper cylinder wall to 50-90 degrees, making it closer to the final geometric contour of the wheel spoke. The pre-forming pressing of the wheel spoke uses a flat mold with a boss to press a wheel spoke plane with a depth of 30-45mm and an inward concavity of 10-15 degrees on the top of the secondary tapered material. This inward concavity design is intended to actively compensate for material springback. After unloading, the springback effect causes the wheel spoke plane to return to the required design flatness, thereby ensuring its fitting accuracy with the axle mounting surface and its service reliability.

[0020] S3. Reference system preparation: After the multi-pass pressing, a composite mold is used to press the formed blank once, and the center positioning hole and several asymmetrically distributed process pin holes are processed simultaneously to form a unique, error-proof reference system. Specifically, the datum system is prepared on a semi-finished product with a stable workpiece geometry after multiple pressing passes. A composite mold is used to simultaneously process the central positioning hole and several asymmetrically distributed process pin holes in a single pressing stroke of the hydraulic press. This single-press process eliminates the cumulative errors caused by multiple clamping and datum conversions. Simultaneously, the asymmetrically distributed process pin holes constitute a fault-prevention datum, ensuring that the workpiece has a unique and definite positioning orientation in the fixtures of all subsequent processes, effectively preventing misoperation and ensuring dimensional consistency in mass production.

[0021] S4. Rim preforming: After the reference system is prepared, it is positioned by combining the central positioning hole and the process pin hole. A raised ring is machined on the rim part of the blank using a shovel-turning process. This raised ring serves as the preforming part of the rim. Specifically, the rim preforming process is carried out on a rotary wheel, where the workpiece is precisely positioned using a reference system formed by the central positioning hole and the process pin hole. The rotary wheel used has a working surface profile designed and manufactured according to the target cross-sectional shape of the rim preforming protrusion. During the workpiece rotation, the rotary wheel feeds along a predetermined path, and its profile extrudes and guides the metal in the rim area, thereby forming a continuous and uniform annular protrusion. This protrusion, as the preforming part of the rim, reserves a precise material volume for subsequent final forming and optimizes the metal flow lines, which helps to improve the microstructure density and mechanical properties of the final formed rim.

[0022] S5. Final forming of the rim: The blank with the protrusions obtained in step S4 is rolled to form the protrusions into a rim. Specifically, the final forming of the rim is achieved through a rolling mill. The workpiece with pre-formed protrusions is placed in a rolling die, and under the action of rolling pressure, the metal in the protrusions undergoes plastic flow and completely fills the rim cavity, ultimately obtaining a rim with precise dimensions and a smooth surface. Setting this process before performance-controlled spinning ensures that the final geometry of this critical feature of the rim is not affected by deformation that may occur in subsequent spinning processes, guaranteeing the stability and consistency of the product shape.

[0023] S6. Performance-Controlled Spinning: The blank from step S5 is clamped in a spinning machine and positioned using the central positioning hole and process pin hole for spinning. During this stage, the path and pressure of the spinning wheel are controlled by a CNC program to achieve at least one of the following objectives: (a) The central area of ​​the wheel spokes of the billet is locally and repeatedly rolled to densify the material and refine the grains in that area; (b) Directional and unequal thickness reduction is performed on different parts of the rim so that the wall thickness of non-critical stress areas is reduced to achieve weight reduction, while the wall thickness of critical stress areas that cooperate with the tire is maintained or increased. Specifically, the performance-controlled spinning process is performed on a CNC spinning machine, with the workpiece clamped in the spinning machine mandrel via the aforementioned reference system. This process precisely controls the movement trajectory and applied pressure of the spinning wheels through a CNC program to achieve a dual purpose: Firstly, localized and repeated rolling of the central area of ​​the wheel spokes leads to the refinement of metal grains and densification of the microstructure in that area, significantly improving its load-bearing strength and fatigue durability. Secondly, directional wall thickness reduction is implemented in different parts of the rim, that is, the wall thickness is reduced in non-critical stress areas to achieve weight reduction, while the wall thickness is maintained or increased in critical stress areas such as the bead seat, thereby achieving the same strength design of the wheel.

[0024] S7. Machining: In subsequent turning, milling, drilling, and reaming processes, the central positioning hole and process pin hole are always used for combined positioning to machine the wheel's center hole, bolt hole, air hole, and valve core hole.

[0025] Specifically, subsequent machining processes, including turning the center hole, drilling bolt holes and air holes, and milling valve holes, are all strictly positioned using the same reference system established in step S3. This principle of "unified reference" is applied throughout, eliminating positioning errors caused by reference conversion between processes, and especially ensuring the machining accuracy of key dimensions such as the bolt hole distribution circle (PCD), thereby ensuring the dynamic balance performance and installation reliability of the wheel.

[0026] Specifically, in the performance-controlled spinning process described in step S6, a high-frequency induction heating device is integrated. The high-frequency induction heating device is configured to perform instantaneous and precise heating only in the local area in front of the spinning wheel where plastic deformation is about to occur.

[0027] Specifically, the high-frequency induction heating device includes a high-frequency induction generator, an induction coil connected to the generator, and a control unit for controlling and adjusting heating parameters; the induction coil is installed in front of the spinning wheel of the spinning machine, and its position and angle are configured to match the movement path of the spinning wheel to ensure that the narrow strip area about to be deformed is heated through heating in a very short time before the spinning wheel contacts the workpiece.

[0028] Specifically, the heating temperature of the high-frequency induction heating is controlled within a range that significantly improves the plasticity of the material but is below its recrystallization temperature, while the main body of the workpiece remains at a low temperature.

[0029] Specifically, the performance-controlled spinning process integrates a high-frequency induction heating device, which consists of a high-frequency induction generator, a circulating cooling system, an induction coil, and a PLC control unit. The induction coil is mounted in front of the spinning machine's rotating wheel via a rigid bracket, its spatial position coordinated with the wheel's movement path. The PLC control unit controls the induction coil to perform through-heating induction heating only on the narrow strip-shaped area in front of the rotating wheel that is about to undergo plastic deformation, for a very short time before the rotating wheel presses against the workpiece. For steel, the heating temperature is controlled within a range that significantly improves its plasticity but remains below the recrystallization temperature (typically 500-700℃), while the main body of the workpiece remains at a low temperature. This localized heating method significantly reduces the material's deformation resistance, decreases the load and energy consumption of the spinning equipment, and avoids material deterioration problems such as oxidation and grain coarsening caused by overall workpiece heating.

[0030] Specifically, in step S3, the number of asymmetrically distributed process pin holes is set to three or four.

[0031] Specifically, three pin holes form an asymmetrical triangular reference, while four pin holes form an irregular quadrilateral reference. This asymmetrical layout is the core of the error-proofing function. It restricts the workpiece's degrees of freedom in the fixture, ensuring that it can only be installed and positioned in a single correct posture, thus providing a foundation for the precision and reliability of automated production.

[0032] Specifically, in steps S21 and S22, the pressure of the molding process is set to 10-20 MPa, and the molding speed is set to 33-60 mm / s.

[0033] Specifically, this parameter combination ensures that the metal billet can undergo sufficient and uniform plastic flow during the forming process, while effectively suppressing the risk of local tearing caused by pressure overload, as well as impact scratches and internal damage caused by excessive speed, providing dimensionally stable and reliable intermediate products for subsequent processes.

[0034] Specifically, in step S4, the shovel wheel used in the shovel-spinning process has a working surface shape that is adapted to the cross-sectional shape of the protruding target.

[0035] Specifically, in step S6, the key stress-bearing areas include the bead seat and the root of the rim.

[0036] Specifically, in the directional thinning design of step S6, the bead seat and rim root of the rim are clearly defined as critical stress areas. These parts directly bear the inflation pressure, lateral force, and complex alternating loads transmitted by the tire. By actively controlling the wall thickness of these areas through the spinning process, it is essentially a structural reinforcement of the weakest link under the service conditions of the wheel, thereby significantly improving the fatigue life and safety of the product.

[0037] Specifically, the circular metal billet is made of steel.

[0038] Specifically, the method of this invention is preferably applied to the processing of steel, wherein the circular metal billet is standard wheel steel. Steel possesses excellent strength, plasticity, and fatigue properties, and is highly compatible with the multi-pass forming, spun, and performance-controlled spinning processes involved in this method. The integrated steel wheel manufactured by this method not only eliminates the potential weld defects inherent in traditional welding processes, but also optimizes material properties through proactive performance control processes, achieving the comprehensive goals of high structural strength, high safety and reliability, and lightweight design.

[0039] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do 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 process, method, article, or apparatus.

[0040] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for processing an integrated metal automobile wheel, characterized in that, Includes the following steps: S1. Blanking: Obtaining a round metal billet; S2, Multi-channel Sub-pressure Type: S21. First pressing: The blank is pressed using a press with a tapered shrinking pressing mold, so that the upper cylinder wall is inclined inward at 25-60 degrees and the lower cylinder wall is inclined outward at 25-60 degrees to obtain a preliminary tapered material; S22. Second pressing: The initial conical material is pressed again to increase the inward tilt angle of its upper part to 50-90 degrees, resulting in a secondary conical material; S23. Spoke preforming: The top of the secondary conical material is pressed to form a spoke plane with an inward concavity of 10°-15° and an inward concavity depth of 30-45mm; S3. Preparation of reference system: After the multi-pass pressing, the formed blank is stamped once using a composite mold to simultaneously process the central positioning hole and several asymmetrically distributed process pin holes, which together constitute a unique, error-proof reference system. S4. Rim preforming: After the reference system is prepared, it is positioned by combining the central positioning hole and the process pin hole. A raised ring is machined on the rim part of the blank using a shovel-turning process. This raised ring serves as the preforming part of the rim. S5. Final forming of the rim: The blank with the protrusions obtained in step S4 is rolled to form the protrusions into a rim. S6. Performance-Controlled Spinning: The blank from step S5 is clamped in a spinning machine and positioned using the central positioning hole and process pin hole for spinning. During this stage, the path and pressure of the spinning wheel are controlled by a CNC program to achieve at least one of the following objectives: (a) The central area of ​​the wheel spokes of the billet is locally and repeatedly rolled to densify the material and refine the grains in that area; (b) Directional and unequal thickness reduction is performed on different parts of the rim so that the wall thickness of non-critical stress areas is reduced to achieve weight reduction, while the wall thickness of critical stress areas that cooperate with the tire is maintained or increased. S7. Machining: In subsequent turning, milling, drilling, and reaming processes, the central positioning hole and process pin hole are always used for combined positioning to machine the wheel's center hole, bolt hole, air hole, and valve core hole.

2. The processing method for an integrated metal automobile wheel according to claim 1, characterized in that: In the performance-controlled spinning process described in step S6, a high-frequency induction heating device is integrated. The high-frequency induction heating device is configured to perform instantaneous and precise heating only in the local area in front of the spinning wheel where plastic deformation is about to occur.

3. The processing method for an integrated metal automobile wheel according to claim 2, characterized in that: The high-frequency induction heating device includes a high-frequency induction generator, an induction coil connected to the generator, and a control unit for controlling and adjusting heating parameters. The induction coil is installed in front of the spinning wheel of the spinning machine, and its position and angle are configured to match the movement path of the spinning wheel to ensure that the narrow strip area about to be deformed is heated through heating in a very short time before the spinning wheel contacts the workpiece.

4. The processing method for an integrated metal automobile wheel according to claim 3, characterized in that: The heating temperature of the high-frequency induction heating is controlled within a range that significantly improves the plasticity of the material but is below its recrystallization temperature, while the main body of the workpiece remains at a low temperature.

5. The processing method for an integrated metal automobile wheel according to claim 1, characterized in that: In step S3, the number of asymmetrically distributed process pin holes is set to three or four.

6. The processing method for an integrated metal automobile wheel according to claim 1, characterized in that: In steps S21 and S22, the pressure for the molding process is set to 10-20 MPa, and the molding speed is set to 33-60 mm / s.

7. The processing method for an integrated metal automobile wheel according to claim 1, characterized in that: In step S4, the shovel wheel used in the shovel-spinning process has a working surface shape that is adapted to the cross-sectional shape of the protruding target.

8. The processing method for an integrated metal automobile wheel according to claim 1, characterized in that: In step S6, the key stress-bearing areas include the bead seat and the root of the rim.

9. The processing method for an integrated metal automobile wheel according to claim 1, characterized in that: The circular metal billet is made of steel.

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