A high-power extrusion plastic molding equipment and method

Abstract

A high-power extrusion plastic molding equipment and method are suitable for moldless molding of billets. The equipment includes: a main shaft drive unit for driving the billet to rotate; an outer extrusion roller group including at least one outer roller for extruding the outer side of the billet; an inner forming roller group including at least one inner roller for supporting the inner side of the billet; a drive unit for driving the outer extrusion roller group and the inner forming roller group to feed along the axial and / or radial direction of the billet; and a flexible clamping unit disposed on the main shaft drive unit for clamping the billet. The correspondingly arranged outer and inner rollers constitute a roller forming unit. The method includes: a clamping and alignment step, a trajectory planning step, a rotation drive step, and a synchronous extrusion step. During the rotation of the billet, the drive unit drives the outer extrusion roller group and the inner forming roller group to move synchronously along a planned cooperative motion trajectory, performing continuous and symmetrical radial extrusion and axial elongation operations on the billet until molding is completed.

Description

Technical Field

[0001] This invention relates to metal plastic forming technology, and more specifically, to a high-power extrusion plastic forming equipment and method, particularly suitable for spinning aluminum alloy wheels, for manufacturing axisymmetric thin-walled rotating parts. Background Technology

[0002] Spinning is a common process for manufacturing thin-walled rotating parts (such as wheel rims, end caps, cylinders, cones, etc.). Traditional mandrel spinning, especially high-intensity spinning, relies on a mandrel (die) that matches the shape of the product's internal cavity to support and define the final shape of the workpiece. The blank is pressed onto the mandrel and rotates with it. A spinning wheel applies pressure to the blank along a preset trajectory, causing it to conform to the mandrel and be formed.

[0003] However, this die-spinning process has significant drawbacks:

[0004] 1) High mold costs: Each product requires a dedicated core mold, which results in long design and manufacturing cycles and high costs;

[0005] 2) Poor production flexibility: Changing products means changing molds, which takes a long time to adjust and makes it difficult to adapt to the production needs of multiple varieties and small batches;

[0006] 3) Limited applicability: For parts with complex internal cavities or variable cross-sections, mandrel manufacturing is difficult or even impossible;

[0007] 4) The process is highly dependent on the blank: In order to ensure the consistency of spinning, the blank needs to be dimensionally consistent. At the same time, it depends on the matching of the blank and the core mold for shaping, and the positioning accuracy requirement is high.

[0008] Currently, no effective solutions have been proposed for these technical problems. To overcome the problems of high cost, poor flexibility, and low efficiency of existing spinning dies, it is desirable to provide a technical solution with high molding accuracy and good production flexibility.

[0009] The information in this background section is intended only to enhance the understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0010] To solve the above-mentioned technical problems, the purpose of this invention is to provide a high-power extrusion plastic molding equipment and method, which has an automatic alignment function and can perform moldless plastic molding on blanks for manufacturing axisymmetric thin-walled rotating parts.

[0011] According to one aspect of the present invention, a high-power extrusion plastic forming apparatus is provided for moldless plastic forming of a billet, comprising: a main shaft drive unit for driving the billet to rotate with a main shaft; an outer extrusion roller group including at least one outer roller for extruding the outer side of the billet; an inner forming roller group including at least one inner roller for supporting the inner side of the billet; a drive unit for correspondingly driving the outer extrusion roller group and the inner forming roller group to feed along the axial and / or radial direction of the billet; and a flexible clamping unit disposed on the main shaft drive unit for clamping billets of different sizes, wherein the correspondingly arranged outer roller and inner roller constitute a roller forming unit.

[0012] Preferably, the roller forming unit, consisting of an outer extrusion roller group and an inner forming roller group, includes: a first pair of rollers for radial thinning and axial elongation of the rim and a second pair of rollers for finishing forming. The first pair of rollers includes an outer conforming roller and an inner balancing roller. The outer conforming roller has a first feature shape fillet for splitting and cutting at the rim neck position and a second feature shape fillet for extruding and thinning the blank rim and elongating it axially. The inner balancing roller is located inside the rim and at a position corresponding to the outer conforming roller. It also has an end face that abuts against the inner wall of the rim; the second pair of rollers includes an outer finishing roller and an inner top roller. The outer finishing roller has a reverse hook-shaped rounded corner for assisting in splitting and cutting at the wheel neck and assisting in thinning and finishing the rim. The inner top roller is located on the inner side of the rim and at the position corresponding to the outer finishing roller and has a third feature rounded corner for inner radial support, a straight section shape surface that is processed in conjunction with the outer finishing roller in the middle section of the rim, and a fourth feature rounded corner for completing the inner rim rounded corner forming of the inner flange at the rim opening end.

[0013] Preferably, the drive unit is used to drive the outer extrusion roller group and the inner forming roller group to perform synchronous, programmable controllable feed movements along the axial and / or radial directions, comprising: a main slide table for controlling the synchronous axial movement of the outer extrusion roller group and the inner forming roller group; and a secondary slide table for independently controlling the axial movement of the inner forming roller group. The outer extrusion roller group and the secondary slide table are fixed on the main slide table for controlling the synchronous axial movement of the outer extrusion roller group and the inner forming roller group; the inner forming roller group is fixed on the secondary slide table for controlling the independent axial movement of the inner forming roller group. A drive unit fixed to the bed is used to control the movement of the main slide table along the axial direction of the bed; a drive unit fixed to the axial direction of the main slide table is used to control the independent movement of the secondary slide table along the axial direction of the bed; a drive unit fixed to the radial direction of the main slide table is used to control the movement of the outer extrusion roller group along the radial direction; and a drive unit fixed to the secondary slide table is used to control the movement of the inner forming roller group along the radial direction.

[0014] Preferably, the roller forming unit includes an inner roller arranged along the axial direction of the billet so that its axial movement can be independently controlled. By adjusting the axial movement of the inner roller, the distance between it and the correspondingly arranged outer roller is changed, thereby achieving spinning compensation for different billet shapes.

[0015] Preferably, the inner roller is a driven support roller, which can be replaced with a thinning roller or an inner finishing roller as needed.

[0016] Preferably, each drive unit includes: a servo drive module for providing power; a position detection module for real-time detection of the position of the corresponding outer extrusion roller group and / or inner forming roller group; and a control module configured to control the servo drive module to achieve closed-loop control based on a preset forming trajectory and the feedback signal from the position detection module.

[0017] Preferably, the flexible clamping unit includes: a clamping body for connecting to the spindle drive unit to achieve rotation; a plurality of circumferentially distributed jaws for contacting and clamping the blank; and an alignment drive mechanism connected to the jaws, configured to synchronously adjust or independently control the position and clamping force of all the jaws so that the axis of the blank coincides with the rotation axis of the spindle drive unit.

[0018] Preferably, the flexible clamping unit further includes a pressure sensing module for detecting whether the billet is clamped.

[0019] Preferably, the working surface profiles of the outer extrusion roller group and / or the inner forming roller group can be adjusted in a replaceable or shape-adjustable manner.

[0020] According to another aspect of the present invention, a high-pressure extrusion molding method is provided, applicable to the above-described high-pressure extrusion molding equipment, for performing moldless extrusion-based plastic molding, comprising the following steps:

[0021] S1: Clamping and Alignment Step: The blank is clamped by the flexible clamping unit and automatic alignment is performed to make the blank axis align with the spindle axis;

[0022] S2: Trajectory planning step: Based on the shape of the target workpiece, plan the coordinated motion trajectory of the outer extrusion roller group and the inner forming roller group in the drive unit, including the axial motion trajectory and the radial motion trajectory;

[0023] S3: Rotation drive step: Start the main shaft drive unit to drive the blank to rotate;

[0024] S4: Synchronous extrusion step: During the rotation of the billet, the corresponding drive unit drives the outer extrusion roller group and the inner forming roller group to move synchronously along the planned cooperative motion trajectory, and performs continuous and symmetrical radial extrusion and axial elongation operations on the billet until the forming is completed.

[0025] The beneficial effects of this invention are as follows:

[0026] 1. Completely eliminate molds: By replacing physical molds with "CNC trajectory control + symmetrical extrusion of inner and outer rollers", the production and storage of molds are reduced, greatly reducing production costs, reducing mold changes, improving production efficiency, and achieving extremely high production flexibility of "one machine, hundreds of parts".

[0027] 2. Solved the core bottleneck of moldless forming: The innovative flexible clamping unit integrates automatic alignment, pressure sensing and feedback control functions, which fundamentally ensures the coaxiality of the blank and the spindle, and significantly improves the stability and yield of the moldless forming process.

[0028] 3. High forming quality and precision: Symmetrical extrusion improves the material stress state and reduces uneven deformation; the closed-loop CNC system ensures accurate trajectory; automatic alignment eliminates initial errors. These three factors together guarantee the high dimensional accuracy and excellent mechanical properties of the workpiece.

[0029] 4. Intelligent and error-proof: The introduction of the pressure sensing module enables quantitative control and process monitoring of clamping force, which can effectively prevent process failures such as insufficient clamping, damage to the billet due to excessive clamping force, or slippage caused by insufficient clamping force, thereby improving the automation and reliability of the equipment.

[0030] 5. Wide range of applications: It is particularly suitable for the rapid development and production of multi-variety, small-batch, high-precision rotating parts in the fields of automotive parts, aerospace, military industry, and special containers. Attached Figure Description

[0031] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0032] Figure 1 This is a top view of the overall structure of the high-pressure extrusion plastic molding equipment according to an embodiment of the present invention.

[0033] Figure 2 This is a schematic diagram of the overall structure of the main slide and the outer roller assembly in an embodiment of the present invention.

[0034] Figure 3 This is a cross-sectional view of the outer roller in an embodiment of the present invention.

[0035] Figure 4 This is a schematic diagram of the overall structure of the auxiliary slide and inner roller assembly in an embodiment of the present invention.

[0036] Figure 5 This is a cross-sectional view of the inner roller in an embodiment of the present invention.

[0037] Figure 6 This is a schematic diagram of the overall structure of the flexible clamping unit in an embodiment of the present invention.

[0038] Figure 7This is a cross-sectional view of the gripper in an embodiment of the present invention. Detailed Implementation

[0039] Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The exemplary embodiments described below and illustrated in the drawings are intended to teach the principles of the invention, enabling those skilled in the art to implement and use the invention in various environments and for various applications. Therefore, the scope of protection of the present invention is defined by the appended claims, and the exemplary embodiments are not intended, and should not be considered, a limiting description of the scope of protection of the present invention. Furthermore, for ease of description, the dimensions of the various parts shown in the drawings are not necessarily drawn to actual scale, and the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions, such as drive unit 4. Regarding orientational descriptions, such as axial (or longitudinal) directions corresponding to the bed spindle or blank axis, radial (or transverse) directions perpendicular to the bed axis, and directions or positional relationships indicated by up, down, left, right, top, bottom, etc., are all based on the orientations or positional relationships shown in the drawings and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Unless otherwise specifically stated, the order and numerical values ​​of the components and assembly steps set forth in the embodiments do not limit the scope of the present invention. Furthermore, any numerical range stated herein is intended to include all subranges contained herein, and a numerical range expressed as "value A to value B" refers to the range including endpoint values ​​A and B. Those skilled in the art will understand that terms such as "nth" and "Sn" in this invention are used only to distinguish different steps, devices, or modules, and do not represent any specific technical meaning, nor do they indicate a necessary logical order between them. For example, steps one and two can be interchanged or performed in parallel.

[0040] Traditional spinning processes rely on specific molds to determine the workpiece shape, resulting in high mold costs, poor production flexibility, and long mold changeover times, making them unsuitable for multi-variety, small-batch production needs. To overcome these drawbacks of core-mold spinning, this invention provides a high-power extrusion plastic forming device. The key to this device is the elimination of traditional core molds, employing symmetrical inner and outer roller extrusion forming technology. Specifically, while the main shaft drives the billet to rotate, a programmable control system precisely coordinates and drives one or more external conforming rollers and internal balancing rollers to synchronously feed along the workpiece's axial and radial directions. Symmetrical and continuous radial extrusion forces are applied to the billet by the inner and outer rollers, causing the metal billet to undergo gradual plastic deformation and precisely form a rotating body of the desired shape under moldless constraints, based on the roller trajectory and pressure. This invention, through moldless extrusion forming, completely eliminates the need for manufacturing, storing, and replacing dedicated molds, significantly reducing equipment costs and production preparation time, and achieving extremely high production flexibility. Simultaneously, the symmetrical extrusion method improves the material's stress state, which is beneficial for improving forming accuracy and workpiece mechanical properties, especially for the efficient and flexible manufacturing of high-precision, variable-section rotating parts.

[0041] Example 1:

[0042] <Overall Composition>

[0043] like Figures 1 to 7 As shown, the present invention provides a high-power extrusion plastic molding equipment with automatic alignment function, mainly including: bed 16, main spindle drive unit 1, flexible clamping unit 5, outer extrusion roller group 2 including at least one outer roller, inner forming roller group 3 including at least one inner roller, and drive unit 4.

[0044] The spindle drive unit 1 is fixed to one end of the bed 16 via the spindle box and is used to provide rotational power to drive the billet to rotate. Its input end is driven by the spindle drive motor 19 to rotate the gear, and the gear is fixed to the spindle 17, which is the output end.

[0045] The flexible clamping unit 5 is directly mounted on the front end of the spindle 17 via a flange, and can be used to clamp blanks of different sizes. This unit has an automatic alignment function, which can ensure that the axis of the blank coincides with the rotation axis of the spindle 17. Figure 6 As shown, the flexible clamping unit 5 includes a disc-shaped clamping body 12 with six (adjustable) radial grooves evenly distributed around its circumference. Each groove houses a gripper 13 that can slide radially. Figure 7The illustrated cross-sectional view of one of the grippers shows that the gripper head shape and blank clamping position can be designed to conform to the shape. Each gripper 13 is connected to an independent alignment drive mechanism 14. In some embodiments, the alignment drive mechanism 14 employs a high-precision servo electric cylinder. A pressure sensing module 15 (such as a piezoelectric or strain gauge pressure sensor) is embedded in the clamping surface of each gripper 13. The signals from all the servo electric cylinders and pressure sensing modules 15 are integrated and connected to the central control system of the equipment, for example, it can be integrated into the drive unit 4. Thus, whether the blank is clamped can be detected, and safety error prevention verification can be performed.

[0046] A main slide 10 is provided on the guide rail I18 at the other end of the bed 16, which can move closer to or further away from the flexible clamping unit 5 along the axial direction of the bed 16.

[0047] Combination Figure 2 As shown, an outer rotary wheel seat 20 is provided on the guide rail II 28 of the main slide table 10. The outer extrusion roller group 2 is mounted on the outer rotary wheel seat 20 and moves synchronously with the main slide table 10 along the axial direction of the bed 16 on the guide rail I 18. One end of the outer rotary wheel seat 20 is fixed to the drive unit 4 corresponding to the outer extrusion roller group 2. The drive unit 4 enables the outer extrusion roller group 2 to move radially along the bed 16 on the guide rail II 28.

[0048] The outer extrusion roller group 2 serves as the outer roller group used for extruding the outer side of the billet, such as... Figure 1 As shown, the outer conforming roller 6 or the outer finishing roller 8 can be selected according to process or functional requirements. Figure 2 These two outer rollers are uniformly labeled as outer extrusion roller group 2.

[0049] The inner forming roller assembly 3 is mounted on the inner rotating wheel seat 21 for supporting and forming the inner side of the billet. The inner rotating wheel seat 21 is fixed to the guide rail III 38 of the auxiliary slide table 11 by a slider. The auxiliary slide table 11 is fixed to the guide rail IV 48 of the main slide table 10 by a corresponding slider. This allows the auxiliary slide table 11 and the main slide table 10 to move synchronously along the axial direction of the bed 16, and the inner forming roller assembly 3 to move independently along the axial direction on the guide rail IV 48. Simultaneously, one end of the drive unit 4 of the inner forming roller assembly 3 is fixed to the inner rotating wheel seat 21, enabling the inner forming roller assembly 3 to move radially along the bed 16 via the guide rail III 38 using the drive unit 4. Figure 4 As indicated by the middle arrow.

[0050] The inner forming roller group 3 uses a driven carbide support roller, whose function is to provide internal support and form a symmetrical extrusion with the outer extrusion roller group 2. For example Figure 1 As shown, the inner forming roller group 3 can be selected from the inner balancing roller 7 and the inner top roller 9, which are used for forming, as inner rollers.

[0051] Here, the working surface profiles of the outer extrusion roller group 2 and / or the inner forming roller group 3 are replaceable or shape-adjustable to further expand the processing range of the equipment.

[0052] The drive unit 4 is the "brain" of the equipment. For example, it is equipped with different hydraulic cylinders or motors in the form of a CNC drive unit to drive and control the movement of different components. This allows it to drive the outer extrusion roller group 2 and the inner forming roller group 3 to perform synchronous, programmable feed movements along the axial and / or radial direction of the blank. It includes a multi-axis motion control card, a servo driver, a servo motor (for driving the outer extrusion roller group 2 and the inner forming roller group 3 to move along the bed axially and radially), and a position feedback element (such as a grating ruler). All motion axes (outer roller X / Z axis, inner roller X / Z axis, spindle rotation axis, and even the gripper drive axis) are integrated into a unified CNC system.

[0053] Preferably, the drive unit 4 is a closed-loop servo control system capable of driving: a main slide 10 that controls the synchronous axial movement of the outer extrusion roller group 2 and the inner forming roller group 3, and a secondary slide 11 that independently controls the axial movement of the inner forming roller group 3. The outer extrusion roller group 2 and the secondary slide 11 are fixed on the main slide 10 to control the synchronous axial movement of the outer extrusion roller group 2 and the inner forming roller group 3; the inner forming roller group 3 is fixed on the secondary slide 11 to control its independent axial movement, which can be used to adjust the compensation between the inner and outer rollers. This can be used when adjusting the spinning program; once the program is fixed, the compensation is fixed, and the inner roller group no longer performs independent axial movement. Therefore, the drive unit 4 includes: a servo drive module for providing power; a position detection module for real-time detection of the position of the outer extrusion roller group 2 and / or the inner forming roller group 3; and a control module configured to control the servo drive module according to a preset forming trajectory and feedback signals from the position detection module to achieve precise closed-loop control of the inner and outer roller movement trajectories. Thus, the drive unit 4 fixed to the bed 16 can control the main slide 10 to move along the axial direction of the bed 16, the drive unit 4 fixed to the axial direction of the main slide 10 can control the auxiliary slide 11 to move independently along the axial direction of the bed 16, the drive unit 4 fixed to the radial direction of the main slide 10 can control the outer extrusion roller group 2 to move in the radial direction, and the drive unit 4 fixed to the auxiliary slide 11 can control the inner forming roller group 3 to move in the radial direction.

[0054] <Equipment Workflow>

[0055] Step 1 (S1): Intelligent clamping and alignment.

[0056] The operator places the workpiece blank in the center area of ​​each of the open grippers 13. The "automatic clamping" program is started on the control panel. The program first commands the servo electric cylinders of all grippers 13 to move synchronously and slowly towards the center. When the pressure sensor module 15 on a certain gripper 13 detects that the pressure value first exceeds a low "contact threshold" (e.g., 50N), this signal is fed back to the control system, and the gripper immediately stops moving forward and maintains its current position. After all grippers 13 report contact with the blank, the system enters the "precise alignment" stage: the system reads the real-time values ​​of all pressure sensor modules 15, calculates using an algorithm, and slightly adjusts the grippers 13 with less force to continue micro-feeding until the pressure values ​​fed back by all sensors are within a very small error range (e.g., a preset ±10N). At this point, it is considered that the workpiece blank has been precisely aligned on the spindle axis. Finally, the system instructs all grippers 13 to synchronously increase the clamping force to the required "locking force" (e.g., 5000N) and maintain it, completing the clamping process. This process is fully automated, requiring no human intervention, and the pressure data is recorded for quality traceability.

[0057] In this way, the billet can be placed between multiple grippers 13 of the flexible clamping unit 5, and the automatic alignment program is started. The alignment drive mechanism 14 drives the grippers 13 to retract synchronously towards the center until the pressure sensor module signals on all grippers 13 reach the preset contact threshold. The system determines that the billet has been initially aligned and in contact. Subsequently, the system fine-tunes the position of the corresponding gripper 13 according to the feedback of each pressure sensor module 15, so that each pressure sensor module 15 is subjected to uniform force, completes high-precision automatic alignment, and finally increases the clamping force to the set value and locks it.

[0058] Step 2 (S2): Trajectory planning.

[0059] Based on the CAD model of the target workpiece, technicians use relevant software to generate the spatial coordinated motion trajectory (G-code) of the cutting tip of the outer extrusion roller group 2 and the support point of the inner forming roller group 3. This trajectory defines the radial and axial positions of the inner and outer roller groups at each point during the extrusion process. The trajectory program is transmitted to the CNC system via USB flash drive or network.

[0060] Thus, based on the three-dimensional digital model of the target workpiece, the coordinated motion trajectory program of the outer extrusion roller group 2 and the inner forming roller group 3 can be planned and generated in the drive unit 4.

[0061] Step 3 (S3): Rotation drive step.

[0062] Start the spindle drive unit 1 to drive the precisely clamped workpiece blank to rotate at a constant speed (e.g., 2000 rpm).

[0063] Step 4 (S4): Rotation and synchronous extrusion molding.

[0064] Subsequently, the CNC program is initiated, and drive unit 4 strictly follows the input trajectory program to control the servo motors driving the outer extrusion roller group 2 and the inner forming roller group 3. For example, at the start of forming, the outer extrusion roller group 2 quickly moves to the starting point at the edge of the workpiece blank, while the inner forming roller group 3 moves synchronously to the corresponding inner support point. Then, the corresponding rollers (also called inner and outer rollers or roller group forming units) of the outer extrusion roller group 2 and the inner forming roller group 3 begin to slowly and synchronously feed along the axial direction (Z-axis), while continuously and smoothly adjusting their radial (X-axis) positions according to the trajectory requirements, applying a constant and symmetrical radial force to the rotating workpiece blank. Under the action of strong triaxial compressive stress, the metal blank undergoes plastic flow, the wall thickness gradually decreases, the length direction extends, and finally conforms to the shape defined by the forming trajectory. The entire process is continuous and gradual.

[0065] In this way, the inner and outer rollers can apply continuous and symmetrical radial extrusion force to the rotating billet starting from one end, causing the metal material to undergo plastic flow, the billet wall thickness to decrease and extend along the axial direction, and finally form the desired shape.

[0066] Step 5 (S5): Unloading.

[0067] Once the program finishes running, the inner and outer rollers quickly return to their safe positions, and the main shaft stops rotating. The robotic arm extends into the working area to grip the formed workpiece. Upon receiving the release command, the flexible clamping unit 5 simultaneously retracts each gripper 13, allowing the operator or robotic arm to remove the high-precision formed workpiece.

[0068] Example 2:

[0069] Building upon Example 1, to further enhance the equipment's ability to process complex parts, the outer extrusion roller group 2 and the inner forming roller group 3 are arranged along the X-axis in two or three pairs of extrusion pairs consisting of corresponding outer extrusion rollers and inner forming rollers, i.e., roller group forming units in the form of paired roller groups. For example, the first pair of roller groups is responsible for forming the front section of the workpiece, and the second roller group is responsible for forming the rear section. The trajectories of each roller group forming unit can be different and can be controlled independently, thereby efficiently forming complex variable cross-section parts with multiple different cone angles or curvatures in a single clamping operation.

[0070] Thus, the roll forming unit includes an inner roll arranged along the axial direction of the billet so that its axial movement can be independently controlled. The axial movement of the inner roll, which is located inside the billet, is adjusted by a drive unit connected to the roll forming unit, and the spacing between the inner roll and the outer roll, which is arranged on the outside of the billet, is changed to achieve spinning compensation for different billet shapes.

[0071] Example 3:

[0072] Based on Embodiment 1, the outer extrusion roller group 2 has a modular design with quick-change roller heads, equipped with a series of roller heads with different radii of curvature or special profiles. A similar design can also be adopted for the inner forming roller group 3, or a "multi-segment" profile adjustable roller composed of multiple small rollers can be used to further adapt to a wider range of workpiece shape requirements.

[0073] Example 4:

[0074] Based on Example 1, two outer roller groups are provided: the outer conforming roller 6 and the inner balancing roller 7 constitute the first pair of rollers for radial thinning and axial elongation of the rim, and the outer finishing roller 8 and the inner top roller 9 constitute the second pair of rollers for corresponding finishing forming. The first and second roller groups are mainly used to complete the outer rim forming. The outer conforming roller 6 and the inner balancing roller 7 of the first pair of rollers are used to realize the first pass (thinning pass) of the processing, and are arranged inside and outside one side of the blank workpiece; the outer finishing roller 8 and the inner top roller 9 of the second pair of rollers are used to realize the second pass (finishing forming pass) of the processing, and are arranged inside and outside the other side of the blank workpiece. The first and second roller groups are horizontally opposite each other at 180°, but are not limited to this, as long as they are arranged separately on the circumferential side of the workpiece.

[0075] More specifically, the roll forming unit, consisting of an outer extrusion roll group 2 and an inner forming roll group 3, includes: a first pair of roll groups for radial thinning and axial elongation of the rim and a second pair of roll groups for finishing forming. The first pair of roll groups includes an outer conforming roll 6 and an inner balancing roll 7. The outer conforming roll 6 has a first feature shaping fillet for splitting and cutting at the rim neck position (see...). Figure 3 The first pair of rollers consists of an outer finishing roller 8 and an inner top roller 9. The outer finishing roller 8 has a reverse hook-shaped rounded corner for assisting in splitting and cutting at the wheel neck and assisting in thinning and finishing the wheel rim. The inner top roller 9 is located on the inner side of the wheel rim and corresponds to the outer finishing roller 8. It has a third characteristic rounded corner for inner radial support, a straight section shaping surface that is processed in conjunction with the outer finishing roller 8 in the middle section of the wheel rim, and a fourth characteristic rounded corner for completing the inner rounded corner forming of the inner rim opening end.

[0076] In addition, according to the requirements for the fineness of the metallographic structure of the rim, the inner balance roller 7 can be replaced with the inner thinning roller, which, together with the outer conforming roller 6, simultaneously thins and extrudes the blank workpiece on the inner and outer sides of the rim; similarly, according to the requirements for the surface strengthening of the rim, the inner top roller 9 can be replaced with the inner finishing roller, which can compress the rim surface according to the preset trajectory line after forming to improve its hardness.

[0077] In summary, this invention creatively provides an advanced plastic forming solution with high flexibility, high precision, and high reliability by integrating two core technologies: "flexible automatic alignment and clamping" and "CNC dieless symmetrical extrusion." Its core concept lies in eliminating expensive solid mandrels and instead using a CNC system to precisely control the movement trajectory of the spinning wheel, directly "drawing" the final shape of the workpiece. The advantages of this revolution are: firstly, it completely eliminates the cost of dedicated molds for each product, greatly reducing production preparation costs and time; secondly, it endows the production line with extremely high flexibility, allowing for the processing of parts of different shapes simply by changing the CNC program, truly achieving rapid response and mixed-line processing for multi-variety, small-batch, and even single-piece production. Thus, it effectively solves the pain points of traditional die-spinning processes and has significant industrial application value.

[0078] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-power extrusion plastic molding equipment, characterized in that, The device is used for flexible moldless plastic forming of wheel blanks, comprising: a bed (16); a spindle drive unit (1) for driving the blank to rotate with the spindle (17); an outer extrusion roller group (2) including at least one outer roller for extruding the outer side of the blank; an inner forming roller group (3) including at least one inner roller for supporting the inner side of the blank; a drive unit for correspondingly driving the outer extrusion roller group (2) and the inner forming roller group (3) to feed along the axial and / or radial direction of the blank; and a flexible clamping unit (5) disposed on the spindle drive unit (1) for clamping blanks of different sizes, wherein the correspondingly arranged outer roller and inner roller constitute a roller forming unit. The drive unit is used to drive the outer extrusion roller group (2) and the inner forming roller group (3) to perform synchronous, programmable controllable feed movements along the axial and / or radial directions. It includes: a main slide (10) that controls the synchronous axial movement of the outer extrusion roller group (2) and the inner forming roller group (3); and a secondary slide (11) that independently controls the axial movement of the inner forming roller group (3). The outer extrusion roller group (2) and the secondary slide (11) are fixed on the main slide (10) for controlling the synchronous axial movement of the outer extrusion roller group (2) and the inner forming roller group (3). The inner forming roller group... (3) Fixed on the auxiliary slide (11) for controlling the independent axial movement of the inner forming roller group (3); the drive unit fixed on the bed (16) for controlling the main slide (10) to move along the axial direction of the bed (16), the drive unit fixed on the axial direction of the main slide (10) for controlling the auxiliary slide (11) to move independently along the axial direction of the bed (16), the drive unit fixed on the radial direction of the main slide (10) for controlling the outer extrusion roller group (2) to move in the radial direction, and the drive unit fixed on the auxiliary slide (11) for controlling the inner forming roller group (3) to move in the radial direction. The roller forming unit includes an inner roller arranged along the axial direction of the billet, the axial movement of which can be independently controlled. By adjusting the axial movement of the inner roller, the distance between it and the correspondingly arranged outer roller is changed, thereby achieving spinning compensation for different billet shapes. The main slide (10) is mounted on the guide rail I (18) of the bed (16). An outer rotary wheel seat (20) is mounted on the guide rail II (28) of the main slide (10). The outer extrusion roller group (2) is mounted on the outer rotary wheel seat (20) and moves synchronously with the main slide (10) along the axial direction of the bed (16) on the guide rail I (18). One end of the outer rotary wheel seat (20) is fixed on the drive unit (4) corresponding to the outer extrusion roller group (2). The drive unit (4) enables the outer extrusion roller group (2) to move radially along the bed (16) on the guide rail II (28). The inner forming roller assembly (3) is mounted on the inner rotating wheel seat (21). The inner rotating wheel seat (21) is fixed to the guide rail III (38) of the auxiliary slide (11) by a slider. The auxiliary slide (11) is fixed to the guide rail IV (48) of the main slide (10) by a corresponding slider, so as to realize the synchronous axial movement of the auxiliary slide (11) and the main slide (10) along the bed (16) and the independent axial movement of the inner forming roller assembly (3) on the guide rail IV (48). One end of the drive unit (4) of the inner forming roller assembly (3) is fixed to the inner rotating wheel seat (21), so as to realize the movement of the inner forming roller assembly (3) along the bed (16) radially via the guide rail III (38) by the drive unit (4). The roller forming unit, consisting of an outer extrusion roller group (2) and an inner forming roller group (3), includes a first pair of rollers arranged spaced apart from each other on the circumferential side of the workpiece for radial thinning and axial elongation of the rim, and a second pair of rollers for finishing forming. The first and second pairs of rollers are positioned horizontally opposite each other at 180°.

2. The high-power extrusion plastic molding equipment according to claim 1, characterized in that, The first pair of rollers includes an outer conforming roller (6) and an inner balancing roller (7). The outer conforming roller (6) has a first feature shape rounded corner for splitting and cutting at the wheel neck position, and a second feature shape rounded corner for extruding and thinning the blank wheel rim and stretching the blank wheel rim axially. The inner balancing roller (7) is located on the inner side of the wheel rim and is positioned corresponding to the outer conforming roller (6) and has an end face that abuts against the inner wall of the wheel rim. The second pair of rollers includes an outer finishing roller (8) and an inner top roller (9). The outer finishing roller (8) has a reverse hook-shaped rounded corner for assisting splitting and cutting at the wheel neck and assisting in thinning and finishing the wheel rim. The inner top roller (9) is located on the inner side of the wheel rim and is positioned corresponding to the outer finishing roller (8) and has a third feature shape rounded corner for inner radial support, a straight section shape surface that is processed in conjunction with the outer finishing roller (8) in the middle section of the wheel rim, and a fourth feature shape rounded corner for completing the inner rim rounded corner forming of the inner flange at the opening end of the wheel rim.

3. The high-power extrusion plastic molding equipment according to claim 1, characterized in that, The inner roller is a driven support roller, which can be replaced with a thinning roller or an inner finishing roller as needed.

4. The high-power extrusion plastic molding equipment according to claim 1, characterized in that, Each drive unit includes: a servo drive module for providing power; a position detection module for real-time detection of the position of the corresponding outer extrusion roller group (2) and / or inner forming roller group (3); and a control module configured to control the servo drive module to achieve closed-loop control based on the preset forming trajectory and the feedback signal from the position detection module.

5. The high-power extrusion plastic molding equipment according to claim 1, characterized in that, The flexible clamping unit (5) further includes: a clamping body (12) for connecting with the spindle drive unit (1) to achieve rotation; a plurality of circumferentially distributed grippers (13) for contacting and clamping the blank; and a alignment drive mechanism (14) connected to the grippers (13) and configured to synchronously adjust or independently control the position and clamping force of all the grippers (13) so that the axis of the blank coincides with the rotation axis of the spindle drive unit (1).

6. The high-power extrusion plastic molding equipment according to claim 5, characterized in that, On the clamping surface of each gripper (13), a pressure sensing module (15) for detecting whether the workpiece is clamped is embedded. The feedback from each pressure sensing module (15) is used to adjust the position of the corresponding gripper (13) so that each pressure sensing module (15) is subjected to uniform force, thereby realizing quantitative control of clamping force. When the real-time values ​​of all pressure sensing modules (15) are read, the gripper (13) with smaller force is adjusted to continue micro-feeding until the pressure values ​​fed back by all pressure sensing modules (15) are within an error range. It is then considered that the workpiece workpiece has been accurately aligned on the spindle axis.

7. The high-strength extrusion molding equipment according to any one of claims 1 to 6, characterized in that, The working surface profiles of the outer extrusion roller group (2) and / or the inner forming roller group (3) can be adjusted in a replaceable or shape-adjustable manner.

8. A high-pressure extrusion plastic molding method, characterized in that, The high-power extrusion plastic molding equipment applicable to any one of claims 1 to 7, for performing dieless extrusion-based plastic molding, includes the following steps: S1: Clamping and alignment step: Clamp the blank through the flexible clamping unit (5) and perform automatic alignment to make the blank axis align with the spindle axis; S2: Trajectory planning steps: Based on the shape of the target workpiece, plan the coordinated motion trajectory of the outer extrusion roller group (2) and the inner forming roller group (3) in the drive unit, including the axial motion trajectory and the radial motion trajectory; S3: Rotation drive step: Start the main shaft drive unit (1) to drive the blank to rotate; S4: Synchronous extrusion step: During the rotation of the billet, the corresponding drive unit drives the outer extrusion roller group (2) and the inner forming roller group (3) to move synchronously along the planned cooperative motion trajectory, and performs continuous and symmetrical radial extrusion and axial elongation operations on the billet until the forming is completed.

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