A profile extrusion device and method

Abstract

The application discloses a special-shaped extrusion device and an extrusion method, and belongs to the technical field of polymer material and composite material extrusion molding. The device comprises a die holder, a die, a supporting column and a hydraulic lifting device. The inner cavity of the die is formed by a generatrix curve comprising at least one circular arc section. The supporting column supports a material rod. The hydraulic lifting device drives the material rod to enter the inner cavity of the die for extrusion. The inner cavity of the die has seven configurations. The stress of the material is controlled by the difference in the curvature of the generatrix, so that the axial orientation degree, the uniformity of the cross-sectional density and the precise control of the residual stress distribution of the product are realized. The double-stage self-adaptive hydraulic control is adopted for the die with the composite type of the upper convex arc and the lower concave arc. The method comprises parameter recommendation and self-learning update of a three-dimensional process knowledge graph. The application realizes active regulation of the micro performance of the product and reduces the debugging cost of multi-configuration switching.

Description

Technical Field

[0001] This invention relates to the field of polymer and composite material extrusion molding technology, specifically to a profile extrusion device and extrusion method. Background Technology

[0002] Extrusion molding is a widely used forming method in the field of materials processing. By applying a pushing force to the preform, the material is forced through a die with a specific internal cavity cross-section to obtain a product with the target cross-sectional shape and properties. This method is widely used in the molding and processing of polymer materials, composite materials, engineering plastics, as well as ceramic preforms and metal powder preforms.

[0003] Existing extrusion equipment typically uses a conical die with a straight inner cavity generatrix, where the cross-section shrinks uniformly and linearly from the inlet to the outlet, resulting in a simple structure and stable process. However, this single-configuration, straight-shrinking die creates a relatively uniform flow field distribution when the material flows through the inner cavity, making it impossible to directionally control the flow for different product microstructure requirements.

[0004] Studies have shown that the curvature direction and amplitude of the generatrix within the die cavity have a decisive influence on the microstructure of the product: when the generatrix bulges outward, the material is subjected to radial expansion stress in the middle section of the cavity, the axial orientation decreases, and the product has better isotropy; when the generatrix is ​​concave inward, the material is subjected to axial compression and radial constraint throughout the entire process, the axial orientation increases, and the axial mechanical properties of the product are strengthened; and for a composite configuration with a spherical cavity near the exit end and an inward concave arc cavity far from the exit end, the material is subjected to omnidirectional isobaric homogenization treatment in the spherical cavity, which can obtain a product with optimal cross-sectional density uniformity.

[0005] Currently, although some research involves the design of irregularly shaped dies, the following main shortcomings exist: First, the internal cavity configuration of the die is limited to a single type, usually only a linear contraction type, lacking a systematic multi-configuration scheme, especially a composite configuration design that combines generatrices with different curvature directions; Second, after changing the die configuration, the coupling relationship between pressure, velocity, and temperature becomes complex, and the adjustment of process parameters mainly relies on manual experience, resulting in a long adjustment cycle and a high scrap rate; Third, for composite dies with segmented different flow characteristics, such as the upper spherical cavity and the lower concave arc continuous composite type, there is a lack of specific staged control strategies. When the spherical cavity is not filled sufficiently, the cross-sectional density of the product is uneven, and if the control mode is not switched in time after filling, overpressure and material breakage are likely to occur.

[0006] Therefore, there is an urgent need for an extrusion device and method that can systematically provide a variety of irregular internal cavity configurations and be equipped with intelligent process control methods, so as to achieve active control of the microscopic properties of the product and reduce the process debugging cost when switching between multiple configurations. Summary of the Invention

[0007] Technical Objective: To address the problems of existing extrusion devices with single die cavity configurations, which prevent active control of product microstructure through configuration selection; low efficiency in process parameter adjustment and high scrap rate during multi-configuration switching; and the lack of targeted phased control strategies for composite dies with an upper convex arc and a lower concave arc, this invention discloses a non-circular extrusion device and extrusion method.

[0008] Technical solution: To achieve the above technical objectives, the present invention adopts the following technical solution: A profile extrusion apparatus, comprising the following accessories: Die holder: Used to fix the die and withstand the reaction force during the extrusion process.

[0009] Die: Mounted on the die base, it has an inner cavity extending along the extrusion direction. The inner cavity is formed by a generatrix curve containing at least one arc segment. By selecting different curvature directions (convex or concave) and different curvature amplitudes of the arc segments, seven different inner cavity configurations can be constructed, thereby enabling directional control of the stress state experienced by the material during extrusion. The die is detachably mounted on the die base. The seven different inner cavity configurations use a uniform external dimension and can be interchanged on the same die base.

[0010] Support column: Used to support the extruded bar and align the axis of the bar with the central axis of the die cavity to ensure coaxiality of the feed.

[0011] Hydraulic lifting device: connected to the support column, providing driving force to push the material bar into the die cavity for extrusion, with an extrusion speed range of 0.02~100m / min and an extrusion pressure range of 0.1~35MPa.

[0012] The above-mentioned basic device may further include the following extended components: For a composite shrinkage die with an inward concave arc at the top and an outward convex arc at the bottom, the outward convex arc segment at the inlet provides gentle initial shrinkage, while the inward concave arc segment at the outlet provides enhanced final shrinkage. The two segments meet the tangential continuity condition at the transition section, achieving a gradual transition in material shrinkage rate from slow to rapid. This is suitable for highly filled composite materials and brittle materials that are sensitive to inlet stress. For a composite die with an outward convex arc at the top and a straight line at the bottom, the straight line segment at the inlet provides uniform and stable pre-compression, while the outward convex arc segment at the outlet provides expansion homogenization. The combination of the two segments combines the process stability of the straight line type with the improved cross-sectional density uniformity of the convex arc type.

[0013] Configuration identifier, information reader and control unit: The configuration identifier is set on the die and stores the configuration code; the information reader is installed on the die base, reads the configuration code and transmits it to the control unit; the control unit automatically retrieves the corresponding extrusion pressure-stroke curve according to the configuration code and performs adaptive hydraulic control, eliminating the debugging cost of manually setting parameters when switching between multiple configurations.

[0014] Dual-stage control strategy: When the die is a composite type with an upper convex arc and a lower concave arc, the control unit determines the moment when the material front enters the expansion section of the convex arc by real-time detection of the rate of change of the extrusion pressure dP / dt. At this moment, the control mode is switched from constant speed to constant pressure to ensure that the material is uniformly filled in the convex arc section and to ensure the uniformity of the cross-sectional density of the product.

[0015] Temperature control unit: thermally connected to the mold base, it maintains the working temperature of the die between -20℃ and 150℃, and provides the optimal temperature range for each configuration based on the flow characteristics of different configurations.

[0016] The present invention also provides an extrusion method for a profiled extrusion device, comprising the following steps: S1, placing a material bar on a support column and aligning it with the central axis of the die; S2, obtaining the die configuration code; S3, determining the pushing process parameters according to the configuration code; S4, driving the material bar into the die cavity to extrude the product according to the determined process parameters; in addition, the method also includes a parameter recommendation and self-learning update step based on a three-dimensional process knowledge graph of configuration-material-performance.

[0017] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement an extrusion method for a profile extrusion device as described above.

[0018] Beneficial effects: The irregular extrusion device and extrusion method provided by the present invention have the following beneficial effects: (1) Multi-configuration active control of product microstructure: Seven systematic irregular cavity configurations allow operators to actively control the axial orientation, cross-sectional density uniformity, and residual stress distribution of the product by selecting the die configuration. The convex arc type is suitable for applications requiring isotropy; the concave arc type is suitable for applications requiring high axial strength; the upper convex arc and lower concave arc composite type can achieve both high axial orientation and excellent cross-sectional density uniformity by relaxing and homogenizing the radial stress of the convex arc segment; the upper concave arc and lower straight line composite shrinkage type achieves both axial orientation and dimensional accuracy by combining straight pre-compression and concave arc enhanced shrinkage; the upper concave arc and lower convex arc composite shrinkage type is suitable for extrusion of highly filled composite materials and brittle materials that are sensitive to inlet stress by gradually combining inlet end gentle shrinkage and outlet end enhanced shrinkage.

[0019] (2) The circular arc of the busbar eliminates the sudden change in the flow field. Compared with the straight die, the present invention adopts a busbar curve containing at least one circular arc segment. The curves satisfy the tangent continuity constraint at the connection point, which eliminates the sudden change in the flow field at the corner of the traditional segmented splicing busbar, effectively suppresses the secondary flow at the transition section of the composite die, and improves the cross-sectional quality of the product.

[0020] (3) Configuration coding driven adaptive control significantly reduces debugging costs. The combination of configuration identifier and information reader realizes automatic identification of the die configuration. The control unit automatically initializes the process parameters accordingly, eliminating scrap caused by manual parameter setting errors during multi-configuration switching, and reducing the debugging time of the changeover process from several hours to several minutes.

[0021] (4) Dual-stage control ensures the extrusion stability of the composite die. The dedicated dual-stage control strategy monitors the rate of change of the extrusion pressure dP / dt in real time. When dP / dt drops below the preset switching threshold, the control mode is automatically switched from constant speed to constant pressure. This effectively avoids uneven product cross-sectional density and overpressure material breakage caused by the failure to switch the control mode in time during the expansion section of the convex arc. This greatly improves the extrusion stability of the composite die with the upper convex arc and the lower concave arc.

[0022] (5) The process knowledge graph continuously optimizes the process window through self-learning. The three-dimensional process knowledge graph updates the process parameters batch by batch by feeding back the measured data of each extrusion, thereby continuously improving the accuracy of process parameter recommendations and effectively reducing the scrap rate. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0024] Figure 1 This is a schematic diagram of the overall structure of the irregular extrusion device of the present invention.

[0025] Figure 2 The diagram shows seven cross-sectional configurations of the inner cavity of the mold of the present invention, wherein (a) is a straight-line contraction type, (b) is an outward convex arc contraction type, (c) is an inward concave arc contraction type, (d) is a composite contraction type with an upper inward concave arc and a lower straight line, (e) is a composite type with an upper outward convex arc and a lower inward concave arc, (f) is a composite contraction type with an upper inward concave arc and a lower outward convex arc, and (g) is a composite type with an upper outward convex arc and a lower straight line. Figure 2 The arrows in the diagrams indicate the extrusion direction (exit end at the top, inlet end at the bottom).

[0026] Figure 3 This is a flowchart of the two-stage hydraulic control logic for a composite die with an upper convex arc and a lower concave arc.

[0027] Figure 4 This is a schematic diagram of the structure of a three-dimensional process knowledge graph consisting of configuration, materials, and performance.

[0028] Figure 5 This is a schematic diagram of the cross-section of the inner cavity of a composite shrinkage die with an upper concave arc and a lower convex arc.

[0029] Figure 6 This is a schematic diagram comparing the pressure-stroke curves of the extrusion mechanism.

[0030] In the diagram: 1 is the mold base, 2 is the die, 3 is the support column, 4 is the hydraulic lifting device, 5 is the material bar, 6 is the information reader, 7 is the control unit, 8 is the temperature control unit, 9 is the servo hydraulic valve group, 10 is the sensor array, 11 is the inlet end, 12 is the outlet end, 13 is the generatrix curve, 14 is the inner cavity, 15 is the outer wall of the die, and 16 is the convex arc cavity. Figure 2 (e) and (g)), 17 is an inward concave arc cavity ( Figure 2 (c) to (f)), 18 is the transition section ( Figure 2 In (d), (e) and (g), 23 is the lower convex arc generatrix, 24 is the upper concave arc generatrix, and 25 is the transition section of the composite contraction type of upper concave arc and lower convex arc. Detailed Implementation

[0031] The present invention will now be described more clearly and completely by way of a preferred embodiment in conjunction with the accompanying drawings, but this does not limit the invention to the scope of the described embodiment.

[0032] See Figure 1 The irregular extrusion device of the present invention consists of three parts: a physical layer, a sensing and execution layer, and an intelligent control layer. Each part works together to achieve precise control of the entire irregular extrusion process.

[0033] The physical layer includes a mold base 1, a die 2, a support column 3, a hydraulic lifting device 4, and a material bar 5. The mold base 1 is a metal part with sufficient rigidity, and it has a quick-change interface for fixing the die 2. The quick-change interface is equipped with a locking mechanism to ensure that the die 2 does not shift or rotate under the highest pushing pressure. The die 2 is detachably installed on the quick-change interface of the mold base 1. The seven different internal cavity configurations of the die 2 adopt a unified external fit dimension (unified outer diameter, unified sealing groove position, unified fastening fit surface), and can be interchanged and installed on the same mold base 1 without recalibrating the centering accuracy, reducing the mechanical operation cost of switching between multiple configurations.

[0034] like Figure 1 As shown, the support column 3 supports the material bar 5, and its top positioning surface is coaxial with the inlet end 11 of the die 2, ensuring that the material bar 5 is advanced along the central axis and avoiding uneven product wall thickness caused by eccentric feeding. The hydraulic lifting device 4 is connected to the support column 3, and by driving the support column 3 to move upward, it pushes the material bar 5 into the inner cavity 14 of the die and performs extrusion. In this invention, the direction of the material bar 5 entering the die 2 is from bottom to top ( Figure 1 As shown), with the outlet end 12 at the top and the inlet end 11 at the bottom, this design allows gravity-assisted materials to converge upwards, which is beneficial for the uniform filling of the concave arc cavity and spherical cavity.

[0035] The sensing and execution layer includes a sensor array 10, a servo hydraulic valve assembly 9, and a temperature control unit 8. The sensor array 10 contains pressure sensors, displacement sensors, and temperature sensors, which monitor the pushing pressure P, the hydraulic cylinder's pushing displacement S, and the mold base temperature T in real time, with a sampling frequency of no less than 100Hz. The servo hydraulic valve assembly 9 adjusts the hydraulic cylinder's pressure and pushing speed according to the instructions of the control unit 7. The temperature control unit 8 is thermally connected to the mold base 1, maintaining the working temperature of the die 2 within the range of -20℃ to 150℃.

[0036] The intelligent control layer is the control unit 7, which is connected to the sensor array 10, the information reader 6, the servo hydraulic valve group 9 and the temperature control unit 8 to realize adaptive closed-loop control of the entire extrusion process.

[0037] See Figure 2 The inner cavity 14 of the die 2 is formed by a generatrix curve 13, which includes at least one arc segment. In the preferred embodiment, the arc length L of the arc segment satisfies the formula... Where R is the radius of curvature (unit: mm) and X is the corresponding central angle (unit: degrees), this formula forms the basis for the standardized description of the die geometry parameters in this invention. The geometric characteristics and performance regulation mechanisms of the seven internal cavity configurations are as follows: (1) Linear contraction type (e.g.) Figure 2 As shown in (a): Generatrix curve 13 is a straight line, and the inner cavity cross section shrinks uniformly and linearly from the inlet end 11 to the outlet end 12, with the shrinkage half angle θ (the angle between the inlet end face and the generatrix) as the main parameter. This configuration has the most uniform flow field during extrusion, and the material is subjected to balanced axial compression. The axial orientation and cross-sectional density of the extruded product are at a moderate level, making it suitable as a benchmark for comparing the performance of the other six configurations. It is also the configuration with the widest process window and the highest extrusion stability.

[0038] (2) Outwardly convex arc contraction type (e.g.) Figure 2 As shown in (b): Generatrix curve 13 is an outwardly convex arc. The width of the cross-section in the middle of the inner cavity is greater than the corresponding cross-section width of the straight type under the same inlet and outlet parameters, forming a drum-shaped geometric feature. The arc parameters are described by the radius of curvature R1 and the central angle X1, and the arc length is... When the material flows through the waist zone, the cross-sectional area increases, the flow velocity decreases, and the pressure rises. It experiences radial expansion stress, and its axial orientation is lower than that of a straight-line extrusion, resulting in better isotropy in the finished product. This makes it suitable for applications requiring high uniformity of cross-sectional properties. It should be noted that the flow velocity in the waist zone is lower and the material residence time is longer; therefore, in high-temperature extrusion conditions, the lower limit of the extrusion speed should be controlled to prevent thermal decomposition of the material.

[0039] (3) Concave arc contraction type (e.g.) Figure 2As shown in (c): Generatrix curve 13 is an inwardly concave arc, forming the narrowest cross-section (concave arc cavity 17) at the center of the inner cavity. The cross-sectional area is the smallest at the waist, and the material is subjected to axial compression and radial constraint throughout the entire process, resulting in the highest axial shear stress and the highest axial orientation. The product has the best axial tensile and compressive strength. The arc parameters are described by R2 and X2, and the arc length is... This configuration is suitable for products with strict requirements on axial mechanical properties. At higher extrusion speeds, significant shear heat buildup occurs at the waist; therefore, the maximum extrusion speed should be set based on the material's thermal stability.

[0040] (4) Upper concave arc and lower straight line composite contraction type (such as...) Figure 2 As shown in (d): the upper generatrix curve near the outlet end 12 is a concave arc (parameters R3, X3), while the lower generatrix curve away from the outlet end 11 is a straight line; the two sections satisfy the tangent continuity condition at the transition section 18—that is, the slopes of the two curves are equal at the connection point, ensuring a smooth transition of the flow channel without any bends. The material first enters the straight section to establish a stable pre-compression state, and then enters the concave arc section to accelerate contraction. The axial orientation at the secondary flow channel is between that of the straight line and the pure concave arc, combining the dimensional accuracy control capability of the straight section with the axial orientation enhancement effect of the concave arc section.

[0041] (5) Composite type with an upper convex arc and a lower concave arc (such as...) Figure 2 As shown in (e): the upper section of the generatrix near the outlet end 12 is a convex arc (parameters R6, X6), and the lower section of the generatrix away from the outlet end is a concave arc (parameters R7, X7). The two sections are tangentially connected at the transition section (satisfying C). 1 Continuous, C 1 (This is a mathematical representation of the order of curve continuity). The upper convex arc cavity 16 forms a drum-shaped region in the middle section with a cross-sectional area larger than that of the inlet and outlet. The material first undergoes strong axial compression through the lower concave arc cavity 17 to achieve high orientation, and then enters the expansion region of the upper convex arc cavity 16. The radial compressive stress decreases, and the anisotropic stress distribution is partially relaxed, achieving a balance between axial orientation and cross-sectional density uniformity. The arc lengths are respectively... and .

[0042] (6) Composite contraction type with upper concave arc and lower convex arc (e.g.) Figure 2 (f) and Figure 5As shown): The lower generatrix curve near the inlet end 11 is a convex arc (parameters R4, X4), and the upper generatrix curve near the outlet end 12 is a concave arc (parameters R5, X5). The two segments satisfy the tangent continuity condition at the transition section. The design constraint R4 > R5, that is, the radius of curvature of the convex arc in the inlet segment is greater than the radius of curvature of the concave arc in the outlet segment, making the shrinkage rate of the inlet segment less than that of the outlet segment. After the material enters the die, it first undergoes a gentle initial shrinkage in the convex arc segment, with the cross-sectional area decreasing slowly to avoid excessive radial compressive stress at the inlet; then it enters the concave arc segment, where the shrinkage rate gradually increases, and the axial compression and radial constraint are simultaneously enhanced to achieve high axial orientation. This configuration is particularly suitable for materials that are sensitive to abrupt stress changes in the inlet segment, such as high-filled composite material preforms, fiber-reinforced plastic preforms, and brittle ceramic preforms. It can effectively avoid cracking defects caused by stress concentration at the inlet end, while obtaining an axial orientation close to that of a pure concave arc type at the outlet end. The arc lengths are respectively and In the embodiments, R4 is preferably 100~150mm, R5 is preferably 60~100mm, and the ratio of the diameter difference at the transition section to the diameter of the die inlet end does not exceed 15% to ensure a smooth transition of the flow channel under tangential continuity conditions.

[0043] (7) Composite type with upper outward convex arc and lower straight line (e.g.) Figure 2 As shown in (g): the upper generatrix curve near the outlet end 12 is a convex arc (parameters R8, X8), while the lower generatrix curve away from the outlet end is a straight line. The two sections are tangentially connected at the transition section. The material is first compressed at a uniform rate through the lower straight contraction section to establish a stable pre-compression state, and then enters the expansion region of the upper convex arc cavity to experience radial stress relaxation. This configuration combines the process stability of the straight type with the homogenization effect of the convex arc type, making it suitable for applications requiring both process window width and cross-sectional density uniformity. Arc length .

[0044] In an embodiment of the adaptive hydraulic control of this invention, each configuration of the die 2 is provided with a configuration identifier. The configuration identifier is preferably a radio frequency identification tag (RFID tag), embedded in the outer wall of the die 2, storing the configuration code of the die 2 (e.g., 01 corresponds to a straight-line contraction type, 02 corresponds to an outward-convex arc contraction type, and so on) and the curvature parameters (R value, X value, outward-convex arc R value, etc.) of the generatrix curve 13, as well as the historical cumulative number of pushes. The configuration identifier can also use other identification methods such as QR codes or barcodes.

[0045] Information reader 6 is installed on mold base 1. After die 2 is installed on mold base 1, information reader 6 automatically reads the information in the configuration identifier and transmits it to control unit 7. After receiving the configuration code, control unit 7 automatically retrieves the corresponding pressing pressure-stroke curve (PS curve) from the pre-stored process parameter library, and controls the output of servo hydraulic valve group 9 according to the curve, so that the pressure and speed of hydraulic lifting device 4 change in real time with the pushing stroke of material bar 5, realizing adaptive hydraulic control. Operators do not need to manually input process parameters, eliminating the risk of scrap caused by human error in parameter setting.

[0046] The establishment of the process parameter library relies on a three-dimensional process knowledge graph of configuration-material-performance (see [link]). Figure 4 The knowledge graph uses three dimensions: configuration encoding (horizontal axis, seven configurations), material type (vertical axis, such as polymer preforms, composite preforms, filled and modified materials, etc.), and target product performance indicators (depth axis, such as outer / inner diameter accuracy, cross-sectional density uniformity, axial orientation, etc.). Each matrix unit stores the optimal extrusion speed range, extrusion pressure range, and extrusion temperature range for the corresponding combination. When a certain configuration-material combination is used for the first time, the median value of each parameter range is used as the initial process parameters. After each extrusion, the measured product performance data is written into the knowledge graph, updating the parameter range of the corresponding unit, thus realizing the self-learning iterative optimization of the knowledge graph.

[0047] See Figure 3 For a composite die with an upper convex arc and a lower concave arc, the control unit 7 implements a two-stage control strategy to resolve the contradiction of drastically different flow characteristics when the material enters the convex arc expansion section from the concave arc compression section. Figure 3 In this context, P represents the pushing pressure, v represents the pushing velocity, and dP / dt represents the rate of change of the pushing pressure. This is the setpoint for steady-state extrusion pressure. This refers to the time for switching control modes.

[0048] Compression stage (concave arc segment): Hydraulic lifting device 4 operates at a constant speed (Calibrated by the process parameter library for the material type, generally less than 50% of the steady-state extrusion speed) The feed bar 5 is pushed upward through the lower concave arc cavity 17. The control unit 7 collects the extrusion pressure P(t) at a frequency of not less than 100Hz and calculates the rate of change of extrusion pressure dP / dt in real time within adjacent sampling intervals.

[0049] Stage switching judgment: When the material is under strong axial compression in the concave arc cavity 17, dP / dt remains at a high and stable level; when the material front crosses the transition section and enters the expansion region of the upper convex arc cavity 16, the effective cross-sectional area increases, the flow resistance decreases, and dP / dt drops significantly and falls below the preset switching threshold (calibrated by the process parameter library for specific material types). After the control unit 7 detects that dP / dt has dropped below the threshold, it determines that the material has entered the convex arc expansion section.

[0050] Steady-state extrusion stage: Control unit 7 in Within a time ( Switch the control mode from constant speed to constant pressure to maintain the extrusion pressure at the set value given in the process parameter library. After the material is uniformly filled in the expansion area of ​​the convex arc cavity 16, it is extruded from the outlet end 12 at a stable rate to obtain a product with uniform cross-sectional density. Constant pressure control avoids local overpressure or underpressure of the material in the expansion area of ​​the convex arc due to speed control.

[0051] Process safety assurance: During the compression stage (concave arc segment), if the extrusion pressure P exceeds the maximum safe extrusion pressure threshold for this configuration at the current extrusion temperature T stored in the process parameter library... The control unit 7 immediately stops pushing and sends an overpressure alarm signal to the operator to prevent the material bar 5 from breaking within the concave arc cavity 17. Maximum safe pushing pressure threshold. The compressive strength of the material at extrusion temperature T and the cross-sectional area of ​​the 17 bundles of the concave arc cavity are determined based on the different configurations. The values ​​differ significantly, and each configuration must be calibrated separately and stored in the process parameter library.

[0052] During each extrusion process, the pressure sensor and displacement sensor in sensor array 10 synchronously acquire the complete measured curve of extrusion pressure-stroke. The data is then stored in control unit 7. After extrusion is complete, control unit 7 will... The reference extrusion pressure-stroke curve calibrated in the new die state with the corresponding configuration stored in the process parameter library. Perform point-by-point comparisons and write the measured data into a three-dimensional process knowledge graph, such as... Figure 6 The diagram shows a comparison of the extrusion pressure-stroke curves. The solid line in the diagram represents the baseline extrusion pressure-stroke curve. The dashed line represents the measured curve of pushing pressure-stroke. ΔP is the pressure deviation between the baseline curve and the measured curve at the same stroke position, used to quantitatively characterize the degree of drift of the measured process state relative to the baseline process state. The actual process parameters and measured performance data of this extrusion are written into the three-dimensional process knowledge graph to update the process parameter range and realize the self-learning iterative optimization of the knowledge graph.

[0053] Example 1 (Extrusion of hollow tube blank using a linear shrinkage die): A linear shrinkage die 2 was selected, with an inlet end 11 inner diameter of 60mm, an outlet end 12 inner diameter of 6mm, a core outer diameter of 4mm, and a shrinkage half-angle θ of approximately 6.4°. A 60mm diameter, 2m long ultra-high molecular weight polyethylene (UHMWPE) rod was preheated to 25°C and placed on support column 3, aligning the rod 5 axis with the central axis of the die cavity. Information reader 6 read configuration code 01, and control unit 7 retrieved initial process parameters from the knowledge graph: extrusion speed 5m / min, extrusion pressure 5MPa, and extrusion temperature 25°C. The hydraulic lifting device 4 was activated, and continuous extrusion was performed using the above parameters to obtain a hollow tube product with an outer diameter of 6.5mm and an inner diameter of 4.1mm. The measured outer diameter tolerance was ±0.05mm, and the cross-sectional density uniformity was over 95%, verifying the process stability of the baseline configuration. Write the measured data (actual pressure curve, measured outer diameter 6.5mm / inner diameter 4.1mm) back into the knowledge graph to complete the initialization of the baseline curve for configuration 01 under this parameter combination.

[0054] Example 2 (High-orientation product extruded using a concave arc shrinkage die): A concave arc shrinkage die 2 was selected, with an inlet end 11 inner diameter of 60mm and an outlet end 12 inner diameter of 6mm. The radius of curvature R2 of the concave arc cavity 17 waist section was 100mm, and the central angle X2 was 14.33°. The arc length L2 was calculated using the arc length formula as 100×3.14159×14.33 / 180≈25.02mm. A UHMWPE rod of the same specifications as in Example 1 was preheated to 25°C, placed on the support column 3, and aligned with the die's central axis. The information reader 6 read the configuration code 03, and the control unit 7 retrieved the initial process parameters from the knowledge graph: extrusion speed 3m / min, extrusion pressure 18MPa, and extrusion temperature 30°C. After extrusion with the above parameters, the measured axial orientation of the product was approximately 25% higher than that of Example 1 (straight shrinkage type, same rod), and the axial compressive strength was approximately 20% higher, verifying the technical effect of the concave arc die in strengthening axial orientation. Write the measured data back into the knowledge graph to update the process parameters for configuration 03.

[0055] Example 3 (Homogeneous product extruded from a composite die with an outer convex arc on top and an inner concave arc on the bottom): A composite die 2 with an upper convex arc and a lower concave arc is selected. The parameters of the lower concave arc are R7=100mm and X7=14° (arc length L7=100×3.14159×14 / 180≈24.43mm), and the parameters of the upper convex arc are R6=90mm and X6=16° (arc length L6=90×3.14159×16 / 180≈25.13mm). The two sections are tangentially connected at the transition section (C). 1(Continuous). A glass fiber reinforced polyamide composite material rod (55mm in diameter) preheated to 30℃ is placed on support column 3 and aligned with the center axis of the die. Information reader 6 reads configuration code 05, and control unit 7 executes two-stage control: compression stage (concave arc segment) at a constant speed. The extrusion speed is m / min, and the pressure sensor collects P(t) at 100Hz and calculates dP / dt in real time. When dP / dt drops below the preset switching threshold of -2MPa / s (indicating that the material front has entered the outward convex arc expansion section), the control unit 7 switches to a constant pressure steady-state extrusion mode of 15MPa within 0.08s to complete the extrusion. The measured axial orientation of the product is about 15% higher than that of Example 1 (linear shrinkage type, same material), while the cross-sectional density uniformity is about 12% higher than that of Example 2 (pure inward concave arc type), verifying the technical effect of the composite type of upper outward convex arc and lower inward concave arc that takes into account both axial orientation and cross-sectional density uniformity.

[0056] Example 4 (Composite shrinkage die extrusion of symmetrical cross-section product with upper concave arc and lower straight line): A concave-arc-straight composite shrinkage die 2 was selected. The lower straight section had a shrinkage half-angle of approximately 10°, and the upper concave arc section had parameters R3=80mm and X3=20° (arc length L3=80×3.14159×20 / 180≈27.93mm). The two sections were tangentially connected at the transition section 18 (tangential continuity). A preheated 25°C polyetheretherketone (PEEK) rod (58mm in diameter) was placed on the support column 3. The information reader 6 read the configuration code 04, and the control unit 7 retrieved the initial process parameters of extrusion speed 4m / min, pressure 12MPa, and temperature 25°C and executed the extrusion. The measured axial orientation of the extruded product was approximately 15% higher than that of Example 1 (straight shrinkage type, same material), while the outer diameter tolerance of the extruded product was comparable to that of Example 1 (straight type) (±0.05mm), verifying the technical effect of the concave-arc-straight composite shrinkage type in simultaneously improving axial orientation and controlling dimensional accuracy. Write the measured data back into the knowledge graph to update the process parameters for configuration 04.

[0057] Example 5 (High-filler brittle composite material extruded using a shrinkage die with an upper concave arc and a lower convex arc): A composite shrinkage die 2 with an inward concave arc at the top and an outward convex arc at the bottom is selected. The inner diameter of the inlet end 11 is 60mm, and the inner diameter of the outlet end 12 is 6mm. The parameters of the outward convex arc of the lower section are R4=120mm and X4=15° (arc length L4=120×3.14159×15 / 180≈31.42mm), and the parameters of the inward concave arc of the upper section are R5=80mm and X5=18° (arc length L5=80×3.14159×18 / 180≈25.13mm), satisfying R4>R5. The two sections are tangentially connected at the transition section. A high-filling silicon carbide particle-reinforced polyimide composite material rod (58mm in diameter) preheated to 30℃ is placed on the support column 3. The information reader 6 reads the configuration code 06, and the control unit 7 retrieves the initial process parameters from the knowledge graph: extrusion speed 2m / min, extrusion pressure 15MPa, and extrusion temperature 30℃. After extrusion using the above parameters, the measured axial orientation of the product was approximately 20% higher than that of Example 1 (linear shrinkage type, same material), and close to that of Example 2 (concave arc type). However, no cracks were found on the inlet end surface of the product, whereas visible microcracks appeared on the inlet end surface when extruding the same highly filled brittle composite preform using a pure concave arc die. This verifies the effectiveness of the upper concave arc and lower convex arc composite shrinkage type in mitigating shrinkage at the inlet section to prevent brittle cracking. The measured data were written back to the knowledge graph to update the process parameters for configuration 06.

[0058] Example 6 (Extrusion product with wide process window using a composite die with an outward convex arc and a downward straight line): A composite die 2 with an outward convex arc at the top and a straight line at the bottom is selected. The inner diameter of the inlet end 11 is 60mm, and the inner diameter of the outlet end 12 is 6mm. The lower straight section has a contraction angle of approximately 8°, and the parameters of the outward convex arc of the upper section are R8=110mm and X8=12° (arc length L8=110×3.14159×12 / 180≈23.04mm). The two sections are tangentially connected at the transition section. A preheated 25℃ ultra-high molecular weight polyethylene (UHMWPE) rod (58mm in diameter) is placed on the support column 3. The information reader 6 reads the configuration code 07, and the control unit 7 retrieves the initial process parameters from the knowledge graph: extrusion speed 4m / min, extrusion pressure 8MPa, and extrusion temperature 25℃. After extrusion using the above parameters, the measured uniformity of the product cross-sectional density was improved by approximately 10% compared to Example 1 (pure linear shrinkage type, same material), and the sensitivity of the process parameters to extrusion speed fluctuations was reduced by approximately 40% compared to Example 2 (pure concave arc type). This verifies the technical effect of the composite type with an upper convex arc and a lower linear arc, which combines improved process stability and cross-sectional density uniformity. The measured data were written back to the knowledge graph to update the process parameters for configuration 07.

[0059] The above embodiments, while illustrating specific implementations of the present invention, also provide initial data points for the configuration-material-performance three-dimensional process knowledge graph. As production batches accumulate, the process parameter windows of each matrix unit in the knowledge graph will gradually narrow through self-learning updates, and the recommendation accuracy of the process parameters will continuously improve.

[0060] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A profile extrusion device, characterized in that, include: Mold base; A die, mounted on a die base, has an inner cavity extending along the extrusion direction, the inner cavity being formed by a generatrix curve, the generatrix curve including at least one arc segment; A support column is used to support the extruded bar, the axis of which is aligned with the central axis of the die cavity; A hydraulic lifting device, connected to a support column, is used to drive the material bar into the die cavity along the extrusion direction; The inner cavity configuration of the die is a composite type of upper convex arc and lower concave arc. The upper section generatrix curve near the exit end is an outward convex arc, and the lower section generatrix curve away from the exit end is a concave arc. The upper section generatrix curve and the lower section generatrix curve are tangentially connected at the transition section. The profile extrusion unit also includes configuration markers, information readers, pressure sensors, and control units; The configuration identifier is located on the die and stores the configuration code of the die; the information reader is installed on the die base and is used to read the configuration code; the pressure sensor is used to collect the pushing pressure signal in real time. The control unit is communicatively connected to the information reader, pressure sensor, and hydraulic lifting device. It retrieves the corresponding pressing pressure-stroke curve from a pre-stored process parameter library based on the configuration code, controls the output pressure and pushing speed of the hydraulic lifting device according to the pressing pressure-stroke curve, and performs two-stage control. During the compression stage, the hydraulic lifting device is controlled at a constant speed to push the bar upward through the concave arc cavity formed by the lower section generatrix curve, and the rate of change of the pushing pressure dP / dt is calculated based on the pushing pressure signal. When dP / dt is lower than the preset switching threshold, it is determined that the material front has entered the convex arc expansion area formed by the upper section of the bus curve, and the control mode is switched from constant speed to constant pressure to maintain steady-state extrusion with preset extrusion pressure.

2. The irregular shape extrusion device according to claim 1, characterized in that, The arc length L of the circular arc segment satisfies: , where R is the radius of curvature of the arc segment in mm, and X is the central angle of the arc segment in degrees.

3. The irregular shape extrusion device according to claim 1, characterized in that, The hydraulic lifting device has a pushing speed range of 0.02~100m / min and a pushing pressure range of 0.1~35MPa. The device also includes a temperature control unit, which is thermally connected to the die base and is used to maintain the working temperature of the die within the range of -20℃~150℃.

4. An extrusion method using the profile extrusion apparatus according to any one of claims 1-3, characterized in that, Specifically, the following steps are included: S1. Place the material bar on the support column, aligning the axis of the material bar with the central axis of the die cavity, wherein the die cavity is formed by a generatrix curve containing at least one arc segment. S2. Obtain the configuration code of the die; S3. Determine the extrusion process parameters based on the configuration code; S4. Start the hydraulic lifting device and drive the bar into the die cavity according to the process parameters determined in step S3. After the bar is formed in the die cavity, it is extruded from the outlet end to obtain the product.

5. The extrusion method of the irregular shape extrusion device according to claim 4, characterized in that, The specific process for determining the extrusion process parameters in step S3 is as follows: Using configuration code, material type and target product performance index as query keys, query and obtain the corresponding extrusion speed range, extrusion pressure range and extrusion temperature range in the configuration-material-performance three-dimensional process knowledge graph, and use the median value of each range as the initial process parameters. After extrusion, the measured product performance data is compared with the target product performance indicators, and the actual extrusion process parameters and measured performance data are written into the three-dimensional process knowledge graph to update the corresponding process parameter range.

6. An electronic device, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement an extrusion method for a profile extrusion apparatus as described in any one of claims 4-5.

Images