A multi-zone independent temperature-controlled carbon fiber composite hot pressing press

Abstract

The present application relates to the technical field of carbon fiber composite materials, and particularly relates to a multi-zone independent temperature control carbon fiber composite material hot press forming press, which comprises a body frame structure, an electric box, a movable operating platform, a liquid charging tank and a hydraulic drive system; the hydraulic drive system comprises a main cylinder one, a main cylinder two, a liquid charging valve and a servo motor; a hydraulic bolt safety cylinder is arranged between an upper cross beam and a movable cross beam; the multi-zone independent temperature control carbon fiber composite material hot press forming press further comprises a partition heating system, the partition heating system comprises an upper heating plate and a lower heating plate which are respectively integrated on the movable cross beam and the lower cross beam, the surfaces of the upper heating plate and the lower heating plate are divided into N independent temperature control zones, each independent temperature control zone comprises a silicon carbide-based embedded heating element, a distributed thermocouple array and a ring-shaped heat insulation groove, the multi-zone independent temperature control carbon fiber composite material hot press forming press significantly improves the quality consistency and production efficiency of carbon fiber composite material products, and reduces energy consumption and maintenance cost.

Description

Technical Field

[0001] This invention relates to the field of carbon fiber composite materials technology, and in particular to a multi-zone independently temperature-controlled carbon fiber composite hot pressing press. Background Technology

[0002] Carbon fiber composites, due to their high strength, lightweight, and corrosion resistance, are widely used in aerospace, automotive manufacturing, and high-end equipment. Hot pressing, as a core manufacturing process, requires curing the prepreg resin under high temperature and pressure. The uniformity of the temperature field, the precision of pressure control, and process safety directly determine the mechanical properties and yield of the final product. However, existing hot pressing equipment still suffers from technical deficiencies when manufacturing large-size, complex structural components, including insufficient temperature uniformity, low hydraulic control precision, and short lifespan of heating components. To address these shortcomings, this patent proposes a multi-zone independent temperature-controlled carbon fiber composite hot pressing press. This press integrates high-precision temperature control, adaptive hydraulic drive, and intelligent safety protection, significantly improving the quality consistency and production efficiency of carbon fiber composite products while reducing energy consumption and maintenance costs. Summary of the Invention

[0003] The purpose of this invention is to solve the problems existing in the prior art by proposing a multi-zone independent temperature-controlled carbon fiber composite hot pressing press.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A multi-zone independent temperature-controlled carbon fiber composite hot pressing press includes a frame structure, an electrical control box, a movable operating platform, a filling tank, and a hydraulic drive system. The electrical control box and the movable operating platform are located on one side of the frame structure. The frame structure comprises an upper crossbeam, a lower crossbeam, a movable crossbeam, and four columns connected by prestressed fixing nuts. A laser calibration reference surface is provided on the surface of the columns. The hydraulic drive system includes a main cylinder, a second main cylinder, a filling valve, and a servo motor. The first and second main cylinders are rigidly connected to the movable crossbeam via pistons. A hydraulic safety cylinder with a pin is installed between the upper and movable crossbeams. The filling tank is located on one side of the upper crossbeam. The press also includes a zone heating system. The partitioned heating system includes an upper heating plate and a lower heating plate integrated on a movable crossbeam and a lower crossbeam, respectively. The surfaces of the upper and lower heating plates are divided into N independent temperature control zones. Each independent temperature control zone includes a silicon carbide-based embedded heating element, a distributed thermocouple array, and an annular heat insulation groove. The annular heat insulation groove is filled with nanoporous silica aerogel. Temperature uniformity in each independent temperature control zone is achieved through a multivariate predictive control algorithm. A safety light curtain, consisting of an infrared transmitter and receiver array, is also provided at the edge of the lower heating plate. When a foreign object is detected entering the working area, the equipment is triggered to stop urgently. The mold-moving arm is mounted on the side of the lower heating plate via a linear guide rail and is driven by a servo motor.

[0006] Furthermore, the multivariate predictive control algorithm satisfies:

[0007] ,

[0008] in, Indicates the proportion term, Indicates the integral term, Representing differential terms, Indicates thermal coupling terms, Represents the gradient compensation term. The thermal coupling coefficient between adjacent independent temperature-controlled areas is calibrated using an offline thermal imager. K represents the real-time heating power of the i-th independent temperature control zone to achieve the target temperature control. p K i K d Indicates PID parameters; ΔT represents the deviation between the target temperature and the actual temperature of the i-th independent temperature-controlled zone. i (t)=T target -T i (t), This represents the thermal coupling compensation term for adjacent independent temperature control zones; where T target It is the global target temperature, T i(t) is the real-time temperature of the i-th independent temperature control zone, a ij T represents the thermal coupling coefficient between the j-th independent temperature control zone and the i-th independent temperature control zone, reflecting the intensity of heat transfer; j T i : These represent the real-time temperatures of the j-th and i-th independent temperature control zones, respectively. This represents the second-order temperature gradient compensation term, where β represents the compensation factor, used to suppress non-uniform heat dissipation at the edges of each independent temperature-controlled region. It represents the second derivative of the real-time temperature in space, and represents the curvature of the temperature field. It is used to reduce abrupt temperature gradient changes caused by heat dissipation in the edge region. It is achieved through thermocouple array measurement or discrete approximation to improve the uniformity of temperature across the entire region.

[0009] Furthermore, the upper heating plate and the lower heating plate are sandwich composite structures, including a load-bearing layer, a heat-equalizing layer and a functional layer, wherein the load-bearing layer is a tungsten carbide reinforced copper-based composite material.

[0010] Furthermore, the guiding mechanism of the movable crossbeam includes: four sets of double V-shaped roller guides, an embedded piezoelectric force sensor, and a hydraulic servo system, which adjusts the cylinder pressure distribution in real time according to the following formula:

[0011] ,

[0012] in, This represents the real-time output pressure of the k-th cylinder, in Newtons (N). The average pressure reference value of all cylinders is expressed in Newtons (N); R is the equivalent distribution radius of the cylinder force, expressed in meters (m); Δθ is the angular deviation between the actual inclination angle of the movable crossbeam and the ideal horizontal plane, expressed in radians (rad); E is the elastic modulus of the movable crossbeam material, expressed in Pascals (Pa) or N / m²; and I is the moment of inertia of the movable crossbeam section, expressed in meters. 4 (m) 4 L represents the guide rail span, in meters (m), and φ represents the guide rail span. k This represents the azimuth angle of the k-th cylinder, expressed in radians (rad) or degrees (°). This represents the sine value of the azimuth angle of the Kth cylinder, in dimensionless form. This represents the average value of the sine values ​​of the azimuth angles of the four hydraulic cylinders, in dimensionless form. This is the orientation correction factor, and its unit is dimensionless.

[0013] Furthermore, the heat spreader is a directionally arranged graphene sheet with an in-plane thermal conductivity ≥2000W / m·K, and a vertical carbon nanotube array is grown between the layers by chemical vapor deposition (CVD).

[0014] Furthermore, a TiAlN hard coating is deposited on the surface of the functional layer by magnetron sputtering to improve its wear resistance and anti-adhesion properties; a transition layer is added between the heat spreader and the functional layer, and the transition layer has a gradient composite structure, consisting of the following components from bottom to top:

[0015] Copper-graphene hybrid layer, nanodiamond dispersion layer.

[0016] Furthermore, the cross-section of the annular heat insulation groove is trapezoidal, and the width of the groove bottom is 0.6-0.8 times the width of the groove opening; the groove spacing is arranged according to the modified Fibonacci sequence: d n =1.618d n-1 -0.618d n-2 The initial spacing is: d1 ranges from 12mm to 17mm, d2 ranges from 23mm to 27mm, the bottom fillet radius r ≥ 0.3w, and the inclination angle of the tank wall θ = 45 ± 2°.

[0017] Furthermore, the hydraulic drive system applies dynamic pressure disturbances according to the curing process curve, and its pressure... satisfy:

[0018] ,

[0019] in, This indicates the real-time output pressure of the hydraulic system, measured in Pascals (Pa). The reference pressure setting curve is shown, with units in Pascals (Pa). The coefficient representing the fluctuation amplitude of dynamic pressure is dimensionless, and t represents the process time in seconds (s). The period of dynamic pressure fluctuation is expressed in seconds (s). It is represented as a sinusoidal periodic function with dimensionless units, and the dynamic pressure is used to suppress the formation of interlayer bubbles.

[0020] Furthermore, the distributed thermocouple array is arranged such that the thermocouples are arranged in a hexagonal grid within each independent temperature control area.

[0021] Compared with existing technologies, the advantages of this invention are:

[0022] This invention proposes a multi-zone independent temperature-controlled carbon fiber composite hot pressing press, which integrates high-precision temperature control, adaptive hydraulic drive and intelligent safety protection. This significantly improves the quality consistency and production efficiency of carbon fiber composite products, while reducing energy consumption and maintenance costs. Attached Figure Description

[0023] Figure 1This is a three-dimensional structural diagram of the carbon fiber composite hot pressing press in this invention;

[0024] Figure 2 This is a front view of the carbon fiber composite hot pressing press in this invention;

[0025] Figure 3 This is a side view of the hot pressing press for carbon fiber composite materials in this invention.

[0026] In the diagram: 1-Upper crossbeam; 2-Lower crossbeam; 3-Modible crossbeam; 4-Column; 5-Main cylinder one; 6-Main cylinder two; 7-Filling valve; 8-Servo motor; 9-Hydraulic safety cylinder; 10-Upper heating plate; 11-Lower heating plate; 12-Safety light curtain; 13-Moving mold arm; 14-Electrical box; 15-Moving operating table; 16-Filling tank. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1, such as Figure 1-3As shown, a multi-zone independent temperature-controlled carbon fiber composite hot pressing press includes a frame structure, an electrical box 14, a movable operating platform 15, a filling tank 16, and a hydraulic drive system. The electrical box 14 and the movable operating platform 15 are located on one side of the frame structure. The frame structure includes an upper crossbeam 1, a lower crossbeam 2, a movable crossbeam 3, and four columns 4 connected by prestressed fixing nuts. A laser calibration reference surface is provided on the surface of the columns 4. The hydraulic drive system includes a first main cylinder 5 and a second main cylinder 6. The hydraulic valve 7 and servo motor 8 are included; main cylinder 5 and main cylinder 6 are rigidly connected to the movable crossbeam 3 via main cylinder pistons; a hydraulic safety cylinder 9 is provided between the upper crossbeam 1 and the movable crossbeam 3; the filling tank 16 is located on one side of the upper crossbeam 1. In this embodiment, the upper crossbeam 1, lower crossbeam 2, movable crossbeam 3, electrical box 14, movable operating platform 15, filling tank 16, and main cylinder 5, main cylinder 6, filling valve 7, and servo motor 8 in the hydraulic drive system described above are all existing technical solutions and will not be discussed further here. A more detailed explanation is provided, which also includes a zoned heating system. This system comprises an upper heating plate 10 and a lower heating plate 11 integrated onto the movable crossbeam 3 and lower crossbeam 2, respectively. The surfaces of the upper heating plate 10 and lower heating plate 11 are divided into N independent temperature-controlled zones. Each zone contains a silicon carbide-based embedded heating element with a power density of 50-200 W / cm²; a distributed thermocouple array with a measurement point density ≥4 / 100cm²; and an annular heat-insulating groove with a width of 1.0±0.2mm and a depth of 3mm. The annular heat insulation groove is filled with nanoporous silica aerogel; the global temperature uniformity σ≤1.0℃ is achieved through a multivariate predictive control algorithm; a safety light curtain 12 is also provided at the edge of the lower heating plate 11, which is composed of an infrared transmitter and receiver array. The safety light curtain 12 has a coverage height of 50-150mm and a response time ≤10ms. When a foreign object is detected to have entered the working area, the equipment is triggered to stop urgently; the mold moving arm 13 is installed on the side of the lower heating plate 11 via a linear guide rail and is driven by a servo motor 8.

[0029] In the above embodiment, the core components of the hydraulic drive system are a dual-cylinder design, main cylinder 5 and main cylinder 6, which are symmetrically arranged. The pistons of the main cylinders are rigidly connected to the movable groove beam 3 via flanges. In this embodiment, there are two filling valves 7, symmetrically arranged on one side of main cylinder 5 and main cylinder 6, respectively, to achieve rapid oil replenishment for main cylinders 5 and 6. A servo motor 8 drives a high-pressure gear pump with a pressure control accuracy of ±0.5MPa. Satisfying the pressure fluctuation formula:

[0030] ,

[0031] in, This indicates the real-time output pressure of the hydraulic system, measured in Pascals (Pa). The reference pressure setting curve is shown, with units in Pascals (Pa). The coefficient representing the fluctuation amplitude of dynamic pressure is dimensionless, and t represents the process time in seconds (s). The period of dynamic pressure fluctuation is expressed in seconds (s). It is represented as a sinusoidal periodic function with dimensionless units, and the dynamic pressure is used to suppress the formation of interlayer bubbles.

[0032] When T=15S (adapted to epoxy resin viscosity), the zoned heating system has a heating plate structure. In this embodiment, the heating plate structure includes an upper heating plate 10 and a lower heating plate 11. The surfaces of the upper heating plate 10 and the lower heating plate 11 are divided into 24 independent temperature control zones (honeycomb arrangement). Each zone is equipped with: silicon carbide-based heating elements: power density 150W / cm², arranged in concentric ring gradients (outer ring density +10%); silicon carbide-based heating elements: power density 150W / cm², arranged in concentric ring gradients (outer ring density +10%); and an annular heat insulation groove: groove width 1.0mm, depth 3mm, filled with nanoporous silica aerogel (thermal conductivity 0.018W / m·K). Through a multivariate predictive control algorithm, the following conditions are met:

[0033] ,

[0034] in, Indicates the proportion term, Indicates the integral term, Representing differential terms, Indicates thermal coupling terms, Represents the gradient compensation term. The thermal coupling coefficient between adjacent independent temperature-controlled areas is calibrated using an offline thermal imager. K represents the real-time heating power of the i-th independent temperature control zone to achieve the target temperature control. p K i K d Indicates PID parameters; ΔT represents the deviation between the target temperature and the actual temperature of the i-th independent temperature-controlled zone. i (t)=T target -T i (t), This represents the thermal coupling compensation term for adjacent independent temperature control zones; where T target It is the global target temperature, T i (t) is the real-time temperature of the i-th independent temperature control zone, a ij T represents the thermal coupling coefficient between the j-th independent temperature control zone and the i-th independent temperature control zone, reflecting the intensity of heat transfer; j Ti : These represent the real-time temperatures of the j-th and i-th independent temperature control zones, respectively. This represents the second-order temperature gradient compensation term, where β represents the compensation factor, used to suppress non-uniform heat dissipation at the edges of each independent temperature-controlled region. It represents the second derivative of the real-time temperature in space, and represents the curvature of the temperature field. It is used to reduce abrupt temperature gradient changes caused by heat dissipation in the edge region. It is achieved through thermocouple array measurement or discrete approximation to improve the uniformity of temperature across the entire region.

[0035] The algorithm parameters are configured as shown in Table 1 below:

[0036] parameter symbol Value effect Calibration form PID parameters <![CDATA[K p ]]> 8.5 W / ℃ Fast response temperature deviation Ziegler-Nichols tuning PID parameters <![CDATA[K i ]]> 0.4 W / (℃·s) Eliminate steady-state error Critical Proportioning Method PID parameters <![CDATA[K d ]]> 1.2 W·s / ℃ Suppressing temperature overshoot Step response curve fitting thermal coupling coefficient <![CDATA[a ij ]]> 0.03-0.15 W / (℃·m) Compensation for heat transfer in adjacent areas Infrared thermal imager calibration (Table 2) Gradient compensation factor β 0.12 W·m² / ℃ Suppressing edge heat dissipation compensation Finite element simulation optimization

[0037] Table 2: Thermal coupling coefficient a ij Calibration example (center partition i=12)

[0038] Adjacent partition j <![CDATA[Distance d ij (mm)]]> <![CDATA[Temperature rise ΔT j (°C)]]> <![CDATA[Calculated value a ij > <![CDATA[Optimized value a ij > j=3 (left) 200 4.2 0.042 0.038 j=11 (above) 200 3.8 0.038 0.035 j=13 (right) 200 4.5 0.045 0.041 j=21 (below) 200 3.6 0.036 0.033

[0039] Algorithm execution flow:

[0040] Data acquisition: Real-time reading of thermocouple temperatures T in 24 zones i (t) (sampling frequency 10Hz);

[0041] The infrared thermal imager simultaneously scans the temperature field (spatial resolution 0.5 mm / pixel).

[0042] Deviation calculation:

[0043] (Target temperature 108℃).

[0044] Calculate the second derivative (Δx=200mm).

[0045] Power output: P is calculated in real time according to the formula. i (t), output to LLC resonant power supply; solid-state relay switching control, response time ≤1μs.

[0046] Table 3 Experimental data:

[0047] Test conditions: 1.8m × 2.4m aerospace-grade carbon fiber prepreg (T800 / epoxy resin), molding temperature 180±2℃

[0048] Control strategy Maximum temperature difference (°C) Average temperature difference (°C) Global temperature uniformity σ (°C) Energy consumption (kWh) Traditional PID control 8.5 3.2 2.8 85.6 This algorithm (without a beta term) 4.1 1.5 1.2 78.3 This algorithm (complete) 2.3 0.7 0.9 72.1

[0049] Beneficial effects demonstrated: Edge region optimization: Second-order gradient compensation term ( This reduces the temperature deviation of edge zones (such as zones 1 and 24) by 60% (compared to no compensation); the energy-saving effect achieved is that thermal coupling compensation reduces ineffective heating and reduces overall energy consumption by 15.8%.

[0050] This embodiment uses high-precision parameter configuration (Table 1) and thermal coupling coefficient a. ij Calibration (Table 2) and experimental data verification (Table 3) demonstrate the engineering feasibility of the algorithm described in the embodiments. Experimental data (Table 3) proves that it significantly improves global temperature uniformity and reduces energy consumption, making it particularly suitable for high-quality manufacturing of large composite material components for aerospace applications.

[0051] In Example 2, the upper heating plate 10 and the lower heating plate 11 are sandwich composite structures, including a load-bearing layer, a heat-equalizing layer and a functional layer. The load-bearing layer is a tungsten carbide-reinforced copper-based composite material, the heat-equalizing layer is a directionally arranged graphene sheet, and the functional layer is a plasma-sprayed Al2O3-TiO2 composite coating.

[0052] In this embodiment, the material of the load-bearing layer in the sandwich composite structure is: tungsten carbide reinforced copper matrix composite material, with a tungsten carbide volume fraction of 45% and a copper matrix composition of Cu-0.8wt%Cr-0.3wt%Zr (for reinforcing interfacial bonding); thickness: 18mm; performance parameters are shown in Table 4 below:

[0053] Performance indicators numerical values coefficient of thermal expansion <![CDATA[(4.6±0.2)×10 -6 / ℃]]> flexural strength ≥850 MPa Thermal conductivity (200℃) 210 W / m·K

[0054] The heat spreader in this embodiment:

[0055] The heat spreader is made of oriented graphene sheets. In this embodiment, the number of graphene sheets is 120, the orientation accuracy is ≤5° (XRD test), and the thickness is 0.15mm.

[0056] Enhanced design: Interlayer vertically grown carbon nanotube array (diameter 8nm, density 5×10⁻⁶) 10 Thermal conductivity: 75 W / m·K (without reinforcement layer: <20 W / m·K)

[0057] Table 5: Thermal diffusivity

[0058] direction Thermal conductivity (W / m·K) In-plane (XY) 2200 Thickness (Z) 80

[0059] Functional layer:

[0060] In this embodiment, the material of the functional layer is a plasma-sprayed Al2O3-20wt%TiO2 composite coating with a thickness of 150±10μm;

[0061] Spraying process parameters table 6:

[0062] parameter numerical values Spraying power 40 kW Powder delivery rate 40 g / min Argon flow rate 45 L / min Spraying distance 120 mm

[0063] Surface performance indicators Table 7:

[0064] index numerical values Roughness Ra 0.45 μm Microhardness 1250 HV0.3 coefficient of friction 0.18 (vs carbon fiber)

[0065] Preparation process flow:

[0066] (1) Fabrication of the bearing layer

[0067] Powder metallurgy:

[0068] Mixed powder: WC powder (particle size 3μm) + Cu-Cr-Zr alloy powder (particle size 15μm);

[0069] Hot pressing sintering: 950℃ / 35MPa / 2h → Density ≥99.2%

[0070] Precision machining: Surface grinding to flatness ≤0.01mm / m

[0071] (2) Bonding of the heat exchange layer

[0072] Graphene orientation: CVD growth of monolayer graphene on copper foil surface → stacking 120 layers → hot pressing in a 20T magnetic field (400℃ / 10MPa);

[0073] Etching and shaping:

[0074] FeCl3 solution etching of copper substrate → obtaining self-supporting graphene sheets

[0075] CNT enhancement: Surface deposition of Ni catalyst → CVD growth of vertical carbon nanotubes (700℃ / C2H4)

[0076] (3) Functional layer spraying

[0077] Matrix pretreatment: Sandblasting (Al2O3 sand, 60 mesh) → Surface roughness Rz = 40 μm

[0078] Plasma spraying: using a Metco 3MB spray gun, Al2O3-TiO2 composite powder (particle size 15-45μm).

[0079] Laser remelting: 1064nm pulsed laser (energy density 25J / cm²) → porosity reduced to 2%.

[0080] Technical Effect Verification Table 8: Comparison of Thermal Uniformity

[0081] heating plate type Center-edge temperature difference (180℃ operating condition) Time to heat up to 300℃ Traditional stainless steel heating plate 12.5℃ 45 min This embodiment features a composite structure. 2.3℃ 28 min

[0082] Service life test table 9:

[0083] Fatigue test: 1000 consecutive thermal cycles (room temperature ↔ 300℃)

[0084] Performance degradation Traditional heating plate Structure of this embodiment Surface warping deformation 0.8 mm / m 0.05 mm / m thermal conductivity decrease rate 18% ≤3% Percentage of coating peeling area 15% ＜0.5%

[0085] In this embodiment, the high-temperature deformation problem is solved by powder metallurgy strengthening (WC-Cu-Cr-Zr) of the load-bearing layer; the oriented graphene + vertical CNT design of the heat-spreading layer achieves ultra-high thermal conductivity; and the plasma spraying + laser remelting process of the functional layer obtains a highly wear-resistant and non-stick surface. The synergistic effect of the three technologies increases the life of the heating plate by 5 times and achieves internationally leading temperature uniformity, providing core technical support for the high-quality molding of large-size carbon fiber components.

[0086] Example 3, based on Example 1 above, the guiding mechanism of the movable crossbeam 3 includes: four sets of double V-shaped roller guides, an embedded piezoelectric force sensor, and a hydraulic servo system that adjusts the cylinder pressure distribution in real time according to the following formula:

[0087] ,

[0088] in, This represents the real-time output pressure of the k-th cylinder, in Newtons (N). The average pressure reference value of all cylinders is expressed in Newtons (N); R is the equivalent distribution radius of the cylinder force, expressed in meters (m); Δθ is the angular deviation between the actual inclination angle of the movable channel beam and the ideal horizontal plane, expressed in radians (rad); E is the elastic modulus of the movable crossbeam material, expressed in Pascals (Pa) or N / m²; I is the moment of inertia of the movable crossbeam 3, expressed in meters (m⁴); L is the span of the guide rail, expressed in meters (m); φ k This represents the azimuth angle of the k-th cylinder, expressed in radians (rad) or degrees (°). This represents the sine value of the azimuth angle of the Kth cylinder, in dimensionless form. This represents the average value of the sine values ​​of the azimuth angles of the four hydraulic cylinders, in dimensionless form. This is the orientation correction factor, and its unit is dimensionless.

[0089] In the above embodiment, the dynamic pressure distribution of the guide mechanism of the movable crossbeam 3 is implemented as follows:

[0090] 1. Hardware configuration of the guiding mechanism:

[0091] Double V-shaped roller guide: four sets, single rail preload 500±10N, friction coefficient ≤0.003;

[0092] Embedded piezoelectric force sensor (model PCB 260A01):

[0093] Measurement range: 0-50 kN, resolution: 0.1 N

[0094] Installation location: 8 measuring points are evenly distributed around the circumference of the guide rail slider (at 45° intervals).

[0095] Servo hydraulic cylinders: 4 independent cylinders (stroke ±5mm, response time ≤10ms)

[0096] 2. Implementation of the pressure distribution algorithm:

[0097] (1) Formula parameter definition table 10:

[0098]

[0099] In this embodiment, the above formula can be understood as final pressure = base press + correction pressure. It primarily provides the main pressure required for the process. Used to keep the beam level. This part calculates the corrective bending moment (in N·m) required to counteract the currently detected tilt angle Δθ. The stiffer the beam (larger E*I) and the shorter the span (smaller L), the greater the bending moment required to produce the same angular deviation.

[0100] / R Divide the above corrective bending moment by the distribution radius R to convert it into the concept of a total corrective force.

[0101] Finally, this total corrective force is distributed proportionally to the four cylinders according to the azimuth angle of each cylinder. This distribution method ensures that the sum of the force changes of the four cylinders is zero (i.e., it does not affect the total pressure), but generates a pure torque to precisely correct the tilt of the beam.

[0102] In this embodiment, a very advanced, physical model-based decoupling control algorithm is used, which not only eliminates errors (tilt), but also clearly knows how to allocate control quantities (cylinder pressure) in the most efficient and accurate way to achieve this goal.

[0103] Example 4 continues the above examples, with the heat spreader being oriented graphene sheets. The in-plane thermal conductivity of the graphene sheets is ≥2000 W / m·K. Vertical carbon nanotube arrays are grown between the sheets using chemical vapor deposition (CVD). In this example, graphene is a known material with extremely high in-plane thermal conductivity (theoretically up to 5000 W / m·K). The requirement of ≥2000 W / m·K is an extremely high value, achievable through oriented alignment, far exceeding that of common metals (copper approximately 400 W / m·K). This ensures extremely rapid lateral heat diffusion within the heat spreader, a key performance indicator for achieving "heat spreader" and "independent temperature control." Secondly, the interlayer thermal conductivity between graphene sheets is typically low. Growing vertical carbon nanotube (CNT) arrays between the sheets using CVD solves the bottleneck of interlayer heat transport. CNTs also have extremely high axial thermal conductivity, which can efficiently transfer heat from one layer of graphene to the next layer like a "thermal bridge", thus constructing a three-dimensional ultra-high thermal conductivity network (graphene in the plane and CNTs between layers). The solution in this embodiment is not a simple material replacement, but fundamentally improves the performance of the heat spreader through micro-nano structure design (directional arrangement + vertical arrangement), which is highly innovative.

[0104] Example 5, continuing from the above examples, further deposits a TiAlN hard coating on the surface of the functional layer by magnetron sputtering. The coating has a thickness of 2-5 μm, a hardness ≥2800 HV, and a friction coefficient ≤0.15, to improve wear resistance and anti-adhesion performance. A transition layer is added between the heat spreader and the functional layer. The transition layer has a gradient composite structure, consisting of the following components from bottom to top:

[0105] The copper-graphene hybrid layer has a thickness of 0.2-0.5 mm, and the nanodiamond dispersion layer has a thickness of 50-100 μm; the thermal conductivity of the gradient composite structure gradually changes from 800 W / m·K to 1500 W / m·K from bottom to top.

[0106] In this embodiment, the functional TiAlN coating layer and the gradient transition layer are implemented in a coordinated manner:

[0107] In this embodiment, the gradient transition layer is constructed as follows:

[0108] Gradient structure design table 11:

[0109] Layer Material composition thickness thermal conductivity Lower layer (near the heat exchanger) Cu + 10 vol% graphene 0.4mm 810±20 Middle layer Cu + 5 vol% graphene + 3 vol% nanodiamond 70μm 1120±30 Upper layer (near functional layer) Cu + 2 vol% graphene + 8 vol% nanodiamond 100μm 1470±40

[0110] Key processes:

[0111] A copper-graphene hybrid layer exhibits good compatibility with the copper-based support layer. Furthermore, the introduced graphene complements the composition of the heat spreader, achieving a transition from metal to carbon materials.

[0112] Powder metallurgy: Cu powder (5μm) + graphene sheets (1-3 layers, 20μm in diameter) are ball-milled and mixed → hot-pressed (850℃ / 30MPa).

[0113] Graphene orientation control: Cooled in a 1.5T magnetic field, orientation degree ≥90% (XRD half width at half maximum ≤0.5°)

[0114] Nanodiamond dispersion layer: Nanodiamond is sp³ bonded carbon, and its ultra-high hardness, thermal conductivity, and chemical stability make it a perfect bridge connecting the carbon material substrate and the TiAlN coating.

[0115] Diamond surface modification:

[0116] Pickling (H2SO4:HNO3=3:1) → Surface carboxylation;

[0117] Silane coupling agent (KH550) treatment → improves copper interface wettability;

[0118] In this embodiment, a TiAlN nanocomposite coating (3250HV + 0.11 friction coefficient) is used to solve high-temperature adhesion; a three-level gradient transition layer (thermal conductivity 810 → 1470 W / m·K) eliminates interfacial thermal stress; and surface energy synergistic design (28.6mJ / m²) reduces carbon fiber peeling force by 90%. The combination of these three factors enables the equipment to exceed 10,000 cycles under high-temperature conditions of 320℃, providing technical support for the mass production of high-performance composite materials.

[0119] In this embodiment, TiAlN (titanium aluminum nitride) coating is one of the mainstream varieties of PVD (physical vapor deposition) hard coatings recognized internationally. Magnetron sputtering is the most standard and mature industrial technology in this field, and TiAlN coatings have extremely high hardness (typically reaching HV). With a surface temperature of 3000°C or higher, it can effectively resist abrasive wear and scratches caused by frequent loading and unloading of carbon fiber prepreg and molds, greatly extending the life of the heating plate working surface. Its chemical properties are stable, its surface energy is relatively low, and it can form a dense alumina film, which can effectively prevent the adhesion of epoxy resin or other polymer matrix during high-temperature molding, ensure smooth demolding of products, and improve the surface quality of products. Its performance is stable at high temperatures (up to 800-900°C), making it very suitable for the high-temperature working environment of hot pressing. Magnetron sputtering is a low-temperature PVD technology that can prepare a TiAlN coating with good adhesion and dense uniformity at a temperature that does not damage the bottom material and structure of the heating plate. In this embodiment, the functional layer (TiAlN coating) and the underlying heat spreader layer (graphene / CNT) or the support layer (copper-based composite material) have huge differences in physical properties (such as the coefficient of thermal expansion). Direct bonding is prone to coating failure due to stress during thermal cycling. The gradient transition layer—a copper-graphene hybrid layer and a nanodiamond dispersion layer—fundamentally solves the technical challenge of bonding multilayer heterogeneous materials, ensuring the reliability of the entire heating plate under long-term thermo-mechanical coupling. This solution not only proposes a surface coating but also proactively designs a gradient transition layer to address interface bonding issues, demonstrating a high level of systematic engineering design thinking.

[0120] Example 6: The cross-section of the annular heat insulation groove is trapezoidal, and the width of the groove bottom is 0.6-0.8 times the width of the groove opening; the groove spacing is arranged according to the modified Fibonacci sequence: d n =1.618d n-1 -0.618d n-2 The initial spacing is d1, which ranges from 12mm to 17mm, and d2, which ranges from 23mm to 27mm. The radius of the bottom fillet r is greater than or equal to 0.3w, and the inclination angle of the groove wall is θ = 45 ± 2°, where w is the width of the groove opening.

[0121] In the above embodiments, the parameter design table 12 for the heat insulation groove structure is as follows:

[0122] parameter Technical Requirements This embodiment implements the value. effect Cross-sectional shape trapezoid Top / bottom = 1.0mm / 0.7mm Enhance structural stability groove depth 3mm 3.0±0.1mm Blocking lateral heat conduction <![CDATA[Width w1 of the groove bottom]]> <![CDATA[w1=(0.6~0.8)w0]]> <![CDATA[w1=0.72w0]]> Reduce stress concentration slot width w 1.0±0.2mm 1.05mm Compatible aerogel filling process Tank wall inclination angle 45±2° 46.5° Optimize the thermal barrier ratio (insulation / strength). Rounded corners at the bottom of the groove r≥0.3w r=0.35mm To avoid crack formation

[0123] Cross-sectional characteristics: The height-to-depth ratio of the trapezoid is h / w = 2.86 (ideal value 2.5-3.0), and the inclination angle θ of the groove wall and the fillet radius r form a continuous curvature transition;

[0124] Layout rules:

[0125] Modified Fibonacci sequence:

[0126] Initial value table 13:

[0127] Serial Number Formula calculation The value in this embodiment Allowable error <![CDATA[d1]]> — 15.2mm 12-17mm <![CDATA[d2]]> — 24.8mm 23-27mm <![CDATA[d3]]> 1.618×24.8-0.618×15.2=30.7mm 30.3mm ±0.5mm <![CDATA[d4]]> 1.618×32.5-0.618×24.8=37.3mm 37.6mm ±0.5mm

[0128] Advantages of this layout:

[0129] 1. Non-equidistant arrangement disrupts the regular heat flow path, reducing lateral thermal conductivity by 30%;

[0130] 2. The golden ratio (1.618) optimizes stress distribution, reducing thermal deformation by 45%;

[0131] Key steps in the manufacturing process:

[0132] 1. Laser precision mesh:

[0133] Equipment: Laser (wavelength 355mm, pulse energy 50μJ)

[0134] Parameters: Scanning speed 200mm / s, repetition frequency 100kHz → groove wall roughness Ra≤1.6μm;

[0135] 2. Aerogel filling:

[0136] Material: Hydrophobic nano-SiO2 aerogel (pore size 20-50nm)

[0137] Process: Vacuum infusion (-0.1MPa) → Filling density ≥98%

[0138] 3. Rounding corner strengthening treatment: micro-shot peening treatment (glass bead particle size 50μm) → the compressive stress at the bottom of the tank is increased to -350MPa.

[0139] Performance verification experiment:

[0140] Comparison of heat insulation effects, Table 14:

[0141] trough design Temperature difference ΔT (°C) between adjacent zones Lateral heat flux density (kW / m²) Traditional rectangular groove 8.3 15.6 Equally spaced trapezoidal grooves 5.1 9.8 This embodiment optimizes the slot 1.7 4.2

[0142] Test method: Embed a miniature heat flow sensor (OMEGA HFS-4) at the partition boundary.

[0143] Thermal stress analysis:

[0144] Finite element model table 15 (ANSYS Workbench):

[0145]

[0146] In the formula described above in this embodiment, the arrangement rule of the slots is clearly defined, namely the spacing between the slots: satisfy The coefficients 1.618 (golden ratio φ) and 0.618 (φ-1) are key here, indicating that the spacing of the grooves is not random, but expands in an orderly manner according to mathematical laws related to the golden ratio.

[0147] To execute this rule, two initial values ​​are required. The table shows the specific dimensions chosen for this project:

[0148] The first spacing: d1 is 15.2mm (within the 12-17mm range allowed in the technical solution), and the second spacing: d2 is 24.8mm (within the 23-27mm range allowed in the technical solution). With these two starting points, the subsequent spacings can be automatically calculated using the formula:

[0149] Calculate the third spacing: d3: d3 = 1.618 * d2 - 0.618 * d1 = 1.618 * 24.8 - 0.618 * 15.2 ≈ 40.13 - 9.39 ≈ 30.74 mm.

[0150] Calculate the fourth spacing: d4: d4=1.618*d3-0.618 *d2 =1.618*32.5 -0.618*24.8 ≈52.59-15.33 ≈ 37.26mm.

[0151] In this embodiment, the following measures are taken: the trapezoidal cross section with a 46.5° inclination angle reduces thermal stress by 68%; the Fibonacci sequence arrangement (d1=15.2mm, d2=24.8mm) reduces the transverse heat flux density by 73%; the r=0.35mm rounded corner design completely eliminates the risk of cracking; and the measures work together to solve the problem of temperature uniformity in large-size curved surface components, providing high-precision forming assurance for aerospace, rail transportation and other fields.

[0152] Example 7, the pressure of the hydraulic drive system satisfy:

[0153] ,

[0154] in, The pressure is set to 10-30 MPa, and the pressure fluctuation period is T=10-20 s. Dynamic pressure disturbance is used to suppress the formation of interlayer bubbles.

[0155] In this embodiment, the meaning of each variable is explained in detail, as shown in Table 16:

[0156]

[0157] In this embodiment, the above formula can be understood as: final pressure = reference pressure × (1 + dynamic disturbance);

[0158] The core objective is to suppress the formation of interlayer bubbles.

[0159] The working principle is as follows: a small periodic pressure change is applied at the stage when the resin viscosity is the lowest (usually in the early stage of heating).

[0160] "Squeezing" effect: The half-cycle of increased pressure can more effectively drive the resin flow, fill the tiny gaps between fiber bundles, and "squeeze" out trapped air or volatiles.

[0161] The "shear" effect: Periodic changes in pressure cause micro-vibrations in the fiber web, which apply shear force to the resin. This helps to break the surface tension of the bubbles, making it easier for the small bubbles to merge or dissolve into the resin, thus preventing them from eventually forming defects.

[0162] Technological innovation is embodied in the definition of amplitude A(t) and period T(t) as time variables, which is a key technical feature. This means that the system is not a fixed "vibrator" but an intelligent adaptive system that can dynamically adjust the perturbation parameters based on real-time curing stages (e.g., feedback from temperature or dielectric sensors). For example, a larger amplitude and a specific frequency can be used when the resin viscosity is lowest, while the perturbation can be reduced or stopped after gelation.

[0163] In this embodiment, this adaptive control achieves maximum effect (optimal debubbling) and minimum risk (avoiding excessive disturbance that could lead to fiber misalignment or resin loss). It directly and efficiently achieves the final process goal of suppressing interlayer bubbles through the specific means of adaptive dynamic pressure perturbation.

[0164] Example 8: The distributed thermocouple array is arranged in the following ways: within each independent temperature control area, the thermocouples are arranged in a hexagonal grid with a grid side length of 5-8 mm; the thermocouple probe is embedded to a depth of 1 / 4-1 / 3 of the heating plate thickness, and the distance between the probe tip and the heating element is ≤1 mm.

[0165] In this embodiment, the thermocouple array configuration scheme

[0166] Space Layout Design Table 17:

[0167] parameter Technical Requirements This embodiment implements the value. Technical role Network type Hexagonal tessellation Regular hexagonal unit Maximize coverage without blind spots Grid side length 5-8mm 6.5±0.2mm Balancing measurement density and signal interference Thermocouple density ≥4 pieces / 100cm² 24 pieces / 100cm² Meets the input requirements of multivariate algorithms probe embedding depth Plate thickness 1 / 4-1 / 3 8mm (plate thickness 25mm) Accurately reflects the internal temperature field Tip-HeatingElementDistance ≤1mm 0.8±0.1mm Reduce thermal response hysteresis (<0.5s)

[0168] Advantages of hexagonal grid layout (6.5mm side spacing): 18% reduction in measurement blind zone compared to rectangular grid; temperature gradient direction resolution improved to ±15° (compared to ±30° for traditional grid).

[0169] Key manufacturing process steps in this embodiment

[0170] Heating plate drilling positioning: Laser marking machine marks the vertices of the hexagonal grid (position error ≤ 0.05mm); micro-electro-discharge machining of hole diameter (φ0.6mm, depth 8mm), hole wall roughness Ra≤1.6μm;

[0171] Thermocouple installation: Probe type K armored thermocouple (φ0.5mm, Inconel 600 sheath); high-temperature thermally conductive adhesive filling (Al2O3 based, thermal conductivity ≥25W / m·K) → eliminates air gap thermal resistance; Spacing calibration: X-ray fluoroscopy to check the tip position → ensure a spacing of 0.8±0.1mm with the heating element;

[0172] Temperature field reconstruction and calibration:

[0173] Data fusion algorithm:

[0174] Input: Real-time temperatures T of 24 thermocouples TC (Sampling frequency 10Hz); Infrared thermal imager full-field temperature T IR (Resolution 0.5mm / pixel)

[0175] Reconstruction model:

[0176] ,

[0177] Let the radius be the Gaussian kernel. Weights for infrared data.

[0178] Calibration effect verification table 18:

[0179] Region Type Thermocouple independent measurement error Fusion Reconstruction Error Central uniform region ±0.8℃ ±0.3℃ Edge gradient region ±2.5℃ ±0.7℃ Heating element gap Blind zone > 3mm² No blind spots

[0180] This embodiment achieves blind-zone-free detection through a hexagonal network layout (6.5mm side length); an 8mm embedding depth + 0.8mm near-field distance ensures temperature response adaptability; and a thermocouple-infrared fusion algorithm (λ=0.7) reconstructs the overall temperature, collaboratively solving the problems of local overheating and gradient control in composite material molding, and providing core technical support for the manufacturing of high-precision optical components.

[0181] The above description is only a preferred 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 multi-zone independent temperature control carbon fiber composite hot press forming press, comprising a body frame structure, an electric box (14), a mobile operating platform (15), a liquid filling tank (16) and a hydraulic drive system; the electric box (14) and the mobile operating platform (15) are located on one side of the body frame structure, which comprises an upper cross beam (1), a lower cross beam (2), a movable cross beam (3) and four vertical columns (4) connected by prestressed fixing nuts, and a laser calibration reference surface is arranged on the surface of the vertical column (4); the hydraulic drive system comprises a main cylinder one (5), a main cylinder two (6), a liquid filling valve (7) and a servo motor (8); the main cylinder one (5) and the main cylinder two (6) are respectively connected with the movable cross beam (3) through the main cylinder piston to establish a rigid connection; a hydraulic bolt safety cylinder (9) is arranged between the upper cross beam (1) and the movable cross beam (3), and the liquid filling tank (16) is located on one side of the upper cross beam (1), characterized in that, Also includes a partition heating system, the partition heating system includes the upper heating plate (10) and the lower heating plate (11) are integrated on the movable cross beam (3) and the lower cross beam (2) respectively, the surface of the upper heating plate (10) and the lower heating plate (11) is divided into N independent temperature control areas, each independent temperature control area contains silicon carbide-based embedded heating element, distributed thermocouple array and annular heat insulation groove; In the annular heat insulation groove, nano-porous silica aerogel is filled; The temperature uniformity of each independent temperature control area is realized by multivariable predictive control algorithm; The edge of the lower heating plate (11) is also provided with a safety light curtain (12) composed of infrared emitter and receiver array, which triggers the emergency shutdown of the equipment when detecting foreign matter intrusion into the working area; The mold moving arm (13) is installed on the side of the lower heating plate (11) through the linear guide rail and is driven by the servo motor (8); The multivariable predictive control algorithm satisfies: Wherein, represents the proportional term, represents the integral term, represents the differential term, represents the thermal coupling term, represents the gradient compensation term, is the thermal coupling coefficient of adjacent independent temperature control areas, which is calibrated by offline thermal imager; represents the real-time heating power of the ith independent temperature control area to achieve target temperature control, wherein, K p , K i , K d represent PID parameters; represents the deviation of the target temperature and the actual temperature of the ith independent temperature control area, that is, ΔT i (t)=T target −T i (t), represents the thermal coupling compensation term of adjacent independent temperature control areas; Wherein, T target is the global target temperature, T i (t) is the real-time temperature of the ith independent temperature control area, a ij represents the thermal coupling coefficient of the jth independent temperature control area to the ith independent temperature control area, reflecting the intensity of heat transfer; T j , T i : Respectively represent the real-time temperature of the jth and ith independent temperature control area, represents the second-order temperature gradient compensation term, wherein β represents the compensation factor, which is used to suppress the non-uniform heat dissipation of the edge of each independent temperature control area, The second order derivative of real-time temperature in space represents the curvature of temperature field, is used for reducing the temperature gradient mutation of edge area caused by heat dissipation, is realized by thermocouple array measurement or discrete approximation, and improves the global temperature uniformity; the upper heating plate (10) and the lower heating plate (11) are sandwich composite structures, comprising a bearing layer, a uniform heating layer and a functional layer, the bearing layer is tungsten carbide reinforced copper-based composite material; the uniform heating layer is a directional arrangement of graphene sheet layers, the in-plane thermal conductivity of the graphene sheet layer is greater than or equal to 2000 W / mK, and the vertical carbon nanotube array is grown between the layers by chemical vapor deposition (CVD) method.

2. A multi-zone independently temperature-controlled carbon fiber composite thermoforming press according to claim 1, characterized in that: The guide mechanism of the movable cross beam (3) comprises four sets of double V-shaped roller guide rails, embedded piezoelectric force sensors and a hydraulic servo system, which adjusts the oil cylinder pressure distribution in real time according to the following formula: wherein, represents the real-time output pressure of the kth oil cylinder, with the unit of newton (N); represents the average pressure reference value of all oil cylinders, with the unit of newton (N); R is the equivalent distribution radius of the oil cylinder force, with the unit of meter (m); Δθ is the angle deviation between the actual inclination angle of the movable slot beam and the ideal horizontal plane, with the unit of radian (rad); E is the elastic modulus of the material of the movable cross beam, with the unit of pascal (Pa) or N / m²; I is the cross-sectional moment of inertia of the movable cross beam (3), with the unit of meter 4 (m 4 ), L is the span of the guide rail, with the unit of meter (m); φ k is the azimuth angle of the kth oil cylinder, with the unit of radian (rad) or degree (°), represents the sine value of the azimuth angle of the Kth oil cylinder, with the unit of dimensionless, represents the average value of the sine values of the azimuth angles of the four oil cylinders, with the unit of dimensionless; is the direction correction factor, with the unit of dimensionless.

3. A multi-zone independently temperature-controlled carbon fiber composite thermoforming press according to claim 1, wherein: The functional layer surface is further deposited with TiAlN hard coating by magnetron sputtering for improving the anti-wear and anti-adhesion performance; a transition layer is additionally arranged between the heat-diffusing layer and the functional layer, and the transition layer is a gradient composite structure, which comprises, from bottom to top, a copper-graphene mixed layer and a nanodiamond dispersed layer. The arrangement of the distributed thermocouple array satisfies that, in each independent temperature control area, the thermocouples are arranged in a hexagonal grid.

4. The multi-zone independently temperature-controlled carbon fiber composite thermoforming press of claim 1, wherein: The cross section of the annular heat insulation groove is trapezoidal structure, the groove bottom width is 0.6-0.8 times of the slot width; the groove spacing is arranged according to the modified Fibonacci sequence: d n =1.618d n-1 -0.618d n-2 , the initial spacing: the value range of d1 is 12mm-17mm, the value range of d2 is 23mm-27mm, the groove bottom fillet radius r is greater than or equal to 0.3w, and the groove wall inclination angle θ is 45±2°.

5. A multi-zone independently temperature controlled carbon fiber composite thermoforming press according to claim 1, wherein: The hydraulic drive system applies dynamic pressure perturbation according to the curing process curve, and the pressure satisfies: wherein, Pout represents the real-time output pressure of the hydraulic system, in units of pascal (Pa), Pbase represents the reference pressure setting curve, in units of pascal (Pa), A represents the fluctuation amplitude coefficient of the dynamic pressure, in units of dimensionless, t represents the process time, in units of seconds (s), T represents the fluctuation period of the dynamic pressure, in units of seconds (s), f represents a sinusoidal periodic function, in units of dimensionless, which suppresses the formation of interlayer bubbles through the dynamic pressure.

6. A multi-zone independently temperature controlled carbon fiber composite thermoforming press according to claim 1, wherein: ​

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