Flexible pressure applying hydraulic machine and control method thereof

Abstract

The invention relates to the technical field of hydraulic machines, in particular to a flexible pressure applying hydraulic machine and a control method thereof.The flexible pressure applying hydraulic machine comprises a main cylinder, an auxiliary cylinder, an upper cross beam, a lower cross beam and stand columns and further comprises a multi-stage leveling mechanism and a control system, the multi-stage leveling mechanism comprises four sets of independent electric telescopic ejector rods, a motor system and a plurality of supporting seats, and the electric telescopic ejector rods are arranged in the supporting seats; the supporting seats and the electric telescopic ejector rod are in meshing transmission connection through a motor system driving gear, the height difference between the supporting seats and the electric telescopic ejector rod is dynamically adjusted by the following formula: # imgabs0 #, Pset (unit: MPa) is preset pressure, Pi (unit: MPa) is real-time detection pressure of the ith supporting seat, kp (dimensionless) is a proportional control coefficient, and kd (unit: s-1) is a differential control coefficient; # imgabs1 # represents a derivative operation with respect to time. According to the flexible pressure applying hydraulic machine and the control method thereof, through multi-stage leveling formulation control, SMA flexible driving and an intelligent closed-loop system, the beneficial effect that the precision and safety of the hydraulic machine are remarkably improved is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic presses, and in particular to a flexible pressure hydraulic press and a control method thereof. Background Art

[0002] Currently, traditional hydraulic presses rely on a single drive source for leveling, have a slow response speed, and the rigid pressure force can easily cause damage to the workpiece. They also lack dynamic adjustment control and visual feedback. To address the above-mentioned defects, the present invention provides a flexible pressure hydraulic press and a control method thereof. Through multi-stage leveling formula control, SMA flexible drive and intelligent closed-loop system, the accuracy and safety of products pressed by hydraulic presses are significantly improved. Summary of the Invention

[0003] The purpose of the present invention is to solve the problems existing in the prior art and to propose a flexible pressure hydraulic press and a control method thereof.

[0004] In order to achieve the above-mentioned object, the present invention adopts the following technical solution: a flexible pressure hydraulic press, including a main cylinder, a secondary cylinder, an upper crossbeam, a lower crossbeam, a column, and further comprising: A multi-stage leveling mechanism includes four independent electric telescopic mandrels, a motor system, and multiple support bases. The electric telescopic mandrels are built into the support bases. The support bases and the electric telescopic mandrels are connected by gear meshing transmission driven by the motor system. The height difference between the support bases and the electric telescopic mandrels is dynamically adjusted by the following formula: , where P set (Unit: MPa) is the preset pressure, P i (Unit: MPa) is the real-time detection pressure of the i-th support seat, k p (dimensionless) is the proportional control coefficient, k d (Unit: s -1 ) is the differential control coefficient; represents the derivative operation with respect to time; A flexible pressure component includes an elastic module and a variable direction pressing component. The elastic module has a built-in shape memory alloy (SMA) spring. The driving force of the shape memory alloy (SMA) spring satisfies the following requirements: , where I (unit: A) is the drive current, T (unit: ℃) is the real-time temperature, α (unit: N / A²) is the current response coefficient, β (unit: N / ℃) is the thermal expansion coefficient; T0 is the reference temperature; The above-mentioned directional pressure stripping assembly includes a movable crossbeam, a mold module and an angle sensor. The pressure angle correction amount is calculated by the following formula: , where δ is the workpiece deformation amount on the mold module fed back by the integrated visual recognition module, and L is the length of the mold module contacting the workpiece; It also includes an intelligent control system, a PID regulator and multiple sensors. The intelligent control system forms a closed-loop optimization control and dynamic adjustment for real-time optimizing the pressure application coefficient by integrating the status monitoring of the vision recognition module, the real-time feedback data of multiple sensors, and the precise execution of the PID regulator. The PID regulator outputs a control signal to the multi-level leveling mechanism according to the deviation between the pressure feedback signal P i and the preset pressure P set . It also includes a buffer module. The buffer module contains three-level elastic deformation grooves and slope transmission components. The impact absorption efficiency of the buffer module is calculated as: , where k n (unit: N / m) is the stiffness coefficient of the nth-level elastic deformation groove, x n (unit: m) is the deformation amount of the nth-level elastic deformation groove, and d (unit: m) is the impact displacement; represents the impact force (unit: N), which is the magnitude of the external impact force applied to the buffer module; A force analysis and leveling module. The force analysis and leveling module contains multi-axis pressure sensors distributed on the tops of each support seat for real-time collecting the three-dimensional force data F x,i , F y,i , F z,i (unit: N) of the support points of the support seat. The intelligent control system dynamically corrects the height difference of the support seat according to the three-dimensional force data of the support points and the pressure feedback through the following formula: , where is the corrected height adjustment amount of the ith support seat; Δh i is the original height adjustment amount of the ith support seat, r is the force distribution correction coefficient, F z,i is the vertical force of the ith support point, is the average vertical force.

[0005] Furthermore, the mold module includes an upper mold backing plate and a lower mold backing plate. A workpiece to be pressed is placed above the lower mold backing plate. The shape memory alloy (SMA) spring is sleeved on the lower part of the guide post of the upper mold backing plate. The upper end and the lower end of the shape memory alloy (SMA) spring are respectively connected to the movable crossbeam and the upper mold backing plate. The upper mold backing plate is connected to the movable crossbeam through the guide post of the upper mold backing plate, and the top of the guide post of the upper mold backing plate is connected to the movable crossbeam through a lock nut of the guide post of the upper mold backing plate.

[0006] Further, a three - stage elastic deformation groove is provided between the shape memory alloy (SMA) spring and the guide pillar of the upper die backing plate. The three - stage elastic deformation groove is composed of a polyurethane layer, a silica gel layer, and a disc spring stacked in sequence, and the elastic coefficient ratio of each layer is 1:2.5:4. The three - stage elastic deformation groove is embedded and coupled with the slope transmission member. The bottom of the slope transmission member contacts the first - stage elastic deformation groove of the three - stage elastic deformation groove. The middle part of the slope transmission member contacts the second - stage elastic deformation groove of the three - stage elastic deformation groove through a guide groove. The top of the slope transmission member is rigidly fixed to the third - stage elastic deformation groove of the three - stage elastic deformation groove.

[0007] Further, the PID parameters of the intelligent control system are optimized online through the following formula: , where K p0 and K i0 are the reference values of the PID parameters, determined by offline calibration, λ is the attenuation factor (unit: s -1 ), configured according to the system response time; γ is the pressure correction coefficient (unit: Pa -1 ), satisfying; ; ΔP is the deviation between the set pressure (P set ) and the actual instantaneous pressure (P i ) (ΔP = P set - P i , unit: Pa).

[0008] Further, the integrated vision recognition module uses a convolutional neural network (CNN) to extract the workpiece deformation characteristics, and the output resolution ≤ 0.05 mm; the surface of the support seat is provided with a wear - resistant ceramic coating, and the friction coefficient ≤ 0.15.

[0009] A control method for using the flexible pressure - applying hydraulic press described in any one of the above, including the following steps: S1. Obtain the workpiece deformation characteristics through the vision system of the integrated vision recognition module, and calculate the workpiece deformation amount δ; S2. Adjust the pressure - applying angle based on the formula Δθ = arctan(δ / L); S3. Optimize the PID parameters in real - time according to the pressure feedback, and drive the multi - stage leveling mechanism to dynamically level.

[0010] Further, the intelligent control system is built - in with a dynamic load - balancing algorithm, and calculates the moment balance deviation of each support point through the following formula: , where, 、 are the reaction forces of the i - th support point in the x and y directions (unit: Newton, N), x i 、y iis the planar coordinate of the i-th support point (unit: m), M dev is the comprehensive moment balance deviation (unit: N·m); when M dev >M set it triggers the secondary correction of the multi-level leveling mechanism, and the moment balance deviation threshold M set is determined by the yield strength σ y of the workpiece material and the contact area A: , where L is the length of the die module in contact with the workpiece (unit: m).

[0011] Furthermore, the force analysis leveling module is data-fused with the integrated vision recognition module, and the equivalent deformation compensation amount δ of the workpiece is calculated by the following formula eq： , where δ is the deformation amount of the workpiece detected by the vision system (unit: meter); is the vertical force on the i-th support point (unit: Newton); α and β are weight coefficients, satisfying α + β = 1; L1 is the characteristic length of the workpiece (unit: meter); the equivalent deformation compensation amount δ eq is converted into the pressing angle correction amount Δθ through the proportional coefficient k to drive the secondary adjustment of the flexible pressing component.

[0012] Furthermore, in the overload protection stage, the intelligent control system automatically selects the priority locking points according to the force distribution, and the locking order is determined by the following criterion: , where α and β are weight coefficients, satisfying α + β = 1, and satisfying the condition: , where F x,i is the real-time load of the i-th support point; is the local stress at the i-th support point; represents the effective bearing area of the i-th support point (unit: m²); σ y is the material yield degree; is the maximum allowable load for a single support point.

[0013] Compared with the existing technology, the advantages of the present invention are as follows: A flexible pressing hydraulic press and its control method proposed by the present invention have achieved the beneficial effects of significantly improving the accuracy and safety of the hydraulic press through multi-level leveling formula control, SMA flexible drive, and intelligent closed-loop system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a cross-sectional view of the flexible pressing hydraulic press in the present invention; Figure 2 is a front view of the flexible pressing hydraulic press in the present invention; In the figure: 2 - upper die backing plate; 3 - guide pillar of upper die backing plate; 4 - lock nut of guide pillar of upper die backing plate; 5 - shape memory alloy (SMA) spring; 6 - lower die backing plate; 7 - lower crossbeam; 8 - movable crossbeam; 10 - main cylinder; 11 - auxiliary cylinder; 12 - column; 13 - support seat; 14 - motor system; 15 - electric telescopic ejector rod. Specific embodiments

[0015] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0016] Example 1, please refer to the Figure 1 - Figure 2 accompanying drawings of the specification. A flexible pressure - applying hydraulic press includes a main cylinder 10, an auxiliary cylinder 11, an upper crossbeam, a lower crossbeam 7, and columns 12. In this embodiment, the main cylinder 10 provides the main pressure output, and the auxiliary cylinder 11 assists in balancing the off - load during the pressure - applying process. The upper crossbeam and the lower crossbeam are connected by columns 12 to form a frame body. It further includes: A multi - level leveling mechanism, including four groups of independent electric telescopic ejector rods 15, a motor system 14, and multiple support seats 13. The electric telescopic ejector rods 15 are built into the support seats 13. The support seats 13 and the electric telescopic ejector rods 15 are driven by the motor system 14 through gear meshing transmission connections to adjust the height of each support seat 13 in real time. The frame body is used to support the multi - level leveling mechanism. The height difference between the support seats 13 and the electric telescopic ejector rods 15 is dynamically adjusted by the following formula: , where P set (unit: MPa) is the preset pressure, P i (unit: MPa) is the real - time detected pressure of the i - th support seat 13, k p (dimensionless) is the proportional control coefficient, k d (unit: s -1 ) is the differential control coefficient; represents the derivative operation with respect to time; A flexible pressure - applying component, including an elastic module and a variable - direction pressing component. The elastic module incorporates a shape memory alloy (SMA) spring 5, and its driving force satisfies: , where I (unit: A) is the driving current, T (unit: °C) is the real - time temperature, α (unit: N / A²) is the current response coefficient, β (unit: N / °C) is the thermal expansion coefficient; T0 is the reference temperature; The variable - direction pressing component includes a movable crossbeam 8, a die module, and an angle sensor. The pressure - applying angle correction amount is calculated by the following formula: , where δ is the workpiece deformation amount on the mold feedback by the integrated vision recognition module, and L is the length of the mold module in contact with the workpiece; It also includes an intelligent control system, a PID regulator and multiple sensors. The intelligent control system forms a closed-loop optimization control and dynamic adjustment through the status monitoring of the integrated vision recognition module, the real-time feedback data of the multiple sensors, and the precise execution of the PID regulator, and is used to optimize the pressure application coefficient in real time; the PID regulator outputs a control signal to the multi-level leveling mechanism according to the deviation between the pressure feedback signal P i and the preset value P set ; The buffer module includes three-level elastic deformation grooves and a slope transmission member, and its shock absorption efficiency is calculated as: , where k n (unit: N / m) is the stiffness coefficient of the nth-level elastic deformation groove, x n (unit: m) is the deformation amount of the nth-level elastic deformation groove, and d (unit: m) is the impact displacement; The force analysis and leveling module includes multi-axis pressure sensors distributed on the tops of the support seats 13, and is used to collect the three-dimensional force data F x,i , F y,i , F z,i (unit: N) of the support points of the support seat 13 in real time; the intelligent control system dynamically corrects the height difference of the support seat 13 according to the force data of the support points and the pressure feedback through the following formula: , where Δh i is the original height adjustment amount of the ith support seat 13, is the force distribution correction coefficient, F z,i is the vertical force of the ith support point, is the average vertical force. On the basis of the above embodiments, the height difference between the support seat 13 of the multi-level leveling mechanism and the electric telescopic jack 15 is dynamically adjusted.

[0017] In the formula: , Combined with the parameter embodiments: set K P = 0.8 (dimensionless); K d = 0.05s -1 , P set = 20 MPa, the real-time detection pressure of the ith support seat 13, P i range: 18 MPa ≤ p i ≤ 22 MPa, The calculation steps are as follows: Assume the real-time pressure and change rate at a certain moment: Take P i= 19 MPa (pressure is lower than the preset pressure) Assume that the rate of change of the pressure deviation value with time is The negative sign indicates that the pressure difference is decreasing, i.e., P i approaches P set ; Substitute into the formula for calculation: , Result analysis: Contribution of the proportional term: 0.8×(20 - 19) = 0.8 mm, dominating the leveling action; Contribution of the differential term: 0.05×(-0.1) = -0.005 mm, slightly suppressing overshoot; Total adjustment amount: 0.795 mm, indicating that the support point needs to be raised by approximately 0.8 mm at this time to compensate for the pressure deviation; According to P i range (18 MPa to 22 MPa), assume that the differential term can be ignored (at steady state, ), When P i = 18 MPa: , When P i = 22 MPa: , Conclusion: Δh i is the original height adjustment amount of the i-th support seat 13, and the range is approximately -1.6 mm ≤ Δh i ≤ 1.6 mm; the differential term can suppress oscillations during the dynamic process, but the original height adjustment amount of the i-th support seat 13 at steady state is mainly determined by the proportional term.

[0018] Based on the above embodiments, the driving force formula of the shape memory alloy (SMA) spring 5: , Set parameter examples as follows: Current response coefficient α = 2.5 N / A 2 (made of nickel-titanium alloy), Thermal expansion coefficient β = 0.03 N / ℃, Reference temperature T0 = 25℃, Driving current I = 3 A (peak current in pulse mode), Real-time temperature T = 30℃ (working environment temperature rise); Calculation example: ; Set parameter examples as follows: Workpiece deformation amount δ = 0.5 (detected value by the vision system), Length L of the mold module in contact with the workpiece = 200 mm (rectangular workpiece), Calculation example: 。

[0019] In this embodiment, the formula for the shock absorption efficiency of the buffer module is: , The parameters are set as follows: The stiffness coefficient of the first-stage elastic deformation groove: k1 = 1×10 6 N / m (polyurethane layer), The stiffness coefficient of the second-stage elastic deformation groove: k2 = 2.5×10 6 N / m (silicone layer), The stiffness coefficient of the third-stage elastic deformation groove: k3 = 4×10 6 N / m (butterfly spring), The deformation amount x1 of the first-stage elastic deformation groove = 0.002m, The deformation amount x2 of the second-stage elastic deformation groove = 0.0015m, The deformation amount x3 of the third-stage elastic deformation groove = 0.001m, The impact force F impack = 5000N, The impact displacement d = 0.005m; Calculation example: 。

[0020] In this embodiment, the formula for dynamically correcting the height difference of the support base 13 is as follows: , The parameters are set as follows: The original height adjustment amount of the i-th support base 13: Δℎ i = 0.1 mm, The force distribution correction coefficient r = 0.3 (empirical value, which needs to be adjusted according to the stiffness of the support base 13), The average vertical force , The vertical force F at the i-th support point z,i = 1400N; Calculation example: Δh i ′ = 0.1 + 0.3×(1500 - 1400) = 0.1 + 30 = 30.1mm.

[0021] The above parameters need to be adjusted according to the actual materials, working conditions and experimental data, and can be further optimized through finite element simulation or original model testing.

[0022] Example 2. On the basis of the above Example 1, the specific structure and implementation method of the mold module are further refined. The mold module includes an upper mold backing plate 2 and a lower mold backing plate 6. A workpiece to be pressed is placed above the lower mold backing plate 6. The shape memory alloy (SMA) spring 5 is sleeved on the lower part of the guide post 3 of the upper mold backing plate. The upper end of the shape memory alloy (SMA) spring 5 is fixed to the movable crossbeam 8, and the lower end is connected to the upper mold backing plate 2. The driving method: by adjusting the contraction amount of the shape memory alloy (SMA) spring 5 through current, flexible control of the pressing force is achieved (the formula remains F SMA =α×I 2 +β×(T - T0)); The upper mold backing plate 2 is connected to the movable crossbeam 8 through the guide post 3 of the upper mold backing plate and can move vertically along the guide post. The top of the guide post 3 of the upper mold backing plate is connected to the movable crossbeam 8 through the lock nut 4 of the guide post of the upper mold backing plate.

[0023] In this embodiment, the implementation steps of the pressing process are as follows: 1. Workpiece installation: Place the workpiece on the lower mold backing plate 6 and position it through a fixture; Select a suitable upper mold backing plate 2 and end sub - mold (if required) according to the workpiece size 2. Pre - loading of the shape memory alloy (SMA) spring 5: Set the initial current I0 = 2A to drive the shape memory alloy (SMA) spring 5 to generate a pre - tightening force F pre =α×I0 2 =2.5×2 2 =10N to eliminate the assembly gap; Real - time monitor the real - time temperature T. If the ambient temperature deviates from the reference temperature T0 = 25°C, correct the driving force through the thermal compensation algorithm; 3. Dynamic pressing and leveling: The main cylinder 10 drives the movable crossbeam 8 to press down. The shape memory alloy (SMA) spring 5 adjusts the driving current I in real - time according to the pressure feedback to achieve non - linear output of the pressing force; The vision system detects the deformation amount δ of the workpiece, calculates the pressing angle correction amount Δθ = arctan(δ / L), and dynamically adjusts the inclination angle of the movable crossbeam 8.

[0024] 4. Safety and reset: After the pressing is completed, cut off the current of the shape memory alloy (SMA) spring 5, and the shape memory alloy (SMA) spring 5 returns to its initial length.

[0025] If overload is detected (P i >22MPa or δ>1mm), trigger the mechanical limit lock to lock the guide post 3 of the upper mold backing plate to prevent damage to the mold module.

[0026] In this embodiment, the achieved technical effects are as follows: Flexible pressure application accuracy: The current-force response accuracy of the shape memory alloy (SMA) spring 5 reaches ±1.5%, and the uniformity of the workpiece force is improved by ≥25%; Die life: The upper die backing plate guide post lock nut 4 and the low-friction design reduce the wear rate of the die module by 40%; Quick die change: The standardized interface design (such as dovetail groove) enables the die change time to be ≤30 seconds; Anti-eccentric load capacity: The multi-level leveling mechanism and the shape memory alloy (SMA) spring 5 work together to compensate for the initial installation tilt error of ±2°.

[0027] Table 1 gives examples of key parameters: Component Parameter Name Typical Value / Range Shape Memory Alloy (SMA) Spring 5 Drive Current I 2A ≤ I ≤ 5A Upper Die Pad Guide Post 3 Surface Hardness HRC 60 - 62 (Hardening Treatment) Upper Die Pad / Lower Die Pad (2 / 6) Flatness of Contact Surface ≤10 μm Lock Nut of Upper Die Pad Guide Post 4 Pre - tightening Torque In this embodiment, the specific parameters in Table 1 should be calibrated through experiments according to the actual working conditions.

[0028] Embodiment 3, a three-stage elastic deformation groove is provided between the shape memory alloy (SMA) spring 5 and the upper die backing plate guide post 3. The three-stage elastic deformation groove is composed of a polyurethane layer, a silica gel layer, and a disc spring stacked in sequence, and the elastic coefficient ratio of each layer is 1:2.5:4; The three-stage elastic deformation groove is embedded and coupled with the slope transmission member, and the bottom of the slope transmission member contacts the first-stage groove of the three-stage elastic deformation groove; The middle part of the slope transmission member contacts the second-stage groove of the three-stage elastic deformation groove through a guide groove; The top of the slope transmission member is rigidly fixed to the third-stage groove of the three-stage elastic deformation groove.

[0029] In the above embodiment, the hierarchical composition of the three-stage elastic deformation groove: The first-stage elastic deformation groove: It is composed of a polyurethane layer, with a stiffness coefficient k1 = 1×10 6 N / m and a thickness t1 = 10 mm, which is used to absorb the initial impact energy, The second-stage elastic deformation groove: It is composed of a silica gel layer, with a stiffness coefficient k2 = 2.5×10 6 N / m and a thickness t2 = 8 mm, which bears medium-strength impacts, The third-stage elastic deformation groove: It is composed of a disc spring, with a stiffness coefficient k3 = 4×10 6 N / m and a thickness t3 = 5 mm, which is used to absorb the residual impact load, The elastic coefficient ratio of each layer strictly satisfies k1:k2:k3 = 1:2.5:4 to ensure staged energy absorption, In this embodiment, the three-stage elastic deformation groove is embedded between the shape memory alloy (SMA) spring 5 and the upper die backing plate guide post 3 and is fixed through an embedded snap structure.

[0030] In this embodiment, the connection mode between the slope transmission member and the three-stage elastic deformation groove is as follows: the bottom inclined surface of the slope transmission member is in direct contact with the polyurethane layer of the first-stage elastic deformation groove, and the initial impact force is decomposed into a horizontal component force and a vertical component force through the slope; a guiding groove is provided in the middle of the slope transmission member, and is slidably connected with the silica gel layer of the second-stage elastic deformation groove through a slider to ensure that the impact force is transmitted along a preset path. The top of the slope transmission member is rigidly connected to the disc spring of the third-stage elastic deformation groove through bolts to transmit the residual impact load. The slope angle is designed as: the slope inclination angle θ = 30°, optimizing the decomposition ratio of the impact force. The calculation formula is: F horizontal =F impact ×sinθ, F vertical =F impact ×cosθ. The horizontal component force is absorbed by the three-stage elastic deformation groove, and the vertical component force is transmitted to the upper die backing plate 2 and the lower die backing plate 6 through the guide post 3 of the upper die backing plate.

[0031] The technical implementation steps are as follows: Impact load transmission process: When applying pressure, assume that the impact force F impact = 8000N of the main cylinder 10 is transmitted to the slope transmission member through the moving crossbeam 8; The first-stage elastic deformation groove absorbs the initial impact force, and the deformation amount x1 of the polyurethane layer = 0.003m; The first-stage elastic deformation groove further buffers, and the deformation amount x2 of the silica gel layer = 0.002m; The first-stage elastic deformation groove absorbs the residual energy through the compression of the disc spring, and the deformation amount x3 = 0.001m.

[0032] Energy absorption efficiency calculation: Substitute into the buffer module formula: , The impact displacement d = x1 + x2 + x3 = 0.006m, Calculated: .

[0033] The measured efficiency can reach ≥60% (due to the incomplete inclusion of the non-linear characteristics of the material in the formula). In this embodiment, the achieved technical effects are as follows: Buffering performance: The collaborative design of the three-stage elastic deformation groove and the slope transmission member improves the impact absorption efficiency to ≥60%, a 25% increase compared to the single-stage buffer structure; Structural life: The staged load transmission reduces the peak stress, and the fatigue life of key components (such as the guide post 3 of the upper die backing plate and the die module) is extended by 40%; Dynamic stability: The design of the guiding groove and the slider ensures that the impact force path is controllable, avoiding die offset caused by eccentric loading; Maintenance convenience: The embedded snap structure supports the quick replacement of worn polyurethane or silicone layers, and the maintenance time ≤ 15 minutes.

[0034] Examples of the key parameters of the elastic deformation groove in this embodiment are shown in Table 2 as follows: Component Parameter Name Typical Value / Range First - stage Elastic Deformation Groove Stiffness Coefficient k1 of the First - stage Elastic Deformation Groove <![CDATA[1×10 6 N / m]]> Second - stage Elastic Deformation Groove Is the Stiffness Coefficient k2 of the Second - stage Elastic Deformation Groove <![CDATA[2.5×10 6 N / m]]> Third - stage Elastic Deformation Groove <![CDATA[Stiffness coefficient k3 of the third-level elastic deformation groove]]> <![CDATA[4×10 6 N / m <!-- 8 -->]]> Slope Transmission Component Slope Angle θ 30° Three - stage Elastic Deformation Groove Impact Displacement d 0.006m 。

[0035] Example 4, on the basis of the above embodiment, the PID parameters of the intelligent control system are optimized online through the following formula: , where K p0 and K i0 are the reference values of the PID parameters, determined by offline calibration, λ is the attenuation factor (unit: s -1 ), configured according to the system response time; γ is the pressure correction coefficient (unit: Pa -1 ), satisfying ; ΔP is the deviation between the set pressure (P set ) and the actual instantaneous pressure (P i ) (ΔP = P set - P actual , unit: Pa).

[0036] The specific implementation steps in this embodiment are as follows: Step 1: Benchmark parameter calibration Under no-load conditions, determine the initial PID parameters through a step response test: K p0 = 1.2 (proportional reference value), K i0 = 0.05 s -1 (integral reference value), Calibrate λ and γ: λ = 0.1 s -1 (system response time t response = 10 s), γ = 2×10 -5 Pa -1 (ensure |γ·ΔP| < 0.5); Step 2: Real-time parameter adjustment Dynamically adjust the proportional gain parameter K p : Decay over time to suppress overshoot. For example, when t = 5 s, , Integral reference value K i : Dynamically adjust according to the pressure deviation. For example, when ΔP = 2×10 4 Pa, ; Step 3: Closed-loop control verification When pressing an aluminum alloy workpiece (P set = 20 MPa): Initial stage (t < 2 s): K p is relatively large (≈1.2), quickly responding to pressure deviation; Steady state stage (t > 5 s): K p decays to 0.728 to avoid oscillation; When the actual pressure P actual = 18 MPa (ΔP = 2 MPa), K i increases to 0.07 s -1 to accelerate the elimination of the steady state error.

[0037] In this embodiment, the achieved technical effects are as follows: Dynamic response optimization: The decay of the dynamically adjusted proportional gain parameter reduces the overshoot by ≥ 30%, and the dynamic adjustment of the integral reference value makes the steady state error ≤ 0.5 MPa; Enhanced adaptability: The pressure correction coefficient γ ensures that the integral reference value is within a safe range (|γ·ΔP| < 0.5) to avoid integral saturation; Table 3 is a diagram of the dynamic adjustment of the integral reference value, and the measured data for adjusting the steady state error are as follows: Operating Condition Overshoot of Traditional PID Overshoot of This Scheme Steady - state Error (MPa) Sudden Load (20 MPa) 15% 5% ≤0.3 Step Disturbance (±2 MPa) Sustained Oscillation Fast Convergence ≤0.5 ; Table 4 is an example diagram of the parameters in the adjustment process in this embodiment as follows: Parameter Symbol Typical Value / Range Function Description Proportional Reference Value <![CDATA[K p0 > <![CDATA[1.0 ≤ K p0 ≤ 1.5]]> Initial Fast Response Integral Reference Value <![CDATA[K i0 > <![CDATA[0.03 ≤ K i0 ≤ 0.08 s -1 > Steady - state Accuracy Adjustment Decay Factor λ <![CDATA[0.05≤λ≤0.2s -1 > Suppress Overshoot and Match System Inertia Pressure Correction Coefficient γ <![CDATA[1×10 -5 ≤γ≤5×10 -5 Pa -1 > Prevent Integral Term Overload ; In this embodiment, parameter fine-tuning needs to be combined with the actual dynamic characteristics of the system. It is recommended to further optimize λ and γ through real-time data acquisition and adaptive algorithms (such as fuzzy logic).

[0038] Example 5, based on the above embodiment, the integrated vision recognition module uses a convolutional neural network (CNN) to extract the workpiece deformation characteristics, and the output resolution ≤ 0.05 mm; the surface of the support base 13 is provided with a wear-resistant ceramic coating, and the friction coefficient ≤ 0.15.

[0039] Example 6, a control method using any one of the above flexible pressing hydraulic presses, includes the following steps: S1. Obtain the workpiece deformation characteristics through the vision system of the integrated vision recognition module, and calculate the deformation amount δ; S2. Adjust the pressing angle based on the formula Δθ = arctan(δ / L); S3. Optimize the PID parameters in real time according to the pressure feedback, and drive the multi-level leveling mechanism for dynamic leveling.

[0040] Example 7. On the basis of the above Example 1, the intelligent control system is built-in with a dynamic load balancing algorithm, and the moment balance deviation of each support point is calculated by the following formula: , where, 、 are the reaction forces of the i-th support point in the x and y directions (unit: Newton, N), xi and yi are the plane coordinates of the i-th support point (unit: meter, m), and M dev is the comprehensive moment balance deviation (unit: Newton-meter, N·m); When M dev > M set , trigger the secondary correction of the leveling mechanism. The moment balance deviation threshold M set is determined by the yield strength σ y of the workpiece material and the contact area A: M set = 0.2 • δ y • A • L, where L is the maximum span of the workpiece (unit: meter, m).

[0041] In this embodiment, the implementation steps of the dynamic load balancing algorithm are as follows: Step 1: Data acquisition: Collect data in real time through the multi-axis pressure sensors on each support base 13: F xi 、F yi : The reaction forces of the i-th support point in the x and y directions (unit: N), x i 、y i : The plane coordinates of the i-th support point (unit: m), calibrated based on a preset coordinate system; Step 2: Calculation of moment balance deviation: Calculate the comprehensive moment balance deviation M dev according to the formula: , In this embodiment, Table 5 is a data reference table for four support points: Support Point <![CDATA[F xi (N)]]> <![CDATA[F yi (N)]]> <![CDATA[x i (m)]]> <![CDATA[y i (m)]]> 1 500 300 0.2 0.2 2 -450 280 -0.2 0.2 3 -480 -320 -0.2 -0.2 4 520 -290 0.2 -0.2 , Calculated: .

[0042] Example 8. On the basis of the above embodiment, the force analysis leveling module and the integrated vision recognition module are data-fused, and the equivalent deformation compensation amount δ eq of the workpiece is calculated by the following formula: , where δ is the deformation amount detected by the vision system (unit: meter); is the vertical force on the i-th support point (unit: Newton); α and β are weight coefficients, satisfying α + β = 1; L is the characteristic length of the workpiece (unit: meter); the equivalent deformation compensation amount δ eq is converted into the pressing angle correction amount Δθ through the proportional coefficient k to drive the secondary adjustment of the pressing mechanism.

[0043] In this embodiment, the secondary adjustment of the flexible pressing component is converted into the pressing angle correction amount through the proportional coefficient. The force analysis leveling module and the integrated vision recognition module perform data fusion, and the equivalent deformation compensation amount of the workpiece is calculated through the following formula. The steps of the embodiment are as follows: 1. Data acquisition and preprocessing: Visual deformation amount detection: Obtain the surface topography of the workpiece through a high-resolution industrial camera or a laser scanner, and calculate the real-time deformation amount δ (unit: meter) using an image processing algorithm (such as digital image correlation method) Vertical force measurement: Install multi-axis pressure sensors at each support point of the hydraulic press (such as the four support seats of a four-column hydraulic press) to monitor the vertical force on the i-th support point in real time (unit: Newton); 2. Equivalent deformation compensation amount: Calculate the equivalent deformation compensation amount of the workpiece according to the formula of the above embodiment: In this embodiment, the parameters are set as follows: α = 0.3, β = 0.7, L = 0.2m, δ = 0.001m (1 millimeter), , , k = 0.5 rad / m.

[0044] Calculation steps: 1. Equivalent deformation compensation amount: , Calculate the first item: , The fractional part of the second item: , The whole of the second item: , Then , 2. Pressing angle correction amount Δθ: Δθ = arctan(δ / L) = 0.5 x 0.0353 = 0.01765rad ~ 1.01°.

[0045] In this embodiment, this formula is an empirical calculation formula derived from the above geometric formula of Δθ = arctan(δ / L), where δ = 0.0353 m (deformation compensation amount) and L = 2 m (reference distance), and the above result is calculated. For example, to verify the geometric formula: , under the current parameters, the results of the two formulas are the same, but it should be noted that: Limitations of the empirical formula: If L or δ changes greatly, the empirical coefficient 0.5 may fail; Universality of the geometric formula: No matter how L changes, the formula can automatically adapt.

[0046] Result analysis: Due to the flexibility of the material (β = 0.7), the compensation amount is mainly contributed by the force distribution difference (35 mm); The angle correction is about 1 degree, and it is necessary to verify whether the robotic arm supports this adjustment accuracy.

[0047] Verification of extreme cases: 1. The deformation amount completely dependent on the vision system detection (α = 1, β = 0): , If ; 2. Completely dependent on the force distribution (α = 0, β = 1): , If L = 0.5 m, , , Then: .

[0048] Table 6 is a parameter example table in this embodiment, as follows: Parameter Symbol Reasonable Range Application Scenario Example Weight Coefficient α [0, 1] Rigid Material: 0.8, Flexible Material: 0.3 Weight Coefficient β [0, 1 (satisfying α + β = 1) Rigid Material: 0.2, Flexible Material: 0.7 Characteristic Length L [0.1 m, 2.0 m] Small Workpiece: 0.1 m, Large Structural Component: 2.0 m Deformation Quantity Detected by Vision System δ <![CDATA[[1×10 -6 m, 5×10 -3 m]]]> <![CDATA[Precision machining: 1×10 -6 m, general machining: 1×10 -3 m]]> Vertical Force <![CDATA[F z,i > [5,000N, 500,000 N] Small Hydraulic Press: 50 kN, Large Hydraulic Press: 500 kN Proportional Coefficient k [0.1rad / m,1.0 rad / m] Short - arm Machine: 1.0 rad / m, Long - arm Machine: 0.1 rad / m , In this embodiment, the parameters in the formula need to be selected within a reasonable range according to the specific application scenario and verified for their effectiveness through actual tests.

[0049] Embodiment 9, based on the above Embodiment 1, in the overload protection stage, the intelligent control system automatically selects the priority locking points according to the force distribution, and the locking order is determined by the following criteria: , where α and β are weight coefficients, satisfying α + β = 1, and satisfying the conditions: , where F x,i is the real-time load of the i-th support point; σ i is the local stress at the i-th support point; A i represents the effective bearing area of the i-th support point (unit: square meter, m²); σ y is the material yield strength; The maximum load allowed for a single support point.

[0050] In this embodiment, the specific implementation method is as follows: 1. Data acquisition and preprocessing: Real-time load monitoring: Install multi-axis pressure sensors at each support point of the hydraulic press (such as the four support seats of a four-column hydraulic press) to monitor the vertical load Fi of the ith support point in real time x,i (unit: Newton, N); Local stress calculation: Through the formula Calculate the local stress σ at the ith support point i (unit: Pascal, Pa), where A i Is the effective bearing area of the ith support point (unit: square meter, m²); Material parameter input: Set the material yield strength σ y (unit: Pa) and the maximum load F allowed for a single support point max-allowed (unit: N); 2. Locking priority calculation: Calculate the locking priority of each support point according to the following formula: , Set the following parameters: α = 0.6, β = 0.4, F max-allowed = 100,000 N, σ y = 250 MPa = 250×10 6 Pa, Data of support point one: , Data of support point two: .

[0051] Calculation steps: 1. Locking priority of support point one: , 2. Locking priority of support point two: , In this embodiment, the priority of support point two (0.667) is higher than that of support point one (0.547), and support point two is locked first; if the preset threshold is 0.6, support point two triggers locking and support point one does not trigger.

[0052] In this embodiment, the achieved technical effects are as follows: Dynamic risk assessment: Comprehensive load and stress dual indicators are used to accurately identify high-risk support points; Adjustable weight: Adapt to different working conditions through α and β (increase the weight of β in heavy-load scenarios); Quick response: Calculate priorities based on real-time data to ensure the timeliness of overload protection, In this embodiment, by fusing load and stress data, intelligent decision-making in the overload protection stage of the hydraulic press is achieved, effectively improving the safety and reliability of the equipment. The parameters in the formula need to be calibrated according to the specific equipment and material characteristics and dynamically optimized in combination with the actual working conditions.

[0053] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A flexible pressure hydraulic press, comprising a main cylinder (10), an auxiliary cylinder (11), an upper crossbeam, a lower crossbeam (7), and columns (12), characterized in that, It further includes: Multi-level leveling mechanism, which includes four groups of independent electric telescopic jacks (15), a motor system (14) and multiple support seats (13). The electric telescopic jacks (15) are built into the support seats (13), and the support seats (13) and the electric telescopic jacks (15) are driven and connected by gear meshing through the motor system (14). The height difference between the support seats (13) and the electric telescopic jacks (15) is dynamically adjusted by the following formula: , where P set (unit: MPa) is the preset pressure, P i (unit: MPa) is the real-time detected pressure of the i-th support seat (13), k p (dimensionless) is the proportional control coefficient, k d (unit: s -1 ) is the derivative control coefficient; represents the derivative operation with respect to time; Flexible pressure application assembly, in which an elastic module and a deflection pressure holding assembly are included. The elastic module internally has a shape memory alloy (SMA) spring (5), and the driving force of the shape memory alloy (SMA) spring (5) satisfies: , where I (unit: A) is the driving current, T (unit: °C) is the real-time temperature, α (unit: N / A²) is the current response coefficient, β (unit: N / °C) is the thermal expansion coefficient; T0 is the reference temperature; The variable-direction pressing component includes a movable crossbeam (8), a die module, and an angle sensor. The pressing angle correction amount is calculated by the following formula: , where δ is the workpiece deformation amount on the die module feedback by the integrated vision recognition module, and L is the length of the die module in contact with the workpiece; It also includes an intelligent control system, a PID regulator and multiple sensors. The intelligent control system forms a closed-loop optimization control and dynamic adjustment for real-time optimizing the pressure application coefficient by integrating the status monitoring of the vision recognition module, the real-time feedback data of the multiple sensors and the precise execution of the PID regulator. The PID regulator outputs a control signal to the multi-level leveling mechanism according to the deviation between the pressure feedback signal P i and the preset pressure P set ; It further includes a buffer module, which contains three-level elastic deformation grooves and a slope transmission component. The impact absorption efficiency of the buffer module is calculated as follows: , where k n (unit: N / m) is the stiffness coefficient of the nth-level elastic deformation groove, and x n (unit: m) is the deformation amount of the nth-level elastic deformation groove, and d (unit: m) is the impact displacement; represents the impact force (unit: N), which is the magnitude of the external impact force applied to the buffer module; A force analysis and leveling module, in which multi-axis pressure sensors are distributed on the tops of the support seats (13) for real-time acquisition of three-dimensional force data F at the support points of the support seats (13). x,i , F y,i , F z,i (unit: N); The intelligent control system dynamically corrects the height difference of the support seats (13) according to the three-dimensional force data and pressure feedback at the support points through the following formula: , where is the corrected height adjustment amount of the i-th support seat (13); Δh i is the original height adjustment amount of the i support seats (13), r is the force distribution correction coefficient, F z,i is the vertical force at the i-th support point, is the average vertical force.

2. The flexible pressure hydraulic press according to claim 1, characterized in that, The mold module includes an upper mold backing plate (2) and a lower mold backing plate (6). A workpiece to be pressed is placed above the lower mold backing plate (6). The shape memory alloy (SMA) spring (5) is sleeved on the lower part of the upper mold backing plate guide post (3). The upper and lower ends of the shape memory alloy (SMA) spring (5) are respectively connected to the movable crossbeam (8) and the upper mold backing plate (2). The upper mold backing plate (2) is connected to the movable crossbeam (8) through the upper mold backing plate guide post (3), and the top of the upper mold backing plate guide post (3) is connected to the movable crossbeam (8) through the upper mold backing plate guide post lock nut (4).

3. A flexible pressure hydraulic press according to claim 2, characterized in that, A three - stage elastic deformation groove is arranged between the shape memory alloy (SMA) spring (5) and the upper mold backing plate guide post (3). The three - stage elastic deformation groove is composed of a polyurethane layer, a silica gel layer and a disc spring stacked in sequence, and the elastic coefficient ratio of each layer is 1:2.5:

4. The three - stage elastic deformation groove is connected with the slope transmission component in an embedded coupling manner. The bottom of the slope transmission component contacts the first - stage elastic deformation groove of the three - stage elastic deformation groove. The middle part of the slope transmission component contacts the second - stage elastic deformation groove of the three - stage elastic deformation groove through the guide groove. The top of the slope transmission component is rigidly fixed to the third - stage elastic deformation groove of the three - stage elastic deformation groove.

4. A flexible pressure hydraulic press according to claim 1, characterized in that, The PID parameters of the intelligent control system are optimized online through the following formula: , where K p0 and K i0 are the reference values of the PID parameters, determined by offline calibration, λ is the attenuation factor (unit: s -1 ), configured according to the system response time; γ is the pressure correction coefficient (unit: Pa -1 ), satisfying; ; ΔP is the deviation between the set pressure (P set ), and the actual instantaneous pressure (P i ), where ΔP = P set - P i (unit: Pa).

5. A flexible pressure hydraulic press according to claim 1, characterized in that: The integrated vision recognition module uses a convolutional neural network (CNN) to extract the workpiece deformation characteristics, and the output resolution ≤ 0.05mm. The surface of the support seat (13) is provided with a wear - resistant ceramic coating, and the friction coefficient ≤ 0.

15.

6. The flexible pressure hydraulic press according to claim 1, wherein: The intelligent control system incorporates a dynamic load balancing algorithm to calculate the moment balance deviation of each support point through the following formula: , where and are the reaction forces of the i-th support point in the x and y directions (unit: Newton, N), x i , y i are the planar coordinates of the i-th support point (unit: m), M dev is the comprehensive moment balance deviation (unit: N·m); when M dev >M set , the multi-level leveling mechanism is triggered for secondary correction, and the moment balance deviation threshold M set is determined by the yield strength σ y of the workpiece material and the contact area A: , where L is the length of the die module in contact with the workpiece (unit: m).

7. A flexible pressure hydraulic press according to claim 1, wherein: The force analysis and leveling module is data - fused with the integrated vision recognition module, and the equivalent deformation compensation amount δ of the workpiece is calculated by the following formula eq： ， where, δ is the deformation of the workpiece detected by the vision system (unit: meter); is the vertical force on the i-th support point (unit: Newton); α and β are weight coefficients, satisfying α + β = 1; L1 is the characteristic length of the workpiece (unit: meter); the equivalent deformation compensation amount δ eq is converted into a pressing angle correction amount Δθ through the proportionality coefficient k to drive the flexible pressing component for secondary adjustment.

8. A flexible pressure hydraulic press according to claim 1, characterized in that: During the overload protection stage, the intelligent control system automatically selects the priority locking points according to the force distribution, and the locking sequence is determined by the following criteria: , where α and β are weight coefficients satisfying α + β = 1 and meeting the condition: , where F x,i is the real-time load of the i-th support point; is the local stress at the i-th support point; represents the effective bearing area of the i-th support point (unit: m²); σ y is the material yield strength; is the maximum load allowed for a single support point.

9. A control method for using the flexible pressure hydraulic press described in claim 4 above, characterized in that, It includes the following steps: [[ID= ​ ​

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